記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Monitoring the progression of idiopathic pulmonary fibrosis (IPF) using CT primarily focuses on assessing the extent of fibrotic lesions, without considering the distortion of lung architecture. OBJECTIVES: To evaluate three-dimensional average displacement (3D-AD) quantification of lung structures using deformable registration of serial CT images as a parameter of local lung architectural distortion and predictor of IPF prognosis. MATERIALS AND METHODS: Patients with IPF evaluated between January 2016 and March 2017 who had undergone CT at least twice were retrospectively included (n = 114). The 3D-AD was obtained by deformable registration of baseline and follow-up CT images. A computer-aided quantification software measured the fibrotic lesion volume. Cox regression analysis evaluated these variables to predict mortality. RESULTS: The 3D-AD and the fibrotic lesion volume change were significantly larger in the subpleural lung region (5.2 mm (interquartile range (IQR): 3.6-7.1 mm) and 0.70% (IQR: 0.22-1.60%), respectively) than those in the inner region (4.7 mm (IQR: 3.0-6.4 mm) and 0.21% (IQR: 0.004-1.12%), respectively). Multivariable logistic analysis revealed that subpleural region 3D-AD and fibrotic lesion volume change were independent predictors of mortality (hazard ratio: 1.12 and 1.23; 95% confidence interval: 1.02-1.22 and 1.10-1.38; p = 0.01 and p < 0.001, respectively). CONCLUSIONS: The 3D-AD quantification derived from deformable registration of serial CT images serves as a marker of lung architectural distortion and a prognostic predictor in patients with IPF.

DOI： 10.3390/diagnostics14151650

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The frequency of cardiac amyloidosis potentially present in patients with atrial fibrillation (AF) remains unclear. The purpose of this study is to determine the frequency and clinical characteristics of cardiac amyloidosis latent in AF by performing cardiac magnetic resonance imaging (MRI) in patients scheduled for AF ablation. We retrospectively analyzed 193 consecutive patients who underwent CA and cardiac MRI for atrial fibrillation. The primary endpoint of the study was the frequency of histologically confirmed cardiac amyloidosis or suspected cardiac amyloidosis [positive imaging findings on cardiac MRI strongly suspecting cardiac amyloidosis (diffuse subendocardial late gadolinium enhancement or MRI-derived extracellular volume of > 0.40)]. Among the 193 patients, 8 were confirmed or suspected cases of cardiac amyloidosis, representing a frequency of 4% (8/193 patients). Multivariate analysis identified interventricular septal thickness at end-diastole (LVSd) as an independent and significant predictor of cardiac amyloidosis (OR: 1.72, 95% CI 1.12-2.87, p = 0.020).The optimal cut-off value for IVSd was determined to be > 12.9 mm based on the Youden index. At this cut-off, the sensitivity was 75.0% (95% CI 34.9-96.8%) and the specificity was 92.3% (95% CI 87.4-95.7%), allowing for the identification of patients with definite or suspected cardiac amyloidosis. The frequency of confirmed and suspected cases of cardiac amyloidosis among patients with an IVSd > 12.9 mm was 30% (6/20 patients). In addition, prevalence of biopsy-proven cardiac amyloidosis was 10% (2/20). The prevalence of cardiac amyloidosis in atrial fibrillation patients scheduled for ablation with cardiac hypertrophy is not negligible.

DOI： 10.1007/s00380-024-02447-w

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The prognostic implications of late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI) in the context of cardiac sarcoidosis (CS) have attracted considerable attention. Nevertheless, a subset of studies has undistinguished confirmed and suspected CS cases, thereby engendering interpretative ambiguities. In this meta-analysis, we evaluated the differences in cardiac MRI findings and their prognostic utility between confirmed and suspected CS. A literature search was conducted using PubMed, Web of Science, and Cochrane libraries to compare the findings of cardiac MRI and its prognostic value in CS and suspected CS. A meta-analysis was performed to compare the prevalence of LGE MRI, odds ratios, and hazard ratios for predicting cardiac events in both groups. A total of 21 studies encompassing 24 different populations were included in the meta-analysis (CS: 393 cases, suspected CS: 2151 cases). CS had a higher frequency of LGE of the left ventricle (87.2% vs. 36.4%, p < 0.0001) and right ventricle (62.1% vs. 23.8%, p = 0.04) than suspected CS. In patients with suspected CS, the presence of left ventricular LGE was associated with higher all-cause mortality [odds ratio: 5.70 (95%CI: 2.51-12.93), p < 0.0001, I2 = 8%, p for heterogeneity = 0.37] and ventricular arrhythmia [odds ratio: 15.51 (95%CI: 5.65-42.55), p < 0.0001, I2 = 0, p for heterogeneity = 0.94]. In contrast, in CS, not the presence but extent of left ventricular LGE was a significant predictor of outcome (hazard ratio = 1.83 per 10% increase of %LGE (95%CI: 1.43-2.34, p < 0.001, I2 = 15, p for heterogeneity = 0.31). The presence of left ventricular LGE was a strong prognostic factor in suspected sarcoidosis. However, the extremely high prevalence of left ventricular LGE in confirmed CS suggests that the quantitative assessment of LGE is useful for prognostic estimation.

DOI： 10.1007/s10554-024-03191-y

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

An 87-year-old woman was hospitalized for liver abscesses and cholangitis due to common bile duct stones. She developed worsening anemia and abdominal pain. Contrast-enhanced computed tomography revealed an intrahepatic pseudoaneurysm and an arteriovenous fistula between the hepatic arteries and inferior vena cava. The initial endovascular treatment was transarterial embolization. The pseudoaneurysm was embolized with an N-butyl-2-cyanoacrylate mixture, and the inflow arteries of the arteriovenous fistula were embolized with microcoils. However, the residual perfusion of the arteriovenous fistula remained. A second endovascular treatment was performed using the transarterial and transvenous approaches. The inflow arteries were embolized using microcoils and gelatin sponges and the dominant outflow vein was embolized using microcoils, resulting in the disappearance of the perfusion in the arteriovenous fistula.

DOI： 10.22575/interventionalradiology.2023-0046

PubMed

researchmap

記述言語：英語  

DOI： 10.1002/ehf2.14919

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We aimed to identify computed tomography (CT) radiomics features that are associated with cellular infiltration and construct CT radiomics models predictive of cellular infiltration in patients with fibrotic ILD. MATERIALS AND METHODS: CT images of patients with ILD who underwent surgical lung biopsy (SLB) were analyzed. Radiomics features were extracted using artificial intelligence-based software and PyRadiomics. We constructed a model predicting cell counts in histological specimens, and another model predicting two classifications of higher or lower cellularity. We tested these models using external validation. RESULTS: Overall, 100 patients (mean age: 62 ± 8.9 [standard deviation] years; 61 men) were included. The CT radiomics model used to predict cell count in 140 histological specimens predicted the actual cell count in 59 external validation specimens (root-mean-square error: 0.797). The two-classification model's accuracy was 70% and the F1 score was 0.73 in the external validation dataset including 30 patients. CONCLUSION: The CT radiomics-based model developed in this study provided useful information regarding the cellular infiltration in the ILD with good correlation with SLB specimens.

DOI： 10.1007/s11604-024-01607-2

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

Background

PET/CT imaging with Zirconium-89 labeled [89Zr]Zr-DFO-girentuximab, which targets tumor antigen CAIX, may aid in the differentiation and characterization of clear cell renal cell carcinomas (RCC) and other renal and extrarenal lesions, and has been studied in European and American cohorts. We report results from a phase I study that evaluated the safety profile, biodistribution, and dosimetry of [89Zr]Zr-DFO-girentuximab in Japanese patients with suspected RCC.

Methods

Eligible adult patients received 37 MBq (± 10%; 10 mg mass dose) of intravenous [89Zr]Zr-DFO-girentuximab. Safety and tolerability profile was assessed based on adverse events, concomitant medications, physical examination, vital signs, hematology, serum chemistry, urinalysis, human anti-chimeric antibody measurement, and 12-lead electrocardiograms at predefined intervals. Biodistribution and normal organ and tumor dosimetry were evaluated with PET/CT images acquired at 0.5, 4, 24, 72 h and Day 5 ± 2 d after administration.

Results

[89Zr]Zr-DFO-girentuximab was administered in six patients as per protocol. No treatment-emergent adverse events were reported. Dosimetry analysis showed that radioactivity was widely distributed in the body, and that the absorbed dose in healthy organs was highest in the liver (mean ± standard deviation) (1.365 ± 0.245 mGy/MBq), kidney (1.126 ± 0.190 mGy/MBq), heart wall (1.096 ± 0.232 mGy/MBq), and spleen (1.072 ± 0.466 mGy/MBq). The mean effective dose, adjusted by the radioactive dose administered, was 0.470 mSv/MBq. The radiation dose was highly accumulated in the targeted tumor, while any abnormal accumulation in other organs was not reported.

Conclusions

This study demonstrates that [89Zr]Zr-DFO-girentuximab administered to Japanese patients with suspected RCC has a favorable safety profile and is well tolerated and has a similar dosimetry profile to previously studied populations.

DOI： 10.1093/jjco/hyae075

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIMS: Dynamic stress computed tomography (CT) perfusion is a non-invasive method for quantifying myocardial ischemia by assessing myocardial blood flow (MBF). In this meta-analysis, we evaluated the diagnostic accuracy of dynamic CT perfusion for the detection of significant coronary artery disease (CAD) across various CT scanners, obese patients, and its prognostic value. METHODS AND RESULTS: We systematically searched PubMed, Embase, Web of Science, and Cochrane library for published studies evaluating the accuracy of CT myocardial perfusion in diagnosing functional significant ischemia by invasive fractional flow reserve. The diagnostic performance of dynamic CT perfusion in detecting ischemia was evaluated using a summary receiver operating characteristic (sROC) curve. A total of 23 studies underwent meta- analysis. In myocardial region without ischemia, MBF was measured at 1.44 ml/min/g (95% confidence interval [CI]: 1.13-1.75), while in region with ischemia, it was 0.94 ml/min/g (95% CI: 0.80-1.08) (p<0.001). On the patient-based analysis, the area under the sROC curve of CT-MBF was 0.93, with a sensitivity of 0.84 and specificity of 0.88. Differences in CT type (dual source vs. single source), and body mass index (BMI) did not significantly affect the diagnostic performance. The pooled hazard ratio of dynamic CT perfusion for predicting adverse events was 4.98 (95%CI: 2.08-11.93, p=<0.001, I2=61%, p for heterogeneity = 0.07). CONCLUSIONS: Dynamic CT perfusion has high diagnostic performance in the quantitative assessment of ischemia and detection of functional myocardial ischemia as defined by invasive FFR, and may be useful in risk stratification of CAD patients.

DOI： 10.1093/ehjci/jeae118

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: To evaluate the clinical utility of feature tracking (FT)-derived myocardial strain in patients with non-ischaemic dilated cardiomyopathy (NIDCM). MATERIALS AND METHODS: Electronic database searches of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE were performed. Studies on NIDCM were divided into categories according to left ventricular ejection fraction (LVEF; <30%, 30-40%, >40%), and correlations between strains and prevalence of late gadolinium enhancement (LGE) were evaluated by weighted correlation coefficients. Global longitudinal strain (GLS) hazard ratios were also integrated for prediction of future adverse events. RESULTS: The present meta-analysis analysed data from 5,767 patients with NIDCM from 30 eligible studies. GLS and global circumferential strain significantly differed across the three LVEF categories (all p<0.05); however, global radial strain did not. Only GLS showed a strong correlation with the prevalence of LGE (Spearman's correlation coefficient = 0.61). The pooled HR of GLS for predicting adverse events was 1.15 (95% confidence interval [CI]: 1.07-1.23, p<0.001). CONCLUSION: In this meta-analysis, FT-derived GLS was strongly correlated with myocardial fibrosis and was an important predictor of future adverse events. These results suggest that FT-derived GLS may be useful in the pathological evaluation and risk stratification of NIDCM.

DOI： 10.1016/j.crad.2023.12.029

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Despite advancements in coronary computed tomography angiography (CTA), challenges in positive predictive value and specificity remain due to limited spatial resolution. The purpose of this experimental study was to investigate the effect of 2nd generation deep learning-based reconstruction (DLR) on the quantitative and qualitative image quality in coronary CTA. METHODS: A vessel model with stepwise non-calcified plaque was scanned using 320-detector CT. Image reconstruction was performed using four techniques: hybrid iterative reconstruction (HIR), model-based iterative reconstruction (MBIR), DLR, and 2nd generation DLR. The luminal peak CT number, contrast-to-noise ratio (CNR), and edge rise slope (ERS) were quantitatively evaluated via profile curve analysis. Two observers qualitatively graded the graininess, lumen sharpness, and overall lumen visibility on the basis of the degree of confidence for the stenosis severity using a five-point scale. RESULTS: The image noise with HIR, MBIR, DLR, and 2nd generation DLR was 23.0, 21.0, 16.9, and 9.5 HU, respectively. The corresponding CNR (25% stenosis) was 15.5, 15.9, 22.1, and 38.3, respectively. The corresponding ERS (25% stenosis) was 203.2, 198.6, 228.9, and 262.4 HU/mm, respectively. Among the four reconstruction methods, the 2nd generation DLR achieved the significantly highest CNR and ERS values. The score of 2nd generation DLR in all evaluation points (graininess, sharpness, and overall lumen visibility) was higher than those of the other methods (overall vessel visibility score, 2.6±0.5, 3.8±0.6, 3.7±0.5, and 4.6±0.5 with HIR, MBIR, DLR, and 2nd generation DLR, respectively). CONCLUSIONS: 2nd generation DLR provided better CNR and ERS in coronary CTA than HIR, MBIR, and previous-generation DLR, leading to the highest subjective image quality in the assessment of vessel stenosis.

DOI： 10.21037/qims-23-1204

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

Background

CAD-RADS (Coronary Artery Disease-Reporting and Data System) is a standardized reporting system that offers a structured method for interpreting and reporting results obtained through coronary computed tomography angiography (CTA), and it has been deemed useful in the prognostication of patients with suspected coronary artery disease (CAD).

Purpose

The present meta-analysis sought to assess the prognostic value of CAD-RADS in individuals with suspected CAD.

Materials and Methods

We conducted a systematic search of the electronic databases of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE. A random-effects model was implemented to evaluate the pooled hazard ratio (HR) for each CAD-RADS categories and area under the receiver operating characteristics curve (AUC) for predicting major adverse cardiovascular events (MACE).

Results

Data from 37,596 coronary CTA examinations from 13 studies were analysed. During follow-up, 2,536 (6.7%) adverse events were observed. Pooled HRs for prediction of adverse events were significant for all CAD-RADS categories, with incremental increase in HRs with progressively higher categories. For prediction of all-cause mortality, all categories except CAD-RADS 1 showed significant HR compared to CAD-RADS 0. Combination of CAD-RADS to conventional clinical risk factors and CAC resulted in a high predictive capacity for adverse events (pooled AUC: 0.82 ([95% CI: 0.73-0.91]).

Conclusion

The CAD-RADS category imparts information on the CAD severity, and shows incremental increase in HR for adverse events with progressively higher categories, especially beyond CAD-RADS4b.

DOI： 10.1093/radadv/umae007

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: This prospective multicenter study assessed the prevalence of myocardial injury in patients with COVID-19 using cardiac magnetic resonance imaging (CMR).Methods and Results: We prospectively screened 505 patients with moderate to severe COVID-19 disease from 7 hospitals in Japan. Of these patients, 31 (mean [±SD] age 63.5±10.4 years, 23 [74%] male) suspected of myocardial injury, based on elevated serum troponin or B-type natriuretic peptide concentrations either upon admission or 3 months after discharge, underwent CMR 3 months after discharge. The primary endpoint was the presence of myocardial injury, defined by any of the following: (1) contrast enhancement in the left or right ventricle myocardium on late gadolinium enhancement CMR; (2) left or right ventricular dysfunction (defined as <50% and <45%, respectively); and (3) pericardial thickening on contrast enhancement. The mean (±SD) duration between diagnosis and CMR was 117±16 days. The primary endpoint was observed in 13 of 31 individuals (42%), with 8 (26%) satisfying the modified Lake Louise Criteria for the diagnosis of acute myocarditis. CONCLUSIONS: This study revealed a high incidence of myocardial injury identified by CMR in patients with moderate to severe COVID-19 and abnormal findings for cardiac biomarkers.

DOI： 10.1253/circj.CJ-23-0729

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

INTRODUCTION: Primary small bowel carcinoma in pregnant women is extremely rare. Small bowel cancer is difficult to diagnose because of its rarity, lack of specific clinical symptoms, and particular anatomical features. We experienced a case of primary small bowel adenocarcinoma with ovarian metastasis during pregnancy. This is the first reported case of a patient with small bowel adenocarcinoma whose pregnancy continued to term and ended in delivery. CASE PRESENTATION: A 32-year-old pregnant woman developed abdominal pain, and imaging examination revealed an ovarian tumor at 29 weeks of gestation. We performed laparotomy and resected the ovarian tumor, which was initially suspected to be primary ovarian cancer. The patient continued the pregnancy to term. A detailed examination of the abdominal cavity during cesarean delivery at 37 weeks revealed that the primary lesion was located in the small bowel. CONCLUSION: It is important to recognize that the small bowel may be the primary site of metastatic ovarian cancer. Detailed and careful examination is necessary to diagnose small bowel cancer during pregnancy.

DOI： 10.1159/000540524

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Spinal cord injury is difficult to detect directly on postmortem computed tomography (PMCT) and it is usually diagnosed by indirect findings such as a hematoma in the spinal canal. However, we have encountered cases where the hematoma-like high-attenuation area in the cervical spinal canal was visible on PMCT, while no hematoma was observed at autopsy; we called it a "pseudo hematoma in the cervical spinal canal (pseudo-HCSC)." In this retrospective study, we performed statistical analysis to distinguish true from pseudo-HCSC. The cervical spinal canal was dissected in 35 autopsy cases with a hematoma-like high-attenuation area (CT values 60-100 Hounsfield Unit (HU)) in the spinal canal from the first to the fourth cervical vertebrae in axial slices of PMCT images. Of these 22 had a hematoma and 13 did not (pseudo-HCSC). The location and length of the hematoma-like high-attenuation and spinal cord areas were assessed on reconstructed PMCT images, true HCSC cases had longer the posterior hematoma-like area and shorter the spinal cord area in the midline of the spinal canal (P < 0.05). Furthermore, we found that true HCSC cases were more likely to have fractures and gases on PMCT while pseudo-HCSC cases were more likely to have significant facial congestion (P < 0.05). We suggest that pseudo-HCSC on PMCT is related to congestion of the internal vertebral venous plexus. This study raises awareness about the importance of distinguishing true HCSC from pseudo-HCSC in PMCT diagnosis, and it also presents methods for differentiation between these two groups.

DOI： 10.1016/j.legalmed.2023.102358

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: The objective of this meta-analysis was to assess the clinical utility of anomalous discoveries on cardiac magnetic resonance, particularly the right ventricular extracellular volume (RV-ECV), among individuals who underwent surgical repair for Tetralogy of Fallot (rTOF). METHODS: We conducted a systematic search of electronic databases including PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE. Our analysis involved a comparison of ECV levels between rTOF patients and controls, as well as an evaluation of the predictive value of ECV for future adverse events. RESULTS: We identified 16 eligible studies that encompassed 856 rTOF patients and 283 controls. Our meta-analysis showed a significant increase in LV-ECV among rTOF patients compared to control subjects (MD = 2.63, 95%CI: 1.35 to 3.90, p < 0.0001, I2 = 86%, p for heterogeneity < 0.00001). Moreover, RV-ECV was found to be substantially higher in patients compared to LV-ECV. Our meta-analysis also revealed a significant association between RV-ECV and adverse events (HR = 1.15, 95% CI: 1.04 to 1.27, p = 0.005, I2 = 0%, p for heterogeneity = 0.62), while LV-ECV did not show any significant association with adverse events (HR = 1.12, 95% CI: 0.92 to 1.36, p = 0.16, I2 = 0%, p for heterogeneity = 0.46). CONCLUSION: The results of this meta-analysis on RV-ECV confirmed the presence of RV fibrosis as one of the prognostic factors in rTOF patients.

DOI： 10.1007/s00380-023-02332-y

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Computed tomography (CT)-derived extracellular volume fraction (ECV) is a noninvasive method to quantify myocardial fibrosis. Although studies suggest CT is a suitable measure of ECV, clinical use remains limited. OBJECTIVES: A meta-analysis was performed to determine the clinical value of CT-derived ECV in cardiovascular diseases. METHODS: Electronic database searches of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE were performed. The most pivotal analysis entailed the comparison of ECV ascertained through CT-ECV among the control, aortic stenosis, and cardiac amyloidosis cohorts. The diagnostic test accuracy for detecting cardiac amyloidosis was assessed using summary receiver-operating characteristics curve. RESULTS: Pooled CT-derived ECV values were 28.5% (95% CI: 27.3%-29.7%) in the control, 31.9 (95% CI: 30.2%-33.8%) in the aortic stenosis, and 48.9% (95% CI: 44.5%-53.3%) in the cardiac amyloidosis group. ECV was significantly elevated in aortic stenosis (P = 0.002; vs controls) but further elevated in cardiac amyloidosis (P < 0.001; vs aortic stenosis). CT-derived ECV had a high diagnostic accuracy for cardiac amyloidosis, with sensitivity of 92.8% (95% CI: 86.7%-96.2%), specificity of 84.8% (95% CI: 68.6%-93.4%), and area under the summary receiver-operating characteristic curve of 0.94 (95% CI: 0.88-1.00). CONCLUSIONS: This study is the first comprehensive systematic review and meta-analysis of CT-derived ECV evaluation in cardiac disease. The high diagnostic accuracy of CT-ECV suggests the usefulness of CT-ECV in the diagnosis of cardiac amyloidosis in preoperative CT planning for transcatheter aortic valve replacement.

DOI： 10.1016/j.jcmg.2023.10.008

PubMed

researchmap

記述言語：英語  

Cardiovascular complications of cancer therapy are among the most important factors affecting cancer prognosis. Cisplatin-induced aortic thrombosis is rare but can be life-threatening in the event of peripheral embolism. In this report, we describe a case of superior mesenteric artery (SMA) embolism associated with cisplatin-induced aortic thrombosis. A 66-year-old male, diagnosed with esophageal cancer, initiated systemic chemotherapy with a regimen consisting of 5-fluorouracil and cisplatin, combined with radiotherapy. After 7 days of chemoradiotherapy, the patient developed a floating thrombus in the ascending aorta and an SMA embolism; chemoradiotherapy was then discontinued. Laparoscopy revealed an ischemic small intestine that required resection; intravenous unfractionated heparin was initiated 3 days after. Computed tomography showed disappearance of the floating aortic thrombus and reduce SMA thrombus size. Early detection of cisplatin-induced aortic thrombosis may prevent fatal outcomes in symptomatic peripheral embolisms, such as SMA embolism, considering anticoagulation, and discontinuation of cisplatin-based chemotherapy may cause resolution of thrombus events.

DOI： 10.1259/bjrcr.20220149

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Although microvascular dysfunction (MVD) is considered an essential pathophysiology in patients with heart failure with preserved ejection fraction (HFpEF), the frequency and prognostic impact of MVD are not fully understood. This meta-analysis evaluated the frequency of MVD in patients with HFpEF and its utility in risk stratification. MATERIALS AND METHODS: On May 26, 2022, a literature search was performed on PubMed, Web of Science, the Cochrane library, and Embase using the search terms such as "Heart failure with preserved ejection fraction," "HFpEF," "microvascular dysfunction," and "MVD." The prevalence of MVD in patients with HFpEF was calculated using the general inverse variance method. A comprehensive literature review was conducted to examine the association between MVD and prognosis in patients with HFpEF. RESULTS: Data pertaining to a total of 941 patients diagnosed with HFpEF were extracted from the collective pool of 9 studies. The results of the meta-analysis revealed that the frequency of MVD among patients with HFpEF was found to be 55.5% (95% CI: 34.8%-76.2%), with a substantial degree of heterogeneity (I2  = 98%, p for heterogeneity <.001). Among the five studies that provided data on the association between MVD and prognosis, a significant statistical association was observed in four of them. CONCLUSIONS: This meta-analysis revealed that approximately 50% of patients diagnosed with HFpEF exhibited MVD. Moreover, the presence of MVD demonstrated significant prognostic implications in multiple studies conducted on patients with HFpEF. These findings strongly suggest that MVD plays a crucial role in the underlying pathophysiology of patients with HFpEF.

DOI： 10.1111/micc.12822

PubMed

researchmap

記述言語：英語  

In this report, we present a case of gastrointestinal bleeding due to splenic artery rupture, which required repeated transcatheter arterial embolization (TAE) within a short period of time. A 75-year-old man with pancreatic carcinoma was transported to our hospital with active hematemesis and vital signs consistent with shock. Contrast-enhanced computed tomography images showed a pancreatic tumor that had caused a pseudoaneurysm of the splenic artery to rupture. The pseudoaneurysm was embolized using only an N-butyl-2-cyanoacrylate (NBCA) and lipiodol mixture. However, hematemesis with signs of shock recurred 13 h later, and angiography showed rebleeding from the origin of the splenic artery. The splenic artery was subsequently embolized using an NBCA and lipiodol mixture. Repeated TAE finally controlled the hemorrhage; however, asymptomatic splenic infarction and hepatic infarction occurred due to nontarget embolization.

DOI： 10.22575/interventionalradiology.2022-0034

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: The purpose of this meta-analysis was to comprehensively investigate the diagnostic ability of 1.5 T and 3.0 T whole heart coronary angiography (WHCA) to detect significant coronary artery disease (CAD) on X-ray coronary angiography. METHODS: A literature search of electronic databases, including PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE, was performed to retrieve and integrate articles showing significant CAD detectability of 1.5 and 3.0 T WHCA. RESULTS: Data from 1899 patients from 34 studies were included in the meta-analysis. 1.5 T WHCA had a summary area under ROC of 0.88 in the patient-based analysis, 0.90 in the vessel-based analysis, and 0.92 in the segment-based analysis. These values for 3.0 T WHCA were 0.94, 0.95, 0.96, respectively. Contrast-enhanced 3.0 T WHCA had significantly higher specificity than non-contrast-enhanced 1.5 T WHCA on a patient-based analysis (0.87, 95% CI 0.80-0.92 vs. 0.74, 95% CI 0.64-0.82, P = 0.02). There were no differences in diagnostic performance on a patient-based analysis by use of vasodilators, beta-blockers or between Asian and Western countries. CONCLUSIONS: The diagnostic performance of WHCA was deemed satisfactory, with contrast-enhanced 3.0 T WHCA exhibiting higher specificity compared to non-contrast-enhanced 1.5 T WHCA in a patient-based analysis. There were no significant differences in diagnostic performance on a patient-based analysis in terms of vasodilator or beta-blocker use, nor between Asian and Western countries. However, further large-scale multicentre studies are crucial for the widespread global adoption of WHCA.

DOI： 10.1186/s12968-023-00949-6

PubMed

researchmap

記述言語：英語  

UNLABELLED: We present the case of a 65-year-old male with multivessel coronary spasm presumably related to coronavirus disease 2019 (COVID-19). Acetylcholine coronary angiogram and cardiac magnetic resonance imaging were used for the diagnosis. As the precise pathophysiology of myocardial injury by COVID-19 remains unclear, the multimodality approach may contribute to the accurate diagnosis. LEARNING OBJECTIVE: Myocardial involvement by severe acute respiratory syndrome coronavirus 2 infection is related to various pathologies. It is important to evaluate the degrees of cardiac damage and make a diagnosis by multimodality imaging especially with cardiac magnetic resonance.

DOI： 10.1016/j.jccase.2023.05.010

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/noajnl/vdad043

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1097/CM9.0000000000002652

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Pelvic fractures are common in cases of blunt trauma, which is strongly associated with mortality. Transcatheter arterial embolization is a fundamental treatment strategy for fatal arterial injuries caused by blunt pelvic trauma. However, vascular injuries due to blunt pelvic trauma can show various imaging findings other than arterial hemorrhage. We present a pictorial review of common and uncommon vascular injuries, including active arterial bleeding, pseudoaneurysm, arteriovenous fistula, arterial occlusion, vasospasm, and active venous bleeding. Knowledge of these vascular injuries can help clinicians select the appropriate therapeutic strategy and thus save lives.

DOI： 10.1007/s11604-022-01355-1

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Extracellular volume fraction (ECV) by cardiac magnetic resonance (CMR) allows for the non-invasive quantification of diffuse myocardial fibrosis. Texture analysis and machine learning are now gathering attention in the medical field to exploit the ability of diagnostic imaging for various diseases. This study aimed to investigate the predictive value of texture analysis of ECV and machine learning for predicting response to guideline-directed medical therapy (GDMT) for patients with non-ischemic dilated cardiomyopathy (NIDCM). A total of one-hundred and fourteen NIDCM patients [age: 63 ± 12 years, 91 (81%) males] were retrospectively analyzed. We performed texture analysis of ECV mapping of LV myocardium using dedicated software. We calculated nine histogram-based features (mean, standard deviation, maximum, minimum, etc.) and five gray-level co-occurrence matrices. Five machine learning techniques and the fivefold cross-validation method were used to develop prediction models for LVRR by GDMT based on 14 texture parameters on ECV mapping. We defined the LVRR as follows: LVEF increased ≥ 10% points and decreased LVEDV ≥ 10% on echocardiography after GDMT > 12 months. Fifty (44%) patients were classified as non-responders. The area under the receiver operating characteristics curve for predicting non-responder was 0.82 for eXtreme Gradient Boosting, 0.85 for support vector machine, 0.76 for multi-layer perception, 0.81 for Naïve Bayes, 0.77 for logistic regression, respectively. Mean ECV value was the most critical factor among texture features for differentiating NIDCM patients with LVRR and those without (0.28 ± 0.03 vs. 0.36 ± 0.06, p < 0.001). Machine learning analysis using the support vector machine may be helpful in detecting high-risk NIDCM patients resistant to GDMT. Mean ECV is the most crucial feature among texture features.

DOI： 10.1007/s00380-022-02167-z

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Phase-contrast cine cardiovascular magnetic resonance (CMR) of the coronary sinus has emerged as a non-invasive method for measuring coronary sinus blood flow and coronary flow reserve (CFR). However, its clinical utility has not yet been established. Here we performed a meta-analysis to clarify the clinical value of CMR-derived CFR in various cardiovascular diseases. METHODS: An electronic database search was performed of PubMed, Web of Science Core Collection, Cochrane Advanced Search, and EMBASE. We compared the CMR-derived CFR of various cardiovascular diseases (stable coronary artery disease [CAD], hypertrophic cardiomyopathy [HCM], dilated cardiomyopathy [DCM]) and control subjects. We assessed the prognostic value of CMR-derived CFR for predicting major adverse cardiac events (MACE) in patients with stable CAD. RESULTS: A total of 47 eligible studies were identified. The pooled CFR from our meta-analysis was 3.48 (95% confidence interval [CI], 2.98-3.98) in control subjects, 2.50 (95% CI, 2.38-2.61) in stable CAD, 2.01 (95% CI, 1.70-2.32) in cardiomyopathies (HCM and DCM). The meta-analysis showed that CFR was significantly reduced in stable CAD (mean difference [MD] = -1.48; 95% CI, -1.78 to -1.17; p < 0.001; I2 = 0%; p for heterogeneity = 0.33), HCM (MD = -1.20; 95% CI, -1.63 to -0.77; p < 0.001; I2 = 0%; p for heterogeneity = 0.49), and DCM (MD = -1.53; 95% CI, -1.93 to -1.13; p < 0.001; I2 = 0%; p for heterogeneity = 0.45). CMR-derived CFR was an independent predictor of MACE for patients with stable CAD (hazard ratio = 0.52 per unit increase; 95% CI, 0.37-0.73; p < 0.001; I2 = 84%, p for heterogeneity < 0.001). CONCLUSIONS: CMR-derived CFR was significantly decreased in cardiovascular diseases, and a decreased CFR was associated with a higher occurrence of MACE in patients with stable CAD. These results suggest that CMR-derived CFR has potential for the pathological evaluation of stable CAD, cardiomyopathy, and risk stratification in CAD.

DOI： 10.1186/s12968-023-00912-5

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.5603/CJ.a2023.0004

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.21037/qims-22-522

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

We investigated the feasibility of a new deep-learning (DL)-based lung analysis method for the evaluation of interstitial lung disease (ILD) by comparing it with evaluation using the traditional computer-aided diagnosis (CAD) system and patients’ clinical outcomes. We prospectively included 104 patients (84 with and 20 without ILD). An expert radiologist defined regions of interest in the typical areas of normal, ground-glass opacity, consolidation, consolidation with fibrosis (traction bronchiectasis), honeycombing, reticulation, traction bronchiectasis, and emphysema, and compared them with the CAD and DL-based analysis results. Next, we measured the extent of ILD lesions with the CAD and DL-based analysis and compared them. Finally, we compared the lesion extent on computed tomography (CT) images, as measured with the DL-based analysis, with pulmonary function tests results and patients’ overall survival. Pearson’s correlation analysis revealed a significant correlation between DL-based analysis and CAD results. Forced vital capacity was significantly correlated with DL-based analysis (r = 0.789, p &lt; 0.001 for normal lung volume and r = −0.316, p = 0.001 for consolidation with fibrosis volume). Consolidation with fibrosis measured using DL-based analysis was independently associated with poor survival. The lesion extent measured using DL-based analysis showed a negative correlation with the pulmonary function test results and prognosis.

DOI： 10.3390/diagnostics12123038

researchmap

記述言語：英語  

DOI： 10.1016/j.ejim.2022.08.028

PubMed

researchmap

記述言語：英語  

DOI： 10.1002/ehf2.14095

PubMed

researchmap

記述言語：英語  

DOI： 10.1002/ehf2.14236

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Percutaneous transhepatic stent-graft placement usually requires more than a 12 F sheath, which has a higher potential risk of peritoneal hemorrhage. A case of postoperative portal vein hemorrhage after pancreaticoduodenectomy treated using a Viabahn VBX balloon expanding stent-graft is described in this report. The stent-graft was delivered using an 8 F sheath through a transhepatic approach and deployed from the superior mesenteric vein to the main portal vein. Hemostasis was achieved and graft patency was confirmed one year after the procedure.

DOI： 10.1080/13645706.2022.2056706

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The previous study has shown that the contrast defect of the left atrial appendage (LAA) on contrast-enhanced cardiac computed tomography (CT) is associated with a higher rate of stroke in patients with atrial fibrillation (AF). This study aimed to investigate the association between LAA CT contrast defect and the risk of arrhythmia recurrence after catheter ablation (CA) in patients with paroxysmal AF. A total of 283 paroxysmal AF patients [age: 67 ± 10 years, 185 (65%) males] who underwent cardiac CT before CA were retrospectively analyzed. The presence or absence of LAA CT contrast defect was visually assessed using early phase CT images. Recurrence was an episode of atrial arrhythmia beyond the first 90 days post-ablation. LAA flow velocity was measured using transesophageal echocardiography in 246 paroxysmal AF patients. Sixty-eight (24%) patients had an LAA CT contrast defect. LAA flow velocity was significantly reduced in patients with LAA CT defect compared to those without (56.8 ± 28.7 cm/s vs. 41.1 ± 19.1 cm/s, p < 0.001). During a median follow-up period of 858 days, arrhythmia recurrence was identified in 85 (30%) patients. On a Kaplan Meier curve, patients with LAA CT contrast defect had significantly higher recurrence rates than those without (p = 0.043). On a multivariable Cox regression analysis, LAA CT contrast defect was a significant and independent predictor after adjustment of age, sex and left atrial volume index (hazard ratio: 1.79, 95% confidence interval: 1.03-3.07, p = 0.036). LAA CT contrast defect was associated with decreased LAA flow velocity and a higher rate of arrhythmia recurrence after CA, suggesting its usefulness as a non-invasive predictor for high-risk AF patients resistant to CA therapy.

DOI： 10.1007/s00380-022-02166-0

PubMed

researchmap

記述言語：英語  

DOI： 10.1016/j.hjc.2022.07.004

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In this systematic review and meta-analysis, we sought to evaluate the prevalence of cardiac involvement in patients with COVID-19 using cardiac magnetic resonance imaging. A literature review was performed to investigate the left ventricular (LV) and right ventricular (RV) ejection fraction (EF), the prevalence of LV late gadolinium enhancement (LGE), pericardial enhancement, abnormality on T1 mapping, and T2 mapping/T2-weighted imaging (T2WI), and myocarditis (defined by modified Lake Louis criteria). Pooled mean differences (MD) between COVID-19 patients and controls for LVEF and RVEF were estimated using random-effects models. We included data from 10.462 patients with COVID-19, comprising 1.010 non-athletes and 9.452 athletes from 29 eligible studies. The meta-analysis showed a significant difference between COVID-19 patients and controls in terms of LVEF [MD = - 2.84, 95% confidence interval (CI) - 5.11 to - 0.56, p < 0.001] and RVEF (MD = - 2.69%, 95% CI - 4.41 to - 1.27, p < 0.001). However, in athletes, no significant difference was identified in LVEF (MD = - 0.74%, 95% CI - 2.41 to - 0.93, p = 0.39) or RVEF (MD = - 1.88%, 95% CI - 5.21 to 1.46, p = 0.27). In non-athletes, the prevalence of LV LGE abnormalities, pericardial enhancement, T1 mapping, T2 mapping/T2WI, myocarditis were 27.5% (95%CI 17.4-37.6%), 11.9% (95%CI 4.1-19.6%), 39.5% (95%CI 16.2-62.8%), 38.1% (95%CI 19.0-57.1%) and 17.6% (95%CI 6.3-28.9%), respectively. In athletes, these values were 10.8% (95%CI 2.3-19.4%), 35.4% (95%CI - 3.2 to 73.9%), 5.7% (95%CI - 2.9 to 14.2%), 1.9% (95%CI 1.1-2.7%), 0.9% (0.3-1.6%), respectively. Both LVEF and RVEF were significantly impaired in COVID-19 patients compared to controls, but not in athletes. In addition, the prevalence of myocardial involvement is not negligible in patients with COVID-19.

DOI： 10.1007/s00380-022-02055-6

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Obesity paradoxes have been reported in many diseases to date. As the wording "paradox" indicates, our intuition rejects the hypothesis that obese people have a better life expectancy or fewer cardiovascular events. One of the most plausible explanations for the obesity paradox is collider bias, but controversy about this is ongoing. If the findings of the original research are affected by collider bias, meta-analyses of that research will also be affected by the same bias. It is to be hoped that the use of appropriate analytical techniques will enable the true nature of the obesity bias to become clear.

DOI： 10.1093/nutrit/nuac077

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

ABSTRACT: Intraductal papilloma (IDP) is a benign tumor of the breast. However, IDP has been reported to show high uptake of 18F-FDG using whole-body PET. We experienced IDP with low-grade ductal carcinoma in situ using dedicated breast PET, which is more sensitive than whole-body PET. The 18F-FDG uptake of the whole tumor was high, and differentiation between the carcinoma and the residual benign lesion was difficult. This is the first report of IDP detected with dedicated breast PET. Diagnosis of IDP is sometimes controversial; papilloma may show glucose uptake similar to that of low-grade carcinoma.

DOI： 10.1097/RLU.0000000000004086

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND/PURPOSE: The detection ability and role of different imaging modalities to detect pancreatic neuroendocrine neoplasms (PNENs) including small lesions is unclear. This study aimed to compare the ability of endoscopic ultrasound (EUS) and computed tomography (CT) to detect PNENs. METHODS: Data of patients who underwent EUS and contrast-enhanced CT and were diagnosed with PNENs were analyzed. The detection rates of pancreatic lesions with EUS and CT based on tumor size and influencing factors were investigated. RESULTS: For 256 PNEN lesions, the detection rate of EUS was better than that of CT (94.5% vs. 86.3%; p < 0.001). EUS was significantly superior to CT for PNENs ≤ 5 mm (58.3% vs 16.7%; p = 0.006) and 5-10 mm (97.7% vs 79.5%; p = 0.008). There was no significant difference in the detection rate between EUS and CT for PNENs > 10 mm (98.4% vs 96.4%; p = 0.375). Size (≤ 5 mm) and insulinoma were independent factors associated with poor EUS and CT detection rates. CONCLUSIONS: EUS exhibited better detection ability than CT, with an excellent detection rate for PNENs > 5 mm, except for insulinomas. CT could detect PNENs > 10 mm, which are amenable to treatment.

DOI： 10.1002/jhbp.1144

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A recent study has shown that the heterogeneity of native T1 mapping may be a new prognostic factor for patients with non-ischemic dilated cardiomyopathy (NIDCM). This study aimed to investigate the predictive value of native T1 heterogeneity of the left ventricular (LV) myocardium, as assessed by pixel-wise histogram analysis, for predicting left ventricular reverse remodeling (LVRR) by medical therapy in patients with NIDCM. A total of one hundred and thirteen NIDCM patients (mean age: 63 ± 12 years; 91 males and 22 females; mean LV ejection fraction (EF): 37 ± 10%) were retrospectively analyzed. T1 mapping images were acquired using a modified look-locker inversion recovery (MOLLI) sequence. We performed histogram analysis of native T1 mapping of LV myocardium, mean (T1-mean) and standard deviation (T1-STD) of native T1 time from each pixel were calculated. Extracellular volume fraction (ECV) was also evaluated. LVRR was defined as LVEF increased ≥ 10% points and decrease in LV end-diastolic volume ≥ 10% at 12 months from initiation of medical therapy. Cutoff value of T1-mean and T1-STD was set as median value of each parameter. Sixty (53%) NIDCM patients reached LVRR. Area under the receiver-operating characteristics curve for predicting LVRR was 0.763 (95% confidence interval (CI) 0.679-0.847) for %LGE, 0.757 (95% CI 0.663-0.850) for T1-mean, 0.724 (95% CI 0.625-0.823) for T1-STD, 0.800 (95% CI 0.717-0.882) for ECV, respectively. Proportion of LVRR was significantly lower in NIDCM patients with high T1-mean and high T1-STD (12%) compared to NIDCM with high T1-mean and low T1-STD (65%) (p < 0.001). Adding T1-STD to T1-mean improved AUC from 0.757 to 0.806, comparable to AUC of ECV. Combination of T1-mean and T1-STD, a parameter of heterogeneity of native T1 of the LV myocardium, may be a useful for prediction of LVRR by medical therapy without use of gadolinium contrast for patients with NIDCM.

DOI： 10.1007/s00380-022-02057-4

PubMed

researchmap

記述言語：英語  

DOI： 10.1016/j.amjcard.2022.02.010

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

In this study, we first developed an artificial intelligence (AI)-based algorithm for classifying chest computed tomography (CT) images using the coronavirus disease 2019 Reporting and Data System (CO-RADS). Subsequently, we evaluated its accuracy by comparing the calculated scores with those assigned by radiologists with varying levels of experience. This study included patients with suspected SARS-CoV-2 infection who underwent chest CT imaging between February and October 2020 in Japan, a non-endemic area. For each chest CT, the CO-RADS scores, determined by consensus among three experienced chest radiologists, were used as the gold standard. Images from 412 patients were used to train the model, whereas images from 83 patients were tested to obtain AI-based CO-RADS scores for each image. Six independent raters (one medical student, two residents, and three board-certified radiologists) evaluated the test images. Intraclass correlation coefficients (ICC) and weighted kappa values were calculated to determine the inter-rater agreement with the gold standard. The mean ICC and weighted kappa were 0.754 and 0.752 for the medical student and residents (taken together), 0.851 and 0.850 for the diagnostic radiologists, and 0.913 and 0.912 for AI, respectively. The CO-RADS scores calculated using our AI-based algorithm were comparable to those assigned by radiologists, indicating the accuracy and high reproducibility of our model. Our study findings would enable accurate reading, particularly in areas where radiologists are unavailable, and contribute to improvements in patient management and workflow.

DOI： 10.3390/diagnostics12030738

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: The present prospective phase 1/2 study aimed to elucidate the efficacy and safety of 177 Lu-DOTATATE (four cycles of 7.4 GBq) in Japanese patients with unresectable, progressive neuroendocrine tumors (NETs). METHODS: From April 2018 to October 2020, 15 patients with advanced NETs (five midgut, eight pancreatic, and two lung NETs) were enrolled. Objective response rate (ORR), progression-free survival (PFS), and adverse events (AEs) were evaluated. Pharmacokinetics and dosimetry were also evaluated in three midgut patients. RESULTS: The mean absorbed doses of 177 Lu-DOTATATE to the kidneys (20.7 Gy/29.6 GBq) and the bone marrow (0.631 Gy/29.6 GBq) were within the radiation tolerance doses. The ORR of the whole population was 53% (90% CI, 30%-76%). ORRs of the midgut and non-midgut NETs were 60% (90% CI, 19%-92%) and 50% (90% CI, 22%-78%), respectively. There was no difference in the maximum reduction rate of the sum of the target lesion diameters between patients with midgut and non-midgut NET. The median PFS was not reached; the PFS rate at 52 weeks was 80% (90% CI, 56.1%-91.7%). AEs of Grade 3 or higher were lymphopenia (47%) and leukopenia (7%). CONCLUSION: 177 Lu-DOTATATE demonstrated remarkable tumor shrinkage and tolerability in Japanese patients with advanced NETs.

DOI： 10.1002/jhbp.1101

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: As percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) gains wider acceptance as a therapeutic option for coronary artery disease, the importance of appropriate patient selection has increased. Although cardiovascular magnetic resonance imaging (MRI) allows segmental and quantitative analyses of myocardial ischemia and scar transmurality, it has limitations, including contraindications, cost, and accessibility. This study established a non-invasive method to evaluate patients undergoing CTO-PCI using two-dimensional speckle-tracking echocardiography (2D-STE). METHODS: Overall, we studied 55 patients who underwent successful CTO-PCI. Cardiovascular MRI and 2D-STE were performed before and 8 ± 2 months after CTO-PCI. Segmental findings of strain parameters were compared with those obtained with late gadolinium enhancement and stress-perfusion MRI. RESULTS: With a cutoff of -10.7, pre-procedural circumferential strain (CS) showed reasonable sensitivity (71%) and specificity (73%) for detecting segments with transmural scar. The discriminatory ability of longitudinal strain (LS) for segments with transmural scar significantly improved during follow-up after successful CTO-PCI in the territory of the recanalized artery (area under the curve (AUC) 0.70 vs. 0.80, p < 0.001). LS accuracy was lower than that of CS at baseline (AUC 0.70 vs. 0.79, p = 0.048), and was increased at follow-up (AUC 0.80 vs. 0.82, p = 0.81). Changes in myocardial perfusion reserve from baseline to follow-up were significantly associated with those in LS but not in CS. CONCLUSIONS: Use of 2D-STE may allow the non-invasive evaluation of patients undergoing CTO-PCI to assess the indication before the procedure and treatment effects at follow-up.

DOI： 10.3390/jcm10204712

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Coronary microvascular dysfunction (CMD) has been proposed as a novel mechanism for the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). Recent studies have suggested the potential utility of coronary flow reserve (CFR) as a marker of CMD in patients with HFpEF. Phase contrast (PC) cine cardiovascular magnetic resonance (CMR) of the coronary sinus has emerged as a non-invasive method to quantify CFR. We aimed to investigate the prognostic value of CMR-derived CFR in patients with HFpEF. METHODS: Data from 163 HFpEF patients (73 ± 9 years; 86 [53%] female) were retrospectively analyzed. Coronary sinus blood flow was measured in all patients, and myocardial blood flow was calculated as coronary sinus blood flow divided by left ventricular mass. CFR was calculated as the myocardial blood flow during adenosine triphosphate infusion divided by that at rest. Adverse events were defined as all-cause death and hospitalization due to HF exacerbation. Event-free survival stratified according to CFR < 2.0 was estimated with Kaplan-Meier survival methods and Log-rank test. RESULTS: During a median follow-up of 4.1 years, 26 patients (16%) experienced adverse events. CMR-derived CFR was significantly lower in HFpEF with adverse events compared with those without (1.93 ± 0.38 vs. 2.67 ± 0.52, p < 0.001). On a Kaplan Meier curve, the rates of adverse events were significantly higher in HFpEF patients with CFR < 2.0 compared with HFpEF with CFR ≥ 2.0 (p < 0.001). The area under the curve of CFR for predicting adverse events was significantly higher than that of LGE (0.881 vs. 0.768, p = 0.037) and GLS (0.881 vs. 0.747, p = 0.036). CONCLUSIONS: CFR assessed using coronary sinus PC cine CMR may be useful as a non-invasive prognostic marker for HFpEF patients.

DOI： 10.1186/s12968-021-00807-3

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: The purposes of this experimental study were to compare the quantitative and qualitative visibility of in-stent restenosis between conventional-resolution CT (CRCT) and ultra-high-resolution CT (U-HRCT) and to investigate the effects of the image reconstruction techniques on the visualization of in-stent restenosis. MATERIALS AND METHODS: A vessel tube with non-calcified plaque in a 3.0-mm stent was scanned by using CRCT and U-HRCT at 4 stent directions (0, 30, 60, and 90 degrees) to the through-plane direction. Hybrid iterative reconstruction (HIR); model-based iterative reconstruction (MBIR); deep-learning-based reconstruction (DLR) were used as reconstruction methods. The lumen size was assessed using the full width at half maximum method, and image quality was visually evaluated using 4-point scale. RESULTS: U-HRCT had the significantly wider lumen sizes and narrower stent strut thickness than CRCT in three types of the reconstruction methods (P < 0.01). The lumen sizes for U-HRCT with 90 degrees were narrower than those with the other angle directions regardless of the reconstruction methods. Visual score was significantly higher for U-HRCT than CRCT (3.2 ± 0.7 vs 2.0 ± 0.4, P < 0.001). CONCLUSIONS: U-HRCT quantitatively and qualitatively provided better visualization of in-stent restenosis compared to CRCT. Image quality of U-HRCT may be affected by stent angle.

DOI： 10.1007/s11604-021-01200-x

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported as a global emergency. As respiratory dysfunction is a major clinical presentation of COVID-19, chest computed tomography (CT) plays a central role in the diagnosis and management of patients with COVID-19. Recent advances in imaging approaches using artificial intelligence have been essential as a quantification and diagnostic tool to differentiate COVID-19 from other respiratory infectious diseases. Furthermore, cardiovascular involvement in patients with COVID-19 is not negligible and may result in rapid worsening of the disease and sudden death. Cardiac magnetic resonance imaging can accurately depict myocardial involvement in SARS-CoV-2 infection. This review summarizes the role of the radiology department in the management and the diagnosis of COVID-19, with a special emphasis on ultra-high-resolution CT findings, cardiovascular complications and the potential of artificial intelligence.

DOI： 10.1016/j.diii.2021.05.006

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTA0-Tyr3-octreotate (177Lu-DOTATATE) is one of the most reliable treatments for unresectable, progressive neuroendocrine tumors (NETs) with somatostatin receptor expression. We have, for the first time, reported the results of the tolerability, safety, pharmacokinetics, dosimetry, and efficacy of this treatment for Japanese patients with NET. METHODS: Patients with unresectable, somatostatin receptor scintigraphy (SRS)-positive NETs were enrolled in this phase I clinical trial. They were treated with 29.6 GBq of 177Lu-DOTATATE (four doses of 7.4 GBq) combined with amino acid solution infusion plus octreotide long-acting release (LAR) 30 mg. The primary objective of this study was to evaluate the tolerability, safety, pharmacokinetics, and dosimetry of a single administration of this treatment in patients with SRS-positive NETs. RESULTS: Six Japanese patients (three men and three women; mean age 61.5 years; range 50-70 years) with SRS-positive unresectable NETs were recruited. 177Lu-DOTATATE was eliminated from the blood in a two-phase manner. Cumulative urinary excretion of radioactivity was 60.1% (range 49.0%-69.8%) within the initial 6 h. The cumulative renal absorbed dose for 29.6 GBq of 177Lu-DOTATATE was 16.8 Gy (range 12.0-21.2 Gy), and the biological effective dose was 17.0 Gy (range 12.2-21.5 Gy). Administration of 177Lu-DOTATATE was well tolerated, with no dose-limiting toxicities. Grade 3 lymphopenia occurred in two (33.3%) cases, but there were no other severe toxicities. Four patients achieved partial response (objective response rate, 66.7%), one patient had stable disease, and one patient had progressive disease. CONCLUSION: PRRT with 177Lu-DOTATATE was well-tolerated and showed good outcomes in Japanese patients with unresectable NETs. Peptide receptor radionuclide therapy, 177Lu-DOTA0-Tyr3-octreotate .

DOI： 10.1007/s12149-021-01674-9

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/ehjci/jeab055

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Phase-contrast cine cardiovascular magnetic resonance (CMR) of the coronary sinus has emerged as a non-invasive method to measure coronary sinus blood flow (CSBF) and coronary flow reserve (CFR). We aimed to compare the prognostic value of resting CSBF and CFR for predicting major adverse cardiac events (MACE) in patients with known or suspected coronary artery disease (CAD) who underwent vasodilator stress CMR. METHODS: We studied 693 patients with known CAD and 519 patients with suspected CAD admitted to our hospital between 2009 and 2019. The CFR was calculated as the CSBF during adenosine triphosphate infusion divided by CSBF at rest. MACE was defined as composite of cardiovascular death, acute coronary syndrome, heart failure hospitalization, and sustained ventricular tachyarrhythmia. RESULTS: During a median follow-up of 4.6 years, 92 patients (8%) experienced MACE. The resting CSBF was significantly higher in patients with MACE than in patients without MACE (114.7 ± 44.9 mL/min vs. 84.7 ± 30.9 mL/min, p < 0.001 for known CAD; 122.2 ± 33.3 mL/min vs. 86.6 ± 36.7 mL/min, p < 0.001 for suspected CAD). The resting CSBF remained a significant predictor for MACE after adjusting clinical and CMR variables (hazard ratio [HR] of resting CSBF higher than the median: 3.18, p = 0.0083 for known CAD; HR: 23.3, p < 0.001 for suspected CAD). The area under the curve for predicting MACE was 0.73 for resting CSBF, 0.72 for CFR (p = 0.78) in patients with known CAD, and 0.82 for resting CSBF, 0.83 (p = 0.58) for CFR in patients with suspected CAD. CONCLUSIONS: The resting CSBF may be a useful non-invasive method for the risk stratification of patients with known or suspected CAD without any radiation exposure, contrast media, or pharmacological vasodilator agents.

DOI： 10.1186/s12968-021-00790-9

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Absence of myocardial fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is associated with improvement of left ventricular systolic function after catheter ablation (CA) for atrial fibrillation (AF) with non-ischemic dilated cardiomyopathy (NIDCM). Extracellular volume fraction (ECV) by T1 mapping has emerges as a non-invasive mean to quantify severity of myocardial fibrosis. The aim of this study was to assess the incremental value of ECV over LGE-MRI for the improvement of LVEF(∆EF) after CA in NIDCM patients. A total of thirty-two patients with NIDCM and AF (mean age 67.4 ± 9.3 years; 29 (91%) male) were retrospectively studied. Using a 1.5 T MR scanner and 32 channel cardiac coils, LGE-MRI, pre- and post-T1 mapping images of LV wall at mid-ventricular level (modified look-locker inversion recovery sequence) were acquired. All patients successfully underwent CA for AF, and the improvement of LVEF after CA were evaluated by echocardiography. All patients restored sinus rhythm after CA at the time of echocardiography. The mean LVEF was 35.1 ± 9.7% before CA and 52.2 ± 10.2% after CA (p < 0.001), resulting an increase of 17.4 ± 12.6%. Significant correlation was found between ∆LVEF and % LGE (r = - 0.49, p = 0.004), ∆LVEF and extracellular volume fraction (ECV) (r = - 0.47, p = 0.010). Area under the receiver operating characteristics curve (AUC) of combination of %LGE and ECV for predicting improvement of LVEF > 10% was substantially higher than that of %LGE alone (AUC: 0.830 vs 0.602). In NIDCM patients with AF, ECV had incremental value over %LGE for predicting improvement of EF by CA, suggesting that the assessment of diffuse interstitial fibrosis may be important to forecast the response of CA.

DOI： 10.1007/s10554-021-02219-x

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The aim of this study was to investigate the prevalence and prognostic value of coronary artery disease (CAD) and heart failure (HF) in patients with idiopathic pulmonary fibrosis (IPF). Thirteen hundred and fifty-eight patients with interstitial lung disease [851 (62%) males, mean age: 68 ± 10 years] were retrospectively analyzed. CAD was defined as (1) the presence of a clinical diagnosis of angina pectoris, (2) clinical diagnosis of a myocardial infarction, and (3) coronary angiography showing ≥ 1 vessel with a stenosis of > 75%. The definition of HF was made according to the modified Framingham criteria. Compared to the non-IPF group (n = 790), the IPF group (n = 568) had a significantly higher prevalence of CAD (9.3% vs. 4.4%, p < 0.001) and HF (8.2% vs. 3.7%, p < 0.001). During a median follow-up of 1.6 years, 152 deaths were identified. The patients with HF had a significantly worse prognosis than those without HF both in the non-IPF group and IPF group (both p < 0.05). However, the prognosis did not significantly differ between the patients with CAD and those without CAD both in the non-IPF group and IPF group. The presence of HF was an independent predictor of death in the IPF [hazard ratio (HR) 3.67, 95% confidence interval (CI) 1.57-8.56, p = 0.0025] and non-IPF (HR 5.07, 95% CI 1.44-17.86, p = 0.011) patients. The prevalence of CAD and HF was significantly higher in IPF than non-IPF patients. In addition, the presence of HF was a significant prognostic factor for both IPF and non-IPF patients. These results indicated that the importance of HF as a comorbidity for patients with ILD.

DOI： 10.1007/s00380-021-01787-1

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is performed in patients with hemorrhagic shock who develop massive subdiaphragmatic bleeding. This procedure enables rapid and less invasive aortic blockade compared to resuscitative thoracotomy and aortic cross-clamp procedures. However, the REBOA procedure is often blindly performed in the emergency department without fluoroscopy, and the appropriateness of the procedure may be evaluated on computed tomography (CT) after REBOA. Therefore, radiologists should be familiar with the imaging features of REBOA. We present a pictorial review of the radiological findings of REBOA along with a description of the procedure, its complications, and pitfalls.

DOI： 10.1007/s11604-021-01166-w

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Myocardial perfusion and perfusion reserve are diminished in patients with atrial fibrillation (AF). Phase-contrast (PC) cine magnetic resonance imaging (MRI) of the coronary sinus serves as a non-invasive means of quantifying coronary flow reserve (CFR) without any radioactive tracer. The present study aimed to evaluate the utility of PC cine MRI of the coronary sinus for assessing decreased CFR in patients with AF. We studied 362 patients with known or suspected coronary artery disease (CAD) [age 72 ± 9 years; 267 (74%) male; 90 (25%) had AF] and 20 age- and gender-matched control subjects [age 72 ± 9 years, 14 (70%) male]. Using a 1.5-T MR scanner and cardiac coils, blood flow of the coronary sinus (CBF) was quantified by PC cine MRI. CFR was calculated as CBF during adenosine triphosphate infusion divided by CBF at rest. CFR was significantly lower in patients with AF than in those without AF among all patients (n = 362) (2.45 ± 0.42 vs. 2.71 ± 0.58, p < 0.001), in patients with known CAD (n = 155) (2.40 ± 0.46 vs. 2.72 ± 0.58, p = 0.002), and in those with suspected CAD (n = 207) (2.49 ± 0.40 vs. 2.72 ± 0.59, p = 0.007). Significant differences in CFR were found between controls and patients without AF (3.12 ± 0.52 vs. 2.71 ± 0.58, p < 0.001). AF was independently associated with CFR in both known CAD patients [β = - 0.248, 95% confidence interval (CI): - 0.561 to - 0.119, p = 0.003) and suspected CAD patients (β =  - 0.154, 95% CI - 0.353 to - 0.034, p = 0.018). The presence of AF was related to impaired CFR in both known and suspected CAD patients. PC cine MRI of the coronary sinus can be useful for detecting impaired CFR in patients with AF.

DOI： 10.1007/s00380-020-01759-x

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: The role of hepatic iron overload (HIO) in nonalcoholic fatty liver disease (NAFLD) pathogenesis has not been fully elucidated. PURPOSE: This study aimed to investigate the effect of HIO and examine the diagnostic usefulness of magnetic resonance imaging (MRI)-based R2* quantification in evaluating hepatic iron content (HIC) and pathological findings in NAFLD. STUDY TYPE: Prospective and retrospective. POPULATION: A prospective study of 168 patients (age, 57.2 ± 15.0; male/female, 80/88) and a retrospective validation study of 202 patients (age, 57.0 ± 14.4; male/female, 113/89) with liver-biopsy-confirmed NAFLD were performed. FIELD STRENGTH/SEQUENCE: 3 T; chemical-shift encoded multi-echo gradient echo. ASSESSMENT: Using liver tissues obtained by liver biopsy, HIC was prospectively evaluated in 168 patients by atomic absorption spectrometry. Diagnostic accuracies of HIC and R2* for grading hepatic inflammation plus ballooning (HIB) as an indicator of NAFLD activity were assessed. STATISTICAL TESTS: Student's t-test and analysis of variance (ANOVA) with Scheffe's multiple testing correction for univariate comparisons; multivariate logistic analysis. P-value less than 0.05 is statistically significant. RESULTS: HIC was significantly correlated with HIB grades (r = 0.407). R2* was significantly correlated with HIC (r = 0.557) and HIB grades (r = 0.569). R2* mapped an area under the receiver operating characteristic (AUROC; 0.774) for HIC ≥808 ng/mL (median value) with cutoff value of 62.5 s-1 . In addition, R2* mapped AUROC of HIB for grades ≥3 was 0.799 with cutoff value of 58.5 s-1 . When R2* was <62.5 s-1 , R2* correlated weakly with HIC (r = 0.372) as it was affected by fat deposition and did not correlate with HIB grades (P = 0.052). Conversely, when R2* was ≥62.5 s-1 , a significant correlation of R2* with HIC (r = 0.556) and with HIB grades was observed (P < 0.0001) with being less affected by fat deposition. DATA CONCLUSION: R2*  ≥ 62.5 s-1 is a promising modality for non-invasive diagnosis of clinically important high grades (≥3) of HIB associated with increased HIC. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

DOI： 10.1002/jmri.27810

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

ABSTRACT: The Coronavirus disease 2019 pandemic continues to spread worldwide. Because of the absence of reliable rapid diagnostic systems, patients with symptoms of Coronavirus disease 2019 are treated as suspected of the disease. Use of computed tomography findings in Coronavirus disease 2019 are expected to be a reasonable method for triaging patients, and computed tomography-first triage strategies have been proposed. However, clinical evaluation of a computed tomography-first triage protocol is lacking.The aim of this study is to investigate the real-world efficacy and limitations of a computed tomography-first triage strategy in patients with suspected Coronavirus disease 2019.This was a single-center cohort study evaluating outpatients with fever who received medical examination at Yokohama City University Hospital, prospectively registered between 9 February and 5 May 2020. We treated according to the computed tomography-first triage protocol. The primary outcome was efficacy of the computed tomography-first triage protocol for patients with fever in an outpatient clinic. Efficacy of the computed tomography-first triage protocol for outpatients with fever was evaluated using sensitivity, specificity, positive predictive value, and negative predictive value. We conducted additional analyses of the isolation time of feverish outpatients and final diagnoses.In total, 108 consecutive outpatients with fever were examined at our hospital. Using the computed tomography-first triage protocol, 48 (44.9%) patients were classified as suspected Coronavirus disease 2019. Nine patients (18.8%) in this group were positive for severe acute respiratory syndrome coronavirus 2 using polymerase chain reaction; no patients in the group considered less likely to have Coronavirus disease 2019 tested positive for the virus. The protocol significantly shortened the duration of isolation for the not-suspected versus the suspected group (70.5 vs 1037.0 minutes, P < .001).Our computed tomography-first triage protocol was acceptable for screening patients with suspected Coronavirus disease 2019. This protocol will be helpful for appropriate triage, especially in areas where polymerase chain reaction is inadequate.

DOI： 10.1097/MD.0000000000026161

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To assess the relationships among pulmonary vascular enlargement, computed tomography (CT) findings quantified with software, and coronavirus disease (COVID-19) severity. MATERIALS AND METHODS: Ultra-high-resolution (UHR) CT images of 87 patients (50 males, 37 females; median age, 63 years) with COVID-19 confirmed using real-time polymerase chain reaction were analyzed. The maximum subsegmental vascular diameter was measured on CT. Total CT lung volume (CTLV total) and lesion extent (ratio of lesion volume to CTLV total) of ground-glass opacities, reticulation, and consolidation were measured using software. Maximum pulmonary vascular diameter and lesion extent were analyzed using Spearman's correlation analysis. Logistic regression analysis was performed on CT results to predict disease severity. We also assessed changes in these measures on follow-up scans in 16 patients. RESULTS: All 23 patients with severe and critical illness had vascular enlargement (> 4 mm). Pulmonary vascular enlargement (odds ratio 3.05, p = 0.018) and CT lesion extent (odds ratio 1.07, p = 0.002) were independent predictors of disease severity after adjustment for age and comorbidities. On follow-up CT, vascular diameter and CT lesion volume decreased (p = 0.001, p = 0.002; respectively), but CTLV total did not change significantly. CONCLUSION: Subsegmental vascular enlargement is a notable finding to predict acute COVID-19 disease severity.

DOI： 10.1007/s11604-020-01085-2

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective We assessed the effect of canagliflozin, an SGLT2 inhibitor, on hepatic steatosis using three imaging modalities: magnetic resonance imaging (MRI), computed tomography, and transient elastography. We further determined factors associated with improving hepatic steatosis by canagliflozin among patients with type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Methods We conducted a six-month prospective single-arm study between August 2015 and June 2017. The primary outcome was the change in hepatic steatosis assessed using the hepatic proton density fat fraction (PDFF) on MRI before and after treatment with canagliflozin. The secondary outcomes were changes in measures of glucose metabolism, including the hepatic glucose uptake on FDG-PET, and the inflammation and volumes of visceral and subcutaneous adipose tissue and skeletal muscle. Patients Nine patients with type 2 diabetes and NAFLD completed this study. All participants received canagliflozin at a dose of 100 mg daily. Results Canagliflozin caused a significant reduction in hepatic PDFF from baseline (median 20.6% [interquartile range 11.7%, 29.8%]) after 6 months (10.6% [5.4%, 22.6%], p=0.008). Canagliflozin also significantly reduced the body weight, glycated hemoglobin, homeostasis model assessment of insulin resistance (HOMA-IR), high sensitivity C-reactive protein (hs-CRP), and volumes of adipose tissue and skeletal muscle (all p<0.05). The reduction in hepatic PDFF was not correlated with changes in the body weight, HOMA-IR, hs-CRP, or volume of adipose tissue and skeletal muscle from baseline after six months. Conclusion Among patients with type 2 diabetes and NAFLD, canagliflozin improved hepatic steatosis. The effect may be independent of reducing adiposity, insulin resistance, inflammation, and skeletal muscle volume.

DOI： 10.2169/internalmedicine.7134-21

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1161/CIRCIMAGING.120.012177

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: The aims of this study were to investigate the relationship between pulmonary hypertension (PH) and right ventricular (RV) strain, and to evaluate the prognostic value of RV strain by cardiac magnetic resonance (CMR) feature tracking for patients with interstitial lung disease (ILD). METHODS: A total of seventy ILD patients (mean age: 71 ± 8 years, 39 [56%] males) who underwent CMR and right heart catheterization (RHC) were studied. Using a 1.5T magnetic resonance (MR) scanner, steady-state free precession cine MR images encompassing the RV were acquired in all patients and 20 control subjects. RV longitudinal strain were calculated with a feature tracking algorithm. PH was defined as a mean pulmonary artery pressure of more than 20 mmHg at rest and a pulmonary vascular resistance ≥3 Woods unit. RESULTS: The RV longitudinal strain was significantly impaired in the ILD patients with PH (n=18) than ILD patients without PH (n=52) (-13.3 ± 5.4% vs. -16.9±5.4%, p=0.048). The RV longitudinal strain differed significantly between the ILD patients without PH and the controls (n=20) (-16.9 ± 5.4% vs. -20.8 ± 6.2%, p=0.002). Five of 70 (7%) patients died within one-year after CMR scan. Area under receiver operating characteristics curve for predicting death was 0.900 (95%CI: 0.800 to 1.000) for RV strain, 0.643 (95%CI: 0.454 to 0.832) for RVEF. CONCLUSIONS: Presence of PH was associated with impairment of RV strain, and RV strain could predict short-term mortality in patients with ILD. RV strain by feature tracking might be useful as a non-invasive prognostic marker for patients with ILD.

DOI： 10.1007/s10554-020-02079-x

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the effects of deep learning reconstruction (DLR) in qualitative and quantitative image quality of non-contrast magnetic resonance coronary angiography (MRCA). METHODS: Ten healthy volunteers underwent conventional MRCA (C-MRCA) and high-resolution (HR) MRCA on a 3T magnetic resonance imaging with a voxel size of 1.8 × 1.1 × 1.7 mm3 and 1.8 × 0.6 × 1.0 mm3, respectively, for C-MRCA and HR-MRCA. High-resolution magnetic resonance coronary angiography was also reconstructed with the DLR technique (DLR-HR-MRCA). We compared the contrast-to-noise ratio (CNR) and visual evaluation scores for vessel sharpness and traceability of proximal and distal coronary vessels on a 4-point scale among 3 image series. RESULTS: The vascular CNR value on the C-MRCA and the DLR-HR-MRCA was significantly higher than that on the HR-MRCA in the proximal and distal coronary arteries (13.9 ± 6.4, 11.3 ± 4.4, and 7.8 ± 2.6 for C-MRCA, DLR-HR-MRCA, and HR-MRCA, P < .05, respectively). Mean visual evaluation scores for the vessel sharpness and traceability of proximal and distal coronary vessels were significantly higher on the HR-DLR-MRCA than the C-MRCA (P < .05, respectively). CONCLUSION: Deep learning reconstruction significantly improved the CNR of coronary arteries on HR-MRCA, resulting in both higher visual image quality and better vessel traceability compared with C-MRCA.

DOI： 10.1177/0846537119900469

PubMed

researchmap

担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：(一社)日本インターベンショナルラジオロジー学会  

症例は50歳代女性。交通事故により全身多発外傷を受傷し、骨盤骨折に伴う大量出血に対して経カテーテル的動脈塞栓術(TAE)を行う方針となった。造影CTでは、不安定型骨盤骨折が認められ、骨盤骨折の骨片が右内腸骨動脈側へ転位していた。右内腸骨動脈造影では、外側仙骨動脈と子宮動脈が描出されていたが、それより遠位で内腸骨動脈は完全に閉塞していた。術中所見は、塞栓物質としてNBCAを用いて塞栓し、左内腸骨動脈造影で認められた広範な動脈における血管径の不整や狭小化に対し、左内腸骨動脈本幹からゼラチンスポンジ細片を用いて塞栓した。術後、骨盤骨折に対して創外固定術を施行し、術翌日には観血的整復固定術を施行した。固定後は経過良好で、再出血や合併症は認めず、受傷12日後にリハビリ目的に他院転院となった。

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Cancers of unknown primary origin cannot be staged using images, making the prognosis difficult. We attempted to predict prognosis of patients with unknown primary origin using tumour heterogeneity recently introduced in F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT). METHODS: Overall, 30 patients with unknown primary origin who underwent whole-body F-FDG PET/CT scans were retrospectively enrolled for texture analysis. The volume of interest was placed in the largest metastatic lymph nodes and conventional parameters and grey-level co-occurrence matrix (GLCM) were calculated. Statistical analysis of image-based variables was performed using Cox regression analyses. Patients were stratified into two groups based on cutoff values of GLCMentropy obtained using receiver operating characteristics (ROCs). Patients were analyzed, and overall survival (OS) was compared using Kaplan-Meier analysis. RESULTS: Univariate Cox regression analysis showed significant differences in prognosis for parenchymal organ metastasis (P < 0.01), GLCM homogeneity (P = 0.01), GLCMcontrast (P < 0.01), GLCMentropy (P < 0.01) and GLCMdissimilarity (P < 0.01). Multivariate Cox regression analysis showed a significant difference in reduced prognosis for GLCMentropy positive (P < 0.01). Stratification was performed based on the GLCMentropy cutoff value, determined using ROCs analysis, with smaller groups showing better OS. CONCLUSIONS: Despite previous difficulties in predicting prognosis in patients with unknown primary origin, F-FDG PET/CT texture features may enable stratification of prognosis. This could be useful for appropriate patient selection and management and help identify a subset of patients with favourable outcomes. These novel findings may be helpful for prognostication and improving patient care.

DOI： 10.1097/MNM.0000000000001310

PubMed

researchmap

担当区分：最終著者   記述言語：英語  

In high-speed motor vehicle accidents, it is necessary to investigate the manner of death. Postmortem computed tomography (PMCT) provides important information on the mechanism of death, but identification of the aortic injury is still challenging on non-contrast PMCT. A man in his 50s had multiple injuries on the face and chest in the high-speed motor vehicle accident. The traumatic aortic rupture was clearly depicted on thin-slice and multiplanar reformation PMCT images. Traumatic aortic disruption was confirmed by forensic autopsy. The high contrast between the aortic wall and the lumen visualized the traumatic rupture in the distal aortic arch. For the evaluation of aortic rupture on PMCT, it may be important to trace the continuity of the high-density aortic wall by reviewing thin-slice CT and multiplanar reformation images.

DOI： 10.1016/j.radcr.2020.10.029

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1177/0284185120902393

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVES: Fractional flow reserve (FFR) is an established technique for detecting lesion-specific ischemia but is invasive. Our objective was to investigate the effects of combined assessment of coronary CT angiography (CCTA) imaging features and CT-FFR on detecting lesion-specific ischemia by comparing with invasive FFR. MATERIALS AND METHODS: Forty-seven patients who had 60 coronary vessels with 30%-90% stenosis were included. Six anatomic CCTA descriptors (Agatston score, stenosis severity, mean plaque CT attenuation value, noncalcified and calcified plaque volumes, remodeling index) and a functional descriptor (CT-FFR) were measured. Random forest was used to identify which descriptors were useful to identify ischemia-related lesion. Receiver-operating characteristic (ROC) curves were calculated for 2 models: i.e. Model-1 for anatomical CT descriptors and Model-2 for anatomical CT descriptors plus CT-FFR. RESULTS: Stenosis severity (40.8 ± 15.7% vs 57.6 ± 14.1%), noncalcified plaque volume (190 ± 100 vs 254.8 ± 133.3), and remodeling index (1.04 ± 0.12 vs 1.11 ± 0.13) were significantly higher in ischemia-related lesions than nonischemia-related lesions. CT-FFR was 0.84 ± 0.14 and 0.71 ± 0.14, respectively, for ischemia-related and nonischemia-related lesions, and the difference was significant. The area under the ROC curve was 0.738 and 0.835 in Model-1 and Model-2, respectively. Reclassification of ischemic lesion risk was significantly improved after adding CT-FFR: net reclassification improvement was 0.297 and integrated discrimination improvement was 0.254. CONCLUSION: Combined assessment of anatomical CCTA features and functional CT-FFR was helpful for detecting lesion-specific ischemia.

DOI： 10.1016/j.acra.2019.12.013

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND & AIMS: As alternatives to the expensive liver biopsy for assessing liver fibrosis stage in patients with nonalcoholic fatty liver disease (NAFLD), we directly compared the diagnostic abilities of magnetic resonance elastography (MRE), vibration-controlled transient elastography (VCTE), and two-dimensional shear wave elastography (2D-SWE). METHODS: Overall, 231 patients with biopsy-proven NAFLD were included. Intra- and inter-observer reproducibility was analyzed using intraclass correlation coefficient in a sub-group of 70 participants, in whom liver stiffness measurement (LSM) was performed by an elastography expert and an ultrasound expert who was an elastography trainee on the same day. RESULTS: Valid LSMs were obtained for 227, 220, 204, and 201 patients using MRE, VCTE, 2D-SWE, and all three modalities combined, respectively. Although the area under the curve did not differ between the modalities for detecting stage >1, >2, and >3 liver fibrosis, it was higher for MRE than VCTE and 2D-SWE for stage 4. Sex was a significant predictor of discordance between VCTE and liver fibrosis stage. Skin-capsule distance and the ratio of the interquartile range of liver stiffness to the median were significantly associated with discordance between 2D-SWE and liver fibrosis stage. However, no factors were associated with discordance between MRE and liver fibrosis stage. Intra- and inter-observer reproducibility in detecting liver fibrosis was higher for MRE than VCTE and 2D-SWE. CONCLUSIONS: MRE, VCTE, and 2D-SWE demonstrated excellent diagnostic accuracy in detecting liver fibrosis in patients with NAFLD. MRE demonstrated the highest diagnostic accuracy for stage 4 detection and intra- and inter-observer reproducibility. UMIN Clinical Trials Registry No. UMIN000031491.

DOI： 10.1016/j.cgh.2020.12.016

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: To compare the estimated radiation dose of 50% reduced iodine contrast medium (halfCM) for virtual monochromatic images (VMIs) with that of standard CM (stdCM) with a 120 kVp imaging protocol for contrast-enhanced CT (CECT). Methods: We enrolled 30 adults with renal dysfunction who underwent abdominal CT with halfCM for spectral CT. As controls, 30 matched patients without renal dysfunction using stdCM were also enrolled. CT images were reconstructed with the VMIs at 55 keV with halfCM and 120 kVp images with stdCM and halfCM. The Monte-Carlo simulation tool was used to simulate the radiation dose. The organ doses were normalized to CTDIvol for the liver, pancreas, spleen, and kidneys and measured between halfCM and stdCM protocols. Results: For the arterial phase, the mean organ doses normalized to CTDIvol for stdCM and halfCM were 1.22 and 1.29 for the liver, 1.50 and 1.35 for the spleen, 1.75 and 1.51 for the pancreas, and 1.89 and 1.53 for the kidneys. As compared with non-enhanced CT, the average increase in the organ dose was significantly lower for halfCM (13.8% ± 14.3 and 26.7% ± 16.7) than for stdCM (31.0% ± 14.3 and 38.5% ± 14.8) during the hepatic arterial and portal venous phases (p < 0.01). Conclusion: As compared with stdCM with the 120 kVp imaging protocol, a 50% reduction in CM with VMIs with the 55 keV protocol allowed for a substantial reduction of the average organ dose of iodine CM while maintaining the iodine CT number for CECT. Advances in knowledge: This study provides that the halfCM protocol for abdominal CT with a dual-layer-dual-energy CT can significantly reduce the increase in the average organ dose for non-enhanced CT as compared with the standard CM protocol.

DOI： 10.1259/bjro.20200006

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

We aimed to investigate the correlation of graft flow measurements between transit-time flow measurement (TTFM) during coronary artery bypass grafting (CABG) surgery and dynamic cardiac CT after the surgery.Fourteen patients underwent CABG with TTFM and postoperative dynamic cardiac CT; 11 internal thoracic artery (ITA) grafts and 15 saphenous venous grafts (SVGs) were included for analysis. Pearsons correlation analysis was performed for the comparisons of the TTFM and cardiac dynamic CT flow parameters.TTFM was not significantly correlated with the CT flow of the ITA grafts (r = -0.23, P = .49), but it had a very strong correlation with the CT flow of the SVGs (r = 0.83, P < .01).In patients who underwent CABG surgery, dynamic cardiac CT enabled quantitative evaluation of SVG flow, with good correlation with TTFM.

DOI： 10.1097/MD.0000000000023338

PubMed

researchmap

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Although non-invasive assessment of coronary flow reserve (CFR) by cardiovascular magnetic resonance (CMR) provides prognostic information for patients with diabetes mellitus (DM), the incremental prognostic value of CMR-derived CFR remains unclear. PURPOSE: To evaluate the incremental prognostic value of CMR-derived CFR for patients with DM who underwent stress CMR imaging. MATERIALS AND METHODS: A total of 309 patients with type 2 DM [69 ± 9 years; 244 (78%) male] assessed between 2009 and 2019 were retrospectively reviewed. Coronary sinus blood flow (CSBF) was measured using phase contrast (PC) cine CMR. CFR was calculated as the CSBF during adenosine triphosphate infusion divided by that at rest. Major adverse cardiac events (MACE) were defined as death, acute coronary syndrome, hospitalization due to heart failure exacerbation, or sustained ventricular tachycardia. The incremental prognostic value of CFR over clinical and CMR variables was assessed by calculating the C-index and net reclassification improvement (NRI). RESULTS: During a median follow-up of 3.8 years, 42 patients (14%) experienced MACE. The annualized event rate was significantly higher among patients with CFR < 2.0, regardless of the presence of late gadolinium enhancement (LGE) (1.4% vs. 9.8%, p = 0.011 in the LGE (-) group; 1.8% vs. 16.9%, p < 0.001 in the LGE (+) group). In addition, this trend was maintained in the subgroups stratified by presence or absence of ischemia (0.3% vs. 6.7%, p = 0.007 in the ischemia (-) group; 3.9% vs. 17.1%, p = 0.001 in the ischemia (+) group). Adding CFR to the risk model (age + gender + left ventricular ejection fraction + %LGE + %ischemia) resulted in a significant increase of the C-index from 0.838 to 0.870 (p = 0.038) and an NRI of 0.201 (0.004-0.368, p = 0.012). CONCLUSION: PC cine CMR-derived CFR of the coronary sinus may be useful as a prognostic marker for DM patients, incremental to common clinical and CMR parameters. Due to the high prevalence of coronary microvascular dysfunction, the addition of CFR to conventional vasodilator stress CMR imaging may improve risk stratification for patients with DM.

DOI： 10.1186/s12968-020-00667-3

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The extracellular volume fraction (ECV) by T1 mapping can quantify diffuse myocardial fibrosis, and useful as a non-invasive marker for risk stratification for patients with non-ischemic dilated cardiomyopathy (NIDCM). Prolonged QRS interval on electrocardiogram is related to worse clinical outcome for heart failure patients. The purpose of this study was to evaluate the prognostic value of the combination of ECV and QRS duration for NIDCM patients. A total of 60 NIDCM patients (mean age 61 ± 12 years, mean left ventricular ejection fraction 37 ± 10%, mean QRS duration 110 ± 19 ms) were enrolled. Using a 1.5-T MR scanner and 32-channel cardiac coils, the mean ECV value of six myocardial segments at the mid-ventricular level was measured by the modified look-locker inversion recovery method. Adverse events were defined as follows: cardiac death; recurrent hospitalization due to heart failure. Patients were allocated into three groups based on ECV value and QRS duration (group 1: ECV ≦ 0.30 and QRS ≦ 120 ms; group 2: ECV > 0.30 or QRS > 120 ms; group 3: ECV > 0.30 and QRS > 120 ms). During a median follow-up duration of 370 days, 7 of 60 (12%) NIDCM patients experienced adverse events. NIDCM patients with events had longer QRS duration (134 ± 31 ms vs. 106 ± 14 ms, p = 0.01) and higher ECV (0.34 ± 0.07 vs 0.29 ± 0.05, p = 0.026) compared with those without events. On Kaplan-Meier curve analysis, significant difference was found between group 1 and group 3 (p < 0.001, log-rank test). No significant difference was found between group 1 and group 2 (p = 0.053), group 2 and group 3 (p = 0.115). The area under the receiver operating characteristic curve (AUC) for predicting adverse events was 0.778 (95% confidence interval CI 0.612-0.939) for ECV, 0.792 (95% CI 0.539-0.924) for QRS duration, 0.822 (95% CI 0.688-0.966) for combination of ECV and QRS duration. NIDCM patients with high ECV and prolonged QRS duration had significantly worse prognosis compared to those with normal ECV and normal QRS duration. The combination of ECV and QRS duration could be useful as a non-invasive method for better risk stratification for patients with NIDCM.

DOI： 10.1007/s00380-020-01618-9

PubMed

researchmap

記述言語：日本語   出版者・発行元：(公社)日本医学放射線学会  

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We examined whether water-hydroxyapatite (HAP) images improve the diagnostic accuracy of bone metastasis compared with non-contrast CT alone. We retrospectively evaluated dual-energy computed tomography (DECT) images of 83 cancer patients (bone metastasis, 31; without bone metastasis, 52) from May 2018 to June 2019. Initially, two evaluators examined for bone metastasis on conventional CT images. In the second session, both CT and CT images plus water-HAP images on DECT. The confidence of bone metastasis was scored from 1 (benign) to 5 (malignant). The sensitivity, specificity, positive predictive values, and negative predictive values for both modalities were calculated based on true positive and negative findings. The intra-observer area under curve (AUC) for detecting bone metastasis was compared by receiver operating characteristic analysis. Kappa coefficient calculated the inter-observer agreement. In conventional CT images, sensitivity, specificity, positive predictive value, and negative predictive value of raters 1 and 2 for the identification of bone metastases were 0.742 and 0.710, 0.981 and 0.981, 0.958 and 0.957, and 0.864 and 0.850, respectively. In water-HAP, they were 1.00 and 1.00, 0.981 and 1.00, 0.969 and 1.00, and 1.00 and 1.00, respectively. In CT, AUCs were 0.861 and 0.845 in each observer. On water-HAP images, AUCs were 0.990 and 1.00. Kappa coefficient was 0.964 for CT and 0.976 for water-HAP images. The combination of CT and water-HAP images significantly increased diagnostic accuracy for detecting bone metastasis. Water-HAP images on DECT may enable accurate initial staging, reduced radiation exposure, and cost.

DOI： 10.3390/diagnostics10100853

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Feature tracking (FT) has emerged as a promising method to quantify myocardial strain using conventional cine magnetic resonance imaging (MRI). Extracellular volume fraction (ECV) by T1 mapping enables quantification of myocardial fibrosis. To date, the correlation between FT-derived left ventricular strain and ECV has not been elucidated yet. The aim of this study was to evaluate the relationship between myocardial strain by FT and ECV by T1 mapping in patients with non-ischemic dilated cardiomyopathy (NIDCM). METHODS: A total of 57 patients with NIDCM (61 ± 12 years; 46 (81%) male)) and 15 controls (62 ± 11 years; 11 (73%) male)) were studied. Using a 1.5 T magnetic resonance scanner, pre- and post- T1 mapping images of the LV wall at the mid-ventricular level were acquired to calculate the ECV by a modified Look-Locker inversion recovery (MOLLI) sequence. The radial strain (RS), circumferential strain (CS), and longitudinal strain (LS) were assessed by the FT technique. The ECV and myocardial strain were compared using a 6-segment model at the mid-ventricular level. RESULTS: The ECV and myocardial strain were evaluable in all 432 segments in 72 subjects. On a patient-based analysis, NIDCM patients had a significantly higher ECV (0.30 ± 0.07 vs. 0.28 ± 0.06, p = .007) and impaired myocardial strain than the control subjects (RS, 22.7 ± 10.3 vs. 30.3 ± 18.2, p < .01; CS, -6.47 ± 1.89 vs. -9.52 ± 5.15, p < .001; LS -10.2 ± 3.78 vs. -19.8 ± 4.30, p < .001, respectively). A significant linear correlation was found between the RS and ECV (r = -0.38, p < .001) and CS and ECV, (r = 0.38, p < .001). LS and ECV also correlated (r = 0.31, p < 0.001). On a segment-based analysis, there was a significant correlation between the ECV and RS and ECV and CS (all p values < .05). The intraclass correlation coefficient was good for the strain measurement (>0.80). CONCLUSIONS: In patients with NIDCM, significant correlation was found between myocardial strain and ECV, suggesting the FT-derived myocardial strain might be useful as a non-invasive imaging marker for the detection of myocardial fibrosis without any contrast media.

DOI： 10.1016/j.mri.2020.09.004

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We present a case of a 14-year old boy with tumor-associated refractory epilepsy. Positron emission tomography imaging demonstrated a region with heterogeneous high 11C-methionine uptake and a region with homogenous low 18F-fluorodeoxyglucose uptake within the tumor. Histopathological and genomic analyses confirmed the tumor as BRAF V600E-mutated polymorphous low-grade neuroepithelial tumor of the young (PLNTY). Within the high-methionine-uptake region, we observed increased protein levels of L-type amino acid transporter 1 (LAT1), a major transporter of methionine; c-Myc; and constituents of the mitogen-activated protein kinase (MAPK) pathway. We also found that LAT1 expression was linked to the BRAF V600E mutation and subsequent activation of MAPK signaling and c-Myc. Pharmacological and genetic inhibition of the MAPK pathway suppressed c-Myc and LAT1 expression in BRAF V600E-mutated PLNTY and glioblastoma cells. The BRAF inhibitor dabrafenib moderately suppressed cell viability in PLNTY. Collectively, our results indicate that BRAF V600E mutation-activated MAPK signaling and downstream c-Myc induces specific metabolic alterations in PLNTY, and may represent an attractive target in the treatment of the disease.

DOI： 10.1186/s40478-020-01023-3

PubMed

researchmap

記述言語：英語  

Peliosis hepatis involves multiple blood-filled cystic spaces in the hepatic parenchyma. Using conventional imaging, distinguishing PH from other malignancies can be difficult. The findings of Peliosis hepatis on gadoxetic acid (Gd-EOB) enhanced magnetic resonance imaging are not well reported. Therefore, we report the imaging features of pathologically proven PH. On the hepatobiliary phase of Gd-EOB magnetic resonance imaging, most lesions showed unenhanced areas, but some lesions showed central enhancement "halo sign."

DOI： 10.1016/j.radcr.2020.04.059

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Although pressure equalization of the sensor-tipped guidewire and systemic pressure is mandatory in measuring fractional flow reserve (FFR), pressure in the distal artery (Pd) with wire advancement can be influenced by hydrostatic pressure related to the height difference between the catheter tip and the distal pressure sensor. We therefore analyzed the impact of hydrostatic pressure on FFR in vivo by modification of the height difference. METHODS: To reveal the anatomical height difference in human coronary arteries, measurement was performed during computed tomography angiography (CTA) of five consecutive patients. Utilizing the healthy coronary arteries of female swine, height difference diversity was reproduced by body rotation and vertical inclination. FFR measurements were performed during maximum hyperemia with adenosine. The height difference was calculated fluoroscopically with a contrast medium-filled balloon for reference. RESULTS: In human coronary CTA, height averages from the ostium in the left anterior descending artery (34.6 mm) were significantly higher than in the left circumflex (-15.5 mm, p = 0.008) and right coronary arteries (-2.3 mm, p = 0.008). In our swine model, reproduced height variation ranged from -7.2 cm to +6.5 cm. Mean FFR was significantly lower in positive sensor height and higher in negative sensor height compared to the reference height. Linear regression analyses revealed significant correlations between height difference and FFR, observed among all coronary arteries, as well as between the height difference and Pd-aortic pressure mismatch. Subtracting 0.622 mmHg/cm height difference from Pd could correct the expected hydrostatic pressure influence. CONCLUSION: Hydrostatic pressure variation resulting from sensor height influenced FFR values might affect interpretation during FFR assessment.

DOI： 10.1016/j.jjcc.2020.01.009

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer  

In the original publication, caption b of Figure 3 has been incorrectly published as: b. Coronal image shows linear opacity in the right lower lobe. The correct caption is given below: b. Coronal image shows linear opacity in the left lower lobe.

DOI： 10.1007/s11604-020-00977-7

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.acra.2019.07.016

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To review the chest computed tomography (CT) findings on the ultra-high-resolution CT (U-HRCT) in patients with the Novel coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: In February 2020, six consecutive patients with COVID-19 pneumonia (median age, 69 years) underwent U-HR CT imaging. U-HR-CT has a larger matrix size of 1024 × 1024 thinner slice thickness of 0.25 mm and can demonstrate terminal bronchioles in the normal lungs; as a result, Reid's secondary lobules and their abnormalities can be identified. The distribution and hallmarks (ground-glass opacity, consolidation with or without architectural distortion, linear opacity, crazy paving) of the lung opacities on U-HRCT were visually evaluated on a 1 K monitor by two experienced reviewers. The CT lung volume was measured, and the ratio of the measured lung volume to the predicted total lung capacity (predTLC) based on sex, age and height was calculated. RESULTS: All cases showed crazy paving pattern in U-HRCT. In these lesions, the secondary lobules were smaller than those in the un-affected lungs. CT lung volume decreased in two cases comparing predTLC. CONCLUSION: U-HRCT can evaluate not only the distribution and hallmarks of COVID-19 pneumonia but also visualize local lung volume loss.

DOI： 10.1007/s11604-020-00956-y

PubMed

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

A novel coronavirus (severe acute respiratory syndrome coronavirus 2) causes a cluster of pneumonia cases in Wuhan, China. It spread rapidly and globally. CT imaging is helpful for the evaluation of the novel coronavirus disease 2019 (COVID-19) pneumonia. Infection control inside the CT suites is also important to prevent hospital-related transmission of COVID-19. We present our experience with infection control protocol for COVID-19 inside the CT suites.

DOI： 10.1007/s11604-020-00948-y

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11604-019-00906-3

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NLM (Medline)  

OBJECTIVE: The purpose of this study was to determine whether computed tomography (CT) angiography with machine learning (ML) can be used to predict the rapid growth of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: This retrospective study was approved by our institutional review board. Fifty consecutive patients (45 men, 5 women, 73.5 years) with small AAA (38.5 ± 6.2 mm) had undergone CT angiography. To be included, patients required at least 2 CT scans a minimum of 6 months apart. Abdominal aortic aneurysm growth, estimated by change per year, was compared between patients with baseline infrarenal aortic minor axis. For each axial image, major axis of AAA, minor axis of AAA, major axis of lumen without intraluminal thrombi (ILT), minor axis of lumen without ILT, AAA area, lumen area without ILT, ILT area, maximum ILT area, and maximum ILT thickness were measured. We developed a prediction model using an ML method (to predict expansion &gt
4 mm/y) and calculated the area under the receiver operating characteristic curve of this model via 10-fold cross-validation. RESULTS: The median aneurysm expansion was 3.0 mm/y. Major axis of AAA and AAA area correlated significantly with future AAA expansion (r = 0.472, 0.416 all P &lt
0.01). Machine learning and major axis of AAA were a strong predictor of significant AAA expansion (&gt
4 mm/y) (area under the receiver operating characteristic curve were 0.86 and 0.78). CONCLUSIONS: Machine learning is an effective method for the prediction of expansion risk of AAA. Abdominal aortic aneurysm area and major axis of AAA are the important factors to reflect AAA expansion.

DOI： 10.1097/RCT.0000000000000958

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objective This study aimed to evaluate virtual monochromatic images (VMIs) obtained using dual-layer dual-energy computed tomography (CT) for breast carcinoma. Methods We retrospectively enrolled 28 patients with breast cancer who were pathologically diagnosed using dual-layer dual-energy CT. Virtual monochromatic images (40-200 keV) were generated. We compared CT number, image noise, contrast, and contrast-to-noise ratio (CNR) between VMIs with the highest CNR and conventional CT images. We performed qualitative image analysis between VMIs at optimized energy and conventional CT images. Results Image noise of VMIs was not significantly different from that of the conventional CT images. As the x-ray energy decreased, CNR increased. The 40-keV VMIs were highest CNR and higher than that of the conventional CT images. In qualitative image analysis, the 40-keV images were significantly higher than conventional CT images. Conclusion Both qualitative and quantitative analyses showed that the image quality of VMIs at 40 keV was significantly higher than that of conventional CT images.

DOI： 10.1097/RCT.0000000000000970

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-019-06337-y

Scopus

PubMed

researchmap

記述言語：英語  

DOI： 10.1016/j.jcmg.2019.07.010

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Since pancreatic steatosis is reported as a possible risk factor for pancreatic cancer, the development of a non-invasive method to quantify pancreatic steatosis is needed. Proton density fat fraction (PDFF) measurement is a magnetic resonance imaging (MRI) based method for quantitatively assessing the steatosis of a region of interest (ROI). Although it is commonly used for quantification of hepatic steatosis, pancreatic PDFF can greatly vary depending on the ROI's location because of the patchy nature of pancreatic fat accumulation. In this study, we attempted to quantify pancreatic steatosis by fat-water MRI with improved reproducibility. METHODS: Using the MRI images of 159 patients with nonalcoholic fatty liver disease, we attempted to calculate the average PDFF of whole pancreas. We set ROIs covering the entire area of the pancreas appearing in every slice and calculated the average PDFF from all the voxels included in the pancreas. We named this average value as whole-pancreatic PDFF and evaluated the reproducibility of the measured values. In addition to whole-pancreatic PDFF, we measured the average PDFF of the pancreatic head (head-PDFF) and that of the pancreatic body plus tail separately and analyzed their correlation with the clinical characteristics of the patients. RESULTS: The mean inter-examiner coefficient of variation of the whole-pancreatic PDFF was 11.39%. The whole-pancreatic PDFF was correlated with age (p = 0.039), body mass index (p = 0.0093) and presence/absence of diabetes (p = 0.0055). The serum level of low-density lipoprotein cholesterol was inversely correlated with the head-PDFF. CONCLUSION: We developed a new measurement method of the pancreatic PDFF with greater reproducibility. Using this method, we characterized pancreatic steatosis in detail. This novel measurement method allows accurate estimation of the severity of pancreatic steatosis and is therefore useful for the detailed characterization of pancreatic steatosis.

DOI： 10.1371/journal.pone.0224921

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVES: Delayed-phase acquisition of the computed tomography (CT) angiography is important for the evaluation of type II endoleaks after endovascular aortic aneurysm repair because the endoleak cavity area is associated with aneurysm sac expansion. Contrast enhancement boost (CE-boost) is a postprocessing technique for increasing the degree of contrast enhancement on contrast-enhanced CT. We aimed to investigate the usefulness of the CE-boost technique for the visualization of type II endoleaks. MATERIALS AND METHODS: This retrospective study included 28 patients with type II endoleaks after endovascular aortic aneurysm repair who underwent triphasic contrast-enhanced CT. Objective (CT number, signal-to-noise ratio, and contrast-to-noise ratio) and subjective quality analyses using a four-point scale (1, poor; 4, excellent) were performed for the conventional early- and delayed-phase images as well as CE-boost delayed-phase images. RESULTS: The CE-boost delayed-phase images yielded a significantly higher CT number (134.5 ± 41.7 HU), signal-to-noise ratio (23.4 ± 10.5), and contrast-to-noise ratio (15.3 ± 8.4) and showed a significantly larger endoleak area (145.0 ± 134.8 mm2) than did the conventional early-phase (95.6 ± 53.2 HU, 7.3 ± 4.7, 4.0 ± 4.2, and 56.2 ± 99.3 mm2, respectively) and delayed-phase (110.5 ± 33.3 HU, 8.2 ± 2.7, 4.9 ± 2.0, and 124.8 ± 131.9 mm2, respectively) images (p < 0.01). The endoleak visibility score was highest for the CE-boost delayed-phase images (2.0 ± 1.0, 3.0 ± 0.6, and 3.4 ± 0.7 for conventional early-phase, delayed-phase, and delayed-phase CE-boost images, respectively; p < 0.001). CONCLUSION: The CE-boost technique facilitates clear visualization of type II endoleak cavities.

DOI： 10.1016/j.acra.2019.01.009

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVE: Uterine leiomyomas with high signal intensity on T2-weighted imaging (T2WI) can be difficult to distinguish from sarcomas. This study assessed the feasibility of using machine learning to differentiate uterine sarcomas from leiomyomas with high signal intensity on T2WI on multiparametric magnetic resonance imaging. MATERIALS AND METHODS: This retrospective study included 80 patients (50 with benign leiomyoma and 30 with uterine sarcoma) who underwent pelvic 3 T magnetic resonance imaging examination for the evaluation of uterine myometrial smooth muscle masses with high signal intensity on T2WI. We used six machine learning techniques to develop prediction models based on 12 texture parameters on T1WI and T2WI, apparent diffusion coefficient maps, and contrast-enhanced T1WI, as well as tumor size and age. We calculated the areas under the curve (AUCs) using receiver-operating characteristic analysis for each model by 10-fold cross-validation and compared these to those for two board-certified radiologists. RESULTS: The eXtreme Gradient Boosting model gave the highest AUC (0.93), followed by the random forest, support vector machine, multilayer perceptron, k-nearest neighbors, and logistic regression models. Age was the most important factor for differentiation (leiomyoma 44.9 ± 11.1 years; sarcoma 58.9 ± 14.7 years; p < 0.001). The AUC for the eXtreme Gradient Boosting was significantly higher than those for both radiologists (0.93 vs 0.80 and 0.68, p = 0.03 and p < 0.001, respectively). CONCLUSION: Machine learning outperformed experienced radiologists in the differentiation of uterine sarcomas from leiomyomas with high signal intensity on T2WI.

DOI： 10.1016/j.acra.2018.11.014

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To investigate whether epicardial fat volume (EFV) quantified on ECG-nongated noncontrast CT (nongated-NCCT) could be used as a reliable and reproducible predictor for coronary artery disease (CAD). METHODS: One hundred seventeen subjects (65 men, mean age 66.6 ± 11.9 years) underwent coronary CT angiography (CCTA) and nongated-NCCT during a single session because of symptoms suggestive of CAD. Two observers independently quantified EFV on both images. Correlation between CCTA-EFV and nongated-NCCT-EFV was assessed using Pearson's correlation coefficient and Bland-Altman plots. Inter-observer agreement was analyzed using concordance correlation coefficients (CCC). Coronary risk factors including EFV were compared between CAD-positive (> 50% stenosis) and CAD-negative groups. The association between EFV and CAD was analyzed using multivariate logistic regression. ROC analysis was performed, and AUC was compared with DeLong's method. RESULTS: Seventy-four subjects were diagnosed with CAD. An excellent correlation was noted between CCTA-EFV and nongated-NCCT-EFV (r = 0.948, p < 0.001), despite the systematic difference between both measurements (mean bias, 1.26). Inter-observer agreement was nearly perfect (CCC, 0.988 and 0.985 for CCTA and nongated-NCCT, respectively, p < 0.001). Significant differences were noted between subjects with versus without CAD in age, hypertension, and EFV on both types of images (p ≤ 0.026). Multivariate analysis revealed that increased EFV on CCTA (odds ratio 1.185, p = 0.003) and nongated-NCCT (odds ratio 1.20, p = 0.015) was independently associated with CAD. There was no significant difference between CCTA-EFV and nongated-NCCT-EFV in AUC for the prediction of CAD (0.659 vs 0.665, p = 0.706). CONCLUSIONS: Despite the absence of ECG gating, EFV measured on NCCT may serve as a reproducible predictor for CAD with accuracy equivalent to EFV measured on CCTA. KEY POINTS: • Despite the absence of ECG gating, the EFV on NCCT provides nearly perfect inter-observer reproducibility and shows excellent correlation with measurements on gated CCTA. • EFV on nongated-NCCT may serve as an independent biomarker for predicting coronary artery disease with accuracy equivalent to that of EFV on gated CCTA.

DOI： 10.1007/s00330-019-06079-x

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: A recent study revealed a high prevalence of transthyretin (TTR) cardiac amyloidosis (CA) in elderly patients. 99 mTc-labeled pyrophosphate (99 mTc-PYP) scintigraphy is a remarkably sensitive and specific modality for TTR-CA, but is only available in specialist centres; thus, it is important to raise the pretest probability. The aim of this study was to evaluate the characteristics of patients with 99 mTc-PYP positivity and make recommendations about patient selection for 99 mTc-PYP scintigraphy.Methods and Results:We examined 181 consecutive patients aged ≥70 years who underwent 99 mTc-PYP scintigraphy at Kumamoto University Hospital between January 2012 and December 2018. Logistic regression analyses showed that high-sensitivity cardiac troponin T (hs-cTnT) ≥0.0308 ng/mL, left ventricular posterior wall thickness ≥13.6 mm, and wide QRS (QRS ≥120 ms) were strongly associated with 99 mTc-PYP positivity. We developed a new index for predicting 99 mTc-PYP positivity by adding 1 point for each of the 3 factors. The 99 mTc-PYP positive rate increased by a factor of 4.57 for each 1-point increase (P<0.001). Zero points corresponded to a negative predictive value of 87% and 3 points corresponded to a positive predictive value of 96% for 99 mTc-PYP positivity. CONCLUSIONS: The combination of biochemical (hs-cTnT), physiological (wide QRS), and structural (left ventricular posterior wall thickness) findings can raise the pretest probability for 99 mTc-PYP scintigraphy. It can assist clinicians in determining management strategies for elderly patients with suspected CA.

DOI： 10.1253/circj.CJ-19-0255

PubMed

researchmap

記述言語：英語  

DOI： 10.1080/13506129.2019.1597701

PubMed

researchmap

記述言語：英語  

DOI： 10.1253/circj.CJ-18-1062

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To evaluate the image quality of virtual-monoenergetic-imaging (VMI) from dual-layer dual-energy CT (DLCT) for the assessment of hypovascular liver metastases and its effect on lesion detectability. METHODS: Eighty-one patients with hypovascular-liver-metastases undergoing portal-venous-phase abdominal DLCT were included. Polyenergetic-images (PEI) and VMI at 40-200 keV (VMI40-200, 10-keV interval) were reconstructed. Image noise, tumor-to-liver contrast, and contrast-to-noise ratio (CNR) of hepatic parenchyma and metastatic nodules (n = 288) were measured to determine the optimal monoenergetic levels. Two radiologists independently and subjectively assessed the image quality (image contrast, image noise, and diagnostic confidence) of PEI and optimal VMI on 5-point scales to determine the best energy. For 38 patients having up to 10 metastases each with diameters < 25 mm (153 lesions), we compared blindly assessed lesion detectability and conspicuity between PEI and VMI at the best energy. RESULTS: Image noise of VMI40-200 was consistently lower than that of PEI (p < 0.01). Tumor-to-liver contrast and CNR increased as the energy decreased with CNR at VMI40-70 being higher than that observed on PEI (p < 0.01). The highest subjective score for diagnostic confidence was assigned at VMI40 followed by VMI50-70, all of which were significantly better than that of PEI (p < 0.01, kappa = 0.75). Lesion detectability at VMI40 was significantly superior to PEI, especially for lesions with diameters of < 10 mm (p < 0.01, kappa ≥ 0.6). CONCLUSIONS: VMI40-70 provided a better subjective and objective image quality for the evaluation of hypovascular liver metastases, and the lesion detectability was improved with use of VMI40 compared with conventional PEI. KEY POINTS: • DLCT-VMI at 40-70 keV provides a superior subjective and objective image quality compared with conventional PEI for the assessment of hypovascular hepatic metastases during portal venous phase. • Tumor-to-liver contrast and CNR of hypovascular hepatic metastases was maximized at 40 keV without a relevant increase in the image noise. • VMI at 40 keV yields a superior lesion detectability, especially for small (< 1 cm) metastatic nodules compared with conventional PEI.

DOI： 10.1007/s00330-018-5789-0

PubMed

researchmap

DOI： 10.1148/rg.2019194005

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.radcr.2019.02.016

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-018-5733-3

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To explore the usefulness of myocardial late iodine enhancement (LIE) and extracellular volume (ECV) quantification by using dual-energy cardiac CT. Materials and Methods: In this single-center retrospective study, a total of 40 patients were evaluated with LIE CT by using a dual-layer spectral detector CT system. Among these, 21 also underwent cardiac MRI. Paired image sets were created by using standard imaging at 120 kVp, virtual monochromatic imaging (VMI) at 50 keV, and iodine density imaging. The contrast-to-noise ratio and image quality were then compared. Two observers assessed the presence of LIE and calculated the interobserver agreements. Agreement between CT and cardiac MRI when detecting late-enhancing lesions and calculating the ECV was also assessed. Results: The contrast-to-noise ratio was significantly higher by using VMI than by using standard 120-kVp imaging, and the mean visual image quality score was significantly higher by using VMI than by using either standard or iodine density imaging. For interobserver agreement of visual detection of LIE, the agreement for VMI was excellent and the κ value (κ, 0.87) was higher than that for the standard 120-kVp (κ, 0.70) and iodine density (κ, 0.83) imaging. For detecting late-enhancing lesions, agreement with cardiac MRI was excellent by using VMI (κ, 0.90) and iodine density imaging (κ, 0.87) but was only good by using standard 120-kVp imaging (κ, 0.66). Quantitative comparisons of the ECV calculations by using CT and cardiac MRI showed excellent correlation (r 2 = 0.94). Conclusion: Dual-energy cardiac CT can assess myocardial LIE and quantify ECV, with results comparable to those obtained by using cardiac MRI.© RSNA, 2019See also the commentary by Litt in this issue.

DOI： 10.1148/ryct.2019180003

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2463/mrms.mp.2018-0132

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIMS: Mutant transthyretin (ATTRm) amyloidosis is a systemic disease caused by the deposition of amyloid fibrils derived from mutated transthyretin. Although cardiac involvement impacts the prognosis of patients with ATTRm amyloidosis, the incidence of cardiac events, such as bradyarrhythmia, ventricular tachycardia, and heart failure, has not been fully elucidated. The aim of this study was to evaluate the prognosis and predictors of clinical outcomes, including cardiac events, in patients with ATTRm amyloidosis in Japan. METHODS AND RESULTS: We evaluated 90 consecutive patients with ATTRm amyloidosis at Kumamoto University. ATTRm amyloidosis was diagnosed by the observation of both amyloid fibril deposition on tissue biopsy and a transthyretin mutation on sequential analysis. Sympathetic nerve activity was evaluated in 59 patients using 123-iodine metaiodobenzylguanidine (123 I-MIBG) imaging. The endpoint was a composite of all-cause death, hospitalization for heart failure, and implantation of a pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy defibrillator. Sixty-seven patients had the Val30Met mutation (74%). The composite endpoint occurred in 23 patients (26%): all-cause death (n = 6), hospitalization for worsening heart failure (n = 1), and implantation of an implantable cardioverter defibrillator (n = 6), cardiac resynchronization therapy defibrillator (n = 3), or pacemaker (n = 7). The 5-year incident rate for clinical outcomes was 19%. In a multivariate Cox hazard analysis, age [hazard ratio (HR): 1.07, 95% confidence interval (95% CI): 1.01-1.12, P = 0.015], PQ interval (HR: 1.01, 95% CI: 1.00-1.02, P = 0.042), interventricular septum thickness in diastole (HR: 1.25, 95% CI: 1.09-1.42, P = 0.001), and non-Val30Met mutation (HR: 4.31, 95% CI: 1.53-12.16, P = 0.006) were independent predictive factors of clinical outcomes. Kaplan-Meier analysis demonstrated a significantly higher probability of the composite endpoint in the non-Val30Met group than in the Val30Met group (log-rank test: P = 0.002) and in patients with left ventricular hypertrophy than in patients without left ventricular hypertrophy (log-rank test: P < 0.001). In patients who underwent 123 I-MIBG imaging, a delayed heart-to-mediastinum (HM) ratio <1.6 was a significant predictive factor of the composite endpoint (HR: 4.98, 95% CI: 1.73-14.37, P = 0.003) in the univariate Cox hazard analyses. Kaplan-Meier curve analysis showed that a delayed HM ratio <1.6 was associated with a poor prognosis (log-rank test: P = 0.001). CONCLUSIONS: Non-Val30Met mutation, septal hypertrophy, and a delayed HM ratio are useful predictors of clinical outcomes in patients with ATTRm amyloidosis in Japan. These results suggest that it is important to evaluate cardiac involvement in terms of morphological (left ventricular hypertrophy) and functional (cardiac denervation) perspectives using echocardiography and 123 I-MIBG imaging, respectively.

DOI： 10.1002/ehf2.12361

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE:: To evaluate the effects of virtual monochromatic imaging (VMI) using dual-layer spectral detector CT on the image quality of coronary CT angiography (CCTA) acquired by using a low contrast material (CM) dose. METHODS:: We used a VMI 50keV protocol with a 50%  CM dose (140  mgI kg-1) to scan 30 patients with renal insufficiency and a 120 kVp with the standard CM dose (280  mgI kg-1) to scan 30 controls without renal insufficiency. Quantitative parameters, including CT attenuation, image noise, and contrast-to-noise ratio (CNR), were measured. The visual image quality factors of contrast enhancement, image noise, beam-hardening artefact, vessel sharpness, and overall image quality were scored on a 4-point scale. RESULTS:: The mean CT attenuation of the ascending aorta was significantly higher for 50 keV VMI than for 120 kVp. Image noise was significantly lower under the 50 keV VMI. CNR and the mean visual score for contrast enhancement were significantly higher for 50 keV VMI. There were no significant differences in the other visual image quality parameters between the two protocols. CONCLUSION:: Dual-layer spectral detector CT using 50 keV VMI enabled reducing the CM dose by 50 % without CCAT image quality degradation in patients with renal insufficiency. ADVANCES IN KNOWLEDGE:: The VMI 50 keV protocol using dual-layer spectral detector CT and a CM dose reduced by 50 % (140 mgI kg-1) can improve the diagnostic image quality of CCTA.

DOI： 10.1259/bjr.20180215

PubMed

researchmap

記述言語：英語  

Late gadolinium enhancement imaging by cardiac magnetic resonance imaging (CMR) is the most reliable method for identifying cardiac involvement in patients with amyloidosis, and myocardial T1 mapping is a novel CMR technique that enables the noninvasive detection and quantification of myocardial amyloid burden. Although, base-to-apex gradient patterns of impairment in patients with cardiac amyloidosis have been reported on myocardial strain analysis using echocardiography, we could not find any other reports to demonstrate that myocardial T1 mapping on CMR can clearly identify a base-to-apex gradient pattern of cardiac impairment in a patient with cardiac amyloidosis.

DOI： 10.1016/j.radcr.2018.09.025

PubMed

researchmap

DOI： 10.1080/13506129.2019.1582021

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.5603/CJ.2019.0013

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Coronary Computed Tomography Angiography (CTA) has become one of the most important diagnostic imaging modalities for the evaluation of coronary artery diseases. During coronary computed CTA, sufficient vascular enhancement is essential for the accurate detection and evaluation of lesions in the coronary arteries. To obtain optimal contrast enhancement and perform appropriate clinical coronary CTA, physicians, radiologists, and radiology technologists should acquire a basic knowledge of contrast injection protocols. CONCLUSION: This review article summarizes the basic concepts of contrast injection protocols for coronary CTA.

DOI： 10.2174/1573403X14666180918102031

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.crad.2018.08.010

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Repeatability of quantitative assessment of atherosclerotic plaques is important for the accurate detection of high-risk plaques in coronary CT angiography (CTA). We assessed the effect of heart rate (HR) on plaque CT number using a coronary artery model and a cardiac phantom capable of simulating cardiac motion. The coronary artery model with luminal stenosis on a cardiac phantom was imaged with a simulated HR of 0, 50, 60, and 70 beats per minute using a 320-row CT scanner. We reconstructed CT images for cardiac diastolic phases (for 75% R-R interval) using filtered back projection (FBP), hybrid iterative reconstruction (AIDR3D), and model-based iterative reconstruction (FIRST). Two observers measured plaque attenuation in the lesion with 75% stenosis. The coefficient of determination (R2) was obtained to evaluate interobserver agreement. At HR 70, FIRST improved the correlation between two observers compared with FBP and AIDR3D (FIRST: R2 = 0.68, p < 0.05; FBP: R2 = 0.29, p = 0.31; AIDR3D: R2 = 0.22, p = 0.18). These R2 at HR 70 were lower compared with at HR 50 (FIRST: R2 = 0.92, p < 0.05; FBP: R2 = 0.83, p < 0.05; AIDR3D: R2 = 0.87, p < 0.05) and HR 0 (FIRST: R2 = 0.97, p < 0.05; FBP: R2 = 0.89, p < 0.05; AIDR3D: R2 = 0.95, p < 0.05). Higher HR affected plaque measurement repeatability in coronary CTA. FIRST may improve plaque measurement repeatability at the higher HR compared with FBP and AIDR3D.

DOI： 10.1007/s10554-018-1415-0

PubMed

researchmap

記述言語：英語  

BACKGROUND: Esophageal injury (EI) is a serious complication that occurs after catheter ablation of atrial fibrillation (AF), however predictable factor of EI is unclear. METHODS: Among 308 patients who underwent AF ablation, upper gastrointestinal tract endoscopy was performed the next day after ablation to examine for EI. To define the primary factor that predicts EI, patients' characteristics, number and amount of radiofrequency energy applied to the posterior wall, ablation procedure, and the shortest distance between esophagus and posterior left atrium measured on contrast computed tomography (SD-CT) were analyzed. RESULTS: EI was found in 27 patients (8.8%). There were no significant differences in the patient characteristics, number and amount of radiofrequency energy applied to posterior wall or ablation procedure between patients with (Injury Group) and without EI (Non-Injury Group). However, SD-CT in the Injury Group was significantly shorter than that in Non-Injury Group (2.3±0.6mm vs 4.1±0.9mm, p<0.001). The area under a receiver operating characteristic curve using SD-CT as a predictive marker in EI patients was 0.988 (p<0.001). When the cut-off value of SD-CT was set at 2.9mm, the sensitivity and specificity for EI diagnosis were 92.3% and 96.8%, and the positive predictive value and negative predictive value were 0.75 and 0.99, respectively. CONCLUSIONS: EI observed after catheter ablation of AF was closely associated with the SD-CT. Patients with SD-CT below 2.9mm have a potential risk of EI and thus must be strictly followed.

DOI： 10.1016/j.jjcc.2018.05.009

PubMed

researchmap

DOI： 10.1016/j.clinimag.2018.01.020

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejrad.2018.09.011

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejrad.2018.09.017

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11604-018-0771-y

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1148/rg.2018180041

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jccase.2018.05.003

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00380-017-1104-2

Scopus

PubMed

researchmap

DOI： 10.1080/13506129.2018.1424625

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer New York LLC  

Cardiac computed tomography (CT) now plays an important role in emergency settings because of its accessibility and fast acquisition time, which cardiac magnetic resonance imaging (CMR) cannot match. Although cardiac CT was originally conceived for the assessment of the coronary artery tree, it has evolved to embrace several non-coronary applications. These include myocardial assessment, resulting in myocardial characterization comparable with that of CMR and cardiac CT for late enhancement imaging. In this report, we describe a patient with takotsubo cardiomyopathy who underwent a comprehensive assessment using cardiac CT. This technique enabled to identify the condition of the coronary arteries and to evaluate the four-dimensional left ventricular function and myocardial late iodine enhancement immediately. The information obtained was similar to that provided by CMR
however, cardiac CT is more practical than CMR in emergency settings. Comprehensive assessment by cardiac CT can be beneficial for a noninvasive evaluation of patients with suspected takotsubo cardiomyopathy.

DOI： 10.1007/s10140-018-1610-2

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejmp.2018.04.388

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1097/MD.0000000000010810

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1097/MD.0000000000010447

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1259/bjr.20170632

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1097/MD.0000000000010231

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.2463/mrms.mp.2017-0037

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00234-018-1982-8

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.acra.2017.10.008

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-017-5114-3

Scopus

PubMed

researchmap

DOI： 10.1007/s00380-017-1069-1

PubMed

researchmap

DOI： 10.1016/S0735-1097(18)31718-2

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.crad.2017.09.006

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1161/CIRCIMAGING.117.007277

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Verlag  

Objectives: The current study evaluated the clinical usefulness of the gradient and spin-echo (GRASE) sequence with single breath-hold in 3.0 T magnetic resonance cholangiopancreatography (MRCP). We compared the acquisition time and image quality between GRASE and breath navigator-triggered 3D turbo spin echo (3D TSE). Methods: We examined 54 consecutive patients who underwent MRCP with GRASE and 3D TSE. We compared the image acquisition time and contrast-to-noise ratio (CNR) between the common bile duct (CBD) and liver. Overall image quality, blurring, motion artifacts and CBD visibility were scored on a 4-point scale by two radiologists. Paired t-tests were used to compare the variables. Results: The mean image acquisition time was 95 % shorter with the GRASE than with 3D TSE (GRASE: 20 s
3D TSE: 6 min 27 s). The CNR of GRASE was significantly higher than that of 3D TSE (GRASE: 25.4 ± 13.9 vs. 3D TSE: 18.2 ± 9.6, p &lt
0.01). All qualitative scores for GRASE were significantly better than those for 3D TSE. Conclusions: 3.0 T MRCP with GRASE sequence with single breath-hold significantly improved the CNR of CBD with a 95 % shorter acquisition time compared with conventional 3D MRCP with 3D TSE. Key Points: • MRCP acquisition time was 95% shorter with GRASE than with 3D TSE.• Overall image quality of GRASE was significantly better than 3D TSE.• Pancreaticobiliary tree visibility with GRASE was better than that with 3D TSE.

DOI： 10.1007/s00330-017-5240-y

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the effect of a composite radiofrequency (RF) pulse on saturation recovery (SR) myocardial T1 mapping using a 3T MR system. MATERIALS AND METHODS: Phantom and in vivo studies were performed with a clinical 3T MR scanner. Accuracy and reproducibility of the SR T1 mapping using conventional and composite RF pulses were first compared in phantom experiments. An in vivo study was performed of 10 healthy volunteers who were imaged with conventional and composite RF pulse methods twice each. In vivo reproducibility of myocardial T1 value and the inter-segment variability were assessed. RESULTS: The phantom study revealed significant differences in the mean T1 values between the two methods, and the reproducibility for the composite RF pulse was significantly smaller than that for the conventional RF pulse. For both methods, the correlations of the reference and measured T1 values were excellent (r2 = 0.97 and 0.98 for conventional and composite RF pulses, respectively). The in vivo study showed that the mean T1 value for composite RF pulse was slightly lower than that for conventional RF pulse, but this difference was not significant (P = 0.06). The inter-segment variability for the composite RF pulse was significantly smaller than that for conventional RF pulse (P < 0.01). Inter-scan correlations of T1 measurements of the first and second scans were highly and weakly correlated to composite RF pulses (r = 0.83 and 0.29, respectively). CONCLUSION: SR T1 mapping using composite RF pulse provides accurate quantification of T1 values and can lessen measurement variability and enable reproducible T1 measurements.

DOI： 10.2463/mrms.mp.2016-0092

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Different CT scanners have different X-ray spectra and photon energies indicating that contrast enhancement vary among scanners. However, this issue has not been fully validated; therefore, we performed phantom and clinical studies to assess this difference. METHODS: Two scanners were used: scanner-A and scanner-B. In the phantom study, we compared the contrast enhancement between the scanners at tube voltage peaks of 80, 100 and 120 kVp. Then, we calculated the effective energies of the two CT scanners. In the clinical study, 40 patients underwent abdominal scanning with scanner-A and another 40 patients with scanner-B, with each group using the same scanning protocol. The contrast enhancement of abdominal organs was assessed quantitatively (based on the absolute difference between the attenuation of unenhanced scans and contrast-enhanced scans) and qualitatively. A two-tailed independent Student's t-test and or the Mann-Whitney U test were used to compare the discrepancies. RESULTS: In the phantom study, contrast enhancement for scanner-B was 36.9, 32.6 and 30.8% higher than that for scanner-A at 80, 100 and 120 kVp, respectively. The effective energies were higher for scanner-A than for scanner-B. In the quantitative analysis for the clinical study, scanner-B yielded significantly better contrast enhancement of the hepatic parenchyma, pancreas, kidney, portal vein and inferior vena cava compared with that of scanner-A. The mean visual scores for contrast enhancement were also significantly higher on images obtained by scanner-B than those by scanner-A. CONCLUSION: There were significant differences in contrast enhancement of the abdominal organs between the compared CT scanners from two different vendors even at the same scanning and contrast parameters. Advances in knowledge: Awareness of the impact of different X-ray energies on the resultant attenuation of contrast material is important when interpreting clinical CT images.

DOI： 10.1259/bjr.20170285

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: We compared the effect of a dual-region-of-interest (ROI) bolus-tracking technique on interpatient variability of arterial contrast enhancement with that of the conventional bolus-tracking technique in coronary computed tomographic angiography (CTA) on a 320-row scanner. METHODS: This study included 100 patients who underwent coronary CTA using one of two protocols: (1) 50 patients underwent scanning using a conventional single-ROI bolus-tracking technique (P-single) with an ROI placed in the ascending aorta, and (2) 50 patients underwent scanning using a dual-ROI technique (P-dual) with two ROIs placed in the pulmonary trunk and the ascending aorta. CT attenuation in the ascending aorta and coronary arteries, and the interpatient variability were compared between the two scanning protocols. RESULTS: The mean CT attenuation of the ascending aorta and coronary arteries tended to be higher for P-dual than for P-single, but the difference was not significant (p = 0.08-0.30). The interpatient variability of contrast enhancement (SD of the CT attenuation) was significantly smaller for P-dual than for P-single (p < 0.01). CONCLUSION: The dual-ROI bolus-tracking technique can reduce interpatient variability of arterial contrast enhancement in coronary CTA on a 320-row scanner. Advances in knowledge: The use of a dual-ROI bolus-tracking technique can provide sufficient and consistent arterial enhancement of coronary CTA.

DOI： 10.1259/bjr.20170541

PubMed

researchmap

DOI： 10.1016/j.ejrad.2017.11.009

PubMed

researchmap

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Objectives This study sought to explore the potential role of non-contrast T1 mapping for the detection and quantification of cardiac involvement in familial amyloid polyneuropathy (FAP).
Methods Japanese patients with FAP [n = 41, age 53.2 +/- 13.9 years, genotype Val30Met (n = 25), non-Val30Met (n = 16)] underwent cardiac magnetic resonance imaging that included T1 mapping (saturation-recovery method) and late gadolinium-enhanced (LGE) imaging on a 3.0-T MR scanner. Their native T1 was measured on mid-ventricular short-axis images and compared with 30 controls.
Results Of the 41 FAP patients 29 were LGE positive. The native T1 was significantly higher in FAP patients than in the controls (1,634.1 +/- 126.3 ms vs. 1,432.4 +/- 69.0 ms, p &lt; 0.01), significantly higher in LGE-positive- than LGE-negative FAP patients (1,687.1 +/- 104.4 ms vs. 1,505.4 +/- 68.5 ms, p &lt; 0.01), and significantly higher in LGE-negative FAP patients than the controls (p &lt; 0.01). A native T1 cutoff value of 1,610 ms yielded 85.4% accuracy for identifying LGE-positive FAP. The native T1 significantly correlated with the interventricular septum wall thickness, the left ventricular mass, the LGE volume, the plasma B-type natriuretic peptide level, and the E/e' ratio (all p &lt; 0.01).
Conclusion T1 mapping is of high diagnostic accuracy for the detection of LGE-positive FAP. The native myocardial T1 may be correlated with the severity of cardiac amyloid deposition.

DOI： 10.1007/s00330-017-4845-5

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objectives The objective of this study is to evaluate the usefulness of iterative model reconstruction designed for brain computed tomography (CT) (IMR-Neuro) for the diagnosis of acute ischemic stroke.
Methods This retrospective study included 20 patients with acute middle cerebral artery infarction who have undergone brain CT and 20 nonstroke patients (control). We reconstructed axial images with filtered back projection (FBP) and IMR-Neuro (slice thickness, 1 and 5 mm). We compared the CT number of the infarcted area, the image noise, contrast, and the contrast to noise ratio of the infarcted and the noninfarcted areas between the different reconstruction methods. We compared the performance of 10 radiologists in the detection of parenchymal hypoattenuation between 2 techniques using the receiver operating characteristic (ROC) techniques with the jackknife method.
Results The image noise was significantly lower with IMR-Neuro [5 mm: 2.5 Hounsfield units (HU) 0.5, 1 mm: 3.9 HU +/- 0.5] than with FBP (5 mm: 4.9 HU +/- 0.5, 1 mm: 10.1 HU +/- 1.4) (P &lt; 0.01). The contrast to noise ratio was significantly greater with IMR-Neuro (5 mm: 2.6 +/- 2.1, 1 mm: 1.6 +/- 1.3) than with FBP (5 mm: 1.2 +/- 1.0; 1 mm: 0.6 +/- 0.5) (P &lt; 0.01). The value of the average area under the receiver operating curve was significantly higher with IMR-Neuro than FBP (5 mm: 0.79 vs 0.74, P = 0.04; 1 mm: 0.76 vs 0.69, P = 0.04).
Conclusions Compared with FBP, IMR-Neuro improves the image quality and the performance for the detection of parenchymal hypoattenuation with acute ischemic stroke.

DOI： 10.1097/RCT.0000000000000626

Web of Science

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejrad.2017.09.012

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jcct.2017.09.010

Scopus

PubMed

researchmap

DOI： 10.1002/ccr3.1180

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.clinimag.2017.06.006

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: To investigate the stabilities of plaque attenuation and coronary lumen for different plaque types, stenotic degrees, lumen densities, and reconstruction methods using coronary vessel phantoms and the visualization of coronary plaques in clinical patients through coronary computed tomography (CT) angiography.
Materials and Methods: We performed 320-detector volume scanning of vessel tubes with stenosis and a tube without stenosis using three types of plaque CT numbers. The stenotic degrees were 50% and 75%. Images were reconstructed with filtered back projection (FBP) and two types of iterative reconstructions (AIDR3D and FIRST [forward-projected model-based iterative reconstruction solution]); with stenotic CT number of approximately 40, 80, and 150 HU (Hounsfield unit), respectively. In each case, the tubing of the coronary vessel was filled with diluted contrast material and distilled water to reach the target lumen CT numbers of approximately 350 HU and 450 HU, and 0 HU, respectively. Peak lumen and plaque CT numbers were measured to calculate the lumen-plaque contrast. In addition, we retrospectively evaluated the image quality with regard to coronary arterial lumen and the plaque in 10 clinical patients on a 4-point scale.
Results: At 50% stenosis, the plaque CT number with contrast enhancement increased for FBP and AIDR3D, and the difference in the plaque CT number with and without contrast enhancement was 15-44 HU for FBP and 10-31 HU for AIDR3D. However, the plaque CT number for FIRST had a smaller variation and the difference with and without contrast enhancement was -12 to 8 HU. The visual evaluation score for the vessel lumen was 2.8 +/- 0.6, 3.5 +/- 0.5, and 3.7 +/- 0.5 for FBP, AIDR3D, and FIRST, respectively.
Conclusions: The FIRST method controls the increase in plaque density and the lumen-plaque contrast. Consequently, it improves the visualization of coronary plaques in coronary CT angiography.

DOI： 10.1016/j.acra.2017.02.006

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-017-4775-2

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-017-4773-4

Scopus

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10140-017-1511-9

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objectives: The aim of this study was to compare the image quality, the degree of artifacts and the percentage of timing of the optimal hepatic arterial phase (HAP) between test-bolus and bolus-tracking methods on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI).
Methods: In this prospective study, 60 patients who underwent 3-dimensional dynamic Gd-EOB-DTPA-enhanced hepatic 3-T MRI were enrolled in this study. We randomly assigned the 30 patients to the bolustracking method, and another 30 patients to the test-bolus method. Signal-to-noise ratios of the liver and spleen in HAP were compared in the 2 groups. Two radiologists independently assessed the ratio of optimal timing of HAP and the degree of ringing and motion artifacts of the 2 protocols.
Results: The signal-to-noise ratios of the liver (24.0 [SD, 6.4] vs 20.4 [SD, 4.0]) and spleen (30.0 [SD, 13.3] vs 23.6 [SD, 9.9]) were significantly higher in the test-bolus protocol than in the bolus-tracking protocol. The ratio of optimal timing was also significantly higher with the test-bolus protocol than with the bolus-tracking protocol (76.7% vs 40.0%). The degree of ringing and motion artifacts of test-bolus protocol was significantly lower than that of the bolus-tracking protocol (P &lt; 0.01).
Conclusions: The test-bolus protocol in dynamic 3-T MRI can yield better qualitative image quality and more optimal timing of HAP images, while reducing the degree of artifacts compared with the bolustracking protocol.

DOI： 10.1097/RCT.0000000000000583

Web of Science

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1148/radiol.2017161966

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-016-4679-6

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER IRELAND LTD  

Purpose: To determine the utility of liver T1-mapping on gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance (MR) imaging for the measurement of liver functional reserve compared with the signal intensity (SI) based parameters, technetium-(99m)-galactosyl serum albumin (Tc-99m-GSA) scintigraphy and indocyanine green (ICG) clearance.
Materials and methods: This retrospective study included 111 patients (Child-Pugh-A 90; -B 21) performed with both Gd-EOB-DTPA enhanced liver MR imaging and Tc-99m-GSA (76 patients with ICG). Receiver operating characteristic (ROC) curve analysis was performed to compare diagnostic performances of T1-relaxation-time parameters [pre-(T1pre) and post-contrast (T1hb) Gd-EOB-DTPA], SI based parameters [relative enhancement (RE), liver-to-muscle-ratio (LMR), liver-to-spleen-ratio (LSR)] and Tc-99m-GSA scintigraphy blood clearance index (HH15)] for Child-Pugh classification. Pearson's correlation was used for comparisons among T1-relaxation-time parameters, SI-based parameters, HH15 and ICG.
Results: A significant difference was obtained for Child-Pugh classification with T1hb,triangle T1, all SI based parameters and HH15. T1hb had the highest AUC followed by RE, LMR, LSR,triangle T1, HH15 and T1pre. The correlation coefficients with HH15 were T1pre 0.22, T1hb 0.53,triangle T1 -0.38 of T1 relaxation parameters; RE -0.44, LMR -0.45, LSR -0.43 of SI-based parameters. T1hb was highest for correlation with HH15. The correlation coefficients with ICG were T1pre 0.29, T1hb 0.64,triangle T1 -0.42 of T1 relaxation parameters; RE -0.50, LMR -0.61, LSR -0.58 of SI-based parameters; 0.64 of HH15. Both T1hb and HH15 were highest for correlation with ICG.
Conclusion: T1 relaxation time at post-contrast of Gd-EOB-DTPA (T1hb) was strongly correlated with ICG clearance and moderately correlated HH15 with Tc-99m-GSA. T1hb has the potential to provide robust parameter of liver functional reserve.

DOI： 10.1016/j.ejrad.2017.05.011

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPANESE CIRCULATION SOC  

Background: We explored the usefulness of myocardial strain analysis on cardiac magnetic resonance imaging (CMR) scans for the identification of cardiac amyloidosis.
Methods and Results: The 61 patients with systemic amyloidosis underwent 3.0-T CMR, including CMR tagging and late-gadolinium enhanced (LGE) imaging. The circumferential strain (CS) of LGE-positive and LGE-negative patients was measured on midventricular short-axis images and compared. Logistic regression modeling of CMR parameters was performed to detect patients with LGE-positive cardiac amyloidosis. Of the 61 patients with systemic amyloidosis 48 were LGE-positive and 13 were LGE-negative. The peak CS was significantly lower in the LGE-positive than in the LGE-negative patients (-9.5 +/- 2.3 vs. -13.3 +/- 1.4%, P&lt;0.01). The variability in the peak CS time was significantly greater in the LGE-positive than in the LGE-negative patients (46.1 +/- 24.5 vs. 21.2 +/- 20.1 ms, P&lt;0.01). The peak CS significantly correlated with clinical biomarkers. The sensitivity, specificity, and accuracy of the diagnostic model using CS parameters for the identification of LGE-positive amyloidosis were 93.8%, 76.9%, and 90.2%, respectively.
Conclusions: Myocardial strain analysis by CMR helped detect LGE-positive amyloidosis without the need for contrast medium. The peak CS and variability in the peak CS time may correlate with the severity of cardiac amyloid deposition and may be more sensitive than LGE imaging for the detection of early cardiac disease in patients with amyloidosis.

DOI： 10.1253/circj.CJ-16-1259

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To investigate the usefulness of modifying scanning parameters based on the size-specific dose estimate (SSDE) for a breast-dose reduction for chest CT.
We scanned 26 women with a fixed volume CT dose index (CTDIvol) (15 mGy) and another 26 with a fixed SSDE (15 mGy) protocol (protocol 1 and 2, respectively). In protocol 2, tube current was calculated based on the patient habitus obtained on scout images. We compared the mean breast dose and the inter-patient breast dose variability and performed linear regression analysis of the breast dose and the body mass index (BMI) of the two protocols.
The mean breast dose was about 35 % lower under protocol 2 than protocol 1 (10.9 mGy vs. 16.8 mGy, p &lt; 0.01). The inter-patient breast dose variability was significantly lower under protocol 2 than 1 (1.2 mGy vs. 2.5 mGy, p &lt; 0.01). We observed a moderate negative correlation between the breast dose and the BMI under protocol 1 (r = 0.43, p &lt; 0.01); there was no significant correlation (r = 0.06, p = 0.35) under protocol 2.
The SSDE-based protocol achieved a reduction in breast dose and in inter-patient breast dose variability.
aEuro cent CT scan parameters can be modified based on the pre-scan SSDE.
aEuro cent The pre-scan SSDE is useful for a breast dose reduction.
aEuro cent The fixed SSDE protocol reduced individual variations in the breast dose.

DOI： 10.1007/s00330-016-4618-6

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

We evaluated whether donor computed tomography (CT) with a combined technique of lower tube voltage and iterative reconstruction (IR) can provide sufficient preoperative information for liver transplantation.We retrospectively reviewed CT of 113 liver donor candidates. Dynamic contrast-enhanced CT of the liver was performed on the following protocol: protocol A (n=70), 120-kVp with filtered back projection (FBP); protocol B (n=43), 100-kVp with IR. To equalize the background covariates, one-to-one propensity-matched analysis was used. We visually compared the score of the hepatic artery (A-score), portal vein (P-score), and hepatic vein (V-score) of the 2 protocols and quantitatively correlated the graft volume obtained by CT volumetry (graft-CTv) under the 2 protocols with the actual graft weight.In total, 39 protocol-A and protocol-B candidates showed comparable preoperative clinical characteristics with propensity matching. For protocols A and B, the A-score was 3.870.73 and 4.51 +/- 0.56 (P<.01), the P-score was 4.92 +/- 0.27 and 5.0 +/- 0.0 (P=.07), and the V-score was 4.23 +/- 0.78 and 4.82 +/- 0.39 (P<.01), respectively. Correlations between the actual graft weight and graft-CTv of protocols A and B were 0.97 and 0.96, respectively.Liver-donor CT imaging under 100-kVp plus IR protocol provides better visualization for vascular structures than that under 120-kVp plus FBP protocol with comparable accuracy for graft-CTv, while lowering radiation exposure by more than 40% and reducing contrast-medium dose by 20%.

DOI： 10.1097/MD.0000000000006973

Web of Science

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

DOI： 10.1016/j.jcct.2017.01.005

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objective: The aim of this study was to evaluate the effect of cardiac output (CO) on aortic peak enhancement using protocols with different contrast material (CM) injection durations.
Methods: We used a flow phantom that simulated the human circulatory system. Contrast material was injected at a rate of 4.0 mL/s for a period of 2.5, 5, 10, 15, or 20 seconds for a CO of 2.8, 4.2, and 5.6 L/min. Single-level serial computed tomography scans of the simulated aorta were acquired after the start of CM delivery, and aortic peak enhancement was recorded under the different injection protocols.
Results: Under a long injection duration protocol (20 seconds), a decrease in CO increased aortic peak enhancement proportionally (CO of 2.8 L/min, 420 Hounsfield units [HU]; CO of 4.2 L/min, 365 HU; CO of 5.6 L/min, 291 HU). However, this effect was decreased under shorter injection duration protocols (5, 10, and 15 seconds); under the shortest (2.5-second) injection duration protocol, a decrease in CO resulted in a decrease in aortic peak enhancement (CO of 2.8 L/min, 36 HU; CO of 4.2 L/min, 51 HU; CO of 5.6 L/min, 55 HU).
Conclusions: The magnitude of the effect of CO on aortic peak enhancement depends on the CM injection duration.

DOI： 10.1097/RCT.0000000000000541

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Little is known about the significance of asymptomatic intra-cranial lesions (ICL) identified by brain MRI in coronary artery disease (CAD) patients. Silent cerebral lesions are suggested to be associated with arterial stiffness in healthy subjects. We investigated whether subclinical ICL are associated with arterial stiffness and the prognosis in CAD patients without medical history of cerebrovascular diseases. We recruited CAD patients who required percutaneous coronary intervention (PCI), did not meet exclusion criteria, and agreed with MRI before PCI. Subjects were divided into two groups according to the presence of ICL of cerebral microbleeds or lacunar infarction. Arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV). Clinical outcome was defined as a composite of cardiovascular death, non-fatal myocardial infarction, stroke, unstable angina and heart failure. In total, 149 patients underwent brain MRI. Patients with ICL (n= 55) had significantly higher baPWV than those without ICL (1591-2204 vs. 1450-1956 cm per sec; P= 0.009). A multivariate analysis showed that male sex (odds ratio (OR), 3.15; 95% confidence interval (CI), 1.38-7.20; P= 0.006) and baPWV (OR, 1.001; 95% CI, 1.000-1.002; P= 0.023) were predictors of ICL. In total, 12 patients experienced a cardiovascular event. The Kaplan-Meier analysis indicated a significantly higher incidence of cardiovascular events in patients with ICL (log-rank test: P= 0.018). Multivariate Cox proportional hazards analyses indicated that ICL finding was a significant predictor of clinical outcome (hazard ratio, 3.41; 95% CI, 1.02-11.5; P= 0.047). Patients with subclinical ICL had a higher baPWV and worse prognoses than those without ICL.

DOI： 10.1038/hr.2016.159

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: We compared the effect of iterative model reconstruction (IMR), filtered back projection (FBP), and hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) scoring.
Materials and Methods: CAC scans of 30 consecutive patients (18 men and 12 women, age 70.1 +/- 12.2 years) were reconstructed with FBP, HIR, and IMR, and the image noise was measured on all images. Two radiologists independently measured the CAC scores using semiautomated software, and interobserver agreement was evaluated. Statistical analysis included the Spearman correlation coefficient and Bland-Altman analysis.
Results: The mean image noise on FBP, HIR, and IMR images was 48.0 +/- 7.9, 29.6 +/- 4.8, and 9.3 +/- 1.3 Hounsfield units, respectively. The difference among all reconstruction combinations was significant (P &lt;.01). The CAC score on HR and IMR scans was 4.2% and 8.9% lower, respectively, than the CAC score on FBP images. There was no significant difference in the mean CAC score among the three reconstructions. The interobserver correlation was excellent for all three reconstructions (r(2) = 0.96 FBP, 0.99 HIR, 0.99 IMR); the best Bland-Altman measure of agreement was with IMR, followed by HIR and FBP.
Conclusion: For CAC scoring, IMR can reduce the image noise and blooming artifacts, and consequently lowers the measured CAC score. IMR can lessen measurement variability and yield stable, reproducible measurements.

DOI： 10.1016/j.acra.2016.11.003

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00234-016-1776-9

PubMed

researchmap

記述言語：英語   出版者・発行元：JAPANESE CIRCULATION SOC  

DOI： 10.1253/circj.CJ-16-0873

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1177/2058460117693463

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER IRELAND LTD  

Backgrounds: The relationship between microvascular dysfunction and plasma B-type natriuretic peptide (BNP) levels remains unclear in heart failure (HF) patients with cardiac fibrosis.
Methods: This study evaluated 55 consecutive non-ischemicHF patients in an effort to determine the relationship between endothelial independent coronarymicrovascular dysfunction and plasmaBNP levels, aswell aswhether each measure is correlated with myocardial fibrosis. We evaluated plasma BNP levels in patients with stable HF. We used cardiac catheterization to measure trans-cardiac BNP release levels, measuring from the coronary sinus and the aortic root, and coronary flow reserve (CFR). Patients also underwent cardiacmagnetic resonance imaging to evaluate for the presence of late gadolinium enhancement (LGE), as an indicator of cardiac fibrosis.
Results: CFR in cardiac catheterization was significantly and inversely correlated with plasma BNP levels (r = 0.336, p = 0.012) and trans-cardiac BNP release levels (r - 0.347, p - 0.041). Thirty-three patients were LGE-positive. CFR was significantly correlated with plasma BNP levels in the LGE-positive group (r = 0.349, p = 0.046), but this correlation was not significant in the LGE-negative group. (r= 0.338, p = 0.125). Multivariate logistic regression analysis revealed that a plasma BNP levels &gt;180 pg/ml at stable HF condition was significant and independent predictor of CFR &lt; 2.5 in all patients (p = 0.035, odds ratio: 5.2, 95% confidence interval: 1.1-29.0), and in the LGE-positive group (p= 0.040, odds ratio: 5.4, 95% confidence interval: 1.1-27.2).
Conclusions: In non-ischemic HF patients especially those with cardiac fibrosis, endothelial independent microvascular dysfunction is closely correlated with plasma BNP levels, and ventricular wall tension. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.ijcard.2016.11.054

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Myocardial fibrosis and microvascular dysfunction are key determinants of outcome in heart failure (HF); we examined their relationship in patients with HF. Our study included 61 consecutive patients with HF but without coronary stenosis. All underwent gadolinium-enhanced cardiac magnetic resonance to evaluate late gadolinium enhancement (LGE) and an acetylcholine (ACh) provocation test to evaluate microvascular dysfunction. During the ACh provocation test, we sampled blood simultaneously from the coronary sinus and aortic root to compare lactate concentrations. We quantified coronary blood flow volume using an intracoronary Doppler-tipped guidewire. We detected LGE in 34 patients (LGE-positive); 27 were LGE-negative. Coronary blood flow volume increased significantly after the ACh provocation test only in LGE-negative patients (before vs. after ACh, 47.5 +/- A 36.8 vs. 69.2 +/- A 48.0 ml/min, respectively; p = 0.004). The myocardial lactate extraction ratio (LER) significantly decreased after the ACh test in both groups (LGE-negative, p = 0.001; LGE-positive, p &lt; 0.001), significantly more so in the LGE-positive group (p = 0.017). Multivariate logistic regression analysis showed that a post-ACh LER &lt; 0 (indicating myocardial lactate production) was a significant predictor of LGE-positivity (odds ratio 4.54; 95 % confidence interval 1.38-14.93; p = 0.013). In the LGE-positive group, an LGE volume greater than the median significantly predicted a post-ACh LER of &lt; 0 (p = 0.042; odds ratio 6.02; 95 % confidence interval 1.07-33.86). ACh-provoked coronary vasomotor abnormality is closely correlated with myocardial fibrosis in patients with HF but without organic coronary stenosis. Coronary vasomotor abnormalities in fibrotic myocardium may worsen HF.

DOI： 10.1007/s00380-016-0816-z

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: Transluminal-attenuation-gradient (TAG) may reflect patient characteristics and physiological parameters. Furthermore, TAG may be affected by factors such as the CT scanner speed, scanning method, scan timing after contrast-medium (CM) injection, and the injection methods. The purpose of our study was to investigate quantitative TAG at different scan timing points after CM injection for coronary CT angiography.
Materials and methods: Using a CM flow phantom and two types of connecting tube mimicking 0% and 70% coronary artery stenosis, we performed 320-detector volume scanning. The heart rate was set at 60 bpm and cardiac-output (CO) at 2.0 and 4.0 l/min, respectively. The acquisition time repeated at 0.5-s intervals for 40 and 25 s at a CO of 2.0- and 4.0 l/min. We measured the CT number on the same slice level, calculated the time-density-curve (TDC) and the TAG at each time point.
Results: At COs of 2.0 and 4.0 l/min at 0% stenosis, TAG exhibited smaller variations (-3.02 to +0.55 HU/cm at 2.0 l/min, -2.63 to +0.43 HU/cm at 4.0 l/min) than at 70% stenosis at each time point along the TDC. Compared with a CO at 2.0 l/min with 70% stenosis, the TAG curve for a CO at 4.0 l/min gradually changed with time (-6.64 to +1.18 HU/cm at 2.0 l/min vs. -3.46 to +2.75 HU/cm at 4.0 l/min).
Conclusion: The TAG value was affected by scan timing after CM injection and by CO although the size of the connecting tube with and without stenosis was identical. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2016.10.011

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: The purpose of this study was to evaluate the noise and image quality of images reconstructed with a knowledge-based iterative model reconstruction (knowledge-based IMR) in ultra-low dose cardiac computed tomography (CT).
Materials and Methods: We performed submillisievert radiation dose coronary CT angiography on 43 patients. We also performed a phantom study to evaluate the influence of object size with the automatic exposure control phantom. We reconstructed clinical and phantom studies with filtered back projection (FBP), hybrid iterative reconstruction (hybrid IR), and knowledge-based IMR. We measured effective dose of patients and compared CT number, image noise, and contrast noise ratio in ascending aorta of each reconstruction technique. We compared the relationship between image noise and body mass index for the clinical study, and object size for phantom study.
Results: The mean effective dose was 0.98 +/- 0.25 mSv. The image noise of knowledge-based IMR images was significantly lower than those of FBP and hybrid IR images (knowledge-based IMR: 19.4 +/- 2.8; FBP: 126.7 +/- 35.0; hybrid IR: 48.8 +/- 12.8, respectively) (P &lt; .01). The contrast noise ratio of knowledge based IMR images was significantly higher than those of FBP and hybrid IR images (knowledge based IMR: 29.1 +/- 5.4; FBP: 4.6 +/- 1.3; hybrid IR: 13.1 +/- 3.5, respectively) (P &lt; .01). There were moderate correlations between image noise and body mass index in FBP (r = 0.57, P &lt; .01) and hybrid IR techniques (r = 0.42, P &lt; .01); however, these correlations were weak in knowledge-based IMR (r = 0.27, P &lt; .01).
Conclusion: Compared to FBP and hybrid IR, the knowledge-based IMR offers significant noise reduction and improvement in image quality in submillisievert radiation dose cardiac CT.

DOI： 10.1016/j.acra.2016.07.005

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: We investigated the effects of small focal spot (SFS) imaging and iterative model reconstruction (IMR) on the image quality of computed tomography angiographs (CTA) in patients with peripheral arterial disease.
Materials and Methods: We divided 60 consecutive patients with suspected or confirmed peripheral artery disease into two equal groups. One group underwent large focal spot scanning under our standard CTA protocol with hybrid iterative reconstruction (iDose(4)) (protocol 1), and the other underwent scanning with the SFS protocol and IMR (protocol 2). Quantitative image quality parameters, ie, arterial computed tomography attenuation, image noise, and the contrast-to-noise ratio, were compared and the visual image quality (depiction of each vessel) was scored on a 5-point scale.
Results: There was no significant difference in the arterial attenuation among all evaluated slice levels. The mean image noise was significantly lower under protocol 2 and the contrast-to-noise ratio was significantly higher at all slice levels. The visual scores assigned to the two protocols for the depiction of large vessels, such as the abdominal aorta and iliac artery, were comparable. However, the mean visual scores for small vessels in the lower extremities were significantly higher under protocol 2.
Conclusion: CTA with SFS and IMR yielded significantly better qualitative and quantitative image quality especially for small vessels.

DOI： 10.1016/j.acra.2016.05.011

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To assess whether 320-section low-dose dynamic volume computed tomography (320-LDVCT) with adaptive iterative dose reduction (AIDR) adds value to 3-T MRI for the preoperative evaluation of brain tumors.
The study population was comprised of 16 consecutive patients with brain tumors who, in addition to preoperative 3-T MRI, underwent 320-LDVCT with AIDR. Two radiologists independently evaluated the CT and MRI studies; one measured the relative cerebral blood volume (rCBV) in the tumor and contralateral brain on CT and MR perfusion maps. Interobserver agreement was assessed by kappa statistics.
In 3 of 16 patients (19 %), 320-LDVCT added diagnostic value to 3-T MRI studies with respect to the visualization of feeders (kappa = 0.77), and in 12 (75 %) it helped the delineation of venous structures (kappa = 0.71) and the relationship between the tumor and adjacent vessels (kappa = 0.85). The average standardized rCBV value was 12.2 +/- 2.40 (range 0.7-36.6) on MR and 8.80 +/- 2.77 (range 0.8-38.0) on CT perfusion studies; the correlation between these values was very strong (r = 0.92, p &lt; 0.0001). According to the neurosurgeons, 320-LDVCT added helpful information for surgery in 4 patients (25 %).
The 320-LDVCT can add value to 3-T MRI for the tumor feeders and relationship between the tumor and adjacent vessels.

DOI： 10.1007/s11604-016-0576-9

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

We investigated the effects of patient- and image acquisition-related factors on the image quality in coronary CT angiography (CCTA).
We enrolled 1197 patients (728 men; 65 +/- 12 years). All underwent CCTA under the routine scan protocol in 23 participating hospitals. The subjective image quality (3-point Likert scale: excellent, good, and poor) and the attenuation of the left and right coronary artery (LCA, RCA) were recorded; the effects of patient and image acquisition-related factors on vascular attenuation were then compared.
The mean LCA attenuation was 515.2 +/- 65.8 (excellent), 401.4 +/- 63.4 (good), and 319.5 +/- 47.6 HU (poor). The corresponding RCA attenuation was 496.6 +/- 67.6, 390.5 +/- 58.5, and 308.5 +/- 50.7 HU, respectively. Univariate analysis revealed significant associations between sufficient coronary attenuation (&gt; 400 HU) and the age, gender, body surface area (BSA), number of detectors, contrast synchronization, scan mode, and the fractional contrast dose. Multivariate analysis revealed that the bolus tracking method, prospective electrocardiogram gating, and fractional contrast dose were significantly associated with sufficient coronary enhancement.
BSA and fractional contrast dose are the most important patient- and image acquisition-related factors for sufficient coronary attenuation in CCTA.

DOI： 10.1007/s11604-016-0556-0

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Objectives We evaluated the effect of a single-energy metal artefact reduction (SEMAR) algorithm for metallic coil artefact reduction in body imaging.
Methods Computed tomography angiography (CTA) was performed in 30 patients with metallic coils (10 men, 20 women; mean age, 67.9 +/- 11 years). Non-SEMAR images were reconstructed with iterative reconstruction alone, and SEMAR images were reconstructed with the iterative reconstruction plus SEMAR algorithms. We compared image noise around metallic coils and the maximum diameters of artefacts from coils between the non-SEMAR and SEMAR images. Two radiologists visually evaluated the metallic coil artefacts utilizing a four-point scale: 1 = extensive; 2 = strong; 3 = mild; 4 = minimal artefacts.
Results The image noise and maximum diameters of the artefacts of the SEMAR images were significantly lower than those of the non-SEMAR images (65.1 +/- 33.0 HU vs. 29.7 +/- 10.3 HU; 163.9 +/- 54.8 mm vs. 10.3 +/- 19.0 mm, respectively; P &lt; 0.001). Better visual scores were obtained with the SEMAR technique (3.4 +/- 0.6 vs. 1.0 +/- 0.0, P &lt; 0.001).
Conclusions The SEMAR algorithm significantly reduced artefacts caused by metallic coils compared with the non-SEMAR algorithm. This technique can potentially increase CT performance for the evaluation of post-coil embolization complications.

DOI： 10.1007/s00330-015-3950-6

Web of Science

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-016-4435-y

Scopus

PubMed

researchmap

記述言語：英語   出版者・発行元：ELSEVIER IRELAND LTD  

DOI： 10.1016/j.ijcard.2016.01.051

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SAGE PUBLICATIONS LTD  

Background: Model-based type iterative reconstruction algorithms with fast reconstruction times are now available. The clinical feasibility of their reconstruction has not been evaluated adequately.
Purpose: To investigate the effects of model-based type iterative reconstruction, i.e. iterative model reconstruction (IMR), with fast reconstruction time on the qualitative and quantitative image quality at low-dose chest computed tomography (CT).
Material and Methods: Thirty-one patients undergoing low-dose screening chest CT were enrolled. Images were reconstructed using filtered back projection (FBP), hybrid iterative reconstruction (HIR), and IMR algorithms. The CT attenuation and image noise for all reconstructions were calculated at the lung apex, middle, and base. Using a 4-point scale, two reviewers visually evaluated the image quality with respect to vessel sharpness, streak artifact, the mediastinum, and the overall image quality of each reconstruction method.
Results: The mean estimated effective dose was 1.00.3 mSv. There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of FBP, HIR, and IMR images was 124.3 +/- 57.3, 34.8 +/- 10.2, and 22.9 +/- 5.8HU, respectively. There were significant differences for all comparison combinations among the three methods (P&lt;0.01). The best subjective overall image quality for the lung and mediastinum was obtained with IMR (P&lt;0.01). The reconstruction time for IMR was within 3min in all cases.
Conclusion: At low-dose chest CT, IMR can improve the qualitative and quantitative visualization of both lung and mediastinal structures especially in the lung apex at a clinically acceptable reconstruction time. Its application may improve diagnostic performance.

DOI： 10.1177/0284185115575537

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Background: The epicardial fat volume (EFV) measured by cardiac CT has emerged as an important parameter for understanding the pathophysiology of coronary atherosclerosis.
Objective: We investigated the variability and reproducibility of EFV measurements and evaluated the effect of model-based type iterative reconstruction (M-IR) on measurement results.
Methods: Non-contrast cardiac CT data (tube voltage 120-kVp, tube current time product 32 mAs) of 30 consecutive patients were reconstructed with filtered back projection (FBP), hybrid type iterative reconstruction (H-IR), and M-IR using a slice thickness of 3.0 mm. CT attenuation and image noise was measured for all reconstructions. Two observers independently quantified EFV using semi-automated software and interobserver agreement was evaluated.
Results: There was no significant difference in the CT attenuation of the ascending aorta among the three reconstructions. The mean image noise on FBP-, H-IR-, and M-IR images was 48.0 +/- 7.9 HU, 29.6 +/- 4.8 HU, and 9.3 +/- 1.3 HU, respectively; there was a significant difference among all comparison combinations for the three reconstructions (p &lt; 0.01). FBP yielded the highest EFV among the three reconstructions (171.0 +/- 54.9 cm(3) [FBP], 153.8 +/- 53.1 cm(3) [H-IR], and 134.0 +/- 46.4 cm(3) [M-IR]). For all three reconstructions, interobserver correlations were excellent (r = 0.91 [FBP], 0.93 [H-IR], and 0.96 [M-IR]). Interobserver comparisons showed that the lowest Blande-Altman limit of agreement was with M-IR (mean difference 2.0 +/- 4.9%, 95% limit of agreement, -24.0 to 28.0%) followed by H-IR (-2.6 +/- 7.1%, -39.8 to 34.6%) and FBP (-0.2 +/- 8.6%, -45.3- to 45.0%).
Conclusion: For the quantification of epicardial fat by cardiac CT, model-based iterative reconstruction can improve the image quality and lessen measurement variability. (C) 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcct.2015.10.006

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: The characterization of plaques based on their computed tomography (CT) number is important for the detection of vulnerable atherosclerotic plaques. An earlier in vitro study showed that intravascular attenuation affected the attenuation of coronary atherosclerotic plaques. We attempted to validate this finding in vivo and here we introduce a dual-phase coronary CT angiography (CCTA) technique to address this issue.
Materials and Methods: Institutional ethics committee approval and informed consent were obtained. Thirty patients (30 noncalcified plaques) underwent dual-phase CCTA. Two CT datasets were obtained, one with coronary artery enhancement and the other without coronary artery enhancement. The CT number of the plaque and the adjacent vessel lumen was measured in a circular region of interest on curved planar reconstruction images. The region of interest setting was consistent between the two CT datasets. We performed linear regression analysis of the changes in the CT numbers (Delta Hounsfield unit), calculated by subtracting the two CT datasets, for the lumen and for the plaque. We also evaluated the relationship between plaque attenuation on nonenhanced coronary artery images and luminal attenuation with and without contrast enhancement.
Results: The Delta Hounsfield unit for the plaque and the lumen showed a strong correlation (r = 0.61). There was no significant correlation between plaque attenuation on nonenhanced coronary artery images and luminal attenuation with and without contrast enhancement (r = 0.23 and 0.24, respectively).
Conclusions: Intravascular attenuation changed the attenuation of coronary atherosclerotic plaques. Using the copy-paste technique, the CT number of identical plaques can be measured in registered dual-phase CCTA images for the evaluation of coronary plaques.

DOI： 10.1016/j.acra.2015.11.003

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.acra.2015.03.009

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC NEURORADIOLOGY  

BACKGROUND AND PURPOSE: Because the diagnostic significance of cortical superficial siderosis for Alzheimer disease and the association between cortical superficial siderosis and the topographic distribution of cerebral microbleeds have been unclear, we investigated the association between cortical superficial siderosis and clinicoradiologic characteristics of patients with cognitive impairment.
MATERIALS AND METHODS: We studied 347 patients (217 women, 130 men; mean age, 74 9 years) who visited our memory clinic and underwent MR imaging (3T SWI). We analyzed the association between cortical superficial siderosis and the topographic distribution of cerebral microbleeds plus clinical characteristics including types of dementia. We used multivariate logistic regression analysis to determine the diagnostic significance of cortical superficial siderosis for Alzheimer disease.
RESULTS: Twelve patients (3.5%) manifested cortical superficial siderosis. They were older (P = .026) and had strictly lobar cerebral microbleeds significantly more often than did patients without cortical superficial siderosis (50.0% versus 19.4%, P = .02); the occurrence of strictly deep and mixed cerebral microbleeds, however, did not differ in the 2 groups. Alzheimer disease was diagnosed in 162 (46.7%) patients. Of these, 8 patients (4.9%) had cortical superficial siderosis. In the multivariate logistic regression analysis for the diagnosis of Alzheimer disease, lacunar infarcts were negatively and independently associated with Alzheimer disease (P = .007).
CONCLUSIONS: Although cortical superficial siderosis was associated with a strictly lobar cerebral microbleed location, it was not independently associated with Alzheimer disease in a memory clinic setting. Additional studies are required to investigate the temporal changes of these cerebral amyloid angiopathy-related MR imaging findings.

DOI： 10.3174/ajnr.A4496

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To assess the optimal reconstruction phase and the image quality of coronary computed tomographic angiography (CCTA) in patients with atrial fibrillation (AF).
We performed CCTA in 60 patients with AF and 60 controls with sinus rhythm. The images were reconstructed in multiple phases in all parts of the cardiac cycle, and the optimal reconstruction phase with the fewest motion artefacts was identified. The coronary artery segments were visually evaluated to investigate their assessability.
In 46 (76.7 %) patients, the optimal reconstruction phase was end-diastole, whereas in 6 (10.0 %) patients it was end-systole or mid-diastole, and in 2 (3.3 %) patients it was another cardiac phase. In 53 (88.3 %) of the controls, the optimal reconstruction phase was mid-diastole, whereas it was end-systole in 4 (6.7 %), and in 3 (5.0 %) it was another cardiac phase. There was a significant difference between patients with AF and the controls in the optimal phase (p &lt; 0.01) but not in the visual image quality score (p = 0.06).
The optimal reconstruction phase in most patients with AF was the end-diastolic phase. The end-systolic phase tended to be optimal in AF patients with higher average heart rates.
aEuro cent The optimal reconstruction phase in 76.7 % of patients with atrial fibrillation (AF) was end-diastole.
aEuro cent The end-systolic phase was optimal in AF patients with higher heart rates.
aEuro cent ECG and heart-rate control are necessary to obtain end-diastolic images with fewer motion artefacts.

DOI： 10.1007/s00330-015-3822-0

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: We used pediatric and adult anthropomorphic phantoms to compare the radiation dose of low- and standard tube voltage chest and abdominal non-contrast-enhanced computed tomography (CT) scans. We also discuss the optimal low tube voltage for non-contrast-enhanced CT.
Methods: Using a female adult- and three differently-sized pediatric anthropomorphic phantoms we acquired chest and abdominal non-contrast-enhanced scans on a 320-multidetector CT volume scanner. The tube voltage was set at 80-, 100-, and 120 kVp. The tube current was automatically assigned on the CT scanner in response to the set image noise level. On each phantom and at each tube voltage we measured the surface and center dose using high-sensitivity metal-oxide-semiconductor field-effect transistor detectors.
Results: The mean surface dose of chest and abdominal CT scans in 5-year olds was 4.4 and 5.3 mGy at 80 kVp, 4.5 and 5.4 mGy at 100 kV, and 4.0 and 5.0 mGy at 120 kVp, respectively. These values were similar in our 3-pediatric phantoms (p &gt; 0.05). The mean surface dose in the adult phantom increased from 14.7 to 19.4 mGy for chest- and from 18.7 to 24.8 mGy for abdominal CT as the tube voltage decreased from 120 to 80 kVp (p &lt; 0.01).
Conclusion: Compared to adults, the surface and center dose for pediatric patients is almost the same despite a decrease in the tube voltage and the low tube voltage technique can be used for non-contrast-enhanced chest- and abdominal scanning. (C) 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2015.12.005

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Size-specific dose estimate (SSDE) takes into account the patient size but remains to be fully validated for adult coronary computed tomography angiography (CCTA). We investigated the appropriateness of SSDE for accurate estimation of patient dose by comparing the SSDE and the volume CT dose index (CTDIvol) in adult CCTA. This prospective study received institutional review board approval, and informed consent was obtained from each patient. We enrolled 37 adults who underwent CCTA with a 320-row CT. High-sensitivity metal oxide semiconductor field effect transistor dosimeters were placed on the anterior chest. CTDIvol reported by the scanner based on a 32-cm phantom was recorded. We measured chest diameter to convert CTDIvol to SSDE. Using linear regression, we then correlated SSDE with the mean measured skin dose. We also performed linear regression analyses between the skin dose/CTDIvol and the body mass index (BMI), and the skin dose/SSDE and BMI. There was a strong linear correlation (r = 0.93, P &lt; 0.001) between SSDE (mean 37 +/- A 22 mGy) and mean skin dose (mean 17.7 +/- A 10 mGy). There was a moderate negative correlation between the skin dose/CTDIvol and BMI (r = 0.45, P &lt; 0.01). The skin dose/SSDE was not affected by BMI (r = 0.06, P &gt; 0.76). SSDE yields a more accurate estimation of the radiation dose without estimation errors attributable to the body size of adult patients undergoing CCTA.

DOI： 10.1007/s10554-015-0782-z

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: To investigate differences in image-to-image variations between full- and half-scan reconstruction on myocardial CT perfusion (CTP) study.
Methods: Using a cardiac phantom we performed ECG-gated myocardial CTP on a second-generation 320-multidetector CT volume scanner. The heart rate was set at 60 bpm; once per second for a total of 24 s were performed. CT images were acquired at 80- and 120 kVp and subjected to full-and half-scan reconstruction. On images acquired at the same slice level we then measured image-to-image variations, coefficients of variance (CV), and image noise.
Results: The image-to-image variations with full-and half-scan reconstruction were 1.3 HU vs. 27.2 HU at 80 kVp (p &lt; 0.001) and 0.70 HU vs. 9.3 HU at 120 kVp (p &lt; 0.001) even though the mean HU value was almost the same for both reconstruction methods. The CV of 80- and 120-kVp images of the left ventricular cavity decreased by 0.16% and 0.17%, respectively, with full-scan reconstruction; with half-scan reconstruction it decreased by 3.34% and 2.30%, respectively. Compared with half-scan reconstruction, the image noise was reduced by 27.2% at 80 kVp and by 28.0% at 120 kVp with full-scan reconstruction.
Conclusion: Myocardial CTP with full-scan reconstruction substantially decreased image-to-image variations and provided accurate CT attenuation. (C) 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2015.05.018

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SAGE PUBLICATIONS LTD  

Background: The 256-slice computed tomography (CT) scanners with wider detector coverage and faster gantry rotation speed are now available. The performance of scanners that feature a rotation speed of 270 ms at coronary CT angiography (CCTA) has not been evaluated in patients with a higher heart rate.
Purpose: To evaluate the image quality of 256-slice CT with faster gantry rotation speed in patients undergoing CCTA.
Material and Methods: We enrolled 886 patients; 357(40.3%) underwent study on a 64-slice CT at a rotation speed of 420 ms, the other 529 (59.7%) were examined using a 256-slice CT scanner at 270 ms. Two observers judged the image quality of 2658 imaged coronary arteries on a 4-point scale.
Results: The mean image quality score was significantly higher for the 256 - than the 64-slice CT scans (3.94 +/- 0.28 vs. 3.73 +/- 0.61; P &lt; 0.01). There was no significant difference in the image quality scores between 64- and 256-slice scans in patients whose heart rate (HR) was &lt;60 bpm. However, in patients whose HR exceeded 60 bpm these scores were significantly higher for 256-slice CT images (P&lt;0.01).
Conclusion: CCTA performed on the 256-slice CT scanner yielded significantly better image quality in patients with an HR exceeding 60 bpm.

DOI： 10.1177/0284185114555152

Web of Science

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1177/0284185115590285

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SAGE PUBLICATIONS LTD  

Background: Body weight, body mass index (BMI), and scout X-ray radiographic attenuation can be used to predict image noise on computed tomographic coronary angiography (CTCA) images.
Purpose: To use a formula to predict patient-specific image noise and then select an appropriate CTCA patient-specific tube voltage for better radiation control.
Material and Methods: Forty-eight patients who underwent CTCA imaging at 120kVp were reviewed, and their patient information and scouting X-ray radiographic attenuations were recorded to identify the best correlations between patient data and image noise and to develop a predicted image noise formula. Subsequently, 54 patients subjected to scanning at 100 or 120kVp, depending on the noise predicted by our formula, were prospectively studied. Two radiologists visually assessed the image quality of the right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX) by consensus readings.
Results: The predicted image noise=0.939 BMI+0.025 scouting attenuation+20.16. The median value of the overall image noise was 30.55HU at 120kVp and 29.85HU at 100kVp. The mean visual evaluation scores at 100 and 120kVp were 3.25 and 3.24 for the proximal RCA, 3.40 and 3.26 for the proximal LAD, and 3.30 and 3.15 for the proximal LCX, respectively.
Conclusion: The BMI and scouting X-ray radiographic attenuation can be combined to predict the CTCA image noise. Our prediction formula is useful for deciding when to switch from the 120- to the 100-kVp technique.

DOI： 10.1177/0284185114549826

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The purpose of our study was to investigate the added value of the single-energy projection-based metallic artifact reduction (SEMAR) technique on the visualization and diagnostic confidence of oral cavity cancers.
Contrast-enhanced CT was performed on 40 patients with dental metalwork. Of these, 18 patients had pathologically confirmed oral cavity cancer, and the other 22 patients had no lesions. CT attenuation and noise in the oral cavity were compared between the conventional and SEMAR images. Two radiologists visually graded the diagnostic confidence on a 5-point scale from 1 (definitely absent) to 5 (definitely present). The value of the SEMAR was assessed in a receiver-operating characteristic curve analysis.
The artifact of the SEMAR images was significantly lower than that of the conventional images (38.4 +/- A 18.0 HU vs. 187.7 +/- A 162.7 HU; P &lt; 0.01). Reviewers 1 and 2 detected 10 and 7 more lesions with the SEMAR, respectively. Areas under the curve for the conventional and SEMAR reconstruction were 0.761 and 0.942, respectively, for reviewer 1 and 0.701 and 0.864, respectively, for reviewer 2.
The SEMAR significantly improved the oral cavity cancer visualization and diagnostic confidence.

DOI： 10.1007/s11604-015-0471-9

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Purpose
To determine the minimum apparent diffusion coefficient (ADC(min)) values of benign and malignant hepatic lesions based on diffusion-weighted imaging and to compare the diagnostic performance of ADC(min) and mean ADC (ADC(mean)) values for differentiating between benign and malignant tumors of the liver.
Materials and Methods
We retrospectively subjected 240 patients with 195 malignant (hepatocellular carcinoma [HCC], n = 137; metastases, n = 44; cholangiocellular carcinoma [CCC], n = 14) and 45 benign tumors (hemangiomas, n = 37; focal nodular hyperplasia [FNH], n = 8). Both ADC(mean) and ADC(min) were evaluated independently by 2 readers, the sensitivity and specificity for the detection of malignancy were calculated, and receiver operating characteristic (ROC) curves were generated. To determine interobserver agreement, we calculated the Pearson correlation coefficient.
Results
Mean ADC (x10(-3) mm(2)/s) was 1.19 for malignant (HCC, 1.15; metastasis, 1.23; CCC, 1.51) and 2.01 for benign tumors (hemangioma, 2.09; FNH, 1.52; P &lt; 0.001). Minimum ADC was 0.81 for malignant (HCC, 0.79; metastasis, 0.81; CCC, 0.91) and 1.62 for benign tumors (hemangioma, 1.66; FNH, 1.28; P &lt; 0.001). The sensitivity, specificity, and the calculated area under the ROC curve for diagnosing malignant lesions were 86.2%, 86.7%, and 0.942 (reader 1) and 88.7%, 88.9%, and 0.939 (reader 2) for ADC(mean); they were of 92.3%, 97.8%, and 0.984 (reader 1) and 94.9%, 97.8%, and 0.983 (reader 2) for ADC(min).
Conclusions
Mean ADC and ADC(min) were valuable for differentiating between malignant and benign hepatic lesions. The area under the ROC curve of ADC(min) was significant higher than that of ADC(mean).

DOI： 10.1097/RCT.0000000000000228

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To compare conventional CT angiography (CTA) and CTA reconstructed from CT perfusion source data (perfusion CTA) acquired on a 320-section CT scanner for the evaluation of intracranial arteries.
Our study included 7 patients who had undergone trapping of an intracranial aneurysm and placement of a bypass. All underwent conventional and perfusion CTA and digital subtraction angiography (DSA). Using DSA as the gold standard, 2 radiologists evaluated 10 arterial segments on conventional and perfusion CTA images. On a 4-point scale they independently scored the image quality and vascular visualization of the intracranial arteries on the conventional and perfusion CTA images. The effective radiation dose to each patient was also recorded.
A total of 65 arterial segments without apparent abnormalities were assessed. While the mean image quality score tended to be slightly higher for conventional than perfusion CTA, there was no significant difference. The effective dose for perfusion and conventional CTA with unenhanced CT was 4.2 mSv and 3.1 mSv, respectively, for all patients.
For the evaluation of intracranial arteries using DSA as the gold standard, perfusion CTA yields image quality and vascular visualization similar to conventional CTA at an acceptable radiation dose.

DOI： 10.1007/s11604-015-0429-y

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPANESE CIRCULATION SOC  

Background: Myocardial perfusion imaging (MPI) may fail to detect balanced ischemia. We evaluated myocardial perfusion reserve (MPR) using Tl dynamic single-photon emission computed tomography (SPECT) and a novel cadmium zinc telluride (CZT) camera for predicting 3-vessel or left main coronary artery disease (CAD).
Methods and Results: A total of 55 consecutive patients with suspected CAD underwent SPECT-MPI and coronary angiography. The MPR index was calculated using the standard 2-compartment kinetic model. We analyzed the utility of MPR index, other SPECT findings, and various clinical variables. On multivariate analysis, MPR index and history of previous myocardial infarction (MI) predicted left main and 3-vessel disease. The area under the receiver operating characteristic curve was 0.81 for MPR index, 0.699 for history of previous MI, and 0.86 for MPR index plus history of previous MI. MPR index &lt;= 1.5 yielded the highest diagnostic accuracy. Sensitivity, specificity, and accuracy were 86%, 78%, and 80%, respectively, for MPR index, 64%, 76%, 73% for previous MI, and 57%, 93%, and 84% for MPR index plus history of previous MI.
Conclusions: Quantification of MPR using dynamic SPECT and a novel CZT camera may identify balanced ischemia in patients with left main or 3-vessel disease.

DOI： 10.1253/circj.CJ-14-0932

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER INTERNATIONAL PUBLISHING AG  

The influence of newer-generation CT on the clinical indications and appropriateness of cardiac CT has not been adequately surveyed. We aimed to evaluate the distribution of appropriateness ratings and test the outcomes of cardiac CT using second-generation 320-row CT. The 2010 appropriate use criteria (AUC) were applied at the point of service to a consecutive series of patients (N = 309) who were referred for cardiac CT. The CT indication was determined based on interviews and medical records. The proportions of patients within the categories of appropriate (A), uncertain (U), inappropriate (I), and not covered were described. The prevalence of significant coronary artery disease (CAD) was also compared among the categories. The proportions were 49.2%, 25.9%, and 20.7% for appropriate, uncertain, and inappropriate indication, respectively. The indication that was not covered was only 4.2%. Significant CAD was more frequently observed for uncertain-than appropriate indication (42.5% vs 27.6%; P = 0.03), although the number of significant stenosed segments was not different (P = 0.13). The recent advancement of cardiac CT increased the proportion of uncertain scans, which were associated with a high prevalence of significant CAD.

DOI： 10.1186/s40064-015-0866-1

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: To investigate whether a newly-developed single-energy metal artifact reduction (SEMAR) algorithm applied to images acquired on a 320-MDCT volume scanner reduces image artifacts from dental metal.
Methods: We inserted the lower right teeth covered with a dental metal alloy and crown in a skull phantom and performed single-volume scanning on a second-generation 320-MDCT scanner. A 12-mm diameter spherical lesion was placed either close to or far from the dental metal. The tube voltage and current were 120 kVp and 80 or 155 mA, respectively. Images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR), with or without SEMAR. We calculated the signal-to-artifact ratios (SAR) to quantify the visibility of the lesion. Two radiologists inspected 96 images (48 with lesion and 48 without) for the presence or absence of the lesion using a 5-point ordinal scale (1 = definitely absent to 5 = definitely present).
Results: On images reconstructed with FPB and IR with SEMAR, streak artifacts from the dental metal were reduced substantially compared to images without SEMAR. At 155 mA with the lesion near the dental metal, the SARs were better on FBP and IR images (FBP: 1.7 and 0.5 with and without SEMAR, respectively; IR: 1.6 and 0.9 with and without SEMAR, respectively). The observer visual scores improved with SEMAR (FBP: 4.2 and 3.2 with and without SEMAR, respectively; IR: 4.2 and 3.0).
Conclusion: The SEMAR algorithm reduces dental metal artifacts and improves lesion detectability and image quality in patients with oral cavity lesions. (C) 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2014.10.003

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: Subtraction coronary computed tomography (CT) angiography (CCTA), which enables the removal of calcium and coronary stents from CCTA images, has been clinically introduced on a second-generation 320-row CT scanner. However, this technique for clinical use is not optimized. The long breath-holding time for two data acquisitions, which causes image misregistration and patient's discomfort, may limit the clinical availability of this subtraction technique.
Materials and Methods: This study received approval from the institutional review board; prior informed consent to participate was obtained from all patients. We performed subtraction CCTA of five patients using the test injection method and optimized the interval time between the first (pulmonary-arterial phase) and the second (coronary-arterial phase) scans to achieve robust subtraction. The patients' breath-holding times were recorded. We compared breath-holding times between our new protocol and previous study's protocol (estimated).
Results: Mean breath-holding time in our new protocol was 18.3 +/- 3.4 seconds and that in previous protocol was 29.8 +/- 3.6 seconds (difference in mean breath-holding time was 11.5 seconds). Misregistration artifacts were not shown in final subtraction CCTA images. These images improved luminal visualization in the calcified lesion.
Conclusions: Our test injection protocol can shorten the breath-holding time, which is helpful for successful subtraction CCTA imaging, potentially resulting in an increase of subtraction CCTA examinations in many institutions.

DOI： 10.1016/j.acra.2014.09.020

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Background: Among CT scanners, 320-row instruments feature decreased photon energy and yield strong contrast enhancement. Consequently, the contrast medium (CM) dose can be reduced. The results of low-tube-voltage coronary CT angiography (CCTA) performed on 30-row scanners have not been adequately assessed.
Objective: We evaluated the effects of a low-contrast-dose protocol on the image quality of CCTA using 80 kVp tube voltage, iterative reconstruction (IR), and a 320-row scanner.
Methods: We randomly assigned 90 patients (mean body weight, 56.5 +/- 11.0 kg) to 1 of 3 CCTA protocols. Under protocol A, 30 were scanned using a conventional 120-kVp protocol and a standard CM dose (2.80 mg iodine/kg body weight mgI/kg]). Another 30 underwent scanning at 80 kVp with a 25% CM dose reduction (210 mgI/kg; protocol B). Under protocol C, the remaining 30 patients were scanned at 80 kVp with a 50% CM dose reduction (140 mgI/kg). The 120 and 80 kVp images were processed with IR. Images obtained under the 3 protocols were subjected to quantitative and qualitative analysis.
Results: The amount of CM used in protocol A, B, and C was 43.6 +/- 10.1, 30.3 +/- 4.4, and 21.0 +/- 4.0 mL, respectively. Mean CT attenuation of the coronary arteries tended to be higher under protocol B than the other 2 protocols. The contrast-to-noise ratio was significantly higher under protocol B. The mean visual scores were significantly higher for protocols A and B than protocol C. The mean effective radiation dose was significantly lower under the 80-kVp protocol.
Conclusion: With a 320-row scanner and our refined CM injection and timing protocol, it is technically feasible to obtain sufficient vascular enhancement with a reduction in the CM and/or radiation dose at 80-kVp CCTA with IR. (C) 2015 Society of Cardiovascular Computed Tomography. All rights reserved.

DOI： 10.1016/j.jcct.2014.12.002

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MULTIMED INC  

We performed retrospective (first-step) and prospective (second-step) studies to evaluate the body information and noise on temporal bone computed tomography (CT) images in efforts to identify the optimized tube current yielding the greatest reduction in the radiation exposure of pediatric patients undergoing temporal bone CT studies. Our first-step study included 90 patients subjected to temporal bone CT. We recorded displayed volume CT dose index (CTDIvol), displayed dose-length product (DLP), image noise, and the patient age and sex. We then calculated the optimized tube current value with and without IR corresponding to the children's age based on the ratio of the noise on images from individuals older than 18 years. In our second-step study, we enrolled 23 pediatric patients and obtained CT scans using our optimized protocol. In both studies we applied identical analysis techniques. The diagnostic image quality was confirmed reading reports and a neuroradiologist. Our first-step study indicated that the mean image noise in children assigned to five ascending age groups from 2 to 12 years ranged from 167.59 to 211.44 Hounsfield units (HU). In the second-step study, the mean image noise in each age group was almost the same as the expected noise value and the diagnostic image quality was acceptable. The dose reduction was ranged from 57.5% to 37.5%. Optimization of the tube current-time product allows a radiation reduction without a loss in image quality in pediatric patients undergoing temporal bone CT.

DOI： 10.1120/jacmp.v16i1.5082

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Background The liver itself regenerates after hepatectomy but little is known about how much hepatic function recovers during the regeneration. The liver uptake value (LUV), calculated from Tc-99m-labeled galactosyl-human-serumalbumin (Tc-99m-GSA) SPECT/CT fused images, is reliable and useful for evaluating hepatic function. In this study, we evaluated the clinical usefulness of LUV for estimating hepatic functional regeneration after hepatectomy.
Methods We enrolled 95 patients who had undergone Tc-99m-GSA SPECT/CT tests before/on days 30 and 90 after hepatectomy. We determined the LUV from the (99m)TcGSA SPECT/CT images and calculated the %LUV (postoperative LUV/preoperative LUV x 100). Based on surgical procedures and histopathological damage, we divided the study population into patients with severe (n = 12) or non-severe fibrosis (n = 33) who had undergone minor hepatectomy, and patients with severe (n = 14) or non-severe fibrosis (n = 36) having major hepatectomy. On the 90th post-hepatectomy day, five patients manifested liver failure; in these patients, we analyzed the co-relation between liver failure and the results of the liver function tests performed on day 30 after surgery.
Results Although the %LUV reached 95.4 +/- 12.2 % in 30 days, in patients with severe fibrosis after major hepatectomy it remained below 90 %. Patients having low %LUV (&lt;75 %) and high serum bilirubin (&gt;2.0 mg/dl) at 30 days showed a relative risk of liver failure of 12.0 and 4.5 (p&lt;0.001 and p&lt;0.001), respectively.
Conclusions Although the % LUV recovered to about 95 % in all patients within 30 days after the hepatectomy, in patients with severe fibrosis having major hepatectomy, the process of recovery was delayed. The %LUV corresponded to the quality of the liver function which emerged in a later post-hepatectomy phase.

DOI： 10.1007/s12149-014-0872-3

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: To compare the noise and accuracy on images of the whole porcine liver acquired with iterative reconstruction (IMR, Philips Healthcare, Cleveland, OH, USA) and filtered back projection (FBP) methods. Materials and methods: We used non-enhanced porcine liver to simulate the human liver and acquired it 100 times to obtain the average FBP value as the ground-truth. The mean and the standard deviation ("inter-scan SD") of the pixel values on the 100 image acquisitions were calculated for FBP and for three levels of IMR (L1, L2, and L3). We also calculated the noise power spectrum (NPS) and the normalized NPS for the 100 image acquisitions.
Results: The spatial SD for the porcine liver parenchyma on these slices was 9.92, 4.37, 3.63, and 2.30 Hounsfield units with FBP, IMR-L1, IMR-L2, and IMR-L3, respectively. The detectability of small faint features was better on single IMR than single FBP images. The inter-scan SD value for IMR-L3 images was 53% larger at the liver edges than at the liver parenchyma; it was only 10% larger on FBP images. Assessment of the normalized NPS showed that the noise on IMR images was comprised primarily of low-frequency components.
Conclusion: IMR images yield the same structure informations as FBP images and image accuracy is maintained. On level 3 IMR images the image noise is more strongly suppressed than on IMR images of the other levels and on FBP images. (C) 2014 Published by Elsevier Ltd on behalf of Associazione Italiana di Fisica Medica.

DOI： 10.1016/j.ejmp.2014.02.005

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: To investigate whether electrocardiogram (ECG)-gated single- and dual-heartbeat computed tomography coronary angiography (CTCA) with automatic exposure control (AEC) yields images with uniform image noise at reduced radiation doses.
Materials and methods: Using an anthropomorphic chest CT phantom we performed prospectively ECG-gated single- and dual- heartbeat CTCA on a second-generation 320-multidetector CT volume scanner. The exposure phase window was set at 75%, 70-80%, 40-80%, and 0-100% and the heart rate at 60 or 80 or corr80 bpm; images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR, adaptive iterative dose reduction 3D). We applied AEC and set the image noise level to 20 or 25 HU. For each technique we determined the image noise and the radiation dose to the phantom center.
Results: With half-scan reconstruction at 60 bpm, a 70-80% phase window- and a 20- HU standard deviation (SD) setting, the imagenoise level and -variation along the z axis manifested similar curves with FBP and IR. With half-scan reconstruction, the radiation dose to the phantom center with 70-80% phase window was 18.89 and 12.34 mGy for FBP and 4.61 and 3.10 mGy for IR at an SD setting SD of 20 and 25 HU, respectively. At 80 bpm with two-segment reconstruction the dose was approximately twice that of 60 bpm at both SD settings. However, increasing radiation dose at corr80 bpm was suppressed to 1.39 times compared to 60 bpm.
Conclusion: AEC at ECG-gated single- and dual-heartbeat CTCA controls the image noise at different radiation dose. (C) 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2013.10.003

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC  

Persistently high cardiac troponin T (cTnT) levels reflect myocardial damage in heart failure (HF). The presence and extent of myocardial fibrosis assessed by cardiac magnetic resonance (CMR) and high levels of cTnT predict poor prognosis in various cardiomyopathies. However, the association between myocardial fibrosis and transcardiac cTnT release has not been evaluated. This study investigated-the correlation between myocardial fibrosis and transcardiac cTnT release from nonischemic failing myocardium. Serum cTnT levels were measured in aortic root (Ao) and coronary sinus (CS) using highly sensitive assay (detection limit &gt;5 ng/L) in 74 nonischemic patients with HP who underwent CMR. Transcardiac cTnT release (Delta cTnT [CS-Ao]) represented the difference between CS and Ao-cTnT levels. Myocardial fibrosis was quantified by late gadolinium enhancement (LGE) volume and %LGE on CMR. cTnT was detectable in 65 patients (88%), and Delta cTnT (CS-Ao) levels were available (Delta cTnT [CS-Ao] &gt;0 ng/L) in 60 patients (81%). LGE was observed in 42 patients (57%), and Delta cTnT (CS-Ao) levels were available in 41 LGE-positive patients (98%). In patients with available cTnT release, Delta cTnT (CS-Ao) levels were significantly higher in LGE-positive patients than those in LGEnegative patients (4.3 [2.2-5.51 vs 1.5 [0.9-2.6] ng/L; p = 0.001). Log (Delta cTnT [CS-Ao]) levels were correlated with LGE volume (r = 0.460, p = 0.003) and %LGE (r = 0.356, p = 0.03). In conclusion, the amount of transcardiac cTnT release was higher in LGE-positive patients than LGE-negative patients and correlated with the extent of LGE in nonischemic patients with HF. These results suggested that ongoing myocardial damage correlates with the presence and extent of myocardial fibrosis. (C) 2014 The Authors. Published by Elsevier Inc. All rights reserved.

DOI： 10.1016/j.amjcard.2014.02.029

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The purpose of our study was to evaluate the morphology of the lumbosacral spine, i.e. the dura and vertebral body shape, of Japanese patients with Marfan syndrome (MFS) by comparing it with sex- and age-matched controls.
Spinal MR or CT images of 32 MFS patients and 32 controls were retrospectively reviewed. The anteroposterior dural sac diameter (DSD), anteroposterior vertebral body diameter (VBD), and vertebral body height (VBH) were measured from L1 to S1 levels and the dural sac ratio [DSR = (DSD/VBD)] and vertebral body aspect ratio [VAR = (VBH/VBD)] were calculated.
At each level, mean DSD and DSR were significantly higher in MFS patients; VBD was not. The cutoff values for DSR to differentiate between MFS patients and the controls were 0.59, 0.46, 0.42, 0.45, 0.47, and 0.47 from the level of L1 to S1. At a sensitivity of 93.8 % and a specificity of 84.4 % the cutoff value at S1 was most diagnostic. In MFS patients VAR was significantly higher at L3 and L4.
Our cutoff value for DSR &gt; 0.47 at S1 may help to identify MFS in the Japanese population. A square-like appearance of the L3 and L4 vertebral bodies is a supplementary finding in MFS patients.

DOI： 10.1007/s11604-014-0285-1

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

We developed a new individually customized contrast-injection protocol for coronary computed tomography (CT) angiography based on the time-attenuation response in a test bolus, and investigated its clinical applicability. We scanned 60 patients with suspected coronary diseases using a 64-detector CT scanner, who were randomly assigned to one of two protocols. In protocol 1 (P1), we estimated the contrast dose to yield a peak aortic attenuation of 400 HU based on the time-attenuation response to a small test-bolus injection (0.3 ml/kg body weight) delivered over 9 s. Then we administered a customized contrast dose over 9 s. In protocol 2 (P2), the dose was tailored to the patient's body weight; this group received 0.7 ml/kg body weight with an injection duration of 9 s. We compared the two protocols for dose of contrast medium, peak attenuation, variations in attenuation values of the ascending aorta, and the success rate of adequate attenuation (250-350 HU) of the coronary arteries. The contrast dose was significantly smaller in P1 than in P2 (36.9 +/- 9.2 vs 43.1 +/- 7.0 ml, P &lt; 0.01). Peak aortic attenuation was significantly less under P1 than under P2 (384.1 +/- 25.0 vs 413.5 +/- 45.7, P &lt; 0.01). The mean variation (standard deviation) of the attenuation values was smaller in P1 than in P2 (25.0 vs 45.7, P &lt; 0.01). The success rate of adequate attenuation of the coronary arteries was significantly higher with P1 than with P2 (85.0 vs 65.8 %, P &lt; 0.01). P1 facilitated a reduction in the contrast dose, reduced the individual variations in peak aortic attenuation, and achieved optimal coronary CT attenuation (250-350 HU) more frequently than P2.

DOI： 10.1007/s00380-013-0338-x

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Background: Most current iterative reconstruction algorithms for CT imaging are a mixture of iterative reconstruction and filtered back projection. The value of "fully" iterative reconstruction in coronary CT angiography remains poorly understood. Objective: We aimed to assess the value of the knowledge-based iterative model reconstruction (IMR) algorithm on the qualitative and quantitative image quality at 256-slice cardiac CT.
Methods: We enrolled 21 patients (mean age: 69 +/- 11 years) who underwent retrospectively ECG gated coronary CT anhgiography at 100 kVp tube voltage. Images were reconstructed with the filtered back projection (FBP), hybrid iterative reconstruction (IR), and IMR algorithms. CT attenuation and the contrast-to-noise ratio (CNR) of the coronary arteries were calculated. With the use of a 4-point scale, 2 reviewers visually evaluated the coronary arteries and cardiac structures.
Results: The mean CT attenuation of the proximal coronary arteries was 369.3 +/- 73.6 HU, 363.9 +/- 75.3 HU, and 363.3 +/- 74.5 HU, respectively, for FBP, hybrid IR, and IMR and was not significantly different. The image noise of the proximal coronary arteries was significantly lower with IMR (11.3 +/- 2.8 HU) than FBP (51.9 +/- 12.9 HU) and hybrid IR (23.2 +/- 5.2 HU). The mean CNR of the proximal coronary arteries was 9.4 +/- 2.4, 20.2 +/- 4.7, and 41.8 +/- 9.5 with FBP, hybrid IR and IMR, respectively; it was significantly higher with IMR. The best subjective image quality for coronary vessels was obtained with IMR (proximal vessels: FBP, 2.6 +/- 0.5; hybrid IR, 3.4 +/- 0.5; IMR, 3.8 +/- 0.4; distal vessels: FBP, 2.3 +/- 0.5; hybrid IR. 3.1 +/- 0.5; IMR, 3.7 +/- 0.5). IMR also yielded the best visualization for cardiac systems, that is myocardium and heart valves.
Conclusion: The novel knowledge-based IMR algorithm yields significantly improved CNR and better subjective image quality of coronary vessels and cardiac systems with reliable CT number measurements for cardiac CT imaging. (C) 2014 Society of Cardiovascular Computed Tomography. All rights reserved.

DOI： 10.1016/j.jcct.2013.12.010

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC NEURORADIOLOGY  

BACKGROUND AND PURPOSE: For the localization of spinal dural arteriovenous fistulas, it is not determined whether dynamic contrast-enhanced MRA is more reliable than multidetector CTA. The aim of this study was to compare the agreement between intra-arterial DSA, dynamic contrast-enhanced MRA at 3T, and 64-row multidetector CTA for the localization of spinal dural arteriovenous fistulas.
MATERIALS AND METHODS: We enrolled 12 consecutive patients (11 men, 1 woman; age range, 46-83 years; mean, 65 years) who underwent preoperative dynamic contrast-enhanced MRA at 3T and 64-row multidetector CTA. The spinal dural arteriovenous fistula location was confirmed by intra-arterial DSA as the reference standard. Two reviewers independently evaluated the level of the artery feeding the spinal dural arteriovenous fistula on the basis of continuity between the feeder and abnormal spinal vessels on 3T dynamic contrast-enhanced MRA and 64-row multidetector CTA images. Interobserver and intermodality agreement was determined by calculation of the coefficient.
RESULTS: On DSA, the vessel feeding the spinal dural arteriovenous fistula was the intercostal artery (7 cases), the lumbar artery (3 cases), and the internal iliac artery or the ascending pharyngeal artery (1 case each). For the fistula level, interobserver agreement was excellent for 3T dynamic contrast-enhanced MRA ( = 0.97; 95% CI, 0.92-1.00) and very good for 64-row multidetector CTA ( = 0.84; 95% CI, 0.72-0.96). Intermodality agreement with DSA was good for 3T dynamic contrast-enhanced MRA ( = 0.78; 95% CI, 0.49-1.00) and moderate for 64-row multidetector CTA ( = 0.41; 95% CI, 0.020-0.84).
CONCLUSIONS: For the localization of spinal dural arteriovenous fistulas, 3T dynamic contrast-enhanced MRA may be more reliable than 64-row multidetector CTA.

DOI： 10.3174/ajnr.A3660

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: To investigate whether "full" iterative reconstruction, a knowledge-based iterative model reconstruction (IMR), enables radiation dose reduction by 80% at cardiac computed tomography (CT).
Materials and Methods: A total of 23 patients (15 men, eight women; mean age 64.3 +/- 13.4 years) who underwent retrospectively electrocardiography-gated cardiac CT with-dose modulation were evaluated. We compared full-dose (FD; 730 mAs)images reconstructed with filtered back projection (FBP) technique and the low-dose (LD; 146 mAs) images reconstructed with FBP and IMR techniques. Objective and subjective image quality parameters were compared among the three different CT images.
Results: There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of LD-IMR (18.3 +/- 10.6 Hounsfield units [HU]) was significantly lowest among the three reconstructions.(41.9 +/- 15.3 HU for FD-FBP and 109.9 +/- 42.6 HU for LD-FBP; P &lt;.01). The contrast-to-noise ratio of LD-IMR was better than that of FD-FBP and LD-FBP (P &lt;.01). Visual evaluation score was also highest for LD-IMR.
Conclusions: The IMR can provide improved image quality at super-low-dose cardiac CT with 20% of the standard-tube current.

DOI： 10.1016/j.acra.2013.10.002

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objective
The aim of this study was to evaluate the effect of a low tube voltage technique and hybrid iterative reconstruction (HIR) on image quality at 3-dimensional computed tomographic angiography (3D-CTA) of the liver.
Methods
Before hepatic surgery, we randomly assigned 60 patients (17 women, 43 men; mean +/- SD age, 68.9 +/- 10.1 years) who had undergone 3D-CTA to 1 of 2 protocols; 30 patients underwent scanning under the conventional 120-kilovolt (peak) protocol with filtered back projection (P1); and 30 patients, under an 80-kilovolt (peak) protocol with HIR (P2). The estimated effective radiation dose, computed tomographic attenuation, image noise, contrast-to-noise ratio, and figure of merit were calculated, and the visual image quality of 3D-CTA was scored on a 4-point scale.
Results
The mean effective radiation dose was significantly lower under P2 than P1 (4.8 +/- 1.2 vs 7.2 +/- 1.5 mSv, P &lt; 0.01). P1 and P2 did not significantly differ with respect to the image noise (10.5 +/- 2.3 vs 9.9 +/- 1.6 Hounsfield units; P = 0.46). Computed tomographic attenuation, contrast-to-noise ratio, figure of merit, and the visual scores for image quality were higher under P2 than P1 (P &lt; 0.01).
Conclusions
The use of low tube voltage and HIR can yield significantly improved image quality at 3D-CTA of the liver.

DOI： 10.1097/RCT.0b013e3182a9a518

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER IRELAND LTD  

Background: Myocardial bridging is a common finding on multi-detector computed tomography (MDCT). The segment proximal to a myocardial bridge is frequently atherosclerotic, although the tunneled segment is spared. This study aimed to investigate whether myocardial bridging identified by MDCT is an independent risk factor for coronary atherosclerosis.
Methods and results: Patients (n = 188) with suspected coronary disease underwent MDCT using a 40-detector or 64-detector instrument. We reviewed the baseline characteristics (age, body mass index, smoking history, presence of hypertension, dyslipidemia, and diabetes mellitus) and the results of MDCT angiography. Two radiologists evaluated the coronary artery for myocardial bridging and coronary atherosclerosis and made a diagnosis by consensus. Significant independent risk factors for coronary atherosclerosis were investigated by multivariate logistic regression analysis. We identified 50 bridges in the middle segment of the left anterior descending artery (LAD). There were no patients with significant stenosis in the tunneled segment. Multivariate analysis showed that age, diabetes mellitus, and myocardial bridging in the mid-LAD were significantly associated with coronary atherosclerosis in the proximal LAD (p &lt; 0.05). Age, diabetes mellitus, and the absence of myocardial bridging in the mid-LAD were significantly associated with coronary atherosclerosis in the mid-LAD (p &lt; 0.05).
Conclusion: The segment proximal to a segment with myocardial bridging is frequently involved in atherosclerosis, although the tunneled segment is spared. Myocardial bridging in the mid-LAD is an independent risk factor for coronary atherosclerosis in the proximal LAD. (C) 2013 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.

DOI： 10.1016/j.jjcc.2013.07.005

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Kurume University School of Medicine  

Sufficient colonic dilation is important when using CT colonography (CTC) for colorectal cancer screening. We investigated the effect of antispasmodic agents and the patient body habitus on the degree of colonic dilation in screening CTC. We assessed the effect of clinical characteristics [age, gender, body mass index (BMI), and the presence of diverticula] and the use of antispasmodics on colonic distention in 140 patients who underwent CTC for colorectal cancer screening. The CTC was performed in both the supine- and prone positions. Seventy patients received antispasmodics prior to CT examination and the other 70 did not. Colonic distention was scored using a 5-point scale: 1=collapsed, 2=poorly visualized, 3=visualized but underdistended, 4=acceptable, and 5=excellent. Images scored as 4 or 5 were considered to be of diagnostic quality. The mean visual evaluation score was significantly higher in the supine- than the prone position (4.2±0.5 vs. 4.0±0.5, p&lt
0.01). For the supine position, only the use of antispasmodic was statistically associated with sufficient colonic dilation by univariate logistic analysis (odds ratio=2.365, p=0.03). For the prone position, age, BMI, and the use of antispasmodic were statistically associated with sufficient colonic dilation by multivariate analysis. The odds ratio of these parameters was 0.955 (p=0.02), 0.874 (p=0.03), and 2.391 (p=0.02), respectively. We obtained sufficient colonic dilation with an antispasmodic for CTC in both positions. Younger age and a lower BMI were also associated with better colonic dilation in the prone position.

DOI： 10.2739/kurumemedj.MS64002

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JPN SOC MAGNETIC RESONANCE IN MEDICINE  

Purpose: Differences in acute adverse reactions to different gadolinium (Gd)-based contrast agents have not been thoroughly evaluated. We investigated the relationships among the incidence and severity of acute adverse reactions, backgrounds of patients, and 4 types of different Gd-based contrast agents (gadopentetate dimeglumine, gadoteridol, gadoterate meglumine, and gadoxetate disodium).
Materials and Methods: We retrospectively reviewed the radiological records of 10,595 consecutive patients (4,343 female; 6,252 male; mean age, 63.8 +/- 14.0 years) who underwent contrast-enhanced magnetic resonance imaging between August 2006 and March 2011. Adverse reactions were classified as mild, moderate, and severe according to the definition of the American College of Radiology. The incidence of adverse reactions were compared on the basis of clinical characteristics and type, dose, and delivery methods of contrast agents by univariate and multivariate logistic regression analyses.
Results: The incidence of overall reactions was 0.45% (48/10,595); 45 reactions were mild and three were moderate. No severe reactions were observed. Although the incidence of adverse reactions did not differ significantly between male and female patients, younger individuals were at higher risk for acute adverse reactions. The contrast injection rate and contrast dose were not significantly related to the incidence of adverse reactions. The incidence of adverse reactions was significantly higher for gadoxetate disodium (0.82%) than gadopentetate dimeglumine (0.43%).
Conclusion: The incidence of acute adverse reactions elicited by Gd-based contrast agents injection was only 0.45%. Younger age was a risk factor for acute reactions. All 4 agents were found to be safe, although gadoxetate disodium showed a relatively higher incidence of adverse reactions.

DOI： 10.2463/mrms.2012-0051

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：W B SAUNDERS CO LTD  

AIM: To evaluate the quality of 100 kVp images with a hybrid iterative reconstruction algorithm level of 40% and 120 kVp (low-tube-current) images with a hybrid iterative reconstruction algorithm level of 60% in low-dose abdominal computed tomography (CT) using almost the same radiation dose.
MATERIALS AND METHODS: This prospective study received institutional review board approval and written informed consent was obtained. One hundred and ten patients undergoing abdominal dynamic CT were randomly assigned to one of two protocols (100 and 120 kVp protocols). Radiation doses of the two protocols were almost identical. The 120 kVp images were post-processed with a hybrid iterative reconstruction algorithm level of 60% (i-120 kVp). The 100 kVp images were post-processed with a hybrid iterative reconstruction algorithm level of 40% (i-100 kVp). The effective dose (ED), image noise, CT attenuation, and signal-to-noise ratio (SNR) of the subcutaneous fat, muscle, liver, pancreas, and kidneys were compared between the protocols using Student's t-test. Qualitative analysis was also performed between the protocols.
RESULTS: There were no significant differences in ED and SNR of any of the regions of interest (ROIs) between the protocols (p &gt; 0.05). However, in the qualitative analysis, unnatural texture was significantly greater in the i-120 kVp than in the i-100 kVp protocol (p &lt; 0.01). There were no other significant differences in the image quality between the protocols (p &gt; 0.05).
CONCLUSION: The combined use of low tube voltage and moderate-level iterative reconstruction techniques can be a more effective strategy for reducing patient radiation dose while attaining acceptable image quality than the use of standard tube voltage, low tube current with high-level iterative reconstruction. (C) 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.crad.2013.04.008

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objective: The objective of this study was to evaluate the effect of a low-tube-voltage technique and hybrid iterative reconstruction (HIR) on image quality at dynamic computed tomography (CT) of the pancreas.
Methods: The study included 18 consecutive patients (10 women, 8 men; mean age, 68.5 +/- 9.5 years) with locally advanced pancreatic cancer who received chemotherapy and had stable disease during the 100- and 120-kV CT studies. The 120-kV images were reconstructed using filtered back projection, and the 100-kV images were postprocessed using filtered back projection and HIR. Scans obtained during 3 pancreatic phases were subjected to quantitative and qualitative analysis.
Results: The mean effective dose was significantly lower under the 100-than the 120-kV protocols (29.2 +/- 3.6 vs 52.1 +/- 5.1 mSv; P &lt; 0.01). The mean contrast-to-noise ratio of the pancreatic cancer and the visual scores were significantly higher under 100 kV with HIR than those under the other 2 protocols (P &lt; 0.01).
Conclusions: Use of low tube voltage and HIR can provide significantly improved image quality at pancreatic dynamic CT.

DOI： 10.1097/RCT.0b013e318296db2b

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To determine whether sufficient pre-surgical treatment information of unruptured intracranial aneurysms can be obtained by using 320-row detector CT angiography (CTA) alone.
We enrolled 40 consecutive patients with unruptured intracranial aneurysms. All patients were prospectively conducted to perform 320-detector CTA as the only preoperative modality. Two blinded readers independently assessed CTA images. Interobserver agreement and the agreement between CTA and surgical findings were determined by calculating the kappa coefficient. The referring neurosurgeons judged the usefulness of the information provided by CTA for treatment decisions.
All patients had surgery without intraarterial digital subtraction angiography. Agreement between CTA and surgical findings was excellent for the aneurysm location (kappa = 1.0) and good for the shape (kappa = 0.71), neck (kappa = 0.74) and its relationship with adjacent branches (kappa = 0.71). Information obtained with 320-detector CTA was highly useful for surgical treatment in 37 of 40 (93 %) patients, although small perforators deriving from the aneurysm in 2 cases were not fully visualized on CTA images.
In most patients with unruptured intracranial aneurysms, sufficient pre-surgical treatment information can be obtained by using 320-detector CTA alone.

DOI： 10.1007/s11604-013-0228-2

Web of Science

PubMed

researchmap

DOI： 10.1002/jmri.24017

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Rationale and Objectives: To compare free-breathing three-dimensional (3D) phase-sensitive inversion recovery (PSIR) with breath-holding two-dimensional (20) IR sequences to determine which is better for detecting and characterizing myocardial late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients.
Materials and Methods: Thirty HCM patients clinically underwent 3.0 T cardiac magnetic resonance imaging that included 3D-PSIR and 2D-IR. The amount of LGE lesions was calculated and expressed as %LGE of the myocardial mass, and the average of the %LGE value reported by two observers was recorded as the final %LGE. We also counted the number of LGE lesions and recorded their location. The myocardium-LGE contrast, margin sharpness, artifacts, and overall image quality were graded on a 4-point grading scale (1.-poor, 2 =fair, 3 = good, 4 = excellent).
Results: The mean %LGE on 2D-IR was 24.7 +/- 0.6, 17.5 +/- 0.6, and 8.5 +/- 0.3, respectively, for the basal, mid-, and apical myocardium; the corresponding values were 24.2 +/- 0.4, 20.0 +/- 0.4, and 7.7 +/- 0.3 on 3D-PSIR (2D-IR versus 3D-PSIR, P =.87). On 2D IR and 3D-PSIR images, 13, 52, and 53, and 9, 74, and 33 LGE lesions were detected in the subendocardial, midwall, subepicardial area, respectively. The myocardium-LGE contrast and overall image quality were significantly higher on 3D-PSIR than 2D-IR images (P &lt;.001); the sequences did not differ significantly with respect to margin sharpness and artifact.
Conclusion: Three-dimensional PSIR sequence yields higher image contrast, better image quality, and greater detection ability for LGE lesions than 2D-IR sequence.

DOI： 10.1016/j.acra.2013.01.014

Web of Science

PubMed

researchmap

DOI： 10.3174/ajnr.A3332

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To evaluate the effect on image quality of a low contrast and radiation dose protocol for cardiac computed tomography (CT) using a low tube voltage, the hybrid-iterative reconstruction algorithm, and a 256-row CT scanner. Before clinical study, we performed phantom experiments to evaluate the hybrid iterative reconstruction technique. We randomly assigned 68 patients undergoing cardiac CT to one of two protocols; 33 were scanned with our conventional 120 kVp protocol, the contrast material (370 mgI/kg body weight) was delivered over 15 s. The other 35 patients underwent scanning at a tube voltage of 80 kVp; the contrast dose, reduced by 50 % (185 mgI/kg), was delivered at the same fractional dose (24.7 mgI/kg/s). The 80 kVp images were post-processed with the 60 % hybrid-iterative reconstruction technique. We evaluated the effective dose (ED), image noise, mean attenuation, and contrast-to-noise ratio (CNR) of each protocol. The hybrid-iterative reconstruction technique offers almost same spatial resolution and noise-power-spectrum curve as compared with filtered back projection reconstruction. There were no decrease in spatial resolution and no shift of spatial frequency in noise power spectrum. The average ED was 74 % lower with the 80- than the 120 kVp protocol (1.4 vs 5.4 mSv). Dunnett's test showed that there were no significant differences in the image noise, mean attenuation, and CNR between hybrid-iterative-reconstructed 80 kVp scans and 120 kVp scans (28.6 +/- A 6.5 vs 25.3 +/- A 4.5, p = 0.18; 475.0 HU +/- A 87.0 vs 445.3 HU +/- A 67.7, p = 0.20; 17.1 HU +/- A 3.5 vs 17.8 HU +/- A 3.1, p = 0.53). The low kVp scan and hybrid-iterative reconstruction algorithm can dramatically decrease the radiation dose and contrast dose with adequate image quality at cardiac CT of thin adults using a 256-row CT scanner.

DOI： 10.1007/s10554-012-0153-y

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：W B SAUNDERS CO LTD  

AIM: To optimize low-kilovoltage (kV) computed tomography (CT) protocols using a hybrid iterative reconstruction (HIR) algorithm at 256-detector-row body CT.
MATERIALS AND METHODS: Based on preliminary phantom studies, three different tube voltage protocols with an equal contrast-to-noise ratio (CNR) were developed. They were a conventional 120 kV protocol with filtered back-projection (FBP), an 80 kV protocol with HIR (a 160% increase in the tube current-time product and a 40% reduction in the contrast medium dose), and a 100 kV protocol with HIR (a 20% reduction in the tube current time product and the contrast medium dose). The clinical study included 70 patients (34 women, 36 men; mean age 70.5 +/- 9.1 years, range 44-92 years) who had undergone CT at 120 kV a mean of 148 +/- 137 days before undergoing low kV contrast- enhanced body CT (80 kV with HIR, n = 35; 100 kV with HIR, n = 35). The estimated effective radiation dose (ED), image noise, and CNR were calculated and the visual image quality was scored on a four-point scale.
RESULTS: Mean ED was 12.3, 8.4, and 15.4 mSv for the 80, 100, and 120 kV protocol, respectively, and significantly lower using the low kV protocols. There was no significant difference in the image noise and CNR between the low kV protocols with HIR and the 120 kV protocol with FBP, or in the visual scores among the three protocols.
CONCLUSION: Without ensuing image-quality degradation, the radiation and contrast medium dose can be reduced with optimal contrast-enhanced CT protocols using a low kV technique and an HIR algorithm. (C) 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.crad.2012.10.014

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

We compared the fixed injection rate protocol (P2) with the fixed injection duration protocol (P1) for coronary CT angiography using the test bolus technique.
We randomly assigned 100 patients to one of two protocols. In P1, they received 0.7 mL/kg Iohexol-350 in an injection duration of 9 s, and we selected a delay of 3 s after peak enhancement of test bolus scan. In P2, they received 0.7 mL/kg Iohexol-350 at an injection rate of 5 mL/s, and we selected a delay after peak enhancement of test bolus scan using the following formula: TID/2-2 s, where TID is the injection duration of full bolus. We compared attenuation values in the ascending aorta and coronary arteries and patient-to-patient enhancement variability at each segment.
At all segments, CT attenuations of P2 were significantly greater than those of P1 (ascending aorta 400 +/- A 64 vs. 368 +/- A 60, P = 0.01; left main trunk 399 +/- A 67 vs. 369 +/- A 55, P = 0.02; proximal-RCA 393 +/- A 66 vs. 363 +/- A 56, P = 0.01). There was no significant difference in patient-to-patient enhancement variability at all segments between the two groups (P &gt; 0.05).
P2 yielded superior vessel enhancement and comparable patient-to-patient enhancement variability compared with P1 in thin patients.

DOI： 10.1007/s11604-012-0158-4

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER IRELAND LTD  

Objectives: To investigate the diagnostic performance of 256-slice cardiac CT for the evaluation of the in-stent lumen by using a hybrid iterative reconstruction (HIR) algorithm combined with a high-resolution kernel.
Methods: This study included 28 patients with 28 stents who underwent cardiac CT. Three different reconstruction images were obtained with: (1) a standard filtered back projection (FBP) algorithm with a standard cardiac kernel (CB), (2) an FBP algorithm with a high-resolution cardiac kernel (CD), and (3) an HIR algorithm with the CD kernel. We measured image noise and kurtosis and used receiver operating characteristics analysis to evaluate observer performance in the detection of in-stent stenosis.
Results: Image noise with FBP plus the CD kernel (80.2 + 15.5 HU) was significantly higher than with FBP plus the CB kernel (28.8 +/- 4.6 HU) and HIR plus the CD kernel (36.1 +/- 6.4 HU). There was no significant difference in the image noise between FBP plus the CB kernel and HIR plus the CD kernel. Kurtosis was significantly better with the CD-than the CB kernel. The kurtosis values obtained with the CD kernel were not significantly different between the FBP- and HIR reconstruction algorithms. The areas under the receiver operating characteristics curves with HIR plus the CD kernel were significantly higher than with FBP plus the CB-or the CD kernel. The difference between FBP plus the CB-or the CD kernel was not significant. The average sensitivity, specificity, and positive and negative predictive value for the detection of in-stent stenosis were 83.3, 50.0, 33.3, and 91.6% for FBP plus the CB kernel, 100, 29.6, 40.0, and 100% for FBP plus the CD kernel, and 100, 54.5, 40.0, and 100% for HIR plus the CD kernel.
Conclusions: The HIR algorithm combined with the high-resolution kernel significantly improved diagnostic performance in the detection of in-stent stenosis. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.ejrad.2012.11.003

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Purpose: To develop a new automatic exposure control (AEC) technique based on the contrast-to-noise ratio (CNR) and provide constant lesion detectability.
Methods: Lesion detectability is affected by factors such as image noise, lesion contrast, and lesion size. We performed ROC analysis to assess the relationship between the optimum CNR and the lesion diameter at various levels of lesion contrast. We then developed a CNR-based AEC algorithm based on lesion detectability. Using CNR- based AEC algorithm, we performed visual evaluation of low-contrast detectability by 5 radiologists on a low-contrast module of the Catphan phantom, a contrast-difference level of 1.0% (difference in the CT number = 10 HU), and objects 3.0-9.0 mm in diameter.
Results: On step-and-shoot scans the mean detection fraction with CNR-based AEC remained almost constant from 88 to 99% regardless of the lesion size. We observed the same trend on helical scans, the mean detection fraction with CNR-based AEC exhibited a high score from 91 to 100%. Although CNR-based AEC maintains higher CNR for smaller size or lower contrast lesion, radiation dose on 3 mm lesion resulted in about 13 times larger than that of 9 mm lesion size. CTDIvol for the CNR-based AEC technique changed dramatically with the SDZ from 7.5 to 100.0 mGy for step-and-shoot scans and from 9.1 to 121.5 mGy for helical scans.
Conclusions: From the viewpoint of ROC analysis-based CNR for lesion detection, CNR-based AEC potentially provide image quality advantages for clinical implementation. (C) 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ejmp.2011.11.004

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Purpose: To evaluate stent lumen visualization by combining high-resolution cardiac kernel and the iterative reconstruction (iDose) on an anthropomorphic moving heart phantom and in patients at coronary computed tomography (CT) angiography.
Materials and Methods: We used the moving heart phantom and a 64 detector-row CT, retrospectively gated helical scanning, and image reconstruction. The heart rate was set at nonpulsating condition of 0 beats/min, 50 beats/min, and 80 beats/min. The 120-kV images were reconstructed in synchronization with electrocardiogram data using filtered back projection (FBP) or iDose algorithm and standard kernel/filter (CB) or high-resolution kernel/filter (CD). We measured image noise, the kurtosis, and stent lumen diameter in the phantom study. We also assessed the visual inspections by two radiologists.
Results: With cardiac motion at 50 and 80 beats/min, the difference of kurtosis improved with CD relative to CB (P &lt; .05). iDose algorithm with level 7 provided lowest noise, with no statistically significance in difference of the kurtosis relative to level 4 (P &gt; .05). Without cardiac motion at 0 beats/min, the stent lumen diameter measurements with CD kernel were better relative to CB kernel (P &lt; .05). In addition, no significant difference was found in stent lumen diameter between iDose level 4 and level 7 (P &gt; .05).
Conclusion: The use of iDose and a sharp kernel allowed improved stent visualization at a lower radiation dose.

DOI： 10.1016/j.acra.2012.06.013

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPANESE CIRCULATION SOC  

Background: Computed tomography venography (CTV) is clinically useful and widely available for the detection of deep vein thrombosis. Disadvantages of CTV are the need for a larger amount of i.v. contrast material (CM) and radiation exposure. A low-tube-voltage technique with iterative reconstruction may overcome this problem. The aim of this study was to investigate the effects of hybrid iterative reconstruction (HIR) on image quality at low-tube-voltage CTV.
Methods and Results: Forty patients (26 women, 14 men; mean age, 59.2 +/- 18.3 years) underwent CTV under an 80- or 120-kV protocol (CT dose index volume=10.3 mGy vs. 14.9 mGy, CM dose=540 mgl/kg vs. 690 mgl/kg) on a 64-detector CT. Quantitative parameters (ie, venous attenuation, image noise, and contrast-to-noise ratio [CNR]) were calculated and the image quality was scored on a 4-point scale. In step 1, the 80- and 120-kV protocols were compared under filtered back projection (FBP). In step 2, the 80-kV protocol with HIR was compared with the 120-kV protocol with FBP. In step 1, the visual scores were significantly higher under the 120-kV protocol; there was no significant difference in CNR between the protocols. In step 2, CNR was significantly higher under the 80-kV protocol with HIR than the 120-kV protocol with FBP. The visual scores of the 2 protocols were comparable.
Conclusions: The 80-kV CTV with HIR allows for a reduction in the radiation dose by 30% and the CM dose by 20% without image quality degradation. (Circ J 2012; 76: 2614-2622)

DOI： 10.1253/circj.CJ-12-0032

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC MEDICINE PRESS LTD  

Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated.
Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard.
Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization.
Results: Detection sensitivity for flat polyps was 31.3%, 44.4%, and 87.5% for lesions measuring 2-3 mm, 4-5 mm, and &gt;= 6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6%, 79.0%, and 91.7%. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients.
Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

DOI： 10.1258/ar.2012.110685

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Objective: To intraindividually compare a low-tube voltage, low-contrast material dose computed tomography (CT) reconstructed with iterative reconstruction (IR) algorithm at standard tube voltage reconstructed with filtered back projection (FBP) and standard-contrast material dose during liver dynamic CT.
Materials and Methods: Twenty-five patients with liver cirrhosis underwent 64-section multidetector CT. One hundred twenty kilovolt (peak) (kV[p]) with standard contrast material dose of 600 mg of iodine per kilogram (protocol A) and 80 kV(p) with low-contrast material dose of 450 mg of iodine per kilogram (protocol B) CT image sets were reconstructed by using FBP algorithm and that of using IR algorithm with a 60%/40% blend of IR-FBP reconstruction at 80-kV(p) image set (protocol C). Scans obtained during 3 hepatic phases were subjected to quantitative and qualitative analysis.
Results: The mean radiation dose and the contrast medium dose were significantly lower under protocols B and C than under protocol A. In all hepatic phases, all signal-to-noise and contrast-to-noise ratios were greater under protocol C than under other protocols at all anatomic sites. Qualitative analysis showed that image noise and diagnostic acceptability were significantly higher under protocol C.
Conclusion: In all hepatic phases, a low-tube voltage, low-contrast material dose CT with IR algorithm yielded better contrast enhancement and image quality than a standard tube voltage, standard contrast material dose CT with FBP in thin adult patients.

DOI： 10.1097/RCT.0b013e31825b821f

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Objectives To evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at 256-slice cardiac CT.
Methods Prospective cardiac CT images from 20 patients were analysed. Paired image sets were created using 3 reconstructions, i.e. filtered back projection (FBP) and moderate- and high-level iterative reconstructions. Quantitative parameters including CT-attenuation, noise, and contrast-to-noise ratio (CNR) were determined in both proximal- and distal coronary segments. Image quality was graded on a 4-point scale.
Results Coronary CT attenuation values were similar for FBP, moderate- and high-level iterative reconstruction at 293 +/- 74-, 290 +/- 75-, and 283 +/- 78 Hounsfield units (HU), respectively. CNR was significantly higher with moderate- and high-level iterative reconstructions (10.9 +/- 3.5 and 18.4 +/- 6.2, respectively) than FBP (8.2 +/- 2.5) as was the visual grading of proximal vessels. Visualisation of distal vessels was better with high-level iterative reconstruction than FBP. The mean number of assessable segments among 289 segments was 245, 260, and 267 for FBP, moderate- and high-level iterative reconstruction, respectively; the difference between FBP and high-level iterative reconstruction was significant Interobserver agreement was significantly higher for moderate- and high-level iterative reconstruction than FBP.
Conclusions Cardiac CT using hybrid iterative reconstruction yields higher CNR and better image quality than FBP.
Key Points
Cardiac CT helps clinicians to assess patients with coronary artery disease
Hybrid iterative reconstruction provides improved cardiac CT image quality
Hybrid iterative reconstruction improves the number of assessable coronary segments
Hybrid iterative reconstruction improves interobserver agreement on cardiac CT

DOI： 10.1007/s00330-011-2361-6

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11604-012-0072-9

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER ROENTGEN RAY SOC  

OBJECTIVE. We investigated whether a hybrid iterative reconstruction (HIR) algorithm improves image quality at low-tube-voltage coronary CT angiography (CTA) compared with filtered back projection (FBP).
SUBJECTS AND METHODS. Eighteen patients (seven men, 11 women; mean age, 67.8 years) underwent retrospectively gated coronary CTA at 80 kV with a volume CT dose index (CTDIvol) of 18.8 mGy on a 64-MDCT scanner. CT images were reconstructed using only FBP and only HIR. For each patient, CT images subjected to the two different reconstructions were reviewed by two observers. Quantitative image quality parameters-that is, CT attenuation (HU) of the coronary arteries, image noise, and contrast-to-noise ratio (CNR)-were calculated and compared for the two reconstruction methods and the overall image quality for each reconstruction was visually scored on a 5-point scale.
RESULTS. The mean estimated effective radiation dose for 80-kV coronary CTA was 4.7 +/- 0.4 (SD) mSv. The two reconstruction methods did not significantly differ with respect to the CT attenuation of the coronary arteries. The image noise was significantly lower with HIR than with FBP (20.3 +/- 5.3 vs 49.4 +/- 12.0 HU, respectively; p &lt; 0.01), and the CNR was significantly higher with HIR than with FBP (29.8 +/- 7.4 vs 12.7 +/- 2.9, p &lt; 0.01). The visual scores for image quality were higher with HIR than with FBP (p &lt; 0.01).
CONCLUSION. The HIR algorithm can reduce image noise and improve image quality at low-tube-voltage coronary CTA.

DOI： 10.2214/AJR.11.7117

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER IRELAND LTD  

Background: Left ventricular diastolic dysfunction (LVDD) plays an important role in heart failure with normal left ventricular ejection fraction (LVEF). Obesity is one of the major comorbid conditions of LVDD. Pericardial fat (PF) is an ectopic fat depot with possible paracrine or mechanical effects on the coronary circulation and myocardial function.
Methods: We measured PF volume on 64 slice computed tomography and analyzed echocardiographic parameters to confirm LVDD in 229 consecutive patients suspected of coronary artery disease with LVEF of more than 50% and no symptomatic heart failure (59% men, 67 +/- 12 years). LVDD was defined as the ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity (E/e') &gt; 10.
Results: PF volume correlated significantly with E/e' (r = 0.21, p &lt; 0.01), left ventricular mass index (r = 0.23, p &lt; 0.001), and left atrial diameter (r = 0.32, p &lt; 0.001). The mean PF volume was significantly greater in patients with LVDD (184 +/- 61 cm(3), n = 141) than in those without LVDD (154 +/- 58, n=88, p &lt; 0.001). Multivariate logistic regression analysis indicated that PF volume correlated significantly with the presence of LVDD (odds ratio: 2.00 per 100 cm(3) increase in PF volume, p = 0.02) independent of age, gender, abdominal obesity, hypertension, and diabetes.
Conclusions: PF volumes are significantly associated with LVDD, independent of other factors such as hypertension or diabetes. PF may be implicated in the pathogenesis of LVDD in patients with normal LVEF. (C) 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jjcc.2012.01.006

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Purpose To evaluate the role of hepatic asialoglycoprotein receptor analysis in the preoperative estimation of postoperative hepatic functional reserve.
Methods We obtained technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (99mTc-GSA) SPECT/CT fusion images in 256 patients with liver disease scheduled for hepatic resection. The liver uptake value corrected for body surface area [LUV(BSA)] and liver uptake ratio (LUR) of the remnant were preoperatively estimated based on the fused images. These values were compared with the postoperative hepatic functional reserve.
Results Significant correlations were observed between LUV(BSA), LUR, and most conventional indicators of hepatic functional reserve. Postoperatively, nonpreserved liver functional reserve was observed in 15 of the 256 patients (5.8%). Remnant LUV(BSA) showed better correlation than remnant LUR or the other indicators. No patients with remnant LUV(BSA) above 28.0 manifested poor nonpreserved functional reserve. Using a LUV(BSA) of 27.0, it was possible to predict postoperative poor hepatic functional reserve at a sensitivity of 91%, specificity of 81%, and accuracy of 81% postoperatively. According to multivariate analysis, a low remnant LUV(BSA) was the only significant independent predictor of poor hepatic functional reserve.
Conclusions Our 99mTc-GSA SPECT/CT fusion imaging method was clinically useful for evaluating regional hepatic function and for predicting postoperative hepatic functional reserve.

DOI： 10.1007/s11604-011-0041-8

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

BACKGROUND: The cardiac CT Appropriate Use Criteria (AUC) were updated in 2010 to reflect technical advances, evolving expert consensus, and rapidly expanding clinical evidence.
OBJECTIVE: We evaluated the effect of the AUC update on their clinical performance, including the completeness and distribution of appropriateness ratings and test outcomes among a consecutive series of patients referred for CT angiography (CTA).
METHODS: The 2006 and 2010 criteria were prospectively applied at the point of service to a consecutive series of patients referred for CTA at a single center (n = 1216). Patient interview and review of available health records were used to determine the CTA indication. The proportions of patients within categories of appropriate (A), uncertain (U), inappropriate (I), and not covered were described and compared between the 2006 and 2010 criteria.
RESULTS: The 2010 criteria significantly reduced the proportion of uncertain (30.5%-11.4%), inappropriate (16.0%-12.9%), and no covered (12.1%0-4.7%; P &lt; 0.001) indications, while increasing the proportion of appropriate tests from 41.4% to 71%. By the 2010 criteria, appropriate indications were more likely to lead to the detection of coronary artery stenosis (11.5% vs 6.7%; P = 0.03) and complete examinations (95.0% vs 90.8%; P = 0.03).
CONCLUSION: The 2010 cardiac CT AUC update lead to more complete classification and to large shifts in the appropriateness ratings, underscoring the importance of ensuring the periodic revision of AUCs for evolving imaging technologies such that they perform optimally as quality measurement and reimbursement tools. (C) 2012 Society of Cardiovascular Computed Tomography. All rights reserved.

DOI： 10.1016/j.jcct.2012.02.003

Web of Science