Language：Japanese   Publisher：横浜市立大学医学会  

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DOI： 10.3390/tomography10110130

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Background/Objectives: The usefulness of dual-energy computed tomography (DECT) for low absorption in the parenchymal phase and contrast effects in the delayed phase for pancreatic cancer is not clear. Therefore, the diagnostic capability of low-KeV images obtained using DECT for pancreatic cancer in the pancreatic parenchymal and delayed phases was evaluated quantitatively and qualitatively. Methods: Twenty-five patients with pancreatic cancer who underwent contrast-enhanced DECT were included. A total of 50 and 70 KeV CT images, classified as low-keV and conventional CT-equivalent images, were produced, respectively. The tumor-to-pancreas contrast (Hounsfield units [HU]) in the pancreatic parenchymal and delayed phases was calculated by subtracting the CT value of the pancreatic tumor from that of normal parenchyma. Results: The median tumor-to-pancreas contrast on 50 KeV CT in the pancreatic parenchymal phase (133 HU) was higher than that on conventional CT (68 HU) (p < 0.001). The median tumor-to-pancreas contrast in the delayed phase was -28 HU for 50 KeV CT and -9 HU for conventional CT (p = 0.545). For tumors < 20 mm, the tumor-to-pancreas contrast of 50 KeV CT (-39 HU) had a significantly clearer contrast effect than that of conventional CT (-16.5 HU), even in the delayed phase (p = 0.034). Conclusions: These 50 KeV CT images may clarify the low-absorption areas of pancreatic cancer in the pancreatic parenchymal phase. A good contrast effect was observed in small pancreatic cancers on 50 KeV delayed-phase images, suggesting that DECT is useful for the visualization of early pancreatic cancer with a small tumor diameter.

DOI： 10.3390/tomography10100117

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BACKGROUND: The utility of synthetic ECV, which does not require hematocrit values, has been reported; however, high-quality CT images are essential for accurate quantification. Second-generation Deep Learning Reconstruction (DLR) enables low-noise and high-resolution cardiac CT images. The aim of this study is to compare the differences among four reconstruction methods (hybrid iterative reconstruction (HIR), model-based iterative reconstruction (MBIR), DLR, and second-generation DLR) in the quantification of synthetic ECV. METHODS: We retrospectively analyzed 80 patients who underwent cardiac CT scans, including late contrast-enhanced CT (derivation cohort: n = 40, age 71 ± 12 years, 24 males; validation cohort: n = 40, age 67 ± 11 years, 25 males). In the derivation cohort, a linear regression analysis was performed between the hematocrit values from blood tests and the CT values of the right atrial blood pool on non-contrast CT. In the validation cohort, synthetic hematocrit values were calculated using the linear regression equation and the right atrial CT values from non-contrast CT. The correlation and mean difference between synthetic ECV and laboratory ECV calculated from actual blood tests were assessed. RESULTS: Synthetic ECV and laboratory ECV showed a high correlation across all four reconstruction methods (R ≥ 0.95, p < 0.001). The bias and limit of agreement (LOA) in the Bland-Altman plot were lowest with the second-generation DLR (hybrid IR: bias = -0.21, LOA: 3.16; MBIR: bias = -0.79, LOA: 2.81; DLR: bias = -1.87, LOA: 2.90; second-generation DLR: bias = -0.20, LOA: 2.35). CONCLUSIONS: Synthetic ECV using second-generation DLR demonstrated the lowest bias and LOA compared to laboratory ECV among the four reconstruction methods, suggesting that second-generation DLR enables more accurate quantification.

DOI： 10.3390/jcdd11100304

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BACKGROUND: The usefulness of monitoring treatment effect of tafamidis using magnetic resonance imaging (MRI) extracellular volume fraction (ECV) has been reported. OBJECTIVE: we conducted a meta-analysis to evaluate the usefulness of this method. METHODS: Data from 246 ATTR-CMs from six studies were extracted and included in the analysis. An inverse variance meta-analysis using a random effects model was performed to evaluate the change in MRI-ECV before and after tafamidis treatment. The analysis was also performed by classifying the patients into ATTR-CM types (wild-type or hereditary). RESULTS: ECV change before and after tafamidis treatment was 0.33% (95% CI: -1.83-2.49, I2 = 0%, p = 0.76 for heterogeneity) in the treatment group and 4.23% (95% CI: 0.44-8.02, I2 = 0%, p = 0.18 for heterogeneity) in the non-treatment group. The change in ECV before and after treatment was not significant in the treated group (p = 0.76), but there was a significant increase in the non-treated group (p = 0.03). There was no difference in the change in ECV between wild-type (95% CI: -2.65-3.40) and hereditary-type (95% CI: -9.28-4.28) (p = 0.45). CONCLUSIONS: The results of this meta-analysis suggest that MRI-ECV measurement is a useful imaging method for noninvasively evaluating the efficacy of tafamidis treatment for ATTR-CM.

DOI： 10.3390/tomography10080097

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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

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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

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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

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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

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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

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DOI： 10.1002/ehf2.14919

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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

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Publishing type：Research paper (scientific journal)   Publisher：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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

DOI： 10.1093/noajnl/vdad043

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DOI： 10.1097/CM9.0000000000002652

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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

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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

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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

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DOI： 10.5603/CJ.a2023.0004

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DOI： 10.21037/qims-22-522

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Publishing type：Research paper (scientific journal)   Publisher：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

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DOI： 10.1016/j.ejim.2022.08.028

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DOI： 10.1002/ehf2.14095

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DOI： 10.1002/ehf2.14236

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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

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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

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DOI： 10.1016/j.hjc.2022.07.004

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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

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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

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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

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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

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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

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DOI： 10.1016/j.amjcard.2022.02.010

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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

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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

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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

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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

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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

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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

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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

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DOI： 10.1093/ehjci/jeab055

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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

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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

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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

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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

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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

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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

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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

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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

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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

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DOI： 10.1161/CIRCIMAGING.120.012177

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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

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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

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：(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。

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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

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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

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DOI： 10.1177/0284185120902393

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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

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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

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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

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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

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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

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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

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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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

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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

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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

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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

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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

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer  

DOI： 10.1007/s11604-020-00977-7

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RATIONALE AND OBJECTIVES: To compare the objective and subjective image qualities between single-energy computed tomography (CT) at 70 kVp and virtual monoenergetic imaging (VMI) of dual-source dual-energy CT for CT angiography with 180 mgI/kg. MATERIALS AND METHODS: Total 63 patients scanned with 180 mgI/kg were randomly divided into two groups: Group A (32 patients) underwent CT angiography at 70-kVp, and Group B (31 patients) underwent dual-energy CT. VMI sets were generated at 10-keV increments between 40 and 100 keV. We calculated aortic attenuation, contrast-to-noise-ratio (CNR), signal-to-noise-ratio, figure of merit of CNR, and effective dose for each protocol. Three radiologists scored overall image quality and various arteries' visibility using a four-point scale. Quantitative and qualitative comparisons between 70 kVp and VMI with the highest CNR were performed with the two-tailed t test or Kruskal-Wallis test. RESULTS: The 40-keV images offered the highest CNR among VMIs. Aortic attenuation at 70 kVp was significantly lower than that at 40 keV (p < 0.001). However, the signal-to-noise-ratio, CNR, and figure of merit of CNR were significantly higher at 70 kVp than those at 40-keV (p < 0.001, p < 0.05, and p < 0.05, respectively). The effective dose of each group was almost equal. The qualitative visibility scores for various arteries, except the ascending and upper-abdominal aorta, were also better at 70 kVp than those at 40 keV. CONCLUSION: Aortic attenuation at 70 kVp with 180 mg I/kg was lower than that of VMI at 40 keV, and the objective and subjective image qualities were higher at 70 kVp than those at 40 keV.

DOI： 10.1016/j.acra.2019.07.016

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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

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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

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DOI： 10.1007/s11604-019-00906-3

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NLM (Medline)  

DOI： 10.1097/RCT.0000000000000958

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DOI： 10.1097/RCT.0000000000000970

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DOI： 10.1007/s00330-019-06337-y

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DOI： 10.1016/j.jcmg.2019.07.010

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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

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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

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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

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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

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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

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DOI： 10.1080/13506129.2019.1597701

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DOI： 10.1253/circj.CJ-18-1062

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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

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DOI： 10.1148/rg.2019194005

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DOI： 10.1016/j.radcr.2019.02.016

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DOI： 10.1007/s00330-018-5733-3

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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

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PURPOSE: The hybrid compressed sensing (hybrid-CS) technique can shorten the acquisition time compared with the sensitivity encoding (SENSE) technique in lumbar MRI. To evaluate the feasibility of a hybrid-CS technique in comparison with 3D isotropic T2-weighted turbo spin-echo (3D volume isotropic turbo spin-echo acquisition [VISTA]) MRI of the lumbar spine. MATERIALS AND METHODS: The Institutional Review Board approved this study and informed consent was obtained from participants prior to study entry. Sixteen healthy volunteers underwent lumbar spine 3D VISTA with conventional parallel imaging for SENSE and hybrid-CS at 3T. We recorded the image acquisition times of SENSE and hybrid-CS. We compared the signal-to-noise ratio (SNR) in spine, cerebrospinal fluid (CSF), lumbar disc, epidural fat, and erector spinae muscle, and the contrast of spine, CSF, and disc, and performed qualitative image analysis assessment, between the two image sequences. RESULTS: The image acquisition time for hybrid-CS was 39.2% shorter than that of SENSE (218.4/358.8 s). The contrast of CSF and SNR of the spine was significantly higher with hybrid-CS than with SENSE (P < 0.05). The SNR of the disc and muscle was significantly higher with SENSE than with hybrid-CS (P < 0.05). There were no significant differences in the contrast of spine, disc, and fat, and SNR of CSF and fat between hybrid-CS and SENSE. There were no significant differences in the qualitative evaluation between hybrid-CS and SENSE. CONCLUSION: Compared with SENSE, hybrid-CS for 3D VISTA can shorten image acquisition time without sacrificing image quality.

DOI： 10.2463/mrms.mp.2018-0132

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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

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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

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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

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DOI： 10.1080/13506129.2019.1582021

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DOI： 10.5603/CJ.2019.0013

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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

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DOI： 10.1016/j.crad.2018.08.010

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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

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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

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DOI： 10.1016/j.clinimag.2018.01.020

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DOI： 10.1148/rg.2018180041

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DOI： 10.1016/j.jccase.2018.05.003

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DOI： 10.1007/s00380-017-1104-2

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DOI： 10.1080/13506129.2018.1424625

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer New York LLC  

DOI： 10.1007/s10140-018-1610-2

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DOI： 10.1016/j.ejmp.2018.04.388

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DOI： 10.1097/MD.0000000000010810

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DOI： 10.1097/MD.0000000000010447

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DOI： 10.1259/bjr.20170632

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The aim of this study was to evaluate the effect of patient characteristics on the contrast agent dosage that is required to reach effective enhancement of the inferior vena cava (IVC) on computed tomography venographs (CTV).This retrospective study included 50 patients who underwent CTV at 80 kVp. The contrast injection protocol (iodine 600 mg/kg) was tailored to their body weight. We calculated the required contrast agent volume (CAVmean-IVC) to reach the mean enhancement of IVC. We performed univariate and multivariate linear regression analyses between the sex, age, body weight (BW), lean body weight (LBW), body surface area (BSA), height (HT), estimated glomerular filtration rate (eGFR), and CAVmean-IVC.The univariate linear regression analysis show that HT, BW, LBW, and BSA were significantly correlated with CAVmean-IVC (P < .01 for all). The CAVmean-IVC was significantly higher for males than females (P < .01). Multivariate regression analysis showed that BW, LBW, and BSA had a statistically significant effect on CAVmean-IVC. There was no significant correlation of age, HT, or eGFR with CAVmean-IVC.BW, LBW, and BSA each had an independent significant effect on CAVmean-IVC. The conventional BW-tailored contrast injection protocol might be insufficient for CTV.

DOI： 10.1097/MD.0000000000010231

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DOI： 10.2463/mrms.mp.2017-0037

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PURPOSE: The purpose of this study is to determine whether iterative model reconstruction (IMR) optimized for brain CT could improve the detection of acute stroke in the setting of thin image slices and narrow window settings. METHODS: We retrospectively reviewed 27 patients who presented acute middle cerebral artery (MCA) stroke. Images were reconstructed using filtered back projection (FBP; 1- and 5-mm slice thickness) and IMR (1 mm thickness), and contrast-to-noise ratios (CNRs) of infarcted and non-infarcted areas were compared. To analyze the performance of acute MCA stroke detection, we used receiver operating characteristic (ROC) curve techniques and compared 5-mm FBP with standard and narrow window settings, and 1-mm FBP and IMR with narrow window settings. RESULTS: The CNR in 1-mm IMR (1.1 ± 1.0) was significantly higher than in 5- (0.8 ± 0.7) and 1-mm FBP (0.4 ± 0.4) (p < 0.001). Furthermore, the average area under the ROC curve was significantly higher with 1-mm IMR with narrow window settings (0.90, 95% CI: 0.86, 0.94) than it was with 5-mm FBP (0.78, 95% CI: 0.72, 0.83). CONCLUSION: The combination of thin image slices and narrow window settings under IMR reconstruction provide better diagnostic performance for acute MCA stroke than conventional reconstruction methods.

DOI： 10.1007/s00234-018-1982-8

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DOI： 10.1016/j.acra.2017.10.008

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DOI： 10.1007/s00330-017-5114-3

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DOI： 10.1007/s00380-017-1069-1

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DOI： 10.1016/S0735-1097(18)31718-2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Lippincott Williams and Wilkins  

DOI： 10.1161/CIRCIMAGING.117.007277

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DOI： 10.1016/j.crad.2017.09.006

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DOI： 10.1007/s00330-017-5240-y

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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

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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

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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

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DOI： 10.1016/j.ejrad.2017.11.009

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DOI： 10.1007/s00330-017-4845-5

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DOI： 10.1097/RCT.0000000000000626

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DOI： 10.1016/j.ejrad.2017.09.012

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DOI： 10.1016/j.jcct.2017.09.010

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DOI： 10.1002/ccr3.1180

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DOI： 10.1016/j.clinimag.2017.06.006

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DOI： 10.1016/j.acra.2017.02.006

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PURPOSE: To develop a prediction model to distinguish between transition zone (TZ) cancers and benign prostatic hyperplasia (BPH) on multi-parametric prostate magnetic resonance imaging (mp-MRI). MATERIALS AND METHODS: This retrospective study enrolled 60 patients with either BPH or TZ cancer, who had undergone 3 T-MRI. We generated ten parameters for T2-weighted images (T2WI), diffusion-weighted images (DWI) and dynamic MRI. Using a t-test and multivariate logistic regression (LR) analysis to evaluate the parameters' accuracy, we developed LR models. We calculated the area under the receiver operating characteristic curve (ROC) of LR models by a leave-one-out cross-validation procedure, and the LR model's performance was compared with radiologists' performance with their opinion and with the Prostate Imaging Reporting and Data System (Pi-RADS v2) score. RESULTS: Multivariate LR analysis showed that only standardized T2WI signal and mean apparent diffusion coefficient (ADC) maintained their independent values (P < 0.001). The validation analysis showed that the AUC of the final LR model was comparable to that of board-certified radiologists, and superior to that of Pi-RADS scores. CONCLUSION: A standardized T2WI and mean ADC were independent factors for distinguishing between BPH and TZ cancer. The performance of the LR model was comparable to that of experienced radiologists. KEY POINTS: • It is difficult to diagnose transition zone (TZ) cancer. • We performed quantitative image analysis in multi-parametric MRI. • Standardized-T2WI and mean-ADC were independent factors for diagnosing TZ cancer. • We developed logistic-regression analysis to diagnose TZ cancer accurately. • The performance of the logistic-regression analysis was higher than PIRADSv2.

DOI： 10.1007/s00330-017-4775-2

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DOI： 10.1007/s00330-017-4773-4

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DOI： 10.1007/s10140-017-1511-9

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DOI： 10.1097/RCT.0000000000000583

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DOI： 10.1148/radiol.2017161966

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OBJECTIVES: To retrospectively evaluate the image quality and radiation dose of 100-kVp scans with sinogram-affirmed iterative reconstruction (IR) for unenhanced head CT in adolescents. METHODS: Sixty-nine patients aged 12-17 years underwent head CT under 120- (n = 34) or 100-kVp (n = 35) protocols. The 120-kVp images were reconstructed with filtered back-projection (FBP), 100-kVp images with FBP (100-kVp-F) and sinogram-affirmed IR (100-kVp-S). We compared the effective dose (ED), grey-white matter (GM-WM) contrast, image noise, and contrast-to-noise ratio (CNR) between protocols in supratentorial (ST) and posterior fossa (PS). We also assessed GM-WM contrast, image noise, sharpness, artifacts, and overall image quality on a four-point scale. RESULTS: ED was 46% lower with 100- than 120-kVp (p < 0.001). GM-WM contrast was higher, and image noise was lower, on 100-kVp-S than 120-kVp at ST (p < 0.001). CNR of 100-kVp-S was higher than of 120-kVp (p < 0.001). GM-WM contrast of 100-kVp-S was subjectively rated as better than of 120-kVp (p < 0.001). There were no significant differences in the other criteria between 100-kVp-S and 120-kVp (p = 0.072-0.966). CONCLUSIONS: The 100-kVp with sinogram-affirmed IR facilitated dramatic radiation reduction and better GM-WM contrast without increasing image noise in adolescent head CT. KEY POINTS: • 100-kVp head CT provides 46% radiation dose reduction compared with 120-kVp. • 100-kVp scanning improves subjective and objective GM-WM contrast. • Sinogram-affirmed IR decreases head CT image noise, especially in supratentorial region. • 100-kVp protocol with sinogram-affirmed IR is suited for adolescent head CT.

DOI： 10.1007/s00330-016-4679-6

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DOI： 10.1016/j.ejrad.2017.05.011

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DOI： 10.1253/circj.CJ-16-1259

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DOI： 10.1007/s00330-016-4618-6

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DOI： 10.1097/MD.0000000000006973

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DOI： 10.1016/j.jcct.2017.01.005

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DOI： 10.1097/RCT.0000000000000541

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DOI： 10.1038/hr.2016.159

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DOI： 10.1016/j.acra.2016.11.003

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INTRODUCTION: The purpose of this study was to evaluate the feasibility of a contrast medium (CM), radiation dose reduction protocol for cerebral bone-subtraction CT angiography (BSCTA) using 80-kVp and sinogram-affirmed iterative reconstruction (SAFIRE). METHODS: Seventy-five patients who had undergone BSCTA under the 120- (n = 37) or the 80-kVp protocol (n = 38) were included. CM was 370 mgI/kg for the 120-kVp and 296 mgI/kg for the 80-kVp protocol; the 120- and the 80-kVp images were reconstructed with filtered back-projection (FBP) and SAFIRE, respectively. We compared effective dose (ED), CT attenuation, image noise, and contrast-to-noise ratio (CNR) of two protocols. We also scored arterial contrast, sharpness, depiction of small arteries, visibility near skull base/clip, and overall image quality on a four-point scale. RESULTS: ED was 62% lower at 80- than 120-kVp (0.59 ± 0.06 vs 1.56 ± 0.13 mSv, p < 0.01). CT attenuation of the internal carotid artery (ICA) and middle cerebral artery (MCA) was significantly higher on 80- than 120-kVp (ICA: 557.4 ± 105.7 vs 370.0 ± 59.3 Hounsfield units (HU), p < 0.01; MCA: 551.9 ± 107.9 vs 364.6 ± 62.2 HU, p < 0.01). The CNR was also significantly higher on 80- than 120-kVp (ICA: 46.2 ± 10.2 vs 36.9 ± 7.6, p < 0.01; MCA: 45.7 ± 10.0 vs 35.7 ± 9.0, p < 0.01). Visibility near skull base and clip was not significantly different (p = 0.45). The other subjective scores were higher with the 80- than the 120-kVp protocol (p < 0.05). CONCLUSION: The 80-kVp acquisition with SAFIRE yields better image quality for BSCTA and substantial reduction in the radiation and CM dose compared to the 120-kVp with FBP protocol.

DOI： 10.1007/s00234-016-1776-9

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DOI： 10.1016/j.ijcard.2016.11.054

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DOI： 10.1253/circj.CJ-16-0873

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BACKGROUND: An optimal metal artifact reduction (MAR) technique is needed for a reliable and accurate image-based diagnosis. PURPOSE: Using a 320-row scanner, we compared the dual-energy computed tomography (CT)-based monochromatic and the single-energy metal artifact reduction (SEMAR) techniques for CT venography (CTV) to identify the better imaging method for diagnosing deep vein thrombosis (DVT) in patients who had undergone knee replacement surgery. MATERIAL AND METHODS: Twenty-three consecutive patients with suspected DVT after unilateral knee replacement surgery underwent dual-energy CT (135/80 kVp). Monochromatic images of 35-135 keV were generated; the monochromatic image with the best signal-to-noise ratio (SNR) of the popliteal vein near the metal prosthesis were selected. The projection data of 80 kVp were reconstructed using MAR algorithm. The mean SNR ON MAR and the best SNR ON monochromatic images were compared. Two radiologists evaluated visualization of the metal artifacts on a four-point scale where 1 = extensive artifacts, 2 = strong artifacts, 3 = mild artifacts, and 4 = minimal artifacts. RESULTS: The mean SNR was significantly higher on the MAR than the monochromatic images (12.8 ± 4.7 versus 7.7 ± 5.1, P < 0.01) and the visual scores were significantly higher for MAR than monochromatic images (2.6 ± 0.8 versus 1.3 ± 0.4, P < 0.01). CONCLUSION: For CTV after knee replacement surgery, the MAR technique is superior to the monochromatic imaging technique.

DOI： 10.1177/2058460117693463

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DOI： 10.1007/s00380-016-0816-z

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DOI： 10.1016/j.ejmp.2016.10.011

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DOI： 10.1016/j.acra.2016.07.005

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DOI： 10.1016/j.acra.2016.05.011

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DOI： 10.1007/s11604-016-0576-9

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DOI： 10.1007/s11604-016-0556-0

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DOI： 10.1007/s00330-015-3950-6

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DOI： 10.1007/s00330-016-4435-y

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DOI： 10.1016/j.ijcard.2016.01.051

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DOI： 10.1177/0284185115575537

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DOI： 10.1016/j.jcct.2015.10.006

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DOI： 10.1016/j.acra.2015.11.003

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DOI： 10.3174/ajnr.A4496

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DOI： 10.1007/s00330-015-3822-0

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DOI： 10.1016/j.ejmp.2015.12.005

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DOI： 10.1007/s10554-015-0782-z

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DOI： 10.1016/j.ejmp.2015.05.018

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DOI： 10.1177/0284185114555152

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DOI： 10.1177/0284185115590285

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DOI： 10.1177/0284185114549826

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DOI： 10.1007/s11604-015-0471-9

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DOI： 10.1097/RCT.0000000000000228

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DOI： 10.1007/s11604-015-0429-y

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DOI： 10.1253/circj.CJ-14-0932

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DOI： 10.1186/s40064-015-0866-1

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DOI： 10.1016/j.ejmp.2014.10.003

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DOI： 10.1016/j.acra.2014.09.020

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DOI： 10.1016/j.jcct.2014.12.002

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DOI： 10.1120/jacmp.v16i1.5082

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DOI： 10.1007/s12149-014-0872-3

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DOI： 10.1016/j.ejmp.2014.02.005

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DOI： 10.1016/j.ejmp.2013.10.003

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DOI： 10.1016/j.amjcard.2014.02.029

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DOI： 10.1007/s11604-014-0285-1

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DOI： 10.1007/s00380-013-0338-x

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DOI： 10.1016/j.jcct.2013.12.010

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DOI： 10.3174/ajnr.A3660

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DOI： 10.1097/RCT.0b013e3182a9a518

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DOI： 10.1016/j.jjcc.2013.07.005

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DOI： 10.1016/j.acra.2013.10.002

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Kurume University School of Medicine  

DOI： 10.2739/kurumemedj.MS64002

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DOI： 10.2463/mrms.2012-0051

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DOI： 10.1016/j.crad.2013.04.008

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DOI： 10.1097/RCT.0b013e318296db2b

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DOI： 10.1007/s11604-013-0228-2

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DOI： 10.1002/jmri.24017

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DOI： 10.1016/j.acra.2013.01.014

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DOI： 10.3174/ajnr.A3332

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DOI： 10.1007/s10554-012-0153-y

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DOI： 10.1016/j.crad.2012.10.014

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DOI： 10.1007/s11604-012-0158-4

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DOI： 10.1016/j.ejrad.2012.11.003

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DOI： 10.1016/j.ejmp.2011.11.004

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DOI： 10.1016/j.acra.2012.06.013

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DOI： 10.1253/circj.CJ-12-0032

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DOI： 10.1258/ar.2012.110685

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DOI： 10.1097/RCT.0b013e31825b821f

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PURPOSE: We compared quantitative indices estimated by use of technetium-(99m) galactosyl human serum albumin ((99m)Tc-GSA) single-photon emission computed tomography (SPECT)/computed tomography (CT) fused imaging and hepatic fibrosis in patients with chronic liver disease. MATERIALS AND METHODS: On the basis of pathological findings we divided 161 patients into non-severe and severe fibrosis groups (n = 81 and n = 80, respectively). We measured 2 indices by (99m)Tc-GSA SPECT/CT fused imaging: liver uptake value (LUV) = [radioactivity (whole liver)/radioactivity (injected)] × 100/body surface area, and functional liver index (FLI) = [radioactivity (hepatocytes)/radioactivity (injected)] × 100/liver volume. We compared these indices with biochemical and histopathological results. RESULTS: Univariate and multivariate analyses showed that FLI, LUV, LHL15, and prothrombin time were significant independent predictors of severe fibrosis. On the basis of receiver operating characteristics analysis, the areas under curve values of FLI, LUV, LHL15, and prothrombin time for predicting severe fibrosis were 0.83, 0.73, 0.69, and 0.68, respectively. Using an FLI value of 0.053, it was possible to predict severe fibrosis with 65 % sensitivity, 88 % specificity, and 76 % accuracy. CONCLUSION: Assessment of functional hepatocytes by use of (99m)Tc-GSA SPECT/CT fused images is useful for identifying pathological liver fibrosis.

DOI： 10.1007/s11604-012-0072-9

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DOI： 10.1007/s00330-011-2361-6

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DOI： 10.2214/AJR.11.7117

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DOI： 10.1016/j.jjcc.2012.01.006

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DOI： 10.1007/s11604-011-0041-8

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DOI： 10.1016/j.jcct.2012.02.003

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DOI： 10.1016/j.ejmp.2011.01.003

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DOI： 10.1007/s11604-011-0003-1

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DOI： 10.1002/jmri.22728

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DOI： 10.3174/ajnr.A2725

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DOI： 10.1097/RCT.0b013e31822a563d

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DOI： 10.1016/j.acra.2011.03.007