From the Departments of Diagnostic Radiology (M.K., S.O., S.S., H.H., T.N., Y.N., T.H.), Cardiovascular Medicine (S.T., K.H., K.T.), Hematology, Rheumatology, and Infectious Disease (Y.K.), and Neurology (M.U.), Graduate School of Medical Sciences, and Department of Medical Physics, Faculty of Life Sciences (Y.F.), Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Radiology. 2023 Mar;306(3):e220542. doi: 10.1148/radiol.220542. Epub 2022 Oct 18.
Background Large studies on the diagnostic performance of CT-derived myocardial extracellular volume fraction (ECV) for detecting cardiac amyloidosis are lacking. A simple and practical index as a surrogate for CT ECV would be clinically useful. Purpose To compare the diagnostic performances between CT-derived myocardial ECV and myocardium-to-lumen signal ratio for the detection of cardiac amyloidosis in a large patient sample. Materials and Methods This retrospective study included patients who underwent CT ECV analysis because of suspected heart failure or cardiomyopathy between January 2018 and July 2021. CT ECV was quantified using routine pre-transcatheter aortic valve replacement planning cardiac CT, pre-atrial fibrillation ablation planning cardiac CT, or coronary CT angiography with the addition of unenhanced and delayed phase cardiac CT scans. The diagnostic performances of CT ECV and myocardium-to-lumen signal ratio in delayed phase cardiac CT (a simplified index not requiring unenhanced CT and hematocrit) for detecting cardiac amyloidosis were evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results Of 552 patients (mean age, 69 years ± 14 [SD]; 295 men), 41 had cardiac amyloidosis. The sensitivity of CT ECV for amyloidosis was 90% (37 of 41 patients [95% CI: 77, 97]), with a specificity of 92% (472 of 511 patients [95% CI: 90, 95]) and optimal ECV cutoff value of 37% (AUC, 0.97 [95% CI: 0.96, 0.99]). The sensitivity of myocardium-to-lumen signal ratio was 88% (36 of 41 patients [95% CI: 74, 96]), with a specificity of 92% (469 of 511 patients [95% CI: 89, 94]) and optimal myocardium-to-lumen signal ratio cutoff value of 0.87 (AUC, 0.96 [95% CI: 0.94, 0.97]; = .27 for comparison with ECV). Conclusion CT-derived myocardial extracellular volume fraction and myocardium-to-lumen signal ratio showed comparable and excellent diagnostic performance in detecting cardiac amyloidosis in a large patient sample. © RSNA, 2022 See also the editorial by Williams in this issue.
背景 目前缺乏关于 CT 衍生的心肌细胞外容积分数（ECV）用于诊断心脏淀粉样变性的大样本研究。一种简单实用的替代 CT ECV 的指标将具有重要的临床意义。目的 比较 CT 衍生的心肌 ECV 与心肌-腔信号比在大样本疑似心力衰竭或心肌病患者中检测心脏淀粉样变性的诊断性能。材料与方法 本回顾性研究纳入了 2018 年 1 月至 2021 年 7 月间因疑似心力衰竭或心肌病而接受 CT ECV 分析的患者。CT ECV 使用常规经导管主动脉瓣置换术前心脏 CT、心房颤动消融术前心脏 CT 或冠状动脉 CT 血管造影加用非增强和延迟相心脏 CT 扫描进行定量。使用接受者操作特征曲线（AUC）下面积、敏感度和特异度评估延迟相心脏 CT 中 CT ECV 和心肌-腔信号比（一种不需要非增强 CT 和红细胞压积的简化指数）对心脏淀粉样变性的诊断性能。结果 在 552 例患者（平均年龄，69 岁±14[标准差]；295 例男性）中，41 例患有心脏淀粉样变性。CT ECV 对淀粉样变性的敏感度为 90%（41 例中的 37 例[95%CI：77%，97%]），特异度为 92%（511 例中的 472 例[95%CI：90%，95%]），最佳 ECV 截断值为 37%（AUC，0.97[95%CI：0.96%，0.99%]）。心肌-腔信号比的敏感度为 88%（41 例中的 36 例[95%CI：74%，96%]），特异度为 92%（511 例中的 469 例[95%CI：89%，94%]），最佳心肌-腔信号比截断值为 0.87（AUC，0.96[95%CI：0.94%，0.97%]）；与 ECV 相比，差异有统计学意义（ =.27）。结论 CT 衍生的心肌 ECV 和心肌-腔信号比在大样本疑似心力衰竭或心肌病患者中检测心脏淀粉样变性的诊断性能相当且非常出色。
