Table1_Virtual calcium removal in calcified coronary arteries with photon-counting detector CT—first in-vivo experience.docx

PurposeTo evaluate the feasibility and accuracy of quantification of calcified coronary stenoses using virtual non-calcium (VNCa) images in coronary CT angiography (CCTA) with photon-counting detector (PCD) CT compared with quantitative coronary angiography (QCA). Materials and methodsThis retrospective, institutional-review board approved study included consecutive patients with calcified coronary artery plaques undergoing CCTA with PCD-CT and invasive coronary angiography between July and December 2022. Virtual monoenergetic images (VMI) and VNCa images were reconstructed. Diameter stenoses were quantified on VMI and VNCa images by two readers. 3D-QCA served as the standard of reference. Measurements were compared using Bland-Altman analyses, Wilcoxon tests, and intraclass correlation coefficients (ICC). ResultsThirty patients [mean age, 64 years ± 8 (standard deviation); 26 men] with 81 coronary stenoses from calcified plaques were included. Ten of the 81 stenoses (12%) had to be excluded because of erroneous plaque subtraction on VNCa images. Median diameter stenosis determined on 3D-QCA was 22% (interquartile range, 11%–35%; total range, 4%–88%). As compared with 3D-QCA, VMI overestimated diameter stenoses (mean differences −10%, p < .001, ICC: .87 and −7%, p < .001, ICC: .84 for reader 1 and 2, respectively), whereas VNCa images showed similar diameter stenoses (mean differences 0%, p = .68, ICC: .94 and 1%, p = .07, ICC: .93 for reader 1 and 2, respectively). ConclusionFirst experience in mainly minimal to moderate stenoses suggests that virtual calcium removal in CCTA with PCD-CT, when feasible, has the potential to improve the quantification of calcified stenoses.研究目的：旨在评估采用光子计数探测器（photon-counting detector, PCD）CT冠脉CT血管造影（coronary CT angiography, CCTA）中的虚拟非钙化（virtual non-calcium, VNCa）图像对钙化性冠状动脉狭窄进行量化的可行性与准确性，并以定量冠脉造影（quantitative coronary angiography, QCA）作为对照进行比较。 材料与方法：本回顾性研究经机构审查委员会批准，纳入2022年7月至12月期间，接受PCD-CT冠脉CT血管造影及有创冠脉造影的、存在钙化冠状动脉斑块的连续性患者。研究重建得到虚拟单能图像（virtual monoenergetic images, VMI）与虚拟非钙化图像（VNCa）。由2名阅片者分别在VMI及VNCa图像上对狭窄直径进行量化，以三维定量冠脉造影（3D-QCA）作为参考标准。采用Bland-Altman分析、Wilcoxon检验及组内相关系数（intraclass correlation coefficient, ICC）对测量结果进行比较。 结果：最终纳入30例患者，平均年龄为（64±8）岁（标准差），其中男性26例，共计81处源自钙化斑块的冠状动脉狭窄。因VNCa图像上斑块去除错误，81处狭窄中有10处（12%）被排除。三维定量冠脉造影（3D-QCA）测得的狭窄直径中位数为22%（四分位间距11%~35%，总体范围4%~88%）。与3D-QCA相比，VMI高估了狭窄直径：阅片者1的平均差异为-10%，p<0.001，组内相关系数（ICC）为0.87；阅片者2的平均差异为-7%，p<0.001，ICC为0.84。而VNCa图像的狭窄直径测量结果与3D-QCA相近：阅片者1的平均差异为0%，p=0.68，ICC为0.94；阅片者2的平均差异为1%，p=0.07，ICC为0.93。 结论：针对以轻度至中度狭窄为主的人群的初步研究结果表明，若技术可行，采用PCD-CT冠脉CT血管造影的虚拟去钙化技术有望提升钙化性狭窄的量化准确性。