van der Werf Niels R, Booij Ronald, Greuter Marcel J W, Bos Daniel, van der Lugt A, Budde R P J, van Straten Marcel
Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Int J Cardiovasc Imaging. 2022 Jul;38(7):1613-1619. doi: 10.1007/s10554-022-02540-z. Epub 2022 Feb 3.
To systematically compare coronary artery calcium (CAC) quantification between conventional computed tomography (CT) and photon-counting CT (PCCT) at different virtual monoenergetic (monoE) levels for different heart rates. A dynamic (heart rates of 0, < 60, 60-75, and > 75 bpm) anthropomorphic phantom with three calcification densities was scanned using routine clinical CAC protocols with CT and PCCT. In addition to the standard clinical protocol of 70 keV, PCCT images were reconstructed at monoE levels of 72, 74, and 76 keV. CAC was quantified using Agatston, volume, and mass scores. Agatston scores 95% confidence intervals (CI) were calculated and compared between PCCT and CT. Volume and mass scores were compared with physical quantities. For all CAC densities, routine clinical protocol Agatston scores of static CAC were higher for PCCT compared to CT. At < 60 bpm, Agatston scores at 74 and 76 keV reconstructions were reproducible (overlapping CI) for PCCT and CT. Increased heart rates yielded different Agatston scores for PCCT in comparison with CT, for all monoE levels. Low density CAC volume scores showed the largest deviation from physical volume, with mean deviations of 59% and 77% for CT and PCCT, respectively. Overall, mass scores underestimated physical mass by 10%, 38%, and 59% for low, medium, and high density CAC, respectively. PCCT allows for reproducible Agatston scores for dynamic CAC (< 60 bpm) when reconstructed at monoE levels of 74 or 76 keV, regardless of CAC density. Deviations from physical volume and mass were, in general, large for both CT and PCCT.
为了系统地比较传统计算机断层扫描（CT）和光子计数CT（PCCT）在不同虚拟单能（monoE）水平下针对不同心率的冠状动脉钙化（CAC）定量情况。使用CT和PCCT的常规临床CAC协议对具有三种钙化密度的动态（心率为0、<60、60 - 75和>75次/分钟）人体模型进行扫描。除了70keV的标准临床协议外，PCCT图像还在72、74和76keV的monoE水平下重建。使用阿加斯顿、体积和质量评分对CAC进行定量。计算并比较PCCT和CT之间阿加斯顿评分的95%置信区间（CI）。将体积和质量评分与物理量进行比较。对于所有CAC密度，与CT相比，PCCT的静态CAC常规临床协议阿加斯顿评分更高。在<60次/分钟时，PCCT和CT在74和76keV重建时的阿加斯顿评分具有可重复性（CI重叠）。对于所有monoE水平，心率增加时，PCCT与CT相比产生不同的阿加斯顿评分。低密度CAC体积评分与物理体积的偏差最大，CT和PCCT的平均偏差分别为59%和77%。总体而言，对于低、中、高密度CAC，质量评分分别将物理质量低估了10%、38%和59%。当在74或76keV的monoE水平下重建时，无论CAC密度如何，PCCT对于动态CAC（<60次/分钟）都能产生可重复的阿加斯顿评分。一般来说，CT和PCCT与物理体积和质量的偏差都很大。
