Sartoretti Thomas, Mergen Victor, Dzaferi Amina, Allmendinger Thomas, Manka Robert, Alkadhi Hatem, Eberhard Matthias
Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany.
Int J Cardiovasc Imaging. 2025 Mar;41(3):615-625. doi: 10.1007/s10554-024-03070-6. Epub 2024 Feb 23.
To intra-individually investigate the variation of coronary artery calcium (CAC), aortic valve calcium (AVC), and mitral annular calcium (MAC) scores and the presence of blur artifacts as a function of temporal resolution in patients undergoing non-contrast cardiac CT on a dual-source photon counting detector (PCD) CT. This retrospective, IRB-approved study included 70 patients (30 women, 40 men, mean age 78 ± 9 years) who underwent ECG-gated cardiac non-contrast CT with PCD-CT (gantry rotation time 0.25 s) prior to transcatheter aortic valve replacement. Each scan was reconstructed at a temporal resolution of 66 ms using the dual-source information and at 125 ms using the single-source information. Average heart rate and heart rate variability were calculated from the recorded ECG. CAC, AVC, and MAC were quantified according to the Agatston method on images with both temporal resolutions. Two readers assessed blur artifacts using a 4-point visual grading scale. The influence of average heart rate and heart rate variability on calcium quantification and blur artifacts of the respective structures were analyzed by linear regression analysis. Mean heart rate and heart rate variability during data acquisition were 76 ± 17 beats per minute (bpm) and 4 ± 6 bpm, respectively. CAC scores were smaller on 66 ms (median, 511; interquartile range, 220-978) than on 125 ms reconstructions (538; 203-1050, p < 0.001). Median AVC scores [2809 (2009-3952) versus 3177 (2158-4273)] and median MAC scores [226 (0-1284) versus 251 (0-1574)] were also significantly smaller on 66ms than on 125ms reconstructions (p < 0.001). Reclassification of CAC and AVC risk categories occurred in 4% and 11% of cases, respectively, whereby the risk category was always overestimated on 125ms reconstructions. Image blur artifacts were significantly less on 66ms as opposed to 125 ms reconstructions (p < 0.001). Intra-individual analyses indicate that temporal resolution significantly impacts on calcium scoring with cardiac CT, with CAC, MAC, and AVC being overestimated at lower temporal resolution because of increased motion artifacts eventually leading to an overestimation of patient risk.
在接受双源光子计数探测器（PCD）CT非增强心脏CT检查的患者中，进行个体内研究，以探讨冠状动脉钙化（CAC）、主动脉瓣钙化（AVC）和二尖瓣环钙化（MAC）评分的变化以及模糊伪影的存在与时间分辨率的关系。这项经机构审查委员会（IRB）批准的回顾性研究纳入了70例患者（30名女性，40名男性，平均年龄78±9岁），这些患者在经导管主动脉瓣置换术前接受了PCD-CT的心电图门控心脏非增强CT检查（机架旋转时间0.25秒）。每次扫描均使用双源信息以66毫秒的时间分辨率重建，并使用单源信息以125毫秒的时间分辨率重建。根据记录的心电图计算平均心率和心率变异性。在两种时间分辨率的图像上，根据阿加斯顿方法对CAC、AVC和MAC进行量化。两名阅片者使用4分视觉分级量表评估模糊伪影。通过线性回归分析分析平均心率和心率变异性对各结构钙定量和模糊伪影的影响。数据采集期间的平均心率和心率变异性分别为每分钟76±17次心跳（bpm）和4±6bpm。66毫秒时的CAC评分（中位数，511；四分位间距，220-978）低于125毫秒重建时的评分（538；203-1050，p<0.001）。66毫秒时的AVC评分中位数[2809（2009-3952）对3177（2158-4273）]和MAC评分中位数[226（0-1284）对251（0-1574）]也显著低于125毫秒重建时（p<0.001）。分别有4%和11%的病例发生了CAC和AVC风险类别的重新分类，其中125毫秒重建时风险类别总是被高估。与125毫秒重建相比，66毫秒时的图像模糊伪影明显更少（p<0.001）。个体内分析表明，时间分辨率对心脏CT的钙评分有显著影响，由于运动伪影增加，在较低时间分辨率下CAC、MAC和AVC被高估，最终导致对患者风险的高估。
