Lell Michael M, Panknin Christoph, Saleh Roya, Sayre James W, Schmidt Bernhard, Dinh Howard, Ruehm Stefan G
Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
Invest Radiol. 2007 Jul;42(7):536-41. doi: 10.1097/RLI.0b013e318041f674.
Evaluation of coronary arteries at higher heart rates and in the presence of coronary stents remains problematic. The utilization of dual source computed tomography (DSCT) might improve the visualization of the coronary arteries under these conditions by imaging at a temporal resolution of 83 milliseconds, independent of heart rate.
Vessel phantoms (diameter 2-4 mm) were attached to a robotic device to simulate cardiac motion and scanned with a DSCT system. The phantoms had either inserts leading to 50% stenosis or carried stents. Images were evaluated for motion artifacts and measurements of the normal, stenotic, and in-stent lumen at different heart rates (50-120 bpm) were performed. Quantile regression analysis was performed to investigate heart rate dependence of the measurement errors.
Visualization of the stenoses and stents was possible without motion artifacts at heart rates of up to 120 bpm. Image quality was similar for the static (0 bpm) and the dynamic (50-120 bpm) scans. Errors for diameter measurements of the vessel lumen and the stenotic lumen were low (3-mm vessel: 1-2%), but considerable for in-stent diameter measurements (3-mm stent: 27-32%). A window/level setting of 1500/300 Hounsfield units was more favorable for stent evaluation. No heart rate dependence was found.
Depiction of coronary stents with DSCT is possible across a large range of simulated heart rates without motion artifacts and with image quality superior to that of previous generations of CT scanners.
在较高心率情况下以及存在冠状动脉支架时，对冠状动脉进行评估仍存在问题。双源计算机断层扫描（DSCT）的应用可能通过以83毫秒的时间分辨率进行成像来改善在这些情况下冠状动脉的可视化，且不受心率影响。
将血管模型（直径2 - 4毫米）连接到一个机器人装置上以模拟心脏运动，并用DSCT系统进行扫描。这些模型要么有导致50%狭窄的插入物，要么带有支架。对图像进行运动伪影评估，并在不同心率（50 - 120次/分钟）下对正常、狭窄和支架内管腔进行测量。进行分位数回归分析以研究测量误差对心率的依赖性。
在心率高达120次/分钟时，可以实现对狭窄和支架的可视化且无运动伪影。静态（0次/分钟）和动态（50 - 120次/分钟）扫描的图像质量相似。血管管腔和狭窄管腔直径测量的误差较低（3毫米血管：1 - 2%），但支架内直径测量的误差较大（3毫米支架：27 - 32%）。1500/300亨氏单位的窗宽/窗位设置对支架评估更有利。未发现心率依赖性。
使用DSCT能够在大范围模拟心率下描绘冠状动脉支架，无运动伪影，且图像质量优于前代CT扫描仪。
