Gutstein Ariel, Dey Damini, Cheng Victor, Wolak Arik, Gransar Heidi, Suzuki Yasuyuki, Friedman John, Thomson Louise E J, Hayes Sean, Pimentel Raymond, Paz William, Slomka Piotr, Le Meunier Ludovic, Germano Guido, Berman Daniel S
Department of Imaging, Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
J Cardiovasc Comput Tomogr. 2008 Sep-Oct;2(5):311-22. doi: 10.1016/j.jcct.2008.07.003. Epub 2008 Jul 31.
Strategies to reduce the radiation dose of coronary computed tomography angiography (CCTA), while maintaining diagnostic image quality, are imperative for cardiac CT.
We aimed to reduce radiation dose during helical dual-source CCTA by combining lower tube voltage, shortest possible full tube current (FTC) window, and minimal tube current outside the FTC window, and to develop a patient-based algorithm for applying these dose-reduction components.
We compared FTC at 70% of the cardiac cycle (FTC70) to a 45% to 75% window (FTC45-75) using both 100 and 120 kVp (N=118). FTC70 was used in patients with heart rates <70 beats/min, no arrhythmia, age <65 years; 100 kVp was used in patients with body mass index (BMI) <30, a low coronary calcium score (CCS), and no stents. Objective and subjective image quality were assessed.
Compared with FTC45-75 at 120 kVp, radiation dose was reduced by 66% for FTC70 at 100 kVp (mean radiation dose: 4.4 +/- 0.9 mSv) and by 43% for FTC70 at 120 kVp. 99% of 780 segments in the FTC70 group were of diagnostic quality. Noise, signal-to-noise ratio, and contrast-to-noise ratio were comparable between FTC70 and FTC45-75 for both 100 and 120 kVp. BMI, CCS and maximal heart rate variation were predictors of image quality. Tube voltage, FTC window width, scan length, and average heart rate were predictors of radiation dose.
A successful patient-based algorithm for radiation dose reduction during helical CCTA using DSCT has been developed and validated in clinical practice.
在心脏CT中，在保持诊断图像质量的同时降低冠状动脉计算机断层扫描血管造影（CCTA）辐射剂量的策略至关重要。
我们旨在通过结合较低管电压、尽可能短的全管电流（FTC）窗口以及FTC窗口外的最小管电流，来降低螺旋双源CCTA期间的辐射剂量，并开发一种基于患者的算法来应用这些剂量降低组件。
我们使用100和120 kVp将心动周期70%时的FTC（FTC70）与45%至75%窗口（FTC45-75）进行比较（N = 118）。心率<70次/分钟、无心律失常、年龄<65岁的患者使用FTC70；体重指数（BMI）<30、冠状动脉钙化评分（CCS）低且无支架的患者使用100 kVp。评估了客观和主观图像质量。
与120 kVp时的FTC45-75相比，100 kVp时的FTC70辐射剂量降低了66%（平均辐射剂量：4.4±0.9 mSv），120 kVp时的FTC70辐射剂量降低了43%。FTC70组780个节段中有99%具有诊断质量。对于100和120 kVp，FTC70和FTC45-75之间的噪声、信噪比和对比噪声比相当。BMI、CCS和最大心率变异性是图像质量的预测因素。管电压、FTC窗口宽度、扫描长度和平均心率是辐射剂量的预测因素。
已开发出一种基于患者的成功算法，用于在使用双源CT的螺旋CCTA期间降低辐射剂量，并在临床实践中得到验证。
