Department of Medicine, Weill Cornell Medical College, New York, NY, USA.
Am J Cardiol. 2010 Jul 15;106(2):287-92. doi: 10.1016/j.amjcard.2010.02.038.
Although numerous strategies for radiation dose decrease in coronary computed tomographic angiography are effective, their combined impact on diagnostic performance is not known. We therefore assessed the effect of a standardized coronary computed tomographic angiographic protocol on diagnostic accuracy. We evaluated 80 consecutive patients from 3 sites with coronary computed tomographic angiography and quantitative coronary angiography. All sites initially used nonstandardized protocols; 2 sites then initiated a standardized protocol, and 1 site continued its nonstandardized protocol as a time-overlapping control. Two blinded readers interpreted coronary computed tomographic angiographic studies; a third obtained consensus. A blinded core laboratory performed quantitative coronary angiography. Each segment was graded as <50% or > or =50% diameter stenosis. Compared to those using nonstandardized protocols (n = 35), studies using standardized protocols (n = 45) had a trend to increased use of prospective gating (p = 0.09), lower voltage (p <0.01), decreased current (p <0.01), and shorter scan length (p <0.01). Median (interquartile range) radiation dose decreased from 5.7 mSv (4.0 to 10.8) to 2.0 mSv (1.3 to 3.4, p <0.001). There were no significant differences in sensitivity (100%, 20 of 20, vs 100%, 18 of 18, p = 1.0), specificity (93%, 14 of 15, vs 85%, 23 of 27, p = 0.61), or accuracy (97%, 34 of 35, vs 91%, 41 of 45, p = 0.27) by patient; sensitivity (83%, 33 of 40, vs 83%, 25 of 30, p = 0.93), specificity (92%, 86 of 93, vs 92%, 134 of 146, p = 0.85), or accuracy (89%, 119 of 133, vs 90%, 159 of 176, p = 0.80) by artery; or sensitivity (80%, 44 of 55, vs 72%, 26 of 36, p = 0.74), specificity (94%, 332 of 353, vs 94%, 499 of 531, p = 0.96), or accuracy (92%, 376 of 408, vs 93%, 525 of 567, p = 0.80) by segment. In conclusion, a standardized dose-decrease protocol for coronary computed tomographic angiography decreases radiation dose without affecting diagnostic performance.
尽管有许多降低冠状动脉 CT 血管造影辐射剂量的策略是有效的，但它们对诊断性能的综合影响尚不清楚。因此，我们评估了标准化冠状动脉 CT 血管造影方案对诊断准确性的影响。我们评估了来自 3 个地点的 80 例连续接受冠状动脉 CT 血管造影和定量冠状动脉血管造影的患者。所有地点最初均使用非标准化方案；其中 2 个地点随后启动了标准化方案，而 1 个地点继续作为时间重叠对照使用非标准化方案。2 位盲法读者对冠状动脉 CT 血管造影研究进行了解读；第 3 位读者得出了共识。一个盲法核心实验室进行了定量冠状动脉血管造影。每个节段的分级为 <50%或≥50%的直径狭窄。与使用非标准化方案的患者（n=35）相比，使用标准化方案的患者（n=45）前瞻性门控的使用趋势增加（p=0.09），电压较低（p<0.01），电流降低（p<0.01），扫描长度缩短（p<0.01）。中位数（四分位数范围）辐射剂量从 5.7 mSv（4.0 至 10.8）降至 2.0 mSv（1.3 至 3.4，p<0.001）。患者的敏感度（100%，20/20，vs 100%，18/18，p=1.0）、特异度（93%，14/15，vs 85%，23/27，p=0.61）或准确度（97%，34/35，vs 91%，41/45，p=0.27）均无显著差异；按动脉（敏感度 83%，33/40，vs 83%，25/30，p=0.93）、特异度（92%，86/93，vs 92%，134/146，p=0.85）或准确度（89%，119/133，vs 90%，159/176，p=0.80）；或节段（敏感度 80%，44/55，vs 72%，26/36，p=0.74）、特异度（94%，332/353，vs 94%，499/531，p=0.96）或准确度（92%，376/408，vs 93%，525/567，p=0.80）无显著差异。结论：冠状动脉 CT 血管造影剂量降低标准化方案可降低辐射剂量，而不影响诊断性能。
