Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong.
Acad Radiol. 2010 Nov;17(11):1386-93. doi: 10.1016/j.acra.2010.06.011.
The aims of this study were to determine the optimal image reconstruction intervals for the systolic and diastolic phases of coronary computed tomographic angiography on 256-slice computed tomography and to assess their associated motion artifacts.
One hundred twenty-six patients were recruited (mean heart rate [HR], 72.1 beats/min; heart rate variability, 1.3 beats/min). Twenty data sets were reconstructed in 5% steps through 0% to 95% of the R-R interval. Two reviewers discriminated optimal reconstruction intervals for 15 segments distributed in three coronary arteries on the basis of motion artifacts, which were graded from 1 (no motion artifacts) to 4 (severe motion artifacts preventing diagnosis). Patients were then stratified into four HR groups for motion score comparison according to the results of a correlation analysis of HR and motion scores.
The optimal systolic and diastolic reconstruction intervals were 44.4 ± 3.8% and 77.4 ± 3.7%, respectively. The mean motion scores for systolic, diastolic, and combined systolic and diastolic (S+D) reconstructions were 1.8 ± 0.3, 1.8 ± 0.5, and 1.5 ± 0.3, respectively. Combined S+D reconstruction improved diagnostic evaluability to 100% and showed fewer motion artifacts compared to single-phase reconstructions for all HR ranges (S+D vs systolic, P < .05 for HR < 85 beats/min; S+D vs diastolic, P < .05 for HRs of 73-84 beats/min). For HRs of 60 to 72 beats/min, motion artifacts were significantly lower for diastole (1.6 ± 0.3) than systole (1.8 ± 0.4) (P < .001), and vice versa for HRs of 73 to 84 beats/min (1.7 ± 0.3 for systole vs 2.0 ± 0.5 for diastole, P < .01).
Optimal systolic and diastolic reconstruction intervals were determined for this 256-slice coronary computed tomographic angiographic study. Combined reconstruction showed fewer motion artifacts compared to single-phase reconstruction. In conclusion, 256-slice computed tomography has the potential to improve the diagnostic accuracy of coronary computed tomographic angiography.
本研究旨在确定 256 层 CT 冠状动脉 CT 血管造影（CCTA）收缩期和舒张期的最佳图像重建时相，并评估其相关运动伪影。
共纳入 126 例患者（平均心率[HR]为 72.1 次/分；HR 变异性为 1.3 次/分）。20 组数据以 5%的步长重建，范围为 0%至 95%的 RR 间期。两名观察者根据运动伪影，对 3 支冠状动脉的 15 个节段的最佳重建时相进行区分，运动伪影评分范围为 1（无运动伪影）至 4（严重运动伪影导致诊断困难）。然后，根据 HR 与运动评分的相关性分析结果，将患者分为 4 个 HR 组，比较运动评分。
最佳收缩期和舒张期重建时相分别为 44.4%±3.8%和 77.4%±3.7%。收缩期、舒张期和收缩期+舒张期（S+D）重建的平均运动评分分别为 1.8±0.3、1.8±0.5 和 1.5±0.3。与单时相重建相比，S+D 重建可将诊断可评估性提高至 100%，且在所有 HR 范围内（S+D 比收缩期，HR＜85 次/分，P＜0.05；S+D 比舒张期，HR 为 73-84 次/分，P＜0.05）运动伪影均较少。对于 HR 为 60-72 次/分，舒张期（1.6±0.3）的运动伪影明显低于收缩期（1.8±0.4）（P＜0.001），而 HR 为 73-84 次/分时则相反（收缩期 1.7±0.3 比舒张期 2.0±0.5，P＜0.01）。
本 256 层 CCTA 研究确定了最佳的收缩期和舒张期重建时相。与单时相重建相比，联合重建可减少运动伪影。总之，256 层 CT 有可能提高 CCTA 的诊断准确性。
