Meyer Mathias, Haubenreisser Holger, Schoepf Uwe Joseph, Vliegenthart Rozemarijn, Ong Melissa M, Doesch Christina, Sudarski Sonja, Borggrefe Martin, Schoenberg Stefan O, Henzler Thomas
Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3 D-68167 Mannheim, Germany; DZHK (German Centre for Cardiovascular Research) partner site Mannheim, Germany.
Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3 D-68167 Mannheim, Germany; DZHK (German Centre for Cardiovascular Research) partner site Mannheim, Germany.
Acad Radiol. 2017 Jan;24(1):30-37. doi: 10.1016/j.acra.2016.08.004. Epub 2016 Oct 28.
Despite ongoing technical refinements, coronary computed tomography angiography (cCTA) remains challenging in its diagnostic value by electrocardiographic (ECG) misregistration and motion artifacts, which commonly occur in patients with atrial fibrillation and high or irregular heart rates. The aim of this study was to evaluate the radiation dose and the number of inconclusive coronary segments at cCTA using retrospective ECG gating at 100 and 70 kV.
With institutional review board approval, 154 patients (median age 54 years, 98 men) with high or irregular heart rate prospectively underwent retrospectively ECG-gated cCTA without tube current modulation on a third-generation dual-source computed tomography (DSCT) system at 70 kV (n = 103) or on a second-generation DSCT system at 100 kV (n = 51). Images were reconstructed in best diastolic phase (BDP), best systolic phase (BSP), and in all phases (APs) at 10% intervals across the R-R cycle. Objective and subjective image qualities were evaluated as well as the presence of motion artifacts with the three different reconstruction approaches.
The mean heart rate was 93 ± 16 bpm. The mean effective radiation dose was 4.5 mSv for 70 kV compared to 8.4 mSv for 100 kV (P < 0.05). At BDP reconstruction, 71% (n = 110) of the patients showed motion artifacts in one or more coronary segments. At BSP reconstruction, the number of patients with motion artifacts decreased to 37% (n = 57). In contrast, if images were reconstructed with the AP approach, all vessels and coronary segments were evaluable with both cCTA protocols.
Retrospectively ECG-gated cCTA at 70 kV results in 52% decreased radiation dose. Further using the AP algorithm allowed for diagnostic evaluation of all coronary segments for stenosis, in contrast to BDP or BSP phase alone.
尽管技术不断改进，但冠状动脉计算机断层扫描血管造影（cCTA）在诊断价值方面仍面临挑战，原因在于心电图（ECG）配准错误和运动伪影，这些情况在心房颤动以及心率高或不规则的患者中很常见。本研究的目的是评估在100 kV和70 kV下使用回顾性心电图门控的cCTA的辐射剂量和不确定的冠状动脉节段数量。
经机构审查委员会批准，154例心率高或不规则的患者（中位年龄54岁，98例男性）前瞻性地接受了回顾性心电图门控的cCTA检查，在第三代双源计算机断层扫描（DSCT）系统上于70 kV（n = 103）或第二代DSCT系统上于100 kV（n = 51）进行，未进行管电流调制。图像在舒张末期最佳相位（BDP）、收缩末期最佳相位（BSP）以及整个心动周期以10%间隔的所有相位（APs）进行重建。评估了三种不同重建方法下的客观和主观图像质量以及运动伪影的存在情况。
平均心率为93±16次/分钟。70 kV时的平均有效辐射剂量为4.5 mSv，而100 kV时为8.4 mSv（P < 0.05）。在BDP重建时，71%（n = 110）的患者在一个或多个冠状动脉节段出现运动伪影。在BSP重建时，出现运动伪影的患者数量降至37%（n = 57）。相比之下，如果采用AP方法重建图像，两种cCTA方案均可评估所有血管和冠状动脉节段。
70 kV下的回顾性心电图门控cCTA可使辐射剂量降低52%。与单独的BDP或BSP相位相比，进一步使用AP算法可对所有冠状动脉节段进行狭窄的诊断评估。
