Department of Diagnostic Imaging, Monash Medical Centre, Southern Health, Clayton, Victoria 3168, Australia.
AJR Am J Roentgenol. 2009 Dec;193(6):1514-21. doi: 10.2214/AJR.09.2319.
Noninvasive coronary angiography has generally been contraindicated in patients with atrial fibrillation because of the difficulty in synchronizing an irregular heartbeat with table gantry movement. The objective of this study was to evaluate and compare the quality of 320-MDCT images obtained in patients with atrial fibrillation and in a control group of patients in sinus rhythm.
Two reviewers were blinded to the patient groups and evaluated images of 15 coronary artery segments for each patient using 320-MDCT. The images were printed on glossy paper and scored subjectively as 1 or 2, meaning of diagnostic quality, or 3, meaning poor quality.
No statistical difference between the groups was noted in patient age: The mean age of the patients with atrial fibrillation was 67 years (age range, 52-82 years) and that of the patients in sinus rhythm was 59 years (36-86 years) (p = 0.3). Scores of 1 and 2 (diagnostic quality) were assigned to 100% in sinus rhythm and 96% in atrial fibrillation (p < 0.05). Scores of 3 were seen only in the atrial fibrillation group (7/175, 4%). Segment 15, the distal circumflex artery, was the segment that was most frequently assigned a score of 3 (2/7, 28.6%). A discrepancy in the two reviewers' scores was seen in 25 segments (7%), requiring joint consensus. The segments that most frequently required consensus reading were segments 12 and 15. The overall mean image quality score for all three coronary arteries in atrial fibrillation was 1.25 +/- 0.47 (SD) and 1.08 +/- 0.26 in sinus rhythm (p < 0.001). The median effective dose was 19.28 and 13.55 mSv in the atrial fibrillation and sinus rhythm groups, respectively.
The analysis of our initial experience shows that imaging in patients with atrial fibrillation is possible using 320-MDCT, with images of most segments obtained being of diagnostic quality. Segment 15 was the most difficult to see on 320-MDCT because of the small caliber of the vessel; poor visualization of that segment mostly occurred in the setting of a dominant right coronary arterial system.
由于难以将不规则心跳与台架运动同步，非侵入性冠状动脉造影术一般不应用于房颤患者。本研究旨在评估和比较房颤患者与窦性心律患者的 320-MDCT 图像质量。
两位观察者对患者分组情况不知情，使用 320-MDCT 对每位患者的 15 个冠状动脉节段进行图像评估。将图像打印在光面纸上，并根据诊断质量对其进行主观评分 1 或 2，或评分 3 表示质量差。
两组患者的年龄无统计学差异：房颤患者的平均年龄为 67 岁（年龄范围为 52-82 岁），窦性心律患者的平均年龄为 59 岁（36-86 岁）（p = 0.3）。窦性心律组评分 1 和 2（诊断质量）的比例为 100%，房颤组为 96%（p < 0.05）。仅在房颤组中观察到评分 3（7/175，4%）。节段 15，即远侧回旋支，是评分 3 最常见的节段（2/7，28.6%）。两位观察者的评分有 25 个节段（7%）存在差异，需要共同协商。最需要共识阅读的节段是 12 号和 15 号。房颤患者所有三支冠状动脉的总体平均图像质量评分为 1.25 +/- 0.47（SD），窦性心律组为 1.08 +/- 0.26（p < 0.001）。房颤组和窦性心律组的有效剂量中位数分别为 19.28 和 13.55 mSv。
根据我们的初步经验分析，使用 320-MDCT 对房颤患者进行成像，大多数节段的图像质量可达到诊断要求。由于血管直径较小，节段 15 是最难以在 320-MDCT 上看到的；由于右冠状动脉优势，该节段的可视化效果较差。
