Department of Diagnostic Imaging, Monash Medical Centre, Southern Health, 246 Clayton Rd, Clayton, Victoria 3168, Australia.
AJR Am J Roentgenol. 2011 Jun;196(6):W729-35. doi: 10.2214/AJR.10.5252.
High heart rate may negatively influence the image quality of cardiac CT. The technical advances of 320-MDCT may overcome issues with poor image quality associated with high heart rate. This study aimed to evaluate the coronary image quality of 320-MDCT in patients with heart rates above 65 beats/min.
Patients who presented for cardiac CT were divided into two groups according to heart rate, either greater than 65 beats/min or less than or equal to 65 beats/min. Two radiologists were blinded to the patient groups and evaluated images of 15 coronary artery segments per patient using 320-MDCT with consensus agreement. The image quality was scored subjectively as 1 or 2 (diagnostic quality) or 3 (poor quality and nondiagnostic).
There were no statistically significant differences between the two groups in terms of age, sex, and body mass index (p > 0.05). The median heart rate was 70 beats/min (range, 67-110 beats/min) for the group with heart rate greater than 65 beats/min and 60 beats/min (range, 48-65 beats/min) for the group with heart rate less than or equal to 65 beats/min (p < 0.001). In patients with heart rates greater than 65 beats/min, diagnostic quality images (scores of 1 or 2) were obtained in 95.6% of the analyzed segments, compared with 96.9% in the group with heart rate less than or equal to 65 beats/min (p = 0.7).
Our initial evaluation suggests that coronary artery images of diagnostic quality can be obtained using 320-MDCT in most patients with heart rates greater than 65 beats/min, in percentages similar to those for patients with heart rates less than or equal to 65 beats/min. This finding may be the result of the inherent image acquisition and reconstruction technique of 320-MDCT.
心率过快可能会影响心脏 CT 的成像质量。320 层 MDCT 的技术进步可能克服与心率过快相关的成像质量差的问题。本研究旨在评估心率高于 65 次/分时 320 层 MDCT 的冠状动脉图像质量。
根据心率将接受心脏 CT 的患者分为两组，心率大于 65 次/分或心率等于或小于 65 次/分。两名放射科医生对患者的 15 个冠状动脉节段的图像进行盲法评估，使用 320 层 MDCT 进行评估，结果以 1 或 2（诊断质量）或 3（质量差且不可诊断）进行评分。
两组在年龄、性别和体重指数方面无统计学差异（p＞0.05）。心率大于 65 次/分组的中位数心率为 70 次/分（范围，67-110 次/分），心率等于或小于 65 次/分组的中位数心率为 60 次/分（范围，48-65 次/分）（p＜0.001）。在心率大于 65 次/分的患者中，95.6%的分析节段获得了诊断质量的图像（评分 1 或 2），而心率等于或小于 65 次/分组为 96.9%（p=0.7）。
我们的初步评估表明，在大多数心率大于 65 次/分的患者中，使用 320 层 MDCT 可以获得诊断质量的冠状动脉图像，其百分比与心率等于或小于 65 次/分的患者相似。这一发现可能是 320 层 MDCT 的固有图像采集和重建技术的结果。
