第二代双源CT冠状动脉成像前门控大螺距扫描的初步经验  

The preliminary clinical experience of the coronary angiography using the second generation Dual-source CT in prospectively ECG-gated high-pitch mode

作　　者：赵青[1] 佟海滨[1] 王小玲[1] 薛超[1] 张民[1] 杨树华[1] 王群[1] 汪平[1] 石凤祥[1] 徐磊[2] 于薇[2] 方继良[1] 

机构地区：[1]中国中医科学院广安门医院放射科,北京100053 [2]首都医科大学附属北京安贞医院影像医学科,北京100029

出　　处：《中国中西医结合影像学杂志》2011年第4期299-302,321,F0002,共6页Chinese Imaging Journal of Integrated Traditional and Western Medicine

摘　　要：目的:初步分析第二代双源CT前瞻性心电触发大螺距扫描(Flash模式)行心脏冠状动脉成像的图像质量,同时观察扫描的辐射剂量。方法:回顾性分析了87例第二代双源CT使用Flash扫描模式(前瞻性心电触发选在60%R-R间期,螺距3.4)行冠脉成像患者的图像质量。分别由2名医师采用4级法进行综合评估,1～3级图像为可评估,能用于影像诊断,4级为不可评估;根据美国心脏学会冠脉16段分段法,对各段图像质量进行分级评估;再根据扫描心率,分成≤65次/min和>65次/min2组病例,比较2组间图像质量的差异;统计分析此种扫描模式的平均辐射剂量。结果:共评价冠脉1047段,可用于诊断的节段占97.3%,不可评价节段占2.7%;平均心率≤65次/min组可评价血管节段为99.5%,平均心率>65次/min组可评价血管节段是89.1%,2组图像质量差异有统计学意义(P<0.05)。平均每例扫描辐射剂量为(1.25±0.45)mSv。结论:使用Flash模式行冠脉CTA扫描图像质量较高;对于心律较整齐患者,影响其图像质量的主要因素是心率,在60%R-R间期采集时,扫描时心率≤65次/min图像质量较心率>65次/min可评价比例明显提高;此种模式较其他扫描模式辐射剂量显著降低。Objective： To evaluate the image quality and radiation exposure of the coronary angiography using the second generation Dual-source CT in prospectively ECG-gated high-pitch mode （Flash mode）. Methods： Eighty-seven patients with suspec- ted coronary artery disease were imaged on a second generation DSCT scanner using flash mode. Data acquired was prospectively ECG-triggered at 60% of the R-R interval with a pitch of 3.4. Coronary arteries were segmented in 16 sections according to the guideline of the American Heart Association （AHA）. Two radiologists assessed image quality of all coronary segments using 4 point grading scales. All patients were divided into two groups according to their HR （heart rate）： group A HR≤65 bmp, group B HR〉65 bmp. The image quality was compared between two groups. The average radiation dose was calculated for every patient. All statistical analysis was performed with SPSS 13.0. Results： A total of 1047 coronary artery segments were evaluated. The diagnostic （scores 1-3） image quality was in 97. 3% of the segments, and non-assessable （score 4） in 2.7%. The assessable coronary segments in Group A were 781 （99.5%）; however, that in Group B were 237（89.1%）. The significant difference existed between the two groups （P〈0.05）. The mean effective dose was （1.25 ± 0.45）mSv. Conclusions： Flash mode provides excellent image quality with low radiation exposure. HR is the important element for the image quality.

关 键 词：第二代双源CT 前瞻性心电触发大螺距扫描 冠状动脉成像 辐射剂量 

分 类 号：R816.2[医药卫生—放射医学]