Comparison of Prospective and Retrospective Electrocardiogram-triggered Coronary CT Angiography Using Dual-source CT
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摘要:
目的 比较前瞻性心电触发序列扫描与回顾性心电触发螺旋扫描模式在双源CT冠状动脉成像中的图像质量及放射线剂量。 方法 将70例临床怀疑或已知冠心病的患者随机分为两组, 每组35例, 分别行前瞻性心电触发序列扫描和回顾性心电触发螺旋扫描冠状动脉CT成像, 对两种成像模式的图像质量及放射线剂量进行评价。 结果 两组患者的性别、年龄、体重指数匹配性良好, 差异无统计学意义(P > 0.05)。前瞻性心电触发序列扫描模式组和回顾性心电触发螺旋扫描模式组可评价的冠状动脉节段显示率分别为99.62%和99.62%, 两组间差异无统计学意义(χ2=0.000, P=1.000);两组图像质量评分分别为1.13±0.36和1.04±0.24, 差异有统计学意义(Z=-5.073, P=0.000);前瞻性心电触发序列扫描模式的放射线剂量为(3.47±1.00)mSv, 明显低于回顾性螺旋扫描模式的(14.28±1.81)mSv(P=0.032)。 结论 对于心律齐且心率≤ 70次/min的患者, 尽管前瞻性心电触发序列扫描的图像质量略差于回顾性螺旋扫描模式, 但两者可评价的冠状动脉节段显示率无明显差异, 而前者的有效放射剂量明显减少。 -
关键词:
- 冠状动脉成像 /
- X线计算机体层摄影术 /
- 影像质量 /
- 放射剂量
Abstract:Objective To compare the image quality and radiation exposure of prospective electrocardiogram (ECG) -triggered sequential and retrospective spiral acquisition coronary CT angiography by dual-source CT. Methods Seventy patients with suspected or known coronary artery disease were randomly divided into two groups (n=35). Group A underwent prospective ECG-triggered sequential scan and group B underwent retrospective ECG-triggered spiral scan. The image quality and radiation exposure of both modes were evaluated. Results There was no significant difference in gender, age, or body mass index between the two groups (P > 0.05). The rates of diagnostic coronary segments for group A and group B were 99.62% and 99.62%, respectively (χ2=0.000, P=1.000). The average image quality score was 1.13±0.36 in group A and 1.04±0.24 in group B, with significant difference between the two groups (Z=-5.073, P=0.000). The mean radiation dose of group A was significantly lower than that of group B[(3.47±1.00) mSv vs. (14.28±1.81) mSv, P=0.032]. Conclusion The prospective ECG-triggered sequential scan coronary CT angiography technique significantly reduces radiation dose without impairing the rates of diagnostic coronary segments when compared with the retrospective ECG-triggered spiral data acquisition in patients with a low and stable heart rate (≤ 70 bpm). -
Key words:
- coronary angiography /
- X-ray computed tomography /
- image quality /
- radiation exposure
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表 1 前瞻组与回顾组扫描参数的比较
组别 扫描方式 准直(mm) 采集层数(层) 机架旋转时间(s) 时间分辨率(ms) 管电压(kV) 管电流(mAs/转) 螺距 重建时相选择 前瞻组 序列扫描 32 × 0. 6 2 × 64 0. 33 83 120 371 无 70%时相 回顾组 螺旋扫描 32 × 0. 6 64 0. 33 83 120 400 0. 22 ~ 0. 33 35% ~ 75%时相 表 2 前瞻组与回顾组临床资料的比较(x ± s)
组别 性别(男/女) 年龄(岁) 体重指数(kg /m2) 扫描时心率(次/min) 扫描时间(s) 扫描时管电流(mAs/转) 前瞻组 19 /16 58. 7 ± 9. 1 24. 4 ± 2. 6 59. 9 ± 5. 8 0. 38 286. 06 ± 70. 69 回顾组 19 /16 59. 7 ± 11. 7 25. 6 ± 3. 1 61. 5 ± 4. 3 9. 98 ± 1. 12 400 表 3 前瞻组与回顾组放射剂量的比较(x ± s)
组别 CT容积剂量指数(mGy) 剂量长度乘积(mGy·cm) 有效放射剂量(mSv) 前瞻组 18. 45 ± 4. 55 247. 70 ± 71. 40 3. 47 ± 1. 00 回顾组 67. 78 ± 6. 64 1019. 77 ± 129. 27 14. 28 ± 1. 81 P值 0. 027 0. 032 0. 032 -
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