128层MSCT低剂量技术在冠状动脉成像的应用研究

目的:探讨128层多层螺旋CT低剂量扫描技术在冠状动脉成像中的应用价值。方法:选择120例,心率控制在80次/min以下,且心律齐的受检者。随机等分为2组,组1为低剂量组(100kV),组2为常规剂量组(120kV),分别统计两组机器自动得到的平均容积CT剂量权重指数(CTDIvol)和剂量长度乘积(DLP),并计算出相应的有效辐射剂量(ED)。获得的图像通过双盲法由两位副高放射诊断医师对图像质量进行评分,按10段评分法进行评分,并记录评分结果;对两组CTDIvol值、ED值和图像质量评分进行统计学处理。结果:组1和组2的CTDIvol值分别为11.35mGy±1.2mGy和22.82mGy±2.3mGy,ED值分别为2.62mSv±1.4mSv和5.27mSv±2.0mSv;两组的CTDIvol值及ED值的比值分别为49.7%和49.7%,两者之间差异均有统计学意义(P值均<0.01)。两组图像质量均符合临床诊断要求,图像差异无统计学意义(P>0.05)。结论:128层螺旋CT低剂量(100kV)冠状动脉成像技术既能有效降低受检者的辐射剂量同时又能保证图像质量,值得临床推广应用。

Application Study of Low-dose 128-Slice Spiral CT Coronary Artery Angiography

Objective:To evaluate the value of low-dose scanning with 128-slice CT coronary artery angiography. Methods:120 patients, heart rate<80 bpm, regular rhythm, were randomly divided into two groups. The first group was 60 patients with low-dose (100 kV) scanning, the second group was 60 patients with conventional dose (120 kV) scanning. Volume computed tomography dose index (CTDIvol) and dose-length product (DLP) were automatically obtained by CT scanning, and effective dose (ED) were obtained by calculating. Two associate chief physicians review the CT images independently. Two groups were evaluated for image quality score (10 segments, each coronary artery segment, 4-point scale) and radiation dose, A p value below 0.05 was considered statistically significant. Results:The mean CTDIvol for the first group was 11.35 mGy ±1.2 mGy, the mean ED was 2.62 mSv ±1.4 mSv, and the mean CTDIvol for the second group was 22.82 mGy ±2.3 mGy, the mean ED was 5.27 mSv ±2.0 mSv, The ratio of CTDIvol and DLP for two groups were 49.7%, 49.7% respectively, the two groups difference were statistically significant (P<0.05).The mean image quality score for two groups were not statistically significant (P>0.05). Conclusion:Low-dose scanning of 128-slice spiral CT can maintain highest image quality while reducing the radiation dose (100 kV) in coronary artery angiography. This technique is suitable for promote in clinical.