摘要
目的:评价低管电压及短重叠时间联合设置措施在前瞻性心电门控冠状动脉CT血管成像(CCTA)中的应用价值。方法:选取拟行CCTA检查的受检者80例,心率(HR)<65次/分、心率变异(HRv)<5次/分、体质量指数(BMI)≤24kg/m2。将受检者随机分为A、B两组进行前门控CCTA检查,A组管电压设置为120kV,管电流400mA,重叠时间(PT)100ms,B组管电压设置为100kV,管电流400mA,PT 50ms。采用SPSS 13.0软件包对A、B两组的图像质量及辐射剂量进行统计学分析,检验水准α=0.05。结果:A、B两组冠脉主观评分差异具有统计学意义(Z=-8.534,P<0.00001),而可用于诊断的冠脉节段比例的差异无统计学意义(χ2=0.677,P=0.411);A、B两组主动脉根部平均衰减值、噪声值、信噪比及对比度噪声比差异均具有统计学意义(P均<0.05);A、B两组平均辐射剂量分别为(3.35±0.49)和(1.57±0.23)mSv,且差异有统计学意义(t=20.084,P<0.00001)。结论:低管电压及短PT联合措施在前门控CCTA中可获得满足诊断需求的图像,且辐射剂量大幅降低。
Objective：To evaluate image quality and radiation dose for coronary artery computed tomographic angiog raphy （CTA） obtained with low tube voltage and short padding time setting for a prospectively gated axial （PGA） CT technique at low heart rate （HR） and heart rate variation （HRv）. Methods： Eighty patients enrolled in this study were randomly divided into two groups. Group A consisted of 40 patients with average body mass index（BMI） 20. 12 using PGA scan technique （tube voltage was 120kV and tube current was 400mA）. Image acquisition was performed at 75 % of the R-R interval, and the padding time setting was 100ms. Group B consisted of 40 patients with BMI 20.42 using PGA scan technique （tube voltage was 100kV and tube current was 400mA）. Image acquisition was performed at 75% of the RR interval,and the pad ding time setting was 50ms. The two groups were evaluated for image quality, mean attenuation, noise, signal-to-noise ratio （SNR） ,contrast-to-noise （CNR） in aortic root and radiation dose. Image quality and radiation dose were analyzed by Mann Whitney U-test and unpaired t test. A P value below 0.05 was considered to be statistically significant. Results： The mean effective dose,being statistically significant, for Group A was 3. 35mSv versus 1. 57mSv for Group B （t= 20. 084, P〈 0. 00001）. The mean image quality score was 4.69 for Group A versus 4.37 for Group B （Z=-8. 534,P%0. 00001）. The mean attenuation, noise, SNR and CNR were statistically significant for group A versus group B （P〈0.05）. The percentage of assessable coronary artery segments was not statistically significant for group B versus group A （X2 = 0. 677, P= 0.411 ）. Conclusion： Low tube voltage and short padding time setting for PGA CT technique could offer assessable image quality and substantially reduced effective radiation close at low HR and HRv.
出处
《放射学实践》
2013年第2期159-162,共4页
Radiologic Practice
基金
内蒙古财政厅科研项目(NC20080018)
内蒙古高等学校科学研究项目(NJZY07091)
