64层CT盆腔动脉成像质量及辐射剂量的研究  

Optimized imaging quality and radiation dose for pelvic angiography using 64-slice CT

作　　者：陈锋[1] 潘旭红[1] 崔程凯 隋旭蕾 唐小锋[1] 

机构地区：[1]山东省烟台市烟台山医院影像科,山东烟台260001

出　　处：《医学影像学杂志》2014年第2期279-282,共4页Journal of Medical Imaging

基　　金：烟台市科技发展计划项目(编号:2010149-3)

摘　　要：目的初步探讨64层CT盆腔动脉成像中低mAs技术应用价值,评价其图像质量和辐射剂量。方法选取50例日常盆腔增强检查患者随机分为A、B 2组,A组24例使用250mAs进行CT盆腔动脉成像,B组26例使用100mAs。通过CT机自动得到CT剂量指数(CT dose index,CTDI)和剂量长度乘积(dose length product,DLP)。对2组扫描数据分别进行多种图像后处理,2名有经验的影像科医师采用双盲法评价图像质量,测量噪声及CT值。两组图像ROI的CT值、噪声、SNR、辐射剂量及图像质量评分用两独立样本t检验进行统计分析。2名医师评分一致性采用Kappa检验。结果 A组盆腔动脉分支图像质量评分为2.9±0.1,B组为2.8±0.1,2组之间比较差异无统计学意义(P>0.05)。A组CTDI、DLP和ED分别为14.7、458.5±13.3和8.7±0.3,而B组分别为6.4、179.9±8.9和3.4±0.2,2组CTDI、DLP和ED之间比较差异有统计学意义(P<0.05)。2组间髂内动脉平均SNR差异有统计学意义。A组评价144分支,B组评价156分支,A、B组优良者分别达到100%和98.1%。结论低mAs盆腔动脉扫描可在保证图像质量的同时显著降低辐射剂量。Objective To evaluate the image quality and the radiation dose in 64-slice CT pelvic angiography by using low mAs mode. Methods Fifty patients who underwent pelvic angiography on a 64-slice CT scanner were randomized two groups （group A and group B）. Twenty-four patients in group A were examined with 250 mAs, and twenty-six patients in group B with 150 mAs. The CTDI value and DLP value were automatically recorded by CT scanner. All images were transferred to a workstation for further processing and analysis. Two observers blinded to clinical data independently as- sessed the image quality, and measured the image noise, signal-to-noise ratio （SNR） and CT values. The CT value, ima- ging noise, SNR, radiation dose and imaging quality scores were compared between the two groups with t test. The inter- obverser agreement was determined by Kappa statistics. Results The mean score of imaging quality for pelvic artery bran- ches in group A was 2.9 ± 0.1 and that in group B was 2.8 ~ 0.1, there was no statistical difference in imaging quality be- tween the two groups （ P 〉0.05）. The CTDI, DLP and ED were 14.7, 458.5±13.3 and 8.7±0.3 respectively in the group A, whereas, 6.4, 179.9±8.9 and 3.4±0.2 in group B, there was a statistical difference between the two groups. The mean SNR of the internal iliac artery was 15. 1± 0.7 in group A and 12.3 ± 1.3 in group B, there was statistical difference in SNR of the internal iliac artery between the two groups. A total of 144 pelvic artery branches were evaluated in group A and 156 branches were evaluated in group B, excellent or good was achieved in 100% and 98.1% in A and B group, respectively. Conclusion The low mAs pelvic angiography scanning can substantially reduce radiation while pre- serving good imaging quality.

关 键 词：盆腔血管 体层摄影术 X线计算机 辐射剂量 

分 类 号：R543.5[医药卫生—心血管疾病] R814.42[医药卫生—内科学]