比较不同体型特异性剂量评估算法在估算成人胸腹部CT扫描中辐射剂量的差异  

Comparison of different SSDE methods in evaluating the radiation dose in chest and abdomen CT scan

作　　者：袁子龙[1] 王国柱[2] 张照喜[1] 郑丽丽[1] 杜东屏[1] 陈迢 彭伟[1] 邱建峰[2] 刘玉林[1] 

机构地区：[1]湖北省肿瘤医院放射科,武汉430079 [2]泰山医学院放射学院,泰安271016

出　　处：《中华放射医学与防护杂志》2016年第11期852-856,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：科技部国家重点专项计划项目（2016YFC0103400）

摘　　要：目的 比较基于水等效直径（WED）的体型特异性剂量评估（SSDEWED）和基于有效直径（ED）的SSDEED在估算成人胸腹部CT辐射剂量中的差异。方法 采用德国西门子SOMATOM Definition AS 64排128层CT机对240例成人患者行胸部（161例）、腹部（79例）平扫，按部位分别分为胸部A组左右径（LAT）〈30 cm，B组30 cm≤LAT≤34 cm，C组LAT〉34 cm和腹部A组LAT〈27cm，B组27 cm≤LAT≤32 cm，C组LAT〉32 cm。记录每例患者的CTDIvol值，并计算ED、WED和转换系数fsize，以及患者的SSDEED和SSDEWED。比较不同LAT组SSDEWED和SSDEED之间的差异。结果 胸部扫描患者ED与WED、fsize，ED与fsize，WED及SSDEED与SSDEWED之间差异均有统计学意义（t=-33.12、32.55、28.44，P〈0.05），3组病例间LAT、ED、WED、SSDEED和SSDEWED 差异均有统计学意义（F=273.67、140.97、77.05、19.87、32.21，P〈0.05）；腹部扫描患者ED与WED、fsize，ED与fsize，WED及SSDEED与SSDEWED之间差异均有统计学意义（t=-24.09、-22.96、22.46，P〈0.05），3组病例间LAT、ED、WED、SSDEED和SSDEWED差异均有统计学意义（F=123.89、82.17、83.16、52.74、53.62，P〈0.05）。胸部WED较ED降低约12.0%，导致SSDEWED较SSDEED增加了约11.6%；腹部WED较ED增加了约5.2%，导致SSDEWED较SSDEED降低了约4.8%，且胸部及腹部3组病例SSDEWED较SSDEED均随着LAT的增加而增加。结论 WED能够更好地代表患者的体型大小及衰减特性，SSDEWED能够更准确地计算胸腹部CT患者的辐射剂量。Objective To compare the difference between SSDEED and SSDEWED in evaluating the radiation dose of adult chest and abdomen CT scans. Methods A total of 240 adult patients were performed CT scan for chest or abdomen by Siemens 128 slice CT （161 cases in chest, 79 cases in abdomen）, and they were divided into three groups according to the different left-right （LAT） sizes of chest and abdomen （for chest, group A, LAT〈30 cm;group B, 30 cm≤LAT≤34 cm;group C, LAT〉34 cm;for abdomen, group A, LAT〈27 cm; group B, 27 cm≤LAT≤32 cm; group C, LAT〉32 cm）. The images of middle scanning volume were chosen and measured in elliptic ROIs. The ED, WED and conversion coefficient were calculated, and SSDEED and SSDEWED were calculated by CTDIvol. The difference between SSDEED and SSDEWED in different LAT groups were compared. Results For chest CT, the difference between ED and WED, fsize, ED and fsize, WED, SSDEED and SSDEWED had statistical significance（t=-33.118, 32.552, 28.435, P〈0.05）. The LAT, ED, WED, SSDEED and SSDEWED between 3 groups also had significant difference （F=273.67, 140.97, 77.05, 19.87, 32.21, P〈0.05）. For abdomen CT, all parameters had statistically significant difference（t=-24.086, -22.960, 22.457, P〈0.05）. The LAT, ED, WED, SSDEED and SSDEWED in 3 groups were obviously different （F=123.89, 82.17, 83.16, 52.74, 53.62, P〈0.05）. Compared with ED, the WED in chest decreased by 12.0%, resulting in SSDEWED increasing about 11.6%. The WED in abdomen increased about 5.2%, resulting in SSDEWED decreasing about 4.8%. Conclusions The WED can represent preferably the size and attenuation characteristics of the patient, and the SSDEWED can be used to accurately evaluatethe patient radiation dose in chest and abdomen CT scanning.

关 键 词：有效直径 水等效直径 体型特异性剂量评估 

分 类 号：R816[医药卫生—放射医学]