摘要
目的探讨容积CT剂量指数(CTDIvol)与体型特异性剂量估算(SSDE)两种辐射剂量估算方法在评估成人胸部CT扫描辐射剂量中的应用价值.方法回顾性分析2017年3月至4月浙江中医药大学附属第一医院128例进行胸部CT平扫且所有图像均能满足诊断要求的受检者的CTDIvol与SSDE.将受检者按照不同体质量指数(BMI)分为3组:A组,16≤BMI<21.1kg/m2,38例;B组,21.1≤BMI<23.9kg/m2,53例;C组,23.9≤BMI<34.1kg/m2,37例.在两乳头层面测量每例受检者的前后径(AP)、左右径(LAT),记录每例受检者的CTDIvol值,计算每例受检者的有效直径(ED)、转换因子(fsize)和SSDE.同时,比较不同体质量指数组CTDIvol与SSDE之间的差异.结果3组受检者的SSDE均高于CTDIvol,A、B、C组分别增加了50.13%、42.83%、33.68%.CTDIvol和SSDE估算方法3组辐射剂量比较差异均有统计学意义(t=-48.873、-57.001、-32.651,P<0.05).3组受检者间的ED、fsize、CTDIvol和SSDE差异均有统计学意义(F=51.456、47.749、113.916、106.449,P<0.05).结论SSDE能够评估不同体型的受检者在胸部CT扫描中所受到的辐射剂量,而CTDIvol过低地估计了受检者受到的辐射剂量,且BMI越小的受检者被低估的剂量值越大,实际受到的辐射剂量越多.
Objective To investigate the application value of CTDIvol and size-specific dose estimate(SSDE) in evaluating the radiation dose of adult chest CT. Methods A retrospective analysis was made on the CTDIvol and SSDE of 128 patients who underwent chest CT scanning in the First Affiliated Hospital of Zhejiang Chinese Medical University from March to April 2017 and all images are adequate for diagnosis. The subjects were divided into three groups according to body mass index (BMI):Group A, 38 cases with 16 ≤ BMI < 21.1 kg/m2;Group B, 53 cases with 21.1 ≤ BMI < 23.9 kg/m2;Group C, 37 cases with 23.9 ≤ BMI < 34.1 kg/m2. The diameters of anterior-posterior (AP) and left-right (LAT) of each patient were measured in the slice of nipple level, and CTDIvol, effective diameter (ED), conversion factor (fsize) and SSDE of each patient were recorded and calculated. Meanwhile, the differences between CTDIvol and SSDE in different BMI groups were compared. Results SSDE of each group was higher than CTDIvol, and increased by 50.13%, 42.83% and 33.68% in group A, B and C, respectively. There were significant differences in radiation dose between CTDIvol and SSDE in the three groups (t=-48.873,-57.001,-32.651, P < 0.05). There were significant differences in ED, fsize, CTDIvol and SSDE among the three groups (F=51.456, 47.749, 113.916, 106.449, P < 0.05). Conclusions SSDE can evaluate the radiation dose absorbed by patients with different body types in chest CT, while CTDIvol underestimated the radiation dose.The lower BMI, the greater the underestimated dose value, the more radiation dose absorbed.
作者
王军娜
王世威
徐志超
凌东亚
卜阳阳
Wang Junna;Wang Shiwei;Xu Zhichao;Ling Dongya;Bu Yangyang(Department of Radiology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310006, China)
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2019年第9期711-714,共4页
Chinese Journal of Radiological Medicine and Protection
