Boos Johannes, Kröpil Patric, Bethge Oliver Th, Aissa Joel, Schleich Christoph, Sawicki Lino Morris, Heinzler Niklas, Antoch Gerald, Thomas Christoph
Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Moorenstraße 5, 40 225 Düsseldorf, Germany.
Radiat Prot Dosimetry. 2018 Jan 1;178(1):8-19. doi: 10.1093/rpd/ncx069.
To evaluate the accuracy of size-specific dose estimate (SSDE) calculation from center slice with water-equivalent diameter (Dw) and effective diameter (Deff). A total of 1812 CT exams (1583 adult and 229 pediatric) were included in this retrospective study. Dw and Deff were automatically calculated for all slices of each scan. SSDEs were calculated with two methods: (1) from the center slice; and (2) from all slices of the volume, which was regarded as the reference standard. Impact of patient weight, height and body mass index (BMI) on SSDE accuracy was assessed. The mean difference between overall SSDE and the center slice approach ranged from 2.0 ± 1.7% (range: 0-15.5%) for pediatric chest to 5.0 ± 3.2% (0-17.2%) for adult chest CT. Accuracy of the center slice SSDE approach correlated with patient size (BMI: r = 0.15-0.43; weight r = 0.26-0.49) which led to SSDE overestimation in small and underestimation in large patients. SSDE calculation using the center slice leads to an error of 2-5%; however, SSDE is underestimated in large patients and overestimation in small patients.
评估根据水等效直径(Dw)和有效直径(Deff)通过中心层面计算特定尺寸剂量估计(SSDE)的准确性。本回顾性研究共纳入1812例CT检查(1583例成人和229例儿童)。对每次扫描的所有层面自动计算Dw和Deff。采用两种方法计算SSDE:(1)根据中心层面;(2)根据容积的所有层面,后者被视为参考标准。评估患者体重、身高和体重指数(BMI)对SSDE准确性的影响。总体SSDE与中心层面法之间的平均差异,儿童胸部为2.0±1.7%(范围:0-15.5%),成人胸部CT为5.0±3.2%(0-17.2%)。中心层面SSDE法的准确性与患者体型相关(BMI:r = 0.15-0.43;体重r = 0.26-0.49),这导致小体型患者的SSDE被高估,大体型患者的SSDE被低估。使用中心层面计算SSDE会导致2%-5%的误差;然而,大体型患者的SSDE被低估,小体型患者的SSDE被高估。