Mileto Achille, Nelson Rendon C, Larson Douglas G, Samei Ehsan, Wilson Joshua M, Christianson Olav, Marin Daniele, Boll Daniel T
1 Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific St, Seattle, WA 98195.
2 Department of Radiology, Duke University Medical Center, Durham, NC.
AJR Am J Roentgenol. 2017 Jun;208(6):1285-1296. doi: 10.2214/AJR.16.17070. Epub 2017 Mar 28.
The purpose of this study was to conduct longitudinal analyses of radiation dose data from adult patients undergoing clinically indicated, repeat identical thoracoabdominal CT examinations.
Radiation dose data were electronically collected from 2851 subjects undergoing 12,635 repeat identical CT scans (mean number of scans per patient, 4.8; range, 2-33) in one health system. Included CT protocols were chest-abdomen-pelvis with contrast administration (n = 4621 CT studies of 1064 patients), abdomen-pelvis with contrast administration (n = 876 CT studies of 261 patients), renal stone (n = 1053 CT studies of 380 patients), and chest (n = 6085 CT studies of 1146 patients) without contrast administration. A radiation-tracking software infrastructure was adopted to extract data from DICOM headers in PACS. Size-specific dose estimate (SSDE) was calculated.
A trend was observed toward global reduction in SSDE values with all protocols investigated (chest-abdomen-pelvis slope, -1.78; abdomen-pelvis slope, -0.82; renal stone slope, -0.83; chest slope, -0.47; p < 0.001 for all comparisons). The intraindividual analyses of radiation dose distribution showed widespread variability in SSDE values across the four protocols investigated (chest-abdomen-pelvis mean coefficient of variance, 14.02 mGy; abdomen-pelvis mean coefficient of variance, 10.26 mGy; renal stone mean coefficient of variance, 34.18 mGy; chest mean coefficient of variance, 6.74 mGy).
Although there is a trend toward global reduction in radiation doses, this study showed widespread variability in the radiation dose that each patient undergoing identical repeat thoracoabdominal CT protocols absorbs. These data may provide a foundation for the future development of best-practice guidelines for patient-specific radiation dose monitoring.
本研究旨在对接受临床指征的重复相同胸腹CT检查的成年患者的辐射剂量数据进行纵向分析。
从一个医疗系统中2851名接受12635次重复相同CT扫描的受试者（每位患者的平均扫描次数为4.8次；范围为2 - 33次）中电子收集辐射剂量数据。纳入的CT检查方案包括胸部 - 腹部 - 骨盆增强扫描（1064例患者的4621次CT检查）、腹部 - 骨盆增强扫描（261例患者的876次CT检查）、肾结石扫描（380例患者的1053次CT检查）以及胸部平扫（1146例患者的6085次CT检查）。采用辐射跟踪软件基础设施从PACS中的DICOM头文件中提取数据。计算了大小特异性剂量估计值（SSDE）。
在所研究的所有检查方案中均观察到SSDE值总体呈下降趋势（胸部 - 腹部 - 骨盆斜率为 - 1.78；腹部 - 骨盆斜率为 - 0.82；肾结石斜率为 - 0.83；胸部斜率为 - 0.47；所有比较的p < 0.001）。辐射剂量分布的个体内分析显示，在所研究的四种检查方案中，SSDE值存在广泛的变异性（胸部 - 腹部 - 骨盆平均变异系数为14.02 mGy；腹部 - 骨盆平均变异系数为10.26 mGy；肾结石平均变异系数为34.18 mGy；胸部平均变异系数为6.74 mGy）。
尽管辐射剂量总体呈下降趋势，但本研究表明，接受相同重复胸腹CT检查方案的每位患者所吸收的辐射剂量存在广泛的变异性。这些数据可为未来制定针对患者的辐射剂量监测最佳实践指南提供基础。
