From the Departments of Diagnostic Radiology (A.L., M.G., J.W., G.G.) and Emergency Medicine (C.L.M.), Yale University School of Medicine, 464 Congress Ave, Suite 260, New Haven, CT 06519; and American College of Radiology, Reston, Va (M.B., L.C.).
Radiology. 2014 May;271(2):445-51. doi: 10.1148/radiol.14131601. Epub 2014 Jan 27.
To determine radiation dose indexes for computed tomography (CT) performed with renal colic protocols in the United States, including frequency of reduced-dose technique usage and any institutional-level factors associated with high or low dose indexes.
The Dose Imaging Registry (DIR) collects deidentified CT data, including examination type and dose indexes, for CT performed at participating institutions; thus, the DIR portion of the study was exempt from institutional review board approval and was HIPAA compliant. CT dose indexes were examined at the institutional level for CT performed with a renal colic protocol at institutions that contributed at least 10 studies to the registry as of January 2013. Additionally, patients undergoing CT for renal colic at a single institution (with institutional review board approval and informed consent from prospective subjects and waiver of consent from retrospective subjects) were studied to examine individual renal colic CT dose index patterns and explore relationships between patient habitus, demographics, and dose indexes. Descriptive statistics were used to analyze dose indexes, and linear regression and Spearman correlations were used to examine relationships between dose indexes and institutional factors.
There were 49 903 renal colic protocol CT examinations conducted at 93 institutions between May 2011 and January 2013. Mean age ± standard deviation was 49 years ± 18, and 53.9% of patients were female. Institutions contributed a median of 268 (interquartile range, 77-699) CT studies. Overall mean institutional dose-length product (DLP) was 746 mGy ⋅ cm (effective dose, 11.2 mSv), with a range of 307-1497 mGy ⋅ cm (effective dose, 4.6-22.5 mSv) for mean DLPs. Only 2% of studies were conducted with a DLP of 200 mGy ⋅ cm or lower (a "reduced dose") (effective dose, 3 mSv), and only 10% of institutions kept DLP at 400 mGy ⋅ cm (effective dose, 6 mSv) or less in at least 50% of patients.
Reduced-dose renal protocol CT is used infrequently in the United States. Mean dose index is higher than reported previously, and institutional variation is substantial.
确定美国采用肾绞痛方案进行的计算机断层扫描（CT）的辐射剂量指标，包括降低剂量技术的使用频率以及与高剂量或低剂量指标相关的任何机构水平因素。
剂量成像登记处（DIR）收集来自参与机构的 CT 数据，包括检查类型和剂量指标，因此该研究的 DIR 部分免于机构审查委员会的批准并符合 HIPAA 规定。2013 年 1 月前，至少有 10 项研究为该注册中心做出贡献的机构，对采用肾绞痛方案进行 CT 的机构进行了 CT 剂量指标的机构水平检查。此外，对一家机构进行的肾绞痛 CT 检查（经机构审查委员会批准，前瞻性受试者知情同意，回顾性受试者同意豁免）进行了研究，以检查个体肾绞痛 CT 剂量指数模式，并探讨患者体型、人口统计学和剂量指标之间的关系。采用描述性统计分析剂量指标，采用线性回归和斯皮尔曼相关性分析来检验剂量指标与机构因素之间的关系。
2011 年 5 月至 2013 年 1 月期间，93 家机构共进行了 49903 次肾绞痛方案 CT 检查。平均年龄±标准差为 49 岁±18 岁，53.9%的患者为女性。各机构平均贡献 268 项（四分位距，77-699）CT 研究。总体平均机构剂量长度乘积（DLP）为 746mGy ⋅ cm（有效剂量为 11.2mSv），DLP 范围为 307-1497mGy ⋅ cm（有效剂量为 4.6-22.5mSv）。只有 2%的研究采用 200mGy ⋅ cm 或更低的 DLP 进行（“降低剂量”）（有效剂量为 3mSv），只有 10%的机构在至少 50%的患者中将 DLP 保持在 400mGy ⋅ cm（有效剂量为 6mSv）或更低。
在美国，降低剂量的肾绞痛方案 CT 很少使用。平均剂量指标高于先前报告的水平，且机构间差异很大。
