McCrohan J L, Patterson J F, Gagne R M, Goldstein H A
Radiology. 1987 Apr;163(1):263-8. doi: 10.1148/radiology.163.1.3823446.
Approximately 250 computed tomography (CT) systems were surveyed in a nationwide study to determine the average radiation dose resulting from a typical adult head procedure. The multiple scan average dose (MSAD) was selected as the dose descriptor. For the typical adult CT head procedure, the MSAD was generally within 2.2-6.8 rads (22-68 mGy). Variations in dose by a factor of two or more were often seen for a given manufacturer and model. These dose ranges indicate a potential to reduce dose by carefully selecting imaging techniques. Overall, variations in dose can result from differences in the user's choice of technique (desired image quality) or from actual differences in scanner performance (caused by differences in collimation, filtration, or geometry). To use CT appropriately, a facility should consider dose as well as image quality in selecting optimal techniques for typical modes of operation.
在一项全国性研究中，对约250台计算机断层扫描（CT）系统进行了调查，以确定典型成人头部检查产生的平均辐射剂量。选择多次扫描平均剂量（MSAD）作为剂量描述指标。对于典型的成人CT头部检查，MSAD一般在2.2 - 6.8拉德（22 - 68毫戈瑞）范围内。对于给定的制造商和型号，剂量变化往往达到两倍或更多。这些剂量范围表明，通过仔细选择成像技术有可能降低剂量。总体而言，剂量变化可能源于用户对技术的选择（期望的图像质量）差异，或源于扫描仪性能的实际差异（由准直、过滤或几何结构差异导致）。为了合理使用CT，医疗机构在为典型操作模式选择最佳技术时，应同时考虑剂量和图像质量。
