Huda Walter, Nickoloff Edward L, Boone John M
Department of Radiology, Medical University of South Carolina, Charleston, South Carolina 29425-3230, USA.
Med Phys. 2008 Dec;35(12):5713-28. doi: 10.1118/1.3013604.
This review covers the role of medical physics in addressing issues directly related to patient dosimetry in radiography, fluoroscopy, mammography, and CT. The sections on radiography and fluoroscopy radiation doses review the changes that have occurred during the last 50 to 60 years. A number of technological improvements have contributed to both a significant reduction in patient and staff radiation doses and improvements to the image quality during this period of time. There has been a transition from film-screen radiography with hand dip film processing to electronic digital imaging utilizing CR and DR. Similarly, fluoroscopy has progressed by directly viewing image intensifiers in darkened rooms to modern flat panel image receptor systems utilizing pulsed radiation, automated variable filtration, and digitally processed images. Mammography is one of the most highly optimized imaging procedures performed, because it is a repetitive screening procedure that results in annual radiation exposure. Mammography is also the only imaging procedure in the United States in which the radiation dose is regulated by the federal government. Consequently, many medical physicists have studied the dosimetry associated with screen-film and digital mammography. In this review, a brief history of mammography dose assessment by medical physicists is discussed. CT was introduced into clinical practice in the early 1970s, and has grown into one of the most important modalities available for diagnostic imaging. CT dose quantities and measurement techniques are described, and values of radiation dose for different types of scanner are presented. Organ and effective doses to adult patients are surveyed from the earliest single slice scanners, to the latest versions that include up to two x-ray tubes and can incorporate as many as 256 detector channels. An overview is provided of doses received by pediatric patients undergoing CT examinations, as well as methods, and results, of studies performed to assess the radiation absorbed by the conceptus of pregnant patients.
本综述涵盖医学物理在解决与X线摄影、透视、乳腺摄影和CT中患者剂量测定直接相关问题方面的作用。关于X线摄影和透视辐射剂量的章节回顾了过去50至60年中发生的变化。在此期间，多项技术改进促成了患者和工作人员辐射剂量的显著降低以及图像质量的提高。从采用手工冲洗胶片的屏片摄影过渡到了利用CR和DR的电子数字成像。同样，透视也从在暗室中直接观察影像增强器发展到了采用脉冲辐射、自动可变滤过和数字处理图像的现代平板影像接收器系统。乳腺摄影是执行得最为优化的成像检查之一，因为它是一种重复性筛查检查，会导致年度辐射暴露。乳腺摄影也是美国唯一一项辐射剂量由联邦政府监管的成像检查。因此，许多医学物理学家研究了与屏片乳腺摄影和数字乳腺摄影相关的剂量测定。在本综述中，讨论了医学物理学家对乳腺摄影剂量评估的简要历史。CT于20世纪70年代初引入临床实践，现已发展成为最重要的诊断成像方式之一。描述了CT剂量量和测量技术，并给出了不同类型扫描仪的辐射剂量值。调查了从最早的单层扫描仪到最新版本（包括多达两个X射线管且可包含多达256个探测器通道）的成年患者的器官剂量和有效剂量。概述了接受CT检查的儿科患者所接受的剂量，以及为评估孕妇胎儿所吸收辐射而进行的研究的方法和结果。
