Kaczmarek R V, Conway B J, Slayton R O, Suleiman O H
U.S. Food and Drug Administration, Center for Devices and Radiological Health, Rockville, MD 20850, USA.
Radiology. 2000 Jun;215(3):891-6. doi: 10.1148/radiology.215.3.r00jn43891.
To provide public health information by means of measurement of the radiation exposures that patients undergoing chest radiography would receive and to compare the results with those of a similar previous survey.
Surveyed facilities were randomly selected from each state. Patient exposure was evaluated along with film processing, half-value layer, and image quality. Additional information obtained concerned type of equipment, facility work load, radiographic technique, screen-film system, and grid type.
Mean entrance air kerma in all facilities was 141 microGy (16.1 mR). Mean kilovoltage in all facilities was 101 kV. In 1994, 140 (90%) of 156 hospitals (vs 71% in 1984) and 92 (58%; nearly double the percentage in 1984) of 159 nonhospital sites were using grids. Scoring with the imaging test tool resulted in a mean spatial resolution of 2.3 cycles per millimeter, and a mean low-contrast sensitivity of about 3%. Two hundred fifty-three (80%) of 315 facilities surveyed were processing film at minimum acceptable performance levels.
Mean entrance air kerma for all facilities did not substantially change. Although increased grid usage would lead to the expectation of higher measured exposures, this was offset by an increase in the use of faster screen-film combinations.
通过测量接受胸部X线摄影的患者所接受的辐射剂量来提供公共卫生信息，并将结果与之前类似调查的结果进行比较。
从每个州随机选择被调查的机构。对患者的辐射剂量以及胶片处理、半值层和图像质量进行评估。获取的其他信息包括设备类型、机构工作量、射线照相技术、增感屏-胶片系统和滤线栅类型。
所有机构的平均入射空气比释动能为141微戈瑞（16.1毫伦琴）。所有机构的平均千伏数为101 kV。1994年，156家医院中的140家（90%，而1984年为71%）以及159个非医院场所中的92家（58%；几乎是1984年百分比的两倍）使用了滤线栅。使用成像测试工具评分得出的平均空间分辨率为每毫米2.3周期，平均低对比度敏感度约为3%。在接受调查的315家机构中，有253家（80%）的胶片处理达到了最低可接受性能水平。
所有机构的平均入射空气比释动能没有显著变化。尽管滤线栅使用的增加会导致预期测量的辐射剂量更高，但这被更快的增感屏-胶片组合使用的增加所抵消。
