感蓝、感绿屏片在腰椎和腹部上影像质量及入射剂量的探讨

目的 探讨感蓝、感绿不同的屏片体系，在腰椎和腹部平片上形成影像质量及入射剂量的差异。材料与方法 （1）测量两种不同屏片的感光性能。（2）热释光剂量仪测试皮肤入射剂量。（3）分别对80例在不同屏片上的腰椎及腹部平片影像密度和对比度进行测试，同时由高年资医师和技师以主观方式比较、评价影像质量。结果 蓝系或绿系在较佳的感光条件下，影像质量均能达到甲级片并接近客观密度标准，但是甲级率绿系高于蓝系约10％，而绿系的皮肤入射剂量是蓝系的1／4－1／5。结论 影像质量不仅仅以主观评价或影像密度为依据，还应以最小剂量获得最佳影像才是一张真正的优质片。

Radiographic Imaging Quality and Exposure Dose of Lumbar Vertebrae and Abdomen Using Blue or Green Screen

Objective　To investigate the difference in imaging quality and X-ray dose for plain film of lumbar vertebrae and abdomen when using blue screen or green screen.　Materials and Methods　(1) The sensitivity of the two kinds of screen was tested. (2) The radiographic dose on skin was measured with TSD. (3) The image density and contrast of the plain film, X-rayed with blue and green screen separately, of lumbar vertebrae and abdomen in 80 cases were measured, the evaluation of the film quality was also made by experienced physicians and technicians.　Results　Both “A” grade imaging quality and objective density criterion were obtained in all cases using either blue or green screen. The exposure dose of the skin with green screen was 20%～25% of that with blue screen. 　Conclusion　An optimal radiography is to get a film of best imaging quality with minimum X-ray exposure dose.