CR摄影与屏-片摄影的比较

The comparative analysis of computed radiography（CR） and screen-film radiography＇ exposure condition

目的探讨CR摄影与屏-片系统摄影曝光条件及对患者的X射线辐射剂量，评价CR摄影的应用价值。方法取本院CR照片和常规X射线摄影照片各2500份，由2位主管技师和1位副主任技师对照片按部位分组进行分析，统计出甲、乙、丙及废片率；并对乙、丙及废片产生的原因进行分析。结果①照片质量：CR摄影照片甲级片率63．6％，乙级片率27．2％，丙级片率9．2％，废片率0％；屏-片系统摄影照片甲级片率40．2％，乙级片率42．4％，丙级片率15．6％，废片率1．8％。②摄影条件的比较：CR数字摄影比屏．片系统摄影电压需提高1-6kV，曝光量高20％左右。结论CR数字摄影照片质量明显高于屏-片系统摄影，但曝光条件比屏-片系统高，相对增加了患者的X射线辐射剂量。

Objective To explore the exposure condition of CR and screen-film radiography and the radiation dose to patients, and to evaluate image quality of the CR system. Methods Two thousand and five hundred sheets of CR and screen-film radiography images were selected and then analyzed by two junior radiologists and one senior radiologist. Results （1）The quality of the images was classified into grades A, B, C： grade A in 63.6% , grade B in 27.2% , grade C in 9.2% ,waste in 0% for CR while grade A in 40.2% , grade B in 42.4%, grade C in 15.6% ,waste in 1.8% for screen-film radiography. （2）The required voltage of CR system was 1-6 kV higher and radiantion exposure was increased by about 20% than the screen-film radiography system. Conclusions The imaging quality of CR was obviously higher than that of the screen-film radiography, providing reliable diagnosis evidence for clinical practice, but the disadvantage of CR system was the higher exposure condition required, which increase the patient dose.