【摘要】 目的　探讨阅片室内环境照度 (IRR)对影像识读的影响。方法　采用观测者操作特性 (ROC)曲线主观评价和观察测试卡分辨率 2种实验方案 :(1)将 6张带有低对比度微小信号的X线胶片置于观片灯上 ;设置阅片室内环境照度分别为 80lx和 5 0 0lx,请 3位放射诊断医师进行影像识读 ,绘制ROC曲线并计算检出的最大信息量Imax。 (2 )将 0 .6～ 10LP/mm的矩形波测试卡紧贴于暗盒上 ,摄胸部正侧位片共 10张 ,使测试卡处于实际影像密度背景中 ;阅片条件同上 ,观察其线对分辨率。结果　 (1)环境照度 80lx条件下的Imax明显高于 5 0 0lx时 ;(2 )阅片室内环境照度 80lx时 ,可辨识的胸片中测试卡线对数高于 5 0 0lx时可辨识的线对数 ,且两者间具有显著性差异 (t≥ 1.92 1、P <0 .0 5 ) ;(3)环境照度对低照度观片灯的影响大、对高照度观片灯的影响小。结论 2　种实验结果均显示 :(1)降低IRR可提高X线胶片分辨率 ,有利于保证诊断质量。 (2 )提高观片灯照度可减小环境照度对影像识读的影响。更多还原

【Abstract】 Objective To study the influence of IRR on imaging reading. Methods (1) To setilluminance in reading room (IRR) to be 80 lx and 500 lx separately, sit films on which there was many small andlow-contrast information were viewed by three doctors on viewboxes. The ROC curves were drawn and the maximuminformation (Imax) was calculated. (2) To put the square-shaped testing-card (0. 6 LP/mm-10LP/mm) oncassette and take 10 pictures of thorax both in horizontal and lateral position. so the testing-card was in thebackground of practical imaging. The LP of the testing-card was observed under the same viewing-conditions asaforesaid. Results (1 ) The Imax when IRR was in 80 lx was obviously higher than in 500lx. (2)The results gotby means of testing-card was the same as above, and there was remarkable difference between in 80lx and in500 lx(t≥1 .921, P < 0.05). (3) The influence of IRR on low-illuminance viewbox was higher than that on highilluminance viewbox. Conclusions (1) Decreasing IRR can improve the resolving power of X-ray films anddiagnostic quality. (2) Increasing the illuminance of viewbox can reduce the influence of IRR on imaging reading.更多还原