University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland.
Department for Oral Surgery, Oral Radiology and Oral Medicine, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Nov;126(5):439-443. doi: 10.1016/j.oooo.2018.08.003. Epub 2018 Aug 18.
This study aimed to evaluate the effect of different ambient light levels on observer detection of small contrast differences in a contrast phantom by using a high-end liquid crystal display (LCD) monitor.
An aluminum step wedge was converted into a contrast phantom by the addition of bore holes. Radiographic images of the contrast elements were presented to 20 observers. Images were displayed in random order under different ambient light levels (0, 50, 200, and 500 lux) twice, and the observers had to determine if contrast elements were visible. Sensitivity and specificity were determined to calculate areas under receiver operating characteristic curves and Friedmann's test was applied to evaluate the influence of the ambient light level on observer performance.
Mean AZ values were moderate for each ambient light level at 0.715, 0.793, 0.764, and 0.722 for 0, 50, 200, and 500 lux, respectively. The influence of the ambient light level on observer performance was not statistically significant (P > .05).
There was no significant influence of ambient light between 0 and 500 lux on observer ability to detect small contrast details displayed on a high-end LCD monitor.
本研究旨在评估不同环境光水平对观察者在使用高端液晶显示器（LCD）监视器时检测对比度幻象中小对比度差异的影响。
通过添加孔将铝阶跃楔形物转换为对比度幻象。将对比度元素的射线照相图像呈现给 20 名观察者。在不同的环境光水平（0、50、200 和 500 勒克斯）下两次随机显示图像，并要求观察者确定对比度元素是否可见。确定灵敏度和特异性以计算接收器操作特性曲线下的面积，并应用弗里德曼检验评估环境光水平对观察者性能的影响。
对于每个环境光水平，0、50、200 和 500 勒克斯时的平均 AZ 值分别为 0.715、0.793、0.764 和 0.722，均为中等。环境光水平对观察者性能的影响没有统计学意义（P >.05）。
在 0 到 500 勒克斯之间的环境光对观察者检测高端 LCD 监视器上显示的小对比度细节的能力没有显著影响。
