Ambient lighting: effect of illumination on soft-copy viewing of radiographs of the wrist.
OBJECTIVE
The aim of the work was to establish optimum ambient light conditions for viewing radiologic images of the wrist on liquid crystal display monitors.


METHODS
Five ambient light levels were investigated: 480, 100, 40, 25, and 7 lux. Seventy-nine experienced radiologists were asked to examine 30 posteroanterior wrist images and decide whether a fracture was present. All images were displayed on liquid crystal display monitors. Receiver operating characteristic analysis was performed, and the numbers of false-positive and false-negative findings were recorded.


RESULTS
For all the radiologists, greater area under the receiver operating characteristic curve and lower numbers of false-positive and false-negative findings were recorded at 40 and 25 lux compared with 480 and 100 lux. At 7 lux, the results were generally similar to those at 480 and 100 lux. The experience and knowledge of radiologists specializing in imaging of musculoskeletal trauma appeared to compensate in part for inappropriate lighting levels.


CONCLUSIONS
Typical office lighting and current recommendations on ambient lighting can reduce diagnostic efficacy compared with lower levels of ambient lighting. If, however, no light other than that of the monitor is used, results are similar to those with excessive levels of lighting. Careful control of ambient lighting is therefore required to ensure that diagnostic accuracy is maximized, particularly for clinicians not expert in interpreting posteroanterior wrist images.
Brennan
Patrick C
PC
School of Medicine and Medical Sciences, University College Dublin, Health Science Bldg., Belfield, Dublin 4, Ireland.
McEntee
Mark
M
Evanoff
Michael
M
Phillips
Peter
P
O'Connor
William T
WT
Manning
David J
DJ
D016288:Computer Terminals; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D008029:Lighting / Q000379:methods*; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis; D014796:Visual Perception; D014954:Wrist Injuries / Q000000981:diagnostic imaging*; D014963:X-Ray Intensifying Screens