Evaluation of a flat CRT monitor for use in radiology

Medical radiographs based on familiar projection techniques are planar images traditionally displayed by placing on a flat surface viewbox. Presenting these planar images in digital form on a traditional monitor with a curved surface may cause distortions, possibly affecting diagnoses. This would be true especially if physical linear dimensions of the anatomy are important. Reflections from ambient lights behind the observer also could be a problem with curved displays. The goal of this study was to compare physical and psychophysical performance of a flat-surface display monitor with a traditional curved-surface monitor. Two display monitors with different types of front glass-panel surfaces were evaluated. The first monitor had a traditional curved surface, and the other had a flat surface. Physical measurements included dynamic range, display function, veiling glare, and spatial uniformity. An observer performance study used low-contrast, square-wave patterns to determine just-noticeable differences. Ambient lights were turned off in one condition and on in the other. Physical measurements showed that the display functions were nearly identical, but uniformity, veiling glare, and signal-to-noise-ratio were better for the curved monitor. Observer performance was better overall with the curved monitor, but the degradation in performance between lights off and lights on was greater for the curved than flat monitor. The greater degradation with the lights on could be attributed to more reflections off the curved than the flat monitor. A flat-surface display monitor may be useful for viewing clinical radiographs.