ENHANCED DISPLAYS OF MEDICAL IMAGES - EVALUATION OF THE EFFECTIVENESSOF COLOR, MOTION, AND CONTOUR FOR DETECTING AND LOCALIZING LIVER-LESIONS

Rationale and Objectives. Many perceptual studies have shown that the detection of large, low-contrast targets is better either in color or in contrast-reversing presentations than in standard gray scale. We de termined the value of several new display techniques for viewing liver computed tomography (CT) scans.Methods. Eight observers (four radiolo gists and four nonradiologists) viewed sets of 100 liver CT images (50 with lesions and 50 without) under five display conditions on a Macin tosh computer: (1) color (equiluminant color contrast); (2) color-lumi nance (combined luminance and chromatic contrast), (3) flicker (lumina nce contrast that reversed polarity at 2 Hz); (4) contour (shaded inte nsity mapping); and (5) control (conventional gray scale). Receiver op erating characteristic (ROC) techniques were used for analysis. Result s. The measured ROC curve areas for the different viewing conditions w ere as follows: control = 0.77 +/- 0.01 (mean +/- standard error of th e mean); color = 0.78 +/- 0.01; color-luminance = 0.82 +/- 0.01; flick er = 0.78 +/- 0.01; and contour = 0.76 +/- 0.01. The percentage of les ions correctly located ranged from 0.82 (color-luminance) to 0.75 (fli cker). Performance under the color-luminance condition was significant ly better than in the control condition (p = .01), whereas the other e xperimental conditions were not significantly different from the contr ol condition (p > .21). Conclusion. The use of mixed color and luminan ce displays may have perceptual advantages for radiologists and can im prove performance over that of gray-scale viewing.