<title>Influence of monitor luminance and tone scale on observers' search and dwell patterns</title>

Abstract

The goal of this study was to measure the influence of monitor display luminance and tone scale on diagnostic performance and visual search behavior. Radiologists viewed 50 pairs of mammograms in two experiments. The first experiment changed the monitor's tone scale from its default (non-linearized) scale to the DICOM Barten scale (perceptually linearized). The second study compared an 80 ftL with a 140 ftL monitor. Eye- position was recorded. Performance with the Barten was higher than with the default curve. Performance with the 140 ftL was higher than with the 80 ftL monitor. Viewing time did not differ for tone scale, but was significantly shorter for 140 ftL vs 80 ftL. The number of fixation clusters generated was higher for the 80 ftL and the default tone scale. The difference was significant for lesion-free images. Median decision dwell times were longer in the default and 80 ftL conditions. Display luminance and tone scale affect diagnostic and search performance when using monitors. Lower luminance levels and a non-linearized display prolong search and recognition of normal, lesion-free areas compared to lesion- containing areas -- radiologists are having more trouble deciding that areas are truly normal. It is recommended that such factors as monitor luminance and choice of tone scale be taken into account when deciding to use CRT monitors for viewing radiographic images in the clinical environment.