Eye Movements of Radiologists Reflect Expertise in CT Study Interpretation: A Potential Tool to Measure Resident Development

Abstract

Purpose To establish potential markers of visual expertise in eye movement (EM) patterns of early residents, advanced residents, and specialists who interpret abdominal computed tomography (CT) studies. Materials and Methods The institutional review board approved use of anonymized CT studies as research materials and to obtain anonymized eye-tracking data from volunteers. Participants gave written informed consent. Early residents (n = 15), advanced residents (n = 14), and specialists (n = 12) viewed 26 abdominal CT studies as a sequence of images at either 3 or 5 frames per second while EMs were recorded. Data were analyzed by using linear mixed-effects models. Results Early residents' detection rate decreased with working hours (odds ratio, 0.81; 95% confidence interval [CI]: 0.73, 0.91; P = .001). They detected less of the low visual contrast (but not of the high visual contrast) lesions (45% [13 of 29]) than did specialists (62% [18 of 29]) (odds ratio, 0.39; 95% CI: 0.25, 0.61; P < .001) or advanced residents (56% [16 of 29]) (odds ratio, 0.55; 95% CI: 0.33, 0.93; P = .024). Specialists and advanced residents had longer fixation durations at 5 than at 3 frames per second (specialists: β = .01; 95% CI: .004, .026; P = .008; advanced residents: β = .04; 95% CI: .03, .05; P < .001). In the presence of lesions, saccade lengths of specialists shortened more than those of advanced (β = .02; 95% CI: .007, .04; P = .003) and of early residents (β = .02; 95% CI: .008, 0.04; P = .003). Irrespective of expertise, high detection rate correlated with greater reduction of saccade length in the presence of lesions (β = -.10; 95% CI: -.16, -.04; P = .002) and greater increase at higher presentation speed (β = .11; 95% CI: .04, .17; P = .001). Conclusion Expertise in CT reading is characterized by greater adaptivity in EM patterns in response to the demands of the task and environment. ^© RSNA, 2016 Online supplemental material is available for this article.