Alex Detrich¹ (), Katrina Visintainer², K. Hudson Guttman¹, Dongyu Zhang², Jason Orlosky², Megan Mills¹, Jeanine Stefanucci¹; ¹University of Utah, ²Augusta University

Radiologic interpretation error rates are estimated to occur in 3-5% of cases and can lead to costly misdiagnoses. In radiology practice, complex three-dimensional (3D) anatomy is typically viewed in two-dimensions (2D). Because translating 2D images into 3D requires increased mental effort and draws on limited cognitive resources, it can contribute to errors in perception and interpretation. To assess whether immersive virtual reality (VR) can reduce mental load, this study compared novices’ performance across three methods that portrayed anatomy in 2D and 3D for detecting acetabular pelvic fractures. Participants (n=55) completed 15 trials (five per condition) in VR. They annotated fractures of the pelvis from computed tomography (CT) and rated confidence after each trial. Three visualization conditions were tested: 2D volumetric (CT scans on the wall), 3D (static rendered pelvis), and combined 2D volumetric + 3D. Most participants had prior VR experience (71.4%) and little CT experience (94.6%). Repeated-measures ANOVAs examined confidence, reaction time, and accuracy across conditions. Trial-by-trial confidence did not differ, F(1.79,96.73) = 1.62, p = .205, η²G = 0.01. Response times differed significantly, F(2,108) = 20.90, p < .001, η²G = 0.10. Bonferroni-corrected pairwise comparisons showed no difference between 2D volumetric and 2D volumetric + 3D, t(54) = 0.78, p = 0.438, but 3D was faster than both 2D volumetric, t(54) = 5.79, p < .001, and 2D volumetric + 3D, t(54) = 5.38 p < .001 (3D: M = 90.0, SD = 45.5; volumetric: M = 132.0, SD = 67.8; volumetric + 3D: M = 126.0, SD = 54.9). Accuracy did not differ among conditions, F(2,108) = 1,77, p = .176, η²G = 0.01. Overall, 3D viewing enabled faster detection of pelvic fractures compared to 2D or combined 2D+3D viewing conditions in novices. Future work will extend this research to participants with CT viewing experience.