Visual Search in Abdominopelvic CT Interpretation: Accuracy and Time Efficiency Between Coronal MPR and Axial Images

Rationale and Objectives: The objective of this study was to compare reader accuracy and time efficiency between coronal reformats of abdominopelvic computed tomography (CT) and axial images, by means of a visual search task. Materials and methods: In this experimental crossover study, a novel visual search task, containing targets placed on actual CT images, was constructed to assess reader performance on both planes. Six trials were shown to participants in each plane, at a fixed time of 0.5 seconds per slice. The task was presented to 43 junior doctors. On each trial, participants were assessed for accuracy and confidence in finding the target on a five-point scale. Statistical analysis was performed using the Wilcoxon signed rank test, and Fleiss kappa. Results: Coronal images took 40% less time to view overall. No significant difference was found in reader accuracy or reader confidence between the two planes. Interrater agreement was observed as fair, across a very large number of raters (43). Conclusions: Target identification in the coronal plane is extremely similar to the axial plane on abdominopelvic CT in this study and offers a substantial time benefit. A perceptual limit to visual processing of CT images may contribute to this similarity. Greater use of corona' reformats in day-to-day practice could substantially improve radiologist workflow.