Assessments of structure identification and distortion
The Kappa values between the two readers revealed substantial-to-perfect agreement (structure identification provided by SS-EPI: 0.73, distortion by SS-EPI: 1, identification by RS-EPI: 0.75, distortion by RS-EPI: 0.82). The mean scores of structure identification and geometric distortion for SS-EPI and RS-EPI by the two readers are shown inTable 4 . The distortion scores for RS-EPI were significantly higher than those for SS-EPI (all p-values were <0.05), indicating lower distortion, and the image quality provided by RS-EPI was better than that obtained with SS-EPI. However, the results of the median test of the structure identification scores were not significantly different between SS-EPI and RS-EPI.