MRI interobserver reliability in rectal tumor angulation.

Abstract

BackgroundWhen rectal tumors are examined using magnetic resonance imaging (MRI) the perpendicular angulation of the axial T2-weighted image to the tumor axis is essential for a correct measure of the shortest distance between tumor and mesorectal facia.PurposeThe purpose of this study was to determine the interobserver variability in rectal tumor angulation between a radiologist and a radiographer.Material and MethodsTwo observers performed the angulation independently. All MRI examinations were performed using an MRI 1.5 Tesla unit. A Bland–Altman plot was used to assess the interobserver variance and Intraclass correlation coefficient (ICC) statistic was used to assess the interobserver reliability.ResultsMRI was performed in 55 patients with rectal cancer during a one-year period (25 (45.5%) women and 30 (54.5%) men). The median age was 71 years (range 46–87 years). The rectal tumor mean length was 3.9 cm. The interobserver reliability was good (ICC = 0.83, 95% confidence interval 0.72–0.90).ConclusionRadiographers receiving training will be able to perform MRI rectal tumor angulation.