Pelvic MRI for Endometriosis: A Diagnostic Challenge for the Inexperienced Radiologist. How Much Experience Is Enough?

PURPOSE: The purpose of this study was to investigate the impact of radiologist experience on diagnostic performance of pelvic magnetic resonance imaging (MRI) for the evaluation of endometriomas and different localisations of deep pelvic endometriosis (DPE). MATERIALS AND METHODS: In this prospective study all pelvic MRI examinations performed for pelvic endometriosis from December 2016 to August 2017 were evaluated by readers with different experience levels; junior resident (0-6 weeks of experience in female imaging), senior resident (7-24 weeks), fellow (6-24 months), and expert (10 years) in female imaging for the presence of endometriomas and DPE. Their evaluations were compared with surgery confirmed with pathology. Diagnostic performances of readers with different levels of experience were studied by the means of receiving operating characteristic curves and areas under the curve (AUC) were compared with the ones of the expert reader. RESULTS: Of 174 patients evaluated, the standard of reference was available for 59, consisting the final population of the study. The AUC for endometriomas, DPE for the posterior and anterior pelvic compartment, for rectosigmoid DPE and for overall evaluation were 0.983, 0.921, 0.615, 0.862, and 0.914 for the expert reader, 0.966 (p = 0.178), 0.805 (p = 0.001), 0.605 (p = 0.91), 0.872 (p = 0.317), and 0.849 (p = 0.0009) for the fellow level, 0.877 (p = 0.002), 0.757 (p < 0.001), 0.585 (p = 0.761), 0.744 (p = 0.239), and 0.787 (p = < 0.001) for the senior resident level and 0.861 (p = 0.177), 0.649 (p < 0.001), 0.648 (p = 0.774), 0.862 (p = 1), and 0.721 (p < 0.001) for the junior resident level. CONCLUSIONS: According to our results, interpretation of pelvic MRI for DPE should be performed by specialists as; even the performance of radiologists with up to 2 years of experience in female imaging was statistically inferior to that of experts.