Magnet Resonance Imaging in Preoperative Endometriosis: Incidence of High-Signal-Intensity Spots on Fat-Suppressed T1-Weighted and T2-Weighted Images

Abstract

Objectives: To investigate the incidence of high-signal-intensity lesions at preoperative T1 and T2-weighted magnet resonance imaging (MRI) in patients with pelvic endometriosis.Study Design: Between 2009 and 2012, 252 women with clinical and sonographic suspicion of endometriosis underwent pelvic MRI using T2 and unenhanced T1 sequences with and without fat saturation. Two radiologists interpreted the following regions retrospectively by consensus according to a standardized protocol: uterus, vagina, pouch of Douglas, rectum, uterosacral ligament (USL). High-signal-intensity lesions in the fat-suppressed T1-weighted images were defined as hemorrhagic foci. Their incidence and that of high-signal-intensity spots in T2-weighted images were documented in histopathological verified endometriosis. Results:In patients with rectal endometriosis (128/252 patients), high-signalintensity spots were detected on 10.2% of T1-weighted fat-suppressed images and on 16.9% of T2-weighted images. In uterus adenomyosis (236/252 patients) high-signal-intensity spots on T1 and T2 weighted images occurred in 43.2% and 24.2%, respectively (vagina (115/252, 31.3% and 41.9%; USL 119/252, 7.6% and 13.8%, pouch of Douglas 169/252, 31.4% and 28.1%, other localizations 7/252, 71.4% and 57.1%) Conclusion:The incidence of high-signal-intensity spots on T1 and T2-weighted images depends on the localization of endometriosis. T1 und T2 high-signalintensity spots are less relevant in diagnosing endometriosis of the rectum and uterosacral ligament.