Endometrial Carcinoma: Evaluation of Depth of Myometrial Invasion by MR Imaging - Preliminary Report

The depth of myometrial invasion is closely related to the incidence of lymph node metastasis and prognosis in patients with endometrial carcinoma. The purpose of this study is to assess the role of MR imaging in endometrial cancer, with emphasis on the evaluation of depth of myometrial invasion. Twenty-two women with clinical International Federation of Gynecology and Obstetrics (FIGO) stage I endometrial carcinoma diagnosed by fractional dilatation and curettage (D&C) were referrred for preoperative MR study. MR imaging was performed with fast spin echo (FSE) T2-weighted image (T2WI) and post-enhanced spin echo T1-weighted image (T1WI). Results of MR findings were correlated with histopathologic examination of surgical specimens after abdominal hysterectomy. Accuracy of MR staging of IA, IB and IC disease by T2WI alone and combined readings of T2WI with post-enhanced T1WI were 64% (14/22) and 68% (15/22), respectively. Bulky endometrial tumors, irregular and/or indistinct junctional zones, poor tumor-myometrial contrast and minimal (microscopic) myometrial invasion were the most causes of incorrect MR staging. The accuracy rates for T2WI and the combined reading for differentiating superficial (stage IA + IB) from deep invasive (stage IC) disease were both 85%. Based on this preliminary study, MR imaging is reliable in differentiating superficial from deep invasive disease in endometrial carcinoma.