Magnetic resonance imaging characteristics of deep endometriosis

The aim of this study was to describe magnetic resonance (MR) imaging findi ngs in histopathologically proven deep endometriosis infiltrating the utero sacral ligaments, the pouch of Douglas, the rectum or the bladder. Twenty p atients presenting with a clinical suspicion of deep endometriosis underwen t preoperative MR imaging. Sagittal and axial fast T2- and axial T1-weighte d spin echo MR sequences were performed. Four patients had post-contrast im ages. MR results, including morphology and signal intensity of each lesion, mere compared to intraoperative gross appearance and histopathology. Histo pathology diagnosed 24 lesions of deep endometriosis in the uterosacral lig aments (n = 12), the pouch of Douglas (n = 2), the rectum (n = 3), the blad der (n = 7), Uterosacral ligaments with deep endometriosis were statistical ly different from normal uterosacral ligaments for proximal nodularity (P = 0.001), There was no difference in signal intensity between normal and abn ormal uterosacral ligaments. Contrast-enhanced SE images in four patients w ith detrusor invasion showed an interruption of the hypointense detrusor by the enhancing bladder endometriosis, Rectal endometriosis was missed in tw o of three patients and showed nan-specific rectal wall thickening in one p atient. It is concluded that MR imaging can diagnose deep endometriosis of uterosacral ligaments, the bladder and the pouch of Douglas, but lacks sens itivity in detecting rectal endometriosis without rectal distension.