MRI directed US for rectosigmoid endometriosis provides added value for preoperative planning.

Endometriosis is a multifocal disease of pelvis affecting mostly reproductive age women. It can involve genital and extra genital organs. The gastrointestinal tract including rectum and sigmoid colon is the most affected extragenital site. Bowel involvement can change the surgery from simple shaving to resection based on depth of invasion and disease distribution. Benefit of ultrasound for bowel endometriosis, especially for rectum and rectosigmoid colon have been reported, however MRI directed ultrasound, particularly for the lesions which demonstrate indeterminate depth of wall invasion and multifocal bowel involvement hasn't been reported. Here we present a case of rectosigmoid endometriosis evaluated with preoperative MRI directed ultrasound, which provided better visualization of muscularis propria invasion of the bowel and multifocal lesions.