Structured reporting of pelvic MRI studies can improve sensitivity compared to routine read studies and are preferred by referring physicians [75,76]. MRI pelvis allows imaging with a large field-of-view to include anatomy that is generally beyond the field-of-view for TVUS. Structures that are not well seen by US, such as pelvic nerves, can be depicted by MRI [77,78]. MRI pelvis can be used for surgical planning for bladder endometriosis because it can accurately predict lesion size and Endometriosis involvement of the ureter orifices [46,79]. These studies are also helpful for surgical planning when bowel disease is present as described under Variant 3. MRI Pelvis Without IV Contrast MRI pelvis without IV contrast is helpful for the diagnosis of DE, for further characterization of indeterminate findings on US, and for treatment planning as described in the preceding paragraph. Assessment of ovarian lesions is limited without IV contrast. Variant 3: Adult. Clinically suspected rectosigmoid endometriosis. Initial imaging. The intestinal tract is the most common site of nongynecologic endometriosis. Endometriosis can infiltrate the muscular bowel wall leading to gastrointestinal symptoms. The anterior wall of the rectosigmoid colon is the most common location for bowel endometriosis, followed by the sigmoid colon, cecum and ileocecal valve, appendix. and small bowel [80]. Rectosigmoid bowel lesions can be removed by surgical shaving, discoid resection, or segmental resection. Information from imaging studies is used to predict which of these surgical approaches will be needed. CT Pelvis With IV Contrast There is no relevant literature to support the use of standard pelvic CT without a water enema as an initial imaging modality for clinically suspected rectosigmoid endometriosis.
Endometriosis. Structured reporting of pelvic MRI studies can improve sensitivity compared to routine read studies and are preferred by referring physicians [75,76]. MRI pelvis allows imaging with a large field-of-view to include anatomy that is generally beyond the field-of-view for TVUS. Structures that are not well seen by US, such as pelvic nerves, can be depicted by MRI [77,78]. MRI pelvis can be used for surgical planning for bladder endometriosis because it can accurately predict lesion size and Endometriosis involvement of the ureter orifices [46,79]. These studies are also helpful for surgical planning when bowel disease is present as described under Variant 3. MRI Pelvis Without IV Contrast MRI pelvis without IV contrast is helpful for the diagnosis of DE, for further characterization of indeterminate findings on US, and for treatment planning as described in the preceding paragraph. Assessment of ovarian lesions is limited without IV contrast. Variant 3: Adult. Clinically suspected rectosigmoid endometriosis. Initial imaging. The intestinal tract is the most common site of nongynecologic endometriosis. Endometriosis can infiltrate the muscular bowel wall leading to gastrointestinal symptoms. The anterior wall of the rectosigmoid colon is the most common location for bowel endometriosis, followed by the sigmoid colon, cecum and ileocecal valve, appendix. and small bowel [80]. Rectosigmoid bowel lesions can be removed by surgical shaving, discoid resection, or segmental resection. Information from imaging studies is used to predict which of these surgical approaches will be needed. CT Pelvis With IV Contrast There is no relevant literature to support the use of standard pelvic CT without a water enema as an initial imaging modality for clinically suspected rectosigmoid endometriosis.