Critical soft tissues of the female pelvis: serial MR imaging before, during, and after radiation therapy

To evaluate the findings in the irradiated critical soft-tissue organs of the female pelvis at magnetic resonance (MR) imaging within 30 months after radiation therapy.

Twenty-three patients (13 premenopausal and 10 postmenopausal women) with advanced cervical carcinoma underwent 276 MR examinations (T1- and T2-weighted imaging) scheduled before, three times during, and 7 weeks and 3, 6, 9, 12, 18, 24, and 30 months after the end of radiation therapy. A visual evaluation of the ureters, bladder, rectum, parametrium, and perivesical and perirectal soft tissues was performed by two radiologists.

Fifteen abnormally wide ureters (diameter range, 7-23 mm; mean diameter, 14 mm) were seen in 10 (seven premenopausal and three postmenopausal women) (43%) of 23 patients at a median time of 18 months after the end of radiation therapy (range, 9-30 months). An abnormally wide ureter was a transient finding in eight (53%) of 15 abnormal ureters. Two premenopausal women (9%) of 23 patients had rectovaginal fistulas. One of these two patients also had a vesicovaginal fistula.

Ureteral dilatation was seen in nearly half of the patients and occurred more frequently in premenopausal women than in postmenopausal women. Knowledge about the appearances of radiation-induced abnormalities of the critical soft tissues may be of help in the interpretation of MR images of the pelvis.