The purpose of this study was to assess the incidence, time of appearance, and evolution of radiation-induced insufficiency fractures of the female pelvis with MR imaging.Eighteen women (nine premenopausal and nine postmenopausal) with advanced cervical carcinoma were studied prospectively with MR imaging. The examinations totaled 216 and were scheduled before radiation therapy, three times during radiation therapy, and eight times after radiation therapy. T1-weighted and short inversion time inversion recovery images were obtained. The images were evaluated by two radiologists in consensus. The criterion for fracture was edema, indicated by an area of high signal intensity on short inversion time inversion recovery images and corresponding low signal intensity on T1-weighted images. CT scans (n = 61) and bone scans (n = 58) were used to confirm each diagnosis of fracture.Sixteen (89%) of 18 patients (seven premenopausal and nine postmenopausal) showed findings compatible with insufficiency fractures. Thi...