MR defecography in patients with fecal incontinence: Imaging findings and their effect on surgical management

Purpose: To retrospectively evaluate magnetic resonance (MR) defecography findings in patients with fecal incontinence who were evaluated for surgical treatment and to assess the influence of MR defecography on surgical therapy. Materials and Methods: Institutional review board approval was obtained. Informed consent was waived; however, written informed consent for imaging was obtained. Fifty patients (44 women, six men; mean age, 61 years) with fecal incontinence were placed in a sitting position and underwent MR defecography performed with an open-configuration MR system. Midsagittal T1-weighted MR images were obtained at rest, at maximal contraction of the sphincter, and at defecation. Images were prospectively and retrospectively reviewed by two independent observers for a variety of findings. Interobserver agreement was analyzed by calculating kappa statistics. Prospective interpretation of MR defecography findings was used to influence surgical therapy, and retrospective interpretation was used for concomitant pelvic floor disorders. Results: MR defecography revealed rectal descent of more than 6 cm (relative to the pubococcygeal line) in 47 (94%) of 50 patients. A bladder descent of more than 3 cm was present in 20 (40%) of 50 patients, and a vaginal vault descent of more than 3 cm was present in 19 (43%) of 44 women. Moreover, 17 (34%) anterior proctoceles, 16 (32%) enteroceles, and 10 (20%) rectal prolapses were noted. Interobserver agreement was good to excellent (kappa = 0.6 - 0.91) for image analysis results. MR defecography findings led to changes in the surgical approach in 22 (67%) of 33 patients who underwent surgery. Conclusion: MR defecography may demonstrate a variety of abnormal findings in patients who are considered candidates for surgical therapy for fecal incontinence, and the findings may influence the surgical treatment that is subsequently chosen. kappa RSNA, 2006.