Role of static and dynamic MRI in evaluation of pelvic posterior compartment pathologies: prospective case series

Abstract

Background: Pelvic floor dysfunction affects the lifestyle of women worldwide; the aim of this study is to evaluate the role of static MRI and dynamic MR defecography in the diagnosis of the posterior compartment of pelvic floor dysfunction. This prospective study included 50 female patients. All of them presented with pelvic floor dysfunction. Static and dynamic MRI were performed for all patients after injection of 120–150 ml of intrarectal gel and voiding 2 h before examination. Dynamic MRI was performed at rest, squeezing, straining phases, and during defecation. Results: MR defecography can detect posterior compartment pathology with high sensitivity and specificity. We found anterior rectocele in 26 patients (52%). Rectocele incidence was analyzed and compared to postoperative reports, and the receiver operator curve (ROC) was calculated that showed area under the curve (AUC) of 0.998. The cut-off value of 1.95 cm gives a sensitivity of 96.4% and specificity of 100% during straining. The percentage of anismus was 26%, rectorectal intussusception 52%, anal prolapse types (rectoanal intussusception 14% and external prolapse 8%), and peritoneocele 34%. Conclusion: MRI is a valuable imaging modality that can be used to diagnose pelvic floor disorders and does not involve the risk of exposure to ionizing radiation. It can direct the surgical procedure and thus improve the post-operative results and decrease the rate of recurrence due to missed pathology.