Magnetic imaging defecography results are comparable to high-resolution manometry and conventional X-ray defecography in the assessment of functional pelvic floor disorders

Background: X-ray defecography or magnetic resonance defecography (MRD) and high-resolution anorectal manometry (HR-ARM) are essential for the diagnosis of pelvic floor disorders (PFD). However, there is only scarce information available about the accuracy of MRD in the functional assessment of the pelvic floor. The aim of this study was to examine the accuracy of MRD in the diagnosis of pelvic floor disorders by examining the intra-test agreement with x-ray defecography and HR-ARM in patients with PFD. Methods: The study population included adults referred to our institution in January 2018–February 2020 for MRD as part of their evaluation of PFD. The MRD results were compared with X-ray defecography and HR-ARM. Results: Forty-two patients were included in the study (36 female, 86%, mean age 56.9 years ± 15.8, range 19–86 years). When compared to X-ray defecography, the sensitivity of MRD for the evaluation of normal rest and squeeze pressures was high (0.83 and 1, respectively). High sensitivity rates were observed for the detection of pelvic organ prolapse and pelvic floor dyssynergia (0.84–1). When compared to HR-ARM, the sensitivity of MRD for the evaluation of squeeze and dyssynergia was very good (0.92and 1, respectively), and good for the evaluation of rest pressure (0.6). Inter-test agreement was high (0.5, 0.6, 0.6 for rest, squeeze and dyssynergia). Excellent rates of sensitivity as well as almost perfect intra-test agreement was found between abnormal balloon expulsion test and the diagnosis of dyssynergia and pelvic organ prolapse on MRD (1, 0.81). Conclusions: This study demonstrated substantial diagnostic agreement between HR-ARM and MRD in the diagnosis of pathological etiologies for functional pelvic floor disorders, mainly obstructed defecation syndrome.