Dynamic cystocolpoproctography is superior to functional pelvic MRI in the diagnosis of posterior pelvic floor disorders: results of a prospective study

Aim: The accuracy of dynamic cystocolpoproctography (DCP) and dynamic MRI were compared in diagnosing posterior pelvic floor disorders.

Method: Fifty consecutive female patients (mean age 51 years) complaining of posterior compartment pelvic floor disorder and referred to a tertiary centre entered the prospective study. The Institutional Review Board stated that informed consent from the patients was not necessary for this study. Patients underwent a DCP and a supine functional MRI by two different radiologists. Assessment of radiological examinations was prospective and blind. All patients underwent surgery that led to the final diagnosis. Agreement between the operative diagnosis and the diagnoses following DCP and MRI was assessed using the weighted kappa statistic. A matched-pairs McNemar's test was applied to demonstrate whether or not one radiological method was superior to the other.

Results: Full-thickness rectal prolapse was best diagnosed by clinical examination. Internal rectal prolapse and peritoneocele were best diagnosed by DCP. A better agreement with the operative diagnosis, which is not true superiority, was observed for DCP compared with functional pelvic MRI for full-thickness rectal prolapse, internal rectal prolapse and peritoneocele. There was no significant difference between DCP and functional pelvic MRI in the diagnosis of internal rectal prolapse (P = 0.125) or peritoneocele (P = 0.10).

Conclusion: As full-thickness rectal prolapse, internal rectal prolapse and peritoneocele might be missed by functional pelvic MRI, there should still be a place for DCP in particular cases where the clinical diagnosis is not clear in women with symptomatic posterior pelvic floor disorders.