Magnetic resonance defecography versus videodefecography in the study of obstructed defecation syndrome: Is videodefecography still the test of choice after 50 years?

Abstract

The aim of the present study was to evaluate the diagnostic accuracy of magnetic resonance (MR) defecography and compare it with videodefecography in the evaluation of obstructed defecation syndrome. This was a prospective cohort test accuracy study conducted at one major tertiary referral center on patients with a diagnosis of obstructed defecation syndrome who were referred to the colorectal surgery clinic in a consecutive series from 2009 to 2012. All patients underwent a clinical examination, videodefecography, and MR defecography in the supine position. We analyzed diagnostic accuracy for MR defecography and performed an agreement analysis using Cohen's kappa index (κ) for each diagnostic imaging examination performed with videodefecography and MR defecography. We included 40 patients with Rome III diagnostic criteria of obstructed defecation syndrome. The degree of agreement between the two tests was as follows: almost perfect for anismus (κ=0.88) and rectal prolapse (κ=0.83), substantial for enterocele (κ=0.80) and rectocele grade III (κ=0.65), moderate for intussusception (κ=0.50) and rectocele grade II (κ=0.49), and slight for rectocele grade I (κ=0.30) and excessive perineal descent (κ=0.22). Eighteen cystoceles and 11 colpoceles were diagnosed only by MR defecography. Most patients (54%) stated that videodefecography was the more uncomfortable test. MR defecography could become the imaging test of choice for evaluating obstructed defecation syndrome.