Magnetic resonance imaging of pelvic organ prolapse: comparing pubococcygeal and midpubic lines with clinical staging

Abstract

The aim of the study was to determine which magnetic resonance imaging (MRI) reference line for staging pelvic organ prolapse, the pubococcygeal line (PCL) vs. the midpubic line (MPL), has the highest agreement with clinical staging. A retrospective study of women with pelvic floor complaints who underwent dynamic pelvic MRI from January 2004 to April 2007 was conducted. Two radiologists staged descent on MRI for each pelvic compartment (anterior, apical, posterior) by consensus, using PCL and MPL reference lines. Agreement between MRI and clinical staging was estimated using weighted kappas. Twenty women were included. Agreement between clinical and PCL staging was fair in the anterior (kappa = 0.29) and poor in the apical (kappa = 0.03) and posterior (kappa = 0.08) compartments. Agreement between clinical and MPL staging was fair in the anterior (kappa = 0.37), apical (kappa = 0.31), and posterior (kappa = 0.25) compartments. The MPL has higher agreement with clinical staging than the PCL. However, neither reference line has good agreement with clinical staging.