Magnetic resonance imaging of the perineum and pelvic floor.

The aim of this article is to review the magnetic resonance (MR) findings of pelvic floor descent and pelvic organ prolapse in women. In addition, a detailed grading system of pelvic organ prolapse and pelvic floor relaxation based on dynamic MR imaging is presented. The technique described here uses very fast MR sequences, is reproducible and easily learned by radiologists and technologists, is well accepted by patients, and provides as much information as traditional projectional X-ray imaging. Reference points are the pubococcygeal line and puborectalis muscle sling. The grading system is based on degree of organ prolapse through the hiatus and the degree of puborectalis descent and hiatal enlargement.