Assessment and grading of pelvic organ prolapse by use of dynamic magnetic resonance imaging

OBJECTIVE: Our purpose was to assess and compare a new technique of grading pelvic organ prolapse by using dynamic magnetic resonance imaging with the clinical staging proposed by the International Continence Society. STUDY DESIGN: In a cross-sectional study, 20 patients with pelvic organ prolapse underwent dynamic magnetic resonance imaging. Clinical staging (according to the International Continence Society) was compared with staging by magnetic resonance imaging. A new reference line, the midpubic line, was drawn on the magnetic resonance image to correspond to the hymenal ring marker used in the clinical staging. The levator-vaginal angle and the area of the genital hiatus were measured to indicate vaginal supports. Ten nulliparous, symptom-free women were studied as control subjects. RESULTS: The proposed staging by magnetic resonance imaging showed good correlation with the clinical staging (K = 0.61). Magnetic resonance Imaging improved clinical assessment by its ability to measure the actual pelvic organ descent and to delineate prolapse of the pouch of Douglas accurately. The midpubic line was a useful reference line for grading prolapse on magnetic resonance imaging. The levator-vaginal angle and the area of the genital hiatus are useful in assessing vaginal support at different anatomic levels. CONCLUSIONS: This new method of grading by magnetic resonance imaging uses the same landmarks as the clinical grading, and this uniformity of approach allows an objective assessment of the results of surgical correction of pelvic organ prolapse.