Study of uterine prolapse by magnetic resonance imaging: topographical changes involving the levator ani muscle and the vagina.

Alternations of the pelvic structure with an emphasis on those of the levator ani muscle, associated with uterine prolapse, were studied using sagittal magnetic resonance images obtained from 19 subjects without and 14 with uterine or vaginal prolapse of varied degree and 3 patients with Rokitansky syndrome who had undergone a McIndoe operation. Two additional patients with a grade III uterine prolapse were also studied before and 2-3 months after corrective surgery consisting of vaginal hysterectomy combined with anterior colporrhaphy and posterior colpoperineorrhaphy. Absence or presence of prolapse, irrespective of its grade, was found to be related to whether or not a reference line extrapolated from the levator plate crossed the pubis on sagittal images. This was the case as well in patients with Rokitansky syndrome with a neovagina and loss of such crossings was restored in patients with prolapse after surgery. Backward bending of the upper vagina noted in nonprolapse conditions was usually absent in patients with uterine prolapse. These results document that topographical changes involving the levator ani muscle and the vagina occur in association with uterine prolapse.