Modified MR defecography without rectal filling in obstructed defecation syndrome: Initial experience

To evaluate the role of dynamic MR defecography before rectal filling in detecting occult anterior compartment prolapse in patients with obstructed defecation.

This prospective study was approved by the ethics committee. Seventy six females with obstructed defecation underwent dynamic MR defecography before and after rectal filling. Pre-rectal and post-rectal filling sequences were interpreted separately by two radiologists on two different settings with a time interval of one week. Statistical analysis was performed using Wilcoxon's-matched-pairs signed rank test and t-test for matched pairs; differences were considered statistically significant at p<0.05.

Fifty eight females of 76 showed additional anterior compartment derangement, with 27 diagnosed only in pre-rectal filling sequence (27/58=46.55%). Following rectal filling detected cystocele in 27 patients was not identified in 14 cases and downgraded in 13. Similarly, detected uterine prolapse in 17 patients was not visualized in 14 patients and downgraded in 3. Furthermore, rectocele was identified in 7 cases before gel enema, additional 32 detected after rectal filling. Significant statistical difference in the detection of both cystocele (p=0.0001) and uterine prolapse (p=0.0013) was identified in the non-filled sequence.

Pelvic floor imaging before rectal filling is significantly better for detection of anterior compartment prolapse.