Dynamic magnetic resonance imaging of the female pelvis: radio-anatomy andpathologic applications. Preliminary results

Dynamic MRI of the pelvis was performed in 16 young nulliparous, normally c ontinent women. The examinations were performed in the dorsal decubitus pos ition. Using Turbo-Flash scans (acquisition time: 2.1 sec), sagittal images were obtained at rest and with maximal pelvic straining. The sacral promon tory-subpubic (PSP) and the subpubic-subsacral axes (SPSS) measured respect ively 80.5 degrees and 30 degrees in relation to the horizontal plane, with out a statistically significant difference between rest and straining. A ma rked deformation of the posterior wall of the bladder was observed in 13 ca ses and the bladder neck was frontally deformed in 10 cases. With straining , the base of the bladder did not descend beyond 15 mm below the SPSS, and the cervix stayed at least 14 mm above the SPSS. These were established as the normal criteria for pelvic assessment. 20 multiparous patients (mean ag e 65 years), referred for urinary stress incontinence and /or prolapse, wer e investigated using the criteria previously established. The PSP, SPSS, an d vaginal angle measured 80.95 degrees, 30.57 degrees, and 69.69 degrees re spectively in relation to the horizontal. No statistically significant diff erence was detected between straining and rest conditions. The angle of the uterus in relation to the horizontal was 57.36 degrees at rest and 65.90 d egrees in straining with a difference that was statistically significant. i n six patients, the base of the bladder descended more than 1.5 cm while st raining and in seven patients the cervix descended at least 1.4 cm below th e SPSS while straining, both statistically significant differences. Overall , between our control and study populations, there were no significant diff erences between PSP and SPSS measured on straining and at rest. However, di fferences were detected in the vaginal angle, bladder-base position, and ce rvical position. These results suggest the potential substitution of MRI fo r colpocystography.