Usefulness of Dynamic MRI in Diagnosis of Stress Urinary Incontinence

Lee, Ji Youl; Kim, Sae Woong; Park, Wang Jin; Jung, Woong Gyo; Lee, Seung Ju; Jung, Seung Eun; Cho, Yong Hyun; Yoon, Moon Soo

Abstract

PURPOSE: We aimed to define supine static and dynamic magnetic resonance imaging (MRI) appearance of changes in bladder neck and levator ani muscle and find out clinical significance of this method from comparing with valsalva leak point pressure (VLPP) in patients with stress urinary incontinence.
MATERIALS AND METHODS
Sixty patients were studied with supine static MR imaging through volumetric axial and sagittal pelvic imaging in the first and second procedures and then were examined with dynamic MR imaging through resting/straining midline sagittal imaging in the third procedure. We evaluated the changes in bladder neck and levator ani muscle of stress urinary incontinence patients from these MR imaging. Patients were divided into two groups according to their responses to VLPP; the group 1 (n=20) with VLPP below 60cmH2O and the group 2 (n=40) with VLPP over 60cmH2O. We analyzed the data taken from comparing MR imaging results with VLPP results.
RESULTS
Regarding the degree of changes in bladder neck compared with the results of supine static and dynamic MRI, there were beak shaped changes in the bladder neck in 15 patients from group 1 (75.0%) and especially, in the rest 5 patients excluding 3 patients who had severe cystocele, we could observe 88.2% of beak shaped changes. Beak shaped changes were seen in 5 patients (12.5%) and funnel shaped change or non-specific changes in the rest cases from group 2 (p<0.0001). We could observe the degenerative changes of levator ani muscle in 41 patients from overall (68.3%), which means 13 patients from group 1 (65.0%) and 28 patients from group 2 (70.0%), respectively.
CONCLUSIONS
Supine static MRI enables to observe degenerative changes in pelvic floor muscle of stress urinary incontinence while dynamic MRI is deemed to be a relatively comfortable and non-invasive diagnostic method for stress urinary incontinence especially complementing VLLP.