Technical feasibility of uro-dynamic MRI study of voiding biomechanics: a pilot study.

INTRODUCTION: Dynamic volumetric MRI was used to non-invasively assess voiding biomechanics in a healthy male volunteer. METHODS: Using 3D Differential Subsampling with Cartesian Ordering (DISCO) Flex acquisition sequence, volumetric bladder images were obtained throughout the voiding effort. These were subsequently segmented using MIMICS. Segmented anatomical volumes were used to quantify total voided volume, post-void residual, volumetric displacement of urine over time, bladder neck angle, sphericity index, and prostatic urethral angle through the voiding effort. RESULTS: Bladder sphericity index correlated positively with flow rate. The greatest degree of bladder neck funneling correlated with the maximum urine flow rate. There was straightening of the prostatic urethral angle during voiding that also correlated positively with urine flow. CONCLUSION: This pilot study confirms the potential of dynamic MRI to provide non-invasive assessment of lower urinary tract anatomy and biomechanics during voiding.