Feasibility Study on Non-Invasive Methods for Bladder Biomechanics During Voiding Using Uro-Dynamic MRI.

Background: Uro-Dynamic MRI is a non-invasive protocol used to evaluate/analyze bladder contraction. Regionalized anatomical measurements and multi-variate linear regression models (MVLRM) were used to establish a methodology to evaluate bladder contraction. Methods: In this exploratory study, five healthy subjects and six LUTS patients underwent Uro-Dynamic MRI during voiding. Bladders were segmented at each time point during the void. Volume (V) and surface area (SA) were recorded, resulting in urinary flow rate (Q) and sphericity index (SI) curves. Regionalized anatomical measurements were tracked and linearly correlated with Q, while symptom scores from the International Prostate Symptom Score Survey (IPSS) were correlated using MVLRM. Results: Healthy subjects exhibited high linear correlation of contraction with Q; the opposite was observed in LUTS patients. The occurrence of SImax coincided within two time points of Qmax for 80% of healthy subjects and 50% of LUTS patients. MVLRM identified SI, transverse and anteroposterior lengths as correlates of LUTS diagnosis and urinary frequency. Conclusions: This methodology revealed distinct, biphasic patterns of bladder contraction during voiding and showed associations between symptomatic behavior and anatomical measurements. This exploratory study demonstrated a comprehensive methodology to non-invasively quantify patient-specific bladder contraction patterns during voiding that could provide physicians with relevant information on symptom-specific treatment.