Urogenital kinematics mesaured in the sagittal plane using a novel ultrasound image processing approach

Stress urinary incontinence (SUI) is highly prevalent among women, and is associated with biomechanical defects in the urogenital system. Current approaches to quantifying urogenital mechanics are limited. The purpose of this research is to develop semi-automated software that compensates for in-plane translational and rotational probe motion during kinematic analyses based on dynamic sagittal-plane ultrasound imaging. Coordinate systems were constructed in each video frame in order to build transformation matrices that would compensate for probe motion. Once the transformation matrices were applied to each frame, kinematics could be calculated. The kinematics of the bladder neck (BN) and anorectal angle (ARA) were calculated in a female presenting with mild SUI performing a double-barrel cough. Displacement and velocity curves were similar to those reported in the literature, while accelerations were difficult to compare due to differences between our task and the only task analyzed in the literature. The results appear to reflect adequate pelvic floor muscle activation, indicating that in this woman, SUI may be due to another urogenital defect, such as urethral hypermobility or sphincter deficiency. This paper presents a proof of concept for software development. As a next step, inter-and intra-user reliability of the software output will be evaluated.