Abstract
Urodynamics comprises urine flow testing, ultrasound estimation of post-void residual, and Cystometry with filling and voiding phases [1]. Cystometry is the concurrent pressure measurement from the bladder and an abdominal control site, with parallel urine flow measurement. Using conventional water filled catheters, pressures are referenced to atmospheric pressure and the physical height of the external pressure transducer. Cystometry facilitates assessment of detrusor strength, and weakness or obstruction in the tract below.
Video Urodynamics (VUDS) adds fluoroscopy to these physiological measurements, and allows differential diagnosis of pathology in Stress Urinary Incontinence (SUI) as well as surveillance of upper tract integrity [2]. A cysto-urethrogram is a non-invasive alternative to VUDS, allowing the whole urinary tract to be visualised during micturition. [3] It sacrifices pressure data, but can include a measurement of flow rate [4]