Videourodynamics using transperineal Doppler ultrasonography

A totally noninvasive transperineal urodynamic technique using Doppler ultrasonography has been developed. Since normal urine does not have blood cells, urine was thought not to produce the Doppler effect. However, basic studies confirmed that the decrease of pressure at high velocity (Bernouilli effect) caused dissolved gas to form microbubbles, which are detected by Doppler ultrasonography. Subjects sat and the probe was advanced via remote control to achieve gentle contact with the perineal skin. The color Doppler video images and uroflow data were processed to measure urinary velocity related parameters. This method is viable to diagnose the degree of bladder outlet obstruction and sphincteric function.