LAMINAR SUBMERGED JETS BY COLOR DOPPLER ULTRASOUND - A MODEL OF THE URETERAL JET PHENOMENON

RATIONALE AND OBJECTIVES. The authors developed and tested a technique to noninvasively measure ureterovesical junction (UVJ) pressure gradients. Such a technique could be used to evaluate ureteral reflux and obstruction. METHODS. Color Doppler ultrasound measurements of an in vitro model of the ureteral jet were performed. RESULTS. The authors show that the orificial rate of momentum transfer of the ureteral jet (from which the intraluminal pressure in the ureter can be calculated) can be determined to within 45% to 94% of its true value depending primarily on the flow sensitivity of the color flow imager. Marked improvement in the momentum calculation (>80%) is achieved when a low-flow sensitivity is used. CONCLUSION. Such noninvasive measurements could replace more invasive techniques (eg, the Whitaker test or cystoscopy with or without ureteral cannulation), which seriously perturb the system of interest.