The time-distance diagram: a new method to analyze ureteral peristalsis by cineradiography

We assessed ureteral peristalsis in dogs by cineradiography and analyzed the films in a single frame follow-up by measuring the position of bolus front and rear end in relation to the bladder and the kidney. The data were plotted as function of time in a time-distance diagram. The bolus rear end which is the active contractile rings, as proven by electromyography, travels with constant velocity. The bolus front shows remarkable changes in propagation velocity which can be explained by differences in wall forces that resist the opening of the ureteral lumen. Thus, the time-distance diagram describes precisely the constantly changing dynamics of ureteral peristalsis along the entire ureter.