Sonographic evaluation of the rejecting ureter.

In 10 mongrel dogs, the sonographic features of the pelvocaliceal system and ureteral peristalsis during acute rejection were correlated with the electromyographic (EMG) findings and histologic appearance. There were significant alterations of the ureteral dynamics during rejection as demonstrated by changes in the pressure tracings, the progressive decrease of electrical activity of the ureteral muscle, and decreased peristalsis with pelvicaliectasis as demonstrated on real-time ultrasound. The sonographic changes of peripelvic and periureteral thickening corresponded to histologic changes of edema and inflammatory infiltrate with disruption of the muscular layer. In the presence of clinical and sonographic findings of kidney rejection, the demonstration of hydronephrosis and thickened pelvic wall should be considered as another measure of the rejection process.