/sup 99m/pertechnetate uptake in the transplanted kidney. [/sup 99m/Tc, /sup 133/Xe, /sup 131/I, /sup 203/Hg]

Acute renal failure is a common complication of kidney transplantation. The major causes are acute tubular necrosis (ATN), arterial or venous thrombosis, rejection, ureteral obstruction, and extravasation. Each situation requires a different treatment and demands prompt diagnosis to prevent loss of the graft and patient morbidity or mortality. The clinical problem is further complicated by the possible coincidence of more than one of these pathologies, in particular the development of graft rejection superimposed on ATN in the post-transplant period. The diagnostic studies used in this differential diagnosis may include retrograde ureteral catheterization, renal arteriography, open or closed renal biopsy, isotope studies with /sup 133/xenon, /sup 131/I-hippuran, /sup 203/Hg-chlormerodrin, and more recently /sup 99m/pertechnetate. Only the latter methods with hippuran, chlormerodrin, and pertechnetate avoid direct manipulation of the graft or its artery or ureter with the inherent risks of such procedures. We present results of serial studies of sodium /sup 99m/pertechnetate photoscanning(Tc scan) in 38 renal homografts. In some studies computer determined graphs of renal radioactivity versus time (Tc renogram) were obtained.