Computed radionuclide urogram for assessing acute renal failure.

The computed radionuclide urogram is advocated as a noninvasive diagnostic method for differentiation of the most common prerenal, renal, and postrenal causes of acute renal failure. On the basis of characteristic changes in the effective renal plasma flow rate, the calculated filtration fraction, and the calculated glomerular filtration rate, prerenal conditions such as renal artery stenosis or thrombosis, renal conditions such as acute rejection or acute tubular necrosis, and postrenal conditions such as obstruction or leakage, which are the most common causes of acute renal failure, can be differentiated. In conjunction with morphologic criteria derived from sonograms, a diagnosis with acceptable confidence can be rendered in most instances. Both the computed radionuclide urogram and sonogram are noninvasive and can be used without adverse effects in the presence of azotemia and even anuria. This also makes feasible reexamination at intervals to assess effect of therapy and offer prognostic information.