We believe that angiography provides a safe and valuable means to detect occult vascular pathology and viability of potential cadaver transplants. It is the only means by which one can determine whether complete perfusion of the kidney is achieved. Thrombi are easily detected. Clinical and experimental evidence suggest that in cases of increased peripheral resistance at least 2 angiographic patterns are observable. Where major vessel spasm is evident, the kidney is probably unsuitable for transplantation. When there is uniform angiographic perfusion of the kidney despite flow measurements that indicate increased peripheral resistance, the kidney may be suitable for transplantation. We suggest that contrast medium be completely flushed from the perfusate to eliminate prolonged contrast medium recirculation. We plan to evaluate all actual donors for human transplantation by this method. Xenon washout studies are also contemplated.