Within one year of Wilhelm von Roentgen's epoch-making discovery of the x-ray, Haschek and Lindenthal1announced the visualization of blood vessels in an amputated arm by means of a contrast medium. The latter proved to be toxic for clinical use, however, and it was not until Cameron2reported the radiopaque property of the iodide molecule that clinical vascular visualization became feasible. Brooks3began to employ this modality for studying peripheral vascular diseases, and shortly thereafter Moniz4introduced cerebral angiography. It remained, however, for Dos Santos and his collaborators5to first realize and apply the translumbar route of arteriography. The procedure was not generally adopted by American physicians until Nelson6and Doss7independently published their experiences with translumbar aortography. Today, aortography is used extensively as a valuable diagnostic adjunct for the investigation of pathological conditions of the kidneys, retroperitoneal structures, and major arteries. The