Abstract
One milestone in the history of medicine was the discovery of x-rays by Wilhelm Conrad Roentgen in 1895. This led to the examination of the human body by an indirect method. It was soon learned that internal organs which were diseased could cast an abnormal shadow on an x-ray film. It was further learned that more detailed studies could be made of internal organs by the use of radiopaque material. The first of the internal organs to be studied by this method was the gastro-intestinal tract by the use of a bismuth compound taken orally. This was done within two years from the time of Roentgen’s original work. | Almost at the same time, as early as 1897, Tuffier, by using a combination of an opaque ureteral catheter and radiography, was able to demonstrate a ureteral calculus (l). From that time until the late twenties, all of the urography carried out was by use of retrograde, opaque media. In 1929, an intravenous iodide, IopaxR (Uroselectan), was introduced by Swick (2). This dye was found to be selectively concentrated and excreted by the kidneys, making their radiographic visualization possible, and serving secondarily as a test of renal function. One serious hazard, however, to any of the intravenous iodides is that there can be some untoward side effects, even to the point of causing death in a few cases. Although renal opacification with most any of the dyes is usually quite satisfactory, it is their side effects that are most undesirable.