In 1923 Rowntree and his co-workers1 of the Mayo Clinic were the first to attempt to visualize the urinary tract by means of the intravenous injection of a 10 per cent solution of sodium iodide and also by the oral administration of that salt. The urinary bladder, and in some cases the pelvis and ureter, could be visualized.
The following year Rosenstein and von Lichtenberg2 reported at the urologic congress in Berlin their results, repeating the work of Rowntree and his co-workers with sodium iodide but in conjunction with perirenal pneumoradiography.
In the same year Volkmann3 reported his observations with the use of different halogen compounds; he found the intravenous injection of a 10 per cent solution of sodium iodide to be best.
In 1927 Lenarduzzi and Pecco,4 tying off the ureter and injecting sodium iodide intravenously in animals, obtained positive roentgenograms of the kidney, pelvis