The history of uroradiology.

In the first period (1896-1910), investigation was made through plain abdominal film with description and differential diagnosis of the different calcifications in the right hypochondrium. Second period (1911-1924): indirect signs of liver and gallbladder pathology were described. Via pneumoperitoneum and gastro-intestinal opacification the pathology in the right hypochondrium was delineated and interpreted. Third period (1924 until now): due to the development of contrast agents for the gallbladder and biliary tree, these organs could be directly visualized either by intravenous injection, or by peroral administration; sometimes direct injection of contrast in the bile ducts was used.