The application of computed tomography (CT) for diseases of the liver, pancreas, kidney, and retroperitoneum has been described. The diagnostic accuracy of CT when compared with angiography, radioisotope scanning, endoscopic pancreatography, and transhepatic cholangiography is now being studied prospectively. The attractive features of CT include low risk, wide applicability, noninvasive technics, high diagnostic accuracy, and patient acceptance.