This technique uses radioactive tracers to visualize internal body structures which take up certain macromolecules which are radio labeled and, thus, are detectable by radionuclide scans. The commonly used scans include bone, cardiac, liver/spleen, and pancreatic. An abnormal nonhomogeneous scan is a nonspecific finding indicative of parenchymal liver disease. These scans are better techniques because they are essentially noninvasive ways of visualizing anatomical structures which, in conjunction with other techniques, may provide diagnostic evidence that would otherwise be unavailable.

Fiberoptic endoscopy permits the visualization of internal linings of hollow organs accessible via the transoral or transanal route. It is a better diagnostic tool because it provides for the direct visualization of mucosal erosions, ulcers, mass lesions, fistulae, bleeding sources, and obstructive lesions in the gastrointestinal tract and bronchial tree. Biopsies may be obtained for histologic confirmation of lesions. Endoscopic retrograde cholangiopancreatography (ERCP) requires the injection of radiopaque dye into the pancreatic and biliary ducts through the endoscope and permits visualization of biliary or pancreatic ducts radiographically. The test is used for detection of lesions of the biliary and pancreatic ducts. Percutaneous transhepatic cholangiography is an alternative technique to visualize the biliary system. This procedure requires the injection of dye through a needle rather than through endoscopy. Which procedure is utilized depends on the available facilities.

The CAT scan has made it possible to produce cross-sectional x ray images of the internal structures of the body. The CAT scan not only provides the cross-sectional x ray images, but the sensitivity and resolution are so great that small differences in x ray absorption can be detected so that it is possible to differentiate various types of soft tissues and detect small concentrations of contrast material within blood vessels. The CAT scan is most appropriate and sensitive for the detection of mass lesions, usually tumors. It is also possible to define anatomic defects such as cerebral infarcts, dilatation of ducts, and the presence of fluid in the pericardial, pleural, or peritoneal cavities. Its impact on the evaluation of impairments is to provide a noninvasive means for the detection of lesions in a multitude of organ systems.

This is a special radiologic imaging technique which increases the radiodensity of blood over that of surrounding structures and, therefore, increases the resolution of the radiographic images of blood vessels. The scanning technique allows dye to be injected intravenously to visualize, by x rays, the aorta, coronary, renal, and iliac vessels in order to estimate the blood flow in these vessels or the presence or absence of obstructive lesions. It is an improved technique because it can be performed on an outpatient basis with less risk and less discomfort to the patient than direct arteriography. In some cases, this technique will permit the exclusion of direct arteriography.