Nuclear medicine and ultrasound; correlation in diagnosis of disease of liver and biliary tract.

Even though the radiocolloid scan is nonspecific it will be approximately 70%-80% accurate in predicting the presence or absence of liver disease and somewhat less accurate than that in making statements as to the specific type of disease. This compares well with other modalities. The ability of nuclear medicine techniques to provide a correct diagnosis is improved when additional isotopic techniques such as hepatic blood flow studies and 131I-rose bengal and 67Ga scanning are performed. Ultrasound scanning is also non specific. To date, the major application of ultrasound in the study of the liver has been in deciphering puzzling contour abnormalities seen on nuclear medicine scans and in demonstrating fluid-filled abnormalities. Its usefulness in diffuse and solid focal lesions has been less dramatic. More recently, however, the development of gray scale has necessitated a reevaluation of the technique. Gray scale demonstrates a large number of intrahepatic interfaces that were previously invisible, and it has already been shown to demonstrate focal disorders such as metastasis more easily than the nongray-scale method. It can also demonstrate dilated biliary radicals, the gallbladder, and gallstones. In addition, while routinely studying the liver one can evaluate diaphragmatic motion and various retroperitoneal structures such as the pancreas, lymph nodes, and abdominal vascular structures.