Ultrasonography of jaundice.

Ultrasonography is proposed as a valuable first step in the study of the jaundiced patient. Utilizing modern gray scale technology, it is nearly always possible to determine whether or not dilatation of the biliary tree is present. In the presence of diffuse liver disease without obstruction, some assessment of the state of the parenchyma can often be made. In patients with obstruction, its severity and level are usually easy to determine. It may be considerably harder to correctly diagnose the etiology of the obstruction, and more invasive investigations will then be required.