Screening for diffuse and focal liver disease: the case for hepatic computed tomography.

I believe that CT should usually be the first choice for examining patients with suspected liver disease. Precontrast scans may suffice when results are clearly abnormal, but when contrast is given it should be in a high dose, bolus injection with rapid sequential scanning and table incrementation. This opinion is based upon: (1) the greater sensitivity and specificity of contrast enhanced CT compared to sonography and radionuclide scanning in focal liver lesions; (2) the ability of CT to detect diffuse liver abnormalities; (3) the greater ease in standardizing the CT examination and interpretation; (4) the ability of CT to predict accurately the histology of many focal and diffuse liver diseases; and (5) the superiority of CT in accurately detecting and characterizing extrahepatic abnormalities. The advantages of CT are somewhat mitigated by its limited availability, and relatively greater risk and cost, but these factors are often overcome by facilitating diagnosis and management by more accurate initial evaluation. Sonography may be done first when fast CT scanners are not available, when intravenous contrast cannot be administered satisfactorily, when other problems arise with technique, for patients requiring sonography for other reasons, or when delays for scheduling CT scans are too long. Radionuclide liver-spleen scanning should play a very limited role in the early evaluation of liver disease, being reserved for occasionally clarifying the presence of diffuse liver disease, or for patients difficult to study either by CT or sonography.