Spectrum of CT and sonographic appearance of fatty infiltration of the liver.

This report presents the common and unusual appearances of fatty infiltration of the liver (FIL) on ultrasound (US) and computerized tomography (CT) from pathological, proven cases. Potential diagnostic pitfalls and methods of avoiding these pitfalls will be emphasized. Generalized and the geographic pattern of FIL are well recognized. Focal FIL and focal sparring of the liver have a number of atypical appearances. Focal sparring has several distinct patterns (pseudotumor, glove pattern and possible metastasis), which may be confused with other pathologies. Likewise, focal FIL may simulate a space-occupied mass. Among the more helpful features used to distinguish focal FIL from other abnormalities include its lack of mass effect, low density on CT combined with increased echogenicity on US.