ReviewPrimary benign liver lesions

- An overview of US, CT and MRI appearance of benign focal liver lesions is given.
- The possible differential diagnosis between benign lesions and between benign and malignant lesions are pointed out.
- The fundamental role of MRI with extracellular and hepatobiliary contrast agents is underlined.

Benign focal liver lesions can origin from all kind of liver cells: hepatocytes, mesenchymal and cholangiocellular line. Their features at imaging may sometimes pose difficulties in differential diagnosis with malignant primary and secondary lesions. In particular, the use of MDCT and MRI with extracellular and hepatobiliary Contrast Agents may non invasively help in correct interpretation and definition of hepatocellular or mesenchymal and inflammatory nature, allowing to choose the best treatment option. The peculiarities of main benign liver lesions at US, CT and MRI are described, with special attention to differential diagnosis and diagnostic clues.