Focal Liver Lesions

Excerpt

Contrast-enhanced multiphasic MDCT is the most important liver imaging technique in many institutions. When evaluating solid focal liver lesions, disease characterization is based on assessment of contrast enhancement pattern. If a lesion shows peripheral and nodular enhancement, with the density of enhancing portions similar to the vasculature, a hemangioma can be confidently diagnosed. Arterial phase hypervascular lesions include FNH, adenoma, HCC, and metastases from NET, melanoma, renal cell carcinoma, and (sometimes) breast cancer. In general, HCC is considered in a setting of cirrhosis or chronic liver disease. An MR examination of the liver routinely includes dynamic contrast-enhanced pulse sequences and diffusion-weighted imaging (DWI). DWI’s main clinical benefit is the detection of focal liver lesions, which may be missed on conventional and contrast-enhanced imaging sequences. Liver-specific MR contrast agents have been shown to increase the detection of liver metastases and improve the characterization of FNH and adenoma, as well as the characterization of equivocal lesions in cirrhosis.