Focal Liver Lesions

Abstract

AbstractContrast-enhanced multi-phasic MDCT is the most important liver imaging technique in many institutions, when a focal lesion is suspected at ultrasound. Lesion characterization is based on size, shape, contour, and assessment of contrast enhancement pattern. If a lesion shows peripheral and nodular enhancement, with the density of enhancing portions similar to the vascular pool, a hemangioma can be confidently diagnosed. There are many different arterial-phase hypervascular lesions, include FNH, adenoma, HCC, and metastases from NET, melanoma, renal cell carcinoma, sarcoma, and breast cancer. Lesion characterization in general, HCC is considered in a setting of cirrhosis or chronic liver disease.An MR examination of the liver routinely includes unenhanced T1-weighted GRE DIXON, T2-weighted TSE fatsat, and diffusion-weighted imaging (DWI) as well as dynamic contrast-enhanced pulse sequences. 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, improve the characterization of FNH and adenoma, as well as the characterization of equivocal lesions in cirrhosis.