Published online Mar 27, 2015. doi: 10.4254/wjh.v7.i3.468
Peer-review started: August 30, 2014
First decision: September 30, 2014
Revised: October 10, 2014
Accepted: December 3, 2014
Article in press: December 3, 2014
Published online: March 27, 2015
Noninvasive imaging has become the standard for hepatocellular carcinoma (HCC) diagnosis in cirrhotic livers. In this review paper, we go over the basics of MR imaging in cirrhotic livers and describe the imaging appearance of a spectrum of hepatic nodules marking the progression from regenerative nodules to low- and high-grade dysplastic nodules, and ultimately to HCCs. We detail and illustrate the typical imaging appearances of different types of HCC including focal, multi-focal, massive, diffuse/infiltrative, and intra-hepatic metastases; with emphasis on the diagnostic value of MR in imaging these lesions. We also shed some light on liver imaging reporting and data system, and the role of different magnetic resonance imaging (MRI) contrast agents and future MRI techniques including the use of advanced MR pulse sequences and utilization of hepatocyte-specific MRI contrast agents, and how they might contribute to improving the diagnostic performance of MRI in early stage HCC diagnosis.
Core tip: Noninvasive imaging has become the standard for hepatocellular carcinoma (HCC) diagnosis in cirrhotic patients. Typical imaging features of HCC, including increased arterial enhancement and delayed washout, provide very high specificity and acceptable sensitivity in characterizing even very small nodules. Diagnostic limitations apply to detecting hypovascular HCCs and differentiating high-grade dysplastic nodules from early HCCs. New techniques such as diffusion-weighted images, T2*, and hepatocyte-specific magnetic resonance imaging contrast agents, are being currently evaluated, which might improve future detection and characterization of hepatic lesions when combined with the current standard imaging protocols with dynamic imaging.