To describe the role of Gadoxetic acid in magnetic resonance imaging of: - Hepatocellular carcinoma (HCC) - Focal nodular hyperplasia (FNH) - Hepatic adenoma (HA) - Colorectal metastases To describe typical enhancement patterns, characteristic imaging features and the main differential diagnosis for these lesions after GA administration.

Gadoxetic acid (GA) is a contrast agent whose role in magnetic resonance imaging (MRI) has been growing. GA is a short name for gadolinium ethoxybenzyl diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA), a gadolinium-containing contrast agent with new imaging features. After an intravenous injection, 50% of the dose is distributed in the extracellular space, acting like extracellular contrast agents (ECA) and showing perfusion in lesions in the dynamic phases of MRI. The remaining 50% is actively captured by functional hepatocytes and is consequently secreted into the bile. In...

1. Imaging hepatocellular carcinoma (HCC) It should be highlighted that HCC is the only tumor which can be diagnosed based on noninvasive imaging techniques, without any histopathological confirmation. Therefore, it is important to know the criteria that need to be fulfilled to make the diagnosis. Recent guidelines by LI-RADS from 2014 has included GA in the noninvasive diagnosis of HCC [1] . In the diagnosis of HCC with GA, the arterial phase hyperenhancement is a major feature. Ideally, the images should be obtained in the...

MRI with GA: - has proved to facilitate the radiologic diagnosis of HCC, FNH, HA, and detect metastatic lesions at an early stage; - is included in the radiologic criteria for the diagnosis of HCC; - aids in differentiating FNH from HA; - is a promising method in differentiating between the histological subtypes of HA; - combined with diffusion weighted sequences, is the most accurate imaging modality for the diagnosis of colorectal liver metastases, including small lesions below 1 cm.

1. Hope TA, Fowler KJ, Sirlin CB, et al. Hepatobiliary agents and their role in LI-RADS. Abdom Imaging [Internet]. 2015 Mar 7 2. Doo KW, Lee CH, Choi JW, et al. “Pseudo Washout” Sign in High-Flow Hepatic Hemangioma on Gadoxetic Acid Contrast-Enhanced MRI Mimicking Hypervascular Tumor. Am J Roentgenol [Internet]. 2009 Dec 23 3. Kogita S, Imai Y, Okada M, Kim T, et al. Gd-EOB-DTPA-enhanced magnetic resonance images of hepatocellular carcinoma: correlation with histological grading and portal blood flow. Eur Radiol [Internet]. 2010 Oct 19...