Focal liver lesions detection and characterization: The advantages of gadoxetic acid-enhanced liver MRI

Abstract

Since its clinical introduction, several studies in literature have investigated gadolinium ethoxybenzhyl diethylenetriaminepentaacetic acid or gadoxetic acid (Gd-EOB-DTPA) properties. Following contrast injection, it provides dynamic vascular phases (arterial, portal and equilibrium phases) and hepatobiliary phase, the latter due to its uptake by functional hepatocytes. The main advantages of Gd-EOB-DTPA of focal liver lesion detection and characterization are discussed in this paper. Namely, we focus on the possibility of distinguishing focal nodular hyperplasia (FNH) from hepatic adenoma (HA), the identification of early hepatocellular carcinoma (HCC) and the pre-operative assessment of metastasis in liver parenchyma. Regarding the differentiation between FNH and HA, adenoma typically appears hypointense in hepatobiliary phase, whereas FNH is isointense or hyperintense to the surrounding hepatic parenchyma. As for the identification of early HCCs, many papers recently published in literature have emphasized the contribution of hepatobiliary phase in the characterization of nodules without a typical hallmark of HCC. Atypical nodules (no hypervascularizaton observed on arterial phase and/or no hypovascular appearance on portal phase) with low signal intensity in the hepatobiliary phase, have a high probability of malignancy. Finally, regarding the evaluation of focal hepatic metastases, magnetic resonance pre-operative assessment using gadoxetic acid allows for more accurate diagnosis.

Keywords: Magnetic resonance imaging, Liver, Image enhancement, Gadolinium diethylenetriaminepentaacetic acid, Carcinoma, Hepatocellular

Core tip: This study highlights the added value of gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) in the detection and characterization of focal liver lesions. Three main topics are summarized: the role of gadoxetic acid in the evaluation of solid benign hepatic lesions, represented by hepatocellular adenoma and focal nodular hyperplasia; the diagnostic capability of hepatobiliary phase of gadoxetic acid-enhanced liver magnetic resonance imaging in the early identification of small hepatocellular carcinoma; the high diagnostic accuracy powered by gadoxetic enhanced-liver MRI in the detection of hepatic metastasis.