Gadoxetic Acid-Enhanced MRI Compared with Unspecific Extracellular Contrast Media for Differential Diagnosis of Metastasis and Benign Liver Lesions

Introduction

In the staging of a malignant disease, metastatic involvement of the liver has to be ruled out in almost all instances. The demand from liver imaging is accurate detection of metastasis and exact differentiation from frequent benign lesions. For several years, computed tomography (CT) was the method of choice for clinical liver imaging.

Abstract

Extracellular space gadolinium-based contrast media (ECCM) were considered as the standard in contrast-enhanced liver MRI since the early nineties. ECCM increase the accuracy of focal lesion detection and characterization by providing perfusion information with temporal resolution, typically in arterial, portal venous, and equilibrium phases.

With the focus to further increase the accuracy of lesion detection, different liver-specific contrast media were developed and approved. The first generation of this group was not bolus injectable, thereby reducing the potential for focal lesion characterization because of the missing possibility to access the dynamics in lesion perfusion. The recently approved Gd-based contrast medium gadoxetic acid (Primovist†, Bayer Healthcare, Germany) combines the perfusion characteristics of ECCM with a high hepatocyte-specific uptake 10-20 minutes after administration. Gadoxetic acid has proven similar enhancement characteristics in the early perfusion phases compared with ECCM and contrast-enhanced CT. In addition, information about possible hepatocyte-selective uptake in lesions helps to identify lesions of hepatocellular origin and, therefore, offers valuable molecular information for characterization of focal lesions.

For differential diagnosis between metastasis and benign liver lesions, including liver cysts, hemangiomas, and other more uncommon benign liver lesions, gadoxetic acid offers additional useful functional information about hepatocytic uptake, thereby increasing the confidence for lesion characterization, allowing more accurate therapy planning and reducing the need for lesion biopsies. Gadoxetic acid represents the highest standard for non-invasive metastasis identification and reliable differential from typical benign liver lesion.

Keywords

gadoxetic acid, gadolinium, liver neoplasms, magnetic resonance, extracellular contrast media