Gadoxetic acid-enhanced MRI in hepatocellular carcinoma: a comprehensive review of diagnostic, surveillance, and treatment response prediction and assessment.

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) has become a pivotal imaging modality in hepatocellular carcinoma (HCC) management, offering unique advantages owing to its hepatocyte-specific contrast properties. Its technical foundation includes optimized dynamic phase imaging and hepatobiliary phase (HBP) acquisition, which together provide functional information unattainable with conventional extracellular contrast agents. This modality enhances sensitivity in detecting HCC and enables superior characterization of focal liver lesions based on hepatocyte-specific uptake patterns. In high-risk patients with chronic liver disease, gadoxetic acid-enhanced MRI facilitates the early detection of small and early-stage HCCs, enabling timely intervention and potentially improving clinical outcomes. Beyond diagnosis, gadoxetic acid-enhanced MRI aids in predicting treatment response by evaluating tumor biological characteristics. Key imaging biomarkers include: hyperintense or heterogeneous HCC on HBP, suggesting tumor immune microenvironment; peritumoral hypointensity on HBP, suggesting microvascular invasion; and clear hypointensity on HBP with several other findings, indicating vessels encapsulating tumor clusters, characteristic of the macrotrabecular-massive HCC subtype. These biomarkers support a comprehensive evaluation of histological differentiation and biological aggressiveness. Furthermore, this modality demonstrates superior accuracy in assessing local therapy effectiveness and monitoring systemic treatment responses compared to conventional imaging. Major international hepatology societies have incorporated gadoxetic acid-enhanced MRI into their HCC diagnostic algorithms, albeit with regional differences in emphasis. Eastern guidelines (e.g., from the Japan Society of Hepatology and the Asian Pacific Association for the Study of the Liver) prioritize sensitivity, whereas Western guidelines (e.g., from the European Association for the Study of the Liver and the Liver Imaging Reporting and Data System) emphasize specificity. Despite certain limitations, including potential suboptimal arterial phase visualization, challenges in interpreting the transitional phase, higher cost, and longer examination times, gadoxetic acid-enhanced MRI remains an indispensable tool in precision oncology, enabling personalized treatment strategies and supporting optimal patient outcomes through comprehensive HCC characterization and accurate treatment monitoring.