Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The second article of this two-part review discusses basic concepts of diagnosis and staging, reviews the diagnostic performance of CT and MR imaging with extracellular contrast agents and of MR imaging with hepatobiliary contrast agents, and examines in depth the major and ancillary imaging features used in the diagnosis and characterization of HCC.

Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The first article of this two-part review discusses key concepts of HCC development, growth, and spread, emphasizing those features with imaging correlates and hence most relevant to radiologists; state-of-the-art CT and MR imaging technique with extracellular and hepatobiliary contrast agents; and the imaging appearance of precursor nodules that eventually may transform into overt HCC.

As the utility of liver-specific magnetic resonance imaging (MRI) increases, it is pertinent to optimize and expand protocols to improve accuracy and foster evolution of techniques; in turn, positive impacts should be seen in patient management. This article reports on the latest expert thinking and current evidence in the field of liver-specific MRI, as discussed at the 6(th) International Forum for Liver MRI, which was held in Vancouver, Canada in September 2012. Topics discussed at this forum described the use of gadoxetic acid-enhanced MRI for the assessment of liver function at the segmental level; to increase accuracy in the diagnosis of liver metastases; to overcome current challenges in patients with cirrhosis, including management of arterial hypo-/isovascular, hepatobiliary phase hypointense nodules; and the data which would be required in order to recommend the use of this modality in hepatocellular carcinoma management guidelines. Growing evidence suggests that gadoxetic acid-enhanced MRI can help to improve the management of patients with a number of different liver disorders; however, more data are needed in some areas, and there may be a case for developing an interpretation guideline for gadoxetic acid-enhanced MRI findings to aid standardization.

Level of evidence

5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2018;47:1169-1171.

Objectives

Liver-specific MRI is a fast-growing field, with technological and protocol advancements providing more robust imaging and allowing a greater depth of information per examination. This article reports the evidence for, and expert thinking on, current challenges in liver-specific MRI, as discussed at the 7th International Forum for Liver MRI, which was held in Shanghai, China, in October 2013.

Methods

Topics discussed included the role of gadoxetic acid-enhanced MRI in the differentiation of focal nodular hyperplasia from hepatocellular adenoma and small hepatocellular carcinoma (HCC) from small intrahepatic cholangiocarcinoma (in patients with chronic liver disease), the differentiation of low-grade dysplastic nodule (DN) from pre-malignant high-grade DN and early HCC, and treatment planning and assessment of treatment response for patients with HCC and colorectal liver metastasis. Optimization of the gadoxetic acid-enhanced MRI protocol to gain robust arterial and hepatobiliary phase images was also discussed.

Results and conclusions

Gadoxetic acid-enhanced MRI demonstrates added value for the detection and characterization of focal liver lesions and shows promise in a number of new indications, including regional liver functional assessment and patient monitoring after therapy; however, more data are needed in some areas, and further developments are needed to translate cutting-edge techniques into clinical practice.

Key points

Liver-specific MRI is a fast-growing field, with many technological and protocol advancements. Gadoxetic acid-enhanced MRI demonstrates value for detecting and characterizing focal liver lesions. Gadoxetic acid-enhanced MRI shows promise in regional functional assessment and patient monitoring. Further developments are needed to translate cutting-edge techniques into clinical practice.

Objectives

The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid-enhanced imaging.

Methods

As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid-enhanced MRI in primary liver cancer and metastatic liver disease.

Results and conclusions

Gadoxetic acid-enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid-enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid-enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers.

Key points

• Gadoxetic acid-enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy. • Gadoxetic acid-enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies. • Abbreviated protocols for gadoxetic acid-enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid-enhanced MRI for the assessment of liver and biliary function is under active investigation.