Liver Imaging Reporting and Data System (LI-RADS) Version 2018: Imaging of Hepatocellular Carcinoma in At-Risk Patients

Abstract

The Liver Imaging Reporting and Data System (LI-RADS) is composed of four individual algorithms intended to standardize the lexicon, as well as reporting and care, in patients with or at risk for hepatocellular carcinoma in the context of surveillance with US; diagnosis with CT, MRI, or contrast material-enhanced US; and assessment of treatment response with CT or MRI. This report provides a broad overview of LI-RADS, including its historic development, relationship to other imaging guidelines, composition, aims, and future directions. In addition, readers will understand the motivation for and key components of the 2018 update.

Figure 1a:

Diagram shows changes introduced in Liver Imaging Reporting and Data System (LI-RADS)version 2018. (a) Changes in categorization. Observations 10–19 mm with arterial phase hyperenhancement (APHE) and nonperipheral “washout” are categorized as LR-5 (definite hepatocellular carcinoma), regardless of appearance on antecedent surveillance US images. Qualifiers “-us” and “-g” have been removed. (b) Change in threshold growth definition. Only 50% size increase in 6 months or less qualifies as threshold growth; all other size increases qualify as subthreshold growth.

Figure 1b:

Diagram shows changes introduced in Liver Imaging Reporting and Data System (LI-RADS)version 2018. (a) Changes in categorization. Observations 10–19 mm with arterial phase hyperenhancement (APHE) and nonperipheral “washout” are categorized as LR-5 (definite hepatocellular carcinoma), regardless of appearance on antecedent surveillance US images. Qualifiers “-us” and “-g” have been removed. (b) Change in threshold growth definition. Only 50% size increase in 6 months or less qualifies as threshold growth; all other size increases qualify as subthreshold growth.

Figure 2:

Chart summarizes Liver Imaging Reporting and Data System (LI-RADS) algorithms and target populations for surveillance, diagnosis, staging, and treatment response. AASLD = American Association for the Study of Liver Diseases, CEUS = contrast-enhanced US, HBV = hepatitis B virus, HCC = hepatocellular carcinoma.

Figure 3:

Summary of US Liver Imaging Reporting and Data System categories and visualization scores.

Figure 4:

Chart summarizes Liver Imaging Reporting and Data System version 2018 technical requirements for CT and MRI. IP = in phase, OP = opposed phase, 3D = three dimensional.

Figure 5:

Summary of CT and MRI diagnostic Liver Imaging Reporting and Data System (LI-RADS) categories. APHE = arterial phase hyperenhancement, HBP = hepatobiliary phase, HCC = hepatocellular carcinoma, TIV = tumor in vein, TP = transitional phase.

Figure 6:

Summary of CT and MRI diagnostic Liver Imaging Reporting and Data System major features. APHE = arterial phase hyperenhancement, CEUS = contrast-enhanced US, DWI = diffusion-weighted imaging, ECA = extracellular contrast agent.

Figure 7:

Summary of CT and MRI LR-M (probably or definitely malignant, not hepatocellular carcinoma specific) features. ADC = apparent diffusion coefficient, APHE = arterial phase hyperenhancement, DWI = diffusion-weighted imaging, HBP = hepatobiliary phase, TP = transitional phase.

Figure 8a:

Summary of contrast-enhanced US Liver Imaging Reporting and Data System (a) major and (b) LR-M (probably or definitely malignant, not hepatocellular carcinoma specific) features. APHE = arterial phase hyperenhancement, CEUS = contrast-enhanced US,

Figure 8b:

Summary of contrast-enhanced US Liver Imaging Reporting and Data System (a) major and (b) LR-M (probably or definitely malignant, not hepatocellular carcinoma specific) features. APHE = arterial phase hyperenhancement, CEUS = contrast-enhanced US,

Figure 9:

Summary of CT and MRI treatment response Liver Imaging Reporting and Data System imaging features. APHE = arterial phase hyperenhancement T1-W = T1 weighted.

Figure 10:

Summary of management recommendations for CT and MRI diagnostic and treatment response Liver Imaging Reporting and Data System categories.

Figure 11:

Chart summarizes indicators for biopsy considerations. CEA = carcinoembryonic antigen, HCC = hepatocellular carcinoma, LI-RADS = Liver Imaging Reporting and Data System.