White paper of the Society of Abdominal Radiology hepatocellular carcinoma diagnosis disease-focused panel on LI-RADS v2018 for CT and MRI

Abstract

The Liver Imaging and Reporting Data System (LI-RADS) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver imaging with the overarching goal of improving communication, clinical care, education, and research relating to patients at risk for or diagnosed with hepatocellular carcinoma (HCC). In 2018, the American Association for the Study of Liver Diseases (AASLD) integrated LI-RADS into its clinical practice guidance for the imaging-based diagnosis of HCC. The harmonization between the AASLD and LI-RADS diagnostic imaging criteria required minor modifications to the recently released LI-RADS v2017 guidelines, necessitating a LI-RADS v2018 update. This article provides an overview of the key changes included in LI-RADS v2018 as well as a look at the LI-RADS v2018 diagnostic algorithm and criteria, technical recommendations, and management suggestions. Substantive changes in LI-RADS v2018 are the removal of the requirement for visibility on antecedent surveillance ultrasound for LI-RADS 5 (LR-5) categorization of 10-19 mm observations with nonrim arterial phase hyper-enhancement and nonperipheral "washout", and adoption of the Organ Procurement and Transplantation Network definition of threshold growth (≥ 50% size increase of a mass in ≤ 6 months). Nomenclatural changes in LI-RADS v2018 are the removal of -us and -g as LR-5 qualifiers.

Diagnostic performance of LI-RADS version 2018 in differentiating hepatocellular carcinoma from other hepatic malignancies in patients with hepatitis B virus infection

“…In cases of patients with multiple pathologically confirmed lesions, the largest tumor was evaluated for each patient. Before reviewing the MR images, both radiologists were given 3 months of hands-on instruction regarding the details of LI-RADS v2018 [12]. LI-RADS features that involve longitudinal assessment (threshold growth, subthreshold growth, size stability, and size reduction) were not applicable in this study as only one scan was evaluated per patient.…”

“…The liver imaging reporting and data system (LI-RADS) is a comprehensive algorithm which provides tools for standardizing the imaging diagnosis of patients at risk for HCC, and it is now completely concordant with the American Association for the Study of Liver Diseases (AASLD) guidance for the definite diagnosis and management of HCC [10,11]. The latest versions of LI-RADS (LI-RADS v2017 and 2018) [12], in addition to updated criteria for HCC diagnosis, also provide precise imaging criteria for assigning category LR-M (probable or definite malignancy, not specific for HCC). LR-M features are based predominately on the imaging characteristics of ICCAs but have also been reported in cHCC-CCAs [13].…”

Brazilian Society of Hepatology Updated Recommendations for Diagnosis and Treatment of Hepatocellular Carcinoma

“…Due to the heterogeneity of HCC features over hepatocarcinogenesis, the complexity of treatment of these patients, and the possibility of other malignant lesions in cirrhotic patients, a more reproducible and objective system of classification of focal hepatic lesions has become necessary in this group of high-risk patients for HCC. In this context, the LI-RADS ® (Liver Imaging Reporting And Data System) emerged with the aim of standardizing the imaging technique and terminology used to describe focal liver lesions, as well as to assist in the interpretation of results and in the standardization of reports (79)(80)(81) .…”

“…The following diagnostic categories are used in the CT/MRI LI-RADS ® (79,80) : LR-NC: not categorizable due to image omission of relevant study phases or image degradation; LR-1: definitely benign; LR-2: probably benign; LR-3: intermediate probability of malignancy; LR-4: probably HCC; LR-5: definitely HCC; LR-M: probably or definitely malignant but not HCC specific; and LR-TIV: definite tumor in vein.…”

MRI characterization of focal liver lesions in non-cirrhotic patients: assessment of added value of gadoxetic acid-enhanced hepatobiliary phase imaging

“…Sixtyeight patients (54.4%) had imaging follow-up at least 6 months after the initial MRI (median 43 months [range 6-96]) and 3 patients had imaging follow-up less than 6 months (median 4 months [range 3-5]). Threshold growth was defined as size increase by minimum 5 mm and more than 50% increase in size in less than 6 months or more than 100% increase in size in 6 months or more [13].…”