Examining LI-RADS recommendations: should observation size only be measured on non-arterial phases?

How to Use LI-RADS to Report Liver CT and MRI Observations

Primary liver cancer is the fourth leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) comprising the vast majority of primary liver malignancies. Imaging plays a central role in HCC diagnosis and management. As a result, the content and structure of radiology reports are of utmost importance in guiding clinical management. The Liver Imaging Reporting and Data System (LI-RADS) provides guidance for standardized reporting of liver observations in patients who are at risk for HCC. LI-RADS standardized reporting intends to inform patient treatment and facilitate multidisciplinary communication and decisions, taking into consideration individual clinical factors. Depending on the context, observations may be reported individually, in aggregate, or as a combination of both. LI-RADS provides two templates for reporting liver observations: in a single continuous paragraph or in a structured format with keywords and imaging findings. The authors clarify terminology that is pertinent to reporting, highlight the benefits of structured reports, discuss the applicability of LI-RADS for liver CT and MRI, review the elements of a standardized LI-RADS report, provide guidance on the description of LI-RADS observations exemplified with two case-based reporting templates, illustrate relevant imaging findings and components to be included when reporting specific clinical scenarios, and discuss future directions. An invited commentary by Yano is available online. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

LI-RADS v2018 major criteria: Do hepatocellular carcinomas in non-alcoholic steatohepatitis differ from those in virus-induced chronic liver disease on MRI?

PURPOSE

LI-RADS v2018 diagnostic system is used to diagnose hepatocellular carcinoma (HCC) in at risk patients. However, its applicability to HCC in non-alcoholic steatohepatitis (NASH) has not been specifically studied. The purpose of this study was to assess the applicability of LI-RADS v2018 diagnostic system for HCC in patients with NASH.

MATERIALS AND METHODS

The MRI examinations of 41 patients with HCC and NASH (NASH group) were reviewed and compared to those obtained in 41 patients with HCC and virus-induced chronic liver disease (Virus group). MRI examinations of the two groups were compared for imaging presentation, LI-RADS major criteria and LI-RADS categorization. Qualitative variables were compared using Fisher exact test and quantitative variables using Mann-Whitney U test Interreader agreement was assessed using kappa statistic.

RESULTS

No significant differences in qualitative and quantitative variables were observed between the two groups. Most common findings in the two groups were hyperenhancement during the arterial phase and visibility on T2-weighted images (93 % vs. 98 %, P = 0.616 and 85 % vs. 88 %, P = 1.000 for NASH group and Virus group, respectively). No differences in prevalence between the two groups were found for any major LI-RADS v2018 criterion. Interreader agreement for LI-RADS categorization was strong for the NASH group (kappa = 0.802) and moderate for the virus group (kappa = 0.720). No differences were found between the two groups for LI-RADS categories (P =  0.303).

CONCLUSIONS

The LI-RADS v2018 diagnostic algorithm can be applied in patients with NASH.