Pictorial review of the LI-RADS radiation-based treatment response algorithm v2024

Hepatocellular carcinoma can be treated with liver transplantation, surgical resection, or locoregional therapy. Locoregional therapy encompasses a broad range of therapeutic options, including non-radiation- and radiation-based options. The assessment of treatment response following radiation-based options is often challenging as imaging findings following these therapies evolve over time. In response to this challenge, and with advancements in knowledge of the expected imaging findings following locoregional therapy, the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm was updated in 2024 by the American College of Radiology Treatment Response Working Group. The 2024 version was separated into two distinct algorithms, reflecting the differences in the expected imaging findings following non-radiation- and radiation-based options. This article presents a pictorial review of the expected and unexpected imaging appearance of hepatocellular carcinoma following treatment with radiation-based locoregional therapy options using the LI-RADS treatment response algorithm v2024.