The document summarizes the key changes in the 2017 version of LI-RADS (Liver Imaging Reporting and Data System) for CT and MR imaging. The major changes include new categories to better characterize observations for diagnosis and treatment response assessment. For diagnosis, new categories were added for observations that cannot be categorized (LR-NC) and for malignancies other than hepatocellular carcinoma (LR-M). Treatment response criteria were also added. Thresholds for major features like tumor growth were clarified. Ancillary features were designated as optional to upgrade or downgrade categories by one level.