Hepatocellular carcinoma (HCC) is the sixth most common malignant tumor worldwide, with a significantly increased incidence among patients with liver diseases. Even if HCC can be treated by surgical resection and ablation, the 5-year recurrence rate is as high as 50-70%. The Liver Imaging Reporting and Data System (LI-RADS), released by the American College of Radiology (ACR), is a classification management system specifically designed to evaluate liver lesions in high-risk HCC patients. Since its release in 2011, the CT/MRI LI-RADS has been updated to the 2018 version. Subsequently, the CEUS LI-RADS was introduced in 2016 and updated in 2017. The CEUS LI-RADS standard has relatively high specificity but lacks sensitivity. The ESCULAP (Erlanger Synopsis of Contrast-enhanced Ultrasound for Liver lesion Assessment in Patients at Risk) standard proposed by Schellhaas et al. in Germany has high sensitivity in diagnosing HCC in patients with liver diseases . However, there is currently a lack of research on the diagnostic efficacy of these two standards for the re-discovery of liver space-occupying lesions in patients with a history of HCC. This study aims to compare the diagnostic efficacy of the two standards for recurrent HCC in patients with a history of HCC.