Abstract: Objective The aim of this study was to compare the diagnostic efficacy of contrast-enhanced ultrasound (CEUS) and enhanced CT scan in patients with small hepatocellular carcinoma (sHCC). Methods 104 patients with intrahepatic nodules with diameter of less than 3.0 cm were encountered in our hospital between January 2020 and June 2022, and all underwent CEUS and enhanced CT scan. The gold diagnostic criteria was based on fine needle aspiration biopsies and/or histopathological examination after operation. The 2018 edition Liver Imaging Reporting and Data System (LI-RADS) was applied to classify the hepatic nodules, and the diagnostic efficacy of CEUS and enhanced CT scan was compared by Kappa coefficient. The differences in CEUS quantitative parameters including initial enhancement time, peak time and initial clearance time was compared too. Results The classification of CEUS and enhanced CT scan was consistent in 93 cases (89.4%) in patients with intrahepatic nodules, showing a good consistency (Kappa coefficient=0.749, P<0.05); there were 42 cases with sHCC (including highly differentiated in 29 cases and poorly differentiated in 13 cases) and 62 cases with small benign hepatic nodules among our 104 patients finally confirmed by pathological examination; the Kappa consistency test showed that both the CEUS and enhanced CT scan had good diagnostic efficacy in diagnosing sHCC (P<0.05), and the diagnostic consistencies of CEUS and enhanced CT scan with gold criteria were good when the LR-4/LR-5 was defined as HCC(Kappa=0.861 and Kappa=0.803),suggesting the CEUS was relatively superior to CT scan; the peak time and initial clearance time in patients with highly-differentiated sHCC were(29.4±4.8)s and (62.4±5.7)s, both significantly longer than [(25.0±4.3)s and (51.8±5.2)s, respectively, P<0.05] in those with poorly-differentiated patients. Conclusion Both the CEUS and enhanced CT scan have a good diagnostic efficacy in diagnosing sHCC, and the CEUS might be superior under certain circumstance, which provide more information for tumor classification.

Key words: Hepatoma, Contrast-enhanced ultrasound, Enhanced CT scan, Diagnosis