Abstract: Objective The aim of this study was to investigate the diagnostic efficacy of contrast-enhanced ultrasound (CEUS) time-intensity curve (TIC) parameters and liver imaging reporting and data system (LI-RADS) classification in differentiating diagnosis of liver space-occupying lesions (SOL). Methods 82 patients with liver SOL were encountered in our hospital between January 2020 and December 2024, and the diagnosis was proven by liver histo-pathological examination. All patients underwent CEUS to record TIC parameters, including peak intensity, time to peak, rise time, mean transit time and blood flow perfusion index. Intrahepatic lesions were classified according to LI-RADS criteria, with LR-4a as the cut-off value, e.g., LR-1 to LR-4a were classified as benign, and LR-4b to LR-5 were defined as malignant lesions. Results Of the 82 patients with liver SOL, liver histo-pathological examination found malignant lesions in 43 cases (52.4%), and benign ones in 39 cases (47.6%); peak intensity and mean transit time in malignant lesions were(126.2±15.7)% and (126.8±26.0)s, both significantly lower or faster than [(140.5±18.4)% and (246.6±42.6)s, respectively, P<0.05], while time to peak, rise time and blood flow perfusion index were (21.4±3.9)s, (34.4±6.3)s and (85.2±14.6), all much slower or greater than [(17.3±3.2)s, (30.3±5.6)s and (50.4±7.8), respectively, P<0.05] in benign lesions; false negative false positive rates by LI-RADS diagnosis was 13.9% and 10.2%; the sensitivity and specificity by CEUS quantitative parameters were 95.3%(41/43) and 84.6%(33/39), and they were 86.0%(37/43)and 89.7%(35/39) by LI-RADS. Conclusion Both the quantitative parameters of CEUS TIC and the LI-RADS classification demonstrate satisfactory diagnostic performance in distinguishing benign from malignant liver SOL, which warrants further clinical investigation.

Key words: Hepatoma, Focal nodular hyperplasia, Contrast enhanced ultrasound, Time-intensity curve, Liver imaging reporting and data system, Diagnosis