Abstract: Objective The purpose of this study was to investigate the feasibility of non-invasive evaluation by contrast-enhanced ultrasound (CEUS) in patients with radiation-induced liver injury (RILI). Methods A total of 42 patients with abdominal malignant tumors received radiotherapy in our hospital between June 2016 and January 2020. Color Doppler CEUS was conducted for measurement of the time to peak (TTP), the gradient (GRAD) and the area under the curve (AUC) in the livers. Results The TTP in the 42 patients at baseline, two, three and four weeks after radiotherapy were (14.2±2.4)s, (18.5±3.0)s, (23.2±3.2)s and (30.1±4.0)s, respectively, with significant differences between them (P<0.05); the GRAD were (2.1±0.2), (1.6±0.1), (1.0±0.1) and (0.7±0.1), significantly different (P<0.05), while the AUC were (3220.8±120.4), (2910.9±102.5), (2785.5±101.2) and (3248.6±89.5), lacking regularity; at week three and four, serum ALT levels were (45.5±9.8)U/L and (60.8±10.5)U/L, serum AST levels were (44.8±10.2)U/L and (61.2±12.5)U/L, serum GGT levels were (74.3±7.5)U/L and (86.3±8.0)U/L, and serum AKP levels were (96.8±36.0)U/L and (105.8±40.2)U/L, respectively, all significantly higher than at baseline or at week two after radiotherapy(P<0.05), meeting the diagnosis of RILI. Conclusion The measurementof TTP, GRAD and AUC by CEUS scan could be used as an important quantitative index for early diagnosis of RILI in patients with malignant tumors undergoing radiotherapy, which might accurately and objectively evaluate the changes of intrahepatic microcirculation in acute RILI.

Key words: Radiation-induced liver injury, Contrast-enhanced ultrasonography, Diagnosis