Abstract: Objective The purpose of this study was to investigate liver ultrasound attenuation coefficient (AC) and body mass index (BMI) in predicting metabolic dysfunction-associated steatohepatitis (MASH)in obese children. Methods 129 obese children and 67 healthy children were recruited in our hospital between January 2022 and December, and all underwent ultrasonography to detect liver AC, and Fibrotouch to detect controlled attenuation parameter (CAP). MASH was diagnosed by elevation of serum ALT and/or AST levels in children with metabolic dysfunction-associated liver fatty disease (MAFLD). Receiver operating characteristic (ROC) curve was drawn to evaluate predicting efficacy. Results Of the 129 children with MAFLD, MASH was found in 58 cases (45.0%), including mild, moderate and severe liver steatosis in 26 cases, 20 cases and 12 cases, and simple fatty liver (SFL) was found in 71 cases (55.0%); BMI and AC in children with MASH were (30.1±3.4)kg/m² and (0.9±0.2)db/cm/MHz, both significantly higher than [(26.5±2.9)kg/m² and (0.6±0.1)db/cm/MHz, respectively, P<0.05]in those with SFL or [(23.7±1.7)kg/m² and (0.4±0.1)db/cm/MHz, respectively P<0.05]in healthy control; BMI and AC in MASH and severe liver steatosis were (33.9±3.6)kg/m² and (1.3±0.4)db/cm/MHz, both much higher than [(30.4±3.4)kg/m² and (1.0±0.2)db/cm/MHz, respectively, P<0.05]in those with moderate liver steatosis or [(25.1±2.0)kg/m² and (0.6±0.1)db/cm/MHz, respectively, P<0.05] in those with mild liver steatosis; ROC analysis showed that the AUC was 0.940(95% CI:0.898-0.981), with sensitivity of 79.3% and specificity of 98.6%, when AC was combined with BMI in predicting MASH in children with MAFLD. Conclusion Ultrasound-detected AC in combination with BMI could help pediatricians make judgement of MASH in obese children preliminarily, which might provide clues for further managements.

Key words: Metabolic dysfunction-associated fatty liver disease, Ultrasound attenuation imaging, Body mass index, Obesity, Diagnosis, Children