Multiparametric ultrasound characterizes pediatric cystic fibrosis hepatobiliary involvement

OBJECTIVES: The contemporary European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) framework broadens the definition of cystic fibrosis hepatobiliary involvement (CFHBI), but the biological interpretation of individual multiparametric ultrasound parameters within this framework remains unclear. We evaluated the biological associations of shear wave elastography (SWE), shear wave dispersion (SWD), and attenuation imaging (ATI) with histopathological phenotypes in children with cystic fibrosis (CF). METHODS: In this ambispective cohort study, 119 children with CF underwent hepatobiliary assessment, including SWE, SWD, ATI, Doppler ultrasonography, clinical and laboratory evaluation. Histopathological assessment was performed when clinically indicated. CFHBI was classified according to the ESPGHAN/NASPGHAN framework, with the Debray criteria used as a secondary exploratory comparison. Exploratory phenotype-oriented analyses evaluated ultrasound parameters according to corresponding histopathological phenotypes. RESULTS: Exploratory phenotype-oriented analyses demonstrated significantly higher ATI values in histopathologically defined steatosis (p < 0.001), with good discriminatory performance (AUC 0.813) and an optimal threshold of 0.655 dB/cm/MHz. In contrast, SWE was not associated with histopathologically defined fibrosis (p = 0.151), whereas SWD showed no significant phenotype-specific associations. Secondary exploratory analyses demonstrated significant overall CFHBI discrimination by all three ultrasound parameters, with the highest AUC observed for SWD. The ESPGHAN/NASPGHAN and Debray classifications demonstrated significant disagreement (McNemar p < 0.001), with 22.7% of patients classified as Debray-negative but ESPGHAN/NASPGHAN-positive. CONCLUSIONS: Multiparametric ultrasound should be interpreted within the contemporary ESPGHAN/NASPGHAN CFHBI framework rather than as a single diagnostic tool for hepatobiliary involvement. The distinct biological associations of SWE, ATI, and SWD support a phenotype-oriented interpretation of individual ultrasound parameters, whereas overall CFHBI discrimination should be interpreted as a secondary exploratory finding requiring prospective multicenter validation.