Normative Values for Liver Ultrasound Shear Wave Elastography, Shear Wave Dispersion and Attenuation Imaging in a Pediatric Cohort during Free Breathing

Author(s): Sarovic Darko*, Cetinic Ivan, Ekvall Nils, Lagerstrand Kerstin, de Lange Charlotte, Hebelka, Hanna

Ultrasound markers for liver characterization show promise to improve diagnostics but normative data in children are scarce. The purpose was to report normative values of liver ultrasound Shear Wave Elastography (SWE), Shear Wave Dispersion (SWD) and Attenuation Imaging (ATI), reflecting hepatic elasticity, viscosity, and steatosis respectively, in children. Seventy-one children, without liver disease, referred for ultrasound-guided kidney biopsy were consecutively enrolled. Individuals with BMI>25 were excluded. SWE, SWD and ATI were measured during free breathing, fasting >4h and under general anesthesia (n=60) and/ or while awake (n=42) and correlation to anesthesia, sex, age, and BMI were investigated. The mean age and BMI were 10.8 years (range 2.3- 17.8), and 18.4 (range 12.8-25.0) respectively, 49% were boys. Averages and standard deviations were SWE 4.9±1.1kPa, SWD 11.9±1.5m/s/kHz, and ATI 0.56±0.09dB/cm/MHz. There was no difference between sexes (p>0.15), effect of anesthesia (p>0.32), or between age groups (0-5, 5-12, 12-18 years; p>0.15). A moderate correlation was found between BMI and SWD (R=-0.43, p=0.006), while no other significant correlations were identified (R<0.31, p>0.08). Normative pediatric values for SWE, SWD and ATI, during both free breathing and fasting, are reported. Other than a weak negative correlation between BMI and SWD, the lack of significant associations implies that these normative values can be applied across ages and sexes.