LAUSR

Purpose of study Visceral adiposity (VAT) and hepatic fat are critical to later childhood obesity and non-alcoholic liver disease (NAFLD). While magnetic resonance imaging (MRI) can non-invasively and accurately quantify these biometrics, it requires breath-holding (BH) and sedation. As a result, current technology precludes many children. Using non-sedated free-breathing (FB)-MRI, this study’s objectives were to 1) evaluate the accuracy and repeatability of FB-MRI vs BH-MRI, 2) correlate hepatic proton density fat fraction (H-PDFF,%) and VAT volume (cm3/m2), and 3) assess feasibility of this technology in infants. Methods used This study had 3 groups: 1) healthy controls (CON), ages 6–17 years, body mass index (BMI)<85%, 2) NAFLD subjects, ages 6–17 years with suspected NAFLD, BMI>85%, and 3) infants, 28 days – 1 year of age. CON and NAFLD subjects underwent BH- and FB-MRI. Infants underwent FB-MRI. Summary of results 10 CON, 9 NAFLD, and 5 infants completed the study. When FB- and BH-MRIs were compared, the correlation coefficients were r=0.996 and pc=0.994. Mean (±SE) H-PDFF and VAT were higher in the NAFLD vs CON (21.9%±4.3% vs 2.6±0.3% and 876±94 cm3/m2 vs 261±18 cm3/m2 (p<0.001)). H-PDFF was correlated with VAT (r=0.86, p<0.001) (table 1). A H-PDFF threshold of 4.29% separates NAFLD from CON. For each unit increase in VAT-PDFF in the NAFLD group, H-PDFF increased by 2.64 (r2=0.54, p=0.02). In infants, H-PDFF and VAT were 3.2%±0.8% and 160±64 cm3/m2, respectively. Conclusions FB-MRI is a novel tool to quantify body composition and liver disease in children. Research is warranted to determine if infants with increased VAT and hepatic fat are at risk for future NAFLD. Abstract 243 Table 1 Correlation of H-PDFF for CON and NAFLD