Measuring Fatty Liver With Ultrasound and MRS in Children With Overweight or Obesity

Obesity is associated with a variety of comorbidities, amongst which non-alcoholic fatty liver disease (NAFLD). A recent meta-analysis has shown that the prevalence of NAFLD in obese pediatric populations is around 35%, compared to approximately 8% in general pediatric populations, making it a very important health threat in these populations. The golden standard for diagnosis of NAFLD is liver biopsy. However, since liver biopsy is associated with a certain risk of morbidity and mortality, this method is inappropriate for screening large populations at-risk for developing NAFLD. Magnetic resonance spectroscopy has demonstrated excellent correlation with liver biopsy and the is the most accuratete non-invasive method to measure liver fat content in children. However, MRS is expensive and not available in all centres. A novel ultrasonographic measurement to quantitatively assess liver steatosis is the hepatorenal index (HRI). Previous studies have shown high sensitivity and specificity of the HRI, as compared to MRS and liver biopsy. However, this measurement has never been validated in children. In this study, the HRI will be compared to MRS in children with obesity, to validate the HRI and to determine cut-off points.