The purpose of this study is to see if the HepaFat-Scan (a special sequence of images done in a MRI) can accurately detect the amount of fat in the liver.

The leading cause of liver disease for both adults and children in the US is nonalcoholic fatty liver disease (NAFLD), an obesity-related liver disease closely associated with the metabolic syndrome. NAFLD increases the risk of liver disease but also increases risk of type II diabetes, cardiovascular disease (CVD) and the metabolic syndrome. Invasive liver biopsy has been considered the best diagnostic tool for confirming NAFLD. This study will establish magnetic resonance imaging (MRI) / magnetic resonance spectroscopy (MRS) as a quantitative noninvasive "virtual biopsy" and benefit the health of children with liver diseases by decreasing risk and improving diagnosis. Specifically, in NAFLD, this fat quantification protocol will be broadly useful in future research studies, including therapies for NAFLD as well as for patient diagnosis and follow-up.

Inclusion Criteria:

• Boys and girls age 7-18 years
• Scheduled for a clinically indicated liver biopsy
• Able to undergo MRI without sedation
• Written informed consent from parent or legal guardian
• Written informed assent from the child when indicated by age

Exclusion Criteria:

• Renal disease with a creatinine > 2 or requiring dialysis
• Metal, braces or other implanted devices not compatible with MRI
• Not willing to try to hold still for an un-sedated MRI
• Pregnancy
• Failure to give consent or assent