title: Bone marrow fat content is correlated with hepatic fat content in paediatric non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  To investigate the relationship between bone marrow fat content and hepatic fat content in children with known or suspected non-alcoholic fatty liver disease (NAFLD).
  
  
  METHODS
  This was an institutional review board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant, cross-sectional, prospective analysis of data collected between October 2010 to March 2013 in 125 children with known or suspected NAFLD. Written informed consent was obtained for same-day research magnetic resonance imaging (MRI) of the lumbar spine, liver, and abdominal adiposity. Lumbar spine bone marrow proton density fat fraction (PDFF) and hepatic PDFF were estimated using complex-based MRI (C-MRI) techniques and magnitude-based MRI (M-MRI), respectively. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT) were quantified using high-resolution MRI. All images were acquired by two MRI technologists. Hepatic M-MRI images were analysed by an image analyst; all other images were analysed by a single investigator. The relationship between lumbar spine bone marrow PDFF and hepatic PDFF was assessed with and without adjusting for the presence of covariates using correlation and regression analysis.
  
  
  RESULTS
  Lumbar spine bone marrow PDFF was positively associated with hepatic PDFF in children with known or suspected NAFLD prior to adjusting for covariates (r=0.33, p=0.0002). Lumbar spine bone marrow PDFF was positively associated with hepatic PDFF in children with known or suspected NAFLD (r=0.24, p=0.0079) after adjusting for age, sex, body mass index z-score, VAT, and SCAT in a multivariable regression analysis.
  
  
  CONCLUSIONS
  Bone marrow fat content is positively associated with hepatic fat content in children with known or suspected NAFLD. Further research is needed to confirm these results and understand their clinical and biological implications.
authors.affiliation: Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA.
authors.forename: N Y
authors.initials: NY
authors.lastname: Yu
authors.affiliation: Computational and Applied Statistics Laboratory, San Diego Supercomputer Center, University of California, San Diego, La Jolla, CA, USA.
authors.forename: T
authors.initials: T
authors.lastname: Wolfson
authors.affiliation: Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Middleton
authors.affiliation: Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Hamilton
authors.affiliation: Computational and Applied Statistics Laboratory, San Diego Supercomputer Center, University of California, San Diego, La Jolla, CA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gamst
authors.affiliation: Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Diego School of Medicine, San Diego, CA, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Angeles
authors.affiliation: Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA; Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Diego School of Medicine, San Diego, CA, USA; Department of Gastroenterology, Rady Children's Hospital San Diego, San Diego, CA, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Schwimmer
authors.affiliation: Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA. Electronic address: csirlin@ucsd.edu.
authors.forename: C B
authors.initials: CB
authors.lastname: Sirlin
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D001853:Bone Marrow / Q000473:pathology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008099:Liver / Q000473:pathology*; D008297:Male; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult