title: Pediatric obesity phenotyping by magnetic resonance methods.
abstract: OBJECTIVE
  Accurate measurement of adiposity in obese children is required for characterizing the condition's phenotype, severity, and treatment effects in vivo. Non-invasive and safe, magnetic resonance imaging and spectroscopy provide an important new approach for characterizing key aspects of pediatric obesity. This review focuses on recent advances in non-invasive magnetic resonance imaging and spectroscopy for quantifying total body and regional adiposity, mapping adipose tissue distribution, and evaluating selected metabolic disturbances in children. The aim is to provide an investigator-focused overview of magnetic resonance methods for use in the study of pediatric body composition and metabolism.
  
  
  RESULTS
  Whole body axial images can be rapidly acquired on most clinical magnetic resonance imaging scanners. The images can then be semi-automatically segmented into subcutaneous, visceral, and intramuscular adipose tissue. Specific pediatric studies of errors related to slice gap and number are available. The acquisition of scans in healthy and premature infants is now feasible with recent technological advances. Spectroscopic, Dixon, and other approaches can be used to quantify the lipid content of liver, skeletal muscle, and other organs. Protocol selection is based on factors such as subject age and cost. Particular attention should be directed towards identification of landmarks in growth studies. Recent advances promise to reduce the requirement of subjects to remain motionless for relatively long periods.
  
  
  CONCLUSIONS
  Magnetic resonance imaging and spectroscopy are safe, practical, and widely available methods for phenotyping adiposity in children that open new opportunities for metabolism and nutritional research.
authors.affiliation: New York Obesity Research Center, St. Luke's-Roosevelt Hospital, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY 10025, USA. ws2003@columbia.edu
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
authors.forename: Mark
authors.initials: M
authors.lastname: Punyanitya
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology; D050154:Adiposity; D000293:Adolescent; D001823:Body Composition / Q000502:physiology*; D001824:Body Constitution / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology*; D010641:Phenotype; D013057:Spectrum Analysis