title: Pediatric brown adipose tissue: detection, epidemiology, and differences from adults.
abstract: OBJECTIVE
  To evaluate the prevalence and factors affecting the detection of active brown adipose tissue (BAT) in children and adolescents using (18)F-fluorodeoxyglucose positron emission tomography.
  
  
  METHODS
  A total of 385 positron emission tomography scans performed for various oncologic indications in 172 patients aged 5-21 years were reviewed. BAT activity was detected by visual inspection as present or absent in the neck, thorax, and abdomen based on its well-characterized and typical appearance and then quantified by comparing the (18)F-fluorodeoxyglucose activity in the cervical-supraclavicular depots with that measured in the liver. Clinical indices were recorded.
  
  
  RESULTS
  The BAT detection rate was not significantly different between boys and girls (43.3% vs 45.3%). BAT activity was found most often in the cervical-supraclavicular depots. The highest percentage of patients with detectable BAT and the highest BAT/liver activity were in the 13- to 14.99-year age group in both males and females (P = .005). Body mass index percentile correlated inversely with BAT activity (P = .012). BAT activity did not correlate with outdoor temperature or clinical diagnosis.
  
  
  CONCLUSIONS
  Under typical clinical imaging conditions, BAT is detected more frequently in children than in adults. BAT activity increases from childhood into adolescence, when it is detected in almost half of patients, and it correlates inversely with obesity, suggesting that BAT may play a prominent role in pediatric metabolism.
authors.affiliation: Department of Radiology, Children's Hospital Boston, Boston, MA 02466, USA. laura.drubach@childrens.harvard.edu
authors.forename: Laura A
authors.initials: LA
authors.lastname: Drubach
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Palmer
authors.forename: Leonard P
authors.initials: LP
authors.lastname: Connolly
authors.forename: Amanda
authors.initials: A
authors.lastname: Baker
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Cypess
mesh_terms: D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007223:Infant; D008297:Male; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18