title: Brown fat distribution in the chest wall of infants-normal appearance, distribution and evolution on CT scans of the chest.
abstract: BACKGROUND
  While reviewing chest CT scans of infants, we repeatedly observed hyperdense enhancing tissue in the chest wall that is not well described in radiology literature.
  
  
  OBJECTIVE
  This study was undertaken to describe the imaging features of this tissue in chest walls of infants.
  
  
  METHODS
  CT scans of the chest conducted on all infants between April 2008 and October 2009 were retrospectively reviewed. CT studies with any deviation from normal radiation or contrast dose or those with chest wall anatomical distortion were excluded.
  
  
  RESULTS
  One hundred eighty-eight infants were scanned, with 202 MDCTs, of which 180 (89.1%) received contrast agent. Fifty-four of 180 (30%) cases revealed focal areas of hyperdensity in various locations. All positive cases ranged between 2 days and 9 months of age. The areas of distribution of hyperdensity had excellent correlation with known areas of brown fat in the chest wall, known from nuclear medicine studies, and hence we concluded these to represent the same.
  
  
  CONCLUSIONS
  Brown fat in the chest wall can be seen as enhancing tissue on contrast CT scans done on infants. This is a normal morphological component with the brown fat converting to normal fat. It is important to recognize it in the chest wall of infants to avoid misinterpretation.
authors.affiliation: Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada. drpriyagupta@yahoo.co.in
authors.forename: Priya
authors.initials: P
authors.lastname: Gupta
authors.forename: Paul S
authors.initials: PS
authors.lastname: Babyn
authors.forename: Amer
authors.initials: A
authors.lastname: Shammas
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Miller
mesh_terms: D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D012189:Retrospective Studies; D035441:Thoracic Wall / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media