title: Normal conus medullaris FDG uptake in children.
abstract: BACKGROUND
  The biodistribution of 18F-FDG has been well described in both adults and children. Many findings are limited to children and warrant understanding prior to interpretation.
  
  
  OBJECTIVE
  To determine the normal level of conus medullaris uptake, not previously reported in the literature to date, in a series of consecutive FDG PET/CT scans performed in children.
  
  
  METHODS
  With IRB approval, we retrospectively reviewed 100 consecutive whole-body pediatric 18F-FDG PET/CT examinations obtained for various clinical indications. Scans that showed visible uptake of FDG at the conus were objectively evaluated, and standardized uptake value (SUV) was determined. Maximum SUV of the conus was compared to background, normal liver and lung, and ratios were recorded. Pathology in the conus was excluded.
  
  
  RESULTS
  The scans of 100 patients ages 5 months to 24 years (mean 11.7 years) were reviewed. Three patients were excluded. Seventy percent showed uptake at the conus medullaris. SUVs ranged from 1.33 to 4.2 (mean 2.14).
  
  
  CONCLUSIONS
  Low-level 18F-FDG uptake is common in the conus medullaris, represents normal distribution in children and should not be interpreted as metastatic disease to the CNS.
authors: Department of Radiology, Emory University and Children's Healthcare of Atlanta, Decatur, GA 30322, USA. adina.alazraki@choa.org
authors: Adina L
authors: AL
authors: Alazraki
authors: Stephen F
authors: SF
authors: Simoneaux
authors: J Bradley
authors: JB
authors: Wyly
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