FDG-PET for Measurement of Brain Metabolism

This blog describes the technique of FDG-PET in measuring brain metabolism in patients in the inter-ictal continuum..


  • PET is co-registered to T1 MRI images.
  • 10% color gradation (blue [hypo], green, yellow, red [hyper])
  • cerebellum set to yellow
  • measure maximum standardized uptake value (SUVmax)
    • Regions:
      • mesial temporal
      • basal ganglia
      • thalamic
      • neo-cortex (frontal, temporal, parietal, occipital)
    • SUVmax = voxel of highest SUV for a specified region
    • SUV = ratio of radioactivity per voxel expressed as concentration (megaBeckquerel/Kg) divided by injected dose of radiation/Kg body mass
  • Options for reference? (reference SUVmax or rSUVmax)
    • internal control:  20% relative difference in SUVmax
    • if focal:  use contralateral homologous region
    • cerebellum:  compare to total cerebellar SUVmax
    • if bilateral:  50% increase of SUVmax relative to cerebellum
  • classify hyper- / hypometabolism as
    • focal (single region)
    • regional (extends to subcortical / adjacent)
    • or diffuse (bilateral)











Renard, D. et al. “Teaching Neuroimages: FDG-PET In Progressive Supranuclear Palsy”. Neurology74.14 (2010): e60-e60.

Struck, Aaron F. et al. “Metabolic Correlates Of The Ictal-Interictal Continuum: FDG-PET During Continuous EEG”. Neurocritical Care 24.3 (2016): 324-331.

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