Brain

As the brain fully relies on glucose metabolism, it demonstrates rather diffuse intense uptake of FDG. In fact, its metabolic activity is so intense, that most PET reading software programs will require the reader to manually decrease its intensity to evaluate the brain for potential lesions.

Familiarity with the normal symmetric uptake of FDG in the brain will help the reader identify primary brain tumors and metastatic lesions.

Areas of normal relative increased uptake include the grey matter, basal ganglia, frontal eye fields, posterior cingulate gyrus and visual cortex. Symmetry of uptake should be preserved.

As most cases begin at the skull base, careful attention must always be paid to the sella.

[Dementia imaging, also performed with FDG, is beyond the scope of this course].