Sella

Due to the extremely intense metabolic activity of the brain, most PET reading software programs will require the reader to manually decrease image intensity to permit adequate evaluation of the brain for potential lesions.  

Sella pathology is also best visualized on these “turned down” black and white axial images.

The normal sella typically demonstrates little or no FDG uptake.

• Very mild metabolic activity, without an obvious corresponding CT abnormality, is frequently seen as a normal variant. 
• Intense sella uptake, without a corresponding soft tissue density on the co-registered CT images, often represents a pituitary microadenoma.
• Intense sella uptake, with a corresponding soft tissue density on the co-registered CT images, usually represents a pituitary macroadenoma.

Even though most cases of moderate to intense sella uptake do not represent malignancy, MRI correlation is still recommended. In such cases, we generally report:

 “Although this uptake can be physiologic or may represent a benign pituitary lesion, MRI correlation is recommended in this case.”