Salivary Glands

The parotid, submandibular and sublingual glands usually demonstrate only mild metabolic activity.  Not infrequently, however, they can be even intensely avid.

As long as FDG uptake in these glands is bilateral, diffuse and not accompanied by a soft tissue lesion, even intensely avid salivary glands are considered normal.

Focal, unilateral, or asymmetric uptake (or uptake associated with a soft tissue abnormality) should always at least raise a concern for pathology — either malignancy or infection.