Waldeyer's Ring

This ring-like arrangement of lymphoid tissue encircles the pharynx, and includes the palatine tonsils, adenoids, lateral walls of the oropharynx, and the lingual tonsils along the base of the tongue.

Although its metabolic activity is variable, it frequently demonstrates very intense FDG uptake.

The ring-like configuration of this FDG-avid soft tissue is often best illustrated on the coronal MIP view.

Unless uptake in this ring is focal or asymmetric (or accompanied by a soft tissue lesion on the co-registered CT images), even extremely intense Waldeyer uptake is considered normal.