Normal FDG Uptake in the Lingual Tonsils

Accurate interpretation of PET images requires familiarity with the normal patterns of uptake and intensities. In the head and neck, intense FDG activity can be seen in the components of Waldeyer's ring. More than 95% of normal subjects have FDG activity greater than blood pool in the palatine tonsils (mean SUV = 3.48) and lingual tonsils (mean SUV = 3.11). This physiologic uptake has an inverse relationship with age for the palatine tonsils.

The image above shows fused (top row) and maximum intensity projections in a patient with no disease in the head and neck. There is intense FDG activity above blood pool (SUV_max = 7).

References

• Nakamoto Y, Tatsumi M, Hammoud D, Cohade C, Osman MM, Wahl RL. Normal FDG distribution patterns in the head and neck: PET/CT evaluation. Radiology. 2005 Mar;234(3):879-85.