In PET-CT using F-18 FDG, a standardised uptake value (SUVmax) is used to quantify metabolic activity. FDG is taken up by metabolically active cells via glucose transporters (GLUT). Which normal tissue can show HIGH physiological FDG uptake that may mimic pathology on PET-CT, requiring careful interpretation?
- A Liver parenchyma due to gluconeogenesis
- B Resting skeletal muscle
- C Brown adipose tissue (BAT), especially in the cervical-supraclavicular region in cold ambient conditions ✓
- D Cerebellum in all patients
Correct answer: C. Brown adipose tissue (BAT), especially in the cervical-supraclavicular region in cold ambient conditions
Explanation
Brown adipose tissue (BAT) is metabolically highly active due to uncoupled mitochondrial oxidation (thermogenesis) and expresses high levels of GLUT4 receptors, leading to intense FDG uptake that can mimic lymphoma or metastatic disease in the cervical, axillary, supraclavicular, and paravertebral regions. This is especially pronounced in young lean patients in cold ambient temperatures. Liver has moderate uniform background uptake. Resting skeletal muscle has low uptake. Cerebellum has physiological but moderate uptake.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.