PET aids in diagnosis by detecting functional changes and quantifying what in lesions?

• A. Vessel anatomy
• B. Functional changes and activity
• C. Bone mineral density
• D. Electrical conduction

Answer: (B)

PET imaging focuses on how tissues function by measuring metabolic activity. It detects functional changes and quantifies how active a lesion is, typically using a radiotracer like FDG that mirrors glucose metabolism. Tissues with higher metabolic rates take up more tracer, and this uptake is quantified (often as SUV) to compare lesions, assess malignancy, and monitor treatment response. Because PET reveals biology rather than just structure, it distinguishes metabolic activity from anatomy, which is why choices describing vessel anatomy, bone density, or electrical conduction fit other imaging modalities rather than PET.