PET images show blood flow and metabolic processes rather than anatomical like SPECT.

PET images show blood flow and metabolic processes rather than anatomical like SPECT.

• A. Bone density
• B. Blood flow and metabolic processes
• C. Electrical activity
• D. Tissue elasticity

Answer: (B)

PET imaging focuses on physiological function—specifically blood flow and metabolic activity—rather than static anatomy. The radiotracers used in PET participate in metabolic pathways or reflect perfusion, so the distribution of tracer shows how actively tissues are metabolizing or receiving blood supply. For example, FDG behaves like glucose, so areas with high uptake reveal high metabolic demand, such as active brain regions or tumors. This functional view is why PET highlights activity over structure, and PET data are often fused with CT or MRI to add anatomical context. The other options describe properties PET does not measure: bone density is a structural mineral measure, electrical activity is captured by EEG/MEG, and tissue elasticity is assessed with elastography. SPECT also provides functional information but PET generally offers higher sensitivity and more precise quantification of metabolic processes.

PET imaging focuses on physiological function—specifically blood flow and metabolic activity—rather than static anatomy. The radiotracers used in PET participate in metabolic pathways or reflect perfusion, so the distribution of tracer shows how actively tissues are metabolizing or receiving blood supply. For example, FDG behaves like glucose, so areas with high uptake reveal high metabolic demand, such as active brain regions or tumors. This functional view is why PET highlights activity over structure, and PET data are often fused with CT or MRI to add anatomical context. The other options describe properties PET does not measure: bone density is a structural mineral measure, electrical activity is captured by EEG/MEG, and tissue elasticity is assessed with elastography. SPECT also provides functional information but PET generally offers higher sensitivity and more precise quantification of metabolic processes.