Which imaging modality is known as a PET scan?

Which imaging modality is known as a PET scan?

• A. X-ray Computed Tomography
• B. Ultrasound
• C. Positron Emission Tomography
• D. Magnetic Resonance Imaging

Answer: (C)

PET scans visualize metabolic activity by using tracers that emit positrons. After administration, these radiotracers accumulate in tissues based on their metabolic activity. When a positron encounters an electron, they annihilate and produce two gamma photons that travel in opposite directions. The PET detector picks up these coincident photons and uses them to reconstruct a 3D image showing how actively different tissues are using the tracer, often reflecting glucose metabolism. A common tracer is FDG, a glucose analogue, which highlights areas of high metabolic demand such as certain cancers or brain regions. This functional information is what sets PET apart from the other modalities. X-ray CT builds images from X-rays to show anatomy and density differences. Ultrasound uses sound waves to image soft tissues and movement. MRI uses magnetic fields and radiofrequency pulses to image tissues with superb soft-tissue contrast, primarily based on hydrogen proton behavior. PET, by contrast, reveals physiological processes rather than just structure, and is frequently combined with CT or MRI in hybrid scanners to correlate metabolic activity with anatomy.

PET scans visualize metabolic activity by using tracers that emit positrons. After administration, these radiotracers accumulate in tissues based on their metabolic activity. When a positron encounters an electron, they annihilate and produce two gamma photons that travel in opposite directions. The PET detector picks up these coincident photons and uses them to reconstruct a 3D image showing how actively different tissues are using the tracer, often reflecting glucose metabolism. A common tracer is FDG, a glucose analogue, which highlights areas of high metabolic demand such as certain cancers or brain regions.

This functional information is what sets PET apart from the other modalities. X-ray CT builds images from X-rays to show anatomy and density differences. Ultrasound uses sound waves to image soft tissues and movement. MRI uses magnetic fields and radiofrequency pulses to image tissues with superb soft-tissue contrast, primarily based on hydrogen proton behavior. PET, by contrast, reveals physiological processes rather than just structure, and is frequently combined with CT or MRI in hybrid scanners to correlate metabolic activity with anatomy.