PET imaging uses what type of emissions to produce images?

PET imaging uses what type of emissions to produce images?

• A. Positron emissions
• B. Gamma rays from fission
• C. X-rays
• D. Neutrons

Answer: (A)

PET imaging relies on radiotracers that decay by emitting positrons. When a positron is emitted, it travels a short distance and annihilates with an electron, producing two gamma photons that travel in opposite directions. The scanner detects these gamma photon pairs and uses them to reconstruct where the tracer is, forming the image. So the initiating emission is positron emission from the tracer, even though the images are ultimately created from the resulting gamma photons produced by annihilation. Other options describe emissions not used in PET—gamma rays from fission, X-rays, or neutrons.

PET imaging relies on radiotracers that decay by emitting positrons. When a positron is emitted, it travels a short distance and annihilates with an electron, producing two gamma photons that travel in opposite directions. The scanner detects these gamma photon pairs and uses them to reconstruct where the tracer is, forming the image. So the initiating emission is positron emission from the tracer, even though the images are ultimately created from the resulting gamma photons produced by annihilation. Other options describe emissions not used in PET—gamma rays from fission, X-rays, or neutrons.