Question

1. which diagnostic test uses radioactive tracers to detect brain changes?

polysomnogram
positron emission tomography
magnetic resonance imaging
computed tomography

Explanation:

• Polysomnogram: Measures sleep - related parameters like brain waves (EEG), eye movements (EOG), muscle activity (EMG), etc. It does not use radioactive tracers.
• Positron emission tomography (PET): Involves the use of radioactive tracers (such as fluorodeoxyglucose - FDG for metabolic studies). The tracers are taken up by cells (in the brain, for example), and the positrons emitted from the decay of the radioactive isotope interact with electrons in the body, and the resulting gamma rays are detected to create an image of brain function and changes.
• Magnetic resonance imaging (MRI): Uses a strong magnetic field and radio waves to create detailed images of the brain's structure. No radioactive tracers are used.
• Computed tomography (CT): Uses X - rays to create cross - sectional images of the brain. X - rays are not radioactive tracers in the sense of a substance injected for functional imaging like in PET.

Answer:

Positron emission tomography