Which imaging method detects brain activity by measuring glucose metabolism during a task?

Which imaging method detects brain activity by measuring glucose metabolism during a task?

• A. PET Scan
• B. MRI
• C. Angiography
• D. EEG

Answer: (A)

Brain activity during a task is reflected in increased glucose use, and PET scanning is designed to visualize that metabolic activity. A PET scan uses a radioactive form of glucose (FDG); when neurons are more active, they take up more FDG and trap it in their cells. The scanner then detects the emitted radiation to create a map of regional glucose metabolism, showing which areas are engaged during the task. This metabolic measure provides a functional picture of brain activity over a period rather than moment-to-moment electrical signals. In contrast, MRI can show structural details and, when used functionally, relies on blood flow changes as an indirect proxy for activity; EEG records electrical activity with high temporal precision but limited spatial localization; angiography highlights blood vessels rather than metabolic processes.

Brain activity during a task is reflected in increased glucose use, and PET scanning is designed to visualize that metabolic activity. A PET scan uses a radioactive form of glucose (FDG); when neurons are more active, they take up more FDG and trap it in their cells. The scanner then detects the emitted radiation to create a map of regional glucose metabolism, showing which areas are engaged during the task. This metabolic measure provides a functional picture of brain activity over a period rather than moment-to-moment electrical signals. In contrast, MRI can show structural details and, when used functionally, relies on blood flow changes as an indirect proxy for activity; EEG records electrical activity with high temporal precision but limited spatial localization; angiography highlights blood vessels rather than metabolic processes.