Q: An article in a recent news magazine mentioned a PET Scan. What is it?
A: PET is an acronym that stands for positron emission tomography. It is a testing modality that measures the rate at which glucose is utilized by neurons (thinking cells of the brain).
Briefly, a small amount of radioactive glucose is injected into the blood stream and the PET camera (a picture is worth a thousand words) makes a recording of the location and rate of glucose metabolism in the brain. A higher concentration of glucose in a particular segment correlates with that segment's neuronal activity in response to a specific task.
PET Scans have revealed a wealth of information about brain function and have enabled researchers to actually assign responsibility for certain functions to specific portions of the brain and to explain individual differences at the neuron level.
PET Scans are more commonly performed in Europe due, in part, to more extensive informed consent issues and litigation patterns in America. Watch for reports of other brain-testing modalities such as MRI and fMRI.