Brain Imaging

Question 1

Computerized tomography (CT) scan

Answer 1

Taking a number of x-rays of a particular section of a person’s body or brain—passes through tissues of different densities at different rates, allowing a computer to construct an overall image of the area of the brain being scanned.

Question 2

Positron emission tomography (PET) scan

Answer 2

Creates pictures of the living, active brain—individual drinks or is injected with mildly radioactive substance called a tracer. More active = more blood flow. Shows little detail and was replaced by the fMRI.

Question 3

Magnetic resonance imaging (MRI)

Answer 3

A person is placed inside a machine that generates a strong magnetic field—causes hydrogen atoms to move—tissues of different densities give off different signals, which a computer interprets and displays on a monitor.

Question 4

Functional magnetic resonance imaging (fMRI)

Answer 4

Operating on the same principles, but it shows changes in brain activity over time by tracking blood flow and oxygen levels—provides a more detailed images of the brains structure as well as better accuracy in time.

Question 5

Electroencephalography (EEG)

Answer 5

Provides a measure of a brain’s electrical activity without information on the actual location of the activity—the signals reviewed by the electrodes result in a printout of the electrical activity of their brain or brain waves. Helps researchers study sleep patterns among individuals with sleep disorders.