Different types of Brain Scans

EEG

Electroencephalogram

EEG

An EEG, or electroencephalogram, is a test that records the electrical signals of the brain. Doctors use it to help diagnose epilepsy and sleep disorders.

Before

Let your doctor know about any medications -- both prescription and over-the-counter -- and supplements you're taking.

Wash your hair the night before the test. Don't use any leave-in conditioning or styling products afterward.

During

You lie down on the exam table or bed, and a technician puts about 20 small sensors on your scalp. These sensors, called electrodes, pick up activity from cells inside your brain called neurons and send them to a machine, where they show up as a series of lines recorded on moving paper or displayed on a computer screen.

You'll relax with your eyes open first, then with them closed. The technician may ask you to breathe deeply and rapidly or to stare at a flashing light, because both of these can change your brain wave patterns.

After

The technician will take the electrodes off and wash off the glue that held them in place. You can use a little fingernail polish remover at home to get rid of any leftover stickiness.

Unless you're actively having seizures or your doctor says you shouldn't, you can drive home. But if the EEG was done overnight, it's better to have someone else drive you.

CT

Computed Tomograph

CT

Computed tomography (CT or CAT scan) is a noninvasive diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than standard X-rays.

In standard X-rays, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam after it passes through skin, bone, muscle, and other tissue. While much information can be obtained from a standard X-ray, a lot of detail about internal organs and other structures is not available.

PET

Positron Emission Tomography

PET

A brain positron emission tomography (PET) scan is an imaging test that allows doctors to see how your brain is functioning. The scan captures images of the activity of the brain after radioactive “tracers” have been absorbed into the bloodstream. These tracers are “attached” to compounds like glucose (sugar).During a PET scan, the patient is first injected with a glucose (sugar) solution that contains a very small amount of radioactive material. ... A PET scan can be used to detect cancerous tissues and cells in the body that may not always be found through computed tomography (CT) or magnetic resonance imaging (MRI). A positron emission tomography (PET) scan is an imaging test that allows your doctor to check for diseases in your body. The scan uses a special dye that has radioactive tracers. These tracers are injected into a vein in your arm. Your organs and tissues then absorb the tracer. During a PET scan, the patient is first injected with a glucose (sugar) solution that contains a very small amount of radioactive material. ... A PET scan can be used to detect cancerous tissues and cells in the body that may not always be found through computed tomography (CT) or magnetic resonance imaging (MRI).

MRI