Evaluation Procedures

How is stroke diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for stroke may include the following.

Imaging tests of the brain:

• computed tomography scan (Also called a CT or CAT scan.)-a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, 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 general x-rays; used to detect abnormalities and help identify the location or type of stroke.
• magnetic resonance imaging (MRI)-a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body; an MRI uses magnetic fields to detect small changes in brain tissue that helps to locate and diagnose stroke.
• radionuclide angiography-a nuclear brain scan in which radioactive compounds are injected into a vein in the arm, and a machine (similar to a Geiger counter) creates a map showing their uptake into different parts of the head. The images show how the brain functions rather than its structure. This test can often detect areas of decreased blood flow and tissue damage.
• computed tomographic angiography (CTA) - an x-ray image of the blood vessels. A CT angiogram uses CT technology to obtain images of blood vessels.

Tests that evaluate the brain's electrical activity:

• electroencephalogram (EEG)-a procedure that records the brain's continuous, electrical activity by means of electrodes attached to the scalp.
• evoked potentials-procedures that record the brain's electrical response to visual, auditory, and sensory stimuli.