Computed tomography, also known as a CT scan, combines x-rays and computer technology to produce rapid, clear, two-dimensional images of bones, organs, and tissues. Occasionally a contrast dye is injected into the bloodstream to highlight the different tissues in the brain and to detect inflammation of the meninges.
CT scans can also detect:
- Bone and blood vessel irregularities
- Certain brain tumors and cysts
- Herniated discs
- Spinal stenosis (narrowing of the spinal canal)
- Blood clots or intracranial bleeding in patients with stroke
- Brain damage from a head injury
- Other disorders.
Magnetic resonance imaging (MRI) uses computer-generated radio waves and a strong magnet to produce detailed images of body structures, including tissues, organs, bones, and nerves.
The pictures, which are clearer than those produced by CT, can help identify:
- Brain and spinal cord inflammation
- Eye disease
- Blood vessel irregularities that may lead to stroke.
A contrast dye may be injected prior to the test to reveal more detail.