Merck Manual

Please confirm that you are a health care professional

honeypot link

Computed Tomography (CT) in Neurologic Disorders


Michael C. Levin

, MD, College of Medicine, University of Saskatchewan

Last full review/revision Dec 2018| Content last modified Dec 2018
Click here for Patient Education
Topic Resources

CT provides rapid, noninvasive imaging of the brain and skull. CT is superior to magnetic resonance imaging (MRI) in visualizing fine bone detail in (but not the contents of) the posterior fossa, base of the skull, and spinal canal.

Normal Head CT Scan (Adult, Age 30)
Normal Head CT Scan (Adult, Age 74)

Noncontrast CT is used to rapidly detect acute hemorrhage and various gross structural changes without concern about contrast allergy or renal failure.

A radiopaque contrast agent helps detect brain tumors and brain abscesses. With an intrathecal agent, CT can outline abnormalities encroaching on the brain stem, spinal cord, or spinal nerve roots (eg, meningeal carcinoma, herniated disk) and may detect a syrinx in the spinal cord.

CT angiography using a contrast agent can show the cerebral blood vessels, obviating the need for MRI or angiography.

Adverse effects of contrast agents include allergic reactions and contrast nephropathy.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Test your knowledge

Numbness is defined as loss of sensation, either partial or complete. Numbness can occur from dysfunction anywhere along the pathway from the sensory receptors up to the cerebral cortex. A patient with dysfunction in which of the following CNS areas is most likely to present with facial and body numbness on the same side, plus an inability to perceive multiple stimuli of the same type simultaneously?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest