Computed tomography of the head

Computed tomography of the head
Diagnostics
Computer tomography of human brain, from base of the skull to top. Taken with intravenous contrast medium.
ICD-9-CM	87.03
OPS-301 code	3-200, 3-220

Computed tomography (CT) of the head or Computed Axial Tomography (CAT) scanning uses a series of x-rays of the head taken from many different directions. Typically used for quickly viewing brain injuries, CT scanning uses a computer program that performs a numerical integral calculation (the inverse Radon transform) on the measured x-ray series to estimate how much of an x-ray beam is absorbed in a small volume of the brain. Typically the information is presented as cross sections of the brain.^[1]

In approximation, the denser a material is, the whiter a volume of it will appear on the scan (just as in the more familiar "flat" X-rays). CT scans are primarily used for evaluating swelling from tissue damage in the brain and in assessment of ventricle size. Modern CT scanning can provide reasonably good images in a matter of minutes.

Computed tomography (CT) has become the diagnostic modality of choice for head trauma due to its accuracy, reliability, safety, and wide availability. The changes in microcirculation, impaired auto-regulation, cerebral edema, and axonal injury start as soon as head injury occurs and manifest as clinical, biochemical, and radiological changes. Proper therapeutic management of brain injury is based on correct diagnosis and appreciation of the temporal course of the disease process. CT scan detects and precisely localizes the intracranial hematomas, brain contusions, edema and foreign bodies. Because of the widespread availability of CT, there is reduction in arteriography, surgical intervention and skull radiography.http://www.jpmsonline.com/jpms-vol1-issue3-pages78-82-oa.html

One advantage over a brain MRI is in the evaluation of intracerebral calcifications.^[2]

See also

• Neuroimaging

References

1. ^ Malcom Jeeves (1994). Mind Fields: Reflections on the Science of Mind and Brain. Grand Rapids, MI: Baker Books., p. 21
2. ^ Ebel, Klaus-Dietrich; Benz-Bohm, Gabriele (1999). Differential diagnosis in pediatric radiology. Thieme. pp. 538–. ISBN 9783131081315. http://books.google.com/books?id=SGMrGn49QZUC&pg=PA538. Retrieved 18 July 2011.