Computed Tomography (CT)

Primer

Computed Tomography (CT) uses a series of x-rays of the head taken from many different directions. CT scanning requires the use of a computer 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.

When to order CT Head?

Structural neuroimaging is useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture, and old age.[1][2]

Comparison

Indications for Choosing CT vs. MRI

CT Screening exam, delirium, acute hemorrhage, skull injury, calcified lesions,[3] and patients who cannot tolerate lengthier MRI.
MRI Sustained confusion, subtle cognitive deficits, atypical clinical findings, abrupt personality changes with neurological signs/symptoms, brain injuries.

Resources

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Teaching

References

1) Coentre, R., Silva-dos-Santos, A., & Talina, M. C. (2016). Retrospective study on structural neuroimaging in first-episode psychosis. PeerJ, 4, e2069.
2) Masdeu, J. C. (2011). Neuroimaging in psychiatric disorders. Neurotherapeutics, 8(1), 93-102.
3) Saade, C., Najem, E., Asmar, K., Salman, R., El Achkar, B., & Naffaa, L. (2019). Intracranial calcifications on CT: an updated review. Journal of radiology case reports, 13(8), 1.