CT of the head
Author:
Mikael Häggström [notes 1]
Contents
Planning
- Indications for contrast
Most CTs of the head are made without IV contrast, as there is limited advantage of contrast for initial investigations for stroke, intracranial bleeding or skeletal trauma. In the acute setting, it is also acceptable to have a CT head without contrast if a tumor is part of a list of differential diagnoses but not the most likely cause. It is then generally possible to to a complementary MRI of the head if a suspicion of a tumor remains. However, if a tumor is strongly suspected in an initial acute setting, it is usually appropriate to do a CT with and without IV contrast.
This is indicated in identification and characterization of aneurysms, stenosis or other occlusive diseases, arteriovenous malformations, vessel dissections, sinus thrombosis, idiopathic hemorrhage, and other vascular pathologies.[1]
Normal anatomy
Associated diseases and conditions
Brain
Extra-cerebral
Evaluation
Apart from any specific requests in the referral, it is appropriate to scroll through the brain in at least two planes in:
- Parenchymal window, for (at least in people over age 50-60) ischemia or stroke
- Bleeding window (such as center at 80 HU and width 150 HU)
- Bone window for fracture, at least in emergent exams. It also facilitates a quick glance of the mastoid air cells, the middle ears and the paranasal sinuses in case of fluid/mucus filling.
Very common findings
- Periventricular white matter lesions (annotated).jpg
Periventricular white matter lesions should be mentioned since they such patients have increased stroke risk.[2]
Report
A succint report only needs to respond to the requests in the referral, as well as additional present findings found upon evaluation.
A somewhat more detailed report includes even the absence of:
- Intracranial bleeding.
- Signs of infarction.
- Skull fracture
- See also: General notes on reporting
Notes
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Radlines:Authorship for details.
References
- ↑ Lian, K.; Bharatha, A.; Aviv, R.I.; Symons, S.P. (2011). "Interpretation Errors in CT Angiography of the Head and Neck and the Benefit of Double Reading ". American Journal of Neuroradiology 32 (11): 2132–2135. doi:. ISSN 0195-6108.
- ↑ Vermeer, Sarah E.; Hollander, Monika; van Dijk, Ewoud J.; Hofman, Albert; Koudstaal, Peter J.; Breteler, Monique M.B. (2003). "Silent Brain Infarcts and White Matter Lesions Increase Stroke Risk in the General Population ". Stroke 34 (5): 1126–1129. doi:. ISSN 0039-2499.
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