CT or MRI for brain aneurysm scan? - Experts only?
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According to the American Heart Association statement, CT (standard computed tomography) with or without contrast agents is considered too imprecise for adequate diagnosis of brain aneurysms. However, CTA (computer tomographic angiography) may pinpoint aneurysms as small as 2 to 3 mm. Magnetic resonance Angiography (MRA) is useful for screening, especially for aneurysms 3 to 5 mm or more in diameter, and is the most heavily used test.
However, MRA’s are expensive ($500-$1,000 or more) so there is currently only support for screening people with a significant demonstrated risk. Moreover, the MRI machines distributed throughout the U.S. vary in quality based on their prices, translating to varied degrees of detection accuracy making nation-wide effective screening difficult. If you choose to be screened, ensure that a minimum threshold machine of xxx accuracy, xxx specificity is used.
CTA and MRA reportedly have the following efficiency limitations: sensitivity 76-98%, specificity 85-100%, with TCD being poorer (Wardlaw and White, 2000). Even then, many of the study subjects had an aneurysm or recent subarachnoid aneurismal hemorrhage, which would artificially increase the accuracy. The detection rate of the scans declines proportionally to the size of the aneurysm, typically. They are poor detectors for aneurysms smaller than 5 mm in diameter, which account for approximately one third of unruptured aneurysms.
I am not an expert.Just completed my medicine.
Just copied this for your information.
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