Don’t perform CT imaging for headache when MRI is available, except in emergency settings.
|Rationale and Comments:||When neuroimaging for headache is indicated, MRI is preferred over CT, except in emergency settings when hemorrhage, acute stroke, or head trauma are suspected. MRI is more sensitive than CT for the detection of neoplasm, vascular disease, posterior fossa and cervicomedullary lesions, and high and low intracranial pressure disorders. CT of the head is associated with substantial radiation exposure, which may elevate the risk of later cancers, while there are no known biologic risks from MRI.|
|References:||• Neuroimaging for the evaluation of chronic headaches: an evidence-based analysis. Ont Health Technol Assess Ser. 2010;10(26):1-57.
Evans R. Diagnostic testing for migraine and other primary headaches. Neurol Clin. 2009 May;27(2):393-414.
• Semelka RC, Armao DM, Elias J Jr, Huda W. Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI. J Magn Reson Imaging. 2007;25(5):900-09.
• Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med. 2007;357(22):2277-84.