Editing Transient ischemic attack (section)

===Imaging===
According to guidelines from the [[American Heart Association]] and [[American Stroke Association]] Stroke Council, patients with TIA should have head imaging "within 24 hours of symptom onset, preferably with magnetic resonance imaging, including diffusion sequences".<ref name=pmid19423857/> MRI is a better imaging modality for TIA than computed tomography (CT), as it is better able to pick up both new and old ischemic lesions than CT. CT, however, is more widely available and can be used particularly to rule out intracranial hemorrhage.<ref name=pmid23062043/> Diffusion sequences can help further localize the area of ischemia and can serve as prognostic indicators.<ref name=":7" /> Presence of ischemic lesions on [[Diffusion-weighted imaging|diffusion weighted imaging]] has been correlated with a higher risk of stroke after a TIA.<ref>{{cite journal | vauthors = Redgrave JN, Coutts SB, Schulz UG, Briley D, Rothwell PM | title = Systematic review of associations between the presence of acute ischemic lesions on diffusion-weighted imaging and clinical predictors of early stroke risk after transient ischemic attack | journal = Stroke | volume = 38 | issue = 5 | pages = 1482–1488 | date = May 2007 | pmid = 17379821 | doi = 10.1161/strokeaha.106.477380 | doi-access = free }}</ref>

Vessels in the head and neck may also be evaluated to look for [[Atherosclerosis|atherosclerotic]] lesions that may benefit from interventions, such as [[carotid endarterectomy]]. The vasculature can be evaluated through the following imaging modalities: [[magnetic resonance angiography]] (MRA), [[CT angiography]] (CTA), and [[carotid ultrasonography]]/transcranial doppler ultrasonography.<ref name=pmid19423857/> Carotid ultrasonography is often used to screen for carotid artery stenosis, as it is more readily available, is noninvasive, and does not expose the person being evaluated to radiation. However, all of the above imaging methods have variable [[Sensitivity and specificity|sensitivities and specificities]], making it important to supplement one of the imaging methods with another to help confirm the diagnosis (for example: screen for the disease with ultrasonography, and confirm with CTA).<ref name=":12">{{cite web |title=Final Recommendation Statement: Carotid Artery Stenosis: Screening |url=https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/carotid-artery-stenosis-screening |website=United States Preventive Services Taskforce|date=8 July 2014 }}</ref> Confirming a diagnosis of carotid artery stenosis is important because the treatment for this condition, [[carotid endarterectomy]], can pose significant risk to the patient, including heart attacks and strokes after the procedure.<ref name=":12" /> For this reason, the [[U.S. Preventive Services Task Force]] (USPSTF) "recommends against screening for asymptomatic carotid artery stenosis in the general adult population".<ref name=":12" /> This recommendation is for asymptomatic patients, so it does not necessarily apply to patients with TIAs as these may in fact be a symptom of underlying carotid artery disease (see "Causes and Pathogenesis" above). Therefore, patients who have had a TIA may opt to have a discussion with their clinician about the risks and benefits of screening for carotid artery stenosis, including the risks of surgical treatment of this condition.

Cardiac imaging can be performed if head and neck imaging do not reveal a vascular cause for the patient's TIA (such as atherosclerosis of the carotid artery or other major vessels of the head and neck). Echocardiography can be performed to identify [[patent foramen ovale]] (PFO), valvular stenosis, and atherosclerosis of the aortic arch that could be sources of clots causing TIAs, with [[transesophageal echocardiography]] being more sensitive than [[transthoracic echocardiography]] in identifying these lesions.<ref name=pmid19423857/>