What is the utility of MRI in the diagnosis of stroke?
MRI with diffusion-weighted imaging is particularly useful in diagnosing stroke, as it helps confirm the diagnosis and can help with patient education and prognostication. A cost-effectiveness analysis of the use of MRI in patients with TIA reported in 2014 concluded that MRI was generally not cost-effective, although there might be utility to MRI in this population if the imaging is done >1 week after onset of symptoms and with a blood-sensitive sequence, if the clinical team is considering unusual causes of symptoms, or if symptoms are related to ipsilateral high-grade stenosis. Predictive scores that incorporate MRI findings (eg, ABCD2 -I and -I) are better able to discriminate high risk of early stroke from low risk of early stroke than predictive scores that do not incorporate MRI findings (eg, ABCD2 ) when MRI is done within 7 days of onset of symptoms. 