MR Imaging in Acute Stroke: Basics 

Thanks! You'll encounter a range of performance reported throughout the medical literature, and the reference I used was one that seemed closest to my personal observations over the years. The reference is: "CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute ischemic stroke" by Fiebach et al. in Stroke (2002). A reference that reported lower sensitivity, but higher specificity is "Certainty of Stroke Diagnosis: Incremental Benefit with CT Perfusion over Non-contrast CT and CT Angiography" by Hopyan et al. in Radiology (2010), where a sensitivity of 52.5% and specificity of 84.4% are reported for radiologists diagnosing stroke on non-contrast head CT. There's another reference that reports even lower sensitivity and higher specificity for non-contrast head CT: "Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison" by Chalela et al. in The Lancet (2007), where they report: For acute stroke: - CT sensitivity 26% - MR sensitivity 83% - CT specificity 98% - MR specificity 97% For acute ischemic stroke: - CT sensitivity 16% - MR sensitivity 83% - CT specificity 98% - MR specificity 96%