What is the role of MRI in the diagnosis of vertebrobasilar stroke?

Updated: Aug 09, 2021
  • Author: Vladimir Kaye, MD; Chief Editor: Stephen Kishner, MD, MHA  more...
  • Print


MRI is more sensitive than CT in the identification of ischemia (since bone does not degrade the image). Newer techniques, including flow suppression and the production of diffusion-weighted and perfusion-weighted images, make MRI a very powerful tool for the exclusion of intraparenchymal hemorrhage or edema and for the identification of early and potentially reversible ischemia. [19, 20, 25, 26, 27]

MRI and magnetic resonance angiography (MRA) are very helpful in finding occult lesions, such as demyelinating plaques, tumors, vertebrobasilar dolichoectasia, or dissection. [28, 29, 30] MRA has a sensitivity of up to 97% and a specificity of up to 98% when used to identify vertebrobasilar occlusion.

A limitation of MRA is its tendency to overestimate the degree of stenosis. This overestimation occurs because the production of a vessel's image in MRA is a based on a flow-related phenomenon; hence, the presence of severe stenosis with significant flow compromise may result in poor visualization of a vessel and cause the MRA image to resemble vascular occlusion.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!