Display Settings:


Send to:

Choose Destination
J Stroke Cerebrovasc Dis. 2014 May-Jun;23(5):1019-23. doi: 10.1016/j.jstrokecerebrovasdis.2013.08.018. Epub 2013 Oct 6.

Noninvasive evaluation of collateral blood flow through circle of willis in cervical carotid stenosis using selective magnetic resonance angiography.

Author information

  • 1Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Japan.
  • 2Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Japan. Electronic address: masasaki@iwate-med.ac.jp.
  • 3Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
  • 4Hitachi Medical Corporation, Tokyo, Japan.



Preoperative assessment of intracranial collateral circulation is helpful in predicting cerebral ischemia during surgical procedures for cervical internal carotid artery (ICA) stenosis. However, magnetic resonance angiography (MRA) and other less-invasive techniques cannot evaluate collateral blood flow because these techniques are nonselective. Hence, by using a newly developed selective MRA technique, we attempted to visualize collaterals via the circle of Willis in patients with ICA stenosis.


Twelve patients who underwent carotid endarterectomy were prospectively examined with a 1.5-T MR scanner. Both selective and nonselective MRA were obtained using a 3-dimensional time-of-flight technique, with or without a cylindrical saturation pulse that suppresses the flow signal from the region of the target ICA. Maximum intensity projection MRA images were generated and compared with digital subtraction angiography (DSA) images.


In all patients, the distal flow signal of the ipsilateral ICA was completely suppressed on selective MRA compared with nonselective MRA. In addition, collateral blood flow through the anterior and posterior communicating arteries was visualized in 5 and 2 patients, respectively. These findings corresponded well with the DSA imaging.


Selective MRA techniques can readily suppress signals from the distal blood flow of the target artery and visualize the presence of collateral flows through the circle of Willis in patients with cervical ICA stenosis.

Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.


Magnetic resonance angiography; carotid endarterectomy; cervical carotid stenosis; circle of Willis; collateral blood flow

[PubMed - in process]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk