European Radiology

, Volume 27, Issue 10, pp 4145–4152 | Cite as

Importance of variants in cerebrovascular anatomy for potential retrograde embolization in cryptogenic stroke

  • Michael MarklEmail author
  • Edouard Semaan
  • LeRoy Stromberg
  • James Carr
  • Shyam Prabhakaran
  • Jeremy Collins
Magnetic Resonance



To test the hypothesis that variants in cerebrovascular anatomy will affect the number of patients demonstrating a plausible retrograde embolization mechanism from plaques in the descending aorta (DAo).


Thirty-five patients (aged 63 ± 17 years) with cryptogenic stroke underwent 4D flow MRI for the assessment of aortic 3D blood flow and MR angiography for the evaluation of circle of Willis, posterior circulation, and aortic arch architecture. In patients with proven DAo plaque, retrograde embolization was considered a potential mechanism if retrograde flow extended from the DAo to a supra-aortic vessel supplying the cerebral infarct territory.


Retrograde embolization with matching cerebral infarct territory was detected in six (17%) patients. Circle of Willis and aortic arch variant anatomy was found in 60% of patients, leading to reclassification of retrograde embolization risk as present in three (9%) additional patients, for a total 26% of cryptogenic stroke patients.


4D flow MRI demonstrated 26% concordance with infarct location on imaging with retrograde diastolic flow into the feeding vessels of the affected cerebral area, identifying a potential etiology for cryptogenic stroke. Our findings further demonstrate the importance of cerebrovascular anatomy when determining concordance of retrograde flow pathways with vascular stroke territory from DAo plaques.

Key points

Retrograde embolization from descending aortic plaques constitutes a plausible etiology in cryptogenic stroke.

Common variants of cerebrovascular anatomy are important in determining retrograde embolization mechanism.

Variant cerebrovascular anatomy can link retrograde flow pathways with vascular stroke territory.


4D flow MRI Stroke Plaque Retrograde flow Circle of Willis 


Compliance with ethical standards


The scientific guarantor of this publication is Michael Markl.

Conflict of interest

The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.


This study has received funding through NIH NHLBI grant R21 HL132357.

Statistics and biometry

No complex statistical methods were necessary for this paper.

Ethical approval

Institutional Review Board approval was obtained.

Study subjects or cohorts overlap

Written informed consent was waived by the Institutional Review Board.


• retrospective

• cross-sectional study

• performed at one institution


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Copyright information

© European Society of Radiology 2017

Authors and Affiliations

  • Michael Markl
    • 1
    • 2
    Email author
  • Edouard Semaan
    • 1
  • LeRoy Stromberg
    • 3
    • 4
  • James Carr
    • 1
  • Shyam Prabhakaran
    • 3
  • Jeremy Collins
    • 1
  1. 1.Department of Radiology, Feinberg School of MedicineNorthwestern UniversityChicagoUSA
  2. 2.Department of Biomedical Engineering, McCormick School of EngineeringNorthwestern UniversityChicagoUSA
  3. 3.Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoUSA
  4. 4.Department of RadiologyEdward HospitalNapervilleUSA

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