Title:9.4T Magnetic Resonance Imaging of the Mouse Circle of Willis Enables Serial Characterization of Flow-Induced Vascular Remodeling by Computational Fluid Dynamics
Volume: 15
Issue: 4
Author(s): Vincent M. Tutino*, Hamidreza Rajabzadeh-Oghaz, Anusha R. Chandra, Liza C. Gutierrez, Ferdinand Schweser, Marilena Preda, Aichi Chien, Kunal Vakharia, Ciprian Ionita, Adnan Siddiqui and John Kolega
Affiliation:
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14260,United States
Keywords:
Animal model, carotid artery ligation, hemodynamics, computational fluid dynamics, magnetic resonance imaging,
vascular corrosion casting.
Abstract: Background: The neurovasculature dynamically responds to changes in cerebral blood
flow by vascular remodeling processes. Serial imaging studies in mouse models could help characterize
pathologic and physiologic flow-induced remodeling of the Circle of Willis (CoW).
Method: We induced flow-driven pathologic cerebral vascular remodeling in the CoW of mice
(n=3) by ligation of the left Common Carotid Artery (CCA), and the right external carotid and
pterygopalatine arteries, increasing blood flow through the basilar and the right internal carotid arteries.
One additional mouse was used as a wild-type control. Magnetic Resonance Imaging (MRI)
at 9.4 Tesla (T) was used to serially image the mouse CoW over three months, and to obtain threedimensional
images for use in Computational Fluid Dynamic (CFD) simulations. Terminal vascular
corrosion casting and scanning electron microscope imaging were used to identify regions of
macroscopic and microscopic arterial damage.
Results: We demonstrated the feasibility of detecting and serially measuring pathologic cerebral
vascular changes in the mouse CoW, specifically in the anterior vasculature. These changes were
characterized by bulging and increased vessel tortuosity on the anterior cerebral artery and aneurysm-
like remodeling at the right olfactory artery origin. The resolution of the 9.4T system further
allowed us to perform CFD simulations in the anterior CoW, which showed a correlation between
elevated wall shear stress and pathological vascular changes.
Conclusion: In the future, serial high-resolution MRI could be useful for characterizing the flow
environments corresponding to other pathologic remodeling processes in the mouse CoW, such as
aneurysm formation, subarachnoid hemorrhage, and ischemia.
