Characterization of Cerebral Aneurysms for Assessing Risk of Rupture By Using Patient-Specific Computational Hemodynamics Models
Juan R. Cebrald,
Marcelo A. Castrod,
James E. Burgessb,
Richard S. Pergolizzia,e,
Michael J. Sheridanc and
Christopher M. Putmana,e
a Department of Radiology, Inova Fairfax Hospital, Falls Church, VA
b Department of Neurosurgery, Inova Fairfax Hospital, Falls Church, VA
c Department of Medicine, Inova Fairfax Hospital, Falls Church, VA
d Department of Computational Sciences, George Mason University, Fairfax, VA
e Department of Neurosurgery, George Washington School of Medicine, Washington, DC
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FIG 1. Physiologic flow conditions derived from PC-MR measurements on a normal subject. A, MRA. B, Vessels of the circle of Willis and location of PC-MR section planes. C, Magnitude image of PC-MR measurement. D, Phase image of PC-MR measurement. E, Flow rate curve obtained from the PC-MR measurement on the right internal carotid artery.
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FIG 2. Construction of a patient-specific vascular CFD model. A, Original 3DRA image. B, Smoothed image. C, Segmented image. D, Initial vascular reconstruction. E, Vessel geometry after deformable model and interactive truncation of arterial branches. F, Finite element grid. G, Peak pressure distribution. H, Mean wall shear stress distribution. I, Definition of cut plane used to visualize velocity pattern. J–L, Intra-aneurysmal flow velocity on cut plane at different instants during the cardiac cycle.
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FIG 3. Examples of aneurysms where the inflow jet impacts the neck (A), the body (B), or the dome (C) or has a changing impingement region (D). Images, from left to right, present volume rendering of 3DRA image, reconstructed model, mean wall shear stress distribution, and intra-aneurysmal flow velocity on a planar cut through the sac at 4 instants during the cardiac cycle.
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FIG 4. Examples of aneurysms with inflow jet located in the distal (A) and proximal (B) region of the neck. Images, from left to right, present volume rendering of 3DRA image, reconstructed model, and intra-aneurysmal flow velocity on a planar cut through the sac at 3 instants during the cardiac cycle.
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FIG 5. Schematic drawings of the most prominent flow structures observed in small (left) and large (right) aneurysms with flow types I (top) through IV (bottom). Arrows indicate the direction of flow at 3 instants during the cardiac cycle and illustrate the complexity and stability of the intra-aneurysmal flow patterns for the 4 flow type categories.
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FIG 6. Examples of small and large impact zones. A and B, Ruptured aneurysms with small flow impingement regions. C and D, Unruptured aneurysms with large impact zones. Red arrows indicate the flow impingement region.
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