Computational approach to quantifying hemodynamic forces in giant cerebral aneurysms.
OBJECTIVE
The options for treating giant fusiform basilar aneurysms are limited, and the potential impact of planned interventions is difficult to assess. We developed a computational framework to evaluate the impact that interventions might have on hemodynamic conditions.


METHODS
A computational fluid dynamics approach was used to determine the velocity field, wall shear stress, and pressure distribution within a model of a basilar artery before and after a simulated occlusion of one vertebral artery. The vascular geometry in a patient with a giant fusiform basilar artery aneurysm was determined by using contrast-enhanced MR angiography, and the numerical simulation approach was used to calculate the flow fields in the presenting geometry and to predict the flow field that would occur if a vertebral artery were occluded.


RESULTS
In the model geometry, computational fluid dynamics indicated that there would be a symmetric flow pattern with a strong central stream and large recirculation zones at the walls. After simulated occlusion of one vertebral artery, the primary stream was diverted to one side, resulting in high pressure and increased wall shear stress. For the patient-specific geometry, flow patterns were shown to depend strongly on how much flow there was in each vertebral artery.


CONCLUSIONS
Contrast-enhanced MR angiography is an effective tool for demonstrating the luminal boundaries of large intracranial aneurysms. Computational fluid dynamics is a powerful tool for determining the prevailing flow conditions in vascular territories and for modeling the possible alterations of the flow field that would result from interventional treatments.
Jou
Liang-Der
LD
Department of Radiology, VA Medical Center and University of California San Francisco, USA.
Quick
Christopher M
CM
Young
William L
WL
Lawton
Michael T
MT
Higashida
Randall
R
Martin
Alastair
A
Saloner
David
D
D001488:Basilar Artery / Q000473:pathology / Q000503:physiopathology; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003198:Computer Simulation; D003251:Constriction, Pathologic; D003287:Contrast Media; D005290:Ferric Compounds; D018056:Hemorheology; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000503:physiopathology*; D007501:Iron; D018810:Magnetic Resonance Angiography; D010087:Oxides; D013314:Stress, Mechanical; D014711:Vertebral Artery / Q000473:pathology / Q000503:physiopathology
D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron