PT  - JOURNAL ARTICLE
AU  - Cebral, J.R.
AU  - Mut, F.
AU  - Weir, J.
AU  - Putman, C.
TI  - Quantitative Characterization of the Hemodynamic Environment in Ruptured and Unruptured Brain Aneurysms
AID  - 10.3174/ajnr.A2419
DP  - 2011 Jan 01
TA  - American Journal of Neuroradiology
PG  - 145--151
VI  - 32
IP  - 1
4099  - http://www.ajnr.org/content/32/1/145.short
4100  - http://www.ajnr.org/content/32/1/145.full
SO  - Am. J. Neuroradiol.2011 Jan 01; 32
AB  - BACKGROUND AND PURPOSE: Hemodynamics are thought to play an important role in the mechanisms of aneurysm pathogenesis, progression, and rupture. The purpose of this study was to define quantitative measures related to qualitative flow characteristics previously analyzed and to investigate their relationship to aneurysm rupture. MATERIALS AND METHODS: The hemodynamic environments in 210 cerebral aneurysms were analyzed by using image-based CFD under different flow conditions. Quantitative hemodynamic variables were defined and extracted from the simulation results. A statistical analysis of the relationship to the previous history of aneurysm rupture was performed, and the variability with flow conditions was assessed. RESULTS: Ruptured aneurysms were more likely to have larger inflow concentrations, larger MWSS, larger shear concentrations, and lower viscous dissipation ratios than unruptured aneurysms. Areas under low WSS and measures of abnormally low shear force distributions of ruptured and unruptured aneurysms were not statistically different. Although the values of hemodynamic quantities changed with different flow conditions, the statistical differences or ratios between their mean values over the ruptured and unruptured groups were maintained, for both pulsatile and steady flows. CONCLUSIONS: Concentrated inflow streams and WSS distributions with elevated levels of MWSS and low aneurysmal viscous dissipation are statistically associated with a clinical history of prior aneurysm rupture. In contrast, the area and total viscous shear force applied in the aneurysm region subjected to abnormally low WSS levels are not. This study highlights the potential for image-based CFD for investigating aneurysm-evolution mechanisms and for clinical assessment of aneurysm risks. bpmbeats per minuteCFDcomputational fluid dynamics3DRA3D rotational angiographyHRheart rateICIinflow concentration indexKERkinetic energy ratioLSAlow shear areaLSIlow shear indexMWSSmaximum WSSSCIshear concentration indexVDRviscous dissipation ratioWSSwall shear stress