In most simulations of intracranial aneurysm hemodynamics, blood is assumed to be a Newtonian fluid. However, it is a non-Newtonian fluid, and its viscosity profile differs among individuals. Therefore, the common viscosity assumption may not be valid for all patients.
This study aims to test the suitability of the common viscosity assumption.
Blood viscosity datasets were obtained from two healthy volunteers. Three simulations were performed for three different-sized aneurysms, two using measured value-based non-Newtonian models and one using a Newtonian model. The parameters proposed to predict an aneurysmal rupture obtained using the non-Newtonian models were compared with those obtained using the Newtonian model.
The largest difference (25%) in the normalized wall shear stress (NWSS) was observed in the smallest aneurysm. Comparing the difference ratio to the NWSS with the Newtonian model between the two Non-Newtonian models, the difference of the ratio was 17.3%.
Irrespective of the aneurysmal size, computational fluid dynamics simulations with either the common Newtonian or non-Newtonian viscosity assumption could lead to values different from those of the patient-specific viscosity model for hemodynamic parameters such as NWSS.
UCAS Japan Investigators. The Natural Course of Unruptured Cerebral Aneurysms in a Japanese Cohort. N Engl J Med. 2012; 366(26): 2474-82.
Shojima M, , Oshima M, , Takagi K, , Torii R, , Hayakawa M, , Katada K, et al. Magnitude and Role of Wall Shear Stress on Cerebral Aneurysm: Computational Fluid Dynamic Study of 20 Middle Cerebral Artery Aneurysms. Stroke. 2004; 35(11): 2500-5.
Castro MA, , Putman CM, , Sheridan MJ, , Cebral JR. Hemodynamic patterns of anterior communicating artery aneurysms: A possible association with rupture. AJNR Am J Neuroradiol. 2009; 30(2): 297-302.
Castro M, , Putman C, , Radaelli A, , Frangi A, , Cebral J. Hemodynamics and Rupture of Terminal Cerebral Aneurysms. Acad Radiol. 2009; 16(10): 1201-7.
Cebral JR, , Mut F, , Weir J, , Putman C. Quantitative characterization of the hemodynamic environment in ruptured and unruptured brain aneurysms. AJNR Am J Neuroradiol. 2011; 32(1): 145-51.
Xiang J, , Natarajan SK, , Tremmel M, , Ma D, , Mocco J, , Hopkins LN, et al. Hemodynamic-morphologic discriminants for intracranial aneurysm rupture. Stroke. 2011; 42(1): 144-52.
Qian Y, , Takao H, , Umezu M, , Murayama Y. Risk analysis of unruptured aneurysms using computational fluid dynamics technology: preliminary results. AJNR Am J Neuroradiol. 2011; 32(10): 1948-55.
Lu G, , Huang L, , Zhang XL, , Wang SZ, , Hong Y, , Hu Z, et al. Influence of hemodynamic factors on rupture of intracranial aneurysms: patient-specific 3D mirror aneurysms model computational fluid dynamics simulation. AJNR Am J Neuroradiol. 2011; 32(7): 1255-61.
Takao H, , Murayama Y, , Otsuka S, , Qian Y, , Mohamed A, , Masuda S, et al. Hemodynamic differences between unruptured and ruptured intracranial aneurysms during observation. Stroke. 2012; 43(5): 1436-9.
Miura Y, , Ishida F, , Umeda Y, , Tanemura H, , Suzuki H, , Matsushima S, et al. Low wall shear stress is independently associated with the rupture status of middle cerebral artery aneurysms. Stroke. 2013; 44(2): 519-21.
Meng H, , Tutino VM, , Xiang J, , Siddiqui A. High WSS or Low WSS? Complex interactions of hemodynamics with intracranial aneurysm initiation, growth, and rupture: Toward a unifying hypothesis. AJNR Am J Neuroradiol. 2014; 35(7): 1254-62.
Morales HG, , Larrabide I, , Geers AJ, , Aguilar ML, , Frangi AF. Newtonian and non-Newtonian blood flow in coiled cerebral aneurysms. J Biomech. 2013; 46(13): 2158-64.
Yamamoto H, , Kawamura K, , Omura K, , Tokudome S. Development of a compact-sized falling needle rheometer for measurement of flow properties of fresh human blood. Int J Thermophys. 2010; 31(11): 2361-79.
Gijsen FJ, , van de Vosse FN, , Janssen JD. The influence of the non-Newtonian properties of blood on the flow in large arteries: steady flow in a carotid bifurcation model. J Biomech. 1999; 32(6): 601-8.
Cebral JR, , Castro MA, , Appanaboyina S, , Putman CM, , Millan D, , Frangi AF. Efficient pipeline for image-based patient-specific analysis of cerebral aneurysm hemodynamics: technique and sensitivity. IEEE Trans Med Imaging. 2005; 24(4): 457-67.
Valencia AA, , Guzmán AM, , Finol EA, , Amon CH. Blood flow dynamics in saccular aneurysm models of the basilar artery. J Biomech Eng. 2006; 128(4): 516-26.
Fisher C, , Rossmann JS. Effect of non-newtonian behavior on hemodynamics of cerebral aneurysms. J Biomech Eng. 2009; 131(9): 091004.
Xiang J, , Tremmel M, , Kolega J, , Levy EI, , Natarajan SK, , Meng H. Newtonian viscosity model could overestimate wall shear stress in intracranial aneurysm domes and underestimate rupture risk. J Neurointerv Surg. 2012; 4(5): 351-7.
Evju Ø, , Valen-Sendstad K, , Mardal K-A. A study of wall shear stress in 12 aneurysms with respect to different viscosity models and flow conditions. J Biomech. 2013; 46(16): 2802-8.
Hippelheuser JE, , Lauric A, , Cohen AD, , Malek AM. Realistic non-Newtonian viscosity modeling highlights hemodynamic differences between intracranial aneurysms with and without surface blebs. J Biomech. 2014; 47(15): 3695-703.
Ford MD, , Alperin N, , Lee SH, , Holdsworth DW, , Steinman DA. Characterization of volumetric flow rate waveforms in the normal internal carotid and vertebral arteries. Physiol Meas. 2005; 26(4): 477-88.
Venkatesan J, , Sankar DS, , Hemalatha K, , Yatim Y. Mathematical analysis of Casson fluid model for blood rheology in stenosed narrow arteries. J Appl Math. 2013: 2013. Available from: http://dx.doi.org/10.1155/2013/583809.
Cebral JR, , Castro MA, , Appanaboyina S, , Putman CM, , Millan D, , Frangi AF. Efficient pipeline for image-based patient-specific analysis of cerebral aneurysm hemodynamics: Technique and sensitivity. IEEE Trans Med Imaging. 2005; 24(4): 457-67.
Suzuki T, , Yamamoto H, , Kawamura K, et al. Automatic flow analysis for human blood at low shear rate range. In: Proceedings of the 6th International Multi-Conference on Engineering and Technological Innovation, Orlando, Florida. 9-12 July 2013. Available from: http://www.iiis.org/CDs2013/CD2013SCI/IMETI_2013/PapersPdf/FA841NM.pdf
Zhang Y, , Takao H, , Murayama Y, , Qian Y. Propose a wall shear stress divergence to estimate the risks of intracranial aneurysm rupture. ScientificWorldJournal. Jan 2013; 2013: 508131. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3804446/.
Jing L, , Fan J, , Wang Y, , Li H, , Wang S, , Yang X, et al. Morphologic and Hemodynamic Analysis in the Patients with Multiple Intracranial Aneurysms: Ruptured versus Unruptured. PLoS One. 2015; 10(7): e0132494. Available from: http://dx.plos. org/10.1371/journal. pone.0132494.
Xiang J, , Tutino VM, , Snyder KV, , Meng H. CFD: Computational Fluid Dynamics or Confounding Factor Dissemination? The Role of Hemodynamics in Intracranial Aneurysm Rupture Risk Assessment. AJNR Am J Neuroradiol. 2014; 35(10): 1849-57.