Comparison of blood viscosity models in different degrees of carotid artery stenosis

This study systematically quantified the discrepancies between Newtonian and non-Newtonian blood viscosity models in predicting hemodynamic parameters across different degrees of carotid artery stenosis. Statistical analyses revealed significant differences between the two models in WSS, TAWSS, OSI, and RRT (<i>p</i> < 0.001 for all parameters). Newtonian models, while computationally efficient, overestimated TAWSS, OSI, and RRT while underestimating WSS, particularly in moderate to severe stenosis. In contrast, non-Newtonian models provided more physiologically accurate predictions, especially in regions with high shear stress variations. The results emphasize the importance of selecting appropriate viscosity models for CFD-based patient-specific risk assessment, particularly in stroke prediction, plaque evaluation, and surgical planning. Non-Newtonian models should be prioritized in high-risk patients where flow disturbances are more pronounced, whereas Newtonian models remain suitable for early screening and rapid assessments.