Cardiovascular ischemic diseases, such as myocardial infarction and stroke, are the leading causes of death and
disability worldwide. Atherosclerotic plaque is one of the main reasons for such ischemic events. Major systemic
atherosclerotic risk factors, such as hypertension, smoking, hyperlipidemia, diabetes mellitus and a sedentary lifestyle, fail
to explain the focal nature of atheroma. Local hemodynamic conditions are thought to be closely associated with such a
phenomenon. Shear stress has been widely accepted as an important factor in the development of atherosclerosis plaques.
Recent advances in medical imaging and computational modeling techniques have enabled patients-specific
hemodynamics to be visualized in vivo. Shear stress can be computed using direct flow imaging techniques, such as
Doppler ultrasound and phase-contrast magnetic resonance imaging (PC-MRI), or image-based computational fluid
dynamics (CFD) simulations. Due to the important role of geometry in determining local flow patterns, it is also relevant
to study geometric risk factors, which could potentially be used as a surrogate for hemodynamic conditions, to avoid
expensive flow imaging and computations. This patent review focuses on: (1) current approaches of in vivo quantification
of patient-specific shear stress conditions, including both direct flow imaging techniques and image-based CFD
simulations; and (2) clinical evidence of shear stress conditions and geometric risk factors in the development of
Atherosclerosis, computational fluid dynamics (CFD), flow imaging, geometry, plaque, shear stress.
University Department of Radiology, Box 218, Cambridge University Hospitals Foundation Trust, Cambridge CB2 0QQ, UK.