Direct Quantification of Turbulent Shear Stresses by Multi-Point Phase-Contrast MRI

Christian Binter¹, Verena Knobloch¹, Andreas Sigfridsson¹, Sebastian Kozerke¹

Excessive shear stresses in pathological flow situations can lead to platelet activation and damage of red blood cells. In-vivo assessment of shear stresses has, however, been impractical. In the present work it is demonstrated that turbulent shear stresses can be determined non-invasively using generalized phase-contrast MRI. Multi-point velocity encoding is employed to obtain information about velocity fluctuations along multiple directions, which permits quantification of turbulent kinetic energy and turbulent shear stresses. Measurements of artificial aortic valves in phantoms and in volunteers demonstrate the feasibility of the method in-vitro and in-vivo.