Assessment of 3D velocity vector fields and turbulent kinetic energy in a realistic aortic phantom using multi-point variable-density velocity encoding
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KeywordsAortic Arch Turbulent Kinetic Energy Particle Tracking Velocimetry Velocity Vector Field Mechanical Aortic Valve
A multi-point velocity encoding approach for the assessment of velocity vector fields and TKE is shown in this work. The method is applied in an aortic arch phantom under different flow conditions.
Three-dimensional Phase Contrast (PC) MRI has emerged as a promising non-invasive acquisition technique for assessing velocity vector fields of blood flow . To address the limited sensitivity when velocities are much lower than the encoding velocity venc, three-point acquisition methods with a high venc and a low venc acquisition to unwrap the low venc scan may be employed . However, by using the high venc data only to control phase unaliasing the approaches are not signal-to-noise ratio (SNR) efficient. This fact becomes relevant in particular when incorporating data undersampling techniques to shorten the long scan times associated with 3D PC-MRI. Accordingly, SNR optimality of encoding and decoding is desired. To this end Bayes’ approaches have been proposed and adapted to PC-MRI [3, 4].
In the present work the feasibility of velocity vector field and turbulent kinetic energy (TKE) mapping based on multi-point variable-density velocity encoding with spatiotemporal undersampling is demonstrated on a realistic aortic phantom .
The presented work shows the assessment of velocity vector fields and TKE in a realistic aortic phantom. Using the identical setup comparison of TKE values to data from Particle Tracking Velocimetry (PTV) is possible hence permitting assessment relative to a method of reference for measuring fluctuating velocities at very high temporal resolution.
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