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On the accuracy of viscous and turbulent loss quantification in stenotic aortic flow using phase‐contrast MRI
Author(s) -
Binter Christian,
Gülan Utku,
Holzner Markus,
Kozerke Sebastian
Publication year - 2016
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25862
Subject(s) - laminar flow , voxel , turbulence , turbulence kinetic energy , imaging phantom , noise (video) , sensitivity (control systems) , physics , mechanics , nuclear magnetic resonance , materials science , optics , medicine , radiology , artificial intelligence , electronic engineering , computer science , image (mathematics) , engineering
Purpose To investigate the limits of phase contrast MRI (PC‐MRI)–based measurements of viscous losses and turbulent kinetic energy (TKE) pertaining to spatial resolution, signal‐to‐noise ratio (SNR), and non‐Gaussian intravoxel velocity distributions. Theory and Methods High‐resolution particle tracking velocimetry data obtained in a realistic aortic phantom with stenotic flow were used to simulate PC‐MRI measurements at different resolutions and noise levels. Laminar viscous losses were computed using the spatial gradients of the mean velocity vector field, and TKE levels were derived based on the intravoxel phase dispersion of flow‐sensitized PC‐MRI measurements. Results Increasing the voxel size from 0.625 to 2.5 mm resulted in an underestimation of viscous losses of up to 83%, whereas total TKE values showed errors of <15% and reduced sensitivity to voxel size. Relative errors in viscous loss quantification were found to be less dependent on noise levels when compared with TKE values. In general, a SNR of 20–30 is required for both methods. Conclusion At spatial resolutions feasible in clinical three‐dimensional PC‐MRI measurements, viscous losses of stenotic flows are significantly underestimated, whereas TKE shows smaller errors and reduced sensitivity to spatial resolution. Magn Reson Med 76:191–196, 2016. © 2015 Wiley Periodicals, Inc.