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4D Flow MRI‐based pressure loss estimation in stenotic flows: Evaluation using numerical simulations
Author(s) -
Casas Belen,
Lantz Jonas,
Dyverfeldt Petter,
Ebbers Tino
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.25772
Subject(s) - bernoulli's principle , dissipation , mechanics , computational fluid dynamics , flow (mathematics) , physics , pressure gradient , rotational symmetry , mathematics , thermodynamics
Purpose To assess how 4D flow MRI‐based pressure and energy loss estimates correspond to net transstenotic pressure gradients (TPG net ) and their dependence on spatial resolution. Methods Numerical velocity data of stenotic flow were obtained from computational fluid dynamics (CFD) simulations in geometries with varying stenosis degrees, poststenotic diameters and flow rates. MRI measurements were simulated at different spatial resolutions. The simplified and extended Bernoulli equations, Pressure‐Poisson equation (PPE), and integration of turbulent kinetic energy (TKE) and viscous dissipation were compared against the true TPG net . Results The simplified Bernoulli equation overestimated the true TPG net (8.74 ± 0.67 versus 6.76 ± 0.54 mmHg). The extended Bernoulli equation performed better (6.57 ± 0.53 mmHg), although errors remained at low TPG net . TPG net estimations using the PPE were always close to zero. Total TKE and viscous dissipation correlated strongly with TPG net for each geometry (r 2 > 0.93) and moderately considering all geometries (r 2 = 0.756 and r 2 = 0.776, respectively). TKE estimates were accurate and minorly impacted by resolution. Viscous dissipation was overall underestimated and resolution dependent. Conclusion Several parameters overestimate or are not linearly related to TPG net and/or depend on spatial resolution. Considering idealized axisymmetric geometries and in absence of noise, TPG net was best estimated using the extended Bernoulli equation. Magn Reson Med 75:1808–1821, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance.