4D Flow MRI Pressure Estimation Using Velocity Measurement-Error-Based Weighted Least-Squares
| Autor: | David Saloner, Pavlos P. Vlachos, Susanne Schnell, Jiacheng Zhang, Sean Rothenberger, Melissa C. Brindise, Vitaliy L. Rayz, Michael Markl |
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| Rok vydání: | 2020 |
| Předmět: |
Flow measurement
030218 nuclear medicine & medical imaging law.invention Physics::Fluid Dynamics Motion 03 medical and health sciences 0302 clinical medicine Particle tracking velocimetry Incompressible flow law Humans Least-Squares Analysis Electrical and Electronic Engineering Pressure gradient Physics Radiological and Ultrasound Technology Mathematical analysis Reproducibility of Results Hagen–Poiseuille equation Magnetic Resonance Imaging Computer Science Applications Pressure measurement Flow (mathematics) Poisson's equation Algorithms Blood Flow Velocity Software |
| Zdroj: | IEEE Transactions on Medical Imaging. 39:1668-1680 |
| ISSN: | 1558-254X 0278-0062 |
| Popis: | This work introduces a 4D flow magnetic resonance imaging (MRI) pressure reconstruction method which employs weighted least-squares (WLS) for pressure integration. Pressure gradients are calculated from the velocity fields, and velocity errors are estimated from the velocity divergence for incompressible flow. Pressure gradient errors are estimated by propagating the velocity errors through Navier-Stokes momentum equation. A weight matrix is generated based on the pressure gradient errors, then employed for pressure reconstruction. The pressure reconstruction method was demonstrated and analyzed using synthetic velocity fields as well as Poiseuille flow measured using in vitro 4D flow MRI. Performance of the proposed WLS method was compared to the method of solving the pressure Poisson equation which has been the primary method used in the previous studies. Error analysis indicated that the proposed method is more robust to velocity measurement errors. Improvement on pressure results was found to be more significant for the cases with spatially-varying velocity error level, with reductions in error ranging from 50% to over 200%. Finally, the method was applied to flow in patient-specific cerebral aneurysms. Validation was performed with in vitro flow data collected using Particle Tracking Velocimetry (PTV) and in vivo flow measurement obtained using 4D flow MRI. Pressure calculated by WLS, as opposed to the Poisson equation, was more consistent with the flow structures and showed better agreement between the in vivo and in vitro data. These results suggest the utility of WLS method to obtain reliable pressure field from clinical flow measurement data. |
| Databáze: | OpenAIRE |
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