Carotid Phase-Contrast Magnetic Resonance before Treatment: 4D-Flow versus Standard 2D Imaging

The purpose of this study was to evaluate the level of agreement between flow/velocity data obtained from 2D-phase-contrast (PC) and 4D-flow in patients scheduled for treatment of carotid artery stenosis. Image acquisition was performed using a 1.5 T scanner. We compared mean flow rates, vessel areas, and peak velocities obtained during the acquisition with both techniques in 20 consecutive patients, 15 males and 5 females aged 69 ± 5 years (mean ± standard deviation). There was a good correlation between both techniques for the CCA flow (r = 0.65, p < 0.001), whereas for the ICA flow and ECA flow the correlation was only moderate (r = 0.4, p = 0.011 and r = 0.45, p = 0.003, respectively). Correlations of peak velocities between methods were good for CCA (r = 0.56, p < 0.001) and moderate for ECA (r = 0.41, p = 0.008). There was no correlation for ICA (r = 0.04, p = 0.805). Cross-sectional area values between methods showed no significant correlations for CCA (r = 0.18, p = 0.269), ICA (r = 0.1, p = 0.543), and ECA (r = 0.05, p = 0.767). Conclusion: the 4D-flow imaging provided a good correlation of CCA and a moderate correlation of ICA flow rates against 2D-PC, underestimating peak velocities and overestimating cross-sectional areas in all carotid segments.

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In Vitro Evaluation of Cerebrospinal Fluid Velocity Measurement Agreement, Reliability, and Reproducibility in Type I Chiari Malformation Using 2D Phase Contrast Magnetic Resonance Imaging and 4D Flow Imaging

10.21203/rs.3.rs-109548/v1 ◽

2020 ◽

Author(s):

Gwendolyn Williams ◽

Suraj Thyagaraj ◽

Audrey Fu ◽

John Oshinski ◽

Daniel Giese ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Chiari Malformation ◽

Phase Contrast ◽

Resonance Imaging ◽

4D Flow ◽

Csf Dynamics ◽

Contrast Magnetic Resonance ◽

Repeatability And Reproducibility ◽

Flow Techniques

Abstract Background Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed. Methods An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. Results Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ± 2 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). Conclusion Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.

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Numerical simulation of time-resolved 3D phase-contrast magnetic resonance imaging

PLoS ONE ◽

10.1371/journal.pone.0248816 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0248816

Author(s):

Thomas Puiseux ◽

Anou Sewonu ◽

Ramiro Moreno ◽

Simon Mendez ◽

Franck Nicoud

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Phase Contrast ◽

Navier Stokes ◽

Resonance Imaging ◽

4D Flow Mri ◽

4D Flow ◽

Time Resolved ◽

Contrast Magnetic Resonance ◽

Flow Mri

A numerical approach is presented to efficiently simulate time-resolved 3D phase-contrast Magnetic resonance Imaging (or 4D Flow MRI) acquisitions under realistic flow conditions. The Navier-Stokes and Bloch equations are simultaneously solved with an Eulerian-Lagrangian formalism. A semi-analytic solution for the Bloch equations as well as a periodic particle seeding strategy are developed to reduce the computational cost. The velocity reconstruction pipeline is first validated by considering a Poiseuille flow configuration. The 4D Flow MRI simulation procedure is then applied to the flow within an in vitro flow phantom typical of the cardiovascular system. The simulated MR velocity images compare favorably to both the flow computed by solving the Navier-Stokes equations and experimental 4D Flow MRI measurements. A practical application is finally presented in which the MRI simulation framework is used to identify the origins of the MRI measurement errors.

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In Vitro Evaluation of Cerebrospinal Fluid Velocity Measurement Agreement, Reliability, and Reproducibility in Type I Chiari Malformation Using 2D Phase Contrast Magnetic Resonance Imaging and 4D Flow Imaging

10.21203/rs.3.rs-109548/v2 ◽

2021 ◽

Author(s):

Gwendolyn Williams ◽

Suraj Thyagaraj ◽

Audrey Fu ◽

John Oshinski ◽

Daniel Giese ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Chiari Malformation ◽

Phase Contrast ◽

Resonance Imaging ◽

4D Flow ◽

Csf Dynamics ◽

Contrast Magnetic Resonance ◽

Repeatability And Reproducibility ◽

Flow Techniques

Abstract Background: Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed.Methods: An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. Results: Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ±1.5 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). Conclusion: Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.

Download Full-text