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2018_pahlavian_phd_Dissertation.pdf (37.43 MB)

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Non-Invasive Assessment of Cerebrospinal Fluid and Brain Tissue Biomechanics using MRI and Computational Modeling

Heidari Pahlavian, Soroush
http://rave.ohiolink.edu/etdc/view?acc_num=akron1522060187703491

Abstract Details

2018, Doctor of Philosophy, University of Akron, Mechanical Engineering.
Abnormal alterations in cerebrospinal fluid (CSF) flow and intrinsic cardiac-induced deformations of brain tissue are thought to play an important role in the pathophysiology of various neurological disorders. Using magnetic resonance imaging (MRI), numerical phantoms, and experimental platforms, we studied the feasibility and performance of multiple MRI techniques and numerical models to quantify CSF and neural tissues biomechanics. First, we evaluated the accuracy of time-resolved three directional phase contrast MRI (4D PCMRI) in quantifying CSF velocity and relative pressure using numerical and experimental phantoms. 4D PCMRI was shown to be accurate in measuring peak through-plane velocities. 4D PCMRI-derived CSF pressure gradients were markedly smaller than the reference solutions. However, these underestimations were consistent across different geometries and flow boundary conditions. Our results supported the use of 4D PCMRI to assess CSF velocities and showed the possible utility of this technique for comparison of pressure-based parameters between patients. Next, we assessed the impact of neural tissue motion on CSF dynamics using a moving boundary computational fluid dynamics simulation. A relatively small neural tissue motion (~150 to 300 µm) was found to increase peak CSF velocity and pressure dissociation across the craniovertebral junction by up to 60 and 120%, respectively. Finally, we examined the utility of displacement-encoding with stimulated echoes (DENSE) MRI in regional quantification of brain tissue motion and strain. Quantification of small neural tissue motion and strain and their regional variations was shown to be feasible using DENSE MRI. Medial and inferior brain structures had significantly larger motion and strain compared to those located more peripherally. Our results showed that DENSE MRI has the potential to be utilized as a tool to evaluate the changes in brain tissue dynamics resulting from alterations in biomechanical stresses and tissue properties. This dissertation research showed that the approaches combining engineering tools and MRI sequences could be helpful to develop MRI-derived parameters and biomarkers for improved assessment of neurological disorders. Based on these findings, future research should focus on the possible clinical utilities of the parameters described herein to quantify CSF hydrodynamics and brain tissue dynamics.
Francis Loth (Advisor)
230 p.
Biomedical Engineering; Biomedical Research; Mechanical Engineering; Medical Imaging
MRI, cerebrospinal fluid, phase contrast, tissue strain

Recommended Citations

Citations

  • Heidari Pahlavian, S. (2018). Non-Invasive Assessment of Cerebrospinal Fluid and Brain Tissue Biomechanics using MRI and Computational Modeling [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1522060187703491

    APA Style (7th edition)

  • Heidari Pahlavian, Soroush. Non-Invasive Assessment of Cerebrospinal Fluid and Brain Tissue Biomechanics using MRI and Computational Modeling. 2018. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1522060187703491.

    MLA Style (8th edition)

  • Heidari Pahlavian, Soroush. "Non-Invasive Assessment of Cerebrospinal Fluid and Brain Tissue Biomechanics using MRI and Computational Modeling." Doctoral dissertation, University of Akron, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1522060187703491

    Chicago Manual of Style (17th edition)

akron1522060187703491
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© 2018, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.