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Bayesian Models for Practical Flow Imaging Using Phase Contrast Magnetic Resonance Imaging

Rich, Adam V
http://orcid.org/0000-0003-2331-0370
http://rave.ohiolink.edu/etdc/view?acc_num=osu1490987092511083

Abstract Details

2017, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
Since the digital revolution, our fascination with detail is endless. High definition images and video have become standard. Televisions and cellphones with screens containing 2-10 million pixels are commonplace. The field of magnetic resonance imaging (MRI) is no different. In MRI, doctors push for higher spatial and temporal resolution images, with current brain imaging having sub mm pixel resolution. However, acquisition time for MRI is proportional to the number of pixels in the image. Therefore, high resolution images can have unreasonably long scan times that reduce patient comfort and increase costs. Phase contrast MRI (PC-MRI) encodes velocity information into the phase of the complex valued MR image. Multiple encoded images are required to recover the velocity information, further increasing scan duration. However, due to the redundant nature of the data collection, it is possible to apply regularizing constraints to aid in the inversion of velocity maps. In this work we propose Bayesian imaging techniques to accelerate acquisition of PC-MRI data. The proposed techniques exploit structure across velocity encoded images via a mixture density prior that applies different regularization based on the presence of velocity within the image. Structure across space and time is exploited using non-decimated wavelet transforms. Using these prior-densities, we form a Bayesian data model and an associated factor graph of the posterior distribution. Through a combination of standard and loopy belief propagation, iterative inversion algorithms are derived. Computation on the loopy sections of the graph is greatly accelerated through the use of generalized approximate message passing. For 2D through-plane flow, the Bayesian techniques outperform prior art in terms of normalized mean squared error and flow quantification, e.g. stroke volume and peak velocity. In addition, the proposed technique enables image collection accelerated by a factor of 10 while preserving flow quantification. In real-time imaging, we demonstrate the feasibility of through-plane PC-MRI. For 4D flow MRI, the proposed technique enables rate 20 acceleration in a flow phantom. Finally, we demonstrate the first single breath-hold, cardiac 4D flow PC-MRI acquisition in vivo.
Lee Potter (Advisor)
Rizwan Ahmad (Committee Member)
Orlando Simonetti (Committee Member)
162 p.
Electrical Engineering; Medical Imaging

Recommended Citations

Citations

  • Rich, A. V. (2017). Bayesian Models for Practical Flow Imaging Using Phase Contrast Magnetic Resonance Imaging [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1490987092511083

    APA Style (7th edition)

  • Rich, Adam. Bayesian Models for Practical Flow Imaging Using Phase Contrast Magnetic Resonance Imaging. 2017. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1490987092511083.

    MLA Style (8th edition)

  • Rich, Adam. "Bayesian Models for Practical Flow Imaging Using Phase Contrast Magnetic Resonance Imaging." Doctoral dissertation, Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1490987092511083

    Chicago Manual of Style (17th edition)

osu1490987092511083
515
© 2017, some rights reserved.Creative Commons License Bayesian Models for Practical Flow Imaging Using Phase Contrast Magnetic Resonance Imaging by Adam V Rich is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by The Ohio State University and OhioLINK.