Author ORCID Identifier

https://orcid.org/0000-0002-7955-2224

Defense Date

2021

Document Type

Thesis

Degree Name

Master of Science

Department

Biomedical Engineering

First Advisor

John Wilson, MD PhD

Second Advisor

Jennifer Jordan, PhD

Third Advisor

Uyen Truong, MD

Abstract

Unstable aortic aneurysms and dissections are serious cardiovascular conditions associated with high mortality. The current gold standards for assessment of stability, however, rely on simple geometric measurements, like cross-sectional area or increased diameter between follow-up scans, and fail to incorporate information about underlying aortic mechanics. Displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) has been used previously to determine heterogeneous circumferential strain patterns in the aortas of healthy volunteers. Here, I introduce technical improvements to DENSE aortic analysis and early pilot application in patients at higher risk for the development of aortopathies. Modifications to the DENSE aortic postprocessing method involving the separate spatial smoothing of the inner and outer layers of the aortic wall allowed for the preservation of radial and shear strains without impacting circumferential strain calculations. The implementation of a semiautomatic segmentation approach utilizing the intrinsic kinematic information provided by DENSE MRI reduced lengthy post-processing times while generating circumferential strain distributions with good agreement to a manually generated benchmark. Finally, a new analysis pipeline for the combined use and spatial correlation of 4D phase-contrast MRI alongside DENSE MRI to quantify both regional fluid and solid mechanics in the descending aorta is explored in a limited pilot study.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-13-2021

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