Author
Keerthivasan, Mahesh BharathIssue Date
2012Keywords
magnetic resonance elastographyAdvisor
Bilgin, Ali
Metadata
Show full item recordPublisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
Magnetic Resonance Elastography (MRE) is a non-invasive imaging technique used to determine the elastic properties of biological tissues. It can be used to aid the diagnosis of pathologies (such as tumors and fibrosis) which result in the variation of tissue stiffness. In this thesis, a MR elastography system was developed for use in a clinical setting. A pressure-based longitudinal driver was built to generate the shear waves. An elastography pulse sequence with motion encoding gradients was designed based on the gradient-echo and the spin-echo sequences. The pulse sequence included the ability to switch the motion encoding along any of the three coordinate axes depending on the direction of motion to be measured. Wave images were obtained by acquiring phase data for different time offsets in the motion cycle. An elastogram was computed from the phase data using the Local Frequency Estimation (LFE) algorithm. The validity of the method was experimentally verified using silicone and agar gel phantoms of varying stiffnesses. The performance of the gradient-echo and spin-echo sequences were investigated for different motion encoding gradient parameters.Type
textElectronic Thesis
Degree Name
M.S.Degree Level
mastersDegree Program
Graduate CollegeElectrical and Computer Engineering