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dc.contributor.advisorLawrence L. Wald.en_US
dc.contributor.authorCooley, Clarissa Zimmermanen_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.en_US
dc.date.accessioned2015-01-20T17:58:55Z
dc.date.available2015-01-20T17:58:55Z
dc.date.copyright2014en_US
dc.date.issued2014en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/93060
dc.descriptionThesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (pages 143-153).en_US
dc.description.abstractPurpose: As the premiere modality for brain imaging, MRI could find wider applicability if lightweight, portable systems were available for siting in unconventional locations such as intensive care units (ICUs), physician offices, surgical suites, ambulances, emergency rooms, sports facilities, or rural healthcare sites. Methods: A truly portable (<100kg) proof-of-concept MRI scanner has been constructed and validated, which replaces conventional gradient encoding with a rotating lightweight, cryogen-free, low-field magnet. When rotated about the object, an inhomogeneous magnetic field pattern is used as a rotating Spatial Encoding Magnetic field (rSEM) to create generalized projections and encode the iteratively reconstructed 2D images. Multiple receive channels are used to disambiguate the non-bijective encoding field. Results: The system is validated with experimental images of 2D test phantoms. Similar to other non-linear field encoding schemes, the spatial resolution is position dependent with blurring in the center, but this will be improved with modifications to the magnet design. Conclusion: This novel MRI scanner demonstrates the potential for portability by simultaneously relaxing the magnet homogeneity criteria and eliminating gradient coils. This new architecture and encoding scheme shows convincing proof of concept images that are expected to be further improved with refinement of the calibration and methodology.en_US
dc.description.statementofresponsibilityby Clarissa Zimmerman Cooley.en_US
dc.format.extent153 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectElectrical Engineering and Computer Science.en_US
dc.titlePortable low-cost magnetic resonance imagingen_US
dc.typeThesisen_US
dc.description.degreePh. D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
dc.identifier.oclc899994806en_US


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