Portable low-cost magnetic resonance imaging
Name
899994806-MIT.pdf
Description
Full printable version
Size
23.28 MB
Format
Adobe PDF
Checksum (MD5)
50174594af2ee4e76f73ec8b1ba42926
Author(s)
Cooley, Clarissa Zimmerman
Advisor(s)
Lawrence L. Wald.
Date Issued
2014
Publisher
Massachusetts Institute of Technology
Abstract
Purpose: 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.
Description
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 143-153).
Subjects
Electrical Engineering and Computer Science.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Terms of Use
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