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Richard J. Gilbert. Liang, Jason (Jason G.) Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2006-05-15T20:41:10Z 2006-05-15T20:41:10Z 2005 2005 http://hdl.handle.net/1721.1/32947 62785385 Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005. Includes bibliographical references (leaves 33-36). The ability to resolve complex myofiber populations is important for relating architectural structure with mechanical unction in muscular tissues. To address this issue, we sought to validate the capacity of Diffusion Spectrum Imaging (DSI), an MRI method for assessing molecular diffusion in a confined geometry, to determine fiber alignment in tissues whose myofibers are aligned at varying orientations. By this method, molecular displacement in a tissue can be determined by Fourier transforming the echo intensity against gradient strength at fixed gradient pulse spacing. The displacement profiles are visualized by graphing 3D isocontour icons for each voxel, with the isocontour shape and size representing the magnitude and direction of the constituting fiber populations. Validation of DSI was accomplished with two sets of experiments: We simulated diffusive motion and a DSI experiment within the constraints of crossing fibers, and determined that DSI accurately depicts arbitrary angular relationships between crossing fibers. We also used DSI to accurately resolve the geometry of aligned channels in poly(dimethylsiloxane) (PDMS) microfluidic phantoms. by Jason Liang. S.B. 36 leavves 1847912 bytes 1847288 bytes application/pdf application/pdf eng Massachusetts Institute of Technology M.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. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Mapping crossing myofiber populations with Diffusion Spectrum Imaging in simulated and microfabricated model tissues Thesis application/pdf Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="d53e32df-627d-4495-9f19-7b0b5c12bc2f"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Mapping crossing myofiber populations with Diffusion Spectrum Imaging in simulated and microfabricated model tissues</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2005</PublicationDate> <Authors> <Author> <DisplayName>Liang, Jason (Jason G.)</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>The ability to resolve complex myofiber populations is important for relating architectural structure with mechanical unction in muscular tissues. To address this issue, we sought to validate the capacity of Diffusion Spectrum Imaging (DSI), an MRI method for assessing molecular diffusion in a confined geometry, to determine fiber alignment in tissues whose myofibers are aligned at varying orientations. By this method, molecular displacement in a tissue can be determined by Fourier transforming the echo intensity against gradient strength at fixed gradient pulse spacing. The displacement profiles are visualized by graphing 3D isocontour icons for each voxel, with the isocontour shape and size representing the magnitude and direction of the constituting fiber populations. Validation of DSI was accomplished with two sets of experiments: We simulated diffusive motion and a DSI experiment within the constraints of crossing fibers, and determined that DSI accurately depicts arbitrary angular relationships between crossing fibers. We also used DSI to accurately resolve the geometry of aligned channels in poly(dimethylsiloxane) (PDMS) microfluidic phantoms.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>