This thesis presents the design, implementation and testing of magnetic resonance imaging (MRI) sequences using spiral readout gradients. Three different designs and their corresponding sequences are developed: 14-interleaf, short readout, 4-interleaf, medium readout; and single-shot, long readout. The sequences are run in both 2D multislice and 3D modes. Image reconstruction is performed using regridding, together with three different spiral density compensation methods. / Results are compared for both phantom and in vivo human brain data. They indicate that the medium and long readout scans suffer from a certain level of image distortion due to field inhomogeneities, as well as T2* decay, in relation to their longer data acquisition times. This distortion is improved using a conjugate phase reconstruction technique, based on field maps generated from the same sequences. / Custom software was developed to design the spiral gradients, set-up the sequences and reconstruct images. This software is flexible, and can support a variety of scan parameters, taking into consideration the limitations of a given MRI scanner.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30258 |
| Date | January 2000 |
| Creators | Lazda, Andreas E. |
| Contributors | Pike, G. Bruce (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Biomedical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001740765, proquestno: MQ64234, Theses scanned by UMI/ProQuest. |
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