Magnetic Resonance Elastography is a method of imaging the elasticity of soft tissues through measurement of small motions induced into a sample. It shows great promise in the detection of a wide variety of pathologies, especially tumours. An imaging protocol was developed to acquire MR elastography data for use in a clinical setting. A 3D gradient echo sequence was modified to allow for the detection of harmonic motion and tested on silicone phantoms and ex-vivo muscle and brain samples. The time for acquiring a high resolution, quantitative dataset of 3D motions was about 45 minutes. Our imaging method included motion encoding along all three coordinate axes and at several time points along the motion cycle. This time could be easily be reduced by more than half for future clinical use, while still retaining full quantitative data. A modified EPI sequence shows promise for even faster acquisition. The ability to detect the mechanical anisotropy of brain and muscle tissue in ex-vivo samples was also investigated. Initial results from the muscle data indicate a change in shear wavelength is observed for actuation along orthogonal axes. This is a strong indicator of anisotropy detection. Further work needs to be done to improve results from the brain sample as preliminary results are inconclusive.
| Identifer | oai:union.ndltd.org:ADTP/273998 |
| Date | January 2008 |
| Creators | Flewellen, James Lewis |
| Publisher | University of Canterbury. Physics and Astronomy |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright James Lewis Flewellen, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
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