Magnetic resonance imaging (MRI) has revolutionized the field of cognitive neuroscience as it allows researchers to noninvasively map brain function in response to stimulus or task demands. However, the acquisition of MR images generates substantial acoustic noise, so that imaging studies of speech, language and hearing are problematic.
One proven solution for reducing acoustic noise in MRI scanners is the use of micro-perforated panels placed in the bore of the scanner. They can be applied to existing scanners with minimal cost and are suitable for sterile environments. Although these panels result in quantifiably lower noise levels, measured with microphones in an empty MRI, the improvement has not been quantified with a patient in the scanner bore, which dramatically affects the acoustic noise field.
This thesis tested the reduction of noise inside the MRI environment using a previously designed micro-perforated acoustic absorber panel. These panels resulted in quantifiably lower noise levels with a volunteer in the scanner bore, however the reduction was not sufficient for significant differences in volunteer perceptions. Volunteers were generally unable to perceive a difference in noise between scans with and without absorbers and no reduction of fatigue was observed. Also no significant change in cortical activity was found between scans done with and without absorbers during an auditory function MRI study. Further testing could include designing a micro-perforated acoustic absorber for a specific scan sequence for maximum attenuation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-09-25 16:54:41.118
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/7520 |
| Date | 26 September 2012 |
| Creators | FRASER, ROBERT |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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