Please use this identifier to cite or link to this item:
https://knowledgecommons.lakeheadu.ca/handle/2453/4527
Title: | A mechanism for simplified scanner control with application to MRI-guided interventions |
Authors: | MacDonald, Matthew A. |
Keywords: | Magnetic Resonance Image (MRI)-guided interventions |
Issue Date: | 2016 |
Abstract: | Magnetic Resonance Image (MRI)-guided interventions involving percutaneous biopsies of lesions, or trajectory alignment with prospective stereotaxy are conducted in real time using rapid image acquisition. A mechanism of passively localizing a device and calculating its orientation is desired to improve interventional outcomes in these situations. In this work, we propose and evaluate an image-based technique to determine the position and alignment of a linearly shaped interventional device within an ex-vivo tissue specimen. Low resolution 3D orientation scan data is processed to produce a virtual line tting using principal component analysis. The line tting algorithm was incorporated into a biopsy needle tracking system implemented with an MRscanner operated using a footswitch. A GUI application was written to collect foot pedal input and display automated visualization of device placement inside the scanner room. Placement time trials (N=3) conducted with this system using porcine muscle and phantom samples suspended in rigid frames with inserted gadolinium-enhanced targets. The mean targeting error across all directions was 3:6 mm and 5:1 mm for the phantom trials and ex-vivo trials respectively. The average entry-to-target time was 247 sec. Device localization during trials was adequate to contain a 11-gauge titanium biopsy needle within a visualization slice volume of 10 mm after 93:8% of alignments over insertion lengths between 30 mm to 110 mm at insertion angles between 1:4 to 20 from the static magnetic eld and frequency encoding axes. Practical considerations were identi ed and occupational exposure measurements were collected as part of determining the system's overall feasibility. |
URI: | http://knowledgecommons.lakeheadu.ca/handle/2453/4527 |
metadata.etd.degree.discipline: | Engineering : Electrical and Computer |
metadata.etd.degree.name: | Master of Science |
metadata.etd.degree.level: | Master |
metadata.dc.contributor.advisor: | Pichardo, Samuel |
Appears in Collections: | Electronic Theses and Dissertations from 2009 |
Files in This Item:
File | Description | Size | Format | |
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MacDonaldM2016m-1b.pdf | 7.42 MB | Adobe PDF | View/Open |
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