Date of Award
2008
Degree Type
Thesis
Degree Name
Master of Science
Program
Medical Biophysics
Supervisor
Dr. Brian K. Rutt
Abstract
Cell labeling and tracking is a valuable tool for understanding cellular processes, diseases, and targeted cell therapies. Magnetic resonance imaging (MRI) is an attractive modality for cellular imaging due to its excellent spatial resolution and the commercial availability of a variety of proven contrast agents. Siiperparaniagnetic Iron-Oxide (SPIO) is a highly sensitive contrast agent for cell labeling and tracking that is used frequently in our lab. SPIO agents tend to produce negative contrast or signal loss in MR images, making it an indirect method for detecting cells. There has been a recent movement towards positive contrast imaging of SPIO particles. In this case, cells labelled with SPIO appear as bright spots and all other background signal is suppressed. It is thought that this direct measure may provide increased specificity when detecting small numbers of cells. In this thesis, I set out to create a new positive contrast mechanism. First, I simulated the effects of iron-loaded cells for various loadings and imaging parameters. This was used to predict the behaviour I would encounter' during my experiments and set the requirements for my pulse sequence. Second, I designed and programmed an Echo Planar Spectroscopic Imaging (EPSI) pulse sequence. The purpose of this pulse sequence was to collect spatial and spectral information in iron-loaded cell phantoms. Third, I developed a post-processing algorithm used to spectrally resolve the presence of iron-loaded cells. Finally, a phantom study was conducted to test my hypothesis and to validate the design and simulation work laid out in this thesis. The results of this phantom study confirmed through optical validation that this new technique can detect single iron-loaded cells.
Recommended Citation
Sodomsky, Matthew, "Spectrally Resolved Positive Contrast (SRPC): Single cell detection using 3D Spectroscopic Imaging with optical validation" (2008). Digitized Theses. 4556.
https://ir.lib.uwo.ca/digitizedtheses/4556