Quantitative Magnetic Resonance Imaging - Mechanisms of Tissue Contrast
Magnetic Resonance Imaging (MRI) has proved to be a very useful and spectacular diagnostic tool that allows to image soft tissue non-invasively. Measured MRI signal characteristics depends on the physical and chemical processes experienced by water molecules in tissues. Our work involves studies that quantitatively characterize the MRI signal behaviour in various types of normal and pathological tissues in order to obtain information about tissue microstructure. Quantitative MRI can be used to estimate physical tissue parameters such as: cell dimensions, cell membranes permeabilities, translational and rotational motion of water in different tissue compartments (intra- and extracellular), extra- and intracellular volume fractions.
Current research involves measuring basic "in vitro" NMR properties of neural tissue using a 1.5T SMIS spectrometer and developing tissue multi-compartmental models is order to correlate experimental data with tissue histopathology. We are particularly interested whether NMR measurements such as T1, T2 relaxation times, diffusion and Magnetization Transfer between water and macromolecules can be used to evaluate the processes of nerve degeneration and spontaneous regeneration following trauma. Simultaneously, we use a clinical MR system (1.5 and 3T GE Signa) to develop diagnostic tools that would allow characterizing the nerve tissue microstructure in vivo. We explore the efficacy of the MRI experiments in evaluation of the central nervous system such as Multiple Sclerosis, Alzheimer, cancer and Wallerian degeneration following trauma.
For further information, please visit homepage http://sunnybrook.ca/team/member.asp?t=13&m=163&page=172
Graduate Students:
- Colleen Bailey
- Kim Desmond
- Voytek Gretka
- Firas Moosvi
- Wendy Oakden
Selected References:
Link to Pubmed Publications-
Stanisz GJ & Henkelman RM. 1998. Diffusional Anisotropy of T2 Components in Bovine Optic Nerve. Magn Reson Med. 40:405-410.
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Stanisz GJ, Kecojevic A, Bronskill MJ, Henkelman RM. 1999. Characterizing White Matter with Magnetization Transfer and T2 Relaxation. Magn. Reson.Med. 42: 1128-1136.
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Stanisz GJ & Henkelman RM “Gd-DTPA Relaxivity depends on macromolecular content”, Magn. Reson. Med. 44:665-667 (2000)
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Henkelman RM, STANISZ GJ, Graham SJ “Magnetization Transfer in MRI: A Review” NMR in Biomed. 14:57-64 (2001)
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Stanisz GJ, Midha R, Munro CA, Henkelman RM, “MR properties of rat sciatic nerve following trauma” Magn. Reson. Med. 45:415-420 (2001)
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Stanisz GJ, Yoon R, Joy M, Henkelman RM “Why does MTR change with neural depolarization?”, Magn Reson Med 47:472-475 (2002)
