Small bore Magnetic Resonance Imaging (pMRI) is being used to investigate the contribution of bone structure changes to the development of osteoporosis and the evaluation of joint integrity in the diagnosis and treatment of osteoarthritis. We have developed image processing software t bone structure, derived from peripheral Quantitated Computed Tomography (pQCT) images, has identified the importance of the contribution of this variable to bone fracture risk. Currently we are working to extend the analysis of bone structure derived from a single cross-sectional pQCT image to the assessment of fracture risk for a whole bone assessed using pMRI. This will require the evaluation of trabecular bone structure and distribution as well as the spacial organization of cortical bone.

The second area of research is the establishment of appropriate measurement conditions for the assessment of the integrity of the knee joint using pMRI. Knee integrity will be based on an evaluation of cartilage, periarticular bone, synovium, ligaments and menisci. The results of such assessments will be applied both to the evaluation of patients suffering from osteoarthritis and the measurement of efficacy of putative treatments for osteoarthritis. o derive quantitative assessments of bone structure.

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Magnetic Resonance and Electrical Impedance Methods
Dr. Jerry Moran
http://www.science.mcmaster.ca/medphys/MRI/main.php

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Optical Diagnostics and Therapeutics
Dr. Michael Patterson

Patterson and his group are based at the Juravinski Cancer Centre, located at the Henderson campus of Hamilton Health Sciences. The aim of the group is to use optical techniques to diagnose, treat, and monitor response of cancer in patients and preclinical animal models. The current research activities are in three main areas: optical imaging, photodynamic therapy, and optical spectroscopy.

Optical molecular imaging of small animals is a powerful technique for tracking cells and specific genes or proteins by bioluminescence or fluorescence. One shortcoming of the method is that images are distorted by the attenuation of excitation and emission light in the animal. We are working on ways to measure the optical properties of the tissues in individual animals and correct the images for these effects. Some preliminary work has also been done with Kathy Murphy (Psychology) and David Jones (Computer Science) on speckle imaging of blood flow in the rat brain and spectral imaging of the visual cortex.

Photodynamic therapy is a photochemical treatment for cancer and other diseases. Our research ranges from mechanistic studies at the cellular level to clinical trials. The goal is to understand how the biophysical variables of the treatment determine the outcome, and to devise methods to measure those variables in the clinical environment. Fiber optic devices are developed for patient irradiation and for spectroscopy of photosensitizing compounds.

Optical spectroscopy encompasses absorption, fluorescence, and Raman techniques. While all of these are used routinely in the analytical laboratory, their application in vivo is complicated by multiple scattering of light in tissue. We are using mathematical models of light propagation in tissue to understand how multiple scattering affects the detected signal and to recover the true concentration of the active molecule. This research has many applications such as noninvasive measurement of tissue oxygenation and pharmacokinetics of fluorescent compounds.

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Radiation Exposure Geochronology
Dr. Jack Rink

A variety of methods are used in our group to determine the age of coastal landforms (sand dunes, storm deposits), and archaeological sites and cultural materials (stone tools, human remains)related to questions of human evolution. The main techniques are electron spin resonance and optical luminescence dating which allow age determinations throughout the last 5 million years of earth history. We are active in both commercial work and research collaborations and are actively seeking new graduate students. http://www.science.mcmaster.ca/geo/research/age/jack_home.htm

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Scanning proton microprobe and PIXE analysis
Dr. Iain Campbell

The facilities at the Guelph accelerator lab include a conventional PIXE beamline and a proton microprobe beamline which is used for micro-PIXE analysis and imaging. The emphasis is on collaborative studies of environmental specimens ranging from air pollution particulate through mineral grains to fish otoliths: there is also work on diseased tissue specimens and in the materials science area. http://www.physics.uoguelph.ca/www_physics/personal_site.php?idx=17

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