Seminar: PET-MR Imaging Application in Cell Tracking Studies

Fri., Oct. 19, 2012 3:30 p.m. - Fri., Oct. 19, 2012 4:30 p.m.

Location: CL 305

Positron emission tomography (PET) imaging is widely used in clinical oncology for staging and the assessment of treatment in cancer patients. Pre-clinical studies involving animal models of diseases also benefit greatly from PET imaging techniques. I will talk about our ongoing projects on the application of PET imaging for cell tracking in cardiac stem cell therapy in a rat model of heart failure, and PET-MR multimodality imaging, with an overview of PET imaging.

The principle of PET imaging is the simultaneous detection of two back-to-back 511-keV photons created after the positron-electron annihilation processes, where the positron is emitted from the decay of a radioactive nucleus. In clinical oncology, for example, a radioactive sugar (18F-FDG) is injected into the body (18F is a positron emitting radioisotope). FDG is like glucose and is taken up by highly metabolic cancerous cells. Therefore, 18F-FDG-PET images map out the distribution of cancerous sites and help the physicians with diagnosis or staging of the cancer in a patient. The same principles can be applied in cell tracking in cardiac stem cell therapy in animals (or human). Stem cells have the capability to transdifferentiate to other cell types. If they are implanted in an injured tissue, over time, tissue can be repaired. In our project, we will use stem cells to treat injured heart tissue in a rat that has had a heart attack. To track the stem cells inside the rat, we label (tag) them with 18F-FDG and then inject them into the animal. PET imaging is then used to quantify the biodistribution of the implanted stem cells in the animal. Radioactive 18F-FDG can affect the biological function and structure of the stem cells. In-vitro experiments are conducted to address these effects. Results of such experiments and procedures for optimum labeling conditions will be described.

PET and MR (magnetic resonance) imaging techniques provide different information (physiological vs anatomical) from the same subject. I will describe few of the projects that are underway to develop PET-MR multimodality imaging techniques for application in biomedical studies.

Speaker: Dr. Esmat Elhami, PhD, Assistant Professor, Department of Physics, University of Winnipeg