Background: None of the currently available Good Manufacturing Practices (GMP)-grade MRI cell labelling agents are approved for use in Canada. There is one iron oxide nanoparticle GMP grade preparation that is commercially available but it is not suitable for labelling the immune cell populations the investigators are interested in tracking in vivo. The investigators have, instead, chosen to develop the commercially available, GMP-grade 19F-based perfluorocarbon, known as Cell Sense, for the purpose of tracking immune cell-based vaccine therapies in vivo. This agent has been successful used in a phase I clinical trial in United States and is approved for a second trial current recruiting, under the oversight of the FDA.