An introductory lecture on physics of MRI by Donald Plewes and Walter Kucharczyk (University of Toronto).
D.B. Plewes and W. Kucharczyk, "Physics of MRI: A Primer," Journal of Magnetic Resonance Imaging 35 (2012) 1038–1054. (Review: MR Physics for Clinicians) http://dx.doi.org/10.1002/jmri.23642