Disclosed is a system and method for imaging strain of tissue, such as the heart, in a quantitative manner. The present invention provides images of strain, which corresponds to heart function, by tagging a tissue region of interest, and acquiring multiple images by tuning an MRI RF receiver to frequencies above and below the tagging frequency. Depending on the tagging spatial frequency, and the spread between the high- and low-tuning frequencies, linear measurements of strain may be made on a pixel by pixel basis. By selectively tagging the tissue of interest by use of selective excitation, images may be acquired sufficiently fast to provide anatomical and functional imagery within a single heartbeat. By acquiring additional images, dead tissue may be differentiated from contracting tissue as well as blood.