Methods and systems for assessing tissue of a subject include receiving a time series of signal intensity data capturing the transit of an imaging agent through tissue over a period of time, wherein the tissue comprises a plurality of calculation regions and wherein signal intensity in each calculation region over the period of time may be approximated by a time-intensity curve corresponding to the calculation region; determining, for each calculation region, a coefficient value that is related to at least a portion of the time-intensity curve corresponding to the calculation region; and converting the coefficient values across the plurality of calculation regions into a coefficient-derived image map.