An apparatus for quantifying contrast agent behavior of an administrated contrast agent within a region of interest, comprises an imaging device configured to acquire images of a subject and processing structure communicating with the imaging device. The processing structure is configured to process image data of the acquired images to yield a time sequence of images, I(t), at a location (I) outside of the region of interest that detect contrast agent concentration before the contrast agent enters the region of interest and to yield a time sequence of images, J(t), at a location (J) within the region of interest that detect the contrast agent concentration as the contrast agent perfuses the region of interest. The processing structure is further configured to deconvolve I(t) from J(t) to determine a vector describing the time estimate of the impulse response function, R′(t), for the region of interest, where the shape of the vector is constrained using physiologic and physical considerations and I(t)R′(t) is the maximum likelihood estimate of J(t), where denotes convolution, and configured to determine the behaviour of the contrast agent in the region of interest based on the determined vector.
