a medical imaging system includes an imaging device for producing temporally spaced image representations , a memory for storing the image representations , and a processor . the processor aligns the image representations by iteratively deriving a transform between progressively smaller sub - sets of pixels in temporally adjacent images until the sub - sets converge , and , applies the transform to the temporally adjacent images . the processor further sorts selected pixels in a region of interest spatially within each of the image representations for further processing by classifying pixels in the images according to a characteristic indicative of an absorption rate of the contrast agent . the processor further establishes correspondence between the selected pixels over successive image representations by generating masks for a particular classification of pixels , based on the generated masks , computing textural properties of the particular classification of pixels across the temporally spaced images , and computing co - occurrence matrices between successive image representations based on the textural properties . the processor further determines and displays a curve indicative the contrast agent in the selected pixels over time .