A method of visualizing changes in blood flow in a digital subtraction angiography (DSA) image sequence is disclosed. A time-contrast curve is generated for all pixels in each image of the DSA image sequence. A reference parameter for each time-contrast curve to be used as a first time point is specified. The value of the reference parameter for each time-contrast curve is determined and an arbitrary parameter is specified for each time-contrast curve to be used as a second time point. An output image is generated by applying a color-coding of the difference between the first time point and the second time point to all pixels.