The method comprising acquiring and analyzing by computer means image information of video sequences of two or more dimensions obtained from contrast-enhanced signals, for example ultrasound, coherence tomography, fluorescence images, or Magnetic Resonance Imaging, of a body part or tissue, for example of an organ, of a living subject; detecting events from said information of video sequences; selecting a Region of Interest of said body part or tissue; computing a first graph representative of a local vascular network of said image information of video sequences in which the edges of the graph are estimated by the temporal relationship among spatially remote signals of said image information of video sequences within a set of video sequences; and using said graph for assessment of vascular networks.