The complexity of a stenosis or a section of a vessel shall be evaluated reliably. Therefore, there is provided a method including the steps of providing at least one image (4) of the stenosis or the section of the vessel, gathering (6) one geometrical feature value of the stenosis and/or or the section of the vessel from the at least one image, gathering (7) at least one intensity feature value based on a grey level intensity of the stenosis or the section of the vessel from the at least one image and automatically determining (8) a complexity value (9) related to the geometrical complexity of the stenosis or the section of the vessel in dependency on the at least one geometrical feature value and the at least one intensity feature value of the stenosis or the section of the vessel.
