A method for selective detection, with a thermographic plate, of traces of blood flow that differ from traces with a correct course in vessels at different depths, particularly of the breast, which consists in that a sequence of thermographic images is taken which are acquired by a thermographic plate gently pressed against the skin, which is cooled before each photograph with an air jet whose duration is correlated to the depth of the portion of vessel being investigated, the traces of vessels with a correct course having a substantially centripetal direction with respect to the breast and tapering toward the center of the organ so as to confirm a temperature of the blood flow which decreases because the vessel gradually branches and because the depth from the surface of the skin increases.
