A method of localizing and preferably visualizing a vein within a limb, preferably within a leg, of a patient, with an imaging device, the method comprising the following steps: fully or partially collapsing at least a segment of the vein to be localized at a collapsing site during a collapsing step； inducing blood flow within the vein at the collapsing site, while the segment of the vein is fully or partially collapsed, during a pumping, step； and visualizing the collapsing site with the imaging device in an imaging step at least during the pumping step.
