Catheter device with an imaging device, in particular for optical coherence tomography, for insertion into a bifurcation region of a vessel of the human or animal body, comprising a main catheter with a balloon arranged thereupon and inflatable via a supply line, for the purpose of occluding the vessel proximal to the bifurcation, with a total of two further occlusion balloons for positioning in one of the two vascular branches in each case distal to the bifurcation being arranged on the main catheter and/or at least one auxiliary catheter, at a distance from the first balloon, such that they can be inflated for the distal occlusion of the respective vascular branch.