The invention relates to a catheter device, with a position sensor system, for treatment of a partial or complete vessel blockage under image monitoring, with the catheter device featuring a treatment catheter of a vessel blockage, especially by removal or destruction of plaque and/or expansion of the vessel, which is embodied as an integrated unit, especially as a combination catheter, with an OCT catheter and an IVUS catheter for image monitoring and with the position sensor system.