Disclosed herein is an expansion catheter (100, 200) including: an expansion body (110, 210) which can be expanded an elongate main body (120, 220) to a distal section to which the expansion body is attached, the main body comprising a bent section (125, 225) and an imaging section (160, 272) by which the expansion body at the distal end is imaged from a proximal side of the bent section of the main body. In the first embodiment the bent section is transparent and the imaging section is within the main body, in the second embodiment the image section (272) is attached externally to the main body.
