in vitro and in vivo visibility performance. (a) Phantom MR image acquired with three channel catheter. (b) The active catheter was inserted percutaneously from the femoral artery, through the aorta, and into the left subclavian artery. (c) Multi-slice volume-rendered real-time MR of procedure described in panel (b) depicting the anatomic context. Device-related signal is evident in all slices. Independent catheter receiver channels allow colorized reconstruction of the tip (first (arrow) and third coil, green; middle coil, red; catheter shaft, blue).