Magnetic resonance-guided vascular catheterization: Feasibility using a passive tracking technique at 0.2 Telsa in a pig model

The objective of this study was to demonstrate in an animal model the feasi bility of a passive tracking technique for catheter visualization of magnet ic resonance (MR)-guided endovascular procedures. All experiments were perf ormed in a 0.2 Tesla open MR system, Susceptibility-based catheters and gui de wires were introduced into the aorta and were advanced selectively into the splenic and renal arteries under MR guidance. Based on a previously acq uired contrast-enhanced magnetic resonance angiography (MRA) data set, the catheter positioning was performed by using a single-slice true fast imagin g with steady state precession (FISP) sequence with a frame rate of 1.3 sec onds. Contrast-enhanced MRA was performed in all animals. All catheters wer e advanced without complications into the aorta and were introduced into th e proximal parts of the right renal and splenic arteries under MR guidance. Catheter manipulations were more difficult in the distal parts of these ve ssels due to the more complex anatomy. Passive catheter tracking is a valua ble and technically robust alternative to active tracking methods, because it does not require additional hardware and, thus, can be implemented and u sed easily with any open MR imaging system. (C) 1999 Wiley-Liss, Inc.