Intravascular MR imaging-guided balloon angioplasty with an MR imaging guide wire: Feasibility study in rabbits

PURPOSE: To develop a technique for intravascular magnetic resonance (MR)gu ided balloon angioplasty with use of an MR imaging guide wire. MATERIALS AND METHODS: An MR imaging guide wire (0.6-mm loopless antenna) t hat could be placed within a balloon catheter was manufactured. The guide w ire was expected to function as either an MR receiver probe in real-time MR imaging or a guide wire for use with interventional devices. Laparotomy wa s performed in eight rabbits, and a dilatable stenosis was created at the u pper abdominal aorta. Balloon angioplasty, Validated at pre- and postoperat ive MR aortography with renal contrast enhancement was performed by using a 1.5-T MR unit with a fast spoiled gradient-echo pulse sequence, short repe tition and echo times, and a rate of three frames per second. RESULTS: During MR tracking, the entire length of the MR imaging guide wire was always visible as a band of high signal intensity. In all cases, the M R imaging guide wires were passed through the aortic stenoses dilated by me ans of balloon inflation. Before balloon angioplasty, flow in the aorta dis tal to the stenosis was decreased, which caused mild contrast enhancement i n each kidney. After balloon angioplasty, distal flow was restored, resulti ng in substantial renal enhancement. CONCLUSION: The MR imaging guide wire is a potential tool for use in endova scular interventional MR imaging.