PURPOSE: To develop a novel endovascular heating source using a magnetic resonance (MR) imaging guidewire (MRIG) to deliver controlled microwave energy into the target vessel for thermal enhancement of vascular gene transfection. MATERIALS AND METHODS: A 0.032-inch MRIG was connected to a 2.45-GHz microwave generator. We 1) calculated the microwave power loss along the MRIG, 2) simulated the power distribution around the MRIG, 3) measured the temperature increase vs. input power with the MRIG, and 4) evaluated the thermal effect on the balloon-compressed/microwave-heated aorta of six living rabbits. In addition, during balloon inflation, we also simultaneously generated high-resolution MR images of the aortic wall. RESULTS: The power loss was calculated to be 3.9 dB along the MRIG. The simulation-predicted power distribution pattern was cylindrically symmetric, analogous to the geometry of vessels. Under balloon compression, the vessel wall could be locally heated at 41 degrees C with no thermal damage apparent on histology. CONCLUSION: This study demonstrates the possibility of using the MRIG as a multifunctional device, not only as a receiver antenna to generate intravascular high-resolution MR images of atherosclerotic plaques and as a conventional guidewire to guide endovascular interventions during MR imaging, but also as a potential intravascular heating source to produce local heat for thermal enhancement of vascular gene transfection. Copyright 2002 Wiley-Liss, Inc.
PURPOSE: To develop a novel endovascular heating source using a magnetic resonance (MR) imaging guidewire (MRIG) to deliver controlled microwave energy into the target vessel for thermal enhancement of vascular gene transfection. MATERIALS AND METHODS: A 0.032-inch MRIG was connected to a 2.45-GHz microwave generator. We 1) calculated the microwave power loss along the MRIG, 2) simulated the power distribution around the MRIG, 3) measured the temperature increase vs. input power with the MRIG, and 4) evaluated the thermal effect on the balloon-compressed/microwave-heated aorta of six living rabbits. In addition, during balloon inflation, we also simultaneously generated high-resolution MR images of the aortic wall. RESULTS: The power loss was calculated to be 3.9 dB along the MRIG. The simulation-predicted power distribution pattern was cylindrically symmetric, analogous to the geometry of vessels. Under balloon compression, the vessel wall could be locally heated at 41 degrees C with no thermal damage apparent on histology. CONCLUSION: This study demonstrates the possibility of using the MRIG as a multifunctional device, not only as a receiver antenna to generate intravascular high-resolution MR images of atherosclerotic plaques and as a conventional guidewire to guide endovascular interventions during MR imaging, but also as a potential intravascular heating source to produce local heat for thermal enhancement of vascular gene transfection. Copyright 2002 Wiley-Liss, Inc.
Authors: Fabio Settecase; Steven W Hetts; Alastair J Martin; Timothy P L Roberts; Anthony F Bernhardt; Lee Evans; Vincent Malba; Maythem Saeed; Ronald L Arenson; Walter Kucharzyk; Mark W Wilson Journal: Acad Radiol Date: 2010-11-13 Impact factor: 3.173
Authors: Anthony Bernhardt; Mark W Wilson; Fabio Settecase; Leland Evans; Vincent Malba; Alastair J Martin; Maythem Saeed; Timothy P L Roberts; Ronald L Arenson; Steven W Hetts Journal: Acad Radiol Date: 2010-11-13 Impact factor: 3.173