title: Simultaneous radiofrequency (RF) heating and magnetic resonance (MR) thermal mapping using an intravascular MR imaging/RF heating system.
abstract: Previous studies have confirmed the possibility of using an intravascular MR imaging guidewire (MRIG) as a heating source to enhance vascular gene transfection/expression. This motivated us to develop a new intravascular system that can perform MR imaging, radiofrequncy (RF) heating, and MR temperature monitoring simultaneously in an MR scanner. To validate this concept, a series of mathematical simulations of RF power loss along a 0.032-inch MRIG and RF energy spatial distribution were performed to determine the optimum RF heating frequency. Then, an RF generator/amplifier and a filter box were built. The possibility for simultaneous RF heating and MR thermal mapping of the system was confirmed in vitro using a phantom, and the obtained thermal mapping profile was compared with the simulated RF power distribution. Subsequently, the feasibility of simultaneous RF heating and temperature monitoring was successfully validated in vivo in the aorta of living rabbits. This MR imaging/RF heating system offers a potential tool for intravascular MR-mediated, RF-enhanced vascular gene therapy.
authors.affiliation: Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Bensheng
authors.initials: B
authors.lastname: Qiu
authors.forename: Abdel-Monem
authors.initials: AM
authors.lastname: El-Sharkawy
authors.forename: Vaishali
authors.initials: V
authors.lastname: Paliwal
authors.forename: Parag
authors.initials: P
authors.lastname: Karmarkar
authors.forename: Fabao
authors.initials: F
authors.lastname: Gao
authors.forename: Ergin
authors.initials: E
authors.lastname: Atalar
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000033:anatomy & histology* / Q000502:physiology*; D002404:Catheterization / Q000379:methods*; D006979:Hyperthermia, Induced / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011817:Rabbits; D000078702:Radiofrequency Therapy; D018511:Systems Integration; D013817:Thermography / Q000379:methods*