title: Calibrated uncoupling of tightly coupled concentric surface coils for in vivo NMR.
abstract: Three known active methods of detuning rf coils have been tested by determining the efficiency of uncoupling two concentric transmit surface coils in a double-coil probe. In a comparison at 80 MHz, the method based on the use of lambda/4 cables was found to have advantages. These methods utilize the introduction of an additional resonance at the frequency of interest to completely detune a coil. By offsetting the detuning of the coil (by offsetting the additional resonance) a calibrated fraction of the rf field of the detuned coil can be added to or substracted from the rf field of the neighboring coil.
authors.affiliation: School of Science, Griffith University, Nathan, Queensland, Australia.
authors.forename: M R
authors.initials: MR
authors.lastname: Bendall
mesh_terms: D002138:Calibration; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods