A practical double-tuned 1H/31P quadrature birdcage headcoil optimized for 31P operation.
A double-tuned 1H/31P birdcage head coil for use with humans at 1.5 T is described. The coil was designed for proton-decoupled 31P excitation and reception and incorporated a number of practical features including optimized sensitivity for 31P, quadrature operation at 1H and 31P frequencies, and a radiofrequency (RF) mirror for improved B1 homogeneity. The design achieved similar B1 homogeneity at both 31P and 1H frequencies. Inductive matching was used to accommodate samples with large loading differences. A facile method for tuning and matching over a variety of sample loadings is presented, along with capacitively shortened bazookas for suppression of cable braid currents. The proton sensitivity, although down by approximately a factor of two compared with an optimized 1H birdcage head coil, was still ample for shimming and generation of scout images. Advantages of the design are discussed and proton-decoupled 31P spectra of human brain are presented.
Matson
G B
GB
Department of Pharmaceutical Chemistry, University of California, San Francisco, USA. jerrym@itsa.ucsf.edu
Vermathen
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P
Hill
T C
TC
D000255:Adenosine Triphosphate / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D004867:Equipment Design; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D011522:Protons; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
D011522:Protons; D000255:Adenosine Triphosphate