A dual-tuned transceive resonator for 13C{1H} MRS: two open coils in one

Proton-decoupled, 13C nuclear MRS experiments require a RF coil that operates at the Larmor frequencies of both 13C and 1H. In this work, we designed, built and tested a single-unit, dual-tuned coil based on a half-birdcage open coil design. It was constructed as a low-pass network with a resonant trap in series with each leg. Traps are tuned in alternate legs such that the two resonant modes arise from currents on alternate legs. The coil performance was compared with that of a dual-tuned coil consisting of two proton surface coils operating in quadrature and a single surface coil for 13C transmission and reception. The half-birdcage coil was shown to produce a more homogeneous RF field at each frequency and was more sensitive to a 13C signal arising from regions further from the coil surface. The applicability of the coil in vivo was demonstrated by acquiring a proton decoupled, natural abundance 13C glycogen signal from the calf of a normal volunteer. Copyright (c) 2013 John Wiley & Sons, Ltd.