Multi-tuned RF Coil using Microfluidically Tunable RF Capacitor for MRI/MRS at 7T

Abstract

Multi-nuclear magnetic resonance imaging and spectroscopy are considered valuable tools due to their capability of diagnosis and monitoring of several diseases. They require multinuclear RF coils to interrogate the proton (1H) and other nuclei (X-nuclei) in the human body. Such coils provide anatomical images by acquiring (1H) spectra and metabolities information by acquiring spectra of X-nuclei. In addition, the high signal received from proton (1H) is used for B0 shimming purposes. However, the signal strength for these X-nuclei is too low. Hence, the signalto-noise-ratio (SNR) is low. The main advantages of using multinuclear RF coils are that they speed up the imaging process and reduce the spatial positioning error that might arise when replacing the RF coil in order to perform imaging of different nuclei. In addition, comfortable environment will be provided for patients by avoiding any inconvenience of moving out and asking to replace the coils. In this paper, a multi-tunable microstrip transmission line RF coil has been designed by using microfluidically tunable RF capacitor. This capacitor offers a wide range of capacitance tuning which extends between Cmin=1.76 pF and Cmax=48.7 pF. Hence, a wide range of resonant frequencies (fmin=75 MHz - fmax=298 MHz) can be offered by this coil to excite several nuclei at a field strength of 7T..