Multi-Tuned Radiofrequency Coil Using Microfluidically Tunable Capacitor for Magnetic Resonance Imaging/Spectroscopy at 7-Tesla

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 multi-nuclear Radiofrequency coils in order to interrogate the proton (1H) and other nuclei (X-nuclei) in the human body. Such coils provide anatomical images by acquiring (1H) spectra and metabolites 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 signal-to-noise-ratio is low. The main advantages of using multinuclear Radiofrequency coils are that they speed up the imaging process and reduce the spatial positioning error that might arise when replacing the Radiofrequency 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 Radiofrequency coil has been designed by using microfluidically tunable Radiofrequency 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 in order to excite several nuclei at a field strength of 7-Tesla.