Dual-Tuned Monopole/Loop Coil Array for Concurrent RF Excitation and Reception Capability for MRI

Abstract

Radiofrequency (RF) coils based on two operating frequencies, or dual-tuned (DT) coils, for magnetic resonance imaging (MRI) in parallel with MR spectroscopy (MRS) and MR spectroscopy imaging (MRSI) are used to obtain morphological and metabolic information for early diagnosis of diseases. However, this method suffers from serious problems such as the extremely low signal sensitivity of X-nuclei and the long image acquisition time required for the two measurements. In this study, a single-channel DT coil was proposed for RF excitation/reception (Tx/Rx) of hydrogen (1H) and phosphorous (31P) by using a monopole antenna and a loop coil, and it was extended to an eight-channel volume coil at 7 T. To verify the DT coil performance, we compared the single RF port of the DT coil with monopole/loop geometry to the individual coil of the 1H monopole antenna and the 31P loop coil with a cylindrical phantom. The monopole/loop coil shows no magnetic flux interaction between individual coils despite the superimposed positions owing to the single RF port. The study results demonstrated that the proposed DT monopole/loop (DTML) coil can be extended to multiple RF Tx/Rx systems and can reduce the acquisition time with a single measurement.