Dual-tuned floating solenoid balun for multi-nuclear MRI and MRS

Yang, Y.; Zhang, B.; Lu, M.; Yan, X. “Dual-tuned floating solenoid balun for multi-nuclear MRI and MRS.” Magnetic Resonance Imaging, Volume 115, 2025, Article 110268, DOI: 10.1016/j.mri.2024.110268. 

 

This study introduces a new, compact dual-tuned floating balun designed to reduce unwanted currents in MRI systems, which can affect performance and safety. Traditional floating baluns are bulky, especially in multi-nuclear MRI/MRS setups that use two RF systems. The new balun is smaller, fully removable, and does not require direct connections to cables. It uses inductive coupling between two solenoids and a two-layer design for better performance. Bench tests at 7 T showed high common-mode current suppression at both 1H and 23Na frequencies. This innovation improves MRI system efficiency by reducing size, enabling more coil elements, and simplifying cable management. 

Fig. 1. 

Design and construction of the dual-tuned FSB. (A) Schematic diagram of the dual-tuned FBB [21,22]. (B) Equivalent circuit schematic for dual-tuned FSB. The inner solenoid is floating and terminated with CL and pole-insertion circuit (CH and LH) to generate two resonant frequencies. The coaxial cable (grey) is winded around the inner solenoid to form the cable solenoid. (C) CAD model showing the mechanical structure for the dual-tuned balun. (D-E) Side view and front view of the fabricated balun for RG-174-like cable (Huber + Suhner G_02232_D). (F-G) Side view and front view of the fabricated balun for RG-223 cable. 

Explore Story Topics