Decoupling Low Field Array Coil Using High Impedance Preamplifier

Motivation: Phased array coils can benefit low field MRI via higher SNR or parallel imaging. However, isolation preamplifiers at very low frequency are difficult to source, and the bandwidth of LC resonance circuits at very low frequency can be narrow. Goal(s): To investigate a different approach to array coil decoupling at low field. Approach: Instead of using an LC network with low Z preamplifier, a high Z preamplifier with RF transformer can be directly used to decouple array coils. Results: More than 20dB coil decoupling over a bandwidth of 1MHz was achieved around a readout frequency of 1MHz. Impact: A simple and efficient method to decoupling array coil at low field is investigated in this work. Without the need of complicated matching and customize-built isolation preamplifier, broadband and sufficient decoupling on array element can be achieved.