Active Magnetic Shielded Cancelling Coils for Direct Detection of MR Signals with an Atomic Magnetometer in Ultra-Low Field MRI

Takenori Oida¹, Masahiro Tsuchida¹, Tetsuo Kobayashi¹

Optically pumped atomic magnetometers (OPAMs) do not require cryogenic cooling and allow us easily to measure extremely small magnetic fields including MR signals. Recently, an ultra-low field (ULF) MRI system with an OPAM has been attracted attentions. In this study, we proposed the active magnetic shielded cancelling coils for direct detection of MR signals with an OPAM. Results of magnetic field distribution analyses showed that the proposed active magnetic shielded coils could sufficiently reduce the magnetic field distortion caused by the cancelling coils, demonstrating their feasibility of direct detection of MR signals.