Development of Ultra-Low Field Magnetic Resonance Imaging System at 1 mT

Ultra-low field (ULF) magnetic resonance imaging (MRI) is considered an innovative MRI technique that can be combined with magnetoencephalography (MEG). In this study, a 1-mT ULF-MRI system without pre-polarization aiming at combining MEG developed. The intensity of the static B0 decided to 1 mT because limitation exposed our sensor made superconducting quantum interference devices (SQUIDs). A square-shaped (750 mm × 750 mm) B0-coil based on Merritt-type configuration fabricated. inhomogeneity less than 0.07 % in ±125 area. Further, induction coil employed detect signal instead SQUID sensors confirm feasibility realizing measurement technique. Relaxation time measurements and MR phantom CuSO4 aqueous solution are performed. Reasonable longitudinal transverse relaxation times obtained, clear shapes obtained using gradient- spin-echo pulse sequences system. These results indicate potential proposed effectively integrate systems pre-polarization.