Inter-Channel Correlation-based EMI Noise Removal for Shielding-Free Low-field Portable MRI

Motivation: The current electromagnetic interference (EMI) noise removal approaches for low-field portable magnetic resonance imaging (MRI) only focus on single receive coil EMI removal, which ignores noise relationship among coil elements of RF coil arrays. Goal(s): Our goal was to remove EMI noise in receive coils not only related to EMI detectors, but also among receive coil elements. Approach: A signal correlation matrix was constructed from signals acquired by EMI coils and receive coils, and decorrelation matrix was calculated for EMI noise removal. Results: Phantom results and pilot in vivo human brain images showed that the proposed method have better EMI noise removal rate. Impact: The proposed EMI noise removal method for unshielded low-field MRI can better improve signal-to-noise ratio (SNR) compared to state-of-the-art methods, which enable the EMI noise removal for array coils in low-field portable MRI application.