Methods Of Combing Phase Image From Multi-channel RF Coils In MRI

Over the past three decades, MRI research focuses on magnitude imaging, while the phase imaging has been neglected. There has been a rapid development of phase imaging methods over the past years and a concurrent development in phased array RF receiver coils. They have stimulated the development of methods that are reliant on the phase of the MR signal for contrast; particularly phase imaging, susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM). However, there is no standard method for the direct combination of phase images from multiple channel coils.To obtain the phase images with high quality, we adopted four different methods for the combination of phase images from four channels RF coils. They were respectively Phase Filter, Phase Difference, MCPC-C (Multi-Channel Phase Combination With Constant Offsets) and MCPC-3D (Multi-Channel Phase Combination Using Measured3D Phase Ofisets).Finally, methods were presented for the combination forward of phase images from multi-echo multi-channel RF coils. The results showed that MCPC-3D was the best method to combine the phase images. With MCPC-3D method together with multiple echo average method for combing multi-echo phase images from multi-channel RF coils, we have demonstrated that phase images can be reconstructed with high SNR and excellent grey-white matter contrast.