Joint Estimation of Coil Sensitivities and Image in Parallel Magnetic Resonance Imaging
Parallel magnetic resonance imaging using multi-channel receiver coils has emerged as an effective tool to reduce imaging time in various applications. In general, exact knowledge of the coil sensitivities is needed to reconstruct the desired image. However, the issue of accurate estimation of coil sensitivities has not been fully addressed; thereby the errors limit the image quality achievable with the technology. In this paper, we model the image reconstruction problem as a blind multi-channel image restoration problem such that both the coil sensitivities and the desired images are estimated jointly. Specifically, a parametric model is assumed for the coil sensitivities whose parameters are solved by an iterative optimization algorithm along with image reconstruction. The proposed method has been tested on various data sets. The results from some in vivo data sets are shown to demonstrate the effectiveness of the proposed method especially when a rather large net acceleration factor is used.