Self-calibrating Coil Sensitivity Profiles for Parallel Imaging Based on Anisotropic Diffusion

-Calibration of the spatial sensitivity functions of coil arrays is a crucial element in parallel magnetic resonance imaging (PMRI).In order to overcome the sensitivity miscalibration errors introduced by pre-scan calibration method and decrease the total examination time, a new self-calibrating method for estimating the coil sensitivity profiles was proposed in the paper. From a fullysampled central region of a variable-density k-space acquisition, the sensitivity calibration images were directly extracted, and then were adaptively smoothed by a new anisotropic diffusion scheme to extract encoding effects of coil sensitivities. When the estimated coil sensitivity profiles were applied to reconstruct the full Field-Of-View image from the uniformly under-sampled MR data when undersample rate was greater than 2, the experimental results showed that the quality of reconstruction image was evidently improved. Therefore, this self-calibrating method for calculating sensitivity profiles is suitable for much faster imaging in parallel magnetic imaging. Meanwhile, the paper suggest that the suitable number of central k-space lines for generating the internal reference images should be chosen between 8 to 20.