Magnetic resonance image reconstruction from non-equidistantly sampled data

We consider the problem of magnetic resonance (MR) image reconstruction from non-uniformly sampled data acquired by echo-planar imaging (EPI) and spiral scan imaging techniques. In EPI, mismatches in the timings of the odd and even echoes collected with readout gradients of alternating polarity will result in “N/2” ghosting in the reconstructed images. We propose a new method using a calibration data set to correct this mismatch and hence to calculate accurate k-space trajectories. In order to reconstruct images at real-time speeds, we utilize a high speed optoelectronic device to perform two-dimensional discrete Fourier transform (DFT). Images reconstructed from EPI data, are presented to demonstrate that our method can successfully suppress the “N/2” ghosting and provide good contrast at real-time speeds. Image reconstructed from SSI data is also presented to show that our method can provide better sharp features and more detail in the reconstructed images