Magnetic resonance reconstruction from projections using half the data

The acquisition of radial lines in 2-D Fourier space (k space) allows the realization of the extremely short echo times useful in the imaging of short-T2 species and flow using Magnetic Resonance (MR). The disadvantage of this imaging method, which is also known as projection reconstruction, is that in order to prevent aliasing at a given resolution, (pi) times as many excitations are required as the conventional 2-D Fourier transform or spin-warp acquisition. The authors propose an acquisition and reconstruction method that halves the required number of radial lines and excitations by using the properties that projections are real or have slowly varying phase and that radial acquisition methods are over-sampled at the center of k space. This method preserves resolution while reducing imaging time at the expense of signal-to-noise ratio (SNR). This has been verified with both phantom and human subjects.