Reduced scan time cardiac gated magnetic resonance cine and flow imaging

Abstract

A positive portion (52) of k-space and a negative portion (56) are both divided into n segments (FIG. 2 ). In each cardiac cycle, a multiplicity of field echoes (106) are generated, which multiplicity of gradient echoes are divided into groups of n contiguous echoes. Within each group, the echoes are all from either the positive portion of k-space or the negative portion of k-space. Preferably, every group of each cardiac cycle has the same views in the same order to generate like, time displaced frames of a cine image sequence. Within each group, the views from the central-most segment n are collected in the middle of the group, views from progressively less central, higher frequency segments are progressively less centrally located within each group with views of the most peripheral, highest frequency segments being collected at the ends of the group. The total number of segments is an integer multiple of four times the number of views per group to facilitate 0.degree.-180.degree. phase cycling. Quantitative flow images are generated by expanding each group to include corresponding views from the k-space for reference image data and a flow sensitized image data. The echo signals for the reference and flow sensitized images for each frame are separated and reconstructed into reference and flow sensitized images for each frame. The reference and flow sensitized images are subtracted to generate a quantitative flow image for each frame.