Magnetic resonance imaging methods and apparatus.

摘要

A magnetic resonance imaging method and apparatus wherein a spin echo (52) and a gradient echo (60) are generated in each magnetic resonance sequence repetition. The spin echo is phase encoded by a phase encode gradient (44) in regular steps spanning about a quarter of k-space. More particularly, steps from -n to Gmax/2, where n is a small integer and Gmax is the maximum phase encode gradient. An off-set phase encode gradient (58) shifts the phase encoding of the gradient echo by Gmax/2 relative to the first phase encoding gradient. Data to fill the empty portions of k-space (142, 267) between -n and-Gmax are generated from the complex conjugate (140, 160), of the first echo data (74) and the second echo data (76). The first and second echo data and the complex conjugate data are transformed (122, 132, 146, 166) to generate parted image representations (124, 134, 148 168). The first echo image representation and the corresponding conjugately symmetric image representation are phase correction (126, 150) in accordance with a phase map (112) derived from the central most first echo data (78). The partial image representations are summed (170) to produce a resultant image representation (172).