Reduction of MR image degradation due to added gradient field pulse

摘要

A pair of gradient field pulses of the same applied time and the same intensity are applied before and after a radio-frequency (RF) refocusing pulse (180 DEG pulse) as additional gradient field pulses to enhance the phase shift of a transverse magnetization spin, caused by the diffusion of a molecule including a target nuclide. To compensate for image deterioration caused by an unnecessary field distribution which is produced by the additional gradient field pulses, a compensation gradient field pulse dGcp and a compensation offset gradient field dGoffset are applied and a center frequency at the time of receiving and detecting an echo signal is shifted by df0.