| 摘要 |
A magnetic resonance imaging apparatus having a static magnetic field source, a plurality of radio frequency magnetic field sources and a plurality of gradient magnetic field sources for generating a gradient magnetic field is provided. The static magnetic field source generates a static magnetic field for aligning a spin vector of an object in a direction of the magnetic field and plurality of radio frequency magnetic field sources generate a radio frequency magnetic field for rotating the spin vector by an angle. The apparatus further includes a processor for generating a plurality of radio frequency excitation pulses for the plurality of radio frequency magnetic field sources and a plurality of gradient excitation pulses for the plurality of gradient magnetic field sources. The second half of each of the plurality of radio frequency excitation pulses comprises a time-reversed first half of a respective one of the plurality of radio frequency excitation pulses and the second half of each of the plurality of gradient excitation comprises a time-reversed and sign-reversed first half of a respective one of the plurality of gradient excitation pulses. The average value of each of the plurality of gradient excitation pulses is zero.
|
