HIGH-SPEED MAGNETIC RESONANCE IMAGING METHOD BY SINGLE EXCITATION SPIN ECHO

摘要

PROBLEM TO BE SOLVED: To provide a clear image at a high speed in an MRI by locating a measured object in the static magnetic field, and applying the inclined magnetic field G constant timewise in the direction (x) or the direction (y) in the orthogonal coordinate system and the RF waves having the resonance frequencies corresponding to many points (w) in the direction (z) as excitation pulses. SOLUTION: A living body 4 is located in the magnet of the static magnetic field, the RF wave with the resonance frequencyνi is radiated to the static electric field and the inclined magnetic field, and the strength of the inclined magnetic field is changed to change the resonance frequencyνi. Echo signals resonant with frequenciesν i corresponding to many points (w) in the direction (z) are outputted in response to G (x) given by the space position (x) of the inclined magnetic field constant timewise in the static magnetic field. The echo signal observed to give an effect similar to the change of the resonance frequency obtained by changing G (x) from the resonance frequencies of many points corresponding to regions for imaging the frequencies of the RF waves is Fourier-transformed to obtain a two-dimensional image on the x-z plane.