| 摘要 |
An image reconstruction method in an NMR imaging such as an echo-planar method, a fast Fourier imaging method or a fast spectroscopic imaging method is disclosed in which a spin-echo train is measured by use of an oscillating field gradient to obtain an actual measurement data train having a k-trajectory having positive and negative gradients on a k-space. A desired nuclear spin distribution is produced by establishing a predetermined trial image, subjecting each data in the trial image to a phase shift corresponding to the gradient of the k-trajectory and thereafter subjecting the phase-shifted trial image to inverse Fourier transformation to produce virtual measurement data trains which coincide in coordinates with the actual measurement data train, determining a difference between each data in the virtual measurement data train and the corresponding data in the actual measurement data train and making the sum of the absolute values of all of the differences or the sum of squares of the absolute values of all of the differences, and successively modifying the trial image so that the sum becomes small. |
