C232 ゼロフィル拡張FREBAS変換法によるMR画像のS/N改善

When two methods of solving the Fresnel transform signal are combined and used, a band splitted image is obtained under a certain condition.An image having improved SIN is obtained by applying a noise elimination filter in this band splitted image space and by reconstructing image from the denoised Fresnel transform signal. The method which uses the "method 1" for forming the Fresnel transform signal from the MR image and uses the "method 2" for obtaining the band splitted image is called the Modified FREBAS method. In the Modified FREBAS method, if the surroundings of the formed Fresnel transform signal by the method 1 is filled with zero and applied the method 2 for obtaining the band splitted image, some noise diffuse to the area where zeros are supplemented. The SIN improved image is obtained by the zerofilling Modified FREBAS method by removing the noise with using the Wiener filter in the band splitted image space and by reconstructing after returning to the Fresnel signal space through tracing the reverse-process.