| 摘要 |
PURPOSE:To correct density abnormality appearing at the central part of a picture by defining Fourier transformation by a specified expression, and executing correction to make a value obtained by subtracting average of errors from the 0-frequency component among obtained Fourier components a new 0-frequency component. CONSTITUTION:If picture reconfiguration is defined by the Fourier transformation shown by the expression I when there is an offset occurring in the measurement data of a magnetic resonance device, since 0-frequency data corresponding to the central part of the reconstructed picture corresponds simply to the average value of the measurement data, the offset remains as it is, and the abnormal value of density appears. Besides, N in the expression I is the number of pieces of the data, and f(X), X=0,1,...,N-1 represents a data string. In this case, since the expected value of an error accompanied with bit shift after inversion and addition corresponds to the offset, if the expected value of the error is obtained, the offset can be known. Thus, the density abnormal value of the central part of the picture can be known, and the abnormal value can be corrected. |
