| 摘要 |
PROBLEM TO BE SOLVED: To easily and precisely select a central frequency in an MRI device by taking the latter part from at least the echo center of an echo waveform data, and Fourier-processing the data obtained by doubling the taken data to determine the half spectrum. SOLUTION: In the central frequency selecting processing in an MRI device 100, a fractional echo signal is received by prescreening, an echo waveform data f(x) is multiplied by a half window to form a half data fh(x). The fh(x) is Fouriertransformed to provide a half spectrum H(ω). The f(x) is multiplied by a center window to form a center data F1(x), and this is Fourier-transformed to provide a center spectrum L(ω) The half spectrum is phase-corrected by the phaseθ(ω) of the L(ω), the actual number part is taken as a spectrum S(ω), the peak of waveform of the S(ω) is specified, and its frequency is selected as central frequency.
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