| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of image luminescent spot by convergent noise caused by higher harmonics of a sampling signal in converting AD of a detection signal in an MRI device. SOLUTION: A relation between sampling frequency fs of an AD converter 26 and reference frequency fL generated by a digital synthesizer 21 in receiving is held fL=n×fs/2 so that the convergence position of the higher harmonic components of the sampling frequency fs, which causes a luminescent spot noise, is positioned outside the image at all times. The position of the luminescent spot noise generated on the image can be moved outside the view so that a superior image without affected by the luminescent spot noise can be obtained. The fluctuation in the central frequency of the detection signal caused of magnetic field fluctuation can be solved by fluctuating the waveform table used for an arithmetic device.
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