| 摘要 |
PURPOSE: An MRI(Magnetic Resonance Imaging) apparatus is provided to measure the offset voltage and gain of a DAC, and to correct waveform data using the measured results. CONSTITUTION: A digital processing unit(21) calculates a gradient magnetic field and RF waveform. First, second DACs(22,23) convert the gradient magnetic field data and RF waveform data from the digital processing unit(21) into analog signals. A gradient magnetic field amp(24) amplifies the gradient magnetic field waveform from the first DAC(22). A modulator(25) modulates the RF waveform from the second DAC(23). An RF amp(26) amplifies the RF signal from the modulator. An RF transmission coil(27) receives the RF signal from the RF amp(26) to transmit the RF signal. A gradient magnetic field coil(28) receives the output from the gradient magnetic field amp(24) to generate a gradient magnetic field. First, second correctors(22b,23b) respectively correct the digital inputs of the first, second DACs(22,23) so as to offset the results of first/second gain/offset voltage meters(22a,23a).
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