The gradient amplifier is an essential equipment of Magnetic Resonance Imaging system (MRI). It supplies the gradient coils with pulse currents according to the signal from the control system.
The phase mapping method of a field inhomogeneity based on an Z axis pulse field gradient and polynomial fitting procedures of the axial shimming coil currents were described.
通过对Z轴磁场梯度和匀场线圈电流的多项式拟合，以获得磁场不均匀而引起的相位分布。
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The desired fast rise of the gradient magnetic filed is suppressed by the eddy currents so that the imaging process is affected.