| 摘要 |
<p>Compensation is provided for a gradient field of an NMR imaging system which compensates for the effects of eddy fields developed in the static magnetic field from metallic components during gradient field switching. The compensation comprises providing current overshoot to the gradient coil during gradient switching. The overshoot current decays with a time constant chosen to substantially offset the decay of eddy fields following gradient switching. In a preferred embodiment, a time constant network representative of eddy field decay is coupled in combination with a feedback signal from a current sampling resistor of the gradient coil.</p> |
