A new method of decoupling for gradient systems in MRI

摘要

A set of external coils is designed to eliminate the induced voltage in shim coils caused by the changing current in the gradient coils. By placing the external coil near the line which supplies the current for the gradient coil in a certain way and inserting it into the circuit of shim coils, a induced voltage which has the same wave form with the induced voltage in the shim coil is generated and consequently the coupling between the shim coil and the gradient coil is eliminated. Moreover, the induced voltages of various shim coils are simulated and the parameter of one external coil is determined by the result of the simulation.