How to design the gradient coil assembly of the MRI with the continuously variable field of view, the image forming apparatus, a gradient coil system for an image forming system and an image forming method

摘要

The gradient coil assembly (22), substantially zero and a set of base gradient coil for generating a magnetic field gradients through the main magnetic field of a magnetic resonance imaging apparatus for generating a magnetic field gradient is approximately linear in the effective imaging volume of the first I comprises a set of correction gradient coil for generating a magnetic field gradient having a first moment is. In order to generate a magnetic field gradient is approximately linear in the effective image the second volume different from the effective imaging volume of the first set of correction gradient coils, tertiary that bind to high-order terms of the set of base gradient coil and I will produce a moment of higher order. In a preferred embodiment of the present invention, the second volume is continuously variable by adjusting the amount of current applied to the correction coil and coil base.