LOW PROFILE ELECTRICAL SHIM COIL
Publication Date: 2011-Nov-28
The IP.com Prior Art Database
The invention provides an electrical shim coil design on a multilayer of a circuit board. Such a multilayer circuit board may minimize the radial space. Further, the proposed electrical shim coil may fit into the space provided by the wide-bore gradient coil. Moreover, the method may eliminate the winding time for the Z harmonic coils and in addition, increase the speed of the gradient coil assembly process.
FIELD OF INVENTION
The invention generally relates to magnetic resonance imaging (MRI) systems and more particularly to a low profile electrical shim coil design for MRI.
BACKGROUND OF THE INVENTION
Generally, an MRI system comprises gradient coils that produce varying magnetic fields when a current is applied to them. Typically, the gradient coils are designed to produce a magnetic field that is aligned along the z axis and also, varies linearly in amplitude with the position along one of the x, y or z axes. Such MRI systems require a uniform magnetic field. However, inhomogeneities in the magnetic field may be introduced by various factors such as environmental effects, design restrictions, imperfections in the magnet, and so forth. Such inhomogeneities in the magnetic field may adversely affect data acquisition and the image reconstruction. A process known as shimming may be used to remove such inhomogeneities from the magnetic field. Further, an MRI magnet may be shimmed using either active (superconducting or electrical) or passive shim metal.
In conventional wide-bore gradient systems, there is a radial space limitation for an electrical shim coil. Typically, the electrical shim coil is approximately 20 millimetres thick, in addition to the shim cylinder thickness. Such an electrical shim cylinder is inserted between the inner and the outer gradient coils. However, such a design is complicated, costly and labor intensive.
Hence, there exists a need for a simple, cost-effective electrical shim coil design, which may reduce the labor cost and time.
BRIEF DESCRIPTION OF THE INVENTION
The invention provides an electrical shim coil design on a multilayer of a circuit board. Such a multilayer circuit board may minimize the radial space. Also, the proposed electrical shim coil may fit into the space provided by the wide-bore gradient coil.
DETAILED DESCRIPTION OF THE INVENTION
The invention proposes an electrical shim coil design on a multilayer of a circuit board, which may minimize the radial space. The proposed circuit board may be wrapped around the...