Gradient coil and magnetic resonance imaging device
A gradient coil according to an embodiment includes a saddle coil conductor part that is formed of a conductive material to have a substantially cylindrical shape. The conductor part includes a first region on which a spiral shaped first pattern is formed and a second region on which a second pattern different from the spiral shaped first pattern is formed.
1. A gradient coil for a magnetic resonance imaging (MRI) system, said gradient coil comprising:
a saddle-shaped conductor part that is formed of a conductive material to have a cylindrical shape,
wherein the conductor part includes:
a spiral shaped first pattern configured to generate a gradient magnetic field when electrical current from an MRI system gradient magnetic field power supply is conducted there-along, and
a striped second pattern different from the first pattern, the second pattern being formed at a center part inside the first pattern or at outer peripheral corner parts outside the first pattern, the second pattern being configured to be decoupled from generating a gradient magnetic field component used in imaging and electrically disconnected from the first pattern conductor part while said electrical current is supplied to said first pattern conductor part.
2. The gradient coil according to claim 1 , wherein the second pattern is formed of slits parallel to an axis direction of the cylindrical shape so as to reduce eddy currents, Lorentz forces and magnetic field components having adverse influence on imaging.
3. The gradient coil according to claim 1 , wherein the conductor part is a conductive plate on which the first pattern and the second pattern are processed.
4. The gradient coil according to claim 1 , wherein:
the conductor part first pattern and the conductor part second pattern are provided as each of an X coil and a Y coil, and the conductor part first and second patterns of the X coil and of Y coil are respectively laminated and formed to have the cylindrical shape, and resin is impregnated between gaps of the laminated conductor part first and second patterns of the X coil and first and second patterns of the Y coil.
5. The gradient coil according to claim 1 , wherein at least part of an exterior of the cylindrically shaped conductor part is wound with tape in a spiral manner, tape windings being axially spaced along a circumferential direction.
6. The gradient coil according to claim 5 , wherein the tape is separately wound around the conductor part in respectively corresponding plural regions obtained by dividing the cylindrical shape into two or more regions in the axis direction thereof.
7. The gradient coil according to claim 5 , wherein
the conductor part is formed by a plurality of conductive plates arranged in the axis direction of the cylindrical shape, and
the tape is wound around each of the conductive plates.
8. The gradient coil according to claim 5 , wherein the tape is wound on the first and second patterns of the conductor part.
9. A magnetic resonance imaging (MRI) device comprising:
a static magnetic field magnet configured to generate a static magnetic field; and
a gradient coil configured to generate a gradient magnetic field,
wherein
the gradient coil includes a saddle-shaped conductor part that is formed of a conductive material to have a cylindrical shape, and
the conductor part includes:
a spiral shaped first pattern configured to generate the gradient magnetic field when electrical current from an MRI system gradient magnetic field power supply is conducted there-along, and
a striped second pattern different from the first pattern, the second pattern being formed at a center part inside the first pattern or at outer peripheral corner parts outside the first pattern, the second pattern being configured to be decoupled from generating a gradient magnetic field component used in imaging and electrically disconnected from the first pattern conductor part while said electrical current is supplied to said first pattern conductor part.