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US 2009/0021256 A1Published application
High frequency coil and magnetic resonance imaging apparatus
AssigneeHitachi, Ltd.
InventorsYoshihisa Soutome, Hideta Habara, Yoshitaka Bito
Life of this patent
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Abstract
To provide an RF coil of an MRI apparatus and improve the irradiation efficiency and the reception sensitivity of a circular polarized magnetic field with a simple structure. An RF coil has a set of input/output terminals and two loops. The two loops are disposed and capacitors in the loops are adjusted so that the linearly polarized magnetic fields generated and detected by the loops are perpendicular to each other, and the combined magnetic field of the linearly polarized magnetic fields is a circular polarized magnetic field.
Claims22
A high frequency coil for a magnetic resonance imaging apparatus, comprising:
- a first loop part made of a conductor including a first capacitor and a second capacitor;
- a second loop part made of a conductor including a third capacitor and a fourth capacitor;
- an input/output terminal composed of a first terminal and a second terminal;
- a first joint part that connects said first loop part and said first terminal to each other;
- a second joint part that connects said second loop part and said second terminal to each other;
- and
- a third joint part that connects said first loop part and said second loop part to each other,
- wherein said first joint part and said third joint part are disposed on the opposite ends of said second capacitor, and said second joint part and said third joint part are disposed on the opposite ends of said fourth capacitor, and
- said first loop part and said second loop part are disposed in such a manner that there is an area in which the direction of a high frequency magnetic field (a first high frequency magnetic field) detected or generated by said first loop part and the direction of a high frequency magnetic field (a second high frequency magnetic field) detected or generated by said second loop part are perpendicular to each other.
6 more elements
A high frequency coil, comprising:
- a first high frequency coil that transmits a high frequency magnetic field to an examinee;
- and
- a second high frequency coil that receives a magnetic resonance signal generated by the examinee,
- wherein at least one of said first high frequency coil and said second high frequency coil is the high frequency coil comprising:a first loop part made of a conductor including a first capacitor and a second capacitor;
- a second loop part made of a conductor including a third capacitor and a fourth capacitor;
- an input/output terminal composed of a first terminal and a second terminal;
- a first joint part that connects said first loop part and said first terminal to each other;
- a second joint part that connects said second loop part and said second terminal to each other;
- and a third joint part that connects said first loop part and said second loop part to each other, wherein said first joint part and said third joint part are disposed on the opposite ends of said second capacitor, and said second joint part and said third joint part are disposed on the opposite ends of said fourth capacitor, and said first loop part and said second loop part are disposed in such a manner that there is an area in which the direction of a high frequency magnetic field (a first high frequency magnetic field) detected or generated by said first loop part and the direction of a high frequency magnetic field (a second high frequency magnetic field) detected or generated by said second loop part are perpendicular to each other, and each of said first high frequency coil and said second high frequency coil is provided with magnetic coupling preventing means that prevents magnetic coupling.
6 more elements
A magnetic resonance imaging apparatus, comprising:
- static magnetic field applying means that applies a static magnetic field to an examinee;
- and
- a coil unit disposed close to a surface of said examinee,
- wherein said coil unit is the high frequency coil comprising:a first loop part made of a conductor including a first capacitor and a second capacitor;
- a second loop part made of a conductor including a third capacitor and a fourth capacitor;
- an input/output terminal composed of a first terminal and a second terminal;
- a first joint part that connects said first loop part and said first terminal to each other;
- a second joint part that connects said second loop part and said second terminal to each other;
- and a third joint part that connects said first loop part and said second loop part to each other, wherein said first joint part and said third joint part are disposed on the opposite ends of said second capacitor, and said second joint part and said third joint part are disposed on the opposite ends of said fourth capacitor, and said first loop part and said second loop part are disposed in such a manner that there is an area in which the direction of a high frequency magnetic field (a first high frequency magnetic field) detected or generated by said first loop part and the direction of a high frequency magnetic field (a second high frequency magnetic field) detected or generated by said second loop part are perpendicular to each other, and said coil unit is disposed in such a manner that said coil unit generates a circular polarized magnetic field rotating clockwise viewed in the opposite direction of said static magnetic field in said examinee or detects a circular polarized magnetic field rotating clockwise viewed in the opposite direction of said static magnetic field from the inside of said examinee.
6 more elements
A magnetic resonance imaging apparatus, comprising:
- static magnetic field forming means that forms a static magnetic field;
- gradient magnetic field forming means that forms a gradient magnetic field;
- high frequency magnetic field forming means that forms a high frequency magnetic field;
- a transmit coil that applies said high frequency magnetic field to an inspection target;
- a receive coil that detects a magnetic resonance signal from the inspection target;
- signal processing means that processes the magnetic resonance signal detected by said receive coil;
- and
- control means that controls said gradient magnetic field forming means, said high frequency magnetic field forming means and said signal processing means,
- wherein at least one of said transmit coil and said receive coil is the high frequency coil comprising:a first loop part made of a conductor including a first capacitor and a second capacitor;
- a second loop part made of a conductor including a third capacitor and a fourth capacitor;
- an input/output terminal composed of a first terminal and a second terminal;
- a first joint part that connects said first loop part and said first terminal to each other;
- a second joint tart that connects said second loop part and said second terminal to each other;
- and a third joint part that connects said first loop part and said second loop part to each others wherein said first joint part and said third joint part are disposed on the opposite ends of said second capacitor, and said second joint part and said third joint part are disposed on the opposite ends of said fourth capacitor, and said first loop part and said second loop part are disposed in such a manner that there is an area in which the direction of a high frequency magnetic field (a first high frequency magnetic field) detected or generated by said first loop part and the direction of a high frequency magnetic field (a second high frequency magnetic field) detected or generated by said second loop part are perpendicular to each other in which said first capacitor and said third capacitor are each replaced with magnetic coupling preventing means that prevents magnetic coupling.
11 more elements
A magnetic resonance imaging apparatus, comprising:
- static magnetic field forming means that forms a static magnetic field;
- gradient magnetic field forming means that forms a gradient magnetic field;
- high frequency magnetic field forming means that forms a high frequency magnetic field;
- a transmit-receive coil that applies said high frequency magnetic field to an inspection target and detects a magnetic resonance signal from the inspection target;
- receiving means that receives said magnetic resonance signal;
- and
- control means that controls said gradient magnetic field forming means, said high frequency magnetic field forming means and said receiving means,
- wherein said transmit-receive coil is the high frequency coil comprising:a first loop part made of a conductor including a first capacitor and a second capacitor;
- a second loop part made of a conductor including a third capacitor and a fourth capacitor;
- an input/output terminal composed of a first terminal and a second terminal;
- a first joint part that connects said first loop part and said first terminal to each other;
- a second joint part that connects said second loop part and said second terminal to each other;
- and a third joint part that connects said first loop part and said second loop part to each other, wherein said first joint part and said third joint part are disposed on the opposite ends of said second capacitor, and said second joint part and said third joint part are disposed on the opposite ends of said fourth capacitor, and said first loop part and said second loop part are disposed in such a manner that there is an area in which the direction of a high frequency magnetic field (a first high frequency magnetic field) detected or generated by said first loop part and the direction of a high frequency magnetic field (a second high frequency magnetic field) detected or generated by said second loop part are perpendicular to each other.
10 more elements
Dependencies are inferred from the claim text.