Local coil and magnetic resonance imaging system
View Patent ↗A local coil and a magnetic resonance imaging system are provided. The local coil includes an antenna part, an adjustment part and a transmission part. The antenna part includes a first capacitor connected in series for adjusting a frequency of the antenna part. The adjustment part includes a tuning/detuning diode and is connected in parallel to the first capacitor, and the tuning/detuning diode is used for adjusting tuning and detuning of the antenna part. The transmission part includes a radio-frequency transmission line that connects the antenna part and the adjustment part, and the transmission part provides a phase difference of an odd multiple of 180° between the antenna part and the tuning/detuning diode.
1. A local coil comprising:
an antenna part;
an adjustment part; and
a transmission part,
wherein the antenna part comprises a first capacitor connected in series to a second capacitor, the first capacitor for adjusting a frequency of the antenna part,
wherein the first capacitor comprises a varactor diode,
wherein the adjustment part comprises a tuning/detuning diode and is connected in parallel to the second capacitor, and the tuning/detuning diode is operable to adjust tuning and detuning of the antenna part,
wherein the adjustment part is moved to a position away from the antenna part,
wherein the adjustment part further comprises a voltage divider for adjusting the voltage across the varactor diode,
wherein the voltage divider is a resistance voltage divider connected in parallel to the tuning/detuning diode, and
wherein the transmission part comprises a radio-frequency transmission line that connects the antenna part and the adjustment part, and the transmission part provides a phase difference of an odd multiple of 180° between the antenna part and the tuning/detuning diode.
2. The local coil of claim 1 , wherein the transmission part further comprises a phase converter connected between the radio-frequency transmission line and the tuning/detuning diode.
3. The local coil of claim 2 , wherein the phase converter is a π-shaped or T-shaped phase conversion circuit.
4. The local coil of claim 1 , wherein the first capacitor further comprises a fixed value capacitor connected in parallel to the varactor diode.
5. The local coil of claim 1 , wherein the second capacitor is configured for adjusting a matching impedance flexible housing of the antenna part; and
a fuse is connected in series to the first capacitor.
6. The local coil of claim 1 , wherein the antenna part further comprises a flexible housing.
7. A magnet resonance imaging system comprising:
a local coil comprising:
an antenna part;
an adjustment part; and
a transmission part,
wherein the antenna part comprises a first capacitor connected in series to a second capacitor, the first capacitor for adjusting a frequency of the antenna part,
wherein the first capacitor comprises a varactor diode,
wherein the adjustment part comprises a tuning/detuning diode and is connected in parallel to the second capacitor, and the tuning/detuning diode is operable to adjust tuning and detuning of the antenna part,
wherein the adjustment part is positioned away from the antenna part,
wherein the adjustment part further comprises a voltage divider for adjusting the voltage across the varactor diode,
wherein the voltage divider is a resistance voltage divider connected in parallel to the tuning/detuning diode, and
wherein the transmission part comprises a radio-frequency transmission line that connects the antenna part and the adjustment part, and the transmission part provides a phase difference of an odd multiple of 180° between the antenna part and the tuning/detuning diode.
8. The magnet resonance imaging system of claim 7 , wherein the transmission part further comprises a phase converter connected between the radio-frequency transmission line and the tuning/detuning diode.
9. The magnet resonance imaging system of claim 8 , wherein the phase converter is a π-shaped or T-shaped phase conversion circuit.
10. The magnet resonance imaging system of claim 7 , wherein the first capacitor further comprises a fixed value capacitor connected in parallel to the varactor diode.
11. The magnet resonance imaging system of claim 7 , wherein the second capacitor is configured for adjusting a matching impedance flexible housing of the antenna part; and
a fuse is connected in series to the first capacitor.
12. The magnet resonance imaging system of claim 7 , wherein the antenna part further comprises a flexible housing.