Abstract: A magnetic resonance system has a receiver designed to receive and evaluate a pilot tone signal and a magnetic resonance signal at the same time. The receiver additionally has a frequency-dependent attenuator to attenuate a received pilot tone signal relative to a received magnetic resonance signal.

Abstract: A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole.

Abstract: A local coil control apparatus and a wireless local coil in a magnetic resonance imaging system. The apparatus includes a control signal transmission unit, the control signal transmission unit including a wireless receiving unit, a control signal extraction unit, and a control signal distribution unit. The wireless receiving unit receives, by a receiving antenna, a signal from a radiofrequency power amplifier emitted by a body coil of the MRI system, and transmits the signal to the control signal extraction unit; the control signal extraction unit, if it detects that the signal is background noise, generates a control signal instructing a local coil unit to switch to a tuned state, and, if it detects that the signal is broadband noise, generates a control signal instructing the local coil unit to switch to a detuned state, and distributes the control signal to each local coil unit through the control signal distribution unit.

Abstract: A coil unit decoupling device and a magnetic resonance system. The device comprises a first phase shift circuit, a second phase shift circuit and a first crossover element, and the first crossover element is a capacitor or inductor, wherein a first connecting end of the first phase shift circuit is connected with a first port of a first coil unit, a second connecting end of the first phase shift circuit is connected with a first connecting end of the first crossover element, a first connecting end of the second phase shift circuit is connected with a first port of a second coil unit, a second connecting end of the second phase shift circuit is connected with a second connecting end of the first crossover element, and the first coil unit and the second coil unit are located in a magnetic resonance system.

Abstract: The disclosure relates to a magnetic resonance imaging device configured to exert a high-frequency electromagnetic field on an object under test in a static magnetic field and to reconstruct an image based on magnetic resonance signals. The magnetic resonance imaging device comprises a receiving coil comprising a plurality of receiving coil elements and configured to receive magnetic resonance signals and feed the magnetic resonance signals to a receiver, and a coupler configured to be coupled with at least a first receiving coil element of the receiving coil, the coupler being directionally coupled with at least the receiver, the first receiving coil element being configured to receive a high-frequency electromagnetic wave signal through the coupler. The directional coupling between the coupler and the receiver is so regulated that the first receiving coil element transmits the high-frequency electromagnetic wave signal to the object under test to sense a physiological movement signal.

Abstract: A coil interface apparatus may include: a plug, for connection to a coil apparatus for receiving a magnetic resonance signal via a test subject in the MRI device. The plug may include a first power coupler and at least one first signal coupler. The apparatus may include a socket, for connection to a main body of the MRI device. The socket may include a second power coupler and at least one second signal coupler. The at least one first signal coupler may send a magnetic resonance signal received from the coil apparatus to the at least one second signal coupler by induction. The at least one second signal coupler may receive the sent magnetic resonance signal by induction. The second power coupler may send a power signal to the first power coupler by induction, and the first power coupler may receive the sent power signal.

Abstract: A local coil may include: a wireless power receiver, for converting electrical energy to AC electricity, the electrical energy being wirelessly received from a power source; an AC-DC converter, for converting the AC electricity to first DC electricity having a first voltage; a DC-DC converter, for converting the first DC electricity to second DC electricity having a second voltage; a comparator, for comparing the first voltage and the second voltage, and generating a level signal on the basis of a comparison result; and a transmitter, for sending the level signal to the power source, such that the power source adjusts an output power of the electrical energy on the basis of the level signal. The wirelessly supplying of power to a local coil as well as power feedback control is achieved to advantageously increase energy transmission efficiency and system robustness.

Abstract: A method and apparatus are provided for limiting a B1 field used for magnetic resonance imaging (MRI). The techniques described herein reduce a waste of performance of the B1 field while ensuring patient safety and improving the MR imaging quality.

Abstract: A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole.

Abstract: A coil decoupling method for a magnetic resonance imaging device, including: sending an instruction causing a transmitter to send a transmitted signal, acquiring a received signal received by a receiver, wherein the received signal is a signal arriving at the receiver after the transmitted signal passes through two coils to be adjusted of a plurality of coils, determining the coupling value between the two coils to be adjusted based on the transmitted signal and the received signal, and sending an instruction for adjusting a decoupling component based on the coupling value.

Abstract: A coil unit decoupling device and a magnetic resonance system. The device comprises a first phase shift circuit, a second phase shift circuit and a first crossover element, and the first crossover element is a capacitor or inductor, wherein a first connecting end of the first phase shift circuit is connected with a first port of a first coil unit, a second connecting end of the first phase shift circuit is connected with a first connecting end of the first crossover element, a first connecting end of the second phase shift circuit is connected with a first port of a second coil unit, a second connecting end of the second phase shift circuit is connected with a second connecting end of the first crossover element, and the first coil unit and the second coil unit are located in a magnetic resonance system.

Abstract: A local coil may include: a wireless power receiver, for converting electrical energy to AC electricity, the electrical energy being wirelessly received from a power source; an AC-DC converter, for converting the AC electricity to first DC electricity having a first voltage; a DC-DC converter, for converting the first DC electricity to second DC electricity having a second voltage; a comparator, for comparing the first voltage and the second voltage, and generating a level signal on the basis of a comparison result; and a transmitter, for sending the level signal to the power source, such that the power source adjusts an output power of the electrical energy on the basis of the level signal. The wirelessly supplying of power to a local coil as well as power feedback control is achieved to advantageously increase energy transmission efficiency and system robustness.

Abstract: The disclosure relates to a magnetic resonance imaging device configured to exert a high-frequency electromagnetic field on an object under test in a static magnetic field and to reconstruct an image based on magnetic resonance signals. The magnetic resonance imaging device comprises a receiving coil comprising a plurality of receiving coil elements and configured to receive magnetic resonance signals and feed the magnetic resonance signals to a receiver, and a coupler configured to be coupled with at least a first receiving coil element of the receiving coil, the coupler being directionally coupled with at least the receiver, the first receiving coil element being configured to receive a high-frequency electromagnetic wave signal through the coupler. The directional coupling between the coupler and the receiver is so regulated that the first receiving coil element transmits the high-frequency electromagnetic wave signal to the object under test to sense a physiological movement signal.

Abstract: In an RF power calculation apparatus and method for an MRI system, a first power calculation processor calculates a first power of an RF signal received by a first receiving method, a second power calculation processor calculates a second power of the RF signal received by a second receiving method, a difference calculation processor calculates the difference between the first power and second power, an RF power calculation processor calculates an RF power of the RF signal on the basis of the first power and second power when the difference is smaller than a first threshold.

Abstract: A debugging device for a body coil of a magnetic resonance imaging (MRI) system includes a pair of output ports connected to a pair of input ports of the body coil. The debugging device also includes a pair of input ports connected to a pair of output ports of the MRI system. The debugging device includes a pair of extension circuits, separately connected between the pair of input ports and the pair of output ports; and a first adjustment capacitor for reducing or eliminating coupling between the pair of input ports. The first adjustment capacitor is bridged between the pair of input ports, and the capacitance of the first adjustment capacitor is variable.

Abstract: In an RF power calculation apparatus and method for an MRI system, a first power calculation processor calculates a first power of an RF signal received by a first receiving method, a second power calculation processor calculates a second power of the RF signal received by a second receiving method, a difference calculation processor calculates the difference between the first power and second power, an RF power calculation processor calculates an RF power of the RF signal on the basis of the first power and second power when the difference is smaller than a first threshold.

Abstract: A debugging device for a body coil of a magnetic resonance imaging (MRI) system includes a pair of output ports connected to a pair of input ports of the body coil. The debugging device also includes a pair of input ports connected to a pair of output ports of the MRI system. The debugging device includes a pair of extension circuits, separately connected between the pair of input ports and the pair of output ports; and a first adjustment capacitor for reducing or eliminating coupling between the pair of input ports. The first adjustment capacitor is bridged between the pair of input ports, and the capacitance of the first adjustment capacitor is variable.