Abstract: A magnetic resonance examination system includes an RF arrangement with an RF antenna to acquire magnetic resonance signals from an object to be examined. A motion sensing arrangement detects motion information of the object. The motion sensing arrangement is provided with one or more RF antenna motion sensors mounted on the RF antenna and one or more object motion sensors to be attached to the object. In an example the motion sensors are integrated devices having motion sensitivity along three independent axes.

Abstract: The invention relates to an electrical power distribution apparatus (100) connectible to one or more loads (119). The electrical power distribution apparatus (100) comprises inter alia one or more taps (112) for supplying the loads (119) with electrical power. On top of circuit breakers (108) to switch off the power supply in order to protect the loads against damage, there is also arranged a second layer of soft fuse switches (110) which are arranged to switch on or off the power supply at the taps (112) to control distribution of the power. The soft fuses (110) operate in dependence on and in response to commands issued from a controller (105) which in turn operates and issues those commands in response to and independence on the voltages and amperages monitored at those taps (112) by way of a monitoring module (111). Switching on/off occurs at amperage and voltages lower than the critical threshold values to which the circuit breakers (108) respond to.

Abstract: A light data communication link device (50) for use in a magnetic resonance examination system (10) comprises a first light emitter and receiver unit (52) and a second light emitter and receiver unit (76). A light generating member (54), a first optical waveguide (62) and a light diffuser (58) of the first light emitter and receiver unit (52), a distance in space between the light diffuser (58) and a converging lens (84) of the second light emitter and receiver unit (76), and the converging lens (84), a second optical waveguide (88) and a light receiving member (80) of the second light emitter and receiver unit (76) form a first optical pathway (90) for data communication.

Abstract: An active position marker system comprising at least one active position marker (10) and a remote transceiver unit (20) for communicating with the position marker is disclosed. Basically, the position marker (10) comprises a local RF receive coil (11) for receiving MR signals which are excited in a local volume, and a parametric amplifier (14) for amplifying and upconverting the frequency of the received MR signal into at least one microwave sideband frequency signal. This microwave signal is transmitted wirelessly or wire-bound to the transceiver unit for downconverting the same and supplying it to an image processing unit of an MR imaging apparatus.

Abstract: A power supply unit (130) powers at least one gradient coil (128) of a magnetic resonance (MR) examination system (110) with a main magnet (114) having, in at least one state of operation, a substantially static magnetic field strength, and with an MR measurement signal bandwidth. The power supply unit (130) includes a switched-mode power converter (134) for powering the at least one gradient coil (128), and including at least one switching member provided to switch between a conducting state configuration and an essentially non-conducting state configuration at a first fundamental switching frequency (fSW). A pulse control unit (132) is designed to provide switching pulses at the first fundamental switching frequency (fSW) for controlling the switching of the at least one switching member. Upon triggering by a trigger signal (142), the pulse control unit (132) is provided to change the first fundamental switching frequency (fSW) to at least a second fundamental switching frequency (fSW).

Abstract: A light data communication link device (50) for use in a magnetic resonance examination system (10) comprises a first light emitter and receiver unit (52) and a second light emitter and receiver unit (76). A light generating member (54), a first optical waveguide (62) and a light diffuser (58) of the first light emitter and receiver unit (52), a distance in space between the light diffuser (58) and a converging lens (84) of the second light emitter and receiver unit (76), and the converging lens (84), a second optical waveguide (88) and a light receiving member (80) of the second light emitter and receiver unit (76) form a first optical pathway (90) for data communication.

Abstract: A magnetic resonance imaging system (402, 500) includes magnetic field gradient coils (516), a gradient coil power supply (320, 424, 518), a processor (540), and a chiller (308, 526) for providing the coolant to the gradient coils. The magnetic resonance imaging system further includes a memory (546) for storing machine executable instructions (580, 582, 584, 586, 588, 590, 592). The instructions cause the processor to receive (100, 200) a pulse sequence (550), to generate (102, 202) the chiller control signals using the pulse sequence and a chiller thermal model (582) of the gradient coils and the coolant reservoir, and to send (104, 206) the chiller control signals to the chiller. The chiller control signals cause the chiller to halt chilling at least a portion of the time when the gradient coil power supply supplies current to the magnetic field gradient coils.

Abstract: An magnetic resonance examination system comprises an RF arrangement with an RF antenna to acquire magnetic resonance signals from an object to be examined, and a motion sensing arrangement to detect motion information of the object. The motion sensing arrangement is provided with one or more RF antenna motion sensors mounted on the RF antenna and one or more object motion sensors to be attached to the object. In an example the motion sensors are integrated devices having motion sensitivity along three independent axes.

Abstract: A power supply unit (130) for powering at least one gradient coil (128) of a magnetic resonance (MR) examination system (110) with a main magnet (114) having, in at least one state of operation, a substantially static magnetic field strength, and with an MR measurement signal bandwidth, the power supply unit (130) comprising: a switched-mode power converter (134) for powering the at least one gradient coil (128), comprising at least one switching member provided to switch between a conducting state configuration and an essentially non-conducting state configuration at a first fundamental switching frequency (fSW); a pulse control unit (132) designed to provide switching pulses at the first fundamental switching frequency (fSW) for controlling the switching of the at least one switching member; wherein, upon triggering by a trigger signal (142), the pulse control unit (132) is provided to change the first fundamental switching frequency (fSW) to at least a second fundamental switching frequency (fSW).

Abstract: An active position marker system comprising at least one active position marker (10) and a remote transceiver unit (20) for communicating with the position marker is disclosed. Basically, the position marker (10) comprises a local RF receive coil (11) for receiving MR signals which are excited in a local volume, and a parametric amplifier (14) for amplifying and upconverting the frequency of the received MR signal into at least one microwave sideband frequency signal. This microwave signal is transmitted wirelessly or wire-bound to the transceiver unit for downconverting the same and supplying it to an image processing unit of an MR imaging apparatus.

Abstract: A radio frequency (RF) shield for use in a magnetic resonance imaging (MRI) scanner, the RF shield comprising a carrier (22) and a plurality of nanoparticles (24) which—are immovably connected to the carrier (22),—are aligned along a direction (26) in space, and—have an anisotropic electrical conductivity in the direction (26) in space.

Abstract: The invention relates to a nuclear magnetic resonance imaging apparatus comprising: a main magnet (122) adapted for generating a main magnetic field; at least one radio frequency receiver coil unit (144) for acquiring magnetic resonance signals in a receiver coil radio frequency band (202) from an examined object (124); means (140) for inductively (wirelessly) supplying electric power to an electric component of the apparatus, wherein the electric component is adapted to be powered by inductively supplied electric power, wherein the power transfer frequency (200) and the higher-harmonics (206) of the power transfer frequency (200) for inductively supplying the electric power are located outside the receiver coil radio frequency band (202).

Abstract: The invention relates to a RF reception antenna device (10) for receiving MR signals in a MR imaging system. The device (10) comprises a RF resonant circuit including a RF reception antenna (15) for picking up the MR signals, and a RF amplifier (17) connected at its input to the RF resonant circuit for amplifying the picked up MR signals. The invention proposes to make provision for a detection circuit (18) configured to derive a switching signal from an output signal of the RF amplifier (17). A switching circuit (19) is responsive to the switching signal, wherein the switching circuit (19) is configured to switch the RF resonant circuit between a resonant mode and a non-resonant (i.e. detuned) mode.

Abstract: A magnetic resonance imaging system (402, 500) with magnetic field gradient coils (516) and a gradient coil power supply (320, 424, 518). The magnetic resonance imaging system further comprises a processor (540) and a chiller (308, 526) for providing the coolant to the gradient coils. The magnetic resonance imaging system further comprises a memory (546) for storing machine executable instructions (580, 582, 584, 586, 588, 590, 592). The instructions cause the processor to receive (100, 200) a pulse sequence (550), to generate (102, 202) the chiller control signals using the pulse sequence and a chiller thermal model (582) of the gradient coils and the coolant reservoir, and to send (104, 206) the chiller control signals to the chiller. The chiller control signals cause the chiller to halt chilling at least a portion of the time when the gradient coil power supply supplies current to the magnetic field gradient coils.

Abstract: A magnetic resonance system includes a wireless local coil which functions as a transmit only or a transmit and receive coil. The local coil includes an RF coil with a plurality of coil elements. A corresponding number of transmit amplifiers apply RF signals to the RF coil elements to transmit an RF signal. A peak power supply provides electrical power to the transmit amplifiers to transmit relatively high power RF pulses. A trickle charging device recharges the peak power supply between RF pulses front a local coil power supply. A power transfer device wirelessly transfers power to a coil power supply recharging device which recharges the local coil power supply.

Abstract: A data rate controlling feedback loop evaluates an actual instantaneous available quality of service of a communication link for transmitting data and controls the data rate based on an evaluation result, Feedback control may both be local to a device for acquiring examination data, such as a magnetic resonance imaging coil, or over the communication link by reducing the data rate at least momentarily to fit the communication link's performance over time, enabling a graceful degradation of an image quality at lower data rates.

Abstract: The invention relates to a RF reception antenna device (10) for receiving MR signals in a MR imaging system. The device (10) comprises a RF resonant circuit including a RF reception antenna (15) for picking up the MR signals, and a RF amplifier (17) connected at its input to the RF resonant circuit for amplifying the picked up MR signals. The invention proposes to make provision for a detection circuit (18) configured to derive a switching signal from an output signal of the RF amplifier (17). A switching circuit (19) is responsive to the switching signal, wherein the switching circuit (19) is configured to switch the RF resonant circuit between a resonant mode and a non-resonant (i.e. detuned) mode.

Abstract: A method and an arrangement for uni- or bidirectional wireless communication of signals or data especially in a reflective environment like a MR imaging system, between at least one first transmitter and/or receiver unit (501, 601, 701; T/R1) and at least one second transmitter and/or receiver unit (801; T/R2) is disclosed. The reliability and availability of the communication link especially in a highly reflective environment is improved especially by using spread spectrum technology and ultra wide band carrier frequencies.

Abstract: The invention relates to an electrical power distribution apparatus (100) connectible to one or more loads (119). The electrical power distribution apparatus (100) comprises inter alia one or more taps (112) for supplying the loads (119) with electrical power. On top of circuit breakers (108) to switch off the power supply in order to protect the loads against damage, there is also arranged a second layer of soft fuse switches (110) which are arranged to switch on or off the power supply at the taps (112) to control distribution of the power. The soft fuses (110) operate in dependence on and in response to commands issued from a controller (105) which in turn operates and issues those commands in response to and independence on the voltages and amperages monitored at those taps (112) by way of a monitoring module (111). Switching on/off occurs at amperage and voltages lower than the critical threshold values to which the circuit breakers (108) respond to.

Abstract: The present invention relates to a data rate controlling feedback loop (355, 360) that can evaluate an actual instantaneous available quality of service of a communication link (345) for transmitting data and control the data rate based on an evaluation result. Feedback control may both be local to a device for acquiring examination data such as e.g. a magnetic resonance imaging coil or over the communication link by reducing the data rate at least momentarily to fit the communication link's performance over time, enabling a graceful degradation of an image quality at lower data rates.