Abstract: The invention relates to electrophysiology catheter systems and their use, such as in an MRI environment, and in particular to analysis of electric signals from such. An electrophysiology (EP) catheter with a plurality of electrically isolated electrode segments arranged in longitudinally spaced bands around the catheter is used to detect electric signals. A workstation receives the electrical signals which are then processed by a processing unit. Electric signals from electrode segments can be used to determine roll angle information of the catheter in relation to patient anatomy by determining signals from electrode segments in contact with tissue. Also, electric signals can be used to extract a reference signal that can be used to correct for gradient induced artifacts.

Abstract: The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch.

Abstract: The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch.

Abstract: An RF-safe interventional or a non-interventional instrument is used during an MR imaging or MR examination of an examination object (A). The instrument is made of or includes at least one longitudinal or elongated electrically conductive element (1, 3), for example, in the form of a conductor or wire or line for feeding electrical signals, or in the form of the instrument itself or a component or a part thereof, which is not provided for feeding electrical signals but is nevertheless electrically conductive. All such elements are subject to RF common mode currents which are induced in the element when the instrument or element is exposed to an RF/MR excitation field generated during MR imaging or MR examination by an MR imaging apparatus. The instrument is made RF-safe by increasing the energy loss of an oscillator which is represented by the conductor (1, 3) by a damping element (4; 6) in order to prevent or limit RF heating of the examination object (A) at or surrounding the conductor (1, 3).

Abstract: The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch.

Abstract: A method of magnetic resolution (MR) imaging of a moving portion of a body of a patient placed in an examination volume of a MR device. For the purpose of enabling improved interventional MR imaging from acquiring a MR signal data with motion compensation, the invention proposes that the method includes repeated acts of collecting tracking data from an interventional instrument introduced into the portion of the body, subjecting the portion of the body to an imaging sequence for acquiring one or more MR signals therefrom, wherein parameters of the imaging sequence are adjusted on the basis of the tracking data, and reconstructing one or more MR images from the MR signal data set.

Abstract: The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch.

Abstract: An RF-safe interventional or a non-interventional instrument is disclosed for use during an MR imaging or MR examination of an examination object (A), which instrument is made of or comprises at least one longitudinal or elongated electrically conductive element (1, 3), especially in the form of a conductor or wire or line for feeding electrical signals, or in the form of the instrument itself or a component or a part thereof, which is not provided for feeding electrical signals but nevertheless electrically conductive, wherein all such elements are subject to RF common mode currents which are induced in the element when the instrument or element is exposed to an RF/MR excitation field generated during MR imaging or MR examination by means of an MR imaging apparatus.

Abstract: A transmission cable including a transmission line, at least two electrically conductive line segments separated by a non-conductive gap, a bridging unit including at least one electrically conductive bridge segment capable of bridging the non-conductive gap, and a switching unit arranged to move the bridging unit and/or the transmission line to electrically connect the two line segments by closing the non-conductive gap using the bridge segment or to electrically disconnect the two line segments by opening the non-conductive gap.

Abstract: An interventional device (12) is configured to be positioned in a body and includes an electrically operable unit (E1, E2) configured to carry out an interaction with the body upon a receipt of electric power. The device further includes a sensor (2) configured for wirelessly receiving electromagnetic energy from a remote source. The sensor is configured as a resonant circuit (2a, 2b) which converts the received electromagnetic energy into the electric power. The electrically operable device may include a diagnostic and/or therapeutic module.

Abstract: An electrically conductive transmission line for transmitting RF signals, in particular for transmitting MR signals between a transmission and/or receiving coil and a transmitting and/or receiving unit, by which separate known matching networks can be avoided or reduced. A transmission line is proposed comprising a plurality of lead segments coupled by transformers having a transformer impedance ZL placed between two neighboring lead segments, wherein for power matching of the two transformers placed at opposite ends of a lead segment, the lead segment has a lead segment impedance Z0 or a dielectric constant ?r and wherein the lead segment has a short length l. Thus, the lead segments themselves provide the matching of the transformers, and separate matching circuits are no longer needed.

Abstract: The present invention relates to a catheter (6) comprising: a connector (65, 66) at a proximal side of the catheter for connecting the catheter to an external signal transmission/receiving unit (10) for transmitting and/or receiving signals, an electrode (63, 64) at a distal side of the catheter, and an electrical connection including an electrical wire (61, 62) for electrically connecting the electrode and the connector for the transmission of signals between the electrode and the connector, wherein the electrical connection has a high electrical resistance of at least 1 k?, in particular of at least 5 k?. Thus, the present invention provides a solution to prevent excessive heating during EP interventions under MR guidance by using highly resistive wires and or lumped resistors as connections within catheters.

Abstract: The invention relates to a dynamic nuclear polarization apparatus (116) for continuous provision of hyperpolarized samples (114) comprising dynamically nuclear polarized nuclear spins, the apparatus (116) comprising a polarization region (106) for polarization of said nuclear spins resulting in said hyperpolarized samples, wherein the apparatus (116) further comprises: a cryostat (102) for cooling the samples (114) in the polarization region (106), a magnet (100) for providing a magnetic field to the cooled samples in the polarization region (106), a radiation source (112) for concurrently to the magnetic field provision providing a nuclear polarizing radiation to the polarization region (106) for receiving the hyperpolarized samples, a sample transport system (104) for continuously receiving unpolarized samples (114), transporting the unpolarized samples to the polarization region (106) for nuclear spin polarization and providing the resulting hyperpolarized samples (114).

Abstract: An apparatus for applying energy within an object includes an energy applying unit having an energy emitting element or outputting energy within the object and an energy storage unit locatable within the object and coupled to the energy emitting element. The apparatus further includes an electrical control line coupled to the energy applying unit for controlling the application of energy within the object by controlling transmission of energy from the energy storage unit to the energy emitting element.

Abstract: An electrically conductive transmission cable for supplying a DC signal safely to an electrical device in the presence of radio-frequency (RF) fields in a magnetic resonance (MR) is disclosed herein. The transmission cable comprises a transmission line (STL) comprising at least a first segment (S1) and a second segment (S2), wherein the first and second segments are electrically connected to each other by a reactive coupling unit (103), and a rectifier unit (101) connected to the transmission line and configured to extract the DC signal (203) from the modulated DC signal (201). The extracted DC signal may be supplied to an electrical device or used for cardiac pacing. The transmission cable finds application in auxiliary devices used in an MR environment, for example an interventional catheter with or without an active tracking circuit (301).

Abstract: The invention relates to a magnetic resonance imaging system comprising a main magnet coil (2) for generating a uniform, steady magnetic field within an examination volume, a number of gradient coils (4, 5, 6) for generating switched magnetic field gradients in different spatial directions within the examination volume, at least one cardiac RF coil (11) for transmitting RF pulses to and/or receiving MR signals from the chest region of a body (10) of a patient positioned in the examination volume, a control unit (13) for controlling the temporal succession of RF pulses and switched magnetic field gradients, and a reconstruction unit (15) for reconstructing a MR image from the MR signals.

Abstract: The present invention relates to a catheter (2) for applying energy to an object (6) and a magnetic resonance imaging system (1) for localizing the catheter (2). The catheter (2) comprises an energy application element for applying energy to the object (6), and a cavity for providing a magnetic resonance fluid from which magnetic resonance signals generated by the magnetic resonance imaging system (1) are receivable, wherein the cavity is adapted for providing a cooling fluid as the magnetic resonance fluid for cooling the energy application element. The catheter (2) comprises further a tracking coil (15) for tracking the catheter (2), wherein the tracking coil (15) is adapted to receive the magnetic resonance signals from the magnetic resonance fluid. Thus, the magnetic resonance fluid fulfils at least two functions, providing magnetic resonance signals for tracking the catheter (2) and cooling the energy application element.

Abstract: A dispenser (132), a magnetic resonance imaging system (100), and a method for using hyperpolarized contrast agent (304) during a magnetic resonance imaging examination. The dispenser comprises an attachment component (136) for a face piece (138). The face piece is adapted for receiving the surface of a subject (114) such that when the subject inhales hyperpolarized contrast agent enters the respiratory system of the subject. The dispenser further comprises a reservoir (300) adapted for receiving the hyperpolarized contrast agent. The dispenser further comprises a gas flow (406) tube connected to the attachment component and a vaporizer (406, 408, 412, 510, 602, 606) for vaporizing the hyperpolarized contrast agent in the gas flow tube into a hyperpolarized vapor. The dispenser further comprises a controller (402) for controlling when the vaporizer vaporizes the hyperpolarized contrast agent.

Abstract: The invention relates to a method of MR imaging of a moving portion (22) of a body (10) of a patient placed in an examination volume of a MR device (1). For the purpose of enabling improved interventional MR imaging with motion compensation, the invention proposes that the method comprises the steps of: a) collecting tracking data from an interventional instrument (19) introduced into the portion (22) of the body (10), b) subjecting the portion (22) of the body (10) to an imaging sequence for acquiring one or more MR signals therefrom, wherein parameters of the imaging sequence are adjusted on the basis of the tracking data, c) acquiring a MR signal data set by repeating steps a) and b) several times, d) reconstructing one or more MR images from the MR signal data set.

Abstract: The invention relates to electrophysiology catheter systems and their use, such as in an MRI environment, and in particular to analysis of electric signals from such. An electrophysiology (EP) catheter with a plurality of electrically isolated electrode segments arranged in longitudinally spaced bands around the catheter is used to detect electric signals. A workstation receives the electrical signals which are then processed by a processing unit. Electric signals from electrode segments can be used to determine roll angle information of the catheter in relation to patient anatomy by determining signals from electrode segments in contact with tissue. Also, electric signals can be used to extract a reference signal that can be used to correct for gradient induced artefacts.