Koninklijke Philips Corporation N.v.

Koninklijke Phillips Electronics N.v.

Philips Intellectual Property & Standards Gmbh

Paul Royston Harvey

Johan Samuel Van Den Brink

Zhiyong Zhai

Miha Fuderer

Cornelis Leonardus Gerardus Ham

Michael Andrew Morich

Gordon D DeMeester

Ingmar Graesslin

Nicolaas Bernardus Roozen

Ulrich Wolfgang Katscher

Thomas Hendrik Rozijn

Patrick Willem Paul Limpens

Peter Boernert

Johannes Adrianus Overweg

Gabriele Marianne Beck

Jouke Smink

Romhild Martijn Hoogeveen

Willem Marten Prins

Wilhelmus Reinerius Maria Mens

Gerrit Hendrik Van Yperen

Ferdinand Schweser

Christoph G Leussler

Christian Findeklee

Eberhard Sebastian Hansis

Kay Nehrke

Jochen Keupp

Hanno Heyke Homann

Marinus Johannes Adrianus Maria Van Helvoort

Gerardus Bernardus Jozef Mulder

Tobias Richard Schaeffter

Gerardus Nerius Peeren

Tobias Ratko Voigt

Johannes Ferdinand Van Der Koijk

Sander Slegt

Sven Biederer

Martijn Roger La Grange

Gerardus B J Mulder

Eric Jean

Michael Jozef Duijvestijn

Theo Jenneskens

Dimitrios Pananakis

Andriy Shmatukha

Luc Richard Kruger

Jacob Anne Den Boer

Steve Lorenc

Alfred Hendrik Van Ommen

Gerrit H Ijperen

Wilhelmus R M Mens

Franciscus J M Benschop

Ulrich Katscher

Wen Deng

Bing Wu

Gordon D De Meester

An ultra-high field radio-frequency (RF) transmit/receive apparatus radio-frequency (RF) transmit/receive apparatus for magnetic resonance (MR) systems, may include: a dipole-array based volume coil () with a plurality of straight dipole antennas (); at least three circular conducting rings () radial surrounding the dipole-array based volume coil (), the at least three circular conducting rings () being substantially parallel with each other, having a plurality of ports () for receiving a set of quadrature drive signals, the RF coil apparatus further comprising at least two independent transmit/receive (T/R) RF channels () for driving the dipole-array based volume coil () and the at least three circular conducting rings ().

Magnetic resonance volume coil with multiple independent transmit receive channels

A method of operating a magnetic resonance imaging system () includes adjusting a radio frequency excitation field B1 to be applied to a subject of interest () to be imaged. At least one position parameter (d) that is indicative of a position of at least the portion of the subject of interest () relative to at least one radio frequency transmit antenna () of the magnetic resonance imaging system () is determined. At least one radio frequency power-related parameter of radio frequency power to be fed to the at least one radio frequency transmit antenna () is adjusted in dependence of the at least one of the determined at least one position parameter (d) and a determined geometric dimension (w) of the subject of interest ().

Patient proximity-modulated specific absorption rate

The invention relates to a magnetic resonance imaging (MRI) system with emergency quench. According to the invention, a magnetic resonance imaging system () comprising a superconductive magnet () with windings () for generating a magnetic field, an emergency button () and a circuitry logic () for controlling the magnet () coupled to the magnet () and to the emergency button (), wherein the magnet () is operable in a superconducting state and in a normal conductivity state, respectively, and the emergency button () and the circuitry logic () are configured in such a way that, when the magnet () is operated in the superconducting state, actuating the emergency button () by a user in a predefined first way initiates ramping down the magnetic field while dissipating energy stored in the windings () of the magnet () to an external dissipation device (), and actuating the emergency button () by a user in a predefined second way which is different from the first way initiates quenching the magnetic field by heating up at least part of the windings () of the magnet () leading to a dissipation of energy stored in the windings () of the magnet () as additional heat to the magnet (). In this way, an easy and reliable way to control a superconductive magnet () of an MRI system () is provided in an event in which the magnetic field has to be removed.

Magnetic resonance imaging system with emergency quench

In a magnetic resonance examination system, the patient carrier is mounted moveably in a direction transverse to the support surface and an RF antenna has a fixed geometrical relation to the support surface.

Magnetic resonance examination system with a moveable patient carrier

A therapeutic apparatus comprising a radiotherapy apparatus for treating a target zone and a magnetic resonance imaging system for acquiring magnetic resonance imaging data. The radiotherapy apparatus comprises a radiotherapy source for directing electromagnetic radiation into the target zone. The radiotherapy apparatus is adapted for rotating the radiotherapy source at least partially around the magnetic resonance magnet. The magnetic resonance imaging system further comprises a radio-frequency transceiver adapted for simultaneously acquiring the magnetic resonance data from at least two transmit-and-receive channels. The therapeutic apparatus further comprises a processor and a memory containing machine executable instructions for the processor. Execution of the instructions causes the processor to: calibrate the transmit-and-receive channels; acquire the magnetic resonance data; reconstruct a magnetic resonance image; register a location of the target zone in the image; and generate radiotherapy control signals using the registered image.

Magnetic resonance imaging and radiotherapy apparatus with at least two-transmit-and receive channels

The invention provides for a magnetic resonance imaging system () comprising: a magnet () for generating a main magnetic field with an imaging zone (), and a gradient coil system (). The gradient coil system comprises a set of unshielded gradient coils (). The magnetic resonance imaging system further comprises a processor () for controlling the magnetic resonance imaging system. Execution of the instructions stored in a memory cause the processor to: acquire () imaging magnetic resonance data () from a volume () within the imaging zone using a zero echo time pulse sequence; reconstruct () a three-dimensional image () using the imaging magnetic resonance data; subtract a calibration image from the three-dimensional image, the calibration image having been acquired without a subject in the imaging zone; and render the three-dimensional image on a display by projecting it on a two-dimensional plane.

Magnetic resonance imaging using zero echo time puse sequences

The invention provides for a magnetic resonance imaging system () for acquiring magnetic resonance data () from an imaging zone (). Execution of the instructions causes a processor () controlling the MRI system to: acquire () imaging magnetic resonance data () with radio frequency excitation of the radio frequency system enabled; acquire () noise radio frequency data () using at least one RF noise detection coil, wherein the noise radio frequency data is acquired simultaneously with the imaging magnetic resonance data; acquire () calibration magnetic resonance data () with radio frequency excitation of the radio frequency system disabled; acquire () reference radio frequency data () using the at least one RF noise detection coil, wherein the reference radio frequency data is acquired simultaneously with the calibration magnetic resonance data; and calculate () a noise calibration () using the reference radio frequency data and the calibration magnetic resonance data.

Magnetic resonance imaging with RF noise detection coils

The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (). It is an object of the invention to enable 'silent' ZTE imaging with sampling of k-space center. According to the invention, the object () is subjected to an imaging sequence of RF pulses () and switched magnetic field gradients (G), wherein an initial RF pulse () is radiated before setting a readout magnetic field gradient (G). An initial MR signal is acquired with the readout magnetic field gradient (G) ramping up after a delay after the initial RF pulse (). Thereafter, the magnetic field gradient (G) remains switched on and the readout direction is gradually varied. Further RF pulses () are radiated in the presence of the readout magnetic field gradient (G) and further MR signal are acquired like in conventional ZTE imaging. Finally, a MR image is reconstructed from the acquired MR signals. Moreover, the invention relates to a MR device and to a computer program for a MR device.

Zero echo time MR imaging with sampling of K-space center

A birdcage resonator () for MR imaging, surrounds an examination volume and includes a plurality of rungs (1-16) arranged in parallel to a longitudinal axis of the examination volume. Each rung (1-16) includes a rung capacitance (C). Two end rings are arranged at the opposite ends of the rungs (1-16), each end ring includes a plurality of ring capacitances (C). Each ring capacitance (C) interconnects a pair of adjacent rungs (1-16). Each pair of adjacent rungs and the interconnecting ring capacitances (C) form a mesh of the birdcage resonator. The ring capacitances (C) and the rung capacitances (C) are proportioned so that: &#x2014;the birdcage resonator () has a plurality of resonant modes that are tuned to the same resonance frequency, and the meshes of the birdcage resonator () are electromagnetically coupled. An MR device () includes the birdcage resonator.

Birdcage body coil for parallel transmit MRI

Coil elements () generate a Bexcitation field in an examination region (), which Bexcitation field is distorted by patient loading (e.g., wavelength effects). Passive shimming elements () are disposed between the coil elements and the subject in order to improve the Bfield uniformity. In one embodiment, passive shimming elements include one or more dielectric rods () disposed below the subject which generate no substantial MR proton signal and which have a permittivity of at least 100 and preferably greater than 500. In another embodiment, tubes () adjacent each coil element are supplied with a dielectric liquid, a thickness of the dielectric liquid between the coil element and the subject adjusting a phase of the Bfield generated by the coil element. Active Bshimming may be combined with passive shimming elements () to effect an improved RF field homogeneity result.

[object Object]

A magnetic resonance method of electric properties tomography imaging of an object includes applying an excitation RF field to the object via a coil at a first spatial coil position (), acquiring resulting magnetic resonance signals via a receiving channel from the object, determining from the acquired magnetic resonance signals a first phase distribution and a first amplitude of a given magnetic field component of the excitation RF field of the coil at the first coil position (), repeating these steps with a coil at a second different spatial coil position (), to obtain a second phase distribution, determining a phase difference between the first and second phase distribution, determining a first and a second complex permittivity of the object, the first complex permittivity comprising the first amplitude of the given magnetic field component and the second complex permittivity comprising the second amplitude of the given magnetic field component and the phase difference, equating the first complex permittivity and the second complex permittivity for receiving a final equation and determining from the final equation a phase of the given magnetic field component for the first coil position ().

Electric properties tomography imaging method and system

The invention relates to a multi-channel (e.g. quadrature) MRI transmit system in which RF power amplifiers having different power capabilities are used in different transmit channels. This results in reduced system costs, due to the avoidance of an unused excess of RF power capability when the power demand for obtaining a homogeneous B1-field (RF shimming) is asymmetric and the asymmetry is qualitatively the same for different imaging applications. The multi-channel transmit unit may also comprise a commutator which enables to selectively connect each RF power amplifier to each drive port of transmit coil arrangement (e.g. a birdcage coil).

Multi-channel transmit MR imaging

The invention relates to a method of MR imaging of at least a portion of a body () of a patient placed in an examination volume of a MR device, the method comprising the steps of:&#x2014;subjecting the portion of the body () to an imaging sequence comprising at least one RF pulse, the RF pulse being transmitted toward the portion of the body () via a RF coil arrangement () to which RF signals are supplied by two or more RF power amplifiers the RF power amplifiers being activated alternately during the imaging sequence in a time-multiplexed fashion, wherein the imaging sequence requires a RF duty cycle and/or a RF pulse duration exceeding the specification of at least one of the RF power amplifiers;&#x2014;acquiring MR signals from the portion of the body (); and&#x2014;reconstructing a MR image from the acquired MR signals. Moreover, the invention relates to a method of MR spectroscopy involving the alternating use of RF power amplifiers in a time-multiplexed fashion.

Magnetic resonance using quazi-continuous RF irradiation

A subject support () of a magnetic resonance (MR) system () includes a table top () supported by a support structure () and configured to move in and out of an examination volume (). The subject support () further includes a coil connector () connected with a local receive coil (). The coil connector () moves between an engaged position in which the coil connector () and the local receive coil () engage and move with the table top () in and out of the examination volume () and a disengaged position in which the coil connector () and the local receive coil () remain stationary out of the examination volume () as the table top () moves in and out of the examination volume ().

MR receive coil platform with selective engagement between receive coil and patient table top

A magnetic resonance sequence includes a repetitively applied radiofrequency pulse capable of causing a specific absorption rate (SAR) hot spot. The composition of the repetitive pulse is varied to generate versions of the repetitive pulse such that the SAR hot spot changes locations with subsequent applications of the repetitive pulse. To generate versions of the pulse, a pilot scan is performed to generate a patient model. A simulation of the SAR response to each of the versions of the repetitive pulse is performed to determine the location of SAR hot spot(s). A plurality of versions of the repetitive pulse is selected to be used in the magnetic resonance sequence.

SAR hotspot reduction by temporal averaging in parallel transmission MRI

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Eindhoven, Netherlands

Paul Royston Harvey