Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Koninklijke Phillips Electronics N.v.

Koninklijke

Koninklijke Philips Electronics N.v.

Philips Intellectual Property & Standards Gmbh

Miha Fuderer

Johan Samuel Van Den Brink

Paul Royston Harvey

Michel Paul Jurriaan Jurrissen

Ulrich Wolfgang Katscher

Elwin De Weerdt

Johannes J Cuppen

Zhaolin Chen

Peter Boernert

Kay Nehrke

Filips Van Liere

Zhiyong Zhai

Johannes Petrus Groen

Adrianus Joseph Willibrordus Duijndam

Thomas Hendrik Rozijn

Johannes Martinus Peeters

Silke Hey

Patrick Gross

Johannes Matia Van Eggermond

Dirk Jan Broer

Christoph G Leussler

Michael Andrew Morich

Ralph Kurt

Marc Paul Saes

Thomas Erik Amthor

Cornelis Leonardus Gerardus Ham

Peter Forthmann

Johannes J Van Vaals

Emiel Peeters

Mariya Ivanova Doneva

Feng Huang

Roel Penterman

Dietmar W Kunz

Christian Stehning

Gabriele Marianne Beck

Klaas P Pruessmann

Johannes H Den Boef

Gerardus Bernardus Jozef Mulder

Philippe Abel Menteur

Robert Paul Kleihorst

Michel Paul Barbara Van Bruggen

Gerrit H Van Yperen

Wei Lin

Willem Marten Prins

Til Aach

Jeroen Alphons Pikkemaat

Cornelis L G Ham

Jean-Pierre Franciscus Alexander Maria Ermes

Bertram Wilm

Hans Van Zon

Ivan Dimitrov

Gerrit Hendrik Van Yperen

Arianne Margarethe Corinne Van Muiswinkel

Gwenael Henri Herigault

Elizabeth Anne Moore

Michael Jozef Duijvestijn

Jurgen Edwin Rahmer

Marinus Ludovicus Adrianus Vrinten

Franciscus Johannes Maria Benschop

Dirk Van Ormondt

Jacob A Den Boer

Karsten Ottenberg

Antoon F Mehlkope

Teunis R Van Heels-Bergen

Thomas L Hoogenboom

Jan F De Becker

Kim Van De Ven

Jacques Den Boer

Franciscus J M Benschop

Bin Xie

Arthur Felipe Nisti Grigoletto Borgonovi

Joost M De Haan

Jürgen Erwin Rahmer

Christoph Leussler

Klaas Pruessmann

Michel PJ Jurrissen

Mariya I Doneva

Michel P J Jurrissen

Adrianus J W Duijndam

Willem M Prins

Paul R Harvey

Ulrich Katscher

Arianne M C Van Muiswinkel

The invention relates to a method of MR imaging of an object () positioned in an examination volume of an MR device (). It is an object of the invention to enable spiral MR imaging with a reduced level of ringing artefacts close to strong local IC main magnetic field inhomogeneity. The method of the invention comprises the following steps:—generating a spin echo by subjecting the object () to an imaging sequence comprising an RF excitation pulse () followed by an RF refocusing pulse (), wherein a modulated readout magnetic field gradient () is applied subsequent to the RF refocusing pulse (),—acquiring MR signal data by recording the spin echo along a spiral trajectory in k-space, wherein the waveform of the readout magnetic field gradient () defining the spiral trajectory starts before the spin echo center (), and—reconstructing an MR image from the acquired MR signal data. Moreover, the invention relates to an MR device () and to a computer program for an MR device ().

Spin echo MR imaging with spiral acquisition

A magnetic resonance examination method comprises acquisition of a set of magnetic resonance signals from magnetic spins in an object by way of a receiver antenna, the magnetic resonance signals' signal levels are related to an independent reference level that is independent of the receiver antenna's sensitivity to form a calibrated signal level of the magnetic resonance signals, the calibrated signal levels are recorded in terms of a relative density of ordered transverse spins (DOTS). The independent reference level may be derived from the signal-to-thermal-noise ratio. The calibrated signal level in terms of DOTS in μM/T reflects predominantly a tissue property (of (a voxel of) the patient to be examined) as well as details or characteristics of the acquisition sequence used.

Magnetic resonance examination method

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 efficient spiral MR imaging even in situations of strong Bo inhomogeneity. The method of the invention comprises: subjecting the object () to an imaging sequence comprising at least one RF excitation pulse and sinusoidally modulated magnetic field gradients, acquiring MR signals along two or more spiral k-space trajectories () as determined by the sinusoidal modulation of the magnetic field gradients, wherein the origins of the spiral k-space trajectories are offset from each other, and reconstructing an MR image from the acquired MR signals. Moreover, the invention relates to a MR device () and to a computer program for a MR device ().

MR imaging with spiral acquisition

Disclosed herein is a medical system () comprising: a memory () storing machine executable instructions () and a processor (). Execution of the machine executable instructions causes the processor to: receive () magnetic resonance imaging data (), wherein the magnetic resonance imaging data has a spiral k-space sampling pattern; reconstruct () at least one preliminary magnetic resonance image () from the magnetic resonance imaging data; construct () a first set of equations comprising () each of the at least one preliminary magnetic resonance image being equal to an image transformation of at least one clinical image, wherein the image transformation makes use of a first spatially dependent kernel for each of the at least one clinical image (″); construct () a second set of equations () comprising at least one regularization matrix (″) times the at least one clinical image; and numerically () solve the first set of equations and the second set of equations simultaneously for the at least one clinical image.

Reconstruction of spiral k-space sampled magnetic resonance images

A method of magnetic resonance (MR) imaging includes a phantom that is inexpensive to produce and enables simple, practical and fast assessment of image sharpness, in particular for checking image quality of MR imaging with spiral acquisition. The method includes subjecting a phantom, which comprises a volume filled with a bulk of granules of solid material surrounded by a liquid, to an imaging sequence, acquiring MR signals from the phantom, reconstructing an MR image from the acquired MR signals, and deriving a measure of the local image sharpness in two or more different image regions from the MR image, wherein each image region is a representation of a part of the phantom volume.

Image quality assessment of magnetic resonance images using a phantom

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 fast spiral MR imaging with a defined T2 contrast. The method of the invention comprises the following steps: &#x2014;generating a number of spin echoes by subjecting the object () to one or 5 more shots of an imaging sequence, each shot comprising an RF excitation pulse () followed by a number of RF refocusing pulses (), wherein modulated readout magnetic field gradients () are applied in each interval between successive RF refocusing pulses (), &#x2014;acquiring MR signal data, wherein each spin echo is recorded along a spiral trajectory (--) in k-space which winds around the k-space origin with varying radial distance, wherein the trajectory () of at least one spin echo has a different rate of variation of the radial distance at least in a central k-space region compared to the trajectories () of the other spin echoes, and&#x2014;reconstructing an MR image from the acquired MR signal data. Moreover, the invention relates to an MR device () and to a computer program for an MR device ().

Multi-echo MR imaging with spiral acquisition

A B-mapping method determines the spatial distribution of a static magnetic field in a pre-selected imaging zone comprising computation of the spatial distribution of a static magnetic field from a spatial distribution of spin-phase accruals between magnetic resonance echo signals from the imaging zone and an estimate of the proton density distribution in the imaging zone. The invention provides the field estimate also in cavities and outside tissue. Also the field estimate of the invention suffers less from so-called phase-wraps.

MRI method for B-mapping

The present invention provides a radio frequency (RF) receive coil device for use in a magnetic resonance (MR) imaging system, comprising a RF receive coil, a plug for connecting the RF receive coil to the MR imaging system, sensing means for sensing the presence of a magnetic field of the MR imaging system, detecting means for detecting if the plug is connected to the MR imaging system, and a warning means for generating a warning when the sensing means sense the presence of a magnetic field of the MR imaging system and the detecting means detect that the plug is not connected to the MR imaging system.

Radio frequency receive coil for use in magnetic resonance imaging systems with disconnection warning

A cryogenic cooling system () comprising a cryostat (), a two-stage cryogenic cold head () and at least one thermal connection member () that is configured to provide at least a portion of a heat transfer path () from the second stage member () to the first stage member () of the two-stage cryogenic cold head (). The heat transfer path () is arranged outside the cold head (). A thermal resistance of the provided at least portion of the heat transfer path () at the second cryogenic temperature is larger than a thermal resistance of the provided at least portion of the heat transfer path () at the first cryogenic temperature.

Cryogenic cooling system with temperature-dependent thermal shunt

A method of MR imaging of a body () of a patient reduces contrast blurring in PROPELLER imaging combined with multi-echo acquisitions. The method includes the steps of:

Propeller MR imaging with relaxation weightings varying between k-space blades and k-space data lines

A magnetic resonance imaging system () includes a radio-frequency system () with multiple coil elements () for acquiring magnetic resonance data () and a memory () for storing machine executable instructions () and pulse sequence commands (). The pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data according to a SENSE imaging protocol. Execution of the machine executable instructions causes a processor () to: control () the magnetic resonance imaging system to acquire the magnetic resonance data using the pulse sequence commands; reconstruct () a set of folded magnetic resonance images () from the magnetic resonance data; calculate () a voxel deformation map () from a magnetic field inhomogeneity map; and calculate () a set of unfolding matrices () using a least partially a coil sensitivity matrix () for the multiple coil elements, wherein the set of unfolding matrices includes at least one modified unfolding matrix which is calculated at least partially using the a coil sensitivity matrix and the voxel deformation map. Undistorted magnetic resonance image data () is calculated () using the set of folded magnetic resonance images and the set of unfolding matrices.

BO-corrected sensitivity encoding magnetic resonance imaging

A magnetic resonance imaging system includes a gradient system and a processor for controlling the magnetic resonance imaging system. Execution of machine executable instructions causes the magnetic resonance imaging system to: acquire by coil elements first magnetic resonance data simultaneously from a group of passive local probes, wherein the first group of passive local probes includes a plurality of passive local probes located spaced apart from each other; disentangle contributions to the first magnetic resonance data from the individual local probes, calculate for the magnetic resonance imaging system a gradient impulse response function of the gradient system using the first magnetic resonance data from the local probes; and determine correction factors using the gradient impulse response function

Gradient impulse response function mapping

The invention provides for a magnetic resonance imaging system () comprising: a radio-frequency system ('&#x2033;) for acquiring magnetic resonance data () from an imaging zone (), wherein the radio-frequency system comprises multiple antenna elements (&#x2032;&#x2033;); a memory () containing machine executable instructions () and pulse sequence commands (), wherein the pulse sequence commands cause the processor to acquire magnetic resonance data from the multiple antenna elements according to a SENSE protocol; and a processor. Execution of the machine executable instructions causes the processor to: control () the magnetic resonance imaging system with the pulse sequence commands to acquire the magnetic resonance data; reconstruct () a preliminary image () using the magnetic resonance imaging data; calculate () a fit () between an anatomical model () and the preliminary image, wherein the anatomical model comprises a motion likelihood map (); identify () at least one image artifact origin () at least partially using the motion likelihood map and the fit; determine () an extended SENSE equation () at least partially using at least one image artifact origin; and construct () a corrected SENSE image () using the extended SENSE equation.

Removal of image artifacts in sense-MRI

A magnetic resonance examination system is disclosed comprising a field probe system to measure the magnetic field distribution of the main magnetic field and gradient magnetic field. The measurements are made in an earlier configuration and yield the resultant magnetic field due to gradient switching or external causes. From the measured resultant magnetic field the response relation is derived and stored in the memory. The response relation from the memory is available for compensating activation of the gradient fields or correction in reconstruction for the response relation in reconstruction. This compensation or correction can be carried-out in a current configuration. Thus is the current configuration to field probes are needed.

Magnetic resonance examination system with field probes

The present invention relates to a method for side-band suppression in a Magnetic Resonance imaging, MRI, system (), the method comprising providing a first multiband RF pulse for simultaneously exciting at least two slices in a subject () at a first and a second frequency band () and to acquire using the MRI system () signals () from the excited two slices and at least one additional signal () at a third frequency band (), the additional signal () resulting from a sideband excitation of a slice different from the two slices; using the first multiband RF pulse for determining the additional signal (); deriving a pre-compensating term from the first multiband RF pulse and the additional signal (), adding the pre-compensating term to the first multiband RF pulse to obtain a second multiband RF pulse, thereby replacing the first multiband RF pulse by the second multiband RF pulse for suppressing at least part of the additional signal ().

Method of generating multi-band RF pulses

Growing community of inventors

Eindhoven, Netherlands

Miha Fuderer