Koninklijke Philips Corporation N.v.

University of Washington

U.S. Philips Corporation

University of Texas System

Peter Boernert

Kay Nehrke

Ulrich Wolfgang Katscher

Mariya Ivanova Doneva

Ingmar Graesslin

Thomas Erik Amthor

Tim Nielsen

Holger Eggers

Jochen Keupp

Peter Koken

Johannes Adrianus Overweg

Karsten Sommer

Jinnan Wang

Peter Vernickel

Christian Stehning

Chun Yuan

Bernd E Aldefeld

Bernhard Gleich

Miha Fuderer

Johan Samuel Van Den Brink

Paul Royston Harvey

Sascha Krueger

Julien Senegas

Falk Uhlemann

Arne Ewald

Michael Gunter Helle

Rudolf Mathias Johannes Nicolaas Lamerichs

Michel Paul Jurriaan Jurrissen

Jurgen Edwin Rahmer

Ferdinand Schweser

Christoph G Leussler

Steffen Weiss

Michael Harald Kuhn

Peter Forthmann

Steffen Renisch

Hanno Heyke Homann

Fabian Wenzel

Ingo Schmale

Klaas P Pruessmann

Jan Jakob Meineke

Johan Michiel Den Harder

Tobias Ratko Voigt

Radu Serban Jasinschi

William Sean Kerwin

Jurgen Erwin Rahmer

Dirk Manke

Adrianus Joseph Willibrordus Duijndam

Thomas Hendrik Rozijn

Michael Günter Helle

Michael C Steckner

Wilhelmus Reinerius Maria Mens

Huijun Chen

Arjan Willem Simonetti

Sven Biederer

Nick Flaeschner

Bertram Wilm

Ivan Dimitrov

Wim Crooijmans

Gwenael Henri Herigault

George Randall Duensing

Nadine Gdaniec

Ivan Pedrosa

Christophe Michael Jean Schulke

Juergen Rahmer

Kim Cornelia Carolina Van De Ven

Christophe Michael Jean Schuelke

Nick Flaschner

Mariya Ivanova Donevea

Susanne Heinzer

Miha Federer

Tobias Richard Schaeffter

The invention relates to a method of MR imaging. It is an object of the invention to provide an improved Bmapping method that is less affected by Trelaxation. The invention proposes that a first stimulated echo imaging sequence () is generated comprising at least two preparation RF pulses (α) radiated during a first preparation period () and a sequence of reading RF pulses (β) radiated during a first acquisition period () temporally subsequent to the first preparation period (). A first set of FID signals (I) and a first set of stimulated echo signals (I) are acquired during the first acquisition period (). A second stimulated echo imaging sequence () is generated comprising again at least two preparation RF pulses (α) radiated during a second preparation period () and a sequence of reading RF pulses (β) radiated during a second acquisition period () temporally subsequent to the second preparation period (). A second set of FID signals (I) and a second set of stimulated echo signals (I) are acquired during the second acquisition period (). The first and second sets of FID signals (IFID) have different T-weightings and/or the first and second sets of stimulated echo signals (I) have different T-weightings. A Bmap indicating the spatial distribution of the RF field of the RF pulses is derived from the acquired first and second sets of FID (I) and stimulated echo (I) signals, wherein the different T-weightings are made use of to compensate for influences on the Bmap caused by Trelaxation. Preferably, either the first or the second preparation period () is preceded by an RF inversion pulse to obtain the different T-weightings. Moreover, the invention relates to an MR device () and to a computer program for an MR device ().

MR imaging with T1 compensated B1 mapping

The invention relates to a method of Dixon-type MR imaging. The object () is subjected to at least two shots of an imaging sequence, each shot comprising an excitation RF pulse followed by a series of refocusing RF pulses, wherein at least a pair of phase encoded echoes, a first echo at a first echo time and a second echo at a second echo time, is generated in each time interval between two consecutive refocusing RF pulses. Two sets of echo signal pairs, a first set and a second set, are acquired using bipolar pairs of readout magnetic gradients in two respective shots of the imaging sequence. The bipolar pair of readout magnetic field gradients in the acquisition of the second set has an opposite polarity to that of the bipolar pair of readout magnetic field gradients in the acquisition of the first set. Alternatively or additionally the temporal course of the readout magnetic field gradients in the acquisition of the second set is reversed with respect to the temporal course of the readout magnetic field gradients in the acquisition of the first set. Alternatively or additionally the acquisitions of the first and second sets are different from each other with respect to the gradient areas of magnetic field gradients in the readout direction (M) preceding respectively succeeding the bipolar pair of readout magnetic field gradients. Finally, an MR image is reconstructed from the acquired first and second sets of echo signal pairs, whereby signal contributions from water protons and fat protons are separated. Moreover the invention relates to an MR device () and to a computer program to be run on an MR device ().

Dixon-type water/fat separation MR imaging

The present disclosure relates to a medical imaging method, comprising: receiving () a set of subject parameters descriptive of a subject; in response to inputting () the set of subject parameters into a trained deep neural network, DNN, receiving () from the trained DNN a predicted task; presenting the task to the subject; controlling () an MRI system () for acquiring fMRI data from the subject in response to the predicted task performed by the subject during the acquisition.

fMRI task settings with machine learning

Disclosed herein is a medical system () comprising a memory () storing machine executable instructions () and an image generating neural network (). The image generating neural network is configured for outputting synthetic magnetic resonance image data () in response to receiving reference magnetic resonance image data () as input. The synthetic magnetic resonance image data is a simulation of magnetic resonance image data acquired according to a first configuration of a magnetic resonance imaging system when the reference magnetic resonance image data is acquired according to a second configuration of the magnetic resonance imaging system. Execution of the machine executable instructions causes a computational system () to: receive () measured k-space data () acquired according to the first configuration of the magnetic resonance imaging system; receive () the reference magnetic resonance image data; receive () the synthetic magnetic resonance image data by inputting the reference magnetic resonance image data into the image generating neural network; and reconstruct () corrected magnetic resonance image data () from the measured k-space data and the synthetic magnetic resonance image data.

Correction of magnetic resonance images using multiple magnetic resonance imaging system configurations

The invention provides for a medical imaging system () comprising a memory () storing machine executable instructions () and a configured artificial neural network (). The medical imaging system further comprises a processor () configured for controlling the medical imaging system. Execution of the machine executable instructions causes the processor to receive () magnetic resonance imaging data (), wherein the magnetic resonance imaging data is BOLD functional magnetic resonance imaging data descriptive of a time dependent BOLD signal () for each of a set of voxels. Execution of the machine executable instructions further causes the processor to construct () a set of initial signals () by reconstructing the time dependent BOLD signal for each of the set of voxels using the magnetic resonance imaging data. Execution of the machine executable instructions further causes the processor to receive () a set of modified signals () in response to inputting the set of initial signals into the configured artificial neural network. The configured artificial neural network is configured for removing physiological artifacts from the set of initial signals.

Functional magnetic resonance imaging artifact removal by means of an artificial neural network

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 silent ZTE imaging with self-refocusing. The method of the invention comprises the steps of:—specification of a set of radial k-space spokes to cover a spherical k-space volume;—selection of subsets of a predetermined number of spokes from the specified set so that the concatenation of the spokes contained in each of the subsets forms a closed trajectory in k-space, wherein the selection of the subsets involves optimizing a cost function;—subjecting the object () to a zero echo time imaging sequence, wherein each of the subsets of spokes is acquired as a sequence of gradient echo signals; and—reconstructing an MR image from the acquired spokes. Moreover, the invention relates to a MR device and to a computer program for a MR device.

Efficient self-refocusing zero echo time MR imaging

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 and high-quality non-Cartesian MR imaging, even in situations of strong Binhomogeneity. In accordance with the invention, the method comprises: —subjecting the object to an imaging sequence comprising at least one RF excitation pulse and modulated magnetic field gradients, —acquiring MR signals along at least one non-Cartesian k-space trajectory, —reconstructing an MR image from the acquired MR signals, and —detecting one or more mal-sampling artefacts caused by Binhomogeneity induced insufficient k-space sampling in the MR image using a deep learning network. Moreover, the invention relates to a MR device () and to a computer program.

Spiral MR imaging with off-resonance artefact correction

A method of operating a magnetic resonance imaging system () with regard to acquiring multiple-phase dynamic contrast-enhanced magnetic resonance images, the method comprising steps of acquiring () a first set of magnetic resonance image data (x) prior to administering a contrast agent to the subject of interest (), by employing a water/fat magnetic resonance signal separation technique, determining () a first image of the spatial distribution of fat (I) of at least the portion of the subject of interest (), acquiring () at least a second set of magnetic resonance image data (x) of at least the portion of the subject of interest () after administering the contrast agent to the subject of interest (), by employing a water/fat magnetic resonance signal separation technique, determining () at least a second image of the spatial distribution of fat (I) of at least the portion of the subject of interest (), applying () an image registration method to the second image of the spatial distribution of fat (I) with reference to the first image of the spatial distribution of fat (I) for correcting a potential motion of the subject of interest (); and a magnetic resonance imaging system () having a control unit () that is configured to carry out steps (-) of such a method; and a software module () for carrying out such a method, wherein the method steps (-) to be conducted are converted into a program code that is implementable in a memory unit () and is executable by a processor unit () of the magnetic resonance imaging system ().

Method of improved multiple-phase dynamic contrast-enhanced magnetic resonance imaging with motion correction using water/fat signal separation

The invention provides for a method of operating a magnetic resonance imaging system for imaging a subject. The method comprises acquiring () tagged magnetic resonance data () and a first portion () of fingerprinting magnetic resonance data by controlling the magnetic resonance imaging system with tagging pulse sequence commands (). The tagging pulse sequence commands comprise a tagging inversion pulse portion () for spin labeling a tagging location within the subject. The tagging pulse sequence commands comprise a background suppression portion (). The background suppression portion comprises MRF pulse sequence commands for acquiring fingerprinting magnetic resonance data according to a magnetic resonance fingerprinting protocol. The tagging pulse sequence commands comprise an image acquisition portion (). The method comprises acquiring () control magnetic resonance data () and a second portion () of the fingerprinting magnetic resonance data by controlling the magnetic resonance imaging system with control pulse sequence commands. The control pulse sequence commands comprise a control inversion pulse portion (). The control pulse sequence commands comprise the background suppression portion ('). The control pulse sequence commands comprise the image acquisition portion (). The method comprises reconstructing () tagged magnitude images () using the tagged magnetic resonance data. The method comprises reconstructing () a control magnitude images () using the control magnetic resonance data. The method comprises constructing () an ASL image by subtracting the control magnitude images and the tagged magnitude images from each other. The method comprises reconstructing () a series of magnetic resonance fingerprinting images () using the first portion of the fingerprinting magnetic resonance data and/or the second portion of the fingerprinting magnetic resonance data. The method comprises generating () at least one magnetic resonance parametric map () by comparing the series of magnetic resonance fingerprinting images with a magnetic resonance fingerprinting dictionary.

Combined arterial spin labeling and magnetic resonance fingerprinting

The invention provides for a magnetic resonance imaging system () for acquiring MRF magnetic resonance data () from a subject () within a region of interest (). The magnetic resonance imaging system comprises a processor () for controlling the magnetic resonance imaging system and a memory () for storing machine executable instructions () and MRF pulse sequence commands (). The MRF pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the MRF magnetic resonance data according to a magnetic resonance fingerprinting protocol. Execution of the machine executable instructions causes the processor to: acquire () the MRF magnetic resonance data for the region of interest by controlling the magnetic resonance imaging system with the MRF pulse sequence commands; receive () at least one magnetic resonance image () descriptive of the region of interest; identify () anatomical regions () within the region of interest using an anatomical model (); select () a local magnetic resonance fingerprinting dictionary () from a set of magnetic resonance fingerprinting dictionaries for each of the anatomical regions, wherein the local magnetic resonance fingerprinting dictionary comprises a listing of calculated MRF signals for a set of predetermined substances specific to each of the anatomical regions; and calculate () a composition mapping () of the predetermined substances for each of the anatomical regions using the MRF magnetic resonance data and the local magnetic resonance fingerprinting dictionary, wherein the composition mapping is a spatial average within each of the anatomical regions.

Selection of magnetic resonance fingerprinting dictionaries for anatomical regions

A medical instrument includes a magnetic resonance (MR) imaging system with an imaging zone and a gradient coil system with three orthogonal gradient coils. A processor controls the medical instrument to: repeatedly control the MR imaging system with calibration pulse sequence commands to acquire the MR calibration data for multiples slices using at least one of the three orthogonal gradient coils to generate the slice select gradient magnetic field; compute a Fourier transform of the MR calibration data for each of the voxels of the multiple slices in the phase encoding directions; compute an expansion of the Fourier transformed MR calibration data into spherical harmonics; and calculate a three-dimensional gradient impulse response function for the at least one of the three orthogonal gradient coils using the expansion into spherical harmonics. The calibration pulse sequence commands are configured to acquire MR calibration data from a phantom according to a calibration protocol with two-dimensional phase encoding perpendicular to a slice select gradient magnetic field.

Determination of higher order terms of the three-dimensional gradient impulse response function

The invention relates to a method of MR imaging of at least a portion of a body () placed in a main magnetic field within the examination volume of a MR device (). It is an object of the invention to facilitate the planning of an arterial spin labeling (ASL) MR imaging session and to improve the image quality in perfusion weighted MR imaging. The method of the invention comprises the following steps: acquiring angiographic MR signal data by subjecting the portion of the examined body () to one or more MR angiography scans; deriving quantitative blood flow parameters from the angiographic MR signal data; &#x2014;computing a labeling efficiency of an ASL sequence from the sequence parameters of the ASL sequence and from the quantitative blood flow parameters; optimizing the sequence parameters by maximizing the labeling efficiency; acquiring perfusion weighted MR signal data by subjecting the portion of the body to the ASL sequence; and&#x2014;reconstructing a MR image from the perfusion weighted MR signal data. Moreover, the invention relates to a MR device () and to a computer program for a MR device ().

Planning support for selective arterial spin labeling MR imaging methods

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

A method of employing a central computer database () for supporting a characterization of tissue by magnetic resonance fingerprinting measurements, includes: exciting nuclei of a subject of interest by applying () a radio frequency excitation field Bgenerated according to a magnetic resonance fingerprinting sequence (), acquiring () magnetic resonance imaging signal data from radiation emitted by excited nuclei of the subject of interest, transferring () a magnetic resonance fingerprinting data set () to the central computer database (), retrieving () a predefined dictionary from the central computer database (), matching () the acquired magnetic resonance imaging signal data to the retrieved dictionary by applying a pattern recognition algorithm to determine a value () or a set of values () for at least one physical quantity (T, T), adding () at least the determined value () or the determined set of values () as a new entry of an associated medical data set () to the central computer database (), and making () the new entry of an associated medical data set () accessible to users of the central computer database (). A magnetic resonance fingerprinting data collection and analysis system () includes a central computer database, a data receiving unit (), a data output unit () and a data analysis device () configured to carry out the method.

Magnetic resonance fingerprinting data collection and analysis system

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

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Hamburg, Germany

Peter Boernert