Siemens Healthcare Gmbh

Siemens Healthineers Ag

Centre Hospitalier Universitaire Vaudois

Siemens Aktiengesellschaft

New York University

Stichting Radboud Universiteit

Universitaetsspital Basel

Balgrist Campus Ag

Tom Hilbert

Tobias Kober

Thorsten Feiweier

Gunnar Krueger

Bryan Clifford

Gian Franco Piredda

Peter Speier

Yan Huang

Lars Lauer

Oliver Bieri

Gunnar Krüger

Martijn Cloos

Benedicte Marechal

Josefina Adriana Maria Bastiaansen

Jose Pedro Marques

Patrick Omoumi

Gabriele Bonanno

Daniel Nanz

Mohammad Saeed Rad

Giulia Maria Chiara Rossi

Stefan Sommer

Damien Nguyen

Bénédicte Maréchal

José Pedro Marques

A motion correction method may include: calculating a current motion-corrected MR image based on a current motion parameter of an imaging target and K-space measurement data of the imaging target; calculating current motion-corrected K-space data based on the current motion parameter of the imaging target and the current motion-corrected MR image; calculating a current K-space measurement data error based on the K-space measurement data of the imaging target and the current motion-corrected K-space data; and determining, based on the current K-space measurement data error, whether an iteration end condition is met. If so, using the current motion-corrected MR image as a final motion-corrected MR image to be used. Otherwise, updating the current motion parameter of the imaging target based on the current K-space measurement data error and the current motion-corrected MR image. The method advantageously provides an increased motion correction speed of an MR image.

Motion correction method and apparatus for magnetic resonance image, and magnetic resonance imaging system

An MRI method and system for mapping T1 relaxation times of a biological object with a part having a short-T2 relaxation time. The MRI system first performs one or several magnetization preparation radio frequency pulse sequences, with successive RF pulse sequences being separated by a repetition time interval TR. The MRI system acquires an MRI signal generated by the part of said biological object during each repetition time interval TR in response to a plurality of 3D readout blocks generated by the MRI system and applied to the part of the biological object. For each readout block, an MRI signal is acquired by the MRI system at a different recovery time. Each readout block is sensitive to short-T2 signal. An image of the part is reconstructed from each MRI signal and T1 values are mapped for the part from at least two of said reconstructed images.

Method and system for T1 mapping for tissue characterized by short-T2 relaxation in MRI

A qMRI system and method map qMRI parameters of a biological object. The method includes performing, by the qMRI system, N scans wherein each scan, includes: performing T2-prepared inversion pulse series, each followed by readout blocks, each magnetization preparation RF pulse series is a T2-prepared inversion pulse series containing multiple pulses and an inter-pulse duration, for varying to obtain different T2 weightings; and acquiring, by the MRI system and during each readout block of an MRI, a recovery signal generated by a part of the biological object, wherein for each readout block, an MRI signal is acquired by the MRI system at different inversion times. An image of the part is reconstructed for and from each MRI signal. A voxel-wise signal is created by concatenating intensity values for a same voxel for the reconstructed images. A physical model is fitted to the concatenated intensity values to obtain a qMRI map.

Method and system for simultaneous mapping of quantitative MRI parameters using a T2 prepared inversion

A system and a method for measuring a maturation stage of a biological organ are based on quantitative MR maps for the organ. The method includes acquiring with a first interface and for a subject, a quantitative MR map for the organ. The quantitative MR map includes voxels each characterized by a quantitative value. The quantitative value of each voxel represents a measurement of a physical or physiological property of a tissue of the biological organ for the voxel. The method also includes applying to the quantitative map a trained function to estimate the subject organ maturation stage, and the trained function outputting an age. The method provides with a second interface the maturation stage of the organ of the subject as being the output age.

Method and system for measuring a maturation stage using MRI

A computer-implemented method and system for automated segmentation of anatomical structures of a biological object, include acquiring an MRI image of the object constructed from a set of slices of the object, dividing the set of slices into overlapping groups of consecutive slices, and feeding each overlapping group of consecutive slices as input into a neural network for outputting a labelled map for each inputted slice. For each slice belonging to several overlapping groups, determining for each voxel a final label from specific labels assigned to the voxel by the neural network when considering the labelled maps outputted for the considered slice and assigning to each voxel the final label previously determined for the considered voxel and outputting a final segmentation map of final labels assigned to the voxels of the considered slice. A final 3D segmented image of the object is created from previously obtained final segmentation maps.

Method and system for automated segmentation of biological object parts in MRI

A method for controlling a magnetic resonance imaging system, including: selecting a plurality of spatially non-selective initial RF-pulses each having a predefined pulse shape and a predefined frequency; determining a combined RF-pulse from the initial RF-pulses by choosing a time-offset comprising a relative application time-shift between the initial RF-pulses, wherein this time-offset is chosen such that the initial RF-pulses overlap; and including the combined RF pulse in a pulse sequence applied in a magnetic resonance imaging system.

Method and system for controlling a magnetic resonance imaging system

In a method for improving the contrast of magnetization-transfer-prepared magnetic resonance imaging (MRI), an acquisition scheme comprising a plurality of inversion-recovery (IR)-imaging modules in an interleaved arrangement is selected, a number of magnetization-transfer (MT)-preparation modules is selected, a pulse sequence is generated by arranging at least one MT-preparation module of the number of MT-preparation modules between two successive IR-preparation modules of the interleaved IR-imaging modules or in front of the first IR-preparation module of a group of interleaved IR-imaging modules, and the pulse sequence for an MRI examination is applied or saved. Each IR-imaging module may include an IR-preparation module and a slice acquisition module.

Method and system for improving the contrast of magnetization-transfer-prepared MRI

A system and a method determine a value for a parameter. Reference values for the parameter are determined from a group of objects. A first technique is used by the system for determining for each object the reference value from a first set of data. A learning dataset is created by associating for each object of the group of objects a second set of data and the reference value. The second set of data is acquired by the system according to a second technique for determining values of the parameter and is configured for enabling a determination of the parameter. A machine learning technique trained on the learning dataset is used for determining a value of the parameter. The second set of data obtained for each of the objects is used as input in a machine learning algorithm and its associated reference value is used as output target.

Quantitative mapping by data-driven signal-model learning

A method and a system create an age-specific quantitative atlas for a biological object. The method includes obtaining a quantitative map of the biological object for each subject of a healthy subject population, generating an age-specific initial map for the biological object using a weighted mean, and spatially registering each of the quantitative maps on the age-specific initial map. The generating and registering steps are repeated iteratively until reaching a first predefined alignment threshold between all spatially registered quantitative maps. The new age-specific initial map obtained is stored at the end of the iterative process of the repeating step as the age-specific quantitative atlas for a biological object characterized by the specific age.

Age-specific image atlas

A tissue type fraction within a biological object is determined by a phase-cycled acquisition of several images of the object and deriving a complex signal profile for each voxel of the acquired images; generating a multidimensional dictionary of simulated signal profiles, wherein each simulated signal profile is configured for simulating the previously derived complex signal profile; using a weight optimization algorithm configured for expressing the complex signal profile as a weighted sum of the simulated signal profiles, wherein the weight optimization algorithm provides as output for each voxel a matrix M of optimized weights; for each voxel and each dimension of the obtained matrix M, extracting from the matrix M a distribution of the obtained optimized weights; and determining a type of tissue composing each voxel from the obtained distributions.

Method and system for mapping a fraction of tissue concentrations in MRI

A system and method generate a synthetic image with switchable image contrast components for a biological object. The method includes: a) using first and second quantitative MRI acquisition techniques for measuring a value of first or second quantitative parameters Q, Qfor the biological object and generating first and second quantitative maps, the first and second quantitative MRI acquisition techniques generate first and second contrast-weighted images; b) using the first and second quantitative maps, and the first and second contrast weighted images as inputs in a model configured for generating a synthetic image M with arbitrary sequence parameters P, P, P, according to:()|wherein Cwith i=1, 2, are contrast components for the generation of the synthetic image M coming from respectively the first (i=1) and second (i=2) contrast-weighted images (i=1) and f is a function of Q, Q, P, Pand P; and c) displaying the synthetic image M.

Method and system for generating synthetic images with switchable image contrasts

The disclosure includes a method for generating quantitative magnetic resonance (MR) images of an object under investigation. A first MR data set of the object under investigation is captured in an undersampled raw data space, wherein the object under investigation is captured in a plurality of 2D slices, in which the resolution in a slice plane of the slices is in each case higher than perpendicular to the slice plane, wherein the plurality of 2D slices are in each case shifted relative to one another by a distance which is smaller than the resolution perpendicular to the slice plane. Further MR raw data points of the first MR data set are reconstructed with the assistance of a model using a cost function which is minimized. The cost function takes account of the shift of the plurality of 2D slices perpendicular to the slice plane.

Iterative reconstruction of quantitative magnetic resonance images

In a magnetic resonance (MR) apparatus, and model-based method, for identifying a nuclear spin-dependent attribute of a subject, MR signals are acquired in multiple repetitions of an MR data acquisition sequence that is changed from repetition-to-repetition so as to deliberately encode effects of magnetization transfer between nuclear spins into the acquired MR signals. A model is generated, composed of at least two molecule pools, in which a single magnetization transfer parameter is used that is derived from the MR signals in which the magnetization transfer is encoded. A nuclear spin-dependent attribute of the subject is then identified, by comparing at least one MR signal evolution from the subject to at least one signal evolution produced by the model.

Method and apparatus for mitigating the effect of magnetization transfer in model-based magnetic resonance techniques

Organ tissue properties of a patient are automatically compared with organ tissue properties of a healthy subject group. A population norm for the organ tissue properties is determined by: selecting at least two different tissue properties of the organ; determining for each tissue property previously selected and for each subject of said group a quantitative tissue property map; for each subject of the group, calculating a joint histogram from all the quantitative tissue property maps obtained for said subject; and determining an averaged joint histogram from all subjects of the healthy group, thus defining the population norm. A comparison is automatically performed of the averaged joint histogram with a patient joint histogram obtained for the organ tissue properties of the patient, by calculating a statistical deviation of values of a patient joint histogram relative to values of the averaged joint histogram, and mapping the statistical deviation to the patient organ.

Method and system for abnormal tissue detection using z-scores in a joint histogram

A method is disclosed for recording a parameter map of a target region via a magnetic resonance device. In at least one embodiment, an optimization method is used for the iterative reconstruction of the parameter map. In the optimization method, the deviation of undersampled magnetic resonance data of the target region present in the k-space for different echo times, magnetic resonance data of a portion of the k-space being present in each case for each echo time, is assessed from hypothesis data of a current hypothesis for the parameter map obtained as a function of the parameter from a model for the magnetization. To determine the magnetic resonance data of a portion of the k-space, undersampled raw data is initially acquired within the portions by way of the magnetic resonance device embodied for parallel imaging, and missing magnetic resonance data within the portions is completed by way of interpolation.

Growing community of inventors

Lausanne, Switzerland

Tom Hilbert