Siemens Aktiengesellschaft

Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Siemens Healthcare Gmbh

Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Siemens Corporation

Isis Innovation Limited

Medical Research Council

University of Glasgow

David Andrew Porter

Stefan Huwer

Thorsten Feiweier

Thorsten Speckner

Radhouene Neji

Robin Heidemann

Tony Hyun Kim

David Grodzki

Jürgen Nistler

Stephan Kannengiesser

Patrick Liebig

Vladimir Jellus

Christian Wünsch

Matthias Guenther

Peter Jezzard

Martin Ott

Saulius Archipovas

Marco Vicari

Christian Schwarzbauer

Robert Frost

Karla Miller

Cristoffer Cordes

Thorsten Honroth

Matthias GÜNTHER

The disclosure is directed to an Echo-Planar-Imaging (EPI) magnetic resonance imaging techniques combined with a variable-density undersampling scheme. The technique comprises generating an RF pulse, applying a switched frequency-encoding read out gradient in a variable time interval, and applying simultaneously an intermittently blipped low-magnitude phase-encoding gradient with a variable value of an integral of the phase-encoding gradient. The aforementioned steps are carried out such that the k-space is at least partially undersampled and the time interval of one read out gradient is varied depending on the integral of the phase encoding gradient, such that a ratio between the variable time interval of the read out gradient and the integral of the corresponding phase encoding gradient is kept above or at a predetermined constant value, which is related to a predetermined criteria of image quality.

Echo-spacing shuffling for echo-planar-imaging

The invention relates to a system for providing at least part of a pulse sequence for acquiring imaging information using a magnetic resonance scanner, a corresponding method and a corresponding computer program. The system comprises a sequence module providing unit, wherein one or more sequence modules comprise a hierarchy description and a parameter description, a sequence hierarchy generating unit for generating a sequence hierarchy based on the sequence modules and the hierarchy description, a parameter dependency graph generating unit for generating a parameter dependency graph based on the parameter dependencies comprised in the parameter description of the sequence modules. The parameter dependencies are decoupled from the sequence hierarchy. The system, method and computer program of the invention allow for an improved determination of at least part of a pulse sequence.

System, method and computer program for magnetic resonance scanners

The invention relates to a system for performing echo-planar spectroscopic imaging. The system comprises an acquisition unit for acquiring magnetic resonance data, wherein the acquisition unit is adapted to use a first encoding gradient in a readout direction and a second encoding gradient in a phase-encoding direction, wherein the first encoding gradient and the second encoding gradient are stepped. The system further comprises a reconstruction unit for reconstructing a magnetic resonance image based on the acquired magnetic resonance data.

System for performing echo-planar spectroscopic imaging

In a method and apparatus for acquiring magnetic resonance image data, improved preparation of nuclear spins is achieved by radiating at least one inversion pulse, which acts site-selectively on at least one inversion pulse range, with the at least one inversion pulse range being situated at least partially outside the area under examination, radiation of at least one excitation pulse, read-out of magnetic resonance signals from the area under examination, and reconstruction of magnetic resonance image data from the read-out magnetic resonance signals, the magnetic resonance image data depicting the area under examination.

Method and apparatus for acquiring magnetic resonance image data

In a method and magnetic resonance (MR) apparatus for acquiring MR signals from an examination object an RF excitation pulse is directed into the examination object while activating magnetic field gradients in two different spatial directions, such that a magnetization in the examination object in the two different spatial directions is limited by the RF excitation pulse and the switching of the magnetic field gradients. The magnetization is excited in one of the two spatial directions, of a slice selection direction, in a number of periodic layers, so MR signals are generated in the multiple periodic slices. The MR signals in the multiple periodic layers are read out using multiple reception coils of the MR scanner.

Imaging method with multi-slice acquisition

In a method and apparatus for magnetic resonance imaging, a particularly quiet magnetic resonance sequence, uses echo-planar imaging with at least one gradient switching in a readout direction, wherein the at least one gradient switching in the readout direction has a slew rate that is less than a maximum slew rate defined by system specification parameters of the magnetic resonance apparatus.

Method and apparatus for EPI magnetic resonance with slew rate controlled and kspace entry optimized

A B1 magnetic field may be regulated during a magnetic resonance tomography (MRT) imaging sequence.

B1 field-based regulation within a sequence for NMR

In a method for acquiring magnetic resonance data with a magnetic resonance system using a magnetic resonance sequence, the sequence has a first partial sequence in which magnetic resonance data are acquired for multiple slices that have to be acquired simultaneously, from which image data for the individual slices are calculated by a reconstruction algorithm. The sequence also has a second partial sequence for determining additional data, which are used to evaluate and/or assess the magnetic resonance data, and which have a spatial resolution that is lower than the magnetic resonance data, in which radio-frequency pulses and readout processes take place in a slice-specific manner through a time offset within a single measuring process, in which a single continuous excitation period with the radio-frequency pulses and a single continuous readout period with the readout processes follow one another, so that separate additional data are directly determined for each slice.

Method and magnetic resonance system for acquiring magnetic resonance data

In a method and apparatus for echo planar magnetic resonance (MR) imaging sequence of phase encoding gradient fields and a sequence of readout gradient fields are applied in order to produce a well-defined zigzag-type trajectory for entering raw data into k-space. Zigzag-type trajectories can be achieved that have flanks without curvature, or without significant curvature. Cartesian methods for image reconstruction of parallel MR imaging are applied to echo planar MR imaging with such zigzag-type trajectories.

Method and magnetic resonance apparatus for echo planar imaging with data entry into k-space along a zigzag trajectory

In a method and magnetic resonance (MR) apparatus for time-dependent intensity correction of diffusion-weighted MR images that are acquired with a sequence of different diffusion gradient fields, different diffusion gradient fields are associated with at least one group, with the association with groups being established so that the diffusion gradient fields that are associated with the same group satisfy an orthogonality criterion. For each group, an MR result image is created from the MR images associated with the group, such that the MR result image has a suppressed direction dependency of the diffusion weighting in comparison to the constituent MR images. An intensity correction can be made based on the multiple MR result images and used to correct the constituent MR images.

Method and magnetic resonance system for time-dependent intensity correction of diffusion-weighted MR images

In a method and system for acquiring magnetic resonance image data from a subject, using a data acquisition unit in which a basic magnetic field is generated, a division is designated in a planar section through the subject that divides the planar section into a first section and a second section, with the homogeneity of the basic magnetic field being better in said first section than in said second section. An echo planar imaging sequence is implemented to acquire the magnetic resonance imaging data, with magnetic resonance data being acquired from the first section only from gradient echo signals in the echo planar imaging sequence, and magnetic resonance data from said the second section being acquired from both gradient echo signals and spin echo signals in the echo planar imaging sequence. The method and apparatus are particularly suited for acquiring functional magnetic resonance imaging (fMRI) data from the brain of a subject, in which the first section is an upper portion of the brain and the second section is a lower portion of the brain.

Magnetic resonance method and apparatus using dual echoes for data acquisition

In a magnetic resonance (MR) method and system for the generation of diffusion information, diffusion-weighted MR images of an examination subject are generated, each image being generated using an individual diffusion gradient. The diffusion gradients, and therefore the MR images, are sorted such that, after the sorting, a predefined number of diffusion gradients respectively forms a group. Each diffusion gradient belongs to at least one of these groups, and the diffusion gradients of the respective same group are all as linearly independent of one another as possible. The MR images whose diffusion gradients form a group are assembled into an MR result image. Spatial transformations between the MR result images are determined, and the MR images are modified using these spatial transformations. The diffusion information is formed with the aid of the modified MR images.

Magnetic resonance system and method to generate diffusion information

In a method described for generating magnetic resonance exposures in which diffusion-coded raw data are acquired with of a diffusion gradient measurement sequence having a number of partial diffusion gradient sequences, at least one diffusion coding gradient pulse is emitted in each partial data set, and raw data of a k-space region are acquired during a first echo after a defined first echo time the k-space regions in total covering a complete k-space. Raw data of an established navigator k-space region are acquired during a second echo after a second echo time the navigator k-space region being identical for different partial diffusion gradient sequences. Reference raw data are acquired by a reference measurement sequence with multiple partial reference sequences.

Method to generate magnetic resonance exposures

In a magnetic resonance apparatus and operating method therefore, 3D navigator data are acquired and are used to correct spatially varying phase errors in contemporaneously acquired imaging data in each shot of a multi-shot data acquisition sequence. A mosaic sampling scheme is used to enter the diffusion-weighted magnetic resonance data and the navigator data into k-space respectively in blocks that each form a subset of the entirety of k-space. The navigator data in each shot are entered into a block that is located at the center of k-space, and, in each shot, the corresponding image data are entered into an offset block in k-space, that is offset in at least one spatial direction from the navigator data block. The offset is varied from shot-to-shot.

Diffusion-weighted magnetic resonance imaging using 3D mosaic segmentation and 3D navigator phase correction

In a method and magnetic resonance (MR) apparatus to acquire spin echo-based MR signals of an examination subject with a multi-spin echo sequence with multiple refocusing pulses after a single excitation pulse in an MR system that has a multichannel RF transmission and reception module: detect a spatial, two-dimensional phase distribution in the examination subject is detected by acquiring navigator signals, a phase and amplitude distribution for the individual transmission channels of the RF transmission and reception module is calculated to generate a magnetic field Bfor one of the RF refocusing pulses to generate the spin echo-based MR signal under consideration of the spatial phase distribution of the navigator signals, and this RF refocusing pulse is radiated via the multichannel RF transmission and reception module with the calculated phase and amplitude distributions of the individual transmission channels.

Growing community of inventors

Poxdorf, Germany

David Andrew Porter