Siemens Healthcare Gmbh

Siemens Healthineers Ag

Gregor Koerzdoerfer

Mathias Nittka

Peter Speier

Jianing Pang

David Grodzki

Thorsten Feiweier

Josef Pfeuffer

Thomas Kluge

Techniques are disclosed for acquiring data of an examination object in at least two slices by means of a pulse sequence. Time intervals between excitations of neighboring slices and associated minimum intervals are determined. From these, time intervals to be adapted between excitations of neighboring slices are determined and adapted before a measurement protocol is executed, with the adapted time intervals. Through the determination of a minimum time interval between excitations of neighboring slices and the adaptation of the time intervals between excitations of neighboring slices, a falsification of measurement results can be avoided, measurement time of the chosen measurement protocol is not increased, and the user is not restricted in their choice of the slices to be excited.

Acquisition of data of an examination object by means of magnetic resonance with improved time management

In a method for generating an image data set and a reference image data set: a first raw data set is provided that is acquired with a MR system and that includes measurement signals at read-out points in k-space that lie on a first k-space trajectory; a second raw data set is provided that is acquired with the same MR system and at the same examination object at read-out points that lie on a second, different k-space trajectory that is different from the first k-space trajectory; image data sets are reconstructed from the first raw data set; a reference image data set is reconstructed from the second raw data set; the reference image data set is compared with each image dataset to generate respective similarity values; and an image data set is selected having a greatest similarity value.

Method for generating at least one image data set and one reference image data set, data carrier, computer program product and magnetic resonance system

In a method for generating an image dataset and one reference image dataset: a first raw dataset is provided that is recorded using a MR system, the first raw dataset including measurement signals at readout points in k-space that lie on a first k-space trajectory; a second raw dataset is provided that is recorded using the same MR system and on the same examination object, the second raw dataset including measurement signals at readout points in k-space that lie on a second, different k-space trajectory; image datasets are reconstructed from the first raw dataset, where a separate equalization coefficient set is used before the reconstruction of each image dataset; a reference image dataset is reconstructed from the second raw dataset; the reference image data set is compared with each image dataset to generate respective similarity values; and the image dataset is selected with a greatest similarity value.

Method for generating at least one image dataset and one reference image dataset, data carrier, computer program product, and magnetic resonance system

In a method and apparatus for determining parameter values in voxels of an examination object using magnetic resonance fingerprinting (MRF), a first signal comparison is made of signal characteristics of established voxel time series with first comparison signal characteristics. Further synthetic comparison signal characteristics are generated from the first comparison signal characteristics and values determined in the first signal comparison. The generated further comparison signal characteristics are used to perform a further signal comparison, with which values of at least a first and a second further parameter are determined. From the further comparison signal characteristics, a value of at least one further parameter is determined that could not necessarily already be determined in the first signal comparison.

Magnetic resonance fingerprinting method and apparatus

In a Method and a device for magnetic resonance imaging of a subject using a spoiled gradient echo sequence, a Bmagnetic field strength of at most 1.5 T is used during the sequence. As part of the sequence a slice select gradient acting as a spoil gradient is played out. Substantially simultaneously with the slice select gradient a predetermined RF pulse is played out in the sequence, wherein a time-bandwidth product of the RF pulse is set so that a majority of the energy of the RF pulse is transmitted in its central main lobe.

Method and device for magnetic resonance imaging, and corresponding computer program product

The disclosure facilitates determining patient motion during a magnetic resonance protocol. According to some examples, the patient motion may be corrected or compensated.

Magnetic resonance imaging and motion detection

Techniques are disclosed for providing a first magnetic resonance fingerprinting dictionary using fingerprints having a first length. A transformation matrix is also utilized that is configured to shorten the fingerprints to a second length that is shorter than the first length. A second magnetic resonance fingerprinting dictionary may then be obtained by multiplying the first magnetic resonance fingerprinting dictionary with the transformation matrix, with the fingerprints of the magnetic resonance fingerprinting dictionary having the second length. This facilitates the storage of a MRF dictionary that takes up less storage space and decreases the time taken to perform scanning operations.

Magnetic resonance fingerprinting with dictionary recompression

A magnetic resonance fingerprinting (MRF) method for determining parameter values in pixels of an examination object can use a magnetic resonance system with, for example, a constant magnetic field strength (e.g. of less than 1.5 tesla or a constant magnetic field strength of less than 0.5 tesla). The MRF method can be adapted for conditions that prevail with such low-field magnetic resonance systems, thus enabling the parameter values to be advantageously determined efficiently while simultaneously maintaining a high degree of quality.

Low-field magnetic resonance fingerprinting

In a method and magnetic resonance apparatus for generating a Bmap of a region of interest, a magnetic resonance data set containing a number of image data sets is obtained and provided in a computer, wherein the image data sets are recorded using at least two measurement sequences and the mutually corresponding pixels of the image data sets each represent a time-dependent signal evolution. A Bmap of the region of interest is generated by the computer from the image data sets, wherein the Bvalue of a pixel of the Bmap is determined from the associated signal evolution.

Method and computer for producing a pulse sequence for controlling a magnetic resonance imaging apparatus

In a magnetic resonance fingerprinting method and apparatus for improved determination of local parameter values of an examination object, in which at least two signal comparisons of acquired picture element time series are carried out with comparison signal curves for determination of parameter values. A further (subsequent) signal comparison takes into account results of a preceding signal comparison. This multi-stage determination of parameter values allows an increase of the spatial resolution and the precision with which the parameter values can be determined.

In order to execute a low-artifact magnetic resonance fingerprinting (MRF) scan, a preferred order of N k-space trajectories of a sampling pattern is determined in a computer, along which in each case an undersampled scan data set is to be scanned, such that artifacts are avoided in parameter maps created from the scan data sets in an MRF scan. The order in which the N k-space trajectories are to be sampled one after the other is varied, so at least two different orders are produced. According to the orders that result due to this variation, determined test signal characteristics are compared with each other and/or with ideal signal characteristics with respect to their artifact behavior. A preferred order is determined from the resulting orders by taking into account the results of the comparison.

Method and apparatus for low-artifact magnetic resonance fingerprinting scan

In a method and apparatus for magnetic resonance (MR) fingerprinting, an MR signal is acquired from a subject by radiating radio-frequency (RF) energy that produces an RF transmission field that has a localized amplitude in the subject. The RF energy is radiated with an RF pulse configuration that maps the localized RF field amplitude in the phase of the MR signal from the subject. The detected MR signal is compared to a source of stored MR signal physical or theoretical models that respectively map different localized RF transmission field information in the respective phase thereof, the stored models being respectively for different substances. A substance in the subject from which the detected MR signal curve originated is identified by comparing the detected MR signal curve to the stored models to identify a best match.

Growing community of inventors

Erlangen, Germany

Gregor Koerzdoerfer