Siemens Healthcare Gmbh

The United States of America, As Represented by the Secretary, Department of Health and Human Services

University of Virginia Patent Foundation

Siemens Healthineers Ag

Julius-maximilians-universitat Wurzburg

Gudrun Ruyters

Markus Vester

Dominik Paul

Swen Campagna

Matthias Gebhardt

Gerhard Brinker

Wolfgang Bielmeier

Carsten Prinz

Bernd Erbe

Nikolaus Demharter

Jürgen Nistler

Juergen Nistler

Stephan Stoecker

Stephan Stöcker

Mario Zeller

Stefan Popescu

Thorsten Feiweier

Craig H Meyer

Berthold Kiefer

Stephan Kannengiesser

Josef Pfeuffer

Johann Sukkau

Daniel Niederlöhner

John P Mugler, Iii

Helmut Lenz

Andrew Dewdney

Robert Rehner

Michael Wullenweber

Axel Vom Endt

Michael Köhler

Manuel Stich

Samuel W Fielden

Stephan Kannengießer

Adam Kettinger

Adrienne Campbell

Herbert Köstler

Tobias Wech

Max Müller

Christiane Pfaff

A method for preparing magnetic resonance imaging of an object under examination is described. A plurality of representative pulse sequence segments are generated, each of which is associated with a reference gradient amplitude of the gradient pulse having the highest stimulation potential of the representative pulse sequence segment, and the stimulation potential of which is representative of a group of partially different pulse sequences. For each of the representative pulse sequence segments, a maximum gradient slew rate is determined for which a permitted maximum value of the stimulation potential is not exceeded. One of the representative pulse sequence segments is determined and selected, for a measurement protocol to be planned for a magnetic resonance imaging to be performed, according to the gradient amplitude of the gradient pulse having the highest stimulation potential of a pulse sequence segment of the pulse sequence on which the measurement protocol is based. The pulse sequence segment of the pulse sequence on which the measurement protocol is based is adjusted in such a way that a maximum gradient slew rate associated with the selected representative pulse sequence segment is also not exceeded by the pulse sequence segment of the pulse sequence on which the measurement protocol is based.

Preparing a magnetic resonance imaging method in compliance with stimulation-based limitations

A method and a system for providing parameters of a resonance frequency spectrum of a magnetic resonance scan. The system includes: an input interface for receiving a resonance frequency spectrum of a magnetic resonance scan and a computing device configured to implement a trained machine learning algorithm. The trained machine learning algorithm is trained to receive the resonance frequency spectrum received by the input interface as its input and to generate as its output a set of parameters of the resonance frequency spectrum. The system further includes an output interface configured to output the generated set of parameters.

System and method for providing at least one parameter for a magnetic resonance scan

Methods and systems for controlling patient stimulating effects in MR imaging. The methods and systems include calculating a first effective stimulus duration independently for each pulse flank of an MRI sequence individually and calculating a second effective stimulus duration for which a respective history of a changing gradient field during the sequence is taken into account. Dependent on an evaluation of both the first and second effective stimulus durations a threshold value for an allowable rate of change in the magnetic gradient field is then calculated. The respective MRI sequence is then evaluated against the calculated threshold value to determine whether or not the respective MRI sequence is safe to apply.

Method for controlling patient stimulating effects in magnetic resonance imaging, corresponding computer program and computer-readable storage medium, and magnetic resonance imaging device

The disclosure relates to a field camera and a method for measuring a magnetic field distribution using a magnetic resonance tomograph and the field camera. The field camera has a number of samples, which are distributed over a spatial volume to be measured, and a number of receive antennas. In an act of the method, a sensitivity matrix for the receive antennas, for each sample at each receive antenna, is captured using the magnetic resonance tomograph. In another act, antenna signals of the samples in a magnetic field to be measured are captured by the receive antennas, using the magnetic resonance tomograph. Finally, magnetic resonance signals of the individual samples are determined from the antenna signals as a function of the sensitivity matrix, using a controller. In a further act, the magnetic field strength at the location of the samples may be determined from the magnetic resonance signals.

Passive field camera and method for operating the passive field camera

A gradient system characterization function (e.g., a gradient system transfer function) may be developed by measuring a behavior of the MR device at a target temperature and developing at least one gradient system characterization function for a gradient coil of a magnetic resonance (MR) device at the target temperature based on the measured behavior. A patient may be subsequently imaged by the MR device, wherein the imaging process comprises measuring a temperature of a gradient coil, determining a gradient system characterization function at the measured temperature, calculating a pre-emphasized gradient of the gradient coil, and imaging the patient using the pre-emphasized magnetic field component.

Pre-emphasis techniques based on temperature dependent gradient system behavior for trajectory correction in magnetic resonance imaging

In a magnetic resonance apparatus and a method for operation thereof, at least one electrical operating value of at least one predetermined component of the apparatus is captured and, as a function of the at least one operating value, at least one coil operating value of a transmitting coil arrangement of the magnetic resonance apparatus is controlled for the purpose of limiting a B1 value.

Magnetic resonance apparatus and operating method therefor with monitoring and control of RF energy-relevant operating value

A phase difference caused by eddy currents is determined for an MR system. First MR data is acquired with a first sequence by irradiating at least one RF pulse having an RF excitation pulse, importing a first test gradient during or after the RF excitation pulse, applying a read-out gradient, and acquiring the first MR data while the read-out gradient is switched, so the first MR data is acquired for at least one K-space line. Second MR data is acquired with a second sequence by importing a second test gradient during or after the RF excitation pulse, and applying the read-out gradient. The second MR data is acquired while the read-out gradient is switched, so the second MR data is acquired for the at least one K-space line. The phase difference per voxel is determined using the first MR data and the second MR data.

Determining a phase difference caused by eddy currents for a magnetic resonance system

A method for monitoring a temporal change in a magnetic field in a magnetic resonance device, as well as an evaluation unit, a magnetic resonance device, and a computer program product for performing the method are provided. The method provides that a position-dependent magnetic field distribution that is produced by the plurality of gradient coils is provided with a plurality of monitoring points. In addition, time-dependent gradient values of the plurality of gradient coils are ascertained. Based on position-dependent magnetic field distribution and the time-dependent gradient values, the temporal change in the magnetic field is ascertained. The temporal change in the magnetic field is monitored by comparing the temporal change in the magnetic field with at least one limit value.

Monitoring of a temporal change in a magnetic field in a magnetic resonance device

In some aspects, the disclosed technology relates to magnetic field monitoring of spiral echo train imaging. In one embodiment, a method for spiral echo train imaging of an area of interest of a subject includes measuring k-space values and field dynamics corresponding to each echo of a spiral echo pulse train, using a dynamic field camera and a magnetic resonance imaging (MRI) system. The dynamic field camera is configured to measure characteristics of fields generated by the MRI system; the characteristics include at least one imperfection associated with the MRI system. The spiral echo pulse train corresponds to a spiral trajectory scan from the MRI system that obtains magnetic resonance imaging data using a pulse sequence which applies spiral gradients in-plane with through-plane phase encoding. The method also includes generating, based on the characteristics of the fields measured by the dynamic field camera and based on the obtained magnetic resonance imaging data, a model of the k-space trajectory corresponding to each echo of the spiral echo pulse train; and, based on the generated model of the k-space trajectory, reconstructing images that correspond to the area of interest and that are compensated for the at least one imperfection associated with the MRI system.

Magnetic field monitoring of spiral echo train imaging

In a magnetic resonance (MR) apparatus and an operating method therefor, a sequence with which the MR data are to be recorded is created in or provided to a control computer of the MR apparatus. A maximum RF output and a maximum gradient performance of the scanner magnetic resonance apparatus during the performance of the sequence are determined by simulating or analyzing the performance of the sequence in the control computer, and it is verified whether the maximum RF output and/or the maximum gradient performance violate predetermined limit values. Execution of the sequence to record the MR data is performed only if the verification showed that the limit values are not violated.

Method and magnetic resonance apparatus wherein limit values are observed when recording magnetic resonance data

A method for operating a magnetic resonance apparatus by a safety unit, taking into account persons fitted with an implant, a safety unit, a safety system, a magnetic resonance apparatus, and a computer program product are provided. The magnetic resonance apparatus includes a first part and a second part. The first part is operated separately from the second part and includes the safety unit. During an examination of a person fitted with an implant, the safety unit checks that the magnetic resonance apparatus, in a restricted operating mode, is complying with implant-conformant limit values.

Operation of a magnetic resonance apparatus taking into account persons fitted with implants

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Erlangen, Germany

Gudrun Ruyters