Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Siemens Healthineers Ag

The General Hospital Corporation

Siemens Aktiengesell Schaft

Andreas Krug

Peter Dietz

Stephan Biber

Axel Vom Endt

Michael Mallett

Stefan Popescu

Stefan Stocker

Johann Schuster

Matthias Gebhardt

Ralph Kimmlingen

Andreas Greiser

Thorsten Speckner

Adrian Mark Thomas

Eva Eberlein

Mark James Le Feuvre

Annette Lohfink

Wolfgang Renz

Jürgen Nistler

Lawrence Leroy Wald

Razvan Lazar

Ludwig Eberler

Lars Lauer

Andrew Dewdney

Michael Köhler

Karsten Wicklow

Michael Eberler

Annette Stein

Graham Hutton

Sascha Fath

Simon Körber

Mathias Davids

Marco Bevilacqua

Joerg Riegler

Christopher Stroehlein

Christopher Ströhlein

A method for calibrating gradient amplifiers of a magnetic resonance apparatus is provided. The magnetic resonance apparatus includes one or more gradient coils that include at least two coil segments configured to generate a gradient magnetic field with a gradient in a spatial direction, and a gradient amplifier for each of the at least two coil segments. The gradient amplifier is configured to supply the respective coil segment with electric current. A plurality of magnetic field distributions are measured, each being generated via at least one coil segment of the at least two coil segments. For measuring each magnetic field distribution of the plurality of magnetic field distributions, the at least one coil segment that generates the respective magnetic field distribution is supplied with a predetermined electric current via the respective gradient amplifier. The gradient amplifiers are calibrated via a comparison of the plurality of measured magnetic field distributions.

Method for calibrating gradient amplifiers of a magnetic resonance apparatus, magnetic resonance apparatus, and computer program product

A gradient coil unit may include a hollow cylinder surrounding a cylinder axis, delimited perpendicularly to the cylinder axis by a first longitudinal end and a second longitudinal end opposing the first longitudinal end. The hollow cylinder may include a first hollow cylinder region and a second hollow cylinder region separated from the first hollow cylinder region by a sectional plane perpendicular to the cylinder axis. The first hollow cylinder region may be delimited by the first longitudinal end and the second hollow cylinder region by the second longitudinal end. The gradient coil unit may also include a conductor structure configured to generate magnetic field gradients in three mutually different directions. The gradient coil unit may have a length corresponding to a distance between the first longitudinal end and the second longitudinal end of at least 140 cm.

Gradient coil unit comprising two hollow cylinder regions

A magnetic resonance imaging device may include a field generator configured to provide a magnetic field in an imaging volume of the magnetic resonance imaging device. The field generator may include at least one magnet that confines the imaging volume in at least one spatial direction. The at least one magnet may be curved in such a way that a perpendicular distance between a line oriented along a direction of access to the imaging volume and a surface directed towards the imaging volume of the at least one magnet varies in the direction of access to the imaging volume.

Magnetic resonance imaging device with a curved field generation unit

A magnetic resonance imaging device may include a field generator for generating at least one magnetic gradient field. The field generator may include a first magnet and a second magnet confining an imaging volume of the magnetic resonance imaging device in two spatial directions. The first magnet and the second magnet may be arranged asymmetrically with respect to the imaging volume. The magnetic resonance imaging device may be used to perform a method for acquiring an image of a diagnostically relevant body region of a patient.

Magnetic resonance imaging device with asymmetric field generation unit

A magnetic resonance imaging device having a field generation unit configured to provide a magnetic field in an imaging volume of the magnetic resonance imaging device. The field generation unit has at least one magnet. A surface of the field generation unit directed towards the imaging volume of the at least one magnet has a concave shape, wherein a direction of access to the imaging volume is oriented essentially perpendicular to a main direction of magnetic field lines in the imaging volume.

Magnetic resonance imaging device with a concave-shaped field generation unit

A device for use in magnetic resonance imaging (MRI) systems may include a superconducting main magnet coil; and a thermal radiation shield that encloses the superconducting main magnet coil. The shield may include an inner cylindrical bore tube, an outer cylindrical wall, and annular end walls welded between the annular cylindrical bore tube and the outer cylindrical wall to form a closed, hollow cylindrical vessel. A distribution of a position and length of welds that affix the annular end walls to the inner cylindrical bore tube may include a predetermined arrangement of welds of varying lengths interspersed with gaps of varying lengths.

Apparatus for magnetic resonance imaging, and methods for the design and manufacture thereof

A method for determining peripheral nerve stimulation during MR imaging of a patient in a MR scan unit for a MR pulse sequence is described. In the method, a plurality of model-based candidate stimulations are determined dependent on a unit vector potential of the gradient magnet field generated during MR imaging and dependent on candidate data models for different object parameter values. A model-based candidate data stimulation is selected as a stimulation model for the patient dependent on an individual patient model. A distribution of a vector potential of a gradient magnetic field acting on the patient is determined as a function of a unit gradient current for a determined position of the patient in the MR scanning unit. The nerve stimulation of the patient is determined for the determined position based on the selected candidate stimulation and a gradient current of a gradient pulse of the MR pulse sequence.

Patient-model-based determination of a stimulation of a magnetic resonance imaging

A gradient coil unit including a first conductor structure arranged within a first form and a second conductor structure arranged within a second form, wherein the first conductor structure and the second conductor structure are designed together to generate a magnetic field gradient in a first direction, the first form and the second form are arranged separately, opposite each other, and divided by a hollow space, and the first form has a segment of a circle as a cross section.

Non-cylindrical gradient coil unit

A magnetic resonance device comprising a gradient coil assembly having gradient coils is described. The gradient coils are supported by at least one cylindrical coil carrier for generating gradient fields. As part of the gradient coil assembly, at least one vibration sensor is provided for measuring vibrations of the gradient coil assembly at least in a radial direction of oscillation.

Magnetic resonance device, magnetic resonance system and associated operating method

A magnetic resonance system includes a magnet device, which is arranged in an outer housing and an inner housing located therein. A monitoring method includes determining a value of a vibration amplitude of the outer housing or an intermediate housing located between the inner housing and the outer housing at a vibration frequency; providing a transmission ratio between the vibration amplitude and the operating parameter at the vibration frequency; and determining a value of the operating parameter as a function of the determined value of the vibration amplitude by means of the transmission ratio.

Monitoring an MR magnet using vibrations

A gradient coil for magnetic resonance imaging has at least two conductors that are independent of one another, designed to jointly generate a magnetic field gradient and a magnetic field of a higher order in the examination region of a magnetic resonance scanner.

Magnetic resonance gradient coil for generating a magnetic field gradient and a magnetic field of a higher order

In a method for actuating a shim coil arrangement of a magnetic resonance data acquisition scanner that has a shim controller that operates said shim coil arrangement, and a gradient coil arrangement operated by a gradient controller, the gradient controller determine a gradient pulse shape, in accordance with specifications of a magnetic resonance data acquisition sequence, that is activated by the gradient coil arrangement, when the sequence is executed in said scanner. A modifies the gradient pulse shape and provides the modified gradient pulse shape to the shim controller and the shim controller generates shim settings dependent on the modified gradient pulse shape, and actuates said shim coil arrangement according to the shim settings during activation of the gradient pulse shape by the gradient coil arrangement during execution of the sequence in said scanner.

Method, computer and magnetic resonance apparatus for controlling shimming of the basic magnetic field

In a method and an apparatus for magnetic resonance tomography, an eddy current field is compensated by taking into account its progression over time and its dependence on a sensed value, by having a sensor determine the sensed value and, on the basis of the sensed value, a current strength for a conductor in order to generate an opposing field to reduce the eddy current field is determined, and supplied to the conductor.

Method and apparatus for eddy current field compensation in magnetic resonance tomography

A connecting device for a magnetic system of an imaging system includes a holding element for connection of the connecting device to a power supply connection of the magnetic system, and a connecting element for connection of the connecting device to a power supply cable for operation of the magnetic system. The connecting device also includes an oscillation damping device having a spring element. The oscillation damping device is operable to dampen oscillations of the magnetic system that act on the connecting device by way of the holding element, with respect to the connecting element.

Connecting device for a magnetic system of an imaging system

The present embodiments relate to a method for reducing mechanical vibrations in a magnetic resonance imaging system that includes a gradient system having a gradient coil body and an electrically conductive shroud that at least partly encloses the gradient coil body. The method includes determining a mechanical natural vibration mode of the gradient coil body in the magnetic resonance imaging system, and determining excitation force components for the natural vibration mode. The method also includes determining electrically conductive areas of the gradient system, which during operation of the magnetic resonance imaging system, generate a Lorentz force component that contributes to the excitation force components. The method further includes modifying the determined electrically conductive areas such that a minimal number of the Lorentz force components coincide with the excitation force components.

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Fuerth, Germany

Andreas Krug