Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Siemens Healthineers Ag

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

Siemens Aktiengesell Schaft

Julius-maximilians-universitat Wurzburg

Andrew Dewdney

Ralf Ladebeck

Franz Schmitt

Johann Sukkau

Matthias Drobnitzky

Sabrina Harter

Stephan Biber

Jürgen Nistler

Stefan Stocker

Peter Dietz

Klaus Ludwig

Andreas Krug

Florian Steinmeyer

Rudi Baumgartl

Volker Schnetter

Manuel Stich

Gudrun Ruyters

Eva Eberlein

Jörg Rothard

Adrienne Campbell

Herbert Köstler

Simon Körber

Volker Weißenberger

Tobias Wech

Ronny Pflichtbeil

Axel Heitland

Bernhard Heinrich

Christiane Pfaff

Ludwig Eberler

Michael Leigart

The disclosure relates to a detector unit comprising a radio frequency antenna unit and a gradient coil unit surrounding the radio frequency antenna unit concentrically, each embodied as hollow cylinders surrounding a cylinder axis in the longitudinal direction. The detector unit comprises at least four shim units, which are embodied as oblong shapes and are each arranged in parallel to the cylinder axis at various positions in the circumferential direction on a first inner surface, with said first inner surface corresponding to the side of the gradient coil unit facing towards the cylinder axis, and forming raised areas in the direction of the cylinder axis. The detector unit comprises a fixing unit embodied for fixing the at least four shim units to the gradient coil unit, and an RF screen, which is arranged at least partly between the radio frequency antenna unit and the gradient coil unit.

Detector unit for a magnetic resonance device with gradient coil unit, shim unit, and radio-frequency antenna unit

A magnetic resonance tomography unit and a method for operating the magnetic resonance tomography unit are provided. The magnetic resonance tomography unit includes a plurality of magnetic field sensors arranged in an environment of the magnetic resonance tomography unit. The plurality of magnetic field sensors are configured to capture low-frequency magnetic fields in the environment of the magnetic resonance tomography unit and to transmit information about the magnetic fields to the controller via a signal connection. According to the method, fields for compensating the low-frequency magnetic fields are ascertained and output.

Magnetic resonance tomography unit and method for reducing image interference from low-frequency magnetic fields

According to one or more example embodiments, a shim apparatus for an MR apparatus includes a specimen holder, the specimen holder including a plurality of MR reference specimens, the MR reference specimens being on the specimen holder; a frame; a shaft, the shaft being mounted on the frame such that the shaft is rotatable about an axis of rotation, the specimen holder being non-rotatably connected to the shaft, the MR reference specimens being spaced apart from the axis of rotation; a drive unit, the drive unit being configured to output a torque, the drive unit being electrical or pneumatic; and a gear unit, the gear unit being configured to transfer the torque output by the drive unit to the shaft and to rotate or swivel the MR reference specimens about the axis of rotation.

Shim apparatus, method for using the shim apparatus and MR apparatus

A magnetic resonance device (), having a main magnet unit () with a cylindrical patient aperture (), wherein at least one radial gradient coil () is provided in the patient aperture () which generates a gradient field having, at least in regions, a radial gradient in relation to its own central axis parallel to the longitudinal axis of the patient aperture (), the radial gradient coil () being embodied as a cylinder coil.

Magnetic resonance device and method for recording magnetic resonance data using a magnetic resonance device

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

A method for improving shim pre-settings of a magnetic resonance device and a magnetic resonance device are provided. Efficient computation of shim settings for magnetic resonance imaging is provided by the method. The method includes loading of shim pre-settings from a database, creating shim settings using the shim pre-settings for recording magnetic resonance image data of an examination object by a magnetic resonance device, and activating a shim unit of the magnetic resonance device for recording the magnetic resonance image data. The method also includes using the created shim settings, improving the shim pre-settings using the created shim settings, and storing the improved shim pre-settings in the database.

Method for improving shim pre-settings of a magnetic resonance device

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

A method for determining a position of a mobile device relative to a B0 field magnet along a z-coordinate axis, and a device and a magnetic resonance tomography unit for performing the method are provided. The device includes a magnetic field strength sensor arranged in a fixed relative position. A characteristic magnetic field strength Bof the B0 field magnet that emerges for a plurality of x-y coordinate pairs with a same reference z-coordinate zis ascertained. The device is moved along the z-coordinate axis until the magnetic field strength sensor measures the characteristic magnetic field strength B.

Method and device for position determination in a magnetic resonance tomography unit

A magnetic resonance tomography system has a frequency control device for temperature compensation, a temperature sensor, and a high frequency generator. An output frequency of an output signal from the high frequency generator is dependent on a value of a digital frequency variable, and a synthesis signal with the system frequency is generated dependent on the output signal. A temperature change is detected using the temperature sensor, a temperature-time function of the temperature is determined using the temperature change that has been detected, a time is determined at which a change in the digital frequency variables in the least significant bit brings about a change in the frequency of the synthesis signal that corresponds with a change in the system frequency due to a temperature, according to the interpolated temperature-time function, and the digital frequency variable in the least significant bit is changed at the specified time.

Magnetic resonance tomography with slow temperature variation compensation

In a method, device and magnetic resonance apparatus for determining basic shim settings for shim elements of a magnetic resonance scanner of the apparatus, an optimization function is established in a processor, which includes multiple optimization parameters, including a first optimization parameter that designates a homogeneity value of a spatial distribution of the basic magnetic field in the scanner, and a second optimization parameter that designates a value of a force acting on the shim elements. The processor is configured to calculate the spatial distribution of the shim elements by minimizing the optimization function, dependent on the first and second parameters. Shim settings for the scanner are determined using the calculated spatial distribution of the shim elements.

Method and magnetic resonance apparatus for determining basic shim settings of the magnetic resonance apparatus

A magnetic resonance imaging (MRI) scanner includes a control device, a gradient coil for generating a gradient field, a gradient coil connector for connecting the gradient coil to the control device, and a temperature sensor. The temperature sensor is configured and disposed to detect a temperature of the gradient coil connector.

MRI scanner

A method for operating a mobile magnetic resonance tomography system having magnets and/or coils generating a magnetic field and a shield surrounding the magnets and/or coils is intended to enable an optimal image quality during the examination and at the same time have a small space requirement. For this purpose, a temperature is measured at a plurality of points on the shield by a temperature measuring system, where measured data of the temperature measuring system is sent to a compensation system, and where effects of temperature differences on the homogeneity of the magnetic field are compensated by the compensation system.

Mobile magnetic resonance tomography

A magnetic shield for a field magnet of a magnetic resonance system is provided. A magnet apparatus with a field magnet for a magnetic resonance system with active shielding and a magnetic shield, wherein the magnetic shield forms a hollow body which accommodates the field magnets is also provided. A wall of the hollow body has a first, a second and a third area, which are disposed along the axis. In this case the second area separates the first area and the third area from one another and has a smaller wall thickness than the first and the third area.

Magnetic shield for MR magnet

A patient support table for a magnetic resonance system with a magnetic field generation device creating a magnetic field of 7 T or more, comprising a table plate able to be moved into and out of the patient chamber of the magnetic resonance system by means of a drive device, characterized in that the drive device features a pneumatic cylinder with a piston which is coupled to the table plate, with the pneumatic cylinder featuring two working areas divided via the piston and able to be supplied separately with a working medium.

Patient support table for a magnetic resonance system having a strong magnetic field and a magnetic resonance system including such a patient support table

In a method for determination and evaluation of a shim parameter set for controlling a shim device in a magnetic resonance (MR) apparatus, the shim device is set using a first shim parameter set, a first field distribution is measured in a body region encompassing a target volume from which MR data are to be acquired, a second shim parameter set is determined using an algorithm for optimization of the field homogeneity in the target volume on the basis of the first shim parameter set and dependent on the first field distribution, a second field distribution is determined on the basis of the second shim parameter set, and the shim parameter sets are evaluated by indirect or direct comparison of the first field distribution and the second field distribution, in particular in the target volume.

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Neunkirchen am Brand, Germany

Andrew Dewdney