Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Eva Eberlein

Ralph Kimmlingen

Wolfgang Renz

Johann Schuster

Matthias Gebhardt

Franz Schmitt

Andreas Krug

Jürgen Nistler

Stefan Stocker

Razvan Lazar

Ludwig Eberler

Helmut Lenz

Andrew Dewdney

Axel Vom Endt

Guenther Pausch

Heinz Hentzelt

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 gradient pulse generator generates reference current signals for a plurality of gradient coils of a gradient coil system of a magnetic resonance system and supplies each of the reference current signals to a controller assigned to one of the gradient coils. Also supplied to the respective controller is an actual current signal that is characteristic of the current flowing in the respective gradient coil. Each of the controllers generates a control signal and accordingly drives a gradient power amplifier assigned to the respective gradient coil. The gradient power amplifiers apply a current to the gradient coils assigned to the gradient power amplifiers in accordance with the generated control signals. Each of the controllers is also supplied with the reference current signal or the actual current signal of at least one other gradient coil or the time derivative of the reference current signal or the actual current signal.

Controlling gradient coils taking the inductive coupling into account

A controller of a magnetic resonance system determines an activation signal vector based on a target field predetermined for the controller in conjunction with field characteristics of field coils known to the controller. The activation signal vector includes a respective activation signal for each field coil. The controller determines the activation signal vector such that within a predetermined examination volume of the magnetic resonance system, any deviation of an ideal field that would result if ideal coils were subjected to the activation signals of the activation signal vector from the target field is minimized. The controller determines a compensation signal vector based on the activation signal vector in conjunction with eddy current characteristics of the field coils known to the controller. The compensation signal vector is used to minimize a deviation of an actual field from the target field within the predetermined examination volume of the magnetic resonance system.

Activation of field coils of a magnetic resonance system having eddy current compensation

An optimization of a magnetic resonance apparatus is achieved by a device and a method to generate a gradient field in a magnetic resonance apparatus, wherein a field directed in a first direction is generated by a first flat/saddle coil cooling system, a field directed in an additional direction is generated by an additional flat/saddle coil cooling system, and wherein a gradient field pointing in a direction is composed of at least the field generated by the first flat/saddle coil cooling system and the field generated by the additional flat/saddle coil cooling system.

Optimized flat/saddle coil cooling system

A detector unit for arrangement in a field generating unit of a magnetic resonance device has an RF transmission/reception system for transmitting RF pulses into, or receiving magnetic resonance signals from, an examination volume of the field generation unit. The RF transmission/reception system surrounds a patient tunnel at a radial distance from a tunnel axis thereof, and is divided into two sub-systems located at a distance from each other along the direction of the tunnel axis, so as to form a substantially annular cavity or interstice therebetween.

Detector unit for arrangement within a field generating unit of an MR device

Disclosed is a vacuum housing for a magnetic resonance apparatus having a recess for leading through lead wires to elements located inside the vacuum housing, and a first lead-through bushing module. The first lead-through bushing module is provided with a first closing plate which is configured so as to vacuum-tightly seal the recess along with a second closing plate. The first bushing module is also provided with a first structural component that is to be at least partially led through the recess during assembly of the lead-through bushing module and whose size defines a minimum size of the recess, which is greater than the size of the first closing plate.

Vacuum housing for a magnetic resonance apparatus

A generator of time-variable magnetic fields generator for a magnetic resonance apparatus has a primary gradient coil unit for generating of a gradient magnetic field in an examination region of the magnetic resonance apparatus. The primary gradient coil unit, for accommodating at least one gradient coil conductor, has a central region, an outer region and at least one connecting region connecting the two regions. The outer region surrounds the central region. At least one intervening space is disposed between the central region and the outer region. The intervening space is free of the gradient coil conductors of the primary gradient coil unit and a radio frequency antenna element is disposed therein. Such a generator enables an effective gradient field and RF field generation in a compact design combining a gradient coil and a radio-frequency antenna.

Time-variable magnetic fields generator and magnetic resonance apparatus embodying same

A switchable gradient coil system is composed of saddle coils that can be operated respectively as primary coils or auxiliary coils. The auxiliary coils for one gradient axis, which exhibit a reduced subtended angle compared to the primary coils, are arranged in the gaps between coils that are arranged diametrically opposite each other in a radial plane for the other gradient axis.

Switchable gradient coil system formed by saddle coils

A local gradient coil arrangement having an essentially hollow-cylindrical geometry can be separated at at least one side along a separating line proceeding in the axial direction of the arrangement. All gradient coil conductors that would cross the separating line are interrupted at the separating line. The currents at each side of the separating line are carried via connecting lines that proceed parallel to the separating line. The gradient coil arrangement can thus be divided into two parts without having to provide contacts between these two parts.

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Baiersdorf, Germany

Eva Eberlein