Abstract: A gradient coil unit surrounding a cylindrical patient receiving region and including a hollow cylindrical primary coil and a hollow cylindrical secondary coil surrounding the primary coil and the patient receiving region in a coaxial manner, having a first longitudinal end in a longitudinal direction, which is designed to receive an examination object, and a second longitudinal end lying opposite the first longitudinal end in the longitudinal direction, the primary coil having a first length in the longitudinal direction delimited by a first longitudinal position facing the first longitudinal end, and a second longitudinal position, the secondary coil having a second length delimited by a third longitudinal position facing the first longitudinal end, and a fourth longitudinal position, wherein the first length is shorter than the second length and the first longitudinal position has a greater spacing with respect to the first longitudinal end than the third longitudinal position.

Abstract: 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.

Abstract: A magnetic resonance device for acquiring magnetic resonance data of an object, the magnetic resonance device including a main magnet operable to provide a main magnetic field along at least one surface of the main magnet, wherein the main magnet comprises: a first magnet segment; a second magnet segment; and a cavity to accommodate the second magnet segment, wherein the second magnet segment is arranged in the cavity of the main magnet, and wherein the second magnet segment is variably positioned and/or oriented relative to the first magnet segment to adjust a magnetic field contribution of the second magnet segment to the main magnetic field.

Abstract: A gradient coil assembly for a magnetic resonance imaging device is disclosed. The gradient coil assembly comprises a cylindrical carrier with conductors forming three gradient coils associated with three orthogonal physical gradient axes. The cylindrical carrier comprises at least two radial through openings at different angular positions. At least one of the conductors runs through at least one area of the carrier located circumferentially between the through openings.

Abstract: 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.

Abstract: 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.

Abstract: Techniques are disclosed relating to a cable connection unit for connection to a gradient coil unit, which includes at least one first electric conductor and one second electric conductor. The first electric conductor and the second electric conductor may be arranged at least partially next to one other, and be connected to one another via a load-carrying connection.

Abstract: 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.

Abstract: Techniques are disclosed relating to a cable connection unit for connection to a gradient coil unit, which includes at least one first electric conductor and one second electric conductor. The first electric conductor and the second electric conductor may be arranged at least partially next to one other, and be connected to one another via a load-carrying connection.

Abstract: A shim coil arrangement is provided for a magnetic resonance tomography system. The shim coil arrangement includes a printed circuit board, a plurality of spacers, and at least one shim coil. The plurality of spacers are arranged on the printed circuit board. The at least one shim coil is arranged on the printed circuit board.

Abstract: A shim coil arrangement for a magnetic resonance tomography system includes one or more spacers.

Abstract: The present embodiments relate to a magnetic resonance tomography system having a basic-field field generation device for generating a basic magnetic field. The magnetic resonance tomography system also includes a gradient-field field generation device for generating a gradient field, where the basic-field field generation device and the gradient-field field generation device are arranged in an evacuatable low-pressure housing.

Abstract: 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.

Abstract: In one embodiment a method for processing a reconstruction image is disclosed. The method includes recording the reconstruction image by a magnetic resonance device having a gradient coil to generate a gradient field. The method further includes distortion-correcting the reconstruction image. The method further includes back-transforming the distortion-corrected reconstruction image, by an image processing device, into a distortion-uncorrected reconstruction image, the back-transforming uses an algorithm having a first input value describing a real gradient field given at a real measuring point of the signal.

Abstract: A magnetic resonance apparatus has a cylindrical gradient coil with an x-gradient coil and a y-gradient coil that are asymmetrical relative to the z-direction of a coordinate system, the z-direction extending along a longitudinal direction of a patient receptacle. Shim coils are provided that generate magnetic fields to homogenize the basic magnetic field, produced by a cylindrical basic field magnet, in an examination volume in the patient receptacle. At least some of the shim coils are asymmetrical relative to the z-direction to minimize coupling induction between the asymmetrical x-gradient coil and y-gradient coil and the asymmetrical shim coils.

Abstract: In one embodiment a method for processing a reconstruction image is disclosed. The method includes recording the reconstruction image by a magnetic resonance device having a gradient coil to generate a gradient field. The method further includes distortion-correcting the reconstruction image. The method further includes back-transforming the distortion-corrected reconstruction image, by an image processing device, into a distortion-uncorrected reconstruction image, the back-transforming uses a first algorithm or a second algorithm including a second input value associated with the measurement signal, the second input value being a fictitious gradient field value associated with a distorted measuring point at which the measurement signal is processed, and the second input value is raised or lowered by a nonlinear field component of the real gradient field compared with a linear ideal gradient field.

Abstract: The method for determination of the design of the basic magnet of a magnetic resonance apparatus with at least one gradient coil system, the design of the basic magnet is determined by taking into consideration forces acting on the at least one gradient coil system that may lead to vibrations of the gradient coil system due to switching processes of the gradient coil system in the field of the basic magnet.

Abstract: A magnetic resonance apparatus has a cylindrical gradient coil with an x-gradient coil and a y-gradient coil that are asymmetrical relative to the z-direction of a coordinate system, the z-direction extending along a longitudinal direction of a patient receptacle. Shim coils are provided that generate magnetic fields to homogenize the basic magnetic field, produced by a cylindrical basic field magnet, in an examination volume in the patient receptacle. At least some of the shim coils are asymmetrical relative to the z-direction to minimize coupling induction between the asymmetrical x-gradient coil and y-gradient coil and the asymmetrical shim coils.

Abstract: 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.

Abstract: The method for determination of the design of the basic magnet of a magnetic resonance apparatus with at least one gradient coil system, the design of the basic magnet is determined by taking into consideration forces acting on the at least one gradient coil system that may lead to vibrations of the gradient coil system due to switching processes of the gradient coil system in the field of the basic magnet.