Patent application number | Description | Published |
20090192382 | MAGNETIC RESONANCE SYSTEM, ANTENNA SYSTEM, METHOD FOR DESIGNING A MAGNETIC RESONANCE SYSTEM AND METHOD TO GENERATE MAGNETIC RESONANCE EXPOSURES - A magnetic resonance system obtaining magnetic resonance exposures of an examination subject, has an examination tunnel, a whole-body antenna with two connection terminals. The whole-body antenna cylindrically extends around the examination tunnel along a longitudinal axis. The system has a radio-frequency supply device in order to respectively supply the whole-body antenna with radio-frequency signals for emission of a radio-frequency field in the examination tunnel. The radio-frequency supply device has a radio-frequency generator for generation of a radio-frequency signal, a signal splitter that divides a radio-frequency signal coming from the radio-frequency generator into two partial signals that are phase-shifted by 90° relative to one another. Two radio-frequency feed lines are connected with the two connection terminals of the whole-body antenna. Via these radio-frequency feed lines, the two partial signals are fed into the whole-body antenna. The whole-body antenna has an intrinsic transmission characteristic such that a radio-frequency field is emitted that is elliptically polarized in a defined manner in a plane lying perpendicular to the longitudinal axis (at least in the unloaded state of the examination tunnel). | 07-30-2009 |
20100286802 | METHOD TO OPERATE AN IMAGING SYSTEM, AND IMAGING SYSTEM - In an imaging system having a number of subsystems and a control device that controls the subsystems in a coordinated manner to implement a measurement sequence and an operating method therefor, sequence control data that define different functional sub-sequences of the measurement sequence are transmitted to the control device. Different active volumes are associated with the functional sub-sequences. In addition to the sequence control data, active volume position data are provided to the control device that define bearing and extent of the active volumes associated with the different functional sub-sequences. Control signals to implement the measurement sequence for the different subsystems are generated automatically by the control device based on the sequence control data and the active volume position data so that the individual functional sub-sequences are locally optimized at least with regard to a sub-region of their associated active volume. | 11-11-2010 |
20110043204 | MAGNETIC RESONANCE SYSTEM AND METHOD FOR COMPUTERIZED RULE-BASED CONTROL THEREOF - In a magnetic resonance system according to a measurement protocol defined in advance and comprising multiple acquisition parameters, wherein given a non-compliance with at least one limit value (which is automatically established before the beginning of a subject-specific measurement data acquisition)—in particular a SAR limit value and/or a magneto-stimulation limit value and/or a hardware limit value—by the measurement protocol, an adaptation of at least one acquisition parameter ensues using at least one (in particular user-defined) protocol-specific rule for compliance with the limit value, and the measurement data acquisition ensues automatically according to the adapted acquisition parameters. | 02-24-2011 |
20110187367 | METHOD AND MAGNETIC RESONANCE SYSTEM TO REDUCE DISTORTIONS IN DIFFUSION IMAGING - In a method and magnetic resonance apparatus to reduce distortions in magnetic resonance diffusion imaging, a magnetic resonance data acquisition system is operated to acquire magnetic resonance data in a first measurement with a first diffusion weighting, and to acquire magnetic resonance data in a second measurement with a second, different diffusion weighting. A non-linear, system-specific distortion-correcting function is determined on the basis of system-specific information that is specific to said magnetic resonance data acquisition system. Correction parameters are calculated to correct distortions in subsequently-acquired diffusion-weighted magnetic resonance images, based on the data acquired in the first and second measurements with the system-specific distortion-correcting function applied thereto. The subsequently-acquired diffusion-weighted magnetic resonance images are corrected using the correction parameters to at least reduce distortions therein. | 08-04-2011 |
Patent application number | Description | Published |
20080197850 | MAGNETIC RESONANCE APPARATUS HAVING A SUPERCONDUCTING BASIC FIELD MAGNET WITH A STRUCTURALLY REINFORCED CRYOSHIELD - In an arrangement of a basic field magnet and a gradient coil of a magnetic resonance apparatus, the basic field magnet includes superconducting coils that are arranged in a reservoir with liquid helium for cooling. The helium reservoir is surrounded by a further reservoir, designated as an outer vacuum chamber. A vacuum exists between the outer vacuum chamber and the helium reservoir. A cryoshield is arranged between the outer vacuum chamber and the helium reservoir. The gradient coil is arranged in the inner chamber of the basic field magnet. The cryoshield has additional structure for reinforcement that counteract vibrations of the cryoshield. | 08-21-2008 |
20080265888 | MAGNETIC RESONANCE APPARATUS WITH A SUPERCONDUCTING BASIC FIELD MAGNET WITH AN ELECTRICALLY CONDUCTIVE COATING ON THE OUTER VACUUM CHAMBER - In an arrangement with a basic field magnet and with a gradient coil of a magnetic resonance apparatus, the basic field magnet includes superconducting coils that are arranged in a reservoir with liquid helium for cooling. The helium reservoir is surrounded by a further reservoir, designated as an outer vacuum chamber. A vacuum exists between the outer vacuum chamber and the helium reservoir. A cryoshield is arranged between the outer vacuum chamber and the helium reservoir. The gradient coil is arranged in the inner chamber of the basic field magnet. The outer vacuum chamber has an additional coating with a high electrical conductivity. | 10-30-2008 |
20090146657 | Method for processing a distortion-corrected 2d or 3d reconstruction image recorded by a magnetic resonance device - In one embodiment of the present invention, a method for processing a 2D or 3D reconstruction image is disclosed which is recorded by a magnetic resonance device, including a gradient coil that generates a gradient field, and is distortion—corrected with regard to a given non-linearity—leading to an image distortion—of the gradient field using an algorithm that processes the measurement signals at different measurement points lying in the imaging volume, which algorithm, with respect to each signal processed by it, processes the first input value describing the real gradient field given at the real measurement point of the signal, in which method, for inverse transformation of the distortion-corrected reconstruction image into a distortion-uncorrected reconstruction image, use is made of the first algorithm or a second algorithm corresponding to the first algorithm, which, with respect to each signal processed by it, is given as second input value such a value which describes a fictitious gradient field at the respective distorted measurement point at which the processed signal appears, which is increased or decreased by the non-linear field component of the real gradient field compared with the linear ideal gradient field. | 06-11-2009 |
20100266186 | Method for processing a distortion-corrected 2D or 3D reconstruction image recorded by a magnetic resonance device - In one embodiment of the present invention, a method for processing a 2D or 3D reconstruction image is disclosed which is recorded by a magnetic resonance device, including a gradient coil that generates a gradient field, and is distortion-corrected with regard to a given non-linearity—leading to an image distortion—of the gradient field using an algorithm that processes the measurement signals at different measurement points lying in the imaging volume, which algorithm, with respect to each signal processed by it, processes the first input value describing the real gradient field given at the real measurement point of the signal, in which method, for inverse transformation of the distortion-corrected reconstruction image into a distortion-uncorrected reconstruction image, use is made of the first algorithm or a second algorithm corresponding to the first algorithm, which, with respect to each signal processed by it, is given as second input value such a value which describes a fictitious gradient field at the respective distorted measurement point at which the processed signal appears, which is increased or decreased by the non-linear field component of the real gradient field compared with the linear ideal gradient field. | 10-21-2010 |
Patent application number | Description | Published |
20130038329 | MAGNETIC RESONANCE SYSTEM HAVING VARIABLE FREQUENCY TRANSMIT PULSES - A controller of a magnetic resonance system outputs a low frequency base signal to a conversion device. While outputting the base signal to the conversion device, the controller outputs an oscillator control signal to an oscillator. The oscillator outputs a frequency signal corresponding to the oscillator control signal to the conversion device. The conversion device converts the frequency signal into a high frequency transmit pulse with the aid of the base signal and outputs the transmit pulse to a magnetic resonance transmit antenna. The magnetic resonance transmit antenna applies a high frequency field corresponding to a transmit pulse to an examination volume of the magnetic resonance system. The controller varies the oscillator control signal output to the oscillator while outputting the base signal to the modulator. The transmit pulse) has a larger bandwidth than the base signal. | 02-14-2013 |
20130082705 | MAGNETIC RESONANCE SYSTEM AND METHOD FOR TIME SYNCHRONIZATION OF DIFFERENT COMPONENTS OF A MAGNETIC RESONANCE SYSTEM - A method for time synchronization of various components of a magnetic resonance system includes generating a series of amplitude-modulated radio-frequency pulses and associated gradient fields to deflect the magnetization of a slice detecting at least two spin signals, determining a phase difference between two of the spin signals, processing the phase difference in order to determine at least one time shift between two of the following variables that are generated by different components of the magnetic resonance system, an envelope of the amplitude-modulated radio-frequency pulses, a radio-frequency portion of the amplitude-modulated radio-frequency pulses, and one or more gradient fields, and synchronizing the associated components of the magnetic resonance system depending on the at least one time shift. | 04-04-2013 |
20130082707 | Method for the Control of a Magnetic Resonance System - A method for the control of a magnetic resonance system is provided. In a test phase before a magnetic resonance measurement, a test high-frequency pulse with several parallel individual high-frequency pulses is transmitted with a transmitter antenna arrangement over various different high-frequency transmitter channels. At lower transmitter power, the test high-frequency pulse generates essentially the same field distribution as an excitation high-frequency pulse to be transmitted during a subsequent magnetic resonance measurement. A high-frequency field generated by this test high-frequency pulse is measured in at least one area of a local pulse arrangement, and on the basis of the high-frequency field measured, a high-frequency field value that is to be anticipated at the local coil arrangement during the subsequent magnetic resonance measurement is determined. The control of the magnetic resonance system during a later magnetic resonance measurement includes taking the high-frequency field value into account. | 04-04-2013 |
20130127462 | Method for Operating a Receiving Device for Magnetic Resonance Image Signals of a Body - A receiving device for magnetic resonance (MR) image signals of a body is operated in an MR system such that for at least one coil element of the receiving device, a space domain, in which a spatial sensitivity of the coil element satisfies a predetermined criterion, is determined. A center frequency and a bandwidth of the MR image signal radiated by the body in the space domain are determined for the space domain. A receive path disposed downstream of the coil element is parameterized for operation at the determined center frequency and with the determined bandwidth. | 05-23-2013 |
20130214784 | Method for Operating a Coil and a Monitoring Module - A method for operating a coil, through which a varying current flows, is provided. Mechanical resonance responses of the coil are recorded and are modeled by an electrical resonant circuit model. A check is made as to whether a varying current that is to be sent through the coil evokes a resonant response in the electrical resonant circuit model. The current flow through the coil is blocked if the resonant response exceeds a predefined limit value. | 08-22-2013 |
20130221965 | B1 Field-Based Regulation Within a Sequence for NMR - A B1 magnetic field may be regulated during a magnetic resonance tomography (MRT) imaging sequence. | 08-29-2013 |
20130229180 | Emission of High Frequency Pulses in a Magnetic Resonance Tomography System - A method for emitting a sequence of high frequency pulses that may have different envelopes in a magnetic resonance tomography system is provided. A digital instruction signal that specifies the envelope for the high frequency pulses that are to be emitted is received. A digital control signal is transmitted to a high frequency unit for generating high frequency pulses, depending on the instruction signal. A test signal that allows notification of a current overload situation is received. The current control signal is reduced if the test signal indicates an overload situation. | 09-05-2013 |
20130257426 | Activating a Magnetic Resonance System - A method for activating a magnetic resonance system having a transmit antenna arrangement is provided. The transmit antenna arrangement includes a plurality of independent high-frequency transmit channels with a respectively assigned transmit antenna. Each high-frequency transmit channel has a controllable oscillator. The individual high-frequency transmit channels are activated with independent transmit pulses, and a frequency of the controllable oscillators is controlled independently. At least two of the controllable oscillators therefore oscillate in different frequencies. | 10-03-2013 |
20130307538 | MAGNETIC RESONANCE SYSTEM AND METHOD TO CONTINUOUSLY CORRECT PHASE ERRORS OF A MAGNETIC RESONANCE MEASUREMENT SEQUENCE - In a method and magnetic resonance system to correct phase errors in multidimensional, spatially selective radio-frequency excitation pulses in a pulse sequence used to operate the system to acquire magnetic resonance data, a multidimensional, spatially selective radio-frequency excitation pulse is radiated and multiple calibration gradient echoes are acquired. A phase correction and a time correction of the multidimensional, spatially selective radio-frequency excitation pulse is then calculated. | 11-21-2013 |
20130307539 | MAGNETIC RESONANCE SYSTEM AND METHOD TO CONTINUOUSLY CORRECT PHASE ERRORS OF A MAGNETIC RESONANCE MEASUREMENT SEQUENCE - In a method and magnetic resonance apparatus to continuously correct phase errors in a magnetic resonance measurement sequence in which multiple sequentially radiated, multidimensional, spatially-selective radio-frequency excitation pulses are used, multiple calibration gradient echoes are acquired in a calibration acquisition sequence and a correction value for a phase response and a correction value for a phase difference are calculated from the multiple calibration gradient echoes. Furthermore, an additional radio-frequency excitation pulse is radiated takes into account the correction values. | 11-21-2013 |
20130320977 | METHOD AND APPARATUS TO DETERMINE A SUBJECT-SPECIFIC B1 DISTRIBUTION OF AN EXAMINATION SUBJECT IN A MEASUREMENT VOLUME OF A MAGNETIC RESONANCE APPARATUS - In a magnetic resonance method and apparatus to determine a subject-specific B1 distribution of an examination subject in a measurement volume in the magnetic resonance apparatus, a first measurement data set of the examination subject is acquired using a first pulse sequence, a second measurement data set of the examination subject is acquired using a second pulse sequence, and a third measurement data set of the examination subject is acquired using a third pulse sequence. A first phase is determined from the first measurement data set, a second phase from the second measurement data set and a third phase from the third measurement data set. A relevant phase shift is calculated from the first phase, the second phase and the third phase, and the B1 distribution are determined from the calculated relevant phase shift. | 12-05-2013 |
20140218021 | METHOD AND MAGNETIC RESONANCE SYSTEM TO ACQUIRE MR DATA AND TO DETERMINE A B1 MAGNETIC FIELD - In a method to acquire magnetic resonance (MR) data within a volume segment with a magnetic resonance system, the MR data are repeatedly acquired with a sequence that includes radiating a first resonant RF pulse, radiating a second resonant RF pulse, applying a dephasing first gradient after the first resonant RF pulse and before the second resonant RF pulse, radiating a third resonant RF pulse after the second resonant RF pulse, applying a second gradient after the third RF pulse in order to refocus a stimulated echo of a magnetization component prepared by the first gradient, and read out MR data. At least one of the first gradient and/or the second gradient is/are different in a respective repetition of the sequence and an additional repetition of the sequence that directly follows the respective repetition. | 08-07-2014 |
20140218022 | MAGNETIC RESONANCE SYSTEM AND METHOD TO ACQUIRE MR DATA AND TO DETERMINE A B1 MAGNETIC FIELD - In a method and magnetic resonance (MR) system to acquire MR data within a volume segment, the MR data are repeatedly acquired with a sequence that which includes the following steps. A first resonant RF pulse is radiated and a second resonant RF pulse is radiated. A dephasing first gradient is applied after the first resonant RF pulse and before the second resonant RF pulse. A third resonant RF pulse is radiated after the second resonant RF pulse. A second gradient is applied after the third RF pulse in order to refocus a stimulated echo of a magnetization component prepared by the first gradient. MR data are read out, and a fourth resonant RF pulse is radiated after the readout of the MR data, to reduce the longitudinal magnetization. | 08-07-2014 |
20150070013 | Establishing B1-Maps - The embodiments relate to a B | 03-12-2015 |