Patent application number | Description | Published |
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 |
20120139539 | METHOD FOR GENERATING A PULSE SEQUENCE TO ACQUIRE MAGNETIC RESONANCE DATA, AND OPERATING METHOD AND MAGNETIC RESONANCE SYSTEM EMPLOYING THE GENERATED PULSE SEQUENCE - In a method for generating a pulse sequence for operating a magnetic resonance (MR) system for acquiring data from an examination subject having an interfering object in the patient's body, the bandwidths of at least two of the RF (radio-frequency) pulses in the pulse sequence are matched such that the matched RF pulses respectively excite a congruent slice when they are radiated into an examination subject under the effect of a slice selection gradient of identical amplitude. The matching of the RF pulses in the manner ensures so that the respective slices excited by the at least two RF pulses are subject to the same nonlinearities and inhomogeneities, and therefore the same spatial distortions, and so that signal losses due to inconsistent excitations of the two pulses are avoided. The image data that can be acquired with the pulse sequence are therefore optimized. | 06-07-2012 |
20130076356 | MAGNETIC RESONANCE IMAGING METHOD AND APPARATUS TO CORRECT DISTORTIONS DUE TO INHOMOGENEITIES OF THE BASIC MAGNETIC FIELD - In a magnetic resonance method and system to correct spatial shifts in MR data, at least two measurement data sets are acquired, the additional measurement data set or sets being acquired while switching an additional gradient relative to acquisition of the first measurement data set. For respective corresponding measurement points of the measurement data sets, a phase difference is initially determined from the first measurement data set and at least one additional measurement data set acquired with the additional gradient, with a spatial shift of the measurement points of the first measurement data set being determined from the spatial shift. The magnitude values of the initially measured measurement points are distributed to their correct spatial position corresponding to the determined spatial shifts, so a corrected image data set is created. | 03-28-2013 |
20130200893 | Determination of a Measuring Sequence for a Magnetic Resonance System - A method and a measuring-sequence-determining device for determining a measuring sequence for a magnetic resonance system based on at least one intra-repetition-interval time parameter are provided. During the determination of the measuring sequence in a gradient-optimization method, gradient-pulse parameters of the measuring sequence are automatically optimized to reduce at least one gradient-pulse-parameter maximum value. As a boundary condition in the gradient-optimization method, the intra-repetition-interval time parameter is kept constant at least within a specified tolerance value. | 08-08-2013 |
20130230223 | METHOD TO GENERATE MAGNETIC RESONANCE SLICE EXPOSURES - In a method processor and magnetic resonance (MR) system to generate MR slice exposures of an examination subject, measurement data for a stack of measurement slices through the examination subject are initially acquired using a series of slice measurement sequences. The series of slice measurement sequences is designed to allow a separation of a first material from a second material that has a defined chemical shift relative to said first material, and the position of a measurement slice with measurement data for the first material is spatially shifted relative to the position of a measurement slice with measurement data for the second material. Combination slice exposures are then formed by combining measurement data of the first material from at least a first slice measurement sequence with measurement data of the second material from at least one second slice measurement sequence, such that the image data of the first and second materials are spatially arranged with precise positioning relative to one another, at least within a predetermined degree of tolerance in the combination slice exposures. | 09-05-2013 |
20140111200 | METHOD AND APPARATUS FOR OPTIMIZATION OF A PULSE SEQUENCE FOR A MAGNETIC RESONANCE SYSTEM - A method and a pulse sequence optimization device to optimize a pulse sequence for a magnetic resonance system, wherein the pulse sequence includes at least one refocusing pulse, one slice selection gradient pulse, and one gradient spoiler pulse. The pulse duration of the refocusing pulse is shortened, and the pulse duration of the slice selection gradient pulse is adapted to the shortened pulse duration of the refocusing pulse. The amplitude of the slice selection gradient pulse is increased so that the same slice thickness is selected as before the shortening of the pulse duration of the refocusing pulse. The pulse shape of the gradient spoiler pulse is adapted without changing a total spoiler moment, and an optimally shortened pulse duration of the refocusing pulse is achieved when, with the adaptation of the pulse shape of the gradient spoiler pulse, the maximum amplitude of the gradient spoiler pulse equals the amplitude of the slice selection gradient pulse, and an edge steepness of the gradient spoiler pulse is minimized. | 04-24-2014 |
20140300357 | METHOD AND MAGNETIC RESONANCE SYSTEM TO DETERMINE A RESONANCE FREQUENCY DEVIATION - In a first method and magnetic resonance apparatus to determine a resonance frequency deviation given an excitation of a slice of a volume segment within an examination subject, by a slice selection gradient is activated along one direction, an RF excitation pulse is irradiated in order to excite nuclear spins in the slice, a readout gradient is activated along the direction of the slice selection gradient, and MR data are read out while the readout gradient is activated. Image points within an MR image reconstructed using the MR data are identified, that exhibit a signal intensity that is greater than a predetermined threshold, in order to determine one of the image points that has a maximum separation in the direction between this image point and the slice. The resonance frequency deviation is determined depending on the amplitude of the slice selection gradient, the amplitude of the readout gradient and the maximum separation. The slice selection gradient and the readout gradient have opposite polarity. | 10-09-2014 |
20150108975 | METHOD AND APPARATUS FOR OPTIMIZATION OF A PULSE SEQUENCE FOR A MAGNETIC RESONANCE SYSTEM - In a method and a pulse sequence optimization device to optimize a pulse sequence for a magnetic resonance system, wherein pulse sequence includes at least one refocusing pulse, a readout gradient pulse temporally situated after the refocusing pulse, and at least one readout spoiler pulse, the pulse duration of the readout gradient pulse is shortened while keeping the readout gradient moment constant, and the pulse shape of the readout spoiler pulse is adapted without changing a total spoiler moment. An optimally shortened pulse duration of the readout gradient pulse is achieved when, with the adaptation of the pulse shape of the readout spoiler pulse, a maximum amplitude of the readout spoiler pulse equals to the amplitude of the readout gradient pulse, and an edge steepness of the readout spoiler pulse is minimized. | 04-23-2015 |