Mario Zeller has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: Automatically determining a correction factor for producing MR images includes outputting a first readout gradient along a readout dimension, reading out a first MR signal from a subject during the output of the first readout gradient, and specifying a second readout gradient having a theoretically identical gradient moment to the first readout gradient. A temporal waveform that differs from a temporal waveform of the first readout gradient is specified for the second readout gradient. The second readout gradient is output along the readout dimension. A second MR signal is read out from the subject during the output of the second readout gradient. A first extent of a representation of the subject is determined based on the first MR signal. A second extent of a representation of the subject is determined based on the second MR signal. A correction factor is obtained from a ratio between the first and second extents.
Abstract: In a method for creating a pulse sequence for controlling a magnetic resonance tomography apparatus as part of a CAIPIRINHA readout method for generating magnetic resonance image data of an examination object, two or more readout gradients and encoding gradients are used, wherein a readout gradient is positioned on a gradient axis and an encoding gradient is positioned on another gradient axis so as to occur simultaneously with the readout gradient. The encoding gradient has a periodic waveform. This positioning is repeated at different times in the pulse sequence, with the sampling density of a readout gradient being varied during a readout process, and/or the amplitude of the encoding gradients and/or of the readout gradients being varied for different readout processes.
Abstract: In a magnetic resonance method and apparatus for generating diffusion-weighted image data, at least two recordings are implemented in which raw data are acquired at raw data points of a raw data memory weighted with a b-value. The raw data memory has a first subregion and a second subregion, the first subregion being more than half of the total raw data points of the raw data memory. In each of the at least two recordings of the first subregion, full sampling takes place, and the second subregion is differently undersampled in the respective recordings. The raw data are combined and reconstructed into image data weighted with the b-value.
Abstract: In a magnetic resonance slice multiplexing method and apparatus, measurements are repeated with additional phase amounts being applied, wherein in each repetition, the additionally applied phase amounts are changed such that at least a central k-space region is fully sampled in the course of the repeated acquisitions. A calibration dataset, which is used in reconstructing image data for the simultaneously excited slices from the acquired measurement data, is determined from the measurement data that have been fully acquired in the central k-space region. The calibration dataset is updated in further measurements.
Abstract: In a method and apparatus for parallel recording of a magnetic resonance dataset with a number of reception coils, wherein the measurement data acquired by each coil are a predetermined part of a complete set of k-space data, an excitation pulse applied, followed by a refocusing pulse. The resulting echo signal of an image dataset is acquired while a first read gradient activated. A gradient in the phase direction is designed to be activated in order to acquire additional echo signal while an additional readout gradient is activated. The gradient in the phase direction is designed so that the additional echo signal contains k-space data that supplements the predetermined part of the k-space data.
Abstract: A storage medium, a magnetic resonance apparatus, and a method for obtaining a correction factor to balance a mismatch between gradient moments are disclosed herein. The method includes providing a magnetic resonance raw dataset, the generation of which includes acquiring the k-space of the magnetic resonance raw dataset in several partial measurements, wherein in each partial measurement, several k-space lines are at least partially sampled by setting a given set of acquisition parameters, applying at least one radio frequency excitation pulse, applying a first gradient in a predetermined direction, applying a second gradient in the predetermined direction, and reading out the magnetic resonance signals.
Abstract: In a method and apparatus for recording a magnetic resonance (MR) data set with MR signals from at least two slices, a first radio-frequency (RF) pulse is radiated in at least one first slice, a second RF pulse is radiated in at least one second slice, and readout of at least one first and at least one second MR signal takes place. The flip angle of the second RF pulse is smaller than the flip angle of the first RF pulse.
Abstract: A method for the simultaneous recording of magnetic resonance data relating to an examination subject from at least two different slices by a magnetic resonance sequence, wherein an excitation period of the magnetic resonance sequence that includes at least one sub-section that acts on only one of the slices, and that contains at least one high frequency pulse is used, wherein, to correct the main magnetic field inhomogeneities of the first order, for each slice affected by a sub-section, a correction parameter that modifies the gradient pulses that are to be emitted is determined, taking into account at least one main magnetic field map that describes the spatial distribution of the main magnetic field and a slice position of the affected slice and is applied in the emission of gradient pulses for the respective slice in the sub-section.
Abstract: Techniques are disclosed for acquiring magnetic resonance data of an object with a magnetic resonance imaging apparatus. A slice group is imaged whose slices define a contiguous imaging volume and which contains a first number of slices. In a number of concatenations, the magnetic resonance data for subgroups of the slices, each containing a respective second number of slices depending on the first number of concatenations, are acquired, and shimming is performed to increase field homogeneity in the imaging volume. To define the subgroups, the imaging volume is subdivided into at least two disjoint contiguous sub-volumes, and at least two subgroups are defined for each sub-volume, each subgroup only containing non-adjacent slices in the sub-volume. During acquisition of the magnetic resonance data of each subgroup, shimming is at least restricted to the respective sub-volume.
February 21, 2020
August 27, 2020
Siemens Healthcare GmbH
Dominik Paul, Flavio Carinci, Wilhelm Horger, Mario Zeller
Abstract: In a method for operating an MRI device, image data is acquired using a spin echo sequence with an additional readout per pulse train for acquiring correction data. By comparing subsequent correction data of later pulse trains to reference data acquired during a first pulse train of the sequence a difference indicating a parameter shift is determined. A corresponding compensation is then automatically determined in dependence on the difference and is applied to a set of predetermined parameters for at least a respective next pulse train and/or to the image data acquired in at least a respective next pulse train of the sequence.
Abstract: Medical examinations, such as e.g. MRT recordings, are to be able to be better planned. To this end, in accordance with the disclosure, it is proposed that a physiological parameter of the patient be acquired before the medical examination. Subsequently there is an automated establishment of the time schedule of the medical examination as a function of the physiological parameter of the patient acquired.
Abstract: In a magnetic resonance (MR) apparatus and an operating method therefor, MR data are acquired from a patient using an MR sequence wherein, after at least one excitation pulse, multiple refocusing pulses are radiated during a readout period. The respective strengths of the refocusing pulses proceed according to a first flip-angle variation over time that is defined so as to minimize the SAR of the patient. A multislice imaging technique is used for simultaneous excitation and readout of at least two slices of a slice group of the patient, and flip-angle variations, which differ from the first variation, are selected in order to further reduce the SAR of the patient, compared with the use of identical flip-angle variations.
Abstract: In a method and apparatus for creating MR images of an examination volume, MR reference data of the examination volume are determined, and a local weighting matrix is determined using the MR reference data in order to extract MR data of the examination volume from MR signals measured in accelerated fashion with the local weighting matrix. Motion of the examination volume is determined while the MR signals measured in accelerated fashion from the examination volume are detected, whereby, if an adaptation of the reconstruction process is required when taking into consideration the determined motion, this proceeds by recalculation of the local weighting matrix taking into consideration the determined motion for correction of the determined motion, and application of the recalculated weighting matrix during the creation of the MR images which are calculated on the basis of the MR signals measured in accelerated fashion.
Abstract: Techniques are described for generating an MR image of an object using a multi spin-echo based imaging sequence with a plurality of k space segments using a preparation pulse. The technique included acquiring a first k-space dataset of the object using a first echo time and a first delay after the preparation pulse before the several spin-echoes are acquired. The technique further includes acquiring a second k space dataset of the object using a second echo time and a second delay after the preparation pulse, with at least one of the second echo time and the second delay time being different from the corresponding first echo time and the first delay time, generating a combined k space, and generating the MR image based on the combined k space dataset.
January 23, 2020
July 23, 2020
Siemens Healthcare GmbH
Flavio Carinci, Dominik Paul, Mario Zeller
Abstract: In a method and magnetic resonance (MR) apparatus for avoiding artifacts in scan data recorded by execution of a spin-echo sequence, an excitation pulse is radiated, at least one refocusing pulse is radiated, and at least one echo signal is read out. Following the radiation of the excitation pulse and before the readout of the at least one echo signal, at least two artifact-avoidance gradients with different amplitudes are activated, wherein the moments of the artifact-avoidance gradients balance each other.
Abstract: A storage medium, a magnetic resonance apparatus, and a method for obtaining an operating parameter of a magnetic resonance apparatus are disclosed herein. The method includes generating of at least one echo train, wherein the generation of an echo train includes: setting a given set of parameters; applying at least one radio frequency excitation pulse; and applying a dephasing gradient in readout direction; and reading out the echo train having at least two echo signals, wherein a readout gradient is applied while reading out the echo signals. The method further includes acquiring at least two echo signals, wherein the set of parameters differs in at least one parameter being used for different echo signals; processing the echo signals line by line to projections; and obtaining the operating parameter using the projections.
Abstract: In a method for controlling a magnetic resonance tomography system for a Magnetic Resonance Fingerprinting (MRF) measurement: a dictionary group including at least two dictionaries is provided/created, each of the at least two dictionaries containing a multiplicity of different intensity profiles with a specific sampling scheme; a preliminary recording of magnetic resonance tomography (MRT) measurements is created; a sampling scheme is determined/defined based on the preliminary recording; a dictionary is selected from the at least two dictionaries of the dictionary group based on the preliminary recording; and an MRF measurement is performed using the defined sampling scheme and an MRF evaluation based on the selected dictionary.
Abstract: In a method and apparatus for creating magnetic resonance data of at least two simultaneously manipulated, non-overlapping slices of an examination object by a parallel acquisition technique, reference data are acquired such that, between acquisition of slice scan data of a slice scan data set in which the scan data of all simultaneously manipulated slices are incorporated in an overlaid manner, and its associated reference data, no slice scan data of a different slice scan data set are acquired. A high level of robustness with respect to movements of the examination object is thereby achieved.
Abstract: In a method and apparatus for recording a magnetic resonance data record in a capture region of an examination object, the capture region being composed of multiple slices, an imaging technique is implemented that uses reference data in the reconstruction of magnetic resonance images, wherein, for all the slices, at least two partial data records are recorded with respectively different contrasts. For thus purpose, a first partial data record is recorded without a preparation pulse and a second partial data record is recorded with a preparation pulse, in particular an inversion pulse. The reference data for at least one first slice for the first partial data record are recorded during a waiting time after the preparation pulse for at least one other, second slice, from which reference data relating to the second partial data record are to be recorded.
Abstract: In a method for detecting MR signals of an object in an MR scanner, in which the MR signals of the object are detected with receiving channels at the same time using a parallel imaging technique, where the MR signals are spin-echoes generated with a spin-echo based imaging sequence, a first magnetic field gradient (MFG) is applied in a slice selection direction (SSD) while applying an RF excitation pulse of the spin echo based imaging sequence, the first MFG having a first polarity during the application of the RF excitation pulse, a second MFG is applied in the SSD while applying at least a first RF refocusing pulse of the spin echo based imaging sequence, the second magnetic field gradient has a second polarity opposite to the first polarity, and the MR signals of the spin echo are detected to generate an MR image based on the detected MR signals.
December 13, 2019
June 18, 2020
Siemens Healthcare GmbH
Flavio Carinci, Dominik Paul, Mario Zeller