# US 2025/0085371 A1 · Gradient Delay Time Correction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0085371 A1 - Document ID: US20250085371A1 - Status: Published application - Kind: A1 - Application number: 18/882,910 - Filed: 2024-09-12 - Published: 2025-03-13 - Earliest claimed: 2023-09-13 - Assignees: Siemens Healthineers AG - Applicants: Siemens Healthineers AG - Inventors: Christian Meixner; Simon Bauer; Max Müller; Dominik Paul; Marcel Dominik Nickel; Michael Köhler - Web page: https://patentgrep.com/patent/US20250085371A1 ## CPC - G01R 33/4826: {in three dimensions} - G01R 33/5611: {Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by Fourier encoding of the overlaps using the temporal dimension [UNFOLD], k-t-broad-use linear acquisition speed-up technique [k-t-BLAST], k-t-SENSE (structural details of arrays of sub-coils G01R33/3415)} - G01R 33/5608: {Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels (image data processing or generation, in general G06T)} - G01R 33/56518: {due to eddy currents, e.g. caused by switching of the gradient magnetic field} - G01R 33/56572: {caused by a distortion of a gradient magnetic field, e.g. non-linearity of a gradient magnetic field (G01R33/56509, G01R33/56518, G01R33/56536 take precedence)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A computer-implemented method for gradient delay time correction of MR data using an MR device, wherein the magnetic resonance data is recorded using a three-dimensional recording technique with linear recording trajectories which are oriented in different readout directions of a readout plane that is perpendicular to a partition direction. The method includes: in a calibration measurement using the magnetic resonance device, recording calibration data which describes readout-direction-dependent shifts, caused by delay effects, of measurement points in the k-space; determining correction data by evaluating the calibration data; correcting the MR data based on the correction data in order to compensate for the delay effects, wherein the calibration data, which covers a coverage region in partition direction is recorded in a resolved manner, and the correction data is determined and applied in a manner that is dependent on partition direction. ## Claims ### Claim 1 A computer-implemented method for gradient delay time correction of magnetic resonance data using a magnetic resonance device, wherein the magnetic resonance data is recorded using a three-dimensional recording technique with linear recording trajectories which are oriented in different readout directions of a readout plane that is perpendicular to a partition direction, the computer-implemented method comprising: in a calibration measurement using the magnetic resonance device, recording calibration data that describes readout-direction-dependent shifts, caused by delay effects, of measurement points in k-space; determining correction data by evaluating the calibration data; and correcting the magnetic resonance data based on the correction data in order to compensate for the delay effects, wherein the calibration data, which covers a coverage region in a partition direction is recorded in a resolved manner in partition direction, and the correction data is determined and applied in a manner that is dependent on partition direction. ### Claim 2 (depends on 1) The computer-implemented method as claimed in claim 1, further comprising: sampling radial spokes using the three-dimensional recording technique and/or recording calibration data for different partitions in partition direction. ### Claim 3 (depends on 1) The computer-implemented method as claimed in claim 1, further comprising: recording the calibration data for at least two calibration readout directions such that a k-space section of the respective readout direction is traversed in contra-oriented calibration recording trajectories; and evaluating the calibration data of each readout direction to determine a k-space shift, which is dependent on the partition in partition direction in a position space of the calibration recording trajectories in opposing directions for each partition covered by the calibration data in partition direction, wherein the k-space shifts form the correction data. ### Claim 4 (depends on 3) The computer-implemented method as claimed in claim 3, further comprising: for determining k-space shifts for further readout directions of the readout plane, which do not correspond to one of the calibration readout directions, geometrically combining the k-space shifts of the calibration readout directions according to a mathematical correlation. ### Claim 5 (depends on 3) The computer-implemented method as claimed in claim 3, wherein for determining the correction data for each calibration readout direction, the calibration data of both contra-oriented calibration recording trajectories in partition direction is Fourier-transformed for distribution over partitions in the position space, whereupon for each partition: cross-correlated calibration data profiles for the calibration recording trajectories are cross-correlated in order to determine a shift in the position space, and the k-space shift associated with the greatest correlation is determined. ### Claim 6 (depends on 1) The computer-implemented method as claimed in claim 1, wherein for correcting the delay effects in the magnetic resonance data, Fourier-transforming the magnetic resonance data for assignment to partitions in partition direction; determining a correction k-space shift from the correction data for each readout direction and partition that is used for recording the calibration data; and shifting the magnetic resonance data, which has been Fourier-transformed in partition direction, according to the respective correction k-space shifts. ### Claim 7 (depends on 1) The computer-implemented method as claimed in claim 1, wherein a plurality of receive channels are used during the measurement of the calibration data and the magnetic resonance data. ### Claim 8 (depends on 7) The computer-implemented method as claimed in claim 7, wherein correction values are limited using a lowest permissible minimum value and/or a highest permissible maximum value. ### Claim 9 (depends on 8) The computer-implemented method as claimed in claim 8, further comprising, during receive channel-specific evaluation of the calibration data for determining the correction data: determining receive channel-specific evaluation values corresponding to correction values; and determining a minimum value and/or a maximum value using statistical processing of the evaluation values. ### Claim 10 (depends on 7) The computer-implemented method as claimed in claim 7, further comprising: using an identification condition, identifying and ignoring receive channels that have measurement results that deviate excessively when determining the correction data. ### Claim 11 (depends on 1) The computer-implemented method as claimed in claim 1, wherein the calibration data is recorded using a whole-body coil of the magnetic resonance device and the magnetic resonance data is recorded using a local coil arrangement comprising a plurality of receive channels. ### Claim 12 (depends on 1) The computer-implemented method as claimed in claim 1, wherein when evaluating calibration data for determining correction data, masking of the calibration data is performed in a position space in order to exclude regions that are not covered by a recorded examination object and/or peripheral parts of the examination object. ### Claim 13 (depends on 1) A magnetic resonance device, comprising: a control device that is designed to carry out the computer-implemented method as claimed in claim 1. ### Claim 14 (depends on 1) A non-transitory electronically readable data medium storing a computer program which, when executed on a control device of a magnetic resonance device, causes the control device to perform the computer-implemented method as claimed in claim 1.