Ge Precision Healthcare LLC

Hua Li

Lei Gao

Yongchuan Lai

Richard Scott Hinks

Ting Ting Zhang

Florian Wiesinger

Xuan Liu

Xiaoli Zhao

Jiabin Yao

Gaohong G Wu

Ty A Cashen

Kang Wang

Andreas Ebel

Zhenghui Zhang

Rolf Schulte

A system and a method for measuring eddy currents with long time constants includes initiating, via a processor, a calibration scan of a phantom utilizing a magnetic resonance imaging (MRI) scanner. The system and the method also include utilizing, via the processor, a train of gradient echo sequences to simultaneously generate and measure the eddy currents during the calibration scan. Both eddy current generation and measurement are completed within each gradient echo sequence of the train of gradient echo sequences. The system and the method further include acquiring, via the processor, k-space data from the train of gradient echo sequences. The system and the method still further include converting, via the processor, the k-space data to eddy current gradient fields. The system and the method even further include estimating, via the processor, the eddy currents as a function of time based on the eddy current gradient fields.

System and method for measuring eddy currents with long time constants using a pseudo-continuous acquisition

A method for correcting diffusion-weighted echo-planar imaging data (DW-EPI) includes obtaining a first reference scan with no diffusion gradients applied, a second reference scan with a diffusion gradient applied only along a frequency direction, a third reference scan with the diffusion gradient applied only along a phase direction, and a fourth reference scan with the diffusion gradient applied only along a slice direction acquired utilizing an MRI scanner, wherein the reference scans lack phase encoding. The method includes obtaining DW-EPI data acquired utilizing the MRI scanner, wherein the DW-EPI data includes phase errors due to oscillatory eddy currents causing time-varying Bshift. The method includes generating a phase correction factor based on the reference scans and correcting the phase errors due to the oscillatory eddy currents in the DW-EPI data independent of diffusion gradient direction utilizing the phase correction factor to generate corrected DW-EPI data.

System and method for oscillatory eddy current correction for diffusion-weighted echo-planar imaging

A method for generating an image of an object with a magnetic resonance imaging (MM) system is presented. The method includes first performing a calibration scan of the object. The calibration scan is performed with a zero echo time (ZTE) radial sampling scheme to obtain calibration k-spaces for surface coil elements and a body coil of the MRI system. The calibration scan is performed in such a manner that the endpoints of calibration k-space lines in each calibration k-space follow a spiral path. A plurality of calibration parameters are then obtained from the plurality of calibration k-spaces. A second scan of the object is then performed to acquire the MR image data. The image of the object is then generated based on the plurality of calibration parameters and the MR image data.

Silent calibration for magnetic resonance imaging

A magnetic resonance imaging system and method, and a computer-readable storage medium are provided. The magnetic resonance imaging method includes: acquiring a plurality of k-space data sets by using a plurality of imaging sequences, each imaging sequence comprising a pre-phase-dispersion gradient pulse and a plurality of phase encoding gradients applied after the pre-phase-dispersion gradient pulse, wherein the pre-phase-dispersion gradient pulses of the plurality of imaging sequences have a standard area difference therebetween when ordered according to area values; respectively reconstructing magnetic resonance images from the respective k-space data sets; and averaging amplitudes of the magnetic resonance images to generate a magnetic resonance image of an average amplitude.

Magnetic resonance imaging system and method, and computer-readable storage medium

A magnetic resonance (MR) imaging method of correcting phase errors is provided. The method includes applying, by an MR system, a pulse sequence to acquire the precorrection MR image. The method also includes acquiring, by the MR system, reference k-space data having a field of view (FOV) in a phase-encoding direction that is twice or more greater than an FOV of the precorrection MR image in the phase-encoding direction, wherein the reference k-space data and MR signals of the precorrection MR image are acquired with the same type of pulse sequences. The method further includes splitting the reference k-space data into first k-space data and second k-space data, generating a phase error map based on the first k-space data and the second k-space data, generating a phase-corrected image of the precorrection MR image based on the phase error map, and outputting the phase-corrected image.

Phase correction systems and methods of magnetic resonance images

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Sussex, WI, United States of America

Hua Li