General Electric Company

Ge Medical Systems Global Technology Company, LLC

Ge Precision Healthcare LLC

General Electric Corporation Gmbh

Ge Medical Technology Services, Inc.

Richard Scott Hinks

Kevin Franklin King

Bruce David Collick

Bryan James Mock

Frederick Joseph Frigo

Jason Andrew Polzin

Dan Xu

Michael J Radziun

Scott Thomas Mansell

John Edward Lorbiecki

Gaohong G Wu

Sheila Srinivasan Washburn

Lei Gao

Matthew A Bernstein

Robert Steven Stormont

Graeme Colin McKinnon

Cherik T Bulkes

Darren Lee Hallman

Jingfei Ma

Kevin Matthew Koch

Yongchuan Lai

Robert Marc Lebel

Xuan Liu

Xiaoli Zhao

David E Dean

Patrick L Le Roux

David Thomas Gering

Shaorong Chang

Anton Max Linz

Jiabin Yao

Saban Kurucay

Jian Zhang

Dewain Anthony Purgill

Hua Li

Quan Zhu

Moran Wei

Andreas Ebel

Robert A Kraft

Juan Gao

Donald Elroy Kosak

Patrick L LeRoux

Atsushi Mark Takahashi

Tejaswini Shubhachint

David Glenn Lee

John E Lorbiecki, Sr

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

Systems and methods for suppressing Nyquist ghost for diffusion weighted magnetic resonance imaging are disclosed. An exemplary method includes acquiring multiple k-space data sets using multiple sets of diffusion weighted imaging pulse sequences, reconstructing a magnetic resonance image from each of the multiple k-space data sets respectively, and averaging magnitudes of the magnetic resonance images to generate an average magnitude magnetic resonance image.

Systems and methods for suppressing Nyquist ghost for diffusion weighted magnetic resonance imaging

Methods and systems are provided for hybrid slice encoding. In one embodiment, a method for magnetic resonance imaging comprises, during a scan with a pulse sequence, sampling k-space linearly for a predetermined number of echoes, and sampling k-space centrically for remaining echoes of the pulse sequence. In this way, blurriness along the slice direction may be reduced for 3D fast spin echo imaging.

Systems and methods for hybrid slice encoding in three-dimensional magnetic resonance imaging

Various methods and systems are provided for ghost artifact reduction in magnetic resonance imaging (MRI). In one embodiment, a method for an MRI system comprises acquiring a non-phase-encoded reference dataset, calculating phase corrections for spatial orders higher than first order from the non-phase-encoded reference dataset, acquiring a phase-encoded k-space dataset, correcting the phase-encoded k-space dataset with the phase corrections, and reconstructing an image from the corrected phase-encoded k-space dataset. In this way, ghost artifacts caused by phase errors during EPI may be substantially reduced, thereby improving image quality especially when imaging with a large field of view.

Method and systems for reducing artifacts in magnetic resonance imaging

A system and method is disclosed for eliminating localized fluctuation artifacts caused by fat signal contamination in MR images, the system includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images, and a computer programmed to apply a spectral-spatial fat saturation pulse, apply a slice selection gradient pulse, acquire imaging data of an imaging slice of interest, and generate an image.

System and method for reducing localized signal fluctuation

An apparatus and method include a computer programmed to implement a scan sequence configured to elicit scan data, wherein the scan sequence comprises an echo planar imaging (EPI) sequence configured to elicit the image data and to acquire the scan data. The computer is also programmed to manipulate the scan data to determine a first plurality of phase errors in the image data responsible for a Nyquist ghost, wherein the manipulated scan data is free of navigator echo data, remove the first plurality of phase errors from the image data, and reconstruct an image based on the image data having the first plurality of phase errors removed therefrom.

System and method of image artifact reduction using self-navigated real-time phase correction in echo planar imaging

Coil sensitivity of a receive coil to a gradient null location is measured and, from the measurements, a coil calibration value is determined and used to modify the MR data acquired with that receive coil to reduce the adverse effects of gradient nulling on MR images. Coil sensitivity values are determined for each coil of a coil array and the data for each coil is respectively weighted. An image that is substantially free of gradient null artifacts or ghosting is then reconstructed from the weighted data.

Method and system of MR imaging with reduced FSE cusp artifacts

The present invention includes a technique for use with magnetic resonance imaging that includes the application of a non-linear, higher-order gradient field in the presence of a moving object to be scanned. MR data is acquired as the object moves through the non-linear gradient field. Resulting images are contiguous and do not require the patching together of data in either k-space or image space and result in an image with expanded FOV in a longitudinal direction of the moving object.

Spatial encoding MR data of a moving subject using a higher-order gradient field

A technique for reconstructing a corrected MR image from MR images distorted by foreign object induced magnetic fields includes locating a foreign object in a subject and defining a localized area of a field of view about the foreign object where a magnetic field distortion adversely affects a first magnetic distortion correction technique. The first magnetic distortion correction technique is applied to the field of view other than in the localized area. A second magnetic distortion correction technique is applied to the localized area and the results of the application of the first and second magnetic distortion correction techniques are combined. An image is reconstructed based on the results of the application of the first and second magnetic distortion correction techniques.

Method and apparatus for correcting distortion in MR images caused by metallic implants

The present invention provides an apparatus and method of phase correction whereby changes in phase characteristics are measured during data acquisition and, accordingly, phase correction parameters that are applied during image reconstruction are updated in real-time. This adaptive and dynamic phase correction reduces variability in image fidelity during the course of long MR scans, such as EPI scans, and provides consistent artifact reduction during the course of an MR scan.

Method and apparatus of echo planar imaging with real-time determination of phase correction coefficients

A pulse sequence is defined to acquire calibration MR data used to characterize on-axis and cross-axis eddy currents resulting from gradient pulses used to spatially encode MR data. The amplitudes and time constants of those eddy currents can then be measured and used to guide calibration of an MRI system to reduce image artifacts.

Method and apparatus of directly measuring cross-axis eddy currents for MR scanner calibration

A nearest neighbor phase correction technique is implemented to reduce image artifacts due to phase errors in data acquired in an EPI scan. Image quality for EPI applications, such as DWI, DTI, and fMRI, is improved.

Method and system for image artifact reduction using nearest-neighbor phase correction for echo planar imaging

A method and system of MR imaging where variable readout gradient filtering (VRGF) is carried out after MR data acquired during gradient field transitions has been phase-corrected. Thus, phase errors can be removed prior to VRGF re-sampling of the MR data. As such, image artifacts due to phase errors can be reduced, improving image fidelity and reducing ghosting especially for poorly calibrated systems.

Method and system of MR imaging with variable readout gradient filtering

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Waukesha, WI, United States of America

Richard Scott Hinks