Magnetic resonance imaging system and method

Patent metadata

Field	Value
Publication number	US-11519990-B1
Application number	US-202217588443-A
Country	US
Kind code	B1
Filing date	Jan 31, 2022
Priority date	Jan 31, 2022
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A method for producing an image of an object with a MRI system includes providing a Shear In Readout Encoding Imaging (SIREN) gradient pulse in a phase gradient signal waveform. The phase gradient signal waveform is applied to a phase gradient coil of the MRI system. The application of the SIREN gradient pulse provides a SIREN k-space of the object which has SIREN k-space lines with a shear angle. A MR image space data from the SIREN k-space is then obtained by applying a reconstruction technique. Finally, the image of the object is generated by transforming SIREN MR image space data into regular image space data using a decoding algorithm based on the shear angle.

First claim

The invention claimed is:

1. A method for producing an image of an object with a magnetic resonance imaging (MRI) system, the method comprising:
providing a Shear In Readout Encoding Imaging (SIREN) gradient pulse in a phase gradient signal waveform applied to a phase gradient coil of the MRI system;
obtaining a SIREN k-space of the object, wherein k-space lines of the SIREN k-space have a shear angle;
obtaining MR image space data from the SIREN k-space; and
generating the image of the object by transforming SIREN MR image space data into regular image space data using a decoding algorithm based on the shear angle.

2. The method of claim 1 further comprising applying a readout gradient signal waveform to a readout gradient coil of the MRI system, wherein the readout gradient signal waveform includes a dephase pulse and a main readout pulse.

3. The method of claim 2 , wherein the phase gradient signal waveform includes a first phase encoding gradient pulse and a second phase encoding gradient pulse and wherein the SIREN gradient pulse is applied between the first phase encoding gradient pulse and the second phase encoding gradient pulse.

4. The method of claim 2 , wherein an amplitude of the SIREN gradient pulse is determined based on the shear angle and the amplitude of the main readout pulse.

5. The method of claim 2 , wherein the SIREN gradient pulse is applied simultaneously at the time of the main readout pulse.

6. The method of claim 1 further comprising providing a SIREN dephaser gradient pulse before the SIREN gradient pulse in the phase gradient signal waveform applied to the phase gradient coil of the MRI system.

7. The method of claim 6 , wherein an area under the SIREN dephaser gradient pulse is half that of an area under the SIREN gradient pulse.

8. The method of claim 1 , wherein the shear angle is determined based on a medical image application, a field of view or combinations thereof.

9. The method of claim 1 , wherein obtaining MR image space data from the SIREN k-space comprises applying an inverse Fourier transform to the SIREN k-space.

10. The method of claim 1 , wherein the decoding algorithm shifts the x-axis coordinates of SIREN MR image space by a factor y*tan θ, where y is the corresponding y-axis coordinate of the SIREN MR image space and θ is the shear angle.

11. The method of claim 1 , wherein when the image of the object has a cutoff area, the method includes using a larger field of view in the y-axis of the SIREN MR image space data.

12. The method of claim 1 , wherein when the image of the object is a 3D image, the method includes providing an additional SIREN gradient pulse in a slice selection gradient signal waveform of the MRI system.

13. A magnetic resonance imaging (MRI) system, comprising:
a magnet configured to generate a polarizing magnetic field about at least a portion of an object arranged in the MRI system;
a gradient coil assembly including a readout gradient coil, a phase gradient coil, a slice selection gradient coil configured to apply at least one gradient field to the polarizing magnetic field;
a radio frequency (RF) system configured to apply an RF field to the object and to receive magnetic resonance signals from the object;
a processing system programmed to:
provide a Shear In Readout Encoding Imaging (SIREN) gradient pulse in a phase gradient signal waveform, wherein the phase gradient signal waveform is applied to the phase gradient coil;
obtain a SIREN k-space of the object, wherein k-space lines of the SIREN k-space have a shear angle;
obtain MR image space data from the SIREN k-space; and
generate the image of the object by transforming SIREN MR image space data into regular image space data using a decoding algorithm based on the shear angle.

14. The MRI system of claim 13 , wherein the processing system is programmed to apply a readout gradient signal waveform to a readout gradient coil of the MRI system, wherein the readout gradient signal waveform includes a dephase pulse and a main readout pulse.

15. The MRI system of claim 14 , wherein the phase gradient signal waveform includes a first phase encoding gradient pulse and a second phase encoding gradient pulse and wherein the SIREN gradient pulse is applied between the first phase encoding gradient pulse and the second phase encoding gradient pulse.

16. The MRI system of claim 14 , wherein an amplitude of the SIREN gradient pulse is determined based on the shear angle and the amplitude of the main readout pulse.

17. The MRI system of claim 13 , wherein the processing system is programmed to obtain MR image space data from the SIREN k-space by applying an inverse Fourier transform to the SIREN k-space.

18. The MRI system of claim 13 , wherein the decoding algorithm shifts the x-axis coordinates of SIREN MR image space by a factor y*tan θ, where y is the corresponding y-axis coordinate of the SIREN MR image space and θ is the shear angle.

19. The MRI system of claim 13 , wherein when the image of the object is a 3D image, the processing system is programmed to provide an additional SIREN gradient pulse in a slice selection gradient signal waveform of the MRI system.

20. A method for producing an image of an object with a magnetic resonance imaging (MRI) system, the method comprising:
providing a Shear In Readout Encoding Imaging (SIREN) gradient pulse in a phase gradient signal waveform applied to a phase gradient coil of the MRI system;
obtaining a SIREN k-space data of the object, wherein k-space lines of the SIREN k-space data have a shear angle;
transforming SIREN k-space data of the object into regular domain k-space data using a decoding algorithm based on the shear angle; and
generating the image of the object from the regular domain k-space data.

Assignees

• Ge Prec Healthcare Llc

Inventors

• Shen Hao

Classifications

• G01R33/56545

  caused by finite or discrete sampling, e.g. Gibbs ringing, truncation artefacts, phase aliasing artefacts · CPC title

• G01R33/482 Primary

  using a Cartesian trajectory · CPC title

• G01R33/5608 Primary

  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) · CPC title

• G01R33/56 Primary

  Image enhancement or correction, e.g. subtraction or averaging techniques {, e.g. improvement of signal-to-noise ratio and resolution} · CPC title

• G01R33/5602

  by filtering or weighting based on different relaxation times within the sample, e.g. T1 weighting using an inversion pulse · CPC title