Granted Patent B2

US 12,186,104 · App. 17/639,276 · Granted Jan 7, 2025

Inventor: Phillip Zhe Sun (Atlanta, GA)

Assignee: Emory University

A61B5/7203G01R33/445G01R33/483G01R33/5605G01R33/5608G06V10/25G06V10/98

Abstract

Claims (74)

1. A method for correcting MR data comprising:

providing an inhomogeneity field/response map of a region of interest;

wherein the inhomogeneity field/response map is a high-resolution B 0 inhomogeneity field/response map;

providing MR data of the region of interest;

wherein the MR data is CEST Z-spectrum image(s)/spectrum or MT Z-spectrum image(s)/spectrum, each voxel of the MR data corresponds to a plurality of subvoxels of the B 0 inhomogeneity field/response map;

registering the inhomogeneity field/response map and the MR data;

constructing a subvoxel discrete B 0 response from the registered inhomogeneity field/response map;

constructing a voxel discrete Z-spectrum;

determining an intravoxel inhomogeneity correction coefficient for each voxel of at least one subregion of the region of the interest using the inhomogeneity field/response map;

wherein the determining the intravoxel inhomogeneity correction co-efficient includes deconvolving the subvoxel discrete B 0 response from the voxel discrete Z-spectrum; and

correcting each voxel of the MR data of the region of interest using the intravoxel inhomogeneity correction coefficient.

2. The method according to claim 1 , wherein the subvoxel discrete B 0 response is represented by a subvoxel discrete B 0 point spread function (PSF).

3. A method for correcting MR data comprising:

providing an inhomogeneity field/response map of a region of interest;

wherein the inhomogeneity field/response map is a high-resolution B 0 inhomogeneity field/response map;

providing MR data of the region of interest;

wherein the MR data is MR spectroscopy (MRS)/MR spectroscopic imaging (MRSI) image(s)/spectrum; and

wherein each voxel of the MRS/MRSI image(s)/spectrum corresponds to a plurality of subvoxels of the B 0 inhomogeneity field/response map; and

registering the inhomogeneity field/response map and the MR data;

constructing a subvoxel discrete B 0 response from the registered B 0 inhomogeneity field/response map, and

constructing the MRS/MRSI image(s)/spectrum using an interval that is equal to the subvoxel discrete B 0 response;

determining an intravoxel inhomogeneity correction coefficient for each voxel of at least one subregion of the region of the interest using the inhomogeneity field/response map;

wherein the determining the intravoxel inhomogeneity correction co-efficient includes deconvolving the subvoxel discrete B 0 response from the voxel discrete MRS/MRSI spectrum; and

correcting each voxel of the MR data of the region of interest using the intravoxel inhomogeneity correction coefficient.

4. The method according to claim 3 , wherein:

the constructing the MRS/MRSI image(s)/spectrum includes constructing MR real signals, MR imaginary signals, complex signal, MRS signal with a phase adjustment, and/or a combination thereof; and

the deconvolving includes deconvolving the MR real signals, the MR imaginary signals, the complex signal, the MRS signal with the phase adjustment, and/or a combination thereof.

5. The method according to claim 4 , wherein the deconvolving the MR real signals and the MR imaginary signals are performed independently, and the method further comprising:

integrating the MR real signals and the MR imaginary signals after the deconvolving to reconstruct complex MRS signal.

6. The method according to claim 3 , wherein the subvoxel discrete B 0 response is represented by a subvoxel discrete B 0 point spread function.

7. A method for correcting MR data:

providing an inhomogeneity field/response map of a region of interest;

wherein the inhomogeneity field/response map is a high-resolution B 0 inhomogeneity field/response map;

providing MR data of the region of interest;

wherein the MR data is CEST non Z-spectrum image(s)/spectrum or MT non Z-spectrum image(s)/spectrum;

registering the inhomogeneity field/response map and the MR data;

determining a voxel inhomogeneity correction coefficient for each voxel of at least one subregion of the region of the interest using the registered B 0 inhomogeneity field/response map and the MR data; and

correcting each voxel of the MR data of the region of interest using the voxel inhomogeneity correction coefficient;

wherein the corrected data is corrected using the intravoxel inhomogeneity correction coefficient.

8. The method according to claim 7 , wherein the determining the voxel inhomogeneity correction coefficient includes determining a regression of B 0 inhomogeneity and measured CEST effect of one or more subregions of the region of interest using the registered B 0 inhomogeneity field/response map and the MR data, the one or more subregions of the region of interest having a homogenous CEST signal intensity.

9. A method for correcting MR data comprising:

providing an inhomogeneity field/response map of a region of interest;

providing MR data of the region of interest;

determining an intravoxel inhomogeneity correction coefficient for each voxel of at least one subregion of the region of the interest using the inhomogeneity field/response map; and

correcting each voxel of the MR image(s)/spectrum of the region of interest using the intravoxel inhomogeneity correction coefficient;

determining a quasi-steady state signal for each voxel for each saturation offset using the corrected voxel, T1 map, B1, and scan parameters, the scan parameters including saturation time; and

standardizing each corrected voxel using the quasi-steady state signal for each saturation offset.

10. The method according to claim 9 , wherein the determining the quasi-steady state spectrum for each voxel includes:

determining a steady state spinlock relaxation rate using at least the saturation time; and

determining the quasi-steady state signal for each voxel for each saturation offset based on the steady state spinlock relaxation rate.

11. The method according to claim 9 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel for each offset.

12. A method for correcting MR data comprising

providing a B 0 inhomogeneity field map/response of a region of interest;

providing MR data of the region of interest, the MR data corresponding to CEST data or MT data;

registering the B 0 inhomogeneity field/response map and the MR data;

determining a voxel inhomogeneity correction coefficient for each voxel of at least one subregion of the region of the interest using the registered B 0 inhomogeneity field/response map;

correcting each voxel of the MR data of the region of interest using the voxel inhomogeneity correction coefficient;

determining a quasi-steady state signal for each voxel for each saturation offset using the corrected voxel, T1 map, B1, and scan parameters, the scan parameters including saturation time; and

standardizing each corrected voxel using the quasi-steady state signal for each saturation offset.

13. The method according to claim 12 , wherein the determining the quasi-steady state spectrum for each voxel includes:

determining a steady state spinlock relaxation rate using-using at least the saturation time; and

determining the quasi-steady state signal for each voxel for each saturation offset based on the steady state spinlock relaxation rate.

14. The method according to claim 12 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel.

15. The method according to claim 13 , the CEST data is non Z-spectrum data and the MT data is non Z spectrum data.

16. The method according to claim 1 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel for each offset.

17. The method according to claim 3 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel for each offset.

18. The method according to claim 7 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel for each offset.

19. The method according to claim 13 , further comprising:

determining one or more quantitative measurements using each standardized and/or corrected voxel for each offset.

Continuity (2)

References Cited (30)