Methods and apparatuses for fast chemical shift magnetic resonance imaging

• US 20060094952A1
• Filed: 11/10/2005
• Published: 05/04/2006
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Ma, Jingfei, Bankson, James A., Stafford, R. Jason, Choi, Haesun
• Granted Patent: US 7,358,729 B2
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/4828 Resolving the MR signals of different chemical species, e.g. water-fat imaging
• CPC Class Codes: G01R 33/485 based on chemical shift information [CSI] or spectroscopic imaging, e.g. to acquire the spatial distributions of metabolites
• CPC Class Codes: G01R 33/5607 by reducing the NMR signal of a particular spin species, e.g. of a chemical species for fat suppression, or of a moving spin species for black-blood imaging
• CPC Class Codes: 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

Abstract

Systems and methods are described for chemical shift magnetic resonance imaging in the presence of multiple chemical species. A method includes obtaining a plurality of MRI data signals using a Dixon technique in combination with partially parallel imaging techniques and/or inversion recovery techniques, and processing the plurality of MRI data signals using a Dixon reconstruction technique to create a chemical specific shift image. An apparatus includes a MRI scanner for obtaining images, a controller configured to provide input to the scanner to acquire images using a Dixon technique in combination with partially parallel imaging techniques and/or inversion recovery techniques to produce a plurality of MRI data signals, and processing the plurality of MRI data signals using a Dixon reconstruction technique to create a chemical specific shift image, and an output device to display the resulting image.

Claims

1. A method for chemical shift imaging comprising:

obtaining a plurality of magnetic resonance imaging data signals using a Dixon technique combined, with an inversion recovery technique; and

processing the plurality of magnetic resonance imaging data signals using a Dixon reconstruction technique to create a chemical shift image.

2. The method of claim 1, the data signals comprising signals for a plurality of chemical species.

3. The method of claim 2, the plurality of chemical species comprising water, fat, and silicon.

4. The method of claim 1, the inversion recovery technique comprising a short tau inversion recovery technique.

5. The method of claim 1, further comprising selecting an inversion time appropriate for suppressing a chemical species based on the relaxation time constant of the chemical species.

6. The method of claim 1, the Dixon technique comprising a spin echo technique.

7. The method of claim 6, the spin echo technique comprising a fast spin echo technique.

8. The method of claim 1, the Dixon technique comprising a gradient echo technique.

9. The method of claim 1, the Dixon technique comprising a two-point Dixon technique.

10. The method of claim 1, the Dixon technique comprising a three-point Dixon technique.

11. The method of claim 1, the Dixon technique comprising a fast Dixon technique.

12. The method of claim 11, the fast Dixon technique further comprising:

generating an echo shifting gradient pulse on a readout axis in the presence of a primary and gradient magnetic field system;

generating a readout gradient pulse on the readout axis; and

detecting magnetic resonance echo signals resulting from the readout gradient.

13. The method of claim 12, further comprising generating a compensating gradient pulse on the readout axis.

14. The method of claim 13, the compensating gradient pulse having a polarity opposite a polarity of the echo shifting gradient pulse.

15. The method of claim 1, the Dixon reconstruction technique comprising a Dixon phase-correction scheme.

16. The method of claim 15, the Dixon phase-correction scheme comprising:

selecting an orientation vector parallel to a direction of local field inhomogeneity of the plurality of magnetic resonance imaging data signals; and

correcting phase errors of the plurality of magnetic resonance imaging data signals using the orientation vector.

17. The method of claim 1, the Dixon reconstruction technique comprising a sensitivity encoding reconstruction technique.

18. The method of claim 1, the step of obtaining the plurality of magnetic resonance imaging data signals using a Dixon technique combined with the inversion recovery technique suppresses a plurality of signals for one chemical species from the data signals.

19. The method of claim 18, the chemical species comprising fat.

20. The method of claim 1, the step of obtaining a plurality of magnetic resonance imaging data signals further comprising using a sensitivity encoding technique.

21. The method of claim 1, wherein images of two different chemical species are produced.

22. The method of claim 21, wherein the two chemical species are water and silicone.

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37. An apparatus to produce a chemical shift image comprising:

a magnetic resonance imaging scanner for obtaining images;

a controller configured to provide input to the scanner to acquire images using a Dixon technique combined with a short tau inversion recovery technique to produce a plurality of magnetic resonance imaging data signals, and processing the plurality of magnetic resonance imaging data signals using a Dixon reconstruction technique to create a chemical shift image; and

an output device to display the resulting image.

38. The apparatus of claim 37, the Dixon technique comprising a fast spin echo technique.

39. The apparatus of claim 37, the Dixon technique comprising a fast Dixon technique.

40. The apparatus of claim 38, the fast Dixon technique further comprising:

generating an echo shifting gradient pulse on a readout axis in the presence of a primary and gradient magnetic field system;

generating a readout gradient pulse on the readout axis; and

detecting magnetic resonance echo signals resulting from the readout gradient.

41. The apparatus of claim 40, the controller further generating a compensating gradient pulse on the readout axis.

42. The apparatus of claim 41, the compensating gradient pulse comprising a polarity opposite a polarity of the echo shifting gradient pulse.

43. The apparatus of claim 37, the Dixon reconstruction technique including a Dixon phase-correction scheme.

44. The apparatus of claim 43, wherein the Dixon phase-correction scheme comprises:

selecting an orientation vector parallel to a direction of local field inhomogeneity of the plurality of magnetic resonance imaging data signals; and

correcting phase errors of the plurality of magnetic resonance imaging data signals using the orientation vector.

45. The apparatus of claim 37, the controller using the Dixon reconstruction technique including a sensitivity encoding reconstruction technique that preserves the relative phase information for each Dixon image.

46. The apparatus of claim 37, the controller using the short tau inversion recovery technique to suppress a plurality of fat signals from the plurality of magnetic resonance imaging data signals.

47. The apparatus of claim 37, the controller being further configured to calculate a water-only image and a silicone-only image.

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