Broad bandwidth magnetic resonance spectroscopy at high static (B0) magnetic field using polarization transfer

Patent metadata

Field	Value
Publication number	US-9529064-B2
Application number	US-201213984910-A
Country	US
Kind code	B2
Filing date	Jan 10, 2012
Priority date	Feb 15, 2011
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A magnetic resonance (MR) generating a static (BO) magnetic field of 5 Tesla or higher controller is configured to control an MR scanner to perform an MR sequence ( 14 ) including: performing an excitation/localization sub-sequence ( 30 ) on a subject disposed in the static (BO) magnetic field generated by the MR scanner to excite 1H polarization in a selected spatial region of the subject; performing 5 a polarization transfer sub-sequence ( 32 ) to transfer localized 1H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei; and performing a magnetic resonance spectroscopy (MRS) readout sub-sequence ( 40 ) to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject. The polarization transfer sub-sequence includes a pair of phase 10 distortion canceling trapezoidal 180° refocusing pulses ( 36, 37 ) operating on the selected species of non-proton nuclei.

First claim

The invention claimed is:

1. A method comprising:
performing, using an MR scanner and an MR controller comprising a digital processing device configured to control the MR scanner, a magnetic resonance (MR) sequence including:
performing an excitation/localization sub-sequence on a subject to excite 1 H polarization localized in a selected spatial region of the subject,
performing a polarization transfer sub-sequence to transfer localized 1 H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei wherein the polarization transfer sub-sequence includes a pair of phase distortion canceling 180° refocusing pulses operating on the selected species of non-proton nuclei, the pair of phase distortion canceling 180° refocusing pulses comprising trapezoidal refocusing pulses; and
performing a magnetic resonance spectroscopy (MRS) readout sub-sequence to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject.

2. The method of claim 1 , wherein the selected species of non-proton nuclei is 13 C.

3. The method of claim 1 , wherein the subject is an in vivo human or veterinary subject.

4. The method of claim 1 , wherein the excitation/localization sub-sequence includes spatial localization by image-selected in vivo spectroscopy (ISIS).

5. The method of claim 1 , wherein the polarization transfer sub-sequence employs distortionless enhancement of polarization transfer (DEPT).

6. The method of claim 1 , wherein the pair of phase distortion canceling 180° refocusing pulses operating on the selected species of non-proton nuclei comprise Offset Independent Trapezoid (OIT) adiabatic inversion pulses.

7. The method of claim 1 , wherein the magnetic resonance (MR) sequence is performed on the subject in a static (B0) magnetic field having a strength of 5 Tesla or higher.

8. The method of claim 1 , wherein the magnetic resonance (MR) sequence is performed on the subject in a static (B0) magnetic field having a strength of 7 Tesla or higher.

9. The method of claim 1 , wherein the magnetic resonance (MR) sequence further includes performing a decoupling sub-sequence applied concurrently with the readout sub-sequence to decouple 1 H polarization from polarization of the selected species of non-proton nuclei.

10. The method of claim 1 , further comprising:
generating at least one of (1) a magnetic resonance spectroscopy (MRS) spectrum and (2) a magnetic resonance spectroscopic imaging (MRSI) image from the acquired MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject; and
displaying the MRS spectrum or MRSI image.

11. A method comprising:
performing, using an MR scanner and an MR controller comprising a digital processing device configured to control the MR scanner, a magnetic resonance (MR) sequence including:
performing an excitation/localization sub-sequence on a subject to excite 1 H polarization localized in a selected spatial region of the subject,
performing a polarization transfer sub-sequence to transfer localized 1 H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei wherein the polarization transfer sub-sequence includes a pair of phase distortion canceling 180° refocusing pulses operating on the selected species of non-proton nuclei; and
performing a magnetic resonance spectroscopy (MRS) readout sub-sequence to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject;

wherein the pair of phase distortion canceling 180° refocusing pulses operating on the selected species of non-proton nuclei provides a constant flip angle for the selected species of non-proton nuclei over a band width of at least 10 kHz.

12. A method comprising:
performing, using an MR scanner and an MR controller comprising a digital processing device configured to control the MR scanner, a magnetic resonance (MR) sequence including:
performing an excitation/localization sub-sequence on a subject to excite 1 H polarization localized in a selected spatial region of the subject,
performing a polarization transfer sub-sequence to transfer localized 1 H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei wherein the polarization transfer sub-sequence includes a pair of phase distortion canceling 180° refocusing pulses operating on the selected species of non-proton nuclei; and
performing a magnetic resonance spectroscopy (MRS) readout sub-sequence to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject;

wherein the polarization transfer sub-sequence further includes a pair of phase distortion canceling 180° refocusing pulses operating on 1 H nuclei.

13. The method of claim 12 , wherein the pair of phase distortion canceling 180° refocusing pulses operating on 1 nuclei provides a constant flip angle for 1 H nuclei over a band width of at least 6 kHz.

14. The method of claim 12 , wherein the pair of phase distortion canceling 180° refocusing pulses operating on 1 H nuclei comprise trapezoidal refocusing pulses.

15. The method of claim 12 , wherein the pair of phase distortion canceling 180° refocusing pulses operating on 1 H nuclei comprise Offset Independent Trapezoid (OIT) adiabatic inversion pulses.

16. An apparatus comprising:
a magnetic resonance (MR) scanner generating a static (B0) magnetic field of 5 Tesla or higher; and
an MR controller configured to control the MR scanner to perform an MR sequence including:
performing an excitation/localization sub-sequence on a subject disposed in the static (B0) magnetic field generated by the MR scanner to excite 1 H polarization localized in a selected spatial region of the subject,
performing a polarization transfer sub-sequence to transfer localized 1 H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei, the polarization transfer sub-sequence including at least one trapezoidal refocusing pulse operating on the selected species of non-proton nuclei; and
performing a magnetic resonance spectroscopy (MRS) readout sub-sequence to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject.

17. The apparatus as set forth in claim 16 , wherein the MR scanner generates a static (B0) magnetic field of 7 Tesla or higher.

18. The apparatus as set forth in claim 16 , wherein the polarization transfer sub-sequence includes a pair of trapezoidal refocusing pulses operating on the selected species of non-proton nuclei.

19. The apparatus as set forth in claim 16 , wherein the polarization transfer sub-sequence includes a pair of trapezoidal adiabatic inversion pulses operating on the selected species of non-proton nuclei.

20. A non-transitory storage medium storing instructions executable by a processor to control a magnetic resonance (MR) scanner to perform an MR sequence, the method including:
performing an excitation/localization sub-sequence on a subject to excite 1 H polarization localized in a selected spatial region of the subject,
performing a polarization transfer sub-sequence to transfer localized 1 H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei wherein the polarization transfer sub-sequence includes at least one trapezoidal 180° refocusing pu

Assignees

• Yang Baolian
• Foxall David Leslie
• Koninklijke Philips Nv

Inventors

• Yang Baolian
• Foxall David Leslie

Classifications

• G01R33/4616

  using specific RF pulses or specific modulation schemes, e.g. stochastic excitation, adiabatic RF pulses, composite pulses, binomial pulses, Shinnar-le-Roux pulses, spectrally selective pulses not being used for spatial selection · CPC title

• G01R33/32 Primary

  Excitation or detection systems, e.g. using radio frequency signals · CPC title

• G01R33/483

  with selection of signals or spectra from particular regions of the volume, e.g. in vivo spectroscopy · CPC title

• G01R33/485

  based on chemical shift information {[CSI] or spectroscopic imaging, e.g. to acquire the spatial distributions of metabolites} · CPC title

• G01R33/4608 Primary

  RF excitation sequences for enhanced detection, e.g. NOE, polarisation transfer, selection of a coherence transfer pathway · CPC title