Methods, systems and apparatuses for rapid segmented, accelerated, and simultaneous multi-slice echo planar imaging

Patent metadata

Field	Value
Publication number	US-9588208-B2
Application number	US-201414271754-A
Country	US
Kind code	B2
Filing date	May 7, 2014
Priority date	May 7, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A method for accelerated segmented magnetic resonance (MR) image data acquisition includes using a plurality of RF pulses to excite one or more slices of an anatomical area of interest according to a predetermined slice acceleration factor. Next, a collapsed image comprising the slices is acquired using a consecutive segment acquisition process. Then, a parallel image reconstruction method is applied to the collapsed image to separate the collapsed image into a plurality of slice images.

First claim

We claim:

1. A method for accelerated segmented magnetic resonance (MR) image data acquisition, the method comprising:
using a plurality of Radio Frequency (RF) pulses to excite one or more slices of an anatomical area of interest according to a predetermined slice acceleration factor;
acquiring a collapsed image of the one or more slices in response to the plurality of RF pulses, wherein each of the one or more slices is individually acquired using a consecutive segment acquisition process; and
applying a parallel image reconstruction method to the collapsed image to separate the collapsed image into a plurality of slice images.

2. The method of claim 1 , wherein the predetermined slice acceleration factor is greater than 1 and each of the plurality of RF pulses is a multiband RF pulse operable to simultaneously excite the one or more slices of the anatomical area of interest.

3. The method of claim 1 , wherein the consecutive segment acquisition process applies a varying flip angle sequence across a plurality of consecutive segments of k-space line data representative of a respective slice.

4. The method of claim 3 , wherein the varying flip angle sequence is a progression of flip angles that maximizes magnetization of a region of the anatomical area of interest corresponding to the respective slice.

5. The method of claim 3 , wherein the varying flip angle sequence comprises a predetermined low flip angle repeated for each segment included in the respective slice.

6. The method of claim 5 , further comprising:
applying one or more dummy pulses prior to acquiring each of the one or more slices.

7. The method of claim 1 , wherein the consecutive segment acquisition process is integrated with an in-plane accelerated acquisition process applied to the anatomical area of interest.

8. The method of claim 1 , wherein the parallel image reconstruction method is Slice GRAPPA.

9. The method of claim 8 , further comprising:
performing a reference scan of the anatomical area of interest to acquire a plurality of reference slices using the consecutive segment acquisition process; and
using the plurality of reference slices to calibrate the parallel image reconstruction method such that echo-spacing of the plurality of reference slices is matched to accelerated image data corresponding to the collapsed image.

10. The method of claim 9 , further comprising:
performing a plurality of additional reference scans of the anatomical area of interest to acquire a plurality of additional reference slices using the consecutive segment acquisition process; and
averaging the plurality of reference slices and the plurality of additional reference scans together to yield a plurality of averaged reference slices,
wherein the parallel image reconstruction method is calibrated using the plurality of averaged reference slices.

11. The method of claim 9 , further comprising:
following the reference scan, performing an additional reference scan to acquire one segment of the anatomical area of interest using a high flip angle pulse; and
using the one segment of the anatomical area of interest to calibrate a Slice GRAPPA in-plane kernel used in the parallel image reconstruction method.

12. The method of claim 1 , further comprising:
applying an encoding technique to control an aliasing pattern of the collapsed image.

13. A method for accelerated segmented magnetic resonance (MR) image data acquisition, the method comprising:
applying a plurality of RF pulses to excite a plurality of slices of an anatomical area of interest according to a predetermined slice acceleration factor;
performing a slice acquisition process for each respective slice included in the plurality of slices to acquire a collapsed image, the slice acquisition process comprising:
creating a varying flip angle sequence to be applied across a plurality of consecutive segments of k-space line data representative of the respective slice, and
acquiring each segment of k-space line data included in the respective slice using the varying flip angle sequence; and

applying a parallel image reconstruction method to the collapsed image to separate the collapsed image into a plurality of slice images.

14. The method of claim 13 , wherein the predetermined slice acceleration factor is greater than 1 and each of the plurality of RF pulses is a multiband RF pulse operable to simultaneously excite the plurality of slices of the anatomical area of interest.

15. The method of claim 13 , further comprising:
wherein the varying flip angle sequence is a progression of flip angles that maximizes magnetization of a region of the anatomical area of interest located at the respective slice.

16. The method of claim 13 , wherein the varying flip angle sequence comprises a predetermined low flip angle repeated for each segment of k-space line data included in the respective slice.

17. The method of claim 16 , further comprising:
applying one or more dummy pulses prior to the slice acquisition process for each respective slice.

18. The method of claim 13 , wherein the parallel image reconstruction method is Slice GRAPPA.

19. The method of claim 18 , further comprising:
performing a reference scan of the anatomical area of interest to acquire a plurality of reference slices using the slice acquisition process;
using the plurality of reference slices to calibrate the parallel image reconstruction method such that echo-spacing of the plurality of reference slices is matched to accelerated image data corresponding to the collapsed image.

20. The method of claim 13 , further comprising:
applying an encoding technique to control an aliasing pattern of the collapsed image.

21. The method of claim 20 , wherein the encoding technique comprises a Blipped-Controlled Aliasing in Parallel Imaging technique.

22. A system for performing accelerated segmented magnetic resonance (MR) image data acquisition, the system comprising:
a Radio Frequency (RF) generator configured to use a plurality of RF coils to:
simultaneously excite a plurality of slices of an anatomical area of interest with a plurality of multi-band RF pulses, and
acquire a collapsed image comprising a plurality of acquired slices in response to the plurality of multi-band RF pulses, wherein each of the plurality of acquired slices is individually acquired using a consecutive segment acquisition process; and

an image data processor configured to apply a parallel image reconstruction method to the collapsed image to separate the collapsed image into a plurality of slice images.

Assignees

• Massachusetts Gen Hospital
• Siemens Medical Solutions Usa Inc
• Nat Inst Of Health (Nih) U S Dept Of Health And Human Services (Dhhs) U S Government Nih Div Of Extr
• Siemens Healthcare Gmbh

Inventors

• Polimeni Jonathan Rizzo
• Bhat Himanshu
• Heberlein Keith Aaron
• Setsompop Kawin
• Witzel Thomas
• Cauley Stephen Farman

Classifications

• G01R33/4835

  of multiple slices · CPC title

• G01R33/546

  Interface between the MR system and the user, e.g. for controlling the operation of the MR system or for the design of pulse sequences · CPC title

• G01R33/5616

  using gradient refocusing, e.g. EPI · CPC title

• G01R33/5611 Primary

  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) · CPC title

• G01R33/482

  using a Cartesian trajectory · CPC title