System and methods for fast multi-contrast magnetic resonance imaging

Patent metadata

Field	Value
Publication number	US-11266324-B2
Application number	US-201515305515-A
Country	US
Kind code	B2
Filing date	Apr 24, 2015
Priority date	Apr 24, 2014
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

Systems and methods for performing fast multi-contrast magnetic resonance imaging (“MRI”) are provided. In general, data are acquired from both multiple echo times (“TEs”) and at multiple effective inversion times (“TIs”). Following the application of a magnetization preparation radio frequency (“RF”) pulse, a plurality of different multi-echo acquisitions are performed, thereby acquiring data from multiple different TEs during different portions of the longitudinal magnetization recovery curve. Data acquisition in these inner encoding loops (i.e., during each multi-echo acquisition) can be accelerated to efficiently provide for the acquisition of multiple contrasts in the time normally required to acquire a single contrast.

First claim

The invention claimed is:

1. A method for producing a series of images that depict different image contrasts using a magnetic resonance imaging (MRI) system, steps of the method comprising:
(a) directing the MM system to acquire multi-contrast data from a subject by performing a pulse sequence that includes:
(i) applying a magnetization preparation radio frequency (RF) pulse to create magnetization-prepared longitudinal magnetization;
(ii) performing a multi-echo acquisition to acquire data from multiple different echo times during a period of time in which the magnetization-prepared longitudinal magnetization is recovering along a continuously increasing recovery curve to equilibrium;
(iii) repeating step (ii) a plurality of times to acquire data from the multiple different echo times during different periods of time in which the magnetization-prepared longitudinal magnetization is recovering to equilibrium to achieve multiple different effective inversion times;

wherein the data acquired in steps (ii) and (iii) collectively form the multi-contrast data; and
(b) reconstructing a series of images that depict different image contrasts from the multi-contrast data.

2. The method as recited in claim 1 , wherein the multi-echo acquisition performed in step (ii) implements an accelerated multi-echo data acquisition scheme in which data are undersampled along at least one direction ink-space.

3. The method as recited in claim 2 , wherein the accelerated multi-echo acquisition is accelerated by undersampling along a direction in a plane of k-space.

4. The method as recited in claim 3 , wherein the accelerated multi-echo acquisition undersamples k-space along a partition-encoding direction.

5. The method as recited in claim 4 , further comprising acquiring calibration data during step (a), such that the calibration data and multi-contrast data have matching image contrasts.

6. The method as recited in claim 4 , further comprising directing the MM system to acquire calibration data from the subject using a different pulse sequence than the pulse sequence performed in step (a).

7. The method as recited in claim 1 , wherein the magnetization preparation RF pulse is an inversion recovery RF pulse.

8. The method as recited in claim 1 , further comprising generating a segmented image of the subject based on the reconstructed series of images that depict different image contrasts.

9. The method as recited in claim 1 , further comprising producing a parametric map that depicts a magnetic resonance parameter based on the reconstructed series of images that depict different image contrasts.

10. The method as recited in claim 9 , wherein the parametric map is produced by fitting the reconstructed series of images that depict different image contrasts to a magnetic resonance signal model.

11. The method as recited in claim 9 , wherein the magnetic resonance parameter is at least one of proton density (PD), longitudinal relaxation time (T1), and apparent transverse relaxation time (T2*).

12. The method as recited in claim 9 , further comprising producing a synthesized image based on the parametric map and the reconstructed series of images that depict different image contrasts, the synthesized image depicting an image contrast not contained in the reconstructed series of images that depict different image contrasts.

13. The method as recited in claim 9 , further comprising generating a segmented image of the subject based on the parametric map and the reconstructed series of images that depict different image contrasts.

14. A magnetic resonance imaging (MRI) system, comprising:
a magnet system configured to generate a static magnetic field about at least a portion of a subject arranged in the MRI system;
a gradient coil system configured to establish at least one magnetic gradient field with respect to the static magnetic field;
a radio frequency (RF) system configured to deliver excitation pulses to the subject and acquire data from the subject;
a computer system programmed to:
control the RF system to applying a magnetization preparation RF pulse to create magnetization-prepared longitudinal magnetization;
control the gradient coil system and the RF system to acquire accelerated imaging data while the magnetization-prepared longitudinal magnetization is recovering along a continuously increasing recovery curve to equilibrium by skipping a subset of phase-encoding or partition-encoding steps;
control the gradient coil system and the RF system to repeatedly acquire the accelerated imaging data for each phase encoding, or partition encoding, to acquire a multi-contrast image dataset; and
reconstruct a series of images that depict different image contrasts from the multi-contrast dataset, wherein the multi-contrast dataset includes data that spans both multiple echo times (“TEs”) and multiple effective inversion times (“TIs”).

15. The system as recited in claim 14 , wherein the computer system is configured to estimate data missing in the accelerated imaging data using parallel imaging methods.

16. The system as recited in claim 14 , wherein the computer system is further configured to control the gradient coil system and the RF system to acquire calibration data, such that the calibration data and multi-contrast data have matching image contrasts.

17. The system as recited in claim 16 , wherein the computer system is further configured to use the calibration data in a parallel imaging reconstruction process to estimate data missing from the accelerated imaging data due to skipping the subset of phase encoding or partition-encoding steps.

18. The system as recited in claim 14 , wherein the magnetization preparation RF pulse is an inversion recovery RF pulse.

19. The system as recited in claim 14 , wherein the computer system is configured to produce a parametric map that depicts a magnetic resonance parameter based on the reconstructed series of images that depict different image contrasts.

Assignees

• Massachusetts Gen Hospital

Inventors

• Polimeni Jonathan
• Van Der Kouwe Andre
• Tisdall Matthew
• Fischl Bruce

Classifications

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/5611

  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) · CPC title

• G01R33/50

  based on the determination of relaxation times {, e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences} · 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

• G01R33/58

  Calibration of imaging systems, e.g. using test probes {, Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material} · CPC title