3D Balanced EPI Magnetic Resonance Fingerprinting

• US 20160291107A1
• Filed: 04/01/2016
• Published: 10/06/2016
• Est. Priority Date: 04/02/2015
• Status: Active Grant

• Current Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Inventors: Rosen, Matthew S., Sarracanie, Mathieu, Cohen, Ouri
• Granted Patent: US 10,598,750 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 33/4835 of multiple slices
• CPC Class Codes: G01R 33/50 based on the determination of relaxation times , e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences
• CPC Class Codes: G01R 33/543 Control of the operation of the MR system, e.g. setting of acquisition parameters prior to or during MR data acquisition, dynamic shimming, use of one or more scout images for scan plane prescription G01R33/546 takes precedence
• CPC Class Codes: G01R 33/5614 using a fully balanced steady-state free precession [bSSFP] pulse sequence, e.g. trueFISP
• CPC Class Codes: G01R 33/5616 using gradient refocusing, e.g. EPI

Abstract

Provided is a system and method for performing a magnetic resonance fingerprinting imaging process. The process includes determining acquisition parameters including at least one of repetition time (TR) or flip angle (FA), selected to control one of a duration and a number of repetitions of for a pulse sequence that samples k-space in a Cartesian acquisition pattern by acquiring an echo train. The process also includes controlling a magnetic resonance imaging (MRI) system to perform the pulse sequence a plurality of times to acquire magnetic resonance fingerprinting (MRF) data corresponding to signals from the subject excited by the pulse sequence. The process also includes estimating quantitative tissue properties of the subject by comparing the MRF data to a database and reconstructing, from the MRF data, at least one image of the subject indicating the estimated quantitative tissue properties.

Claims

1. A method for acquiring magnetic resonance fingerprinting (MRF) data from a subject using a magnetic resonance imaging (MRI) system, the method including steps comprising:

a) selecting a pulse sequence to perform that samples k-space in a Cartesian acquisition pattern by acquiring an echo train;

b) determining acquisition parameters for the pulse sequence, including at least one of repetition time (TR) or flip angle (FA), selected to control one of a duration and a number of repetitions of the pulse sequence;

c) directing a magnetic resonance imaging (MRI) system to acquire 3-dimensional (3D) magnetic resonance fingerprinting (MRF) data from the subject by performing the pulse sequence;

d) directing the MRI system to repeat step c) using varied scan parameters to acquire sets of the 3D MRF data using differing scan parameters;

e) estimating quantitative tissue properties of the subject by comparing the sets of the 3D MRF data using differing scan parameters to a database; and

f) generate at least one image of the subject indicating the quantitative tissue properties.

2. The method of claim 1, wherein step d) includes using a variable FA, α

, that is varied according to the acquisition parameters for each repetition of step c) to acquire the sets of the 3D MRF data using differing scan parameters.

3. The method of claim 1, wherein step b) includes providing an initial, randomly generated seed vector of the acquisition parameters.

4. The method of claim 3, wherein the seed vector has a length, N, and is used to simulate a signal for a range, P, of quantitative parameters.

5. The method of claim 4, the quantitative parameters include at least one of T₁ values, T₂ values, proton density values, or off-resonance.

6. The method of claim 4, wherein the seed vector and simulated quantitative parameters are used to form an N×

P matrix, A.

7. The method of claim 6, wherein the matrix, A, is used to calculate a dot product matrix having off-diagonal elements indicating a quality of matching between different elements of the matrix, A.

8. The method of claim 7, wherein step b) includes performing an optimization process according to:

9. The method of claim 1, wherein the varied scan parameters include TR and FA.

10. The method of claim 1, wherein the pulse sequence includes a 3D balanced-echo planar imaging (b-EPI) pulse sequence.

11. The method of claim 10, wherein the pulse sequence includes balanced stead state free precession (b-SSFP) EPI pulse sequence.

12. The method of claim 1, wherein step c) includes averaging data acquired from a common echo train.

13. The method of claim 1, wherein the quantitative tissue properties include proton density, ρ

, T1, or T2.

14. A magnetic resonance imaging (MRI) system, comprising:

a magnet system configured to generate a static magnetic field about at least a volume of interest (VOI) of a subject arranged in the MRI system;

at least one gradient coil 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 a subject; and

a computer system programmed to;

determine acquisition parameters including at least one of repetition time (TR) or flip angle (FA), selected to control one of a duration and a number of repetitions of for a pulse sequence that samples k-space in a Cartesian acquisition pattern by acquiring an echo train;

control the at least one gradient coil and the RF system to perform the pulse sequence a plurality of times;

acquire magnetic resonance fingerprinting (MRF) data corresponding to signals from the subject excited by the pulse sequence;

estimate quantitative tissue properties of the subject by comparing the MRF data to a database; and

reconstruct, from the MRF data, at least one image of the subject indicating the estimated quantitative tissue properties.

15. The system of claim 14, wherein the static magnetic field is less than 10 mT.

16. The system of claim 14, wherein the computer system is further programmed to control the at least one gradient coil and the RF system to perform the pulse sequence a plurality of times includes using a variable FA, α

, that is varied according to the acquisition parameters for each repetition to acquire the of MRF data using differing scan parameters.

17. The system of claim 14, wherein the pulse sequence includes a 3D balanced-echo planar imaging (b-EPI) pulse sequence.

18. The method of claim 17, wherein the pulse sequence includes balanced stead state free precession (b-SSFP) EPI pulse sequence.

19. The method of claim 14, wherein the computer system is further programmed to utilize delays in the pulse sequence provided for magnetization recovery of successive phase encoding k-space lines for acquisition of multiple slices to acquire three-dimensional (3D) MRF data.

20. The method of claim 14, wherein the quantitative tissue properties include proton density, ρ

, T1, or T2.