Magnetic resonance fingerprinting (MRF) with efficient acquisition schemes

Patent metadata

Field	Value
Publication number	US-10898089-B2
Application number	US-201514690511-A
Country	US
Kind code	B2
Filing date	Apr 20, 2015
Priority date	Apr 22, 2014
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

Example apparatus and methods improve magnetic resonance fingerprinting (MRF) by performing MRF with optimized spatial encoding, parallel imaging, and utilization of field inhomogeneities. Multi-echo radial trajectories and spiral trajectories may acquire data according to sampling schemes based on models of charge distribution on a sphere. Non-uniform sampling schemes may account for differences in detector coil performance. Field inhomogeneities provide spatial information that enhances the spatial separation of an MRF signal and facilitates unaliasing pixels. The field inhomogeneity may be manipulated. An MRF pulse sequence may include frequency selective RF pulses that are determined by the field inhomogeneities. Inhomogeneities combined with selective RF pulses result in higher acquisition efficiency.

First claim

What is claimed is:

1. A method, comprising:
acquiring information concerning a B 0 inhomogeneity in a magnetic field associated with a magnetic resonance imaging (MRI) apparatus, where the MRI apparatus will apply a magnetic resonance fingerprinting (MRF) pulse sequence to an object located in the magnetic field;
selecting an acquisition trajectory based, at least in part, on the inhomogeneity for an acquisition of nuclear magnetic resonance (NMR) signals that will be generated by the object in response to the MRF pulse sequence;
selecting a frequency selective radio frequency (RF) pulse to include in the MRF pulse sequence;
controlling the MRI apparatus to apply the MRF pulse sequence including the frequency selective RF pulse to the object, and
controlling the MRI apparatus to acquire the resulting NMR signals according to the acquisition trajectory.

2. The method of claim 1 , where the RF pulse is selected based, at least in part, on the inhomogeneity or the acquisition trajectory.

3. The method of claim 2 , comprising creating the inhomogeneity.

4. The method of claim 3 , where creating the inhomogeneity includes varying a size, shape, direction, or number of axes associated with the inhomogeneity.

5. The method of claim 3 , where creating the inhomogeneity includes controlling a field gradient produced by the MRI apparatus, a quadrapolar field produced by the MRI apparatus, or a shim coil manipulated by the MRI apparatus.

6. The method of claim 3 , comprising controlling the inhomogeneity to be constant throughout the MRF pulse sequence.

7. The method of claim 3 , comprising controlling the inhomogeneity to vary during the MRF pulse sequence.

8. The method of claim 3 , comprising controlling the inhomogeneity to vary per acquisition period of the MRF pulse sequence.

9. The method of claim 3 , comprising controlling the inhomogeneity to be less than 2π per voxel.

10. The method of claim 4 , comprising selecting a timing for a parameter of the MRF pulse sequence.

11. The method of claim 10 , where the timing is selected based, at least in part, on the inhomogeneity.

12. The method of claim 4 , comprising selecting a flip angle for the MRF pulse sequence.

13. The method of claim 12 , where the flip angle is selected based, at least in part, on the inhomogeneity.

14. The method of claim 1 , where the acquisition trajectory is a multi-echo radial trajectory or a spiral trajectory.

15. The method of claim 1 , where the acquisition trajectory is a uniform trajectory.

16. The method of claim 15 , where the uniform trajectory is based, at least in part, on a model of charge distribution on a sphere.

17. The method of claim 16 , where the model is a Golden Sphere model or a Charge Repulsion model.

18. The method of claim 14 , where the trajectory is a non-uniform trajectory.

19. The method of claim 18 , where the amount of sampling performed in an area by the non-uniform trajectory is inversely proportional to the detector coil performance in the area.

20. The method of claim 1 , comprising selecting a number N of frequency selective RF pulses to include in the MRF pulse sequence, where N is determined by the receive bandwidth of the MRI apparatus, N being an integer.

21. The method of claim 1 , comprising selecting a number N of frequency selective RF pulses to include in the MRF pulse sequence, where N is determined by the cross correlation between different excitation areas associated with the N RF pulses, N being an integer.

22. The method of claim 1 , where the pulse sequence is designed to produce a signal evolution from which two or more MR parameters may be quantified in a single acquisition, where the signal evolution is described by:

SE
=

∑

s
=
1

N
s

⁢

∏

i
=
1

N
A

⁢

∑

j
=
1

N
RF

⁢

R
i

⁡

(
α
)

⁢

R

RF
ij

⁡

(

α
,
ϕ

)

⁢

R
⁡

(
G
)

⁢

E
i

⁡

(

T
⁢

⁢
1

,

T
⁢

⁢
2

,
D

)

⁢

M
0

or

SE
=

∑

s
=

Assignees

• Univ Case Western Reserve

Inventors

• Gulani Vikas
• Griswold Mark
• Ma Dan
• Yang Alice

Classifications

• A61B5/055

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

• A61B5/742

  using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339) · CPC title

• G01R33/56366

  Perfusion imaging · CPC title

• G01R33/4818

  MR characterised by data acquisition along a specific k-space trajectory or by the temporal order of k-space coverage, e.g. centric or segmented coverage of k-space · 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