Arterial spin labeling (ASL) with magnetic resonance fingerprinting (MRF)

Patent metadata

Field	Value
Publication number	US-10136824-B2
Application number	US-201514690524-A
Country	US
Kind code	B2
Filing date	Apr 20, 2015
Priority date	Apr 22, 2014
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Example apparatus and methods perform magnetic resonance fingerprinting (MRF) for arterial spin labeling (ASL) based parameter quantification. ASL with MRF produces a nuclear magnetic resonance signal time course from which simultaneous quantification of ASL perfusion-related parameters can be achieved. The parameters may include cerebral blood flow, transit time, T1, or other parameters. The quantification uses values from a dictionary of signal time courses that were generated or augmented using Bloch simulation, knowledge of the sequence, or previous observations. The dictionary may account for inflow or outflow of labeled spins and may model arterial input. An ASL-MRF pulse sequence may differ from conventional pulse sequences. For example, an ASL-MRF pulse sequence may include non-uniform control pulses, non-uniform label pulses, non-uniform post labeling delay time, non-uniform background suppression pulses, non-uniform acquisition repetition time, or non-uniform acquisition flip angle.

First claim

What is claimed is:

1. A method for performing arterial spin labeling (ASL) with magnetic resonance fingerprinting (MRF), comprising:
selecting an ASL-MRF pulse sequence to apply to an object, where the ASL-MRF pulse sequence includes a labeling pulse and a control pulse;
controlling a magnetic resonance (MR) apparatus to apply the ASL-MRF pulse sequence to the object;
acquiring a nuclear magnetic resonance (NMR) signal evolution from the object, where the NMR signal evolution depends, at least in part, on a property of the arterial spins in the object;
selecting an entry in an MRF dictionary associated with the NMR signal evolution, and
simultaneously quantifying two or more properties of the arterial spins in the object based, at least in part, on the entry.

2. The method of claim 1 , where the two or more properties of the arterial spins include cerebral blood flow (CBF), transit time, or T1 relaxation.

3. The method of claim 1 , where the ASL-MRF pulse sequence has a pseudo-continuous ASL (PCASL) labeling scheme.

4. The method of claim 3 , where the PCASL labeling scheme is described by a function L(t), where L(t) is positive during a labeling pulse, L(t) is negative during a control pulse, and L(t)=0 during post label delay and data acquisition.

5. The method of claim 3 , where applying the ASL-MRF pulse sequence causes arterial spins to be delivered to a portion of the object over time according to a variable arterial input function.

6. The method of claim 1 , where the ASL-MRF pulse sequence includes alternating labeling pulses and control pulses.

7. The method of claim 1 , where the ASL-MRF pulse sequence includes a non-uniform arrangement of non-uniform background suppression pulses, non-uniform acquisition periods, or non-uniform acquisition flip angles (FA).

8. The method of claim 7 , where the ASL-MRF pulse sequence produces non-uniform post-labeling decay in the NMR signal evolution acquired from the object.

9. The method of claim 1 , where the ASL-MRF pulse sequence includes a non-uniform arrangement of control pulses and label pulses.

10. The method of claim 9 , where the ASL-MRF pulse sequence includes control pulses with varying duration or label pulses with varying tagging duration.

11. The method of claim 1 , comprising populating the MRF dictionary with signal evolutions that describe inflow or outflow of labeled spins according to:

d
⁢

⁢
M

d
⁢

⁢
t

=

M
0

-
M

T
1

+

fM
a

⁡

(
t
)

-

f
λ

⁢
M

where M is the magnetization in brain tissue,
M 0 is the default or equilibrium magnetization,
T 1 is the T1 value for tissue,
M a (t) is the magnetization of labeled arterial blood,
f is perfusion,
λ is a blood volume fraction associated with how much of a voxel is filled with blood,
Δt is the transit time of blood,
k(t−Δt) is a function to capture arterial dispersion, and
L(t) is the labeling function that indicates the occurrence of inversion pulses.

12. The method of claim 11 , comprising populating the MRF dictionary with signal evolutions that model arterial input according to:
M a ( t )= M 0 (1−2αϵ −Δt/T 1,a )* k ( t−Δt ), if L ( t )=1

M a ( t )= M 0 (1−ϵ −Δt/T 1,a )* k ( t−Δt ), if L ( t )≠1

where M is the magnetization in brain tissue,
M 0 is the default or equilibrium magnetization,
T 1 and T 1,a are the T 1 values for tissue and blood,
M a (t) is the magnetization of labeled arterial blood,
f is perfusion,
α is an inversion imperfection factor,
Δt is the transit time of blood,
k(t−Δt) is a function to capture arterial dispersion, and
L(t) is the labeling function that indicates the occurrence of inversion pulses.

13. The method of claim 1 , comprising populating the MRF dictionary with signal evolutions described by:

SE
=

∑

s
=
1

N
s

⁢

⁢

∏

i
=
1

N
A

⁢

⁢

∑

j
=
1

N
RF

⁢

⁢

R
i

⁡

(
α
)

⁢

R

RF
ij

Assignees

• Univ Case Western Reserve

Inventors

• Hernandez-Garcia Luis
• Griswold Mark
• Ma Dan
• Gulani Vikas
• Wright Katherine L
• Jiang Yun

Classifications

• A61B5/055

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

• A61B5/0263 Primary

  using NMR · 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

• A61B1/00

  Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes (examination of body cavities or body tracts using ultrasonic, sonic or infrasonic waves A61B8/12; endoscopic instruments for taking cell samples or for biopsy A61B10/04); Illuminating arrangements therefor (for the eyes A61B3/00) · 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