Method and system for susceptibility weighted magnetic resonance imaging

Patent metadata

Field	Value
Publication number	US-2018024216-A1
Application number	US-201615547557-A
Country	US
Kind code	A1
Filing date	Jan 29, 2016
Priority date	Feb 3, 2015
Publication date	Jan 25, 2018
Grant date	—

Abstract

Method for susceptibility weighted magnetic resonance imaging of vasculature, the method comprising the following steps: —acquiring multi-echo data containing a time-of-flight signal in at least the first echo (S 1 ); —identifying voxels belonging to arteries from the data (S 2 ); and —generating corresponding information on artery presence (S 3 ); The invention further relates to a corresponding system ( 10 ) for susceptibility weighted magnetic resonance imaging of vasculature.

First claim

1 . A method for susceptibility weighted magnetic resonance imaging of vasculature, the method comprising:
acquiring multi-echo data containing a time-of-flight signal in at least the first echo; identifying voxels belonging to arteries from the data; and generating corresponding information on artery presence; wherein the method further comprises an echo combination step or an echo combination step in combination with a phase masking step; and wherein said information on artery presence is used to put emphasis on an artery appearance during said echo combination and/or to prevent an inclusion of voxels belonging to arteries in the phase masking step.

2 . The method according to claim 1 , wherein an arterial image AI is created and the voxels belonging to arteries are identified in said arterial image.

3 . The method according to claim 2 , wherein the arterial image is an image based on first echo data or a combination of the first few echoes, or by calculating a normalized residual of the linear fit of the phase as a function of the echo time.

4 . The method according to claim 3 , wherein the arterial image is created using the following approach:

AI
=



I
Echol



〈



I
Echol



〉

-
1

,

AI


(

AI
<
0

)

=
0

,

AI


(

AI
>
1

)

=
1

,

wherein I Echo1 is the magnitude signal from the first echo or a combination of the first few echoes and | I Echo1 | is a low-pass filtered version of the magnitude signal from the first echo or a combination of the first few echoes.

5 . The method according to claim 2 , wherein in the echo combination step the magnitude information from the echoes is combined using the following non-linear combination:

I
=

1
N



∑

i
=
1

N





S
i



-
p

-
p

,

with



p

=

{

r


(

1
-

AI

2

t

)

for



AI

≤
t

r


(

1
-
AI

)

2


(

l
-
t

)

-
1

)

for



AI

>
t

6 . The method according to claim 1 , wherein arteries are identified by looking at voxels for which the phase evolution as a function of the echo time is not linear.

7 . The method according to claim 2 , wherein the phase masking is applie

Assignees

• Koninklijke Philips Nv

Inventors

• Gilbert Guillaume
• Chen Zhaolin

Classifications

• G01R33/5635 Primary

  Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA] · CPC title

• A61B5/489

  Blood vessels · CPC title

• A61B5/02

  Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow · CPC title

• G01R33/5608

  Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels (image data processing or generation, in general G06T) · CPC title

• A61B5/055

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