Combined B-mode / tissue doppler approach for improved cardiac motion estimation in echocardiographic images

Patent metadata

Field	Value
Publication number	US-9629615-B1
Application number	US-201414480313-A
Country	US
Kind code	B1
Filing date	Sep 8, 2014
Priority date	Sep 6, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method for cardiac motion estimation includes: receiving a set of echocardiographic images of a heart, the echocardiographic images including B-mode ultrasonic images and Tissue Doppler Imaging (TDI) images; and calculating, by the image processing machine, a motion field representing the motion of the heart using the B-mode ultrasonic images and applying a velocity constraint from the TDI images. A system for cardiac motion estimation, includes: an imaging device configured to acquire a set of echocardiographic images of a heart, the echocardiographic images including B-mode ultrasonic images and TDI images; a data storage device in communication with the imaging device and configured to store the set of echocardiographic images; an image processing machine in communication with the data storage device and configured to calculate a motion field representing the motion of the heart using the B-mode ultrasonic images and applying a velocity constraint from the TDI images.

First claim

What is claimed is:

1. A method for cardiac motion estimation, comprising:
receiving, by an image processing machine, a set of echocardiographic images of a heart, the echocardiographic images including B-mode ultrasonic images and Tissue Doppler Imaging (TDI) images;
transforming, by the image processing machine, the set of echocardiographic images of the heart into a motion field representing the motion of the heart by simultaneously combining motion components in a plurality of directions from speckle data from the B-mode ultrasonic images and information from the TDI images; and
outputting, to an output device, the motion field representing motion of the heart.

2. The method of claim 1 ,
wherein transforming the set of echocardiographic images of the heart into the motion field utilizes an optical flow energy function which combines:
B-mode intensity constancy;
motion smoothness; and
Doppler/B-mode velocity similarity.

3. The method of claim 2 ,
wherein B-mode intensity constancy is formulated as:
E data =|I ( p+w+dw )− I ( p )| 2

where:
p=(x, y, t) and the flow field is w(p)=(u(p),v(p),1) where u and v are the motion vectors and x, y, and t are the spatial and temporal dimensions;
I(p) is the pixel intensity at location p and I(p+w) is the pixel intensity from a subsequent image at location p+w, assuming that the pixel intensity is the same along the motion vector;

which is linearized using Taylor series expansion as:
I t ( p+w+dw )− I ( p )= I t ( p )+ I x ( p ) du ( p )+ I y ( p ) dv ( p )

with
I x ⁡ ( p ) = ∂ I ⁡ ( p + w ) ∂ x I y ⁡ ( p ) = ∂ I ⁡ ( p + w ) ∂ y I t ( p )= I ( p+w )− I ( p );

wherein motion smoothness is formulated as:
E s =|∇( u+du )| 2 +|∇( v+dv )| 2

with



∇

(

u
+
du

)



2

=

(

∂

(

u
+
du

)

∂
x

)

2

+

(

∂

(

u
+
du

)

∂
y

)

2

;

and
wherein Doppler/B-mode velocity similarity is formulated as:
E tdi =( {right arrow over (v)} T {right arrow over (v)} t −w tdi ) 2 =( u t u+v t v−w tdi ) 2
where:
{right arrow over (v)}=(u, v) is the B-mode velocity;
{right arrow over (v t )}=(u t , v t ) is the transducer orientation; and
w tdi is the TDI velocity;

such that the energy function to be minimized is:

E
⁡

(

u
,
v

)

=

E
data

+

α
⁢

⁢

E
s

+

βψ
⁡

(

E
tdi

)

=

∫
Ω

⁢

(



I
⁡

(

P
+
w
+

ⅆ
w

)

-

I
⁡

(
p
)



2

+

α
⁡

(



∇

(

u
+
du

)



2

+

Assignees

• Univ Louisville Res Found Inc

Inventors

• Tavakoli Vahid
• Amini Amir A

Classifications

• G16H50/30

  for calculating health indices; for individual health risk assessment · CPC title

• A61B8/463

  characterised by displaying multiple images or images and diagnostic data on one display · CPC title

• A61B8/0883

  for diagnosis of the heart · CPC title

• A61B8/5223 Primary

  for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012) · CPC title

• A61B8/488

  involving Doppler signals · CPC title