Method and apparatus for ultrasound synthetic imagining

Patent metadata

Field	Value
Publication number	US-9117439-B2
Application number	US-4764508-A
Country	US
Kind code	B2
Filing date	Mar 13, 2008
Priority date	Mar 13, 2008
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

A method for ultrasound imaging is provided. The method includes at least a transmission step, a coherence enhancing step, and a beamforming step. In the transmission step, a plurality of ultrasonic waves are transmitted into an imaged region and a set of raw data is acquired by an array of transducers in response to each ultrasonic wave. The ultrasonic waves have different spatial frequency content. In the coherence enhancing step, for each of a plurality of virtual transmit focal zones in the imaged region, at least one set of coherent data is synthesized from the sets of raw data. In the beamforming step, for each of a plurality of locations included in each of the virtual transmit focal zones, an image pixel is computed by beamforming, using the set of coherent data.

First claim

The invention claimed is:

1. An apparatus for ultrasound imaging, comprising:
means for transmitting a plurality of ultrasonic tilted plane waves into a region, said ultrasonic tilted plane waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region;
means for acquiring respective sets of non-coherent raw data, without receive beamforming, in response to said ultrasonic tilted plane waves, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic tilted plane wave;
means for synthesizing at least one set of coherent raw data from the plurality of sets of non-coherent raw data for each of a plurality of virtual transmit focal zones in an imaged region, the at least one set of coherent raw data corresponding to backscattered echoes resulting from said virtual transmit focal zone and being synthesized by coherent addition of said respective sets of non-coherent raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted plane waves;
beamforming means for computing a beamformed signal by receive beamforming along at least one direction using the set of coherent raw data for each of a plurality of locations included in each of the virtual transmit focal zones, thus obtaining an image of the imaged region,
wherein said virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, and
wherein said means for synthesizing at least one set of coherent raw data include at least means for computing a coherent raw data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula:

RFcoherent
⁡

(

x
1

,
x
,
z

)

=

∑
α

⁢

⁢

B
⁡

(
α
)

⁢

RFraw
⁡

(

x
,

τ
⁡

(

α
,

x
1

,
x
,
z

)

,
α

)

,

where:
x, z are coordinates, respectively along an axis X of the linear transducer array ( 2 ) and along an axis Z perpendicular to the axis X,
x 1 is a lateral position of one of said straight lines along axis X,
α are the respective angles of inclination of the direction propagation of the plane waves with regard to axis Z,
RFcoherent(x 1 ,x,z) is a set of coherent data corresponding to one straight line of lateral position x 1 ,
RFraw(x, τ(a, x 1 , x, z), α) are data from the sets of raw data RFraw,
B(α) is a weighting function for each angle contribution,
τ(α, x 1 , x, z) is a travel time computed according to the following formula:

τ
⁡

(

α
,

x
1

,
x
,
z

)

=

1
c

⁡

[

(

z
⁢

⁢
cos
⁢

⁢
α

+

x
1

⁢
sin
⁢

⁢
α

)

+

z
2

+

(

x
-

x
1

)

2

]

.

2. An apparatus for ultrasound imaging, comprising:
means for transmitting a plurality of ultrasonic tilted divergent waves into a region, said ultrasonic tilted divergent waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region;
means for ac

Assignees

• Bercoff Jeremy
• Cohen Bacrie Claude
• Tanter Mickael
• Fink Mathias
• Montaldo Gabriel
• Supersonic Imagine

Inventors

• Bercoff Jeremy
• Cohen Bacrie Claude
• Tanter Mickael
• Fink Mathias
• Montaldo Gabriel

Classifications

• G01S15/8977

  using special techniques for image reconstruction, e.g. FFT, geometrical transformations, spatial deconvolution, time deconvolution · CPC title

• G10K11/346 Primary

  using phase variation · CPC title

• G01S15/8997

  using synthetic aperture techniques · CPC title

• G01S7/52049

  using correction of medium-induced phase aberration · CPC title

• G01S15/8927

  using simultaneously or sequentially two or more subarrays or subapertures · CPC title