Method and Apparatus for Ultrasound Synthetic Imagining

• US 20090234230A1
• Filed: 03/13/2008
• Published: 09/17/2009
• Est. Priority Date: 03/13/2008
• Status: Active Grant

• Current Assignee: SuperSonic Imagine SA (Hologic Incorporated)
• Original Assignee: SuperSonic Imagine SA (Hologic Incorporated)
• Inventors: Cohen, Claude Bacrie, Bercoff, Jeremy, Fink, Mathias, Tanter, Mickael, Montaldo, Gabriel
• Granted Patent: US 9,117,439 B2
• Time in Patent Office: Days
• US Class Current: 600/447
• CPC Class Codes: G01S 15/8915 using a transducer array
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 15/8977 using special techniques for image reconstruction, e.g. FFT, geometrical transformations, spatial deconvolution, time deconvolution
• CPC Class Codes: G01S 15/8995 Combining images from different aspect angles, e.g. spatial compounding
• CPC Class Codes: G01S 15/8997 using synthetic aperture techniques
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/52049 using correction of medium-induced phase aberration
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

Method for ultrasound imaging comprising at least the following steps:

• • a) a transmission step in which 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 having different spatial frequency content;
  • b) a coherence enhancing step in which, 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;
  • c) a beamforming step in which, 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.

Claims

1. Method for ultrasound imaging comprising at least the following steps:

a) a transmission step in which a plurality of ultrasonic waves are transmitted into an imaged region and a respective set of raw data is acquired by an array of transducers in response to each ultrasonic wave, said ultrasonic waves having different spatial frequency content, for each of a plurality of imaged locations in the region, each set of raw data representing the time signals received by the transducers in response to the corresponding ultrasonic wave;

b) a coherence enhancing step in which, 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;

c) a beamforming step in which, 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.

2. Method according to claim 1, wherein the ultrasonic waves are plane waves having different propagation directions.

3. Method according to claim 1, wherein the ultrasonic waves are divergent waves having different propagation directions.

4. Method according to claim 1, wherein the ultrasonic waves are spatio-temporal coded excitations.

5. Method according to claim 1, wherein the coherence enhancing step is performed using a fixed sound speed value.

6. Method according to claim 1, wherein the coherence enhancing step includes a global sound speed value estimation of the imaged region.

7. Method according to claim 1, wherein the coherence enhancing step includes global sound speed estimation for each imaged location of the region.

8. Method according to claim 1, wherein the coherence enhancing step includes phase aberration corrections.

9. Method according to claim 1, wherein in the coherence enhancing step, each virtual transmit focal zone is a straight line perpendicular to the transducer array.

10. Method according to claim 1, wherein the coherence enhancing step includes:

a first substep of computing a coherent data set for each virtual transmit focal zone by applying delays to the raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound is homogeneous in the region;

a second substep in which said delays are corrected by an estimation of aberrations in the imaged region based on the coherent data set calculated at the first substep, and the corrected delays are used to compute a new coherent data set by performing a virtual dynamic transmit focusing on said virtual transmit focal zone.

11. Method according to claim 10, wherein at least said second substep is performed several times.

12. Method according to claim 10, wherein in said second substep, the estimation of aberrations is done by cross correlating the coherent data corresponding to different transducers in each coherent data set.

13. Apparatus for ultrasound imaging, comprising:

means for transmitting a plurality of ultrasonic waves into a region, said ultrasonic waves having different spatial frequency content, for each of a plurality of imaged locations in the region;

means for acquiring a respective set of raw RF data is acquired in response to each ultrasonic wave;

means for synthesizing at least one set of coherent data is synthesized from each set of raw data for each of a plurality of virtual transmit focal zones in the region;

beamforming means for computing a beamformed signal along at least one direction using the set of coherent data for each of a plurality of locations included in each of the virtual transmit focal zones.