Adaptive receive aperture for ultrasound image reconstruction

• US 6,866,632 B1
• Filed: 09/18/2002
• Issued: 03/15/2005
• Est. Priority Date: 09/18/2002
• Status: Active Grant

• Current Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Original Assignee: Zonare Medical Systems Incorporated (Excelsior Union Ltd.)
• Inventors: McLanghlin, Glen W., Ji, Ting-Lan, Mo, Larry Y. L., Chou, Ching-Hua
• Primary Examiner(s): IMAM, ALI M
• Application Number:
  US10/246,854
• Time in Patent Office: 909 Days
• Field of Search: 600437-472, 367/7, 367/11, 367/130, 367/138, 736/25, 736/26, 128/916
• US Class Current: 600/443
• CPC Class Codes: G01S 15/8915 using a transducer array
• 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 7/52047 for elimination of side lobes or of grating lobes; for increasing resolving power
• CPC Class Codes: Y10S 128/916 Ultrasound 3-D imaging

Abstract

A method for adaptively determining reconstruction signals in an ultrasound system comprises determining a size of a receive aperture, comparing the size of receive aperture at each imaging point with a predetermined number of reconstruction channels, if the size of the receive aperture is not greater than the number of reconstruction channels, processing received echo signals for the receive aperture to produce an ultrasonic image, and if the size of the receive aperture is greater than the number of reconstruction channels, preprocessing the received echo signals to produce reconstruction signals, the number of reconstruction signals being equal to the number of reconstruction channels. The reconstruction signals are further processed to produce an ultrasonic image. In one embodiment, the receive aperture is a function of location of an imaging point in a medium under investigation.

Claims

1. An ultrasound system comprising:

a transducer array including a plurality of transducer elements, each transducer element configured to receive ultrasound signals and convert the received ultrasound signals into echo signals;

a multiplexer configured to selectively couple individual transducer elements, from the plurality of transducer elements, for passing selected echo signals; and

a reconstruction unit configured to receive the selected echo signals from the individual transducer elements selected by the multiplexer, the reconstruction unit including a receive aperture control engine configured to use the selected echo signals to adaptively determine a set of reconstruction signals.

2. The ultrasound system of claim 1, wherein the reconstruction unit is further configured to process the set of reconstruction signals to produce in-phase and quadrature signals that are further processed by the ultrasound system to produce an ultrasound image.

3. The ultrasound system of claim 1, wherein the receive aperture control engine is further configured to adaptively determine a number of reconstruction signals by comparing a number of channels of a receive aperture with a number of reconstruction channels.

4. The ultrasound system of claim 3, wherein the number of channels of the receive aperture depends upon a location of an imaging point in a region of interest in a medium under investigation.

5. The ultrasound system of claim 3, wherein the receive aperture control engine is further configured to determine the number of reconstruction signals to be equal to the number of channels of the receive aperture if the number of channels of the receive aperture is not greater than the number of reconstruction channels.

6. The ultrasound system of claim 5, wherein the receive aperture control engine is further configured to output the selected echo signals as the set of reconstruction signals.

7. The ultrasound system of claim 3, wherein the receive aperture control engine is further configured to determine the number of reconstruction signals to be equal to the number of reconstruction channels if the number of channels of the receive aperture is greater than the number of reconstruction channels.

8. The ultrasound system of claim 7, wherein the receive aperture control engine is further configured to preprocess the selected echo signals to produce the set of reconstruction signals.

9. The ultrasound system of claim 7, wherein the receive aperture control engine, is further configured to group qualified channels in the receive aperture such that the number of reconstruction signals is not less than the number of reconstruction channels.

10. The ultrasound system of claim 9, wherein the receive aperture control engine is further configured to group qualified channels in the receive aperture by taking a weighted sum of echo signals corresponding to the qualified channels.

11. The ultrasound system of claim 10, wherein each channel in a qualified group of channels has a weight equal to a weight of the other channels in the qualified group of channels.

12. The ultrasound system of claim 10, wherein each channel in a qualified group of channels has a weight based on a receive aperture apodization function for a current image point.

13. The ultrasound system of claim 9, wherein a group of channels in the receive aperture is qualified if the group of channels is a pair of adjacent channels and a phase difference between echo signals for the channels in the pair is less than a specified value.

14. The ultrasound system of claim 9, wherein a group of channels in the receive aperture is qualified if the channels in the group are symmetric about an imaging point.

15. The ultrasound system of claim 9, wherein the receive aperture control engine is further configured to skip channels in the receive aperture such that the number of reconstruction signals equals the number of reconstruction channels.

16. The ultrasound system of claim 15, wherein the receive aperture control engine is configured to skip channels in the receive aperture by ignoring signals on the skipped channels.

17. A method comprising the steps of:

receiving ultrasound signals by a transducer array including a plurality of transducer elements;

converting the ultrasound signals into echo signals by the transducer array;

selectively coupling individual transducer elements in the transducer array for passing the selected echo signals to a reconstruction unit; and

using the selected echo signals to adaptively determine a set of reconstruction signals.

18. The method of claim 17, further comprising the step of processing the set of reconstruction signals to produce in-phase and quadrature signals that are further processed to produce an ultrasound image.

19. The method of claim 17, wherein the step of using the selected echo signals, includes comparing a number of channels of a receive aperture with a number of reconstruction channels to determine a number of reconstruction signals.

20. The method of claim 19, wherein the number of channels of the receive aperture depends upon a location of an imaging point in a region of interest in a medium under investigation.

21. The method of claim 19, wherein the step of using the selected echo signals includes determining the number of reconstruction signals to be equal the number of channels of the receive aperture if the number of channels of the receive aperture is not greater than the number of reconstruction channels.

22. The method of claim 19, wherein the step of using the selected echo signals includes determining the number of reconstruction signals to be equal to the number of reconstruction channels if the number of channels of the receive aperture is greater than the number of reconstruction channels.

23. The method of claim 22, wherein the step of using the selected echo signals further includes preprocessing the selected echo signals to produce the set of reconstruction signals.

24. The method of claim 22, further comprising the step of grouping qualified channels in the receive aperture such that the number of reconstruction data signals is not less than the number of reconstruction channels.

25. The method of claim 24, wherein the step of grouping qualified channels in the receive aperture includes taking a weighted sum of echo signals corresponding to the qualified channels.

26. The method of claim 25, wherein each channel in a group of qualified channels has a weight equal to a weight of the other channels in the group of qualified channels.

27. The method of claim 25, wherein each channel in a group of qualified channels has a weight based on a receive aperture apodization function for a current image point.

28. The method of claim 24, wherein a group of channels in the receive aperture is qualified if the group of channels is an adjacent pair of channels and a phase difference between echo signals for the channels of the pair is less than a specified value.

29. The method of claim 24, wherein a group of channels in the receive aperture is qualified if the channels in the group are symmetric about an imaging point.

30. The method of claim 24, further comprising the step of skipping channels in the receive aperture such that the number of reconstruction signals equals the number of reconstruction channels.

31. The method of claim 30, wherein the step of skipping channels in the receive aperture includes ignoring signals on the skipped channels.

32. A method for adaptively determining reconstruction signals in an ultrasound system, the method comprising the steps of:

determining a size of a receive aperture based on location of an imaging point in a medium under investigation;

receiving echo signals for the receive aperture at a reconstruction unit via a transducer array and a multiplexer;

comparing the size of the receive aperture with a predetermined number of reconstruction channels;

if the size of the receive aperture is not greater than the predetermined number of reconstruction channels, processing the echo signals for the receive aperture to produce an ultrasound image; and

if the size of the receive aperture is greater than the predetermined number of reconstruction channels, preprocessing the echo signals to produce reconstruction signals, the number of reconstruction signals being equal to the number of reconstruction channels, and processing the preprocessed reconstruction signals to produce an ultrasound image.

33. The method of claim 32, wherein the step of preprocessing the echo signals includes grouping qualified channels in the receive aperture such that the number of reconstruction signals is not less than the number of reconstruction channels.

34. The method of claim 33, wherein grouping qualified channels in the receive aperture includes taking a weighted sum of qualified channels.

35. The method of claim 33, wherein a group of channels in the receive aperture is qualified if the group of channels is an adjacent pair of channels and a phase difference between echo signals for the channels of the pair is less than a specified value.

36. The method of claim 33, wherein a group of channels in the receive aperture is qualified if the channels in the group are symmetric about an imaging point.

37. The method of claim 33, wherein the step of preprocessing the echo signals further includes skipping channels in the receive aperture such that the number of reconstruction signals is equal to the number of reconstruction channels.

38. The method of claim 37, wherein skipping channels in the receive aperture includes ignoring received signals on selected channels in the receive aperture.

39. A system for adaptively determining reconstruction signals, comprising:

size determining means configured to determine a size of a receive aperture based on location of an imaging point in a medium under investigation;

echo signal receiving means configured to receive echo signals for the receive aperture;

size comparing means configured to compare the size of the receive aperture with a predetermined number of reconstruction channels;

echo signal processing means configured to process the echo signals for the receive aperture to produce an ultrasound image if the size of the receive aperture is not greater than the predetermined number of reconstruction channels; and

echo signal preprocessing means configured to preprocess the echo signals to produce reconstruction signals, the number of reconstruction signals being equal to the number of reconstruction channels, if the size of the receive aperture is greater than the predetermined number of reconstruction channels, the echo signal processing means further configured to process the reconstruction signals to produce an ultrasound image.

40. A computer-readable medium comprising program instructions for adaptively determining reconstruction signals by performing the steps of:

determining a size of a receive aperture based on location of an imaging point in a medium under investigation;

receiving echo signals for the receive aperture at a reconstruction unit via a transducer array and a multiplexer;

comparing the size of the receive aperture with a predetermined number of reconstruction channels;

if the size of the receive aperture is not greater than the predetermined number of reconstruction channels, processing the echo signals for the receive aperture to produce an ultrasound image; and

if the size of the receive aperture is greater than the predetermined number of reconstruction channels, preprocessing the echo signals to produce reconstruction signals, the number of reconstruction signals being equal to the number of reconstruction channels, and processing the reconstruction signals to produce an ultrasound image.