Display for subtraction imaging techniques

• US 20030216644A1
• Filed: 05/17/2002
• Published: 11/20/2003
• Est. Priority Date: 05/17/2002
• Status: Active Grant

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Hall, Anne
• Granted Patent: US 6,796,944 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: G01S 15/8959 using coded signals for correlation purposes
• CPC Class Codes: G01S 15/8981 Discriminating between fixed and moving objects or between objects moving at different speeds, e.g. wall clutter filter
• CPC Class Codes: G01S 7/52039 exploiting the non-linear response of a contrast enhancer, e.g. a contrast agent diagnostic techniques involving the use of contrast agents A61B8/481
• CPC Class Codes: G01S 7/52074 Composite displays, e.g. split-screen displays; Combination of multiple images or of images and alphanumeric tabular information
• CPC Class Codes: G01S 7/52085 Details related to the ultrasound signal acquisition, e.g. scan sequences control of medical diagnostic ultrasound devices A61B8/54

Abstract

A method and apparatus for displaying reference background and flow ultrasound images. The method comprises: transmitting at least first and second broadband pulses to a common transmit focal position; receiving at least first and second ultrasound reflections associated with the at least first and second broadband pulses; forming a flow/contrast agent signal component based on the at least first and second ultrasound reflections; forming a B-mode background signal component based on independent processing of at least one of the at least first and second ultrasound reflections; and displaying an ultrasound image including a flow image component in a first image portion of a display and a B-mode reference image component based on at least one of the at least first and second ultrasound reflections, said B-mode reference image component displayed in a second image portion of said display.

Claims

1. A method for displaying ultrasound images, comprising:

transmitting at least first and second broadband pulses to a common transmit focal position;

receiving at least first and second ultrasound reflections associated with said at least first and second broadband pulses;

forming a flow/contrast agent signal component based on said at least first and second ultrasound reflections;

forming a B-mode background signal component based on independent processing of at least one of said at least first and second ultrasound reflections; and

displaying an ultrasound image including a flow image component in a first image portion of a display and a B-mode reference image component based on said at least one of said at least first and second ultrasound reflections, said B-mode reference image component displayed in a second image portion of said display.

2. The method of claim 1, wherein the transmitting step includes generating one of a coded and an uncoded waveform for multiple pulses.

3. The method of claim 2, further comprising:

forming an envelope of a signal including said flow/contrast agent signal component and said B-mode background signal component.

4. The method of claim 1, further comprising:

wall filtering across said first and second ultrasound reflections.

5. The method of claim 4, further comprising:

passing fundamental frequency components of a signal including said flow/contrast agent signal component and said B-mode background signal component.

6. The method of claim 1, further comprising:

passing harmonic frequency components of a signal including said flow/contrast agent signal component and said B-mode background signal component.

7. The method of claim 1, further comprising:

passing subharmonic frequency components of a signal including said flow/contrast agent signal component and said B-mode signal component.

8. The method of claim 1, further comprising:

passing ultraharmonic frequency components of a signal including said flow/contrast agent signal component and said B-mode signal component.

9. The method of claim 1, wherein the transmitting step includes transmitting a sequence of identical broadband pulses, centered at a fundamental frequency, to a particular transmit focal position.

10. The method of claim 1, further comprising:

bandpass filtering a fundamental frequency of said first and second ultrasound reflections substantially isolating a desired component of ultrasound reflections.

11. The method of claim 1, wherein the transmitting step includes encoding said sequence of at least two pulses with transmit codes to form a packet of coded broadband pulses transmitted with a given pulse repetition interval to a transmit focal position, said packet including up to four pulses.

12. The method of claim 1, wherein the transmitting step includes modulating each of said pulses with a predefined code sequence, each of said pulses having a predetermined transmit burst length.

13. The method of claim 1, wherein the transmitting step includes modulating first and second pulses with first and second separate predefined code sequences, respectively.

14. The method of claim 1, wherein the transmitting step includes modulating first through fourth pulses with first through fourth Golay code pair sequences, respectively.

15. The method of claim 1, wherein said first image portion and second image portion are side-by-side on said display.

16. The method of claim 1, wherein said first image portion and second image portion are juxtaposed on said display configured to allow an overlay display format of said flow image component and said B-mode reference image component.

17. The method of claim 16, wherein said overlay display format is configured to display said B-mode reference image component when said flow image component is absent.

18. The method of claim 17, wherein said overlay display format is configured to determine whether to display said B-mode reference image component using one of a thresholding and an adaptive process.

19. The method of claim 1, wherein said display includes a switch for operably switching said second image portion on and off.

20. A method to visualize tissue background and low amplitude signals simultaneously, without restricting visualization of the low amplitude signals, the method comprising:

creating a first image from a plurality of firings at a target to form corresponding waveforms;

processing said waveforms to form said first image, wherein said first image is indicative of the low amplitude signal;

displaying said first image on a display device;

creating a second image from a subset of said plurality of firings to form a subset of said corresponding waveforms;

processing said subset of said corresponding waveforms, wherein said second image is a B-mode image indicative of the tissue background proximate the flow signal; and

displaying said second image on said display device.

21. The method of claim 20, wherein said display device is configured to independently alter visualization of said second image without affect to said first image.

22. A method of operating an imaging system comprising a multiplicity of transducer elements for transmitting wave energy in response to electrical activation and transducing returned wave energy into electrical signals, and a display monitor for displaying a image having a first image portion which is a function of a flow image signal and having a second image portion which is a function of a reference image signal, said method comprising:

(a) activating transducer elements of said array to transmit focused wave energy encoded with a transmit code during first and second transmit events;

(b) forming first and second receive signals from electrical signals produced by said transducer elements subsequent to said first and second transmit events respectively;

(c) forming a reference image signal derived at least in part from independent processing of at least one of said first and second receive signals;

(d) compressing, bandpassing and wall filtering first and second fundamental signal components of said first and second receive signals respectively to form a flow signal;

(e) forming a flow image signal derived at least in part from said flow signal; and

(f) applying said flow image signal and said reference image signal to the display monitor, wherein said reference image is adjustable without affect to said flow image.

23. The method as recited in claim 22, further comprising:

(g) activating transducer elements of said array to transmit uncoded focused wave energy during a third transmit event;

(h) forming a third receive signal from electrical signals produced by said transducer elements subsequent to said third transmit event;

(i) bandpassing a harmonic signal component of said third receive signal; and

(j) forming said reference image signal from independent processing of said harmonic signal component and said flow signal.

24. The method as recited in claim 22, further comprising:

(g) activating transducer elements of said array to transmit uncoded focused wave energy during third and fourth transmit events, said uncoded focused wave energy of said third transmit event being of opposite polarity to said uncoded focused wave energy of said fourth transmit event;

(h) forming third and fourth receive signals from electrical signals produced by said transducer elements subsequent to said third and fourth transmit events respectively;

(i) bandpassing respective harmonic signal components of said third and fourth receive signals while substantially canceling respective fundamental signal components of said third and fourth receive signals respectively to form a harmonic background signal; and

(j) forming said reference image signal from independent processing of said harmonic background signal.

25. A method of operating an imaging system comprising a multiplicity of transducer elements for transmitting wave energy in response to electrical activation and transducing returned wave energy into electrical signals, and a display monitor for displaying an image having an image portion which is a function of a flow image signal, said method comprising of:

(a) activating transducer elements of said array to transmit focused wave energy encoded with a first Golay code of a Golay code pair during first and third transmit events and to transmit focused wave energy encoded with a second Golay code of said Golay code pair during second and fourth transmit events;

(b) forming first through fourth receive signals from electrical signals produced by said transducer elements subsequent to said first through fourth transmit events respectively;

(c) forming a reference image signal derived at least in part from independent processing of two of first through fourth receive signals;

(d) decoding, bandpassing and wall filtering first through fourth fundamental signal components of said first through fourth receive signals respectively to form a flow signal;

(e) forming a flow image signal derived at least in part from said flow signal; and

(f) applying said flow image signal and said reference image signal to the display monitor, wherein said reference image is adjustable without affect to said flow image.

26. An ultrasound medical diagnostic system for imaging stationary and moving reflectors for an area of interest in a patient, comprising:

a transmitter for transmitting a sequence of at least two pulses to a transmit focal position;

a receiver for receiving at least two echo signals associated with said sequence of at least two pulses, said echo signals containing a fundamental frequency component;

a first display processor configured to receive and process said at least two echo signals and having a filter for supplying a filtered signal containing flow image information for moving reflectors based on said at least two echo signals,

a second display processor configured to receive and independently process at least one of said at least two echo signals containing B-mode information for stationary reflectors based on said at least two echo signals, said B-mode information for stationary reflectors including said fundamental frequency component; and

a display for displaying a flow image of moving reflectors based on said filtered signal and a B-mode reference image of stationary reflectors based on said at least one of said at least two echo signals supplied by said second display processor.

27. The system of claim 26, wherein said display is adapted to combine said flow image and said B-mode reference image in order to illustrate the flow of moving reflectors relative to stationary reflectors.

28. The system of claim 26, wherein said display is adapted to combine a colorized said flow image and a gray scale said B-mode image for display.

29. The system of claim 26 further comprising means for amplitude detection of said filtered output signal to form a flow image signal.

30. The system of claim 26, wherein said transmitter is adapted to encode said sequence of at least two pulses with transmit codes to form a packet of coded broadband pulses transmitted with a given pulse repetition interval to a transmit focal position, said packet including up to four pulses.

31. The system of claim 26, wherein the transmitter is adapted to modulate each of said pulses with a predefined code sequence, each of said pulses having a predetermined transmit burst length.

32. The system of claim 26, wherein the transmitter is adapted to modulate first and second pulses with first and second separate predefined code sequences, respectively.

33. The system of claim 26, wherein the transmitter is adapted to modulate first through fourth pulses with first through fourth Golay code pair sequences.

34. An imaging system comprising:

a transducer array having a multiplicity of transducer elements for transmitting wave energy centered at a fundamental frequency in response to electrical activation and for transducing returned wave energy into electrical signals;

a display monitor for displaying an image having a first image portion which is a function of a flow image signal and a second image portion which is a function of a B-mode reference image signal; and

a computer programmed to perform;

(a) activating transducer elements of said array to transmit focused wave energy encoded with a transmit code during first and second transmit events;

(b) forming first and second receive signals from electrical signals produced by said transducer elements subsequent to said first and second transmit events respectively;

(c) processing at least one of said first and second receive signals to form a B-mode signal;

(d) compressing, bandpassing and wall filtering first and second fundamental signal components of said first and second receive signals respectively to form a flow signal;

(e) forming a B-mode reference image signal derived at least in part from said B-mode signal;

(f) forming a flow image signal derived at least in part from said flow signal; and

(g) applying said B-mode image signal and said flow image signal to said display monitor.

35. The system as recited in claim 34, wherein said first image portion and second image portion are side-by-side on said display.

36. The system of claim 34, wherein said first image portion and second image portion are juxtaposed on said display configured to allow an overlay display format of said flow image signal and said B-mode reference image signal.

37. The system of claim 36, wherein said overlay display format is configured to display said B-mode reference image signal when said flow image signal is absent.

38. The system of claim 37, wherein said overlay display format is configured to determine whether to display said B-mode reference image signal using one of a thresholding and an adaptive process.

39. The system of claim 34, wherein said display includes a switch for operably switching said second image portion on and off.

40. The system as recited in claim 34, wherein said transducer elements comprise piezoelectric elements for transmitting ultrasound waves in response to electrical activation and for transducing returned ultrasound waves into electrical signals.