Ultrasonic diagnostic imaging with contrast agents

• US 5,833,613 A
• Filed: 09/27/1996
• Issued: 11/10/1998
• Est. Priority Date: 09/27/1996
• Status: Expired due to Term

• Current Assignee: Advanced Technology Materials, Inc. (Entegris Incorporated)
• Original Assignee: Advanced Technology Laboratories Inc (Koninklijke Philips N.V.)
• Inventors: Powers, Jeffry E., Averkiou, Michalakis, Bruce, Matthew
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US08/723,483
• Time in Patent Office: 774 Days
• Field of Search: 128/662.02, 424/9, 600/440, 600/443, 600/458
• US Class Current: 600/440
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• 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 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61B 8/463 characterised by displaying multiple images or images and diagnostic data on one display composite display in devices for short-range imaging with acoustic waves G01S7/52074
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61K 49/223 Microbubbles, hollow microspheres, free gas bubbles, gas microspheres
• CPC Class Codes: G01S 15/8959 using coded signals for correlation purposes
• CPC Class Codes: G01S 15/8963 using pulse inversion
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/52026 Extracting wanted echo signals Doppler systems G01S15/50; Doppler short range imaging systems G01S15/8979
• CPC Class Codes: G01S 7/52038 involving non-linear properties of the propagation medium or of the reflective target
• 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 7/52041 detecting modification of a contrast enhancer, e.g. detecting the destruction of a contrast agent by an acoustic wave, e.g. loss of correlation diagnostic techniques involving the use of contrast agents A61B8/481

Abstract

Apparatus and methods are disclosed for the detection and imaging of ultrasonic contrast agents. Ultrasonic apparatus is provided for coherent imaging of ultrasonic contrast agents, and for detecting harmonic contrast agents. The inventive apparatus includes a dual display for simultaneously viewing a real time image which displays the location of the contrast agent and a triggered contrast image. Methods of contrast agent detection and imaging include the measurement of perfusion rate characteristics, multizone contrast imaging, multifrequency contrast imaging, tissue perfusion display, and high PRF contrast image artifact elimination.

Claims

1. An ultrasonic diagnostic system for the coherent detection of ultrasonic contrast agents comprising:

an ultrasonic transducer probe for transmitting ultrasonic pulses into a body infused with an ultrasonic contrast agent and receiving ultrasonic echo signals following a pulse transmission;

a beamformer for forming coherent echo signals;

means for differentiating coherent echo signals received from two pulse transmissions;

means for detecting differentiated coherent echo signals; and

a display for displaying detected differentiated signals emanating from said ultrasonic contrast agent.

2. The ultrasonic diagnostic system of claim 1, wherein said means for detecting comprises an amplitude detector.

3. The ultrasonic diagnostic system of claim 2, further comprising an event discriminator for discriminating detected signals which emanated from a contrast agent.

4. The ultrasonic diagnostic system of claim 3, wherein said event discriminator comprises means for comparing detected signals against a threshold level.

5. The ultrasonic diagnostic system of claim 1, further comprising a B mode processor for producing B mode image signals,

wherein said display displays a B mode image combined with the display of detected differentiated signals emanating from said ultrasonic contrast agent.

6. An ultrasonic diagnostic system for the detection of a harmonic response of material inside the body comprising:

an ultrasonic transducer probe for transmitting ultrasonic pulses at a first frequency into the body and receiving harmonic ultrasonic echo signals following a pulse transmission;

a receiver for receiving harmonic signals emanating from material inside the body;

a programmable filter which filters said received harmonic signals with a passband excluding said first frequency and including a harmonic of said first frequency; and

a harmonic signal detector for detecting said received harmonic signals; and

a display for displaying received harmonic signals.

7. The ultrasonic diagnostic system of claim 6, wherein said programmable filter comprises a programmable digital filter.

8. The ultrasonic diagnostic system of claim 7, wherein the programmable characteristics of said digital filter include the weighting of received signals.

9. The ultrasonic diagnostic system of claim 6, wherein said programmable filter comprises an FIR filter.

10. The ultrasonic diagnostic system of claim 6, further comprising a B mode processor for producing B mode image signals,

wherein said programmable digital filter alternately provides signals for said B mode processor and said harmonic signal detector.

11. The ultrasonic diagnostic system of claim 10, wherein said programmable digital filter provides filtered signals for said B mode processor which include signals of a B mode passband and excludes said harmonic of said first frequency, and provides filtered signals for said harmonic signal detector which includes said harmonic of said first frequency and excludes signals of said first frequency.

12. The ultrasonic diagnostic system of claim 6, further comprising a three dimensional image processor for rendering three dimensional images of said received harmonic signals.

31. The ultrasonic diagnostic system of claim 6, wherein said ultrasonic transducer probe includes an array transducer, and further comprising a digital beamformer coupled to receive signals from said array transducer for producing digital beamformed harmonic signals.

32. The ultrasonic diagnostic system of claim 6, wherein said material comprises an ultrasonic contrast agent.

13. A method for ultrasonically detecting the perfusion rate of tissue by ultrasonic contrast agents comprising the steps of:

introducing an ultrasonic contrast agent of microbubbles into the tissue so as to perfuse said tissue;

transmitting an ultrasonic pulse which destroys microbubbles in said tissue; and

following the destruction of said microbubbles by a time interval, ultrasonically measuring the rate of microbubble reperfusion of said tissue during said time interval.

14. The method of claim 13, further comprising the steps of repeating said transmitting and measuring steps with a different time interval.

15. The method of claim 13, further comprising the steps of repeating said transmitting and measuring steps with the same time interval.

16. The method of claim 13, wherein said step of ultrasonically measuring comprises the step of acquiring echo signals following transmission of a second ultrasonic pulse into said tissue.

17. The method of claim 16, wherein said step of ultrasonically measuring further comprises the step of creating an ultrasonic image with said acquired echo signals.

18. The method of claim 17, wherein said step of transmitting comprises transmitting a relatively low frequency, high amplitude ultrasonic pulse into said tissue, and wherein said step of ultrasonically measuring comprises the step of transmitting a second ultrasonic pulse of relatively high frequency and low amplitude into said tissue.

19. A method of ultrasonically imaging tissue whose perfusion has been enhanced with an ultrasonic contrast agent in the presence of a blood pool containing contrast agent comprising the steps of:

insonifying said perfused tissue and blood pool;

receiving echoes returned from ultrasonic contrast agent in said perfused tissue and blood pool;

processing said received echoes for display by displaying greater intensity echoes with a lesser brightness or color intensity than echoes of lesser intensity,

whereby said perfused tissue is highlighted in the display relative to said blood pool.

20. A method of ultrasonically detecting a microbubble contrast agent in the presence of undesired tissue echoes comprising the steps of:

transmitting a first ultrasonic pulse into the body which causes a first response from said microbubbles;

receiving a desired microbubble response to said first ultrasonic pulse;

transmitting a second ultrasonic pulse into the body which causes a second response from said microbubbles

receiving a desired microbubble response to said second ultrasonic response and an undesired tissue echo response to said first ultrasonic pulse;

processing said received microbubble responses by incoherent detection, whereby said desired microbubble echoes and said undesired tissue echo exhibit different response characteristics; and

eliminating said undesired tissue echo by means of said different response characteristics.

21. The method of claim 20, wherein said first microbubble response is microbubble destruction and said second microbubble response is an absence of microbubble destruction.

22. The method of claim 21, wherein said undesired echo response to said first ultrasonic pulse emanates from tissue located deeper in the body than microbubbles which cause said first response.

23. The method of claim 20, wherein said processing step includes the step of differentiating the received microbubble responses to said first and second pulses.

24. An ultrasonic diagnostic system for the detection and display of ultrasonic contrast agents within the body comprising:

an ultrasonic transducer probe for transmitting ultrasonic pulses into a body infused with an ultrasonic contrast agent and receiving ultrasonic echo signals following a pulse transmission, including means for transmitting high and low energy ultrasonic pulses;

a trigger circuit responsive to a physiological function for triggering high energy ultrasonic pulse transmission;

a contrast signal processor for processing echoes received in response to high energy pulse transmission;

a B mode signal processor for processing echoes received in response to low energy pulse transmission; and

a display for displaying simultaneous real time B mode images and triggered contrast agent images.

25. The ultrasonic diagnostic system of claim 24, wherein said means for transmitting comprises means for selectively generating low frequency, high amplitude pulses or high frequency, low amplitude pulses.

26. The ultrasonic diagnostic system of claim 24, wherein said trigger circuit is responsive to a heartbeat waveform.

27. An ultrasonic diagnostic system for the detection and display of ultrasonic contrast agents within the body comprising:

an ultrasonic transducer probe for transmitting ultrasonic pulses into a body infused with an ultrasonic contrast agent and receiving ultrasonic echo signals following a pulse transmission, including means for transmitting high and low energy ultrasonic pulses;

a trigger circuit for periodically triggering high energy ultrasonic pulse transmission;

a contrast signal processor for processing echoes received in response to high energy pulse transmission;

a Doppler processor for processing Doppler echoes received by said transducer probe;

a B mode signal processor for processing echoes received in response to low energy pulse transmission; and

a display for displaying real time B mode images containing color Doppler image information and periodically containing contrast agent image information.

28. The ultrasonic diagnostic system of claim 27, wherein said trigger circuit comprises means for triggering high energy ultrasonic pulse transmission in response to a heartbeat signal.

29. The ultrasonic diagnostic system of claim 27, wherein said real time images comprise colorflow Doppler images.

30. The ultrasonic diagnostic system of claim 27, wherein the periodicity of said trigger circuit is selected by the system user.