Ultrasonic imaging to detect coronary artery stenosis at rest

• US 6,730,036 B2
• Filed: 02/28/2002
• Issued: 05/04/2004
• Est. Priority Date: 02/28/2002
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.), University of Virginia
• Inventors: Rafter, Patrick G., Wei, Kevin, Kaul, Sanjiv, Witt, Jerome F., Brock-Fisher, George A.
• Primary Examiner(s): Imam, Ali M.
• Application Number:
  US10/086,027
• Publication Number:
  US 20030163048A1
• Time in Patent Office: 796 Days
• Field of Search: 600/407-471, 736/25, 736/26, 367/7, 367/11, 367/130, 367/138, 128/916, 424/9.351, 424/9.35, 424/9.51, 424/9.52, 424/617, 424/9.34
• US Class Current: 600/458
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• 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 8/0891 for diagnosis of blood vessels
• 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 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal

Abstract

Ultrasonic imaging to receive a signal from contrast agent microbubbles in arterioles of a myocardium, without being masked by a signal from microbubbles in capillaries of the myocardium. For example, high power ultrasonic energy is emitted to destroy microbubbles in the arterioles and capillaries. A time delay passes from the destruction. The time delay is sufficiently long to allow the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles. Ultrasonic imaging is then performed to receive a signal between harmonics from the microbubbles refilled in the arterioles. Various other destructive and non-destructive imaging techniques are disclosed.

Claims

1. A method comprising:

destroying contrast agent microbubbles in arterioles and capillaries of a myocardium; and

at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging to receive a signal between adjacent harmonics of an ultrasonic fundamental frequency, or less than a first harmonic, from microbubbles refilled in the arterioles.

2. A method comprising:

destroying contrast agent microbubbles in arterioles and capillaries of a myocardium;

at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging by

emitting ultrasonic energy at a fundamental frequency in the myocardium,

receiving a response in the myocardium generated in response to the emitted ultrasonic energy, and

filtering the received response with a filter having a passband between adjacent harmonics of the fundamental frequency and which substantially filters out energy at the adjacent fundamentals, or less than a first harmonic and which substantially filters out energy at the first harmonic, to thereby receive a signal from microbubbles refilled in the arterioles.

3. A method as in claim 2, wherein said destroying comprises:

emitting ultrasonic energy into the myocardium at an intensity causing the microbubbles to be destroyed.

4. A method as in claim 2, wherein

said destroying comprises transmitting ultrasonic energy in destructive frames which are controlled in at least one of the group consisting of number or rate to coincide with one complete heart cycle.

5. A method as in claim 2, wherein

said destroying comprises transmitting ultrasonic energy in destructive frames which are controlled to coincide with one complete heart cycle,

said emitting ultrasonic energy emits ultrasonic energy in frames, and

said time delay is from transmission of a last destructive frame in a sequence of destructive frames to emission of a first frame by said emitting, said time delay being greater than or equal to a minimum interframe time and less than or equal to a time corresponding to one heart cycle.

6. A method comprising:

destroying contrast agent microbubbles in arterioles and capillaries of a myocardium; and

at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging using a power Doppler mode to receive a signal from microbubbles refilled in the arterioles.

7. A method as in claim 6, wherein said performing ultrasonic imaging receives an ultrasonic response including the signal from the microbubbles refilled in the arterioles and a tissue signal, said performing ultrasonic imaging comprising:

wall filtering the received ultrasonic response to remove the tissue signal.

8. A method as in claim 6, wherein said performing ultrasonic imaging comprises:

triggering ultrasonic imaging frames during a relatively stationary portion of the cardiac cycle.

9. A method as in claim 6, wherein said performing ultrasonic imaging receives an ultrasonic response including the signal from the microbubbles refilled in the arterioles and a tissue signal, said performing ultrasonic imaging further comprising:

adaptive wall filtering the received ultrasonic response to lock onto tissue motion and thereby remove the tissue signal.

10. A method as in claim 7, wherein said performing ultrasonic imaging further comprises:

adaptive wall filtering the received ultrasonic response to lock onto tissue motion to remove the tissue signal.

11. A method as in claim 6, wherein said destroying comprises:

emitting ultrasonic energy into the myocardium at an intensity causing the microbubbles to be destroyed.

12. A method as in claim 6, wherein

said destroying comprises transmitting ultrasonic energy in destructive frames which are controlled in at least one of the group consisting of number or rate to coincide with one complete heart cycle.

13. A method as in claim 6, wherein

said destroying comprises transmitting ultrasonic energy in destructive frames which are controlled to coincide with one complete heart cycle,

said performing ultrasonic imaging emits ultrasonic energy in frames, and

said time delay is from transmission of a last destructive frame in a sequence of destructive frames to emission of a first frame by said performing ultrasonic imaging, said time delay being greater than or equal to a minimum interframe time and less than or equal to a time corresponding to one heart cycle.

14. A method comprising:

transmitting ultrasonic energy into a myocardium at an intensity causing contrast agent microbubbles in arterioles and capillaries of the myocardium to be destroyed; and

at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging at an intensity lower than said intensity of said transmitted ultrasonic energy.

15. A method as in claim 14, wherein the ultrasonic imaging is performed to detect refilling of microbubbles in arterioles in real-time.

16. A method as in claim 14, wherein said performing ultrasonic imaging comprises:

detecting refilling of microbubbles in the arterioles in real-time, and

quantifying and displaying a signal from the detected refilling.

17. A method as in claim 14, wherein

said transmitting ultrasonic energy comprises transmitting ultrasonic energy in frames which are controlled in at least one of the group consisting of number or rate to coincide with one complete heart cycle.

18. A method as in claim 14, wherein said performing ultrasonic imaging comprises:

performing ultrasonic imaging using a non-destructive imaging mode to receive an ultrasonic response which includes a signal from the microbubbles and a substantially linear tissue signal, the non-destructive imaging mode removing the substantially linear tissue signal from the ultrasonic response, to thereby receive the signal from the microbubbles.

19. A method as in claim 18, wherein said performing ultrasonic imaging comprises:

wall filtering the received ultrasonic response to remove the substantially linear tissue signal.

20. A method as in claim 18, wherein said performing ultrasonic imaging comprises:

adaptive wall filtering the received ultrasonic response to remove the substantially linear tissue signal.

21. A method as in claim 18, wherein the non-destructive imaging mode is one of the group consisting of Power Modulation and Phase Modulation.

22. A method as in claim 19, wherein the non-destructive imaging mode is one of the group consisting of Power Modulation and Phase Modulation.

23. A method as in claim 20, wherein the non-destructive imaging mode is one of the group consisting of Power Modulation and Phase Modulation.

24. A method as in claim 18, wherein the non-destructive imaging mode includes a combination of Power Modulation and Phase Modulation.

25. An apparatus comprising:

means for destroying contrast agent microbubbles in arterioles and capillaries of a myocardium; and

means for, at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging to receive an ultrasonic response between harmonics of an ultrasonic fundamental frequency, or less than a first harmonic, from microbubbles refilled in the arterioles.

26. An apparatus comprising:

means for destroying contrast agent microbubbles in arterioles and capillaries of a myocardium; and

means for, at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging using a power Doppler mode to receive an ultrasonic signal from microbubbles refilled in the arterioles.

27. An apparatus comprising:

means for transmitting ultrasonic energy into a myocardium at an intensity causing contrast agent microbubbles in arterioles and capillaries of the myocardium to be destroyed; and

means for, after a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing ultrasonic imaging at an intensity lower than said intensity of said transmitted ultrasonic energy.

28. A method comprising:

destroying contrast agent microbubbles in arterioles and capillaries of a myocardium; and

at a time delay from the destruction of the microbubbles which is sufficiently long to cause the arterioles to refill with microbubbles and sufficiently short so that the capillaries do not completely refill with microbubbles, performing an imaging modality to receive a signal between adjacent harmonics of an ultrasonic fundamental frequency, or less then a first harmonic, from microbubbles refilled in the arterioles.

29. A method as in claim 28, further comprising:

displaying an image in accordance with the received signal; and

displaying cyclical backscatter via a color coded overlay on the displayed image.

30. An apparatus comprising:

an imaging device in which contrast agent is introduced in the myocardium and, in accordance with the introduced contrast agent, the imaging device including means for destroying an imageable manifestation of the contrast agent and means for, at a time delay from the destruction of the contrast agent which is sufficiently long to cause the arterioles to refill with imageable manifestation of the contrast agent and sufficiently short so that the capillaries do not completely refill with the imageable manifestation of the contrast agent, measuring a variation in the myocardium over a cardiac cycle.

31. An apparatus as in claim 30, wherein the imaging device is a magnetic resonance imaging (MRI) imaging device.

32. An apparatus as in claim 30, wherein the imaging device is a computed tomography (CT) imaging device.