Diagnostic medical ultrasound image and system for contrast agent imaging

• US 6,645,147 B1
• Filed: 11/25/1998
• Issued: 11/11/2003
• Est. Priority Date: 11/25/1998
• Status: Expired due to Term

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Acuson Corporation (Siemens AG)
• Inventors: Plugge, Jay S., Jackson, John I., Gardner, Edward A.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): PATEL, MAULIN M
• Application Number:
  US09/200,648
• Time in Patent Office: 1,812 Days
• Field of Search: 600/458, 600/443, 600/444, 600/454, 600/462, 600/460, 600/459, 382/294, 382/295
• US Class Current: 600/458
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• 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 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/14 Echo-tomography
• CPC Class Codes: A61B 8/445 Details of catheter construction
• 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

A method and system for contrast agent imaging with a catheter transducer is provided. The catheter transducer may comprise an intra-vascular, intra-cardiac or other transducer for insertion into or through a small space. The catheter transducer is inserted within the heart or other portion of a patient. Contrast agents, such as micro-spheres, are injected into the patient. Using the catheter transducer, ultrasonic acoustic energy is transmitted, and reflected energy is received. The reflected energy is responsive to the contrast agents. An image processor generates an image of the tissue and contrast agents as a function of the reflected energy. The image provides an indication of perfusion. Alternatively, the ultrasound system calculates perfusion. By generating intra-vascular images or data, interference from other tissues is avoided. Therefore, the perfusion information obtained may have higher resolution. Images with better resolution better assist doctors in medical diagnosis.

Claims

1. A method for generating contrast images from within a body with an ultrasound system, the method comprising the steps of:

(a) transmitting ultrasonic acoustic energy from a catheter transducer;

(b) receiving reflected energy responsive to step (a) and contrast agents without interference from intervening structures with the catheter transducer; and

(c) generating an image responsive to the reflected energy.

2. The method of claim 1 further comprising step (d) obtaining information at a harmonic of the transmitted ultrasonic acoustic energy from the reflected energy;

wherein the image is responsive to the information at the harmonic.

3. The method of claim 1 further comprising step (d) estimating perfusion as a function of the reflected energy.

4. The method of claim 3 wherein step (d) comprises calculating a contrast agent transit time as a function of the reflected energy.

5. The method of claim 3 wherein step (d) comprises:

(d1) substantially destroying contrast agents; and

(d2) calculating perfusion as a function of the reflected energy and time.

6. The method of claim 3 wherein step (d) comprises:

(d1) repeating step (a);

(d2) triggering step (d1) at a trigger rate;

(d3) adjusting the trigger rate in response to the reflected energy; and

(d4) calculating perfusion as a function of the triggering rate.

7. The method of claim 3 wherein step (d) comprises estimating the perfusion as an absolute perfusion calculation.

8. The method of claim 3 wherein step (d) comprises estimating the perfusion as a calculation selected from the group consisting of:

wash-in, washout and wash-in wash-out.

9. The method of claim 3 wherein step (d) comprises estimating the perfusion as a function of a triggering rate.

10. The method of claim 1:

further comprising repeating steps (a), (b) and (c); and

wherein at least one repetition of step (a) is associated with a first power level of the ultrasonic acoustic energy and at least another repetition of step (a) is associated with a second power level that is less than the first power level.

11. The method of claim 1 further comprising step (d) determining an area value responsive to the reflected energy.

12. The method of claim 1:

further comprising repeating steps (a) and (b), at least one transmission of ultrasonic acoustic energy responsive to a first phase and at least another transmission of ultrasonic acoustic energy responsive to a second phase that is shifted from the first phase;

further comprising step (d) combining reflected energy responsive to the first phase with reflective energy responsive to the second phase;

wherein the image is responsive to step (d).

13. The method of claim 1 further comprising step (d) detecting tissue motion.

14. The method of claim 13 wherein step (d) comprises a process selected from the group of:

(i) Doppler processing (ii) correlation processing, (iii) image display processing as a function of time and (iv) combinations thereof.

15. The method of claim 13 further comprising (e) injecting contrast agents after step (d).

16. The method of claim 15 further comprising step (f) estimating perfusion as a function of the reflected energy after step (e).

17. The method of claim 1 wherein step (a) comprises transmitting the ultrasonic acoustic energy from a plurality of elements, each of the plurality of elements spaced at least one wavelength from other ones of the plurality of elements.

18. The method of claim 1 wherein step (a) comprises transmitting from a transducer selected from the group consisting of intra-vascular and intra-cardiac.

19. The method of claim 1 wherein step (c) comprises processing selected from the group consisting of:

applying a wall filter to detect contrast agents, triggering to detect contrast agents and combinations thereof.

20. The method of claim 1 wherein step (a) comprises transmitting from a linear array of elements.

21. An ultrasound system dapted for generating contrast images from within a body without interference from intervening structures, the system comprising:

a catheter transducer for transmitting ultrasonic acoustic energy and for receiving reflected energy responsive to the transmitted ultrasonic acoustic energy and contrast agents without interference from intervening structures; and

an image processor for generating an image responsive to the reflected energy.

22. The system of claim 21 wherein the image processor is operable to obtain information at a harmonic of the transmitted ultrasonic acoustic energy from the reflected energy and the image is responsive to the information at the harmonic.

23. The system of claim 21 further comprising an estimate of perfusion responsive to the reflected energy.

24. The system of claim 21 further comprising a means for triggering transmission of the ultrasonic acoustic energy.

25. The system of claim 21 further comprising:

a beamformer operatively connected between the catheter transducer and the image processor; and

a beamformer controller operative to cause a first transmission of the ultrasonic acoustic energy at a first power level and to cause a second transmission of the ultrasonic acoustic energy at a second power level that is less than the first power level.

26. The system of claim 21 further comprising an estimate of an area responsive to the reflected energy.

27. The system of claim 21 further comprising:

a beamformer operatively connected between the catheter transducer and the image processor;

a beamformer controller operative to cause a first transmission of the ultrasonic acoustic energy at a first phase and to cause a second transmission of the ultrasonic acoustic energy at a second phase that is shifted from the first phase;

wherein the image processor is operable to combine reflected energy responsive to the first phase with reflective energy responsive to the second phase; and

wherein the image is responsive to the result of the combination.

28. The system of claim 21 wherein the image processor comprises a Doppler processor for generating tissue motion information.

29. The system of claim 21 wherein the catheter transducer comprises a plurality of elements, each of the plurality of elements spaced at least one wavelength from other ones of the plurality of elements.

30. The system of claim 21 wherein the catheter transducer comprises a transducer selected from the group consisting of:

intra-vascular and intra-cardiac.

31. The system of claim 21 wherein the image processor comprises a Doppler processor and wall filter.

32. The system of claim 21 wherein the catheter transducer comprises a linear array of elements.

33. A method for generating contrast images from within a body with an ultrasound system, the method comprising the steps of:

(a) transmitting ultrasonic acoustic energy from a catheter transducer comprising a linear array of elements;

(b) receiving reflected energy responsive to step (a) and contrast agents with the catheter transducer; and

(c) generating an image responsive to the reflected energy.

34. The method of claim 33 further comprising step (d) obtaining information at a second harmonic of the transmitted ultrasonic acoustic energy from the reflected energy;

wherein the image is responsive to the information at the second harmonic.

35. The method of claim 33 further comprising step (d) estimating perfusion as a function of the reflected energy.

36. The method of claim 33:

further comprising repeating steps (a), (b) and (c); and

wherein at least one repetition of step (a) is associated with a first power level of the ultrasonic acoustic energy and at least another repetition of step (a) is associated with a second power level that is less than the first power level.

37. The method of claim 33 further comprising step (d) determining an area value responsive to the reflected energy.

38. The method of claim 33:

further comprising repeating steps (a) and (b), at least one transmission of ultrasonic acoustic energy responsive to a first phase and at least another transmission of ultrasonic acoustic energy responsive to a second phase that is shifted from the first phase;

further comprising step (d) combining reflected energy responsive to the first phase with reflective energy responsive to the second phase;

wherein the image is responsive to step (d).

39. The method of claim 33 further comprising step (d) detecting tissue motion.

40. The method of claim 33 wherein step (a) comprises transmitting the ultrasonic acoustic energy from a plurality of elements, each of the plurality of elements spaced at least one wavelength from other ones of the plurality of elements.

41. The method of claim 33 wherein step (a) comprises transmitting from a transducer selected from the group consisting of intra-vascular and intra-cardiac.

42. The method of claim 33 where step (c) comprises processing selected from the group consisting of:

applying a wall filter to detect contrast agents, triggering to detect contrast agents and combinations thereof.

43. An ultrasound system for generating contrast images from within a body, the system comprising:

a catheter transducer comprising a linear array of elements for transmitting ultrasonic acoustic energy and for receiving reflected energy responsive to the transmitted ultrasonic acoustic energy and contrast agents; and

an image processor for generating an image responsive to the reflected energy.

44. The system of claim 43 wherein the image processor is operable to obtain information at a harmonic of the transmitted ultrasonic acoustic energy from the reflected energy and the image is responsive to the information at the harmonic.

45. The system of claim 43 further comprising an estimate of perfusion responsive to the reflected energy.

46. The system of claim 43 further comprising a means for triggering transmission of the ultrasonic acoustic energy.

47. The system of claim 43 further comprising:

a beamformer operatively connected between the catheter transducer and the image processor; and

a beamformer controller operative to cause a first transmission of the ultrasonic acoustic energy at a first power level and to cause a second transmission of the ultrasonic acoustic energy at a second power level that is less than the first power level.

48. The system of claim 43 further comprising an estimate of an area responsive to the reflected energy.

49. The system of claim 43 further comprising:

a beamformer operatively connected between the catheter transducer and the image processor;

a beamformer controller operative to cause a first transmission of the ultrasonic acoustic energy at a first phase and to cause a second transmission of the ultrasonic acoustic energy at a second phase that is shifted from the first phase;

wherein the image processor is operable to combine reflected energy responsive to the first phase with reflective energy responsive to the second phase; and

wherein the image is responsive to the result of the combination.

50. The system of claim 43 wherein the image processor comprises a Doppler processor for generating tissue motion information.

51. The system of claim 43 wherein the catheter transducer comprises a plurality of elements, each of the plurality of elements spaced at least one wavelength from other ones of the plurality of elements.

52. The system of claim 43 wherein the catheter transducer comprises a transducer selected from the group consisting of:

intra-vascular and intra-cardiac.

53. The system of claim 43 where the image processor comprises a Doppler processor and wall filter.