Contrast-agent enhanced color-flow imaging

• US 6,638,228 B1
• Filed: 04/26/2002
• Issued: 10/28/2003
• Est. Priority Date: 04/26/2002
• 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.)
• Inventors: Perry, Jodi L. T., Rafter, Patrick G., Brock-Fisher, George A., Poland, Mckee Dunn
• Primary Examiner(s): Jaworski, Francis J.
• Assistant Examiner(s): PATEL, MAULIN M
• Application Number:
  US10/134,164
• Publication Number:
  US 20030204142A1
• Time in Patent Office: 550 Days
• Field of Search: 600/443, 600/447, 600/455, 600/454, 600/448, 600/449, 600/437
• US Class Current: 600/443
• 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: 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: G01S 15/102 using transmission of pulses having some particular characteristics
• 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 7/52038 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

Abstract

Systems and methods for enhanced color-flow imaging of contrast-agent perfused blood vessels and other tissues within a patient'"'"'s body are disclosed. The method generally comprises, introducing one or more contrast agents into the body, power-modulating transmit pulses into the body, receiving echoes from the body, processing the received echoes to reduce tissue-generated echoes and echoes from stationary contrast agent, using a color-flow processor to generate a color-encoded display responsive to contrast-agent motion. The method may be implemented by a system with a an excitation-signal source, a transducer, an ultrasound-processing system having multiple image processors including a color-flow processor, as well as, a clutter filter, and an arbiter, and a display-processing system.

Claims

1. A method for imaging contrast agents, comprising:

transmitting power-modulated ultrasonic pulses comprising a predetermined transmit sequence having a plurality of transmit lines into a patient'"'"'s body;

receiving a plurality of ultrasonic echoes comprising contrast-agent generated echoes and tissue-generated echoes from the patient'"'"'s body;

processing the received ultrasonic echoes to generate a plurality of ultrasonic-echo signals responsive to both the contrast-agent generated and tissue-generated echoes;

processing the plurality of ultrasonic-echo signals to suppress tissue-generated echoes;

processing the plurality of ultrasonic-echo signals to suppress stationary contrast-agent generated echoes;

applying the plurality of contrast-agent generated echo signals to a color-flow algorithm to generate a plurality of data points responsive to contrast-agent motion; and

displaying the plurality of data points over time.

2. The method of claim 1, wherein processing to suppress tissue generated signals comprises applying a finite-impulse-response (FIR) filter to the received ultrasonic echoes.

3. The method of claim 1, wherein processing to suppress stationary contrast-agent generated echoes comprises applying a two-stage clutter filter to the received ultrasonic echoes.

4. The method of claim 1, wherein the plurality of data points responsive to contrast-agent motion contain information related to direction of motion and relative velocity.

5. The method of claim 1, wherein the plurality of transmit lines are generated with transmit signals having different voltage amplitudes.

6. The method of claim 1, wherein the plurality of transmit lines are generated with transmit signals having different phases.

7. The method of claim 1, wherein the plurality of transmit lines are generated with transmit signals having different polarities.

8. The method of claim 1, wherein the plurality of data points responsive to contrast-agent motion contain information related to direction of motion and relative velocity.

9. The method of claim 2, wherein a plurality of first coefficients are applied to the received ultrasonic echoes.

10. The method of claim 4, wherein displaying is performed after a determination that the intensity of the velocity information exceeds a threshold.

11. The method of claim 4, wherein displaying is performed after correcting the velocity information for tissue motion.

12. The method of claim 9, wherein a plurality of second coefficients are applied to the received ultrasonic echoes.

13. The method of claim 10, wherein B-mode image data is displayed after a determination that the intensity of the velocity information fails to meet the threshold.

14. An improved ultrasound-imaging system, comprising:

an excitation-signal source configured to generate a power-modulated transmit-line sequence;

a transducer coupled to the excitation-signal source, the transducer configured to emit a plurality of ultrasonic-pulses responsive to the power-modulated transmit-line sequence into a medium and to convert a plurality of received ultrasonic echoes responsive to both tissue and one or more contrast agents within the medium to a plurality of echo signals;

an ultrasound-processing system coupled to the transducer, the ultrasound-processing system configured to reduce tissue-generated ultrasonic-echo signals and reduce stationary contrast-agent generated ultrasonic-echo signals, while passing ultrasonic-echo signals generated from moving contrast agent; and

a display-processing system coupled to the ultrasound-processing system, the display-processing system configured to receive and generate a graphic representation responsive to the ultrasonic-echo signals generated from moving contrast agent.

15. The system of claim 14, wherein the power-modulated transmit-line sequence is generated with transmit signals having different voltage amplitudes.

16. The system of claim 14, wherein the power-modulated transmit-line sequence is generated with transmit signals having different polarities.

17. The system of claim 14, wherein the power-modulated transmit-line sequence is generated with transmit signals having different phases.

18. The system of claim 14, wherein the ultrasound-processing system comprises a clutter filter.

19. The system of claim 18, wherein the ultrasound-processing system comprises a plurality of two-dimensional imaging processors.

20. The system of claim 19, wherein the ultrasound-processing system comprises a color-flow processor.

21. The system of claim 18, wherein the clutter filter comprises a multiple sample one-zero filter.

22. The system of claim 21, wherein the clutter filter time shifts the zero between adjacent ultrasonic-echo signal samples.

23. The system of claim 22, further comprising:

a tissue-velocity processor coupled to the ultrasound-processing system, the tissue-velocity processor configured to generate a first output signal responsive to motion of tissue-generated ultrasonic-echo signals;

an arbiter coupled to a second output signal from the color-flow processor and a third output signal from at least one of the plurality of two-dimensional image processors, the arbiter configured to forward the second output signal from the color-flow processor when the intensity of the second output signal exceeds a threshold; and

an arithmetic junction coupled to an output of the arbiter and the first output signal, the arithmetic junction configured to perform a subtraction of the first output signal from the second output signal.

24. The system of claim 23, wherein the arbiter is configured to forward the third output signal from at least one of the plurality of two-dimensional image processors when the intensity of the second output signal fails to exceed a threshold.