Two pulse technique for ultrasonic harmonic imaging

• US 5,951,478 A
• Filed: 12/08/1997
• Issued: 09/14/1999
• Est. Priority Date: 10/10/1995
• Status: Expired due to Term

• Current Assignee: Advanced Technology Laboratories Inc (Koninklijke Philips N.V.)
• Original Assignee: Advanced Technology Laboratories Inc (Koninklijke Philips N.V.)
• Inventors: Simpson, David Hope, Hwang, Juin-Jet
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US08/986,383
• Time in Patent Office: 645 Days
• Field of Search: 600/437, 600/439, 600/442-443, 600/447, 600/458
• 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 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• 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 8/488 involving Doppler signals
• 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 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 harmonic contrast agents. The harmonic echo effect is detected through alternate polarity acquisition of harmonic contrast agent effects, which provides the benefits of suppressing the harmonic components of the transmitted signal while eliminating clutter.

Claims

1. A method of ultrasonically detecting the harmonic response of a medium inside the body comprising the steps of:

transmitting a first ultrasonic pulse into the body and receiving first ultrasonic echo signals in return;

transmitting a second ultrasonic pulse into the body and receiving second ultrasonic echo signals in return, said second pulse exhibiting a different polarity than said first pulse;

combining said first and second echo signals to detect said harmonic response; and

producing an image of said harmonic response.

2. The method of claim 1, wherein said step of combining comprises summing said first and second echo signals.

3. A method of ultrasonically detecting the nonlinear response of a medium inside the body comprising the steps of:

transmitting a first ultrasonic pulse into the body to generate a first nonlinear response signal;

transmitting a second ultrasonic pulse into the body to generate a second nonlinear response signal, said second pulse exhibiting a different phase than said first pulse;

combining said first and second response signals to extract a nonlinear component; and

producing an image from said nonlinear component.

4. The method of claim 7, wherein said step of combining comprises summing said first and second response signals.

5. The method of claim 7, wherein said step of combining comprises integrating said first and second response signals.

6. The method of claim 3, wherein said step of combining simultaneously diminishes a primary component.

7. The method of claim 3, wherein said step of transmitting a second pulse transmits a second pulse of opposite phase to said first pulse.

8. A method of ultrasonically detecting the nonlinear response of an acoustic medium within the body comprising the steps of:

transmitting a first ultrasonic signal to said medium to elicit a first echo waveform;

transmitting a second ultrasonic signal of a different polarity than said first ultrasonic pulse to said medium to elicit a second echo waveform;

detecting said first and second echo waveforms; and

combining said first and second echo waveforms to detect a nonlinear response of said medium.

9. The method of claim 8, wherein said step of transmitting a second ultrasonic signal transmits a second ultrasonic signal of opposite phase to said first signal.

10. The method of claim 8, further comprising the stop of producing an image using said detected nonlinear response of said medium.

11. A method of detecting the acoustic properties of substances inside the body which return primary and nonlinear components comprising the steps of:

transmitting a first ultrasonic signal of the form p_i1 =p cos ω

t into the body and detecting a backscattered pressure wave of the form p_B1 (ω

,t)=k₁ (ω

,t)p+k₂ (ω

,t)p² ;

transmitting a second ultrasonic signal of the form p_i2 =-p cos ω

t into the body and detecting a backscattered pressure wave of the form p_B2 (ω

,t+δ

t)=-k₁ (ω

,t+δ

t)p+k₂ (ω

,t+δ

t)p² ;

combining the two backscattered pressure waves to cancel components of the two detected pressure waves; and

producing an image using the combined backscattered pressure waves.

12. The method of claim 11, wherein said step of combining comprises summing said detected backscattered pressure waves.

13. The method of claim 12, wherein said step of combining produces a total backscattered pressure magnitude of the form

14. The method of claim 11, wherein said step of combining diminishes a primary component of said detected pressure waves.