Automated power level for contrast agent imaging

• US 20060064018A1
• Filed: 09/17/2004
• Published: 03/23/2006
• Est. Priority Date: 09/17/2004
• Status: Active Grant

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Chomas, James E.
• Granted Patent: US 8,043,219 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• CPC Class Codes: A61B 8/14 Echo-tomography
• 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

Abstract

Automated determination and setting of an ultrasound system transmit power level is provided for contrast agent imaging. Low mechanical index imaging of contrast agents allows substantially continuous imaging of contrast agents without destruction. By comparing data associated with different transmit power levels and spatial locations, different delays between acquisition or different acquisition sequences, a contrast agent imaging transmit power generally minimizing destruction of contrast agents and maximizing signal-to-noise ratio is automatically determined. By using contrast agent specificity for setting the transmit power in addition or alternative to destruction of contrast agents, harmonic imaging may be improved.

Claims

1. A method for setting a transmit power level to image contrast agents, the method comprising:

(a) acquiring first and second data from first and second scan lines, respectively, in a scan region, the first and second data responsive to first and second transmit powers, respectively, the first transmit power different than the second transmit power and the first scan line different than the second scan line;

(b) comparing the first data with the second data; and

(c) setting a third transmit power in response to the comparison for contrast agent imaging.

2. The method of claim 1 wherein (c) comprises setting the third transmit power to less than the greater of the first and second transmit powers.

3. The method of claim 1 further comprising:

(d) acquiring third data from a third transmit line different than the first and second transmit lines, the third data responsive to a fourth transmit power, the fourth transmit power less than the first and second transmit powers;

wherein (b) comprises comparing the first, second and third data.

4. The method of claim 1 wherein (a) comprises acquiring the first and second data from a same frame of data at a substantially same time.

5. The method of claim 1 wherein (a) comprises acquiring a frame of data with at least the first and second transmit powers interleaved as a function of scan line position.

6. The method of claim 5 wherein the first data corresponds to scan lines including the first scan line associated with the first transmit power and the second data corresponds to scan lines including the second scan line associated with the second transmit power;

wherein (b) comprises;

(b1) dividing the first data by regions;

(b2) dividing the second data by the regions;

(b3) determining first and second numbers of bubble destruction events within each of the regions for the first and second data, respectively; and

(b4) comparing a pattern of the first and second numbers as a function of region.

7. The method of claim 1 further comprising:

(d) detecting the first and second data as a function of a loss of correlation.

8. The method of claim 1 further comprising:

(d) detecting the first and second data as a function of contrast agent specificity;

wherein (b) comprises identifying a maximum specificity of the first and second data; and

wherein (c) comprises setting the third transmit power as a function of the one of the first or second transmit powers associated with the maximum specificity.

9. The method of claim 1 wherein (a) and (b) comprise power level determination acts and (c) comprises setting the transmit power for medical diagnostic imaging.

30. The method of claim 1 wherein (a) comprises acquiring a first frame of data with the first transmit power followed by a second frame of data with the second transmit power, the first data being from the first frame of data and the second data being from the second frame of data.

31. The method of claim 30 wherein (a) comprises acquiring the first frame of data with scan lines that are different than scan lines for the second frame of data.

10. A method for setting a transmit power level to image contrast agents, the method comprising:

(a) interleaving different transmit powers as a f unction of scan line within a scanned region;

(b) detecting destruction of contrast agents in response to one of the different transmit powers; and

(c) automatically setting a contrast agent imaging transmit power level equal to or less than the one of the different transmit powers associated with destruction of contrast agents.

11. The method of claim 10 wherein (a) comprises transmitting with the different transmit powers for a same frame of data at a substantially same time.

12. An ultrasound system for setting a transmit power level to image contrast agents, the system comprising:

a transducer;

a transmit amplifier connected with the transducer; and

a processor operable to set an contrast agent imaging transmit power of the transmit amplifier, the contrast agent imaging transmit power set as a function of a comparison of first and second data acquired in response to scan line interleaving of first and second transmit powers, respectively.

13. The ultrasound system of claim 12 wherein the contrast agent imaging transmit power is set to less than a greater of the second and first transmit powers.

14. The ultrasound system of claim 12 further comprising:

a loss of correlation detector wherein the first and second data comprise detected data.

15. The ultrasound system of claim 12 wherein the processor is operable to determine first and second specificities for the first and second data, respectively, the contrast agent imaging transmit power being set as a function of a greater one of the first and second specificities.

16. A method for setting a transmit power level to image contrast agents, the method comprising:

(a) determining a first relationship of contrast agent signal to tissue signal associated with a first transmit power;

(b) determining a second relationship of contrast agent signal to tissue signal associated with a second transmit power, the second transmit power different than the first transmit power;

(c) comparing the first and second relationships; and

(d) setting a contrast agent imaging transmit power in response to the comparison.

17. The method of claim 16 wherein (a) and (b) comprise detecting the first and second relationships as a function of contrast agent specificity;

18. The method of claim 16 wherein (a) and (b) comprise determining first and second ratios of contrast agent signals to tissue signals associated with the first and second transmit powers, respectively, wherein (c) comprises identifying a maximum of the first and second ratios, and wherein (d) comprises setting the contrast agent imaging transmit power as a function of one of the first or second transmit powers associated with the maximum.

19. The method of claim 18 wherein (d) comprises setting as a function of the one associated with the maximum and different than the other of the first and second transmit powers.

20. The method of claim 16 further comprising:

(d) determining a third relationship associated with a third transmit power, the third transmit power different than the first and second transmit powers;

wherein (c) comprises comparing the first, second and third relationships.

21. The method of claim 16 further comprising:

(e) transmitting at a fundamental frequency band; and

(f) receiving information at a harmonic of the fundamental frequency band in response to (e);

wherein (a) and (b) comprise determining the first and second relationships as a function of the information received at the harmonic.

22. The method of claim 21 wherein (e) comprises transmitting a plurality of pulses, and wherein (f) comprises receiving information in response to the plurality of pulses;

further comprising;

(g) combining the received information, the combined information being contrast agent signal, wherein received information free of combination is the tissue signal.

23. The method of claim 16 further comprising:

(e) acquiring first and second data from first and second scan lines, respectively, in a scan region, the first and second data responsive to the first and second transmit powers, respectively, the first scan line different than the second scan line;

wherein (a) and (b) comprise determining the first and second relationships as a function of the first and second data, respectively.

24. The method of claim 16 wherein (a), (b) and (c) comprise power level determination acts and (d) comprises setting the contrast agent imaging transmit power for medical diagnostic imaging.

25. A method for setting a transmit power level to image contrast agents, the method comprising:

(a) detecting first and second data as a function of contrast agent specificity in response to first and second transmit powers, respectively;

(b) identifying a maximum specificity of the first and second data

(c) automatically setting a contrast agent imaging transmit power level as a function of a one of the first or second transmit powers associated with the maximum specificity.

26. The method of claim 25 wherein (a) comprises detecting as a function of harmonic information of a fundamental transmit band.

27. An ultrasound system for setting a transmit power level to image contrast agents, the system comprising:

a transducer;

a transmit amplifier connected with the transducer; and

a processor operable to set an contrast agent imaging transmit power of the transmit amplifier, the contrast agent imaging transmit power set as a function of a comparison of first and second relationships of contrast agent signal with tissue signal in response to first and second transmit powers, respectively.

28. The ultrasound system of claim 27 wherein the contrast agent imaging transmit power is set to the one of the first and second transmit powers associated with a highest ratio of the contrast agent signal to the tissue signal.

29. The ultrasound system of claim 27 wherein the processor is operable to determine first and second specificities for the first and second data, respectively, the contrast agent imaging transmit power being set as a f unction of a greater one of the first and second specificities.