Motion artifact reduction in coherent image formation

• US 20050049496A1
• Filed: 09/03/2003
• Published: 03/03/2005
• Est. Priority Date: 09/03/2003
• Status: Active Grant

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Guracar, Ismayil M.
• Granted Patent: US 7,654,959 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• 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 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00

Abstract

The same analytic data is combined in response to different relative phases. The resulting combinations are detected. The combination associated with the maximum magnitude is then selected for further processing. As a result, the complex data is processed across a variety of possible temporal discontinuities using candidate or possible phase shifts. The phase shift with the least cancellation and the associated combination is selected to minimize motion artifact cancellation.

Claims

1. A method for correcting phase errors in coherent image formation, the method comprising:

(a) applying at least two different relative phases between first and second analytic data received in response to temporally different transmissions; and

(b) selecting associated with one of the at least two different relative phases.

2. The method of claim 1 wherein (a) comprises applying 0 degree, 90 degree, −

90 degree and 180 degree relative phase shifts between the first and second analytic data.

3. The method of claim 1 wherein (b) comprises selecting a combination of the first and second analytic data responsive to the one of the at least two different relative phases.

4. The method of claim 1 further comprising:

(c) azimuthally combining the first and second analytic data in response to a first phase;

(d) azimuthally combining the first and second analytic data in response to a second phase different than the first phase;

(e) detecting first and second magnitudes from the combinations of (c) and (d), respectively;

wherein (b) comprises selecting in response to a largest of the first and second magnitudes.

5. The method of claim 4 further comprising:

(f) low pass filtering the first and second magnitudes as a function of range, wherein (b) comprises selecting one of (c) and (d) in response to the low pass filtered first and second magnitudes.

6. The method of claim 1 further comprising:

(c) acquiring the first and second data in response to first and second respective transmissions separated by about at least 1 millisecond.

7. The method of claim 1 further comprising:

(c) azimuthally combining the first and second analytic data in response to the selected one of the at least two phases, the combination corresponding to at least one of;

(1) synthesizing the first and second analytic data representing a same line, (2) interpolating the first and second analytic data as a line between two lines represented by the first and second data, respectively, (3) interpolating the first and second analytic data as a line different than two lines represented by the first and second data, respectively, and (4) azimuthally filtering across at least two lines represented by the first and second data, respectively.

8. The method of claim 1 further comprising:

(c) applying at least two different relative phases between the second and third analytic data, the third analytic data received in response to a temporally different transmission than the first and second data; and

(d) selecting associated with one of the at least two different relative phases for with the second and third analytic data.

9. The method of claim 1 wherein the first data represents a first receive line spaced in elevation from a second receive line represented by the second data.

10. The method of claim 1 further comprising:

(c) generating a three-dimensional representation responsive to the selection of (b).

11. The method of claim 10 further comprising:

(d) elevationally combining the first and third analytic data in response to the selected one of the at least two phases, the combination corresponding to at least one of;

(1) synthesizing the first and second analytic data representing a same line, (2) interpolating the first and second analytic data as a line between two lines represented by the first and second data, respectively, (3) interpolating the first and second analytic data as a line different than two lines represented by the first and second data, respectively, and (4) azimuthally filtering across at least two lines represented by the first and second data, respectively; and

(e) azimuthally combining analytic data.

12. The method of claim 10 wherein (c) comprises generating the three-dimensional representation responsive to motion compensated analytic interpolation along both elevation and azimuth dimensions, the elevation motion compensated analytic interpolation responsive to the selection of (b).

13. The method of claim 1 wherein (a) comprises inputting the first and second data into a respective at least two complex azimuth filters, both the first and second data input to each of the at least two complex azimuth filters wherein weights of the filters are operable to apply the at least two different relative phases between the first and second data, the at least two complex azimuth filters responsive to different of the at least two different relative phases;

and

wherein (b) comprises selecting as a function of detected outputs of the at least two complex azimuth filters.

14. The method of claim 1 further comprising:

(c) performing (a) and (b) for less than all detected lines of an image.

15. A method for correcting phase errors in coherent image formation, the method comprising:

(a) analytically processing ultrasound data along scan lines spaced in both the azimuth and elevation dimension; and

(b) compensating for motion between at least first and second analytic data for first and second scan lines, respectively, as a function of a relative phase angle, the first and second scan lines spaced along one of;

the elevation dimension and the azimuth dimension.

16. The method of claim 15 wherein (b) comprises:

(b1) applying at least two different relative phases between the first and second analytic data received in response to temporally different transmissions, one of the at least two different relative phases being the relative phase angle; and

(b) selecting associated with one of the at least two different relative phases.

17. The method of claim 15 wherein (a) comprises forming interpolated lines along both the azimuth and elevation dimensions;

further comprising;

(c) generating a three-dimensional representation responsive to (a) and (b).

28. The method of claim 15 wherein (a) comprises forming interpolated lines along the elevation dimension.

18. A method for correcting phase errors in coherent image formation, the method comprising:

(a) filtering without interpolation complex data from at least two acquisitions;

(b) determining a relative phase angle between the complex data of the at least two acquisitions as a function of motion between acquisition of the complex data; and

(c) adjusting (a) as a function of the relative phase angle.

19. The method of claim 18 wherein (a) comprises one of:

(a1) filtering complex data wherein the at least two acquisitions are along a same scan line; and

(a2) filtering complex data wherein the at least two acquisitions are along different scan lines.

20. The method of claim 18 wherein (b) comprises:

(b1) applying at least two different relative phases between the complex data; and

(b2) selecting associated with one of the at least two different relative phases;

wherein (c) comprises selecting one of a plurality of filters, the selected one applying the one of the at least two different relative phases.

21. A system for correcting phase errors in coherent image formation, the system comprising:

a complex filter operable to receive first and second data and operable output third data responsive to a combination of the first and second data with a first relative phase angle and fourth data responsive to a combination of the first and second data with a second relative phase angle, the first relative phase angle different than the second relative phase angle;

a detector operable to detect the third and fourth data; and

a switch operable to select one of the third and fourth data in response to the detector.

22. The system of claim 21 wherein the complex filter comprises a plurality of complex filters each operable to combine the first and second data in response to different relative phase angles.

23. The system of claim 21 wherein the detector comprises a plurality of detectors each operable to detect a respective one of the third and fourth data.

24. The system of claim 21 wherein the switch comprises a multiplexer having inputs connected to outputs of the complex filter, the multiplexer operable to select one of the outputs in response to a comparison of the detected third and fourth data.

25. The system of claim 21 further comprising:

a low pass filter operable to low pass filter outputs of the detector, the switch responsive to the low pass filtered output of the detector.

26. The system of claim 21 further comprising:

a control processor operable to control the complex filter and the switch to output the third data for first and second data acquired sequentially with less than a first temporal separation and operable to control the complex filter and the switch to output one of the third and fourth data in response to the detector for the first and second data acquired sequentially with more than the first temporal separation.

27. The system of claim 21 wherein the complex filter comprises four complex filters each responsive to a different phase angle, wherein the detector comprises four detectors each operable to magnitude detect an output from a respective one of the four complex filters.