METHODS FOR ACQUISITION AND DISPLAY IN ULTRASOUND IMAGING

• US 20110144494A1
• Filed: 09/18/2009
• Published: 06/16/2011
• Est. Priority Date: 09/18/2008
• Status: Abandoned Application

• Current Assignee: VisualSonics Inc. (Fujifilm Holdings Corporation)
• Original Assignee: VisualSonics Inc. (Fujifilm Holdings Corporation)
• Inventors: Wen, Jerrold, White, Christopher A., Hirson, Desmond, Needles, Andrew, Liu, Kai Wen, Mehi, James
• Application Number:
  US12/562,935
• Publication Number:
  US 20110144494A1
• Time in Patent Office: Days
• US Class Current: 600/441
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61B 8/14 Echo-tomography
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: H10N 30/06 Forming electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor

Abstract

In general, the invention provides methods for use in the acquisition and display of ultrasound images. In particular, the invention provides methods for displaying ultrasound images using a persistence algorithm, gating ultrasound acquisition based on subject respiration, triggering ultrasound acquisition based on subject ECG, and destroying bubble contrast agents during imaging. The methods may be employed with any suitable ultrasound system.

Claims

1. A method for frame persistence implemented by an ultrasound imaging system, comprising:

a. obtaining a plurality of frames of ultrasound at a baseline frame rate (FR₀);

b. processing a portion of the plurality of frames of ultrasound at a processing rate (PR), wherein the portion comprises a first frame comprising a first plurality of data points;

c. applying a persistence routine to at least one of the first plurality of data points, wherein the persistence routine combines the at least one of the first plurality of data points with a corresponding stored data point based on a user defined persistence setting, FR₀, and PR, to produce at least one persistence processed data point;

d. storing the at least one persistence processed data point to replace the stored data point of (c); and

e. generating a persistence processed output frame from the at least one persistence processed data point.

2. The method of claim 1, wherein the persistent routine comprises:

y(n)=(1−

(1−

α

)^p)·

x(n)+(1−

α

)^p·

y(n−

1),

where p is the ratio FR₀/PR, α

is the user defined persistence setting and is greater than 0 and less than 1, n is the frame index, y(n) is the persistence processed data point, x(n) is the at least one of the first plurality of data points, and y(n−

1) is the corresponding stored data point, wherein the value of y(n−

1) is set to 0 for n=1.

3. The method of claim 1, wherein the plurality of frames comprises B-Mode data, Color Flow image data, or Power Doppler image data.

4. The method of claim 1, further comprising displaying the persistence processed output frame on a display.

5. The method claim 1, further comprising repeated steps (c)-(e) with subsequent frames.

6. A method for destroying contrast agent bubbles present in a region of interest of a subject, comprising:

(a) providing the subject to which has been administered contrast agent bubbles;

(b) scanning the region of interest in the subject with ultrasound;

(c) receiving a bubble destruction command;

(d) transmitting at least one ultrasound pulse into the region of interest, wherein the ultrasound pulse is transmitted at a mechanical index sufficient to destroy bubbles in the region of interest; and

(e) resuming scanning of the region of interest.

7. The method of claim 6, wherein the region of interest comprises one or more focal zones, and the ultrasound pulse of step (d) is transmitted into each focal zone.

8. The method of claim 6, wherein the mechanical index of step (c) is greater than about 0.6.

9. The method of claim 6, wherein step (d) comprises operating at 10-20 MHz with a 4 cycle pulse, with a plurality of focal zones evenly spaced over a depth of the region of interest (ROI), at 100% TX power at a mechanical index (MI) greater than 0.6, wherein 10-20 MHz pulses are fired at a Pulse Repetition Frequency (PRF) of 25 kHz and above for up to 1 s.

10. The method of claim 6, wherein scanning of the region of interest is discontinued between steps (b) and (c).

11. The method of claim 6, wherein ultrasound employed in steps (b) and (e) has a wider bandwidth than ultrasound employed in step (d).

12. The method of claim 6, wherein the ultrasound employed in steps (b) and (e) is produced by one transducer, and the ultrasound transmitted in step (d) is produced by a different transducer.

13. The method of claim 6, wherein a single transducer is employed in steps (b), (d), and (e).

14. The method of claim 6, wherein step (e) comprises monitoring for reperfusion of bubble contrast agent into the region of interest.

15. The method of claim 6, wherein step (e) comprises monitoring for determining the circulating amount of bubble contrast agent.

16. A method for respiration gating during ultrasound imaging, comprising:

acquiring a respiration signal from a subject;

determining a start of a respiration cycle in the respiration signal;

setting a valid zone based on the start of the respiration cycle and user defined offset and/or duration;

acquiring a plurality of frames of ultrasound;

discarding one or more frames of the plurality of frames acquired outside the valid zone; and

outputting remaining frames of the plurality of frames acquired inside the valid zone.

17. The method of claim 16, wherein acquiring a plurality of frames comprises acquiring the plurality of frames at an acquisition rate of at least 200 frames per second.

18. The method of claim 16, wherein each of the acquired plurality of frames are time-stamped to indicate when each frame is acquired.

19. A method for ECG triggered acquisition during ultrasound imaging, comprising:

(a) acquiring, at a host computer, an ECG signal from a subject;

(b) determining, at the host computer, an R-wave point in the ECG signal;

(c) determining, at the host computer, a trigger point threshold and a trigger slope based on the R-wave point;

(d) transferring the trigger point threshold and the trigger slope to a programmable logic device; and

(e) triggering, by the programmable logic device, the acquisition of ultrasound based on the trigger point threshold and the trigger slope.

20. The method of claim 19, wherein triggering based on the trigger point threshold and the trigger slope is used to acquire a cineloop that starts at a specified point in a cardiac cycle and runs for a specified number of cardiac cycles.

21. The method of claim 19, wherein triggering based on the trigger point threshold and the trigger slope is used to acquire one or more of B-Mode data, Color Doppler Mode data, Power Doppler Mode data, Contrast Mode data, and 3D Mode data.

22. The method of claim 19, further comprising:

(i) acquiring a respiration signal from a subject;

(ii) determining a start of a respiration cycle in the respiration signal;

(iii) setting a valid zone based on the start of the respiration cycle and user defined offset and/or duration;

(iv) discarding ultrasound acquired outside the valid zone during step (e); and

(v) outputting ultrasound acquired inside the valid zone during step (e).

23. The method of claim 22, wherein ultrasound is acquired at a rate of at least 200 frames per second.

24. The method of claim 22, wherein ultrasound frames are time-stamped to indicate when each frame is acquired.