Method and apparatus for generating large compound ultrasound image

• US 5,575,286 A
• Filed: 03/31/1995
• Issued: 11/19/1996
• Est. Priority Date: 03/31/1995
• Status: Expired due to Term

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Systems, Inc. (Siemens AG)
• Inventors: Weng, Lee, Tirumalai, Arun P.
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US08/414,978
• Time in Patent Office: 599 Days
• Field of Search: 128/653.1, 128/653.2, 128/654, 128/659, 128/660.01, 128/660.07, 128/660.08
• US Class Current: 600/444
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/0866 involving foetal diagnosis; pre-natal or peri-natal diagnosis of the baby
• 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 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: G01S 15/52 Discriminating between fixed and moving objects or between objects moving at different speeds
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/5206 Two-dimensional coordinated display of distance and direction; B-scan display
• CPC Class Codes: G01S 7/52068 Stereoscopic displays; Three-dimensional displays; Pseudo 3D displays G01S15/8993 takes precedence
• CPC Class Codes: G01S 7/52073 Production of cursor lines, markers or indicia by electronic means
• CPC Class Codes: G01S 7/52074 Composite displays, e.g. split-screen displays; Combination of multiple images or of images and alphanumeric tabular information
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10068 Endoscopic image
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 7/223 using block-matching
• CPC Class Codes: G06T 7/238 using non-full search, e.g. three-step search
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments

Abstract

An image registration method and apparatus is provided in which consecutive ultrasonic image frames are correlated in order to derive transducer motion information. Since ultrasonic images from real-time scanning operations are highly correlated from one frame to another, the individual images can be divided into several smaller sub-image regions and a very fast and robust image motion detection algorithm utilized to measure the sub-image motion. This algorithm uses a fast adaptive coarse/fine minimum-sum-absolute-difference (MSAD) search strategy to compute an initial estimation of the local motion vectors. The initial estimation is combined with two measurement parameters by use of a fuzzy logic technique to derive a final estimation of the local motion vectors. The final local motion vectors are applied to a least-squares (L-S) process in order to estimate global image motion. Finally, a fast display technique generates compound images based on the derived global image motion.

Claims

1. A method for providing a compound image, comprising the steps of:

generating a plurality of substantially adjacent image frames of an interrogation region of a patient'"'"'s body;

dividing individual ones of the image frames into a plurality of sub-image regions;

estimating local motion vectors of the respective sub-image regions between consecutive ones of the image frames;

estimating global image motion based on the estimated local motion vectors; and

displaying a compound image based on the estimated global image motion.

2. The method of claim 1, wherein the step of dividing the individual image frames into a plurality of sub-image regions further comprises the step of dividing the individual image frames into a range of approximately eight to twenty sub-image regions.

3. The method of claim 1, wherein the estimating steps are performed concurrently with the generating step so that a real-time compound image is provided in the displaying step.

4. A method for providing a compound image from a plurality of individual image frames, comprising the steps of:

dividing the individual image frames into a plurality of sub-image regions;

estimating local motion vectors of the respective sub-image regions between consecutive ones of the individual image frames;

estimating global image motion based on the estimated local motion vectors; and

displaying a compound image based on the estimated global image motion;

wherein the step of estimating local motion vectors further comprises the steps of;

calculating an initial estimation of the local motion vectors using a fast adaptive coarse/fine minimum-sum-absolute-difference (MSAD) search; and

deriving a final estimation of the local motion vectors from the initial estimation of the local motion vectors by use of a fuzzy logic technique.

5. The method of claim 4, wherein the step of deriving a final estimation further comprises the step of defining a first quality factor of the MSAD by measuring the difference between the value of MSAD and mean sum-absolute-difference (SAD).

6. The method of claim 5, wherein the step of deriving a final estimation further comprises the step of defining a second quality factor of MSAD by measuring deviation of the initial estimation of the local motion vector from an historical measurement of the local motion vector.

7. The method of claim 6, wherein the step of deriving a final estimation further comprises the step of defining membership functions for the first and second quality factors.

8. The method of claim 7, wherein the step of deriving a final estimation further comprises the step of determining a membership value for the first and second quality factors.

9. The method of claim 8, wherein the step of deriving a final estimation further comprises the step of combining the membership values for the first and second quality factors in accordance with predefined fuzzy rules to generate an output value.

10. The method of claim 9, wherein the step of deriving a final estimation further comprises the step of averaging the initial estimation of the local motion vectors with the historical estimation of the local motion vectors using the output value as a weight.

11. The method of claim 4, wherein the step of calculating an initial estimation of the local motion vectors further comprises the steps of conducting a one-dimensional search in a first axial direction and at least one additional one-dimensional search in a second axial direction perpendicular to said first axial direction.

12. The method of claim 4, wherein the step of calculating an initial estimation of the local motion vectors further comprises the steps of defining a search region having an area greater than an associated one of the sub-image regions, the one-dimensional searches being conducted within the search region.

13. A method for providing a compound image from a plurality of individual image frames, comprising the steps of:

dividing the individual image frames into a plurality of sub-image regions;

estimating local motion vectors of the respective sub-image regions between consecutive ones of the individual image frames;

estimating global image motion based on the estimated local motion vectors; and

displaying a compound image based on the estimated global image motion;

wherein the step of estimating global image motion further comprises the step of applying the estimated local motion vectors to a least-squares (L-S) process.

14. An apparatus for providing a compound image, comprising:

an ultrasonic scanner providing a plurality of individual ultrasonic image frames;

means for dividing the individual image frames into a plurality of sub-image regions;

means for estimating local motion vectors of the respective sub-image regions between consecutive ones of the individual image frames by use of a minimum-sum-absolute-difference search;

means for estimating global image motion based on the estimated local motion vectors; and

means for displaying a compound image based on the estimated global image motion.

15. The apparatus of claim 14, wherein the means for estimating local motion vectors further comprises:

means for calculating an initial estimation of the local motion vectors using a fast adaptive coarse/fine minimum-sum-absolute-difference (MSAD) search; and

means for deriving a final estimation of the local motion vectors from the initial estimation of the local motion vectors by use of a fuzzy logic technique.

16. The apparatus of claim 15, wherein the deriving means further comprises means for defining a first quality factor of the MSAD by measuring the difference between the value of MSAD and mean sum-absolute-difference (SAD).

17. The apparatus of claim 16, wherein the deriving means further comprises means for defining a second quality factor of MSAD by measuring deviation of the initial estimation of the local motion vector from an historical measurement of the local motion vector.

18. The apparatus of claim 17, wherein the deriving means further comprises means for defining membership functions for the first and second quality factors.

19. The apparatus of claim 18, wherein the deriving means further comprises means for determining a membership value for the first and second quality factors.

20. The apparatus of claim 19, wherein the deriving means further comprises means for combining the membership values for the first and second quality factors in accordance with predefined fuzzy rules to generate an output value.

21. The apparatus of claim 20, wherein the deriving means further comprises means for averaging the initial estimation of the local motion vectors with the historical estimation of the local motion vectors using the output value as a weight.

22. An apparatus for providing a compound ultrasonic image, comprising:

an ultrasonic scanner providing a plurality of substantially adjacent ultrasonic image frames, said image frames each respectively having a plurality of sub-image regions;

means for estimating local motion of the respective sub-image regions between consecutive ones of the image frames by calculating an initial estimation of the local motion and deriving a final estimation of the local motion from the initial estimation;

means for estimating global image motion based on the estimated local motion; and

means for displaying a compound image based on the estimated global image motion.

23. The apparatus of claim 22, wherein said means for estimating local image motion further comprises a fast adaptive coarse/fine minimum-sum-absolute-difference (MSAD) search.

24. The apparatus of claim 22, wherein both said means for estimating local and global image motion are adapted to operate concurrently with said ultrasonic scanner to permit said displaying means to provide a real-time compound image.