METHODS AND SYSTEMS FOR COLOR FLOW DYNAMIC FRAME PERSISTENCE

• US 20110164794A1
• Filed: 12/03/2010
• Published: 07/07/2011
• Est. Priority Date: 01/05/2010
• Status: Active Grant

• Current Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Original Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Inventors: Zou, Yaoxian, Yao, Bin, Hu, Qinjun
• Granted Patent: US 8,542,895 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• 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 8/5215 involving processing of medical diagnostic data
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Methods and systems for color flow dynamic frame persistence in ultrasonic imaging are provided.

Claims

1. A method for calculating blood vessel direction of a flow velocity image comprising a plurality of points, the method comprising:

distinguishing each of the points in the flow velocity image as points in a flow region and points in a background region;

estimating a rough direction of a computing point by setting a plurality of directions and respectively calculating the number of points in the flow region connecting with the computing point in each direction, and taking the direction with the maximum number of points as the rough direction of the computing point;

determining midpoints on the direction vertical to the rough direction in a neighborhood, and taking a line connecting the midpoints as a median line of the blood vessel in the neighborhood, wherein the neighborhood is centered on the computing point and includes a plurality of points in the flow region on the rough direction; and

calculating the direction of the blood vessel on the computing point according to the determined median line of the blood vessel.

2. The method of claim 1, wherein distinguishing comprises binarizing the image by marking the points whose values are smaller than a predefined threshold as zero and the remaining points as one, thereby distinguishing the points in the flow region and the points in the background region.

3. The method of claim 1, wherein calculating comprises applying linear fitting or Hough Transform to the determined median line of the blood vessel.

4. The method of claim 1 wherein the plurality of directions is selected from the group consisting of two directions, or four directions, or eight directions.

5. The method of claim 4, wherein the plurality of directions is selected from a set of directions comprising horizontal and vertical directions, and a set of directions comprising 0°

, 45°

, 90° and

135°

.

6. A method for calculating blood vessel direction of a flow velocity image comprising a plurality of points, the method comprising:

distinguishing each of the points in the flow velocity image as points in a flow region and points in a background region;

extracting a skeleton of the flow region from the distinguished image; and

calculating a direction of each point of the skeleton according to a plurality of neighbor points of each computing point of the skeleton.

7. The method of claim 6, wherein the direction of at least one point of the skeleton is regarded as the direction of points not on the skeleton, wherein the point of the skeleton is nearest to the points not on the skeleton and can be lined up in the flow region in the distinguished image.

8. The method of claim 6, wherein calculating comprises applying linear fitting or Hough Transform to a plurality of neighbor points of the skeleton of each computing point of the skeleton so as to calculate the direction of each point of the skeleton.

9. The method of claim 6, wherein the extraction step further comprises deburring the extracted skeleton.

10. A method for color flow dynamic frame persistence, comprising:

acquiring a result of a previous frame persistence and a current flow velocity image;

calculating a blood vessel direction reflected by the result of the previous frame persistence;

offsetting the result of previous frame persistence along the blood vessel direction with flow direction and flow velocity; and

performing frame persistence between the current flow velocity image and the offset result of the previous frame persistence.

11. The method of claim 10, further comprising:

interpolating the points which have no value in the offset velocity image.

12. The method of claim 10, wherein calculating comprises calculating the blood vessel direction with gradient properties.

13. The method of claim 10, wherein offsetting is performed such that the larger the velocity of flow, the larger the offset, or the smaller the velocity of flow, the smaller the offset.

14. The method of claim 10 wherein offsetting comprises decomposing the offset of a point in the velocity image along the horizontal and vertical direction respectively, and offsetting the point along the flow direction with a horizontal offset and vertical offset.

15. A system for calculating blood vessel direction of a flow velocity image comprising a plurality of points, the system comprising:

a distinguishing module configured to distinguish each of the points in the blood flow velocity image as points in a flow region and points in a background region;

an estimation module configured to set a plurality of directions and respectively calculate the number of the points in the flow region connecting with the computing point in each direction, and take the direction with the maximum number as the rough direction of the computing point;

a determination module configured to determine midpoints on the direction vertical to the rough direction in a neighborhood, and take the line connecting the midpoints as the median line of the blood vessel in the neighborhood, wherein the neighborhood takes the computing point as center and comprises a plurality of points in the flow region on the rough direction; and

a computation module configured to calculate the direction of the blood vessel on the computing point according to the determined median line of the blood vessel.

16. The system of claim 15, wherein the first distinguishing module is configured to binarize the by marking the points whose values are smaller than a predefined threshold as zero and the remaining points as 1, thereby distinguishing the points in the flow region and the points in the background region.

17. The system of claim 15 wherein the plurality of directions comprising two directions, or four directions, or eight directions.

18. A system for calculating blood vessel direction of a flow velocity image comprising a plurality of points, comprising:

a distinguishing module configured to distinguish each of the points in the flow velocity image as points in a flow region and points in a background region;

an extraction module configured to extract a skeleton of the flow region from the distinguished image; and

a computation module configured to calculate the direction of each point of the skeleton according to a plurality of neighbor points of each computing point of the skeleton.

19. The system of claim 18, wherein the direction of at least one point of the skeleton is regarded as the direction of points not on the skeleton, wherein the point of the skeleton is nearest to the points not on the skeleton and can be lined up in the flow region in the distinguished image.

20. A system for color flow dynamic frame persistence, comprising:

an acquisition module configured to acquire a result of a previous frame persistence and current flow velocity image;

a computation module configured to calculate a blood vessel direction reflected by the result of the previous frame persistence;

an offset module configured to offset the result of previous frame persistence along the direction of a blood vessel with flow direction and flow velocity; and

a persistence module configured to implement frame persistence between the current flow velocity image and the offset result of the previous frame persistence.

21. The system of claim 20, further comprising:

an interpolation module configured to interpolate points which have no value in the offset velocity image.

22. The system of claim 20, wherein the computation module calculates the blood vessel direction with gradient properties.

23. The system of claim 20 wherein the offset step comprises decomposing the offset of a point in the velocity image along the horizontal and vertical directions respectively, offsetting the point along the flow direction with a horizontal offset and vertical offset.

24. A computer-readable medium comprising program code that causes a processor to perform a method for calculating blood vessel direction of a flow velocity image comprising a plurality of points, the method comprising:

distinguishing each of the points in the flow velocity image as points in a flow region and points in a background region;

estimating a rough direction of a computing point by setting a plurality of directions and respectively calculating the number of points in the flow region connecting with the computing point in each direction, and taking the direction with the maximum number of points as the rough direction of the computing point;

determining midpoints on the direction vertical to the rough direction in a neighborhood, and taking a line connecting the midpoints as a median line of the blood vessel in the neighborhood, wherein the neighborhood is centered around the computing point and includes a plurality of points in the flow region on the rough direction; and

calculating the direction of the blood vessel on the computing point according to the determined median line of the blood vessel.