Method and Arrangement Relating to X-Ray Imaging

• US 20080212864A1
• Filed: 02/14/2005
• Published: 09/04/2008
• Est. Priority Date: 02/13/2004
• Status: Abandoned Application

• Current Assignee: Sectra Mamea AB (Koninklijke Philips N.V.)
• Original Assignee: Sectra Mamea AB (Koninklijke Philips N.V.)
• Inventors: Bornefalk, Hans
• Application Number:
  US10/597,928
• Publication Number:
  US 20080212864A1
• Time in Patent Office: Days
• US Class Current: 382/132
• CPC Class Codes: G06V 10/50 by performing operations within image blocks; by using histograms, e.g. histogram of oriented gradients [HoG]; by summing image-intensity values; Projection analysis

Abstract

The present invention relates to a method and arrangement for detecting a Region of Interest in an image data set, especially digitalized X-ray image. The method comprises the steps of: extracting phase information from the image data, using said phase information for differentiating between different lines and edges, and skewing said lines towards a centre.

Claims

1. A method of detecting a Region of Interest in an image data set, especially digitalized X-ray image, the method comprising the steps of:

a. extracting phase information from the image data,

b. using said phase information for differentiating between different lines and edges, and

c. skewing said lines towards a centre.

2. The method of claim 1, wherein said step a. comprises extracting an orientation estimate.

3. The method of claim 1, wherein said step b. comprises additional information on a magnitude from a filter answer.

4. The method of claim 1, wherein said region of interest is stellate lesions and said image data is a digitalized mammogram.

5. The method of claim 4 comprising the alternative steps of:

a. obtaining an image data corresponding to said mammogram (901);

b. obtaining an image mask (902);

c. substantially uniformly sampling (903) the digital image inside said mask and producing sample points;

d. calculating (904) for each sample point a characteristic;

e. selecting (905) a number of sampling points most likely to correspond to a spiculated lesion;

f. applying (906) a segmentation procedure to the original digital image at said selected sampling points;

g. extracting (907) new characteristics from each segmented area and obtaining a feature vector;

h. classifying (908) each feature vector as suspicious or non-suspicious using a classification machine; and

i. examining (909) said suspicious areas.

6. The method of claim 5 wherein said characteristics in said step d comprises one or several of:

contrast,

two measures of spiculatedness, and

two measures of edge orientations.

7. The method of claim 6 wherein said contrast, is derived as a ratio between an intensity inside a circle with a radius r1 and a washer shaped background area with inner radius r1 and an outer radius r2.

8. The method of claim 6 wherein said two measures of spiculatedness are derived from a histogram of angle differences obtained using a filtration method that yields phase information together with orientation estimates.

9. The method of claim 6, wherein said two measures of edge orientations are derived from a histogram of angle differences obtained using a filtration method that yields phase information together with orientation estimates.

10. The method of claim 5, wherein said step e is provided using a support vector machine or an artificial neural network.

11. The method of claim 6, wherein said classification of each feature vector is provided using a classification machine.

12. The method according to any of claims 5-10, wherein the entire image is sampled.

13. The method of claim 5, wherein each node in the applied sampling grid is evaluated in terms of contrast and spiculation.

16. An x-ray apparatus comprising an arrangement according to any of claims 12-13.

14. An arrangement (800) for detecting a Region of Interest in an image data set, especially digitalized X-ray image, which arrangement extracts phase information from said image, uses said phase information for differentiating between different lines and edges, and skews said lines towards a centre, the arrangement comprising:

a processing unit (801), a module (802) for obtaining image masks, a sampling module (803), a calculating module (804), filtration module (805), a classification module (806) and a support vector machine and/or artificial neural network module (807).

15. The arrangement of claim 14, wherein said filtration module is a set of quadrature-filter.

17. A computer unit comprising a processing unit, a memory unit, storage unit, said computer unit being operatively arranged with an instruction set to acquire an image data set, especially digitalized x-ray image, said instruction set having procedures for:

detecting a Region of Interest in a said image data, extracting phase information from said image, obtaining image masks, sampling, calculating, filtration, a classification and supporting vector and/or artificial neural network.