System and method of automatic prioritization and analysis of medical images

• US 8,331,637 B2
• Filed: 02/18/2007
• Issued: 12/11/2012
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Medic Vision - Brain Technologies Ltd.
• Original Assignee: Medic Vision - Brain Technologies Ltd.
• Inventors: Bar-Aviv, Ezer, Dahan, Eliran, Devir, Zvi
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): Rhodes, Jr., Leon W.
• Application Number:
  US12/224,652
• Publication Number:
  US 20090028403A1
• Time in Patent Office: 2,123 Days
• Field of Search: 382/128, 382/131
• US Class Current: 382/128
• CPC Class Codes: G06T 2207/20128 Atlas-based segmentation
• CPC Class Codes: G06T 2207/20161 Level set
• CPC Class Codes: G06T 2207/30016 Brain
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/149 involving deformable models, e.g. active contour models
• CPC Class Codes: G06T 7/75 involving models
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 10/40 Extraction of image or video features
• CPC Class Codes: G06V 10/754 involving a deformation of the sample pattern or of the reference pattern; Elastic matching
• CPC Class Codes: G06V 2201/032 of protuberances, polyps nodules, etc.
• CPC Class Codes: G16H 15/00 ICT specially adapted for medical reports, e.g. generation or transmission thereof
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 70/60 relating to pathologies

Abstract

A system for analyzing a source medical image of a body organ. The system comprises an input unit for obtaining the source medical image having three dimensions or more, a feature extraction unit that is designed for obtaining a number of features of the body organ from the source medical image, and a classification unit that is designed for estimating a priority level according to the features.

Claims

1. A system for analyzing a source medical image of a body organ, said system comprising:

a) an input unit for obtaining the source medical image, the source medical image having at least three dimensions;

b) a segmentation unit, operatively associated with said input unit, configured for segmenting the source medical image into a segmented source medical image by matching the source medical image with a reference medical image of a respective normal organ, said segmented source medical image including a plurality of source segments, said reference medical image already being segmented into a plurality of reference segments, said reference medical image having at least three dimensions;

c) a feature extraction unit, operatively associated with said segmentation unit, configured for obtaining a plurality of features of the body organ from the segmented source medical image; and

d) a pathology detector unit, operatively associated with said feature extraction unit, configured for indicating at least one pathology based on said plurality of features.

2. The system of claim 1, wherein the body organ is a brain.

3. The system of claim 2, wherein at least one of said features is calculated according to the uniformity of a skull that being depicted in the source medical image.

4. The system of claim 2, wherein at least one of said features is calculated according to the ratio between the measures of ventricles depicted in the source medical image.

5. The system of claim 2, wherein at least one of said features is calculated according to the volume of a cerebrospinal fluid (CSF) in an upper temple depicted in the source medical image.

6. The system of claim 2, wherein at least one of said features is calculated according a minimum mean square error between said reference image and the source medical images.

7. The system of claim 2, wherein at least one of said features is calculated according an estimation of cerebrospinal fluid of in a sub-arachnoid'"'"'s space in said depicted human brain.

8. The system of claim 2, wherein at least one of said features is calculated according to the positioning of a middle symmetry line that bisects said depicted human brain.

9. The system of claim 8, wherein said symmetry is based on the symmetry level of an MSP.

10. The system of claim 8, wherein at least one of said features is calculated according to a symmetry value, said symmetry value being calculated by measuring the size of at least one portion of at least one hemisphere depicted in the source medical image.

11. The system of claim 2, wherein at least one of said features is calculated according to a distance between at least two temporal horns depicted in the source medical image.

12. The system of claim 1, wherein each of said plurality of reference segments includes a collection of normative values for said features.

13. The system of claim 12, wherein each of said plurality of source segments has at least one associated normative value.

14. The system of claim 13, wherein said features include at least four different features.

15. The system of claim 12, wherein at least one of said features is selected from the group comprising features that are:

(a) calculated according to the volume of an area of the body organ in relation to a respective volume of a respective area in said respective normal organ;

(b) calculated according to the center-of-mass of an area of the body organ in relation to a respective center-of-mass in a respective area in said respective normal organ;

(c) calculated according to second order moments of an area of the body organ;

(d) calculated according to the surface area of an area of the body organ in relation to a respective surface area in a respective area in said respective normal organ;

(e) calculated according to the average color of voxels in an area of the body organ;

(f) calculated according to one or more characteristics of the shape of an area of the body organ in relation to a respective one or more characteristics of the shape of a respective area in said respective normal organ;

(g) calculated according to the global motion in an area of the body organ in relation to the positioning of said respective normal organ;

(h) calculated according to hyperdense/hypodense areas in an area of the body organ;

(i) calculated according to the symmetry between at least two areas of the body organ; and

(j) calculated according to a mean color of at least one area in the source medical image.

16. The system of claim 15, wherein said one or more characteristics are estimated according to a spherical Fourier transform.

17. The system of claim 15, wherein said one or more characteristics are estimated according to a predefined curvature.

18. The system of claim 1, wherein at least some of said features relate to a symmetry of the body organ and at least one of said features relates to non-symmetry of the body organ.

19. The system of claim 1, further comprising a registration module being configured for performing a spatial image registration according to spatial positioning differences between the body organ and said respective normal organ, said spatial positioning differences being used by said segmentation unit for said segmenting.

20. The system of claim 19, wherein said registration module comprises a global motion sub-module being configured for estimating a global motion vector according to said spatial positioning differences, said global motion vector being used during said spatial image registration.

21. The system of claim 19, wherein said registration module comprises a 3D affine transformation sub-module being configured for estimating an affine transformation vector according to said spatial positioning differences, said affine transformation vector being used during said spatial image registration and wherein said reference medical image is associated with a plurality of reference descriptors, said 3D affine transformation sub-module being configured for identifying a plurality of source descriptors in the source medical image said, said spatial positioning differences being determined according to spatial positioning differences between said reference and source descriptors.

22. The system of claim 21, wherein said reference descriptors and said source descriptors are local extrema voxels in said reference medical image and the source medical image respectively.

23. The system of claim 19, wherein said registration module comprises an optic flow sub-module, wherein said optic flow sub-module is configured for estimating a spatial optic-flow field according to said spatial positioning differences, said optic-flow field being used during said spatial image registration.

24. The system of claim 1, wherein said segmentation unit generates said plurality of source segments by matching voxels of said reference medical image with voxels of the source medical image.

25. The system of claim 1, wherein said plurality of source segments are used for identifying said plurality of features.

26. The system of claim 1, further comprising an active contour (AC) module, said segmentation unit being configured to forward said plurality of source segments to said AC module, said AC module being configured to refine said plurality of source segments according to the source medical image.

27. The system of claim 26, wherein said refinement is performed according to the Hounsfield unit (HU) values of voxels of said plurality of source segments.

28. The system of claim 1, wherein the body organ is a depicted human brain which is segmented according to two or more of:

white matter, gray matter lateral ventricles, caudate nucleus, internal capsule, thalamus, lentiform nucleaus, sylvian fissure.

29. The system of claim 1, wherein at least one of said features is calculated according to the existence of predefined structures in said segmented source medical image, said existence is determined by matching segments of said segmented source medical image with a set of normal segmentation structures.

30. The system of claim 1, wherein at least one of said features is calculated according a distance between segments in said segmented source medical image.

31. The system of claim 1, comprising a classification unit which further comprises a diagnosis module, said diagnosis module being configured for generating a diagnosis report according to said features and said pathology detector.

32. The system of claim 1, comprising a classification unit comprises at least one classifier, said at least one classifier being configured to classify the source medical image according to said features, said classification being determined according to said at least one classifier.

33. The system according to claim 1, wherein said pathology detector analyses a vector including a plurality of features, and wherein said detector includes a memory storing therein a plurality of matches between vectors and abnormal situations.

34. The system according to claim 1, wherein said pathology detector aggregates a plurality of features into a single aggregate feature.

35. The system according to claim 1, wherein said features includes two or more of a HU density related property, a statistical scattering property of the HU density, a geometrical characteristic, a symmetry characteristic, a geometrical relation between different structures.

36. The system according to claim 1, wherein said pathology detector includes a collection of features and normative values for each segment of said.

37. A method for analyzing a source medical image of a body organ, said method comprising:

a) receiving the source medical image;

b) segmenting the source medical image into a segmented source medical image by matching the source medical image with a reference medical image of a respective normal organ, said segmented source medical image including a plurality of source segments, said reference medical image already being segmented into a plurality of reference segments;

c) obtaining information about features in the body organ from said segmented source medical image; and

d) detecting at least one deviation from normality in the body organ based on said features.