Segmentation of a calcified blood vessel

1. A method for segmentation of a calcified blood vessel in image data, comprising:

providing a vesseltree representation of the blood vessel;

providing a number of preliminary boundary representations of a number of cross-sections of the blood vessel;

providing a number of intensity profiles in the image data in the number of cross-sections;

obtaining a threshold intensity level based on ranges of an intensity distribution of the intensity profile corresponding to at least one cross-section of the number of cross-sections;

determining a calcification in the at least one cross-section based on the threshold intensity level; and

correcting each preliminary boundary representation into a corrected boundary representation which excludes the calcification from an inner part of the blood vessel.

2. The method of claim 1 , wherein the providing the number of intensity profiles determines the number of intensity profiles in the number of cross-sections along a number of profile rays from one seed point within the blood vessel in each cross-section towards the preliminary boundary representation.

3. The method of claim 1 , wherein the determining the calcification determines the calcification in a region having an intensity above the threshold level.

4. The method of claim 3 , wherein the image data are based on X-ray acquisition and wherein the threshold intensity level is above 576 HU.

5. The method of claim 1 , wherein a result from the determination of the calcification is compared to an extension of the preliminary boundary representation for validation of the result.

6. The method of claim 1 , wherein the vesseltree representation comprises a centerline of the blood vessel.

7. The method of claim 6 , wherein the providing the vesseltree includes recentering the centerline at least once.

8. The method of claim 1 , further comprising:

warping the image data such that the vesseltree representation is aligned along a straight line and at least one of the number of preliminary and corrected boundary representations are aligned parallel to one another.

9. The method of claim 1 , wherein the providing the number of preliminary boundary representations includes deriving likelihood values of candidate points in the respective cross-section.

10. The method of claim 9 , wherein the deriving derives the likelihood values using a trained classifier algorithm.

11. A method for segmentation of a calcified blood vessel in image data, comprising:

providing a vesseltree representation of the blood vessel;

providing a number of preliminary boundary representations of a number of cross-sections of the blood vessel;

providing a number of intensity profiles in the image data in the number of cross-sections;

determining a calcification in at least one of the cross-sections based on the corresponding intensity profile;

correcting each preliminary boundary representation into a corrected boundary representation which excludes the calcification from an inner part of the blood vessel;

providing an image representation of the calcified blood vessel;

providing a start surface model, including a mesh with a plurality of vertices connected by edges;

defining, for each vertex, a ray normal to the surface model at the position of the vertex;

assigning more than two labels to each vertex, each label representing a candidate position of the vertex on the ray;

providing, based in the corrected boundary representation, a representation of likelihoods for each candidate position the likelihood referring to whether the candidate position corresponds to a surface point of the blood vessel in the image representation;

defining a first order Markov Random Field with discrete multivariate random variables, the random variables comprising the labels of the candidate positions and the representation of likelihoods; and

finding an optimal segmentation of the calcified blood vessel by using a maximum a posteriori estimation in this Markov Random Field.

12. A segmentation system for segmentation of a calcified blood vessel in image data, comprising:

an input interface for the image data;

a first provision unit configured to provide a vesseltree representation of the blood vessel,

a second provision unit configured to provide a number of preliminary boundary representations of a number of cross-sections of the blood vessel;

a third provision unit configured to provide a number of intensity profiles in the image data in the number of cross-sections;

a determination unit configured to,

obtain the threshold intensity level based on ranges of an intensity distribution of the intensity profile corresponding to at least one cross-section of the number of cross-sections, and

determine a calcification in the at least one cross-section based on the threshold intensity level; and

a correction unit configured to correct each preliminary boundary representation into a corrected boundary representation which excludes the calcification from an inner part of the blood vessel.

13. A tomographic imaging device comprising:

an acquisition unit; and

the segmentation system of claim 12 .

14. A non-transitory computer program product directly loadable into a processor of a programmable segmentation system comprising program code segments to perform the method of claim 1 when the computer program product is executed on the segmentation system.

15. The method of claim 7 , wherein the providing the vesseltree includes recentering the centerline at least once after correcting the preliminary boundary representation.

16. A non-transitory computer readable medium including program code segments for, when executed on a programmable segmentation system, causing the programmable segmentation system to implement the method of claim 1 .

17. A non-transitory computer readable medium including program code segments for, when executed on a programmable segmentation system, causing the programmable segmentation system to implement the method of claim 11 .

18. The method of claim 1 , wherein the threshold level is based on a variance of the intensity profile corresponding to the at least one cross-section.

19. The method of claim 1 , wherein the obtaining obtains the threshold intensity level based on a variance of the intensity profile corresponding to the at least one cross-section.

20. The method of claim 1 , wherein the correcting corrects each preliminary boundary representation into the corrected boundary representation using a piecewise function.