System and method for detecting the aortic valve using a model-based segmentation technique

1. A method for detecting an aortic valve, comprising:

(a) casting a plurality of rays from a seed point within a slice of a computed tomography (CT) dataset of an aorta;

(b) computing a Gaussian model for voxels in the slice, wherein the Gaussian model produces a threshold;

(c) growing a circle on the slice from a point within the aorta until control points of the circle reach the threshold;

(d) computing a repulsion vector for each control point reaching the threshold;

(e) repositioning the circle according to an average of the repulsion vectors until the circle is not within the aorta;

(f) projecting a copy of the circle onto an adjacent slice of the CT dataset;

(g) reducing the radius of the copy of the circle and taking at least one statistical measurement of the copy if the radius is below the threshold;

repeating steps (c-g) on remaining slices of the CT dataset until the aortic valve is detected by using at least one of the statistical measurements;

segmenting the aorta constrained by the location of the aortic valve; and

displaying the segmented aorta.

2. The method of claim 1 , wherein the aortic valve is detected by a decrease in the radius of the copy of at least one circle.

3. The method of claim 1 , wherein the aorta is segmented using a region growing technique or an intensity-based segmentation algorithm constrained by the location of the aortic valve.

4. The method of claim 1 , wherein in step (g) the radius of the copy of the circle is reduced by fifty percent.

5. The method of claim 1 , wherein the seed point is selected by a user clicking on a portion of the slice.

6. The method of claim 1 , wherein the length of each of the plurality of rays is defined by an estimated aorta radius.

7. The method of claim 1 , wherein the CT dataset is acquired by a CT or helical CT imaging technique.

8. A system for detecting an aortic valve, comprising:

a memory device for storing a program;

a processor in communication with the memory device, the processor operative with the program to;

(a) cast a plurality of rays from a seed point within a slice of a computed tomography (CT) dataset of an aorta;

(b) compute a Gaussian model for voxels in the slice, wherein the Gaussian model produces a threshold;

(c) grow a circle on the slice from a central point within the aorta until control points of the circle reach the threshold;

(d) compute a repulsion vector for each control point reaching the threshold;

(e) reposition the circle according to an average of the repulsion vectors until the circle is not within the aorta;

(f) project a copy of the circle onto an adjacent slice of the CT dataset;

(g) reduce the radius of the copy of the circle and take at least one statistical measurement of the copy if the radius is below the threshold; and

repeat steps (c-g) on remaining slices of the CT dataset until the aortic valve is detected by using at least one of the statistical measurements.

9. The system of claim 8 , wherein the processor is further operative with the program to:

segment the aorta using a region growing technique or an intensity-based segmentation algorithm constrained by the location of the aortic valve, wherein the aortic valve is detected by a decrease in the radius of the copy of at least one circle.

10. The system of claim 8 , wherein in step (g) the radius of the copy of the circle is reduced by fifty percent.

11. The system of claim 8 , wherein the CT dataset is acquired by a CT or helical CT imaging device.

12. A method for detecting an aortic arch, comprising:

(a) casting a plurality of rays from a seed point within a slice of a computed tomography (CT) dataset of an aorta;

(b) computing a Gaussian model for voxels in the slice, wherein the Gaussian model produces a threshold;

(c) growing a circle on the slice from a point within the aorta until control points of the circle reach the threshold;

(d) computing a repulsion vector for each control point reaching the threshold;

(e) repositioning the circle according to an average of the repulsion vectors until the circle is not within the boundaries of the aorta;

(f) projecting a copy of the circle onto an adjacent slice of the CT dataset;

(g) reducing the radius of the copy of the circle and taking at least one statistical measurement of the copy if the radius is below the threshold;

repeating steps (c-g) on remaining slices of the CT dataset until the aortic arch is detected by using at least one of the statistical measurements;

segmenting the aorta constrained by the location of the aortic arch; and

displaying the segmented aorta.

13. The method of claim 12 , wherein the aortic arch is detected by a decrease in the radius of the copy of at least one circle or a decrease in the average voxel intensities of at least one circle.

14. A system for detecting an aortic arch, comprising:

a memory device for storing a program;

a processor in communication with the memory device, the processor operative with the program to:

(a) cast a plurality of rays from a seed point within a slice of a computed tomography (CT) dataset of an aorta;

(b) compute a Gaussian model for voxels in the slice, wherein the Gaussian model produces a threshold;

(c) grow a circle on the slice from a point within the aorta until control points of the circle reach the threshold;

(d) compute a repulsion vector for each control point reaching the threshold;

(e) reposition the circle according to an average of the repulsion vectors until the circle is not within the boundaries of the aorta;

(f) project a copy of the circle onto an adjacent slice of the CT dataset;

(g) reduce the radius of the copy of the circle and take at least one statistical measurement of the copy if the radius is below the threshold; and

repeat steps (c-g) on remaining slices of the CT dataset until the aortic arch is detected by using at least one of the statistical measurements.

15. The system of claim 14 , wherein the aortic arch is detected by a decrease in the radius of the copy of at least one circle or a decrease in the average voxel intensities of at least one circle.

16. The system of claim 8 , wherein the aortic valve is detected by a decrease in the radius of the copy of at least one circle.

17. The system of claim 8 , wherein the seed point is selected by a user clicking on a portion of the slice.

18. The system of claim 8 , wherein the length of each of the plurality of rays is defined by an estimated aorta radius.