System and method for tree projection for detection of pulmonary embolism
View Patent ↗A system and method for detecting an area of interest such as a pulmonary embolism in a structure of interest such as a vessel tree or airway tree are provided. The method comprises: segmenting image data of the structure of interest; and rendering two-dimensional images based on a function of the image data and the segmented image data within slabs defined by the segmented image data.
1. A method for detecting a pulmonary embolism (PE), comprising:
receiving original image data of a structure of interest;
segmenting the original image data of the structure of interest;
rendering two-dimensional images of the structure of interest,
wherein the rendering of a two-dimensional image is performed in a single rendering operation,
wherein the single rendering operation comprises casting at least one ray through a slab of a plurality of slabs of the original and segmented image data, identifying voxels of both the original and segmented image data that are encountered by the ray, not rendering the original image data encountered by the ray and rendering original image data that corresponds to the segmented image data encountered by the ray, and
wherein the voxels considered for the rendering are solely defined by the segmentation and the individual slab through which the at least one ray is cast; and
displaying the two-dimensional image to assist a user in identifying an unmarked PE inside the structure of interest.
2. The method of claim 1 , wherein the structure of interest is segmented using one of a thresholding and size-based labeling, line-filter based or structure tensor-based segmentation technique.
3. The method of claim 1 , wherein, when the structure of interest is a pulmonary vessel tree, the step of rendering comprises:
initially orienting the slabs along an axis of the pulmonary vessel tree;
sizing the slabs to cover one of left and right lungs or one of the left or right lungs of the pulmonary vessel tree;
computing projections of the slabs rotated about the pulmonary vessel tree; and
slicing the pulmonary vessel tree.
4. The method of claim 3 , wherein the slabs are initially oriented along one of the x, y or z axis.
5. The method of claim 3 , wherein the slabs are initially oriented along one of an axis defined by a patient's anatomy or a central axis of the pulmonary vessel tree.
6. The method of claim 1 , wherein the number of two-dimensional images is defined by:
N
=
π
2
×
tan
-
1
(
t
/
(
2
×
r
)
)
,
where N is the number of two-dimensional images taken as a ceiling value of the fraction, t is a thickness of the slabs and r is a radius of influence.
7. The method of claim 1 , wherein the number of two-dimensional images is defined by:
N
=
π
×
r
t
,
where N is the number of two-dimensional images taken as a ceiling value of the fraction, t is a thickness of the slabs and r is a radius of influence.
8. The method of claim 1 , wherein the number of slabs is defined by one of a function of the slab thickness, slab overlap or radius of the structure of interest.
9. The method of claim 1 , further comprising:
presenting the slabs as a cine loop.
10. The method of claim 9 , further comprising:
adjusting the cine loop.
11. The method of claim 10 , wherein the adjustment is one of speed, slab thickness, rotation axis or rendering method.
12. The method of claim 1 , wherein the individual slab is about 11 mm to about 25 mm thick.
13. A non-transitory computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method for detecting a pulmonary embolism (PE) in a pulmonary vessel tree, the method comprising:
receiving original image data of a pulmonary vessel tree;
segmenting the original image data of the pulmonary vessel tree;
rendering two-dimensional images of the pulmonary vessel tree,
wherein the rendering of a two-dimensional image is performed in a single rendering operation,
wherein the single rendering operation comprises casting at least one ray through a slab of a plurality of slabs of the original and segmented image data, identifying voxels of both the original and segmented image data that are encountered by the ray, not rendering the original image data encountered by the ray and rendering original image data that corresponds to the segmented image data encountered by the ray, and
wherein the voxels considered for the rendering are solely defined by the segmentation and the individual slab through which the at least one ray is cast; and
displaying the two-dimensional image to assist a user in identifying an unmarked PE inside the pulmonary vessel tree.
14. The computer readable storage medium of claim 13 , wherein the pulmonary vessel tree is segmented using one of a thresholding and size-based labeling, line-filter based or structure tensor-based segmentation technique.
15. The computer readable storage medium of claim 13 , wherein the step of rendering comprises:
initially orienting the slabs along an axis of the pulmonary vessel tree;
sizing the slabs to cover one of left and right lungs or one of the left or right lungs of the pulmonary vessel tree;
computing projections of the slabs rotated about the pulmonary vessel tree at increasing angles; and
slicing the pulmonary vessel tree by sweeping through a complete circle.
16. The computer readable storage medium of claim 15 , wherein the slabs are initially oriented along one of the x, y or z axis, an axis defined by a patient's anatomy or a central axis of the pulmonary vessel tree.
17. The computer readable storage medium of claim 13 , wherein the number of two-dimensional images is defined by:
N
=
π
2
×
tan
-
1
(
t
/
(
2
×
r
)
)
,
where N is the number of two-dimensional images taken as a ceiling value of the fraction, t is a thickness of the slabs and r is a radius of influence.
18. The computer readable storage medium of claim 13 , wherein the number two-dimensional images is defined by:
N
=
π
×
r
t
,
where N is the number of two-dimensional images taken as a ceiling value of the fraction, t is a thickness of the slabs and r is a radius of influence.
19. The computer readable storage medium of claim 13 , wherein the number of slabs is defined by one of a function of the slab thickness, slab overlap or radius of the structure of interest.
20. The computer readable storage medium of claim 13 , further comprising:
presenting the slabs as a cine loop; and
adjusting the cine loop, wherein the adjustment is one of speed, slab thickness, rotation axis or rendering method.
21. A system for detecting a pulmonary embolism (PE) in a structure of interest, comprising:
a memory device for storing a program;
a processor in communication with the memory device, the processor operative with the program to:
receive original image data of a structure of interest;
segment the original image data of the structure of interest;
render two-dimensional images of the structure of interest,
wherein the rendering of a two-dimensional image is performed in a single rendering operation,
wherein the single rendering operation comprises casting at least one ray through a slab of a plurality of slabs of the original and segmented image data, identifying voxels of both the original and segmented image data that are encountered by the ray, not rendering the original image data encountered by the ray and rendering original image data that corresponds to the segmented image data encountered by the ray, and
wherein the voxels considered for the rendering are solely defined by the segmentation and the individual slab through which the at least one ray is cast; and
display the two-dimensional image to assist a user in identifying an unmarked PE inside the structure of interest.
22. The system of claim 21 , wherein the image data is acquired using one of a computed tomography or magnetic resonance imaging device.
23. The system of claim 21 , wherein, when rendering, the processor is further operative with the program to:
initially orient the slabs along a central axis of the structure of interest;
compute projections of the slabs rotated about the structure of interest at increasing angles; and
slice the structure of interest.
24. The system of claim 21 , wherein the processor is further operative with the program to:
present the slabs as a cine loop.
25. The system of claim 24 , wherein the processor is further operative with the program to:
adjust the cine loop.