Image generation via computed tomography system
Among other things, computed tomography (CT) systems and/or techniques for generating projections images of an object(s) under examination via a CT system are provided. The projection images of the object may represent a projection of the entire object or merely a portion of the object, such as a slice of the object. A surface about which the projection image is focused is defined and data yielded from a plurality of views of the object is mapped to the surface. In some embodiments, such a mapping comprises mapping data corresponding to a first view and yielded from a first detector cell to a first point on the surface, mapping data corresponding to the first view and yielded from a second detector cell to a second point on the surface, and/or mapping data corresponding to a second view and yielded from the first detector cell to a third point on the surface.
1. A method for generating a projection image from volumetric data, comprising:
acquiring volumetric data yielded from an examination of an object via radiation;
defining a surface about which a projection image of the object to be generated is focused;
mapping a first portion of the volumetric data, corresponding to a first view, to a first location on the surface based on a first intersection of at least one ray and the first location on the surface;
mapping a second portion of the volumetric data, corresponding to a second view, to a second location on the surface based on a second intersection of at least one other ray and second location on the surface; and
generating the projection image from the volumetric data based upon the mapping a first portion and the mapping a second portion.
2. The method of claim 1 , the mapping a first portion comprising:
determining a first trajectory between a radiation source emitting the radiation during the first view and a predefined location on a first detector cell;
identifying a first intersection between the first trajectory and the first location on the surface;
and mapping first data yielded from the first detector cell and corresponding the first view to the first intersection.
3. The method of claim 2 , the mapping a first portion further comprising:
determining a second trajectory between the radiation source during the first view and a predefined location on a second detector cell;
identifying a second intersection between the second trajectory and a third location on the surface; and
mapping second data yielded from the second detector cell and corresponding to the first view to the second intersection.
4. The method of claim 3 , comprising:
determining a first characteristic of a first pixel of the projection image based upon the first data; and
determining a second characteristic of a second pixel of the projection image based upon the second data.
5. The method of claim 2 , the mapping a second portion comprising:
determining a second trajectory between the radiation source during the second view and the predefined location on the first detector cell;
identifying a second intersection between the second trajectory and the second location on the surface; and
mapping second data yielded from the first detector cell and corresponding to the second view to the second intersection.
6. The method of claim 5 , the first trajectory different than the second trajectory.
7. The method of claim 5 , comprising:
determining a first characteristic of a first pixel of the projection image based upon the first data; and
determining a second characteristic of a second pixel of the projection image based upon the second data.
8. The method of claim 7 , wherein at least one of the first characteristic or the second characteristic is an intensity characteristic.
9. The method of claim 1 , wherein the volumetric data represents merely a slice of the object.
10. The method of claim 1 , wherein the surface is planar.
11. The method of claim 1 , wherein the surface is non-planar.
12. The method of claim 1 , the defining a surface comprising:
identifying, based upon the volumetric data, a region of the object that is of interest; and
defining the surface based upon the region of the object that is of interest.
13. The method of claim 1 , wherein:
the mapping a first portion comprises:
determining a first trajectory between a radiation source emitting the radiation during the first view and a predefined location on a first detector cell;
identifying the first intersection between the first trajectory and the first location on the surface;
mapping first data yielded from the first detector cell and corresponding the first view to the first intersection;
determining a second trajectory between the radiation source during the first view and a predefined location on a second detector cell;
identifying the second intersection between the second trajectory and a third location on the surface; and
mapping second data yielded from the second detector cell and corresponding to the second view to the second intersection; and
the mapping a second portion comprises:
determining a third trajectory between the radiation source during the second view and the predefined location on the first detector cell;
identifying a third intersection between the third trajectory and the second location on the surface; and
mapping third data yielded from the first detector cell and corresponding to the second view to the third intersection.
14. The method of claim 1 , wherein the surface comprises a topological manifold.
15. The method of claim 1 , wherein the surface lies outside of the object.