Systems and methods for generating two-dimensional images from projection data
A method for generating a two-dimensional image of an object using a CT scanner is provided. The method includes selecting an imaging surface for the object, the imaging surface including a plurality of pixels, selecting a viewing direction that is non-parallel to the imaging surface, rotating an x-ray source of the CT scanner around the object through a plurality of views, wherein the x-ray source projects x-rays towards a detector array opposite the x-ray source. For each pixel of the plurality of pixels, the method includes acquiring using the detector array, from the plurality of views, data values for x-rays that pass through the pixel and are within a pre-determined angle from parallel to the viewing direction, and combining the data values acquired for the pixel to calculate a final value for the pixel. The method further includes generating the two-dimensional image of the object based on the calculated final values for each pixel.
1. A method for generating a two-dimensional image of an object using a CT scanner, said method comprising:
selecting an imaging surface for the object, the imaging surface including a plurality of pixels;
selecting a viewing direction that is non-parallel to the imaging surface;
rotating an x-ray source of the CT scanner around the object through a plurality of views, wherein the x-ray source projects x-rays towards a detector array opposite the x-ray source;
for each pixel of the plurality of pixels:
acquiring using the detector array, from the plurality of views, data values for x-rays that pass through the pixel and are within a pre-determined angle from parallel to the viewing direction; and
combining, using a processing device, the data values acquired for the pixel while excluding other data values that do not correspond to the x-rays that pass through the pixel and are within the pre-determined angle to calculate a final value for the pixel; and
generating the two-dimensional image of the object based on the calculated final values for each pixel.
2. A method in accordance with claim 1 , wherein selecting an imaging surface comprises selecting an imaging plane.
3. A method in accordance with claim 1 , wherein selecting an imaging surface comprises selecting a non-planar surface.
4. A method in accordance with claim 1 , wherein rotating an x-ray source around the object comprises rotating the x-ray source around the object along a helical path.
5. A method in accordance with claim 1 , wherein combining the data values acquired for the pixel comprises averaging the data values acquired for the pixel.
6. A method in accordance with claim 1 , wherein acquiring data values comprises:
selecting, for each view of the plurality of views, detector elements in the detector array that receive x-rays that are within the pre-determined angle from parallel to the viewing direction; and
projecting scan data for each selected detector element onto the imaging surface.
7. A method in accordance with claim 1 , rein acquiring data values comprises:
selecting views of the plurality of views that include x-rays that are within the pre-determined angle from parallel to the viewing direction; and
projecting the scan data from the selected views for each x-ray that is within the pre-determined angle from parallel to the viewing direction onto the imaging surface.
8. A method in accordance with claim 1 , wherein selecting a viewing direction comprises selecting a viewing direction that is substantially orthogonal to the imaging surface.
9. A processing device for generating a two-dimensional image of an imaging surface of an object, the imaging surface including a plurality of pixels, said processing device configured to cause a computer to implement a method comprising:
acquiring from a detector array communicatively coupled to said processing device, for each pixel of the plurality of pixels, data values for x-rays that pass through the pixel and are within a pre-determined angle from parallel to a viewing direction, wherein the viewing direction is non-parallel to the imaging surface, wherein the x-rays are emitted from an x-ray source that rotates around the object through a plurality of views, and wherein the data values for the pixel are acquired across the plurality of views;
combining, using said processing device, the data values acquired for each pixel while excluding other data values that do not correspond to the x-rays that pass through the pixel and are within the pre-determined angle to calculate a final value for each pixel; and
generating the two-dimensional image of the imaging surface based on the calculated final values for each pixel.
10. A processing device in accordance with claim 9 , wherein the imaging surface is an imaging plane.
11. A processing device in accordance with claim 9 , wherein the imaging surface is a non-planar surface.
12. A processing device in accordance with claim 9 , wherein the x-ray source rotates around the object along a helical path.
13. A processing device in accordance with claim 9 , wherein combining the data values acquired for each pixel comprises averaging the data values acquired for each pixel.
14. A processing device in accordance with claim 9 , wherein acquiring data values comprises:
selecting, for each view of the plurality of views, detector elements in the detector array that receive x-rays that are within the pre-determined angle from parallel to the viewing direction; and
projecting scan data for each selected detector element onto the imaging surface.
15. A processing device in accordance with claim 9 , wherein acquiring data values comprises:
selecting views of the plurality of views that include x-rays that are within the pre-determined angle from parallel to the viewing direction; and
projecting the scan data from the selected views for each x-ray that is within the pre-determined angle from parallel to the viewing direction onto the imaging surface.
16. A processing device in accordance with claim 9 , wherein the viewing direction is substantially orthogonal to the imaging surface.
17. A CT system for imaging an object, said CT system comprising:
a CT scanner comprising:
an x-ray source configured to rotate around the object through a plurality of views and project x-rays towards the object; and
a detector array positioned opposite said x-ray source; and
a storage medium communicatively coupled to said detector array and encoded with machine readable computer program code for generating a two-dimensional image of an imaging surface of the object, the imaging surface including a plurality of pixels, the storage medium including instructions for causing a computer to implement a method comprising:
acquiring from said detector array, for each pixel of the plurality of pixels, data values for x-rays that pass through the pixel and are within a pre-determined angle from parallel to a viewing direction, wherein the viewing direction is non-parallel to the imaging surface, and wherein the data values for the pixel are acquired across the plurality of views;
combining, using the computer, the data values acquired for each pixel while excluding other data values that do not correspond to the x-rays that pass through the pixel and are within the pre-determined angle to calculate a final value for each pixel; and
generating the two-dimensional image of the imaging surface based on the calculated final values for each pixel.
18. A CT system in accordance with claim 17 , wherein the imaging surface is an imaging plane.
19. A CT system in accordance with claim 17 , wherein the imaging surface is a non-planar surface.
20. A CT system in accordance with claim 17 , wherein combining the data values acquired for each pixel comprises averaging the data values acquired for each pixel.