Tomographic image acquisition using asymmetrical pixel binning
A computer implemented method for reconstructing a 3-D volume image using a radiographic imaging system having one or more x-ray sources and a digital detector. A plurality of radiographic images of a subject at various angles are captured in the digital detector. Image data in two or more pixels of the detector that are adjacent to each other in a row direction or a column direction are combined, while pixels adjacent in the other direction are not combined.
1. A computer implemented method for reconstructing a 3-D radiographic image of a subject using a plurality of 2-D radiographic images of the subject captured by a radiographic imaging system having an x-ray source and a digital x-ray detector, wherein the detector comprises rows and columns of pixels, the method comprising:
moving the x-ray source in a selected direction to a plurality of imaging positions while maintaining the detector stationary;
determining a binning direction that is parallel to the rows of pixels in the detector or to the columns of pixels in the detector based on a hardware configuration of the detector and that is parallel to the selected direction of moving the x-ray source;
acquiring the plurality of 2-D radiographic images of the subject each at one of the plurality of imaging positions, including combining captured image data in two or more pixels of the detector that are adjacent to each other in to the determined binning direction;
reconstructing the 3-D radiographic image of the subject using the acquired plurality of 2-D radiographic images; and
displaying at least a portion of the reconstructed 3-D radiographic image.
2. The method of claim 1 , further comprising connecting the rows of pixels to a gate driver configured to simultaneously activate two or more rows of the pixels.
3. The method of claim 2 , further comprising reading out image data captured in any pixels in a column that are activated by the gate driver.
4. The method of claim 1 , wherein the step of acquiring includes not combining image data captured in adjacent pixels of the detector that are not adjacent in the determined binning direction.
5. The method of claim 4 , wherein the step of reconstructing the 3-D radiographic image includes using a same voxel resolution that is used for captured image data in the two or more adjacent pixels that are not combined.
6. The method of claim 1 , wherein the step of combining captured image data includes determining an average pixel value of the two or more adjacent pixels and using the average pixel value as the pixel value in each of the two or more adjacent pixels.
7. A computer implemented method for tomographic image reconstruction using a radiographic imaging system having one or more x-ray sources and a digital detector, the method comprising:
acquiring a plurality of radiographic images of a subject in the digital detector, including acquiring the radiographic images each at one of a plurality of positions during a relative motion as between the one or more x-ray sources and the digital detector, wherein the relative motion is parallel to a row orientation of pixels in the detector or to a column orientation of the pixels in the detector; and
reading out the radiographic images of the subject from the detector, including combining captured image data in two or more pixels of the detector that are adjacent to each other in a direction parallel to the row orientation of pixels in the detector or parallel to the column orientation of the pixels in the detector, including selecting the direction parallel to the row orientation or the column orientation and parallel to the relative motion direction of the detector and based on a hardware configuration of the detector.
8. The method of claim 7 , further comprising connecting the pixels in the row orientation to a gate driver configured to simultaneously activate two or more rows of the pixels in the row orientation.
9. The method of claim 8 , further comprising reading out image data captured in any pixels in the column orientation that are activated by the gate driver.
10. The method of claim 7 , wherein the step of combining captured image data includes determining an average pixel value of the two or more pixels of the detector that are adjacent to each other and using the average pixel value to represent the combined captured image data in the two or more adjacent pixels.
11. A computer implemented method for tomographic image reconstruction using a radiographic imaging system having one or more x-ray sources and a digital detector, the method comprising:
determining a binning direction to be used to acquire radiographic images of a subject consistent with a direction of a relative motion as between the one or more x-ray sources and the subject, and determining the binning direction based on a hardware configuration of the digital detector;
capturing a plurality of projection images of the subject in the detector including changing the relative angle as between the one or more x-ray sources and the subject for each captured projection image;
binning the image data of each projection image captured in the detector in the determined binning direction to acquire the radiographic images of the subject;
reconstructing a tomographic image of the subject using the acquired radiographic images of the subject; and
displaying at least a portion of the reconstructed tomographic image.
12. The method of claim 11 , wherein the step of determining a binning direction comprises generating orientation instructions and displaying the orientation instructions to an operator.
13. The method of claim 12 , wherein the step of generating orientation instructions comprises providing one or more signals to an actuator to rotate the detector.
14. The method of claim 11 , further comprising connecting rows of pixels in the detector to a gate driver configured to simultaneously activate two or more rows of the pixels.
15. The method of claim 14 , further comprising reading out image data captured in any pixels in a column that are activated by the gate driver.
16. The method of claim 11 , wherein the step of determining the binning direction comprises determining an anatomical portion of a subject being imaged.
17. The method of claim 16 , wherein the step of determining the binning direction further comprises looking up the binning direction in a LUT using the anatomical portion as an index into the LUT.
18. The method of claim 11 , wherein the step of capturing a plurality of projection images comprises individually energizing x-ray sources in an array of carbon nanotube x-ray sources.