Method and system for reconstructing 3-dimensional images from spatially and temporally overlapping x-rays

Abstract

An x-ray imaging system and method for reconstructing three-dimensional images of a region of interest from spatially and temporally overlapping x-rays using novel reconstruction techniques.

1 . An x-ray imaging system, comprising:
 a detector capable of generating a signal in response to x-rays incident upon the detector, wherein the signal indicates the intensity of the x-rays incident upon a pixel of the detector,   a plurality of x-ray sources, wherein at least two of the plurality of x-ray sources are capable of emitting x-rays such that said x-rays pass through a region of interest (ROI) and spatially and temporally overlap at the pixel of the detector; and   a processing unit capable of receiving the signal indicating the intensity of x-rays incident upon the pixel of the detector and generating an estimate of the intensity attributable to each of the two or more x-rays overlapping at the pixel of the detector.   
     
     
         2 . The system of  claim 1 , wherein the processing unit is further capable of generating a three-dimensional representation of the ROI using one or more estimates of the intensity attributable to each of the two or more x-rays overlapping at the pixel of the detector. 
     
     
         3 . The system of  claim 3 , further comprising a display operably coupled to the processing unit, wherein the display is capable of displaying one or more two-dimensional views of the three-dimensional representation of the ROI. 
     
     
         4 . The system of  claim 1 , wherein the plurality of x-ray sources comprises two or more emitter elements of a distributed source array. 
     
     
         5 . The system of  claim 1 , wherein the processing unit is further capable of voxelizing the ROI into a plurality of three-dimensional, non-overlapping voxels; estimating an attenuation coefficient attributable to each said voxel, and re-voxelizing the ROI into a plurality of three-dimensional, non-overlapping voxels based on the estimated attenuation coefficients attributable to each said voxel. 
     
     
         6 . The system of  claim 5 , wherein the processing unit is further capable of repeating said re-voxelization until a stopping criterion is met. 
     
     
         7 . The system of  claim 6 , wherein the processing unit is further capable of estimating said attenuation coefficient attributable to each voxel using a compressed sensing algorithm. 
     
     
         8 . The system of  claim 7 , wherein the compressed sensing algorithm comprises at least one of an optimization and linearization algorithm, forward-backward splitting algorithm, or combination thereof, applied to the estimated attenuation coefficients. 
     
     
         9 . The system of  claim 1 , wherein the plurality of x-ray sources and the detector each include one or more sensors capable of determining the relative positions of the x-ray sources and the detector. 
     
     
         10 . The system of  claim 1 , further comprising a controller for operating the x-ray imaging system, wherein the controller is capable of activating a subset of the plurality of x-ray sources. 
     
     
         11 . A method of reconstructing an x-ray image comprising;
 activating two or more sources to emit x-rays such that said x-rays are delivered to a region of interest (ROI) and spatially and temporally overlap at a pixel of the detector;   detecting the intensity of the overlapping x-rays incident upon the pixel of the detector; and   generating an estimate of the intensity attributable to each of the two or more x-rays overlapping at the pixel of the detector using the aggregate intensity of the overlapping x-rays incident upon the pixel of the detector.   
     
     
         12 . The method of  claim 11 , further comprising generating a three-dimensional representation of the ROI utilizing one or more estimates of the intensity attributable to each of the two or more x-rays overlapping at the pixel of the detector. 
     
     
         13 . The method of  claim 12 , further comprising displaying one or more two-dimensional views of the three-dimensional representation of the ROI. 
     
     
         14 . The method of  claim 10 , further comprising voxelizing the ROI into a plurality of three-dimensional, non-overlapping voxels; estimating an attenuation coefficient attributable to each said voxel; and re-voxelizing the ROI into a plurality of three-dimensional, non-overlapping voxels based on the estimated attenuation coefficients attributable to each said voxel. 
     
     
         15 . The method of  claim 14 , further repeating said re-voxelization until a stopping criterion is met. 
     
     
         16 . The method of  claim 15 , further comprising using a compressed sensing algorithm to estimate said attenuation coefficient attributable to each voxel. 
     
     
         17 . The method of  claim 16 , wherein said compressed sensing algorithm comprises at least one of an optimization and linearization algorithm, forward-backward splitting algorithm, or combination thereof. 
     
     
         18 . The method of  claim 11 , further comprising performing a calibration comprising the steps of activating each source to emit x-rays one at a time; and activating sets of sources to emit x-rays such that said x-rays overlap at the pixel of the detector. 
     
     
         19 . The method of  claim 11 , further comprising selecting the two or more sources to activate to emit x-rays so as to optimize at least one of image acquisition speed, image quality, and ROI coverage.