Method and system for creating three-dimensional images using tomosynthetic computed tomography

Abstract

A system for constructing image slices through a selected object, the system comprising an identifiable fiducial reference in a fixed position relative to the selected object, wherein the fiducial reference comprises at least two identifiable reference markers. A source of radiation is provided for irradiating the selected object and the fiducial reference to form a projected image of the selected object and the fiducial reference which is recorded by a recording medium.

1 - 23 . (canceled) 
     
     
         24 . A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the steps of:
 a. receiving the plurality of projected images of a region of interest of a selected object and a fiducial reference, the images recorded at different arbitrary relative positions between (1) a source of radiation, (2) the selected object and fiducial reference, and (3) a recording means; and   b. synthesizing an image slice of the selected object at a selected slice position through the object from the projected images.   
     
     
         25 . The computer program product according to  claim 24 , the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the step of computing the effective magnification of each projected image by determining a radiographic diameter of the projected image of a reference marker of the fiducial reference, and scaling each projected image to the same magnification. 
     
     
         26 . The computer program product according to  claim 25 , wherein computing the effective magnification of each projected image comprises determining when the gradient along a minor diameter of the image of the reference marker is a maximum. 
     
     
         27 . The computer program product according to  claim 26 , wherein computing the minor diameter comprises generating a series of tomosynthetic slices through the center of the reference marker using a range of values for the reference marker diameter decreasing systematically from the actual value. 
     
     
         28 . The computer program product according to  claim 24 , wherein the step of synthesizing an image slice comprises aligning the projected images based on parameters related to a first marker of the fiducial reference displayed in the plurality of images and projectively warping a projected image from an actual projection plane to a virtual projection plane using parameters related to a second reference marker of the fiducial reference displayed in the plurality of images. 
     
     
         29 . The computer program product according to  claim 24 , the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the step of generating a projected transformation matrix. 
     
     
         30 . The computer program product according to  claim 29 , wherein the step of generating the projected transformation matrix comprises mapping the position of a reference marker of the fiducial reference displayed in the projected image onto a corresponding position of the reference marker in a virtual projection plane. 
     
     
         31 . The computer program product according to  claim 24 , wherein the step of synthesizing an image of the selected object at a selected slice position through the object includes the steps of:
 a. projectively warping each projected image onto a virtual projection plane;   b. generating an image slice through the object at a selected slice position.