Patent ID: 8005184

Claim:
A line scan cone beam computed tomography (CT) system for generating an image of an object, the system comprising: an x-ray source mounted for translational motion along a first axis and being operable to emit x-rays in a cone beam for irradiating the object at each of a plurality of view angles; a detector array mounted for translational motion along a second axis and including a plurality of detector elements for measuring the intensity of the cone beam radiation transmitted through the object at each of the plurality of view angles; a controller for controlling movement of both the x-ray source and the detector array to successive view angles, wherein movement of the x-ray source along the first axis occurs in a direction opposite the movement of the detector array along the second axis; a data acquisition module that receives intensity measurements from the detector array corresponding to each of the plurality of view angles and produces digital signals indicative of the intensity measurements; a processor that receives the digital signals, generates a cone beam projection data set of the object therefrom, and reconstructs the image of the object using the cone beam projection data set; and wherein the processor operates to: i) convert the cone beam projection data set of the object into an equivalent parallel beam projection data set of a virtual object; ii) transform the parallel beam projection data set to a corresponding set of known Fourier space data; iii) reconstruct an initial image of the virtual object from the known Fourier space data set, the initial image having a plurality of pixels with associated values; iv) update the values of the pixels in the reconstructed virtual image, using a defined metric which measures the quality of the reconstructed image, in order to produce an updated image; v) transform the updated image to Fourier space to form an updated image Fourier space data set; vi) replace Fourier space data in the updated image Fourier space data set with corresponding known Fourier space data to form a constrained Fourier space data set; vii) reconstruct a constrained image of the virtual object from the constrained Fourier space data set; viii) repeat operations iv) through viii) until the constrained image of the virtual object meets a preset quality as determined by calculating the defined metric of the constrained reconstructed image; and ix) transform the constrained reconstructed image of the virtual object to an image of the object.