Patent Document ID: 5559335
Application ID: 08365087
Patent Status: 1

Claim One:
1. A diagnostic imaging system for reconstructing a volume image in an image memory from emission data projections collected at a plurality of projection angles by a radiation detector head having a cone beam convergent ray collimator, the diagnostic imaging system comprising: a projector for projecting the volume image stored in the image memory along a selected projection direction to form a two-dimensional reprojection along the selected projection direction, the projector including a warping means for transforming the volume image in two dimensions such that rays which converge at a common angle with the cone beam convergent ray collimator become parallel; a projection combining means for combining each two-dimensional reprojection from the projector with a collected emission data projection in a common projection direction to generate a two-dimensional data array; a backprojector for backprojecting the two-dimensional data array to form a volume of correction factors, the backprojector including: an unwarping means for transforming the backprojected data arrays such that parallel rays converge in two dimensions at the common angle with the cone beam convergent ray collimator, a processor for weighting the data arrays with a weighting function to generate an unwarped volume, and an unrotating means Which rotates the unwarped volume to a preselected orientation to form the volume of correction factors; and a volumetric image updating means for correcting the volume image in the image memory in accordance with the volume of correction factors.