Patent ID: 8478015
Filing Date: 2013-07-02
Classification: A61B,G06T

Abstract:
1. A method for extending the effective FOV of a CT scanner, comprising the steps of: a) defining a projection data mask for CT transmission data to be acquired as CT projection data; b) defining a reconstruction mask for acquired CT projection data surrounding a FOV of said CT scanner to be used in calculating image reconstruction data; and c) performing a reconstruction data calculation using said CT projection data defined by said projection data mask and said reconstruction mask to obtain image reconstruction data for reconstruction of a CT image, wherein the calculation uses the image mask and an image center as one boundary, and wherein said iterative reconstruction data calculation comprises solving an equation in the form of: for n=0 to a finite number of iterations, and where λ n+1 is the calculated estimate of the image, λ n is the previously calculated estimate of the image, λ 0 is the original CT image, m is the image mask, N is the normalized projection data mask, y is the measured projection data, BP is the back projection operator, and FP is the forward projection operator.