Patent ID: 6418184
Filing Date: 2002-07-09
Classification: A61B,Y10S

Abstract:
A method for reconstructing an image of an object utilizing a computed tomographic (CT) imaging system having a radiation source and a multislice detector array on a rotating gantry, the radiation source configured to project a beam of radiation through an object and towards the multislice detector array, the multislice detector array configured to sense attenuation of the radiation passing through the object;said method comprising the steps of: helically scanning an object with a computed tomographic imaging system to acquire a plurality of slices of projection data; interpolating an axial fan beam set of projection data as a vector function {right arrow over (R)}a from a fan beam set of projection data from the helical scan {right arrow over (R)}hi, where i=1, . . . , n is a row index and n represents a of number of rows of the detector array, using a relationship written as: R&RightArrow;a&it;(Î²,Î³)=&Sum;i=1n&it;wi&it;(Î²)&it;R&RightArrow;hi&it;(Î²,Î³),where wi(&bgr;) is a weighting function written as: wi=&Sum;j=1m&it;f&it;â€ƒ&it;(Î²-Î²j),where m is a number of images used for z smoothing, &bgr;j is a gantry rotation angle for a plane of reconstrution of a jth image, and f&it;â€ƒ&it;(x)={g&it;â€ƒ&it;(x),&LeftBracketingBar;x&RightBracketingBar;&leq;Î²b0,&LeftBracketingBar;x&RightBracketingBar;>Î²bwhere constants Î²b=2&it;â€ƒ&it;Ï€p,â€ƒand g(x) is either a linear or non-linear function.