Patent ID: 6256404
Filing Date: 2001-07-03
Classification: G01V

Abstract:
A method of scanning each of a plurality of different objects sequentially transported through a CT scanning machine such that each object is scanned within a field of view of the CT scanning machine, comprising:scanning each object within the field of view so as to generate the scan data for the entire field of view at a predetermined resolution;determining the size, shape and location of the object within the field of view including determining the number of pixels required to produce a computed tomographic image of the cross-sectional area of the object, and whether the number of pixels required to reproduce a computed tomographic image of the cross-sectional area of the object exceeds a predetermined limit;choosing one of a plurality of predetermined sub-fields of view, each disposed within and smaller in cross-sectional area than the field of view, which best corresponds to said object size and object shape; andreconstructing the pixels that comprise the chosen sub-field of view at said object location with the predetermined resolution using the relevant scan data and computed tomographic image reconstruction techniques so as to produce a pixelated image of the sub-field of view within a predefined pixel window corresponding to a reconstruction window area;wherein (a) all of the pixels required to produce the pixelated computed tomographic image of the cross-sectional area of the object are reconstructed within a pixel window corresponding to the predefined reconstruction window area when the number of pixels required to reproduce the computed tomographic image is less than or equal to the predetermined limit; and (b) the predetermined limited number of pixels required to produce the computed tomographic image of that portion of the cross-sectional area of the object within a predefined reconstruction area making a fit to the best possible pixel window when the number of pixels required to reproduce the computed tomographic image is greater than the predetermined limit.