Data reduction in reprojection systems

Claim 2

An arrangement for improving the processing time for systems that include reprojection means, said reprojection means reprojecting initial image data to obtain reprojections for use in correcting for polychromatic artifacts in diagnostic medical images of a subject, said arrangement comprising: (a) scanning means for directing radiation through said subject and detecting an intensity distribution of the radiation traversing the subject; (b) means for providing a set of original projections derived from the detected intensity distribution; (c) back-projector means for back-projecting said set of original projections to provide an original amount of initial image data for an initial image; (d) image processor means for processing a reduced amount of said initial image data into initial image correcting data based on at least two or more constituent tissues having different energy dependent radiation attenuation characteristics; (e) reprojector means for converting a reduced amount of said initial image correcting data into correcting reprojections; (f) means separate from said reprojector means for reducing the original amount of initial image data supplied to said image processor means to speed up the correction operations of said image processor and said reprojector while maintaining the original amount of initial image data; and (g) correction means for connecting said correcting reprojections to said back-projector means to provide image correcting data to correct said initial image data and to thereby provide corrected image data having reduced polychromatic artifact data but having an unreduced amount of image data equal to the amount in said initial image.

Claim 3

An arrangement for improving the processing time for systems that include reprojector means, said reprojector means reprojecting image data to obtain reprojections for use in correcting for polychromatic artifacts in diagnostical medical images of a subject, said arrangement comprising: (a) scanning means for directing radiation through said subject and detecting an intensity distribution of the radiation traversing the subject; (b) means for providing a set of original projections derived from the detected intensity distribution; (c) back-projector means for back-projecting said set of original projections to provide an original amount of initial image data for an initial image; (d) image processor means for processing a reduced amount of said original amount of initial image data into reduced initial image correcting data based on at least two constituent tissues having different energy dependent radiation attenuation characteristics; (e) reprojector means for converting said reduced image correcting data into correcting reprojections; (f) means separate from said reprojector means for reducing the initial image data supplied to said image processor means to speed up the operation of said image processor and reprojector means during the correction process while maintains the original amount of initial image data for use in the image display; (g) correction means for combining said correcting reprojections and said set of original projections to provide a set of corrected projections, having the same number of projections as said set of original projections; and (h) means for connecting said set of corrected projections to said back-projector means to provide image correcting data having the original amount of initial image data to correct said initial image data.

Claim 4

An arrangement for improving the processing time for systems that include reprojector means, said reprojector means reprojecting image data to obtain reprojections for use in correcting for polychromatic artifacts in diagnostical medical images of a subject, said arrangement comprising: (a) scanning means for directing radiation through said subject and detecting an intensity distribution of the radiation traversing the subject; (b) means for providing a set of original projections derived from the detected intensity distribution; (c) back-projector means for back-projecting said set of original projections to provide an original amount of initial image data for an initial image; (d) image processor means for processing a reduced amount of said original amount of initial image data into reduced initial image correcting data based on at least two constituent tissues having different energy dependent radiation attenuation characteristics; (e) reprojector means for converting said reduced image correcting data into correcting reprojections; (f) means separate from said reprojector means for reducing the initial image data supplied to said image processor means to speed up the operation of said image processor and reprojector means during the correction process while maintains the original amount of initial image data for use in the image display; (g) correction means for combining said correcting reprojections and said set of original projections to provide a set of corrected projections, having the same number of projections as said set of original projections; and (h) means for connecting said set of corrected projections to said back-projector means to provide image correcting data having the original amount of initial image data to correct said initial image data.

Claim 7

An arrangement for improving the processing time of systems that include reprojector means for generating reprojections used to reduce polychromatic artifacts in computerized tomographically (CT) produced images of a subject, said arrangement comprising: (a) means for directing radiation through said subject; (b) means for detecting a radiation intensity distribution of the radiation traversing the subject; (c) means for providing a set of original projections derived from the detected radiation intensity distribution; (d) means for selecting only certain projections of said set of original projections; (e) back-projector means for back projecting said selected certain projections of said set of original projections to provide a correction image having reduced data; (f) means for processing said correction image to provide correction data; (g) means for reprojecting said correction data to provide correction reprojections; (h) means for combining said correction reprojections and said projections to provide a set of corrected projections having substantially the same number of projections as said set of original projections; and (i) means for connecting said set of corrected projections to said back projector means to provide a corrected image.

Claim 8

An arrangement for improving the processing time of systems that include reprojector means for generating reprojections used to reduce polychromatic artifacts in computerized tomographically (CT) produced images of a subject, said arrangement comprising: (a) means for directing radiation through said subject; (b) means for detecting a radiation intensity distribution of the radiation traversing the subject; (c) means for providing a set of original projections derived from the detected radiation intensity distribution; (d) means for selecting only certain projections of said set of original projections; (e) back-projector means for back projecting said selected certain projections of said set of original projections to provide a correction image having reduced data; (f) means for processing said correction image to provide correction data; (g) means for reprojecting said correction data to provide correction reprojections; (h) means for combining said correction reprojections and said projections to provide a set of corrected projections having substantially the same number of projections as said set of original projections; and (i) means for connecting said set of corrected projections to said back projector means to provide a corrected image.

Claim 11

An arrangement for improving the processing time of systems that include reprojector means for generating reprojections used to reduce polychromatic artifacts in computerized tomographically (CT) produced images of a subject, said arrangement comprising: (a) means for directing radiation through said subject; (b) means for detecting a radiation intensity distribution of the radiation traversing the subject; (c) means for providing a set of original projections derived from said detected radiation intensity distribution; (d) back-projecting means for back projecting said set of original projections to form initial image data; (e) image processor means including data compression means for providing compressed image correcting data; (f) reprojector means for providing compressed image correcting reprojections; (g) means for connecting said compressed image correcting reprojections to said back projector means to obtain compressed image correction data; (h) means for expanding said compressed image correction data to provide image correction data; and (i) means for combining said image correction data and said image data to provide a corrected image.

Claim 12

An arrangement for improving the processing time of systems that include reprojector means for generating reprojections used to reduce polychromatic artifacts in computerized tomographically (CT) produced images of a subject, said arrangement comprising: (a) means for directing radiation through said subject; (b) means for detecting a radiation intensity distribution of the radiation traversing the subject; (c) means for providing a set of original projections derived from said detected radiation intensity distribution; (d) back-projecting means for back projecting said set of original projections to form initial image data; (e) image processor means including data compression means for providing compressed image correcting data; (f) reprojector means for providing compressed image correcting reprojections; (g) means for connecting said compressed image correcting reprojections to said back projector means to obtain compressed image correction data; (h) means for expanding said compressed image correction data to provide image correction data; and (i) means for combining said image correction data and said image data to provide a corrected image.