System for reprojecting images using transform techniques

Claim 1

A system for reprojecting images comprising: means for detecting radiation attenuated by passing through a subject, means for preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, means for filtering said data to obtain filtered data, means for backprojecting said filtered data to obtain digital images, feedback for feeding back said digital images, means for taking the two dimensional Fourier transforms of the image in the feedback means, means for obtaining the values of the Fourier transforms of the image along radial lines using interpolation, and means for forming the one-dimensional inverse Fourier transform of the radial lines to obtain data corresponding to reprojections.

Claim 2

A system for reprojecting images comprising: means for detecting radiation attenuated by passing through a subject, means for preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, means for filtering said data to obtain filtered data, means for backprojecting said filtered data to obtain digital images, feedback for feeding back said digital images, means for taking the two dimensional Fourier transforms of the image in the feedback means, means for obtaining the values of the Fourier transforms of the image along radial lines using interpolation, and means for forming the one-dimensional inverse Fourier transform of the radial lines to obtain data corresponding to reprojections.

Claim 5

A system for correcting for artifacts in images obtained in computerized tomographic devices said system comprising: means for detecting radiation attenuated by passing through a subject, means for preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, means for filtering said data, means for back projecting said filtered data to obtain digital images, feedback loop means including reprojection means using said digital image for obtaining correction data, said feedback loop means including Fourier transform calculating means, and means for combining said correction data to said preprocessed data to correct artifacts in said image.

Claim 6

A system for correcting for artifacts in images obtained in computerized tomographic devices said system comprising: means for detecting radiation attenuated by passing through a subject, means for preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, means for filtering said data, means for back projecting said filtered data to obtain digital images, feedback loop means including reprojection means using said digital image for obtaining correction data, said feedback loop means including Fourier transform calculating means, and means for combining said correction data to said preprocessed data to correct artifacts in said image.

Claim 8

A method of reprojecting images including the steps of: detecting radiation attenuated by passing through a subject, obtaining data corresponding to projections of said detected radiation, filtering said data, backprojecting the filtered date to obtain a digitized image, feeding back said digitized image, taking the two-dimensional Fourier transform of the image during the feedback step, interpolating the two-dimensional Fourier transform of the image to obtain values of the transform along radial lines, and forming the one-dimensional inverse Fourier transform of the radial lines to obtain reprojection data for said image.

Claim 9

A method of reprojecting images including the steps of: detecting radiation attenuated by passing through a subject, obtaining data corresponding to projections of said detected radiation, filtering said data, backprojecting the filtered date to obtain a digitized image, feeding back said digitized image, taking the two-dimensional Fourier transform of the image during the feedback step, interpolating the two-dimensional Fourier transform of the image to obtain values of the transform along radial lines, and forming the one-dimensional inverse Fourier transform of the radial lines to obtain reprojection data for said image.

Claim 13

A method for correcting for artifacts in images obtained in computerized tomographic devices, said method including the steps of: detecting radiation attenuated by passing through a subject, preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, filtering said data, backprojecting the filtered data to obtain a digitized image, feeding back said digitized image, taking the two-dimensional Fourier transform of the image during the feed-back step, interpolating the transform of the image to obtain the values of the transform along radial lines, forming the one-dimensional inverse Fourier transform of the radial lines to obtain reprojections, combining said reprojections with the data corresponding to projections, and filtering and backprojecting the combined data to form a corrected image.

Claim 14

A method for correcting for artifacts in images obtained in computerized tomographic devices, said method including the steps of: detecting radiation attenuated by passing through a subject, preprocessing said detected radiation to obtain data corresponding to projections of said detected radiation, filtering said data, backprojecting the filtered data to obtain a digitized image, feeding back said digitized image, taking the two-dimensional Fourier transform of the image during the feed-back step, interpolating the transform of the image to obtain the values of the transform along radial lines, forming the one-dimensional inverse Fourier transform of the radial lines to obtain reprojections, combining said reprojections with the data corresponding to projections, and filtering and backprojecting the combined data to form a corrected image.