IMAGE-BASED MATERIAL DECOMPOSITION
First Claim
Patent Images
1. An imaging apparatus having a data acquisition system configured to reconstruct an image of an object and comprising a computer programmed to:
- define a given projection into a first segment and a second segment different from the first segment;
acquire a first set of data in the first segment and acquire a second set of data in the second segment, wherein the first set of data is acquired at a first energy level and the second set of data is acquired at a second energy level that is different from the first energy level;
reconstruct a first image from the first set of data and a second image from the second set of data;
re-project the first image to a first set of corrected sinograms and re-project the second image to a second set of corrected sinograms;
decompose the first and second sets of corrected sinograms and determine atomic number information for each ray of each corrected sinogram, wherein the step of decomposing comprises generating an atomic number of material composition map from the decomposition;
reconstruct a first corrected image and a second corrected image from the first and the second sets of corrected sinograms; and
automatically register the first and the second corrected images into a composite image substantially free of beam hardening artifacts, wherein the composite image provides material decomposition information.
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Abstract
A CT scanner acquires CT images at different energy levels and registers those images to provide a composite image that is substantially free of beam hardening artifacts and conspicuously provides atomic information of that imaged.
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Citations
27 Claims
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1. An imaging apparatus having a data acquisition system configured to reconstruct an image of an object and comprising a computer programmed to:
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define a given projection into a first segment and a second segment different from the first segment;
acquire a first set of data in the first segment and acquire a second set of data in the second segment, wherein the first set of data is acquired at a first energy level and the second set of data is acquired at a second energy level that is different from the first energy level;
reconstruct a first image from the first set of data and a second image from the second set of data;
re-project the first image to a first set of corrected sinograms and re-project the second image to a second set of corrected sinograms;
decompose the first and second sets of corrected sinograms and determine atomic number information for each ray of each corrected sinogram, wherein the step of decomposing comprises generating an atomic number of material composition map from the decomposition;
reconstruct a first corrected image and a second corrected image from the first and the second sets of corrected sinograms; and
automatically register the first and the second corrected images into a composite image substantially free of beam hardening artifacts, wherein the composite image provides material decomposition information. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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2. (canceled)
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20. A computer readable storage medium having a computer program stored thereon and representing a set of instructions that when executed by a computer causes the computer to perform image-based atomic number mapping of an object imaged in a dual-energy mode, wherein the set of instructions comprise:
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defining a given projection into a first segment and a second segment different from the first segment;
acquiring a first set of data in the first segment and acquiring a second set of data in the second segment, wherein the first set of data is acquired at a first energy level and the second set of data is acquired at a second energy level that is different from the first energy level;
reconstructing a first image from the first set of data and a second image from the second set of data;
re-projecting the first image to a first set of corrected sinograms and re-projecting the second image to a second set of corrected sinograms;
decomposing the first and second sets of corrected sinograms and determining atomic number information for each ray of each corrected sinogram, wherein the step of decomposing comprises generating an atomic number of material composition map from the decomposition;
reconstructing a first corrected image and a second corrected image from the first and the second sets of corrected sinograms; and
automatically registering the first and the second corrected images into a composite image substantially free of beam hardening artifacts, wherein the composite image provides material decomposition information. - View Dependent Claims (21, 22)
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23. A method of CT imaging comprising the steps of:
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determining a thickness for each pixel;
determining a first attenuation coefficient for a given pixel in a first image;
determining a second attenuation coefficient, different from the first attenuation coefficient, for the given pixel in a second image different from the first image;
determining a linear coefficient ratio between the first attenuation coefficient and the second attenuation coefficient;
determining an atomic make-up for the given pixel from the linear coefficient ratio, wherein the thickness determined for each pixel mitigates beam hardening artifacts for the pixel; and
displaying a registered image comprised of the first and the second images with the given pixel in the registered image displayed in a conspicuous manner to indicate the atomic make-up of that imaged in the given pixel. - View Dependent Claims (24, 25, 26, 27)
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Specification