Method for image processing and reconstruction of images for optical tomography
First Claim
Patent Images
1. A method for reconstructing three-dimensional (3D) tomographic images comprising:
- acquiring a set of pseudo-projection images of at least one object;
applying error corrections to the set of pseudo-projection images to produce a set of corrected pseudo-projection images, where the error corrections correct for registration error effects by measuring a center of mass of the at least one object in each projection image, and by correcting for axial registration errors by shifting the at least one object in each pseudo-projection image so that the axial component of the center of mass for the object is aligned to a common axial position in each of the set of corrected pseudo-projection images; and
processing the set of corrected pseudo-projection images to produce (3D) tomographic images.
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Abstract
A method for reconstructing three-dimensional (3D) tomographic images. A set of pseudo-projection images of an object is acquired. Error corrections are applied to the set of pseudo-projection images to produce a set of corrected pseudo-projection images. The set of corrected pseudo-projection images are processed to produce (3D) tomographic images.
140 Citations
57 Claims
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1. A method for reconstructing three-dimensional (3D) tomographic images comprising:
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acquiring a set of pseudo-projection images of at least one object; applying error corrections to the set of pseudo-projection images to produce a set of corrected pseudo-projection images, where the error corrections correct for registration error effects by measuring a center of mass of the at least one object in each projection image, and by correcting for axial registration errors by shifting the at least one object in each pseudo-projection image so that the axial component of the center of mass for the object is aligned to a common axial position in each of the set of corrected pseudo-projection images; and processing the set of corrected pseudo-projection images to produce (3D) tomographic images. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method for reducing registration errors in a projection image comprising:
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a) acquiring at least a pair of projection images, wherein the at least a pair of projection images are extended depth of field images; a) measuring the center of mass of at least one object of interest in each projection image; b) correcting for axial registration errors by shifting each projection image so that the axial component of the center of mass in each projection image is aligned to a common axial position; and c) correcting for centering errors by shifting each projection image so that the vertical component of the center of mass in each projection image is aligned to the centerline of the image. - View Dependent Claims (29)
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30. A method for reducing registration errors in a projection image comprising:
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(a) acquiring at least one pair of projection images at opposing viewing angles, wherein the at least one pair of projection images are extended depth of field images; (b) applying a shift to a member of the at least one pair of projection images at opposing viewing angles, relative to the other member; (c) combining the shifted member and the other member to produce combined shifted projection images; (d) measuring the combined shifted projection images to determine if registration errors are a minimum for at least one of registration errors including centering errors and axial registration errors; and (e) repeating steps (b) through (d) until step (d) is true. - View Dependent Claims (31, 32, 33, 34, 35)
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36. A method for reducing reconstruction errors due to the illumination variation in a series of pseudo-projection images comprising:
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(a) lighting an object in an illumination region to produce a series of pseudo-projection images at varying positions along an optical axis; and (b) altering each pseudo-projection image'"'"'s grey scale value proportionate to an illumination gradient representing a change of grey scale values for locations along the optical axis, wherein each of the series of pseudo-projection images has a corrected illumination level estimated from a priori knowledge and knowledge of the position of the optical elements during acquisition of the pseudo-projection image. - View Dependent Claims (37, 38, 39, 40)
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41. A method for generating 3D images from an optical tomography system, where the optical tomography system includes an optical axis comprising:
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dividing a full projection scan of an object into a plurality of sectional pseudo-projections acquired at a plurality of perspective viewing angles, where the sectional pseudo-projections are divided into sections located along the optical axis and wherein each of the plurality of sectional pseudo-projections includes at least two outer sections and a middle section, the method further comprising weighting the at least two outer sections at a lower value than the middle section; summing the plurality of sectional pseudo-projections at each of the plurality of perspective viewing angles to form a set of full pseudo-projections; and backprojecting the set of full pseudo-projections in a volume of reconstruction to form a 3D reconstruction of the object. - View Dependent Claims (42)
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43. A method for generating 3D images from an optical tomography system comprising:
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dividing a full projection scan of an object into a plurality of sectional pseudo-projections acquired at a plurality of perspective viewing angles, where the sectional pseudo-projections are divided into sections located along the optical axis, wherein the plurality of sectional pseudo-projections includes at least two outer sections and a middle section, the method further comprising weighting the at least two outer sections at a lower value than the middle section; and backprojecting the plurality of sectional pseudo-projections in a volume of reconstruction for forming a 3D reconstruction of the object. - View Dependent Claims (44, 45, 46, 47)
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48. A method for scanning an object moving in an axial direction transverse to an objective scanning direction comprising:
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scanning an objective lens through the object in the objective scan direction; measuring in-plane spatial frequency power spectra as a function of the location of the focal plane relative to the center of the object, wherein measuring in-plane spatial frequency power spectra comprises; (a) imaging the object by scanning a focal plane to find a peak focus score; (b) acquiring an image stack through the object relative to a center, where the center is defined as a peak focus score; (c) calculating an in-plane spatial frequency power spectrum of each image in the stack; (d) repeating steps (a) through (d) for a plurality objects; (e) calculating in-plane spatial frequency power spectra for the plurality of objects to determine an average in-plane spatial frequency power spectrum for each location relative to the center; and sectioning the scanned pseudo-projection. - View Dependent Claims (49, 50)
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51. A method for generating a statistical filter for reconstruction of images for 3D reconstructions, the method comprising:
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creating a set of virtual phantoms; computing a phantom FFT of each phantom in the set of virtual phantoms to produce a set of phantom FFTs; creating a plurality of simulated pseudo-projections of the set of virtual phantoms from various perspectives; backprojecting the plurality of simulated pseudo-projections to form a 3D reconstruction; computing an FFT of the 3D reconstruction; and creating a filter using a ratio of a subset of the set of phantom FFTs to the FFT of the 3D reconstruction expressed by the set of backprojections. - View Dependent Claims (52, 53)
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54. A method of 3D reconstruction comprising:
computing backprojection values within a sub-volume of the volume of reconstruction where 3D spatial coordinates and dimensions of the sub-volume are computed by determination of bounding box parameters for two orthogonal views of the reconstruction volume, wherein determination of bounding box parameters comprises; analyzing a first pseudo-projection (PP) at 0°
by finding the edges of the region of interest to determine a bounding box from a first perspective;finding a set of coordinates X0, Z0 in PP space; finding a set of coordinates Xr, Zr in reconstruction space; analyzing PP@90°
by finding the edges of the region of interest to determine a bounding box from a second perspective;finding a set of coordinates X90, Z90 in PP space; finding a set of coordinates Yr in reconstruction space; and reconstructing volume using a set of coordinates [Xr, Yr, Zr]. - View Dependent Claims (55, 56, 57)
Specification