DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-4, 6-13, and 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over Sharma et al., “Interior micro-CT with an offset detector” (Sharma), and further in view of Schafer, US 2020/0085389 A1 (Schafer).
Regarding claim 1, Sharma teaches a method for reconstructing a sample from projection data (methods for reconstructing a sample from projection data) (p. 3; Fig. 2) obtained by a single rotation wide field mode (SRWFM) X-ray- microscopy tomographic scan (microcomputed tomography (micro-CT), using an x-ray tube, that acquires projections over 360 degrees with an offset to increase the FOV (field of view)) (p. 1; Section 1., 1st paragraph and p. 2; left column, 1st paragraph) (p. 5; Fig. 3), the method comprising:
acquiring, by a detector (a flat panel x-ray detector) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph), X-ray projections (x-ray projections from the x-ray source) (p. 2; left col., 1st paragraph and Fig. 1) (p. 5; Fig. 3) of the sample (the sample) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph) by rotating the sample about a rotation axis (wherein the sample is rotated on a stage during data acquisition) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph) that is offset with respect to an X-ray propagation axis (wherein the detector is offset; and thus the x-ray propagation is offset from the sample) (p. 1; Section “Purpose”) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph); and
Method I: Preconvolution weighting:
processing the acquired projections to account for the offset rotation axis by applying redundancy weighting (the weighting function is used to fix the data redundancy of the projection/sinogram) (pages 2-3; Section 2.A.1. Method I and Fig. 2) to correct for incomplete angular sampling in regions of the projection data (to correct the sampling in regions; the asymmetry (coverage of the object at different projection angles) must be accounted for during reconstruction using a weighting scheme) (pages 1-2; Section 1., 2nd paragraph),
wherein the redundancy weighting is performed before back-projection in an analytical reconstruction or before an equivalent back-projection operation in an iterative reconstruction (wherein the weighting in step (c) is done before the filtered backprojection) (pages 2-3; Section 2.A.1. Method I and Fig. 2).
Method II: Postconvolution weighting:
processing the acquired projections to account for the offset rotation axis by applying redundancy weighting (the weighting function is used to fix the data redundancy of the projection/sinogram) (pages 2-4; Section 2.A.1., Equation 2, Fig. 2, and Section 2.A.2. Method II) to correct for incomplete angular sampling in regions of the projection data (to correct the sampling in regions; the asymmetry (coverage of the object at different projection angles) must be accounted for during reconstruction using a weighting scheme) (pages 1-2; Section 1., 2nd paragraph),
wherein the redundancy weighting is performed before back-projection in an analytical reconstruction or before an equivalent back-projection operation in an iterative reconstruction (wherein the weighting in step (i) is done before backprojection) (pages 3-4; Fig. 2 and Section 2.A.2. Method II).
In Methods I and II Sharma teaches using a weighting function to fix the data redundancy of the projection/sinogram (pages 2-3; Section 2.A.1. Method I and Fig. 2). Although “redundancy weighting” isn’t specifically stated in Methods I and II, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that since the weighting is used to fix “the data redundancy” that “redundancy weighting” is being used. Also, it would have been obvious since Sharma explicitly teaches using a type of “redundancy weighting” in Method III, as a way to modify Equation 2 used in Methods I and II (p. 4; Section 2.A.3. Method III).
However, Sharma does not explicitly state reconstructing “a three-dimensional volume” of a sample.
Schafer teaches an off-center detector X-ray tomography reconstruction of an image of an object on the basis of projection data acquired (Abstract); wherein a three-dimensional image of an object in an extended field-of-view can be reconstructed ([0011] and [0037]); and wherein in order to avoid related image artifacts, a redundancy weighting also has to be carried out in this acquisition scheme ([0011] and [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Sharma to include using the reconstruction technique for three-dimensional imaging since it increases the modality of the system as well as allows for an accurate image reconstruction can be carried out and the image reconstruction can start during the scan, so that the reconstructed image is available quickly after completion of the scan (Schafer; [0017] and [0041]).
Regarding claim 2, Sharma teaches further comprising, prior to the redundancy weighting (prior to the weighting function) (pages 3-4; Fig. 2 and Section 2.A.2., step e.), applying a ramp filter to the projection data (applying a ramp filter to the projection data) (p. 3; Fig. 2, steps (h) and (i)) (pages 3-4; Section 2.A.2., step d.), wherein the redundancy weighting is performed on the ramp-filtered data (wherein the weighting function is performed on the ramp filtered data) (p. 3; Fig. 2, steps (h) and (i)) (pages 3-4; Section 2.A.2., step e.).
Regarding claim 3, Sharma teaches wherein the redundancy weighting is applied in a region around a projection of the rotation axis on the detector (wherein the weighting is applied in a region around the projection on the detector) (pages 2-3; Section 2.A.1., step b.) (p. 3; Fig. 2) (pages 3-4; Section 2.A.2., step e.).
Regarding claim 4, Sharma teaches wherein the redundancy weighting employs a position-dependent weighting function that corrects for projections (wherein the weighting is position dependent (distance, angular position, spatial and angular positions of the detector) are all used within the weighting function) (p. 2; Section 2.A.) (pages 2-3; Section 2.A.1., step b.) (p. 3; Fig. 2) (pages 3-4; Section 2.A.2., step e.) without requiring multiple scans (wherein the sinograms have 360 degree angular coverage) (p. 3; Fig. 2) (wherein the weighting scheme accounts for the fact that a central overlapping region is sampled over the entire 360 degree) (pages 1-2; Section 1., 2nd paragraph).
Regarding claim 6, Sharma teaches wherein the projections are remapped onto a virtual detector plane connecting the X-ray source and the rotation axis (wherein the system can due numerical phantom simulation with the detector offset and 720 projections were acquired over 360 degrees) (pages 4-5; Section 2.B.1.), thereby ensuring correct attenuation coefficient representation in the reconstructed volume (intended use) (pages 4-5; Section 2.B.1.).
However, Sharma does not explicitly teach a detector plane “perpendicular to a line” connecting the X-ray source and the rotation axis, and “reconstructed volume”.
Schafer teaches an off-center detector X-ray tomography reconstruction of an image of an object on the basis of projection data acquired (Abstract); wherein a three-dimensional image of an object in an extended field-of-view can be reconstructed ([0011] and [0037]); and wherein a detector plane perpendicular to a line connecting the X-ray source and the rotation axis (detector array of the detector is positioned asymmetrically with respect to the central ray of the beam passing through the isocenter, in a direction perpendicular to the direction of the central ray; and the detector offset, which may be parameterized by the displacement D between the middle 205 of the X-ray detector 2 and the central ray 202 of the X-ray beam, can preferably be controlled by displacing the detector array relative to X-ray source 1 until the desired detector offset is achieved) (Fig. 2; [0039]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Sharma to include using the reconstruction technique for three-dimensional imaging since it increases the modality of the system, allows for the desired detector offset (Shafer; [0039]), as well as allows for an accurate image reconstruction can be carried out and the image reconstruction can start during the scan, so that the reconstructed image is available quickly after completion of the scan (Schafer; [0017] and [0041]).
Regarding claim 7, Sharma teaches wherein the iterative reconstruction approach (weighted iterative reconstruction) (p. 4; Section 2.A.3. Method III) includes applying a noise model-based weighting (applying a splicing technique to ensure smooth merging) (p. 4; Section 2.A.3. Method III) to the difference between measured and forward-projected data (difference between measured and forward-projected data) (p. 4; Section 2.A.3. Method III), and subsequently incorporating the redundancy weighting before back-projection (performing redundancy weighting before back-projection) (p. 3; Fig. 2 and p. 4; Section 2.A.3. Method III), thus improving noise handling and artifact reduction (intended use; projection correction) (p. 4; Section 2.A.3. Method III).
Regarding claim 8, Sharma teaches further comprising acquiring projections over a full 360- degree rotation of the sample to ensure sufficient sampling of regions within the enlarged field of view (by offsetting the detector, and acquiring projections over 360°, the effective FOV is larger than the original FOV without detector offset) (p. 2; left column, 1st paragraph).
Regarding claim 9, Sharma teaches further comprising acquiring projections only over a single full 360-degree rotation (by offsetting the detector, and acquiring projections over 360°, the effective FOV is larger than the original FOV without detector offset) (p. 2; left column, 1st paragraph).
Regarding claim 10, Sharma teaches a system (micro-CT system) (p. 5; Fig. 3) for reconstructing a sample from projection data (for reconstructing a sample from projection data) (p. 3; Fig. 2) obtained by a single rotation wide field mode (SRWFM) X-ray scan (microcomputed tomography (micro-CT), using an x-ray tube, that acquires projections over 360 degrees with an offset to increase the FOV (field of view)) (p. 1; Section 1., 1st paragraph and p. 2; left column, 1st paragraph) (p. 5; Fig. 3), the system comprising:
an X-ray source configured to generate an X-ray beam (an x-ray source for creating an x-ray beam) (p. 2; Fig. 1 and p. 5; Fig. 3) (x-ray projections from the x-ray source) (p. 2; left col., 1st paragraph and Fig. 1) (p. 5; Fig. 3);
a rotation stage (motorized rotation stage) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph) configured to hold and rotate the sample about a rotation axis (wherein the sample is rotated on a stage during data acquisition) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph) offset with respect to an X-ray propagation axis (wherein the detector is offset; and thus the x-ray propagation is offset from the sample) (p. 1; Section “Purpose”) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph), thereby providing X-ray projections with an enlarged effective field of view beyond nominal detector dimensions (acquires projections over 360 degrees with an offset to increase the FOV (field of view)) (p. 2; Fig. 1 and left column, 1st paragraph);
a detector configured to receive the X-ray projections of the sample (a detector array to receive the x-ray projections) (p. 2; Fig. 1 and p. 5; Fig. 3); and
a processing system (computer and micro-CT) (p. 8; Section 4., 1st paragraph) configured to:
receive projection data (x-ray projections from the x-ray source) (p. 2; left col., 1st paragraph and Fig. 1) (p. 5; Fig. 3) from the detector (a flat panel x-ray detector) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph),
Method I: Preconvolution weighting:
apply redundancy weighting (the weighting function is used to fix the data redundancy of the projection/sinogram) (pages 2-3; Section 2.A.1. Method I and Fig. 2) to correct for incomplete angular sampling in regions of the projection data (to correct the sampling in regions; the asymmetry (coverage of the object at different projection angles) must be accounted for during reconstruction using a weighting scheme) (pages 1-2; Section 1., 2nd paragraph),
wherein the redundancy weighting is performed before back-projection in an analytical reconstruction or before an equivalent back-projection operation in an iterative reconstruction (wherein the weighting in step (c) is done before the filtered backprojection) (pages 2-3; Section 2.A.1. Method I and Fig. 2), and
reconstruct the sample from the projection data based on the applied redundancy weighting (wherein the first method reconstructs the sample using the projection data based on a weighting scheme) (pages 2-3; Section 2.A.1. Method I and Fig. 2).
Method II: Postconvolution weighting:
apply redundancy weighting (the weighting function is used to fix the data redundancy of the projection/sinogram) (pages 2-4; Section 2.A.1., Equation 2, Fig. 2, and Section 2.A.2. Method II) to correct for incomplete angular sampling in regions of the projection data (to correct the sampling in regions; the asymmetry (coverage of the object at different projection angles) must be accounted for during reconstruction using a weighting scheme) (pages 1-2; Section 1., 2nd paragraph),
wherein the redundancy weighting is performed before back-projection in an analytical reconstruction or before an equivalent back-projection operation in an iterative reconstruction (wherein the weighting in step (i) is done before backprojection) (pages 3-4; Fig. 2 and Section 2.A.2. Method II), and
reconstruct the sample from the projection data based on the applied redundancy weighting (wherein the second method reconstructs the sample using the projection data based on a weighting scheme) (pages 3-4; Fig. 2 and Section 2.A.2. Method II).
In Methods I and II Sharma teaches using a weighting function to fix the data redundancy of the projection/sinogram (pages 2-3; Section 2.A.1. Method I and Fig. 2). Although “redundancy weighting” isn’t specifically stated in Methods I and II, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that since the weighting is used to fix “the data redundancy” that “redundancy weighting” is being used. Also, it would have been obvious since Sharma explicitly teaches using a type of “redundancy weighting” in Method III, as a way to modify Equation 2 used in Methods I and II (p. 4; Section 2.A.3. Method III).
However, Sharma does not explicitly state reconstructing “a three-dimensional volume” of a sample.
Schafer teaches an off-center detector X-ray tomography reconstruction of an image of an object on the basis of projection data acquired (Abstract); wherein a three-dimensional image of an object in an extended field-of-view can be reconstructed ([0011] and [0037]); and wherein in order to avoid related image artifacts, a redundancy weighting also has to be carried out in this acquisition scheme ([0011] and [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Sharma to include using the reconstruction technique for three-dimensional imaging since it increases the modality of the system as well as allows for an accurate image reconstruction can be carried out and the image reconstruction can start during the scan, so that the reconstructed image is available quickly after completion of the scan (Schafer; [0017] and [0041]).
Regarding claim 11, Sharma teaches wherein the processing system is further configured to apply a ramp filter to the projection data (applying a ramp filter to the projection data) (p. 3; Fig. 2, steps (h) and (i)) (pages 3-4; Section 2.A.2., step d.) prior to applying the redundancy weighting (prior to the weighting function) (pages 3-4; Fig. 2 and Section 2.A.2., step e.), such that the redundancy weighting is performed on the ramp-filtered data (wherein the weighting function is performed on the ramp filtered data) (p. 3; Fig. 2, steps (h) and (i)) (pages 3-4; Section 2.A.2., step e.).
Regarding claim 12, Sharma teaches wherein the processing system is configured to apply the redundancy weighting in a region around a projection of the rotation axis on the detector (wherein the weighting is applied in a region around the projection on the detector) (pages 2-3; Section 2.A.1., step b.) (p. 3; Fig. 2) (pages 3-4; Section 2.A.2., step e.).
Regarding claim 13, Sharma teaches wherein the processing system is configured to employ a position-dependent weighting function that corrects for projections (wherein the weighting is position dependent (distance, angular position, spatial and angular positions of the detector) are all used within the weighting function) (p. 2; Section 2.A.) (pages 2-3; Section 2.A.1., step b.) (p. 3; Fig. 2) (pages 3-4; Section 2.A.2., step e.) without requiring multiple scans (wherein the sinograms have 360 degree angular coverage) (p. 3; Fig. 2) (wherein the weighting scheme accounts for the fact that a central overlapping region is sampled over the entire 360 degree) (pages 1-2; Section 1., 2nd paragraph).
Regarding claim 15, Sharma teaches wherein the processing system is configured to remap the projections onto a virtual detector plane connecting the X-ray source and the rotation axis (wherein the system can due numerical phantom simulation with the detector offset and 720 projections were acquired over 360 degrees) (pages 4-5; Section 2.B.1.), thereby ensuring correct attenuation coefficient representation in the reconstructed volume (intended use) (pages 4-5; Section 2.B.1.).
However, Sharma does not explicitly teach a detector plane “perpendicular to a line” connecting the X-ray source and the rotation axis, and “reconstructed volume”.
Schafer teaches an off-center detector X-ray tomography reconstruction of an image of an object on the basis of projection data acquired (Abstract); wherein a three-dimensional image of an object in an extended field-of-view can be reconstructed ([0011] and [0037]); and wherein a detector plane perpendicular to a line connecting the X-ray source and the rotation axis (detector array of the detector is positioned asymmetrically with respect to the central ray of the beam passing through the isocenter, in a direction perpendicular to the direction of the central ray; and the detector offset, which may be parameterized by the displacement D between the middle 205 of the X-ray detector 2 and the central ray 202 of the X-ray beam, can preferably be controlled by displacing the detector array relative to X-ray source 1 until the desired detector offset is achieved) (Fig. 2; [0039]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Sharma to include using the reconstruction technique for three-dimensional imaging since it increases the modality of the system, allows for the desired detector offset (Shafer; [0039]), as well as allows for an accurate image reconstruction can be carried out and the image reconstruction can start during the scan, so that the reconstructed image is available quickly after completion of the scan (Schafer; [0017] and [0041]).
Regarding claim 16, Sharma teaches wherein the processing system is configured to execute an iterative reconstruction algorithm (weighted iterative reconstruction) (p. 4; Section 2.A.3. Method III) that includes applying a noise model-based weighting (applying a splicing technique to ensure smooth merging) (p. 4; Section 2.A.3. Method III) to differences between measured and forward-projected data (difference between measured and forward-projected data) (p. 4; Section 2.A.3. Method III), and subsequently incorporating the redundancy weighting before back-projection (performing redundancy weighting before back-projection) (p. 3; Fig. 2 and p. 4; Section 2.A.3. Method III), thereby improving noise handling and artifact reduction (intended use; projection correction) (p. 4; Section 2.A.3. Method III).
Regarding claim 17, Sharma teaches further comprising a controller configured to operate the rotation stage (wherein the sample is rotated on a stage during data acquisition) (p. 5; Fig. 3 and Section 2.B.2., 1st paragraph) and acquire projections over a full 360-degree rotation of the sample to ensure sufficient sampling of regions within the enlarged field of view (by offsetting the detector, and acquiring projections over 360°, the effective FOV is larger than the original FOV without detector offset) (p. 2; left column, 1st paragraph).
Regarding claim 18, Sharma teaches wherein the controller is configured to rotate the sample only once over the full 360-degree rotation, thereby eliminating a need for multiple separate scans (by offsetting the detector, and acquiring projections over 360°, the effective FOV is larger than the original FOV without detector offset) (p. 2; left column, 1st paragraph).
Allowable Subject Matter
Claims 5 and 14 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Prior art Shafer et al., US 2012/0014582 A1: teaches a method is provided to reconstruct projection data obtained from CT imaging devices with offset detector geometries that includes the following steps: (i) matching projection data measured at opposing sides of the acquisition trajectory and splicing them together to generate a full, non-truncated projection data set; (ii) differentiation of the projection data; (iii) filtering the differentiated projection data with a filter, such as for example a Hilbert filter; (iv) applying redundancy weighting to the filtered projection data; and (v) back-projecting the redundancy weighted projection data to generate image data (Abstract).
Contact
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/MICHAEL J VANCHY JR/Primary Examiner, Art Unit 2666 Michael.Vanchy@uspto.gov
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