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 § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 7, and 9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by the article “A framework for evaluating threshold variation compensation methods in photon counting spectral CT” by Persson, Mats, and Hans Bornefalk (hereafter Persson).
Regarding claim 1, Persson discloses a photon counting CT apparatus comprising processing circuitry configured to: perform first determination processing of determining spike components (pg. 1862 col. 2 “
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, which is the covariance matrix describing the variations in the measured number of counts between different dels” the variation being the spike component) in a counting image generated on the basis of sum data of photon detection results for a plurality of different X-ray energy bands (pg. 1861 col. 2 “Energy weighting means that the image presented to the human observer is a weighted sum of the images produced by the individual energy bins, with weight factors chosen to be optimal for distinguishing some particular feature”) and second determination processing of determining ring artifacts on the basis of a plurality of energy images generated on the basis of a photon detection result for each of the plurality of different X-ray energy bands (eq. 8; pg. 1863 B. q as a Metric of Ring Artifact Visibility); and remove or reduce ring artifacts in the counting image on the basis of both a result of the first determination processing and a result of the second determination processing (pg. 1863-1866 C. Inhomogeneity Comparison Methods describes three methods for reducing or removing ring artifacts).
Regarding claim 7, Persson discloses wherein the plurality of energy images are bin images reconstructed using photon detection results for each of the plurality of different X-ray energy bands (pg. 1861 col. 2 “Energy weighting means that the image presented to the human observer is a weighted sum of the images produced by the individual energy bins, with weight factors chosen to be optimal for distinguishing some particular feature”).
Regarding claim 9, Persson discloses a medical image processing method, using a computer, comprising: performing a first determination processing of determining spike components (pg. 1862 col. 2 “
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=
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v
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μ
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, which is the covariance matrix describing the variations in the measured number of counts between different dels” the variation being the spike component) in a counting image generated on the basis of sum data of photon detection results for a plurality of different X-ray energy bands (pg. 1861 col. 2 “Energy weighting means that the image presented to the human observer is a weighted sum of the images produced by the individual energy bins, with weight factors chosen to be optimal for distinguishing some particular feature”) and second determination processing of determining ring artifacts on the basis of a plurality of energy images generated on the basis of a photon detection result for each of the plurality of different X-ray energy bands (eq. 8; pg. 1863 B. q as a Metric of Ring Artifact Visibility); and removing or reducing ring artifacts in the counting image on the basis of both a result of the first determination processing and a result of the second determination processing (pg. 1863-1866 C. Inhomogeneity Comparison Methods describes three methods for reducing or removing ring artifacts).
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.
Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over the article “A framework for evaluating threshold variation compensation methods in photon counting spectral CT” by Persson, Mats, and Hans Bornefalk.
Regarding claim 2, Persson teaches the processing circuitry is further configured to: extract spike components from each of the plurality of energy images (pg. 1862 col. 2 “
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=
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o
v
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]
, which is the covariance matrix describing the variations in the measured number of counts between different dels” the variation being the spike component); and determine the ring artifacts on the basis of the spike components (eq. 8; pg. 1863 B. q as a Metric of Ring Artifact Visibility).
Persson fails to teach transform each of the plurality of energy images represented in orthogonal coordinates into polar coordinates. It would have been obvious to one of ordinary skill in the art at the time the invention was made to transform each of the plurality of energy images represented in orthogonal coordinates into polar coordinates since it was known in the art that transforming to polar coordinates can simplify the geometry of certain methods which increases efficiency and enhances quality.
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have transform each of the plurality of energy images represented in orthogonal coordinates into polar coordinates as known in the art in the processing circuitry of Persson for the purpose of increasing efficiency and enhancing quality.
Regarding claim 3, Persson teaches wherein, in the second determination processing (eq. 8), the processing circuitry is further configured to: calculate an index value (
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) regarding a first spike component on the basis of a result of comparison between the first spike component extracted at a first position of a first energy image among the plurality of energy images and pixel values at the first position in other energy images (pg. 1863 “This threshold can be found in… having homogeneous variance but different mean values for different projection lines. The benefit of connecting ring visibility with the statistical proper ties of the sinogram in this way is that one then obtains a visibility threshold that is not tied to any certain physical source of del-to-del inhomogeneity or any specific inhomogeneity compensation scheme.”); and determine whether the first spike component is caused by a ring artifact on the basis of a result of comparison between the index value and a threshold value (pg. 1863 col. 2 “The threshold for sinograms with inhomogeneous q therefore gives a criterion for when no rings are visible even in the worst case, i.e., if in the entire sinogram, there will be no visible rings”).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over the article “A framework for evaluating threshold variation compensation methods in photon counting spectral CT” by Persson, Mats, and Hans Bornefalk in view of the article "Removing ring artefacts for photon-counting detectors using neural networks in different domains" by Fang et al.
Regarding claim 6, Persson fails to teach wherein the processing circuitry is further configured to: determine, among the spike components determined in the first determination processing, a spike component whose position corresponds to a ring artifact determined in the second determination processing, as a ring artifact in the counting image; and remove or reduce ring artifacts in the counting image by subtracting the determined ring artifact in the counting image from the counting image.
Fang teaches determining, among the spike components determined in the first determination processing, a spike component whose position corresponds to a ring artifact determined in the second determination processing, as a ring artifact in the counting image; and removing or reducing ring artifacts in the counting image by subtracting the determined ring artifact in the counting image from the counting image (pg. 42451 col. 2 “This projection-domain U-net is the same with the projection domain network in Fig. 3. The estimated stripe artefacts are reconstructed using (8) to get corresponding estimated ring artefacts. The estimated ring artefacts from the first and second branches are respectively multiplied with factor 0.5 and then added to get the final estimated ring artefacts. The final estimated ring artefacts are subtracted from the corrupted image and then we can get the final artefacts-free image”) for the purpose of better ring artifact removal (pg.. 42451 col. 2 “The simulation results show that the comprehensive model performs better than the ring artefacts removal method that merely in image domain or projection domain”).
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have wherein the processing circuitry is further configured to: determine, among the spike components determined in the first determination processing, a spike component whose position corresponds to a ring artifact determined in the second determination processing, as a ring artifact in the counting image; and remove or reduce ring artifacts in the counting image by subtracting the determined ring artifact in the counting image from the counting image as taught by Fang in the processing circuitry of Persson for the purpose of better ring artifact removal.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over the article “A framework for evaluating threshold variation compensation methods in photon counting spectral CT” by Persson, Mats, and Hans Bornefalk in view of the article “Advanced virtual monoenergetic images: improving the contrast of dual-energy CT pulmonary angiography” by Meier et al.
Regarding claim 8, Persson teaches wherein the plurality of energy images are reconstructed using photon detection results for each of the plurality of different X-ray energy bands (pg. 1861 col. 2 “Energy weighting means that the image presented to the human observer is a weighted sum of the images produced by the individual energy bins, with weight factors chosen to be optimal for distinguishing some particular feature”).
Persson fails to teach wherein the plurality of energy images are virtual monochromatic X-ray energy images.
Meier teaches virtual monoenergetic (monochromatic) CT imaging improves contrast-to-noise ratio compared to standard CT imaging (pg. 1245 col. 1 “virtual monoenergetic extrapolations from dual-energy CT data have been introduced, which have the potential to improve the contrast-to-noise ratio (CNR) of contrast-enhanced structures as compared to a standard single-energy CT examination”).
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have wherein the plurality of energy images are virtual monochromatic X-ray energy images as taught by Meier in the processing circuitry of Persson for the purpose of improved contrast-to-noise ratio.
Allowable Subject Matter
Claims 4-5 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.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 4, the prior art of record does not disclose or suggest identify materials included in the plurality of energy images on the basis of the plurality of energy images; and determine the ring artifacts on the basis of results of comparison between theoretical pixel values, which are theoretical values calculated from mass attenuation coefficients of the identified materials, and measured pixel values, which are measured values calculated from the plurality of energy images, along with other claim limitations.
The article “A framework for evaluating threshold variation compensation methods in photon counting spectral CT” by Persson, Mats, and Hans Bornefalk; the article "Removing ring artefacts for photon-counting detectors using neural networks in different domains" by Fang et al.; and the article “Advanced virtual monoenergetic images: improving the contrast of dual-energy CT pulmonary angiography” by Meier et al., either singularly or in combination, does not disclose or suggest "identify materials included in the plurality of energy images on the basis of the plurality of energy images; and determine the ring artifacts on the basis of results of comparison between theoretical pixel values, which are theoretical values calculated from mass attenuation coefficients of the identified materials, and measured pixel values, which are measured values calculated from the plurality of energy images," along with other claim limitations.
Claim 5 is dependent on 4 so they are allowable for the same reason.
Contact Information
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/RICHARD O TOOHEY/Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884