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 .
Response to Amendment
The amendment filed 04/27/2026 was entered. Claims 1-14 are all the claims pending in the application. Claims 1-14 were previously rejected. Claims 1, 11 and 12 are independent. By this instant Amendment, Applicant amended claims 1, 11 and 12 and canceling claims 5, 6 and 7. No new matter is added.
Response to Arguments
Applicant's arguments filed April 27, 2026 have been fully considered but are not persuasive for the reasons below.
Applicant’s arguments with respect to independent claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument, see below rejection.
Claim Rejections - 35 USC § 103
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.
Claim(s) 1 – 4 and 10 - 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Salomon et al. (“A Self-Normalization Reconstruction Technique for PET Scans Using the Positron Emission Data,” IEEE Transactions on Medical Imaging, Vol. 31, No. 12, pp. 2234-2240, 2012) in view of Bazrafkan (US Pub. No. 2017/0032170 A1).
With regards to claims 1, 11 and 12, Salomon teaches a PET detector normalization method, PET-scanning device and computer-implemented reconstruction/calibration technique for estimating the relative sensitivity of individual detector pixels or crystals using emission data acquired during a PET scan (Abstract; pp. 2234-2236; Figures 1 and 4).
Salomon specifically teaches using singles emission data from the PET scan, including photons measured before coincidence processing, and obtaining an accumulated singles value for each detector crystal. The detector-element singles values are arranged according to detector position and are used to estimate the relative sensitivity of the detector pixels or crystals (Abstract; pp. 2234-2237; Figure 4)
Salomon further teaches comparing the measured detector-element singles distribution with an expected spatial distribution in which slowly varying components correspond principally to the activity distribution and scanner geometry, while localized deviations correspond to detector-pixel sensitivity variation (pp. 2235-2237; Figure 4). Salomon uses the resulting relative sensitivities as normalization or correction factors during PET reconstruction (pp. 2237-2240).
Salomon therefore teaches acquiring singles emission data from a patient PET scan; generating a detector-element singles map or histogram in which each detector element is associated with its accumulated singles count; and using the detector-element data to determine relative detector element efficiencies. Salomon also teaches performing the method by a PET system processor and computer-implemented reconstruction/calibration software (pp. 2234-2240).
Salomon fails to expressly disclose applying a spatial high-pass filter to the generated histogram of singles emission data.
Bazrafkan teaches an image processing apparatus having a processor arranged to apply a spatial Gaussian high-pass filter to spatially organized image data. Bazrafkan explains that the high-pass filter removes the low-frequency component corresponding to an illumination gradient and tends to flatten the dynamic range before normalization (paragraphs [0040]-[0044]; Figures 3-5).
In view of the utility of suppressing a slowly varying spatial background while preserving localized detector-element response differences, it would have been obvious to a person of ordinary skill in the art before the effective filing date to modify Salomon to apply the spatial high-pass filtering taught by Bazrafkan to Salomon's detector-element singles histogram. Salomon already identifies the desired separation of localized detector sensitivity variation from a low-spatial-frequency background. Bazrafkan provides a known and predictable filtering technique for performing that separation.
With regards to claim 2, Salomon teaches using the calculated relative detector-pixel sensitivities as normalization or calibration corrections in the PET reconstruction process (Abstract; pp. 2237-2240).
With regards to claim 3, Salomon teaches relative sensitivity factors normalized to a common global scale for use as detector calibration factors (pp. 2236-2239). Bazrafkan additionally teaches normalizing spatially filtered data so that the component values are comparably weighted (paragraph [0043]). It would have been obvious to normalize the detector-element histogram to its total or average because such normalization provides the common scale required for relative detector efficiencies.
With regards to claim 4, Salomon teaches detector elements formed by individual PET detector crystals or pixels and accumulates singles for each such crystal (Abstract; pp. 2234-2237; Figure 4).
With regards to claim 10, Bazrafkan expressly teaches that the spatial high-pass filter is a Gaussian high-pass filter (paragraph [0042]; Figure 4).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Salomon et al. in view of Bazrafkan, as applied to claim 1 above, and further in view of Panin (US Pub. No. 2015/0297168 A1).
With regards to claim 8, Salomon modified by Bazrafkan teaches the method according to claim 1, but fails to expressly disclose that the PET-scanning detector has a non-circular inner surface.
Panin teaches PET detector arrangements that depart from a conventional complete detector ring. For example, Panin teaches an in-beam PET arrangement including opposed detector portions and an opening through which a patient may be positioned or irradiated, thereby providing a non-circular inner detection boundary (paragraph [0006]).
In view of the utility of calibrating the detector elements of known PET scanner geometries, it would have been obvious to a person of ordinary skill in the art before the effective filing date to use the detector-element efficiency method of Salomon and Bazrafkan in the non-circular PET arrangement taught by Panin. Detector sensitivity normalization is predictably required regardless of whether the detector inner surface is circular, polygonal, open or formed by opposed detector portions.
Claim(s) 9, 13 and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Salomon et al. in view of Bazrafkan, as applied to claim 1 above, and further in view of Chen et al. (US Pub. No. 2009/0074152 A1).
With regards to claims 9, 13 and 14, Salomon modified by Bazrafkan teaches the claimed method according to claim 1, but fails to expressly disclose an acquisition period of less than 60 seconds, less than 30 seconds, or less than 10 seconds.
Chen teaches treating medical-imaging acquisition time as a managed parameter and shortening acquisition time where the required data quality can be obtained, thereby improving efficiency and throughput (paragraphs [0061]-[0065]).
Where the general conditions of a claim are disclosed in the prior art, discovering an optimum or workable range by routine experimentation is not inventive. The claimed time periods are nested ranges of a known result-effective variable, and the record does not establish that the boundaries of 60 seconds, 30 seconds and 10 seconds produce a critical or unexpected result.
In view of the utility of reducing calibration time and increasing scanner throughput while retaining sufficient detector counts, it would have been obvious to a person of ordinary skill in the art before the effective filing date to shorten the Salomon acquisition to the minimum period providing adequate counting statistics, including periods below 60 seconds, 30 seconds and 10 seconds as permitted by the detector count rate and desired accuracy.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DJURA MALEVIC whose telephone number is (571)272-5975. The examiner can normally be reached M-F (9-5).
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/DJURA MALEVIC/Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884
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