Patents by Inventor Xiaofeng NIU
Xiaofeng NIU has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9804275Abstract: A method and apparatus for generating crystal efficiency correction factors by performing a normalization calibration based on delayed data. The method and apparatus obtain delayed data from a scan of a patient using a Positron Emission Tomography (PET) scanner, generate a sinogram from the obtained delayed data, determine, using a processing circuit, mean fan and block line of response sensitivities from the generated sinogram, determine, using the processing circuit, mean detector efficiency based on the determined mean fan and block line of response sensitivities, determine, using the processing circuit, an individual crystal efficiency based on the determined mean fan and block line of response sensitivities and the mean detector efficiency for each module, and calculate the crystal efficiency correction factors based on the determined individual crystal efficiency of each module.Type: GrantFiled: November 19, 2013Date of Patent: October 31, 2017Assignee: Toshiba Medical Systems CorporationInventors: Xiaofeng Niu, Wenli Wang, Hongwei Ye
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Patent number: 9799126Abstract: An apparatus for performing a non-local means (NLM) filter is described. The pixel of the NLM-filtered image are weighted averages of pixels from a noisy image, where the weights are a measure of the similarity between patches of the noisy image. The similarity weights can be calculated using a Kullback-Leibler or a Euclidean distance measure. The similarity weights can be based on filtered patches of the noisy image. The similarity weights can be based on a similarity measure between patches of an anatomical image corresponding to the noisy image. The similarity weights can be calculated using a time series of noisy images to increase the statistical sample size of the patches. The similarity weights can be calculated using a weighted sum of channel similarity weights calculated between patches of noisy image that have been band-pass filtered. The NLM-filtered image can also be blended with a non-NLM-filtered image.Type: GrantFiled: October 2, 2015Date of Patent: October 24, 2017Assignee: Toshiba Medical Systems CorporationInventors: Wenyuan Qi, Xiaofeng Niu, Evren Asma, Wenli Wang, Ting Xia
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Publication number: 20170098317Abstract: An apparatus for performing a non-local means (NLM) filter is described. The pixel of the NLM-filtered image are weighted averages of pixels from a noisy image, where the weights are a measure of the similarity between patches of the noisy image. The similarity weights can be calculated using a Kullback-Leibler or a Euclidean distance measure. The similarity weights can be based on filtered patches of the noisy image. The similarity weights can be based on a similarity measure between patches of an anatomical image corresponding to the noisy image. The similarity weights can be calculated using a time series of noisy images to increase the statistical sample size of the patches. The similarity weights can be calculated using a weighted sum of channel similarity weights calculated between patches of noisy image that have been band-pass filtered. The NLM-filtered image can also be blended with a non-NLM-filtered image.Type: ApplicationFiled: October 2, 2015Publication date: April 6, 2017Applicant: TOSHIBA MEDICAL SYSTEMS CORPORATIONInventors: Wenyuan QI, Xiaofeng Niu, Evren Asma, Wenli Wang, Ting Xia
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Patent number: 9483850Abstract: A method and system for determining a position of a source including obtaining prompt data and related delayed data from a Positron Emission Tomography (PET) scanner, generating a sinogram from the prompt data, generating crystal efficiency correction factors by performing a normalization calibration based on the obtained delayed data, performing normalization correction on the generated sinogram based on the crystal efficiency correction factors to generate a corrected sinogram, rebinning the corrected sinogram to generate a plurality of two-dimensional sinogram slices, and determining a central axis for each of the plurality of two-dimensional sinogram slices using a center estimation process.Type: GrantFiled: November 19, 2013Date of Patent: November 1, 2016Assignee: TOSHIBA MEDICAL SYSTEMS CORPORATIONInventors: Xiaofeng Niu, Hongwei Ye, Wenli Wang
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Patent number: 9291725Abstract: A method and apparatus for reducing random events in positron emission tomography (PET) list mode data, the method including the steps of obtaining, for a PET scanner having a given reconstruction field of view (FOV), time-of-flight (TOF) prompt list-mode count data that includes TOF information, the TOF prompt list-mode count data including a plurality of entries; and filtering the obtained prompt list-mode count data by removing those entries in the obtained prompt list-mode count data that represent emission points lying outside a tangential TOF mask to obtain filtered list-mode count data.Type: GrantFiled: May 16, 2012Date of Patent: March 22, 2016Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems CorporationInventors: Wenli Wang, Xiaofeng Niu
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Patent number: 9286701Abstract: A method is provided for estimating scatter in a positron emission tomography (PET) scan at multiple bed positions, the method comprising calculating a first scatter sinogram based on scatter data obtained at a first bed position, calculating a second scatter sinogram based on scatter data obtained at a second bed position, and deriving a third scatter sinogram for a third bed position between the first bed position and the second bed position, wherein the third scatter sinogram is derived from the first scatter sinogram according to a first percentage of overlap of the first bed position with the third bed position, and from the second scatter sinogram according to a second percentage of overlap of the second bed position with the third bed position.Type: GrantFiled: August 28, 2014Date of Patent: March 15, 2016Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems CorporationInventors: Hongwei Ye, Xiaofeng Niu, Wenli Wang
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Publication number: 20160063741Abstract: A method is provided for estimating scatter in a positron emission tomography (PET) scan at multiple bed positions, the method comprising calculating a first scatter sinogram based on scatter data obtained at a first bed position, calculating a second scatter sinogram based on scatter data obtained at a second bed position, and deriving a third scatter sinogram for a third bed position between the first bed position and the second bed position, wherein the third scatter sinogram is derived from the first scatter sinogram according to a first percentage of overlap of the first bed position with the third bed position, and from the second scatter sinogram according to a second percentage of overlap of the second bed position with the third bed positionType: ApplicationFiled: August 28, 2014Publication date: March 3, 2016Applicants: Kabushiki Kaisha Toshiba, Toshiba Medical System CorporationInventors: Hongwei YE, Xiaofeng NIU, Wenli WANG
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Patent number: 9241678Abstract: A method of estimating random events in positron emission tomography list mode data, including obtaining time-of-flight (TOF) list mode count data that includes TOF information; converting the obtained TOF list mode count data into four-dimensional (4D) raw sinogram count data, without using the TOF information, wherein the 4D raw sinogram count data includes random count values; interpolating the 4D raw sinogram count data to generate 4D interpolated sinogram count data; low-pass filtering the 4D interpolated sinogram count data to remove noise; converting the low-pass filtered 4D interpolated sinogram count data into filtered 4D raw sinogram count data; and generating, by a processor, five-dimensional (5D) TOF raw sinogram count data from the filtered 4D raw sinogram count data by effectively applying a TOF mask filter to the filtered 4D raw sinogram count data.Type: GrantFiled: May 9, 2012Date of Patent: January 26, 2016Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems CorporationInventors: Xiaofeng Niu, Wenli Wang
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Publication number: 20150139513Abstract: A method and system for determining a position of a source including obtaining prompt data and related delayed data from a Positron Emission Tomography (PET) scanner, generating a sinogram from the prompt data, generating crystal efficiency correction factors by performing a normalization calibration based on the obtained delayed data, performing normalization correction on the generated sinogram based on the crystal efficiency correction factors to generate a corrected sinogram, rebinning the corrected sinogram to generate a plurality of two-dimensional sinogram slices, and determining a central axis for each of the plurality of two-dimensional sinogram slices using a center estimation process.Type: ApplicationFiled: November 19, 2013Publication date: May 21, 2015Applicants: Toshiba Medical Research Institute, KABUSHIKI KAISHA TOSHIBAInventors: Xiaofeng NIU, Hongwei Ye, Wenli Wang
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Publication number: 20150142389Abstract: A method and apparatus for generating crystal efficiency correction factors by performing a normalization calibration based on delayed data. The method and apparatus obtain delayed data from a scan of a patient using a Positron Emission Tomography (PET) scanner, generate a sinogram from the obtained delayed data, determine, using a processing circuit, mean fan and block line of response sensitivities from the generated sinogram, determine, using the processing circuit, mean detector efficiency based on the determined mean fan and block line of response sensitivities, determine, using the processing circuit, an individual crystal efficiency based on the determined mean fan and block line of response sensitivities and the mean detector efficiency for each module, and calculate the crystal efficiency correction factors based on the determined individual crystal efficiency of each module.Type: ApplicationFiled: November 19, 2013Publication date: May 21, 2015Applicants: TOSHIBA MEDICAL SYSTEMS CORPORATION, KABUSHIKI KAISHA TOSHIBAInventors: Xiaofeng NIU, Wenli Wang, Hongwei Ye
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Patent number: 8942452Abstract: A method and apparatus for smoothing random event data obtained from a Positron Emission Tomography (PET) scanner. The method includes obtaining initial random event data u(s, ?, t=0)=u0(s, ?), corresponding to t=0, calculating second-order central differences uss, u?? with respect to s, ?, calculating a gradient ut, using ut=2(uss+u??)??(u?u0), where ? is a constant parameter, and updating the random event data using u(s, ?, t2)=u(s, ?, t1)+?t ut, where ?t=t2?t1, t1=0 in a first iteration, and ?t is greater than 0. The method repeats the steps of calculating the second-order central differences, calculating the gradient, and updating the random event data until a change in u(s, ?, t) from a previous iteration is less than a predetermined threshold value.Type: GrantFiled: May 18, 2012Date of Patent: January 27, 2015Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems CorporationInventors: Xiaofeng Niu, Wenli Wang
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Patent number: 8809792Abstract: A method and apparatus for determining a coincidence window for imaging a region of interest of an object using a Positron Emission Tomography (PET) scanner. The method includes determining a diameter of a transverse field of view (FOV) for imaging the region of interest of the object; and calculating the coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.Type: GrantFiled: September 28, 2012Date of Patent: August 19, 2014Assignees: Kabushiki Kaisha Toshiba, Toshiba Medical Systems CorporationInventors: Wenli Wang, Daniel Gagnon, Xiaofeng Niu
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Publication number: 20140095106Abstract: A method and apparatus for determining a coincidence window for imaging a region of interest of an object using a Positron Emission Tomography (PET) scanner. The method includes determining a diameter of a transverse field of view (FOV) for imaging the region of interest of the object; and calculating the coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.Type: ApplicationFiled: September 28, 2012Publication date: April 3, 2014Inventors: Wenli WANG, Daniel Gagnon, Xiaofeng Niu
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Publication number: 20130311142Abstract: A method and apparatus for reducing random events in positron emission tomography (PET) list mode data, the method including the steps of obtaining, for a PET scanner having a given reconstruction field of view (FOV), time-of-flight (TOF) prompt list-mode count data that includes TOF information, the TOF prompt list-mode count data including a plurality of entries; and filtering the obtained prompt list-mode count data by removing those entries in the obtained prompt list-mode count data that represent emission points lying outside a tangential TOF mask to obtain filtered list-mode count data.Type: ApplicationFiled: May 16, 2012Publication date: November 21, 2013Applicants: Toshiba Medical Systems Corporation, Kabushiki Kaisha ToshibaInventors: Wenli WANG, Xiaofeng NIU
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Publication number: 20130308873Abstract: A method and apparatus for smoothing random event data obtained from a Positron Emission Tomography (PET) scanner. The method includes obtaining initial random event data u(s, ?, t=0)=u0(s, ?), corresponding to t=0, calculating second-order central differences uss, u?? with respect to s, ?, calculating a gradient ut, using ut=2(uss+u??)??(u?u0), where ? is a constant parameter, and updating the random event data using u(s, ?, t2)=u(s, ?, t1)+?t ut, where ?t=t2?t1, t1=0 in a first iteration, and ?t is greater than 0. The method repeats the steps of calculating the second-order central differences, calculating the gradient, and updating the random event data until a change in u(s, ?, t) from a previous iteration is less than a predetermined threshold value.Type: ApplicationFiled: May 18, 2012Publication date: November 21, 2013Applicants: Toshiba Medical Systems Corporation, Kabushiki Kaisha ToshibaInventors: Xiaofeng Niu, Wenli Wang
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Publication number: 20130304386Abstract: A method of estimating random events in positron emission tomography list mode data, including obtaining time-of-flight (TOF) list mode count data that includes TOF information; converting the obtained TOF list mode count data into four-dimensional (4D) raw sinogram count data, without using the TOF information, wherein the 4D raw sinogram count data includes random count values; interpolating the 4D raw sinogram count data to generate 4D interpolated sinogram count data; low-pass filtering the 4D interpolated sinogram count data to remove noise; converting the low-pass filtered 4D interpolated sinogram count data into filtered 4D raw sinogram count data; and generating, by a processor, five-dimensional (5D) TOF raw sinogram count data from the filtered 4D raw sinogram count data by effectively applying a TOF mask filter to the filtered 4D raw sinogram count data.Type: ApplicationFiled: May 9, 2012Publication date: November 14, 2013Applicants: Toshiba Medical Systems Corporation, Kabushiki Kaisha ToshibaInventors: Xiaofeng NIU, Wenli WANG