# US 12,602,756 B2 · Method and system for analytical x-ray calibration, reconstruction and indexing using simulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,602,756 B2 - Document ID: US12602756B2 - Status: Granted - Kind: B2 - Application number: 18/048,178 - Filed: 2022-10-20 - Published: 2023-05-11 - Granted: 2026-04-14 - Earliest claimed: 2021-11-05 - Assignees: Carl Zeiss X-ray Microscopy, Inc. - Applicants: Carl Zeiss X-ray Microscopy, Inc. - Inventors: Matthew Andrew - Web page: https://patentgrep.com/patent/US12602756B2 ## CPC - G06T 7/00: Image analysis - G01N 23/046: using tomography, e.g. computed tomography [CT] - G01N 23/083: the radiation being X-rays - G01N 33/24: Earth materials (G01N33/42 takes precedence) - G06F 30/20: Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) - G01N 2223/04: and measuring absorption - G01N 2223/3306: object rotates - G01N 2223/419: computed tomograph - G01N 2223/616: earth materials - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A mineral characterization method for an x-ray CT system comprises generating one or more volume datasets of a sample and identifying phases in the sample by correcting the datasets based on simulations. This can be employed with a polychromatic x-ray simulation and a highly controlled and well scaled implementation of analytical reconstruction to index materials of known composition to reconstructed grayscale intensities. An example of an application of this technology is in the field of mineral characterization on geoscience samples, where a single sample may consist of many individual mineral phases, of unknown distribution. Also addressed is a workflow for data correction and calibration such that acquisition related uncertainties are minimized and reconstructed intensity robustness maximized. This is achieved when some material of known transmission is in the field of view for every projection to create a reference path. ## Claims ### Claim 1 A material characterization method for an x-ray CT system, comprising: generating one or more volume datasets of samples; and identifying phases in the samples by correcting the datasets based on simulations, wherein the simulations include assessing when materials of known composition, density, and thickness are present within a beam propagation path, and when they are not to determine a nominal transmission. ### Claim 2 (depends on 1) The method of claim 1, wherein the nominal transmission is converted into an effective reconstructed greyscale value by scaling to give an effective linear attenuation coefficient. ### Claim 3 (depends on 1) The method of claim 1, further including scaling by a beam hardening correction routine. ### Claim 4 (depends on 1) The method of claim 1, wherein the simulations include simulating the x-ray propagation through geometry of the sample. ### Claim 5 (depends on 4) The method of claim 4, wherein the simulations include simulating the response of the x-ray CT system. ### Claim 6 (depends on 1) The method of claim 1, further comprising correcting the projections before being used for generating the volume datasets. ### Claim 7 (depends on 6) The method of claim 6, further comprising correcting the projections as floating point data. ### Claim 8 (depends on 1) The method of claim 1, wherein a passthrough of only air path is in a field of view for projections and is used to generate the one or more volume datasets to create a reference path. ### Claim 9 An x-ray microscopy CT system, comprising: a source of generating x-rays; a sample holder for holding and rotating samples in the beam; a detector for detecting the beam after interaction with the samples; and a computer for receiving projections from the detector and generating one or more volume datasets of samples and identifying phases in the samples by correcting the datasets based on simulations, wherein the simulations assess when materials of known composition, density, and thickness are present within a beam propagation path, and when they are not to determine a nominal transmission. ### Claim 10 (depends on 9) The system of claim 9, wherein the nominal transmission is converted into an effective reconstructed greyscale value by scaling to give an effective linear attenuation coefficient. ### Claim 11 (depends on 9) The system of claim 9, wherein the computer further scales by a beam hardening correction routine. ### Claim 12 (depends on 9) The system of claim 9, wherein the computer simulates the x-ray propagation through geometry of the sample. ### Claim 13 (depends on 12) The system claim 12, wherein the simulations include simulating the response of the x-ray CT system. ### Claim 14 (depends on 9) The system of claim 9, wherein the computer corrects the projections before being used for generating the volume datasets. ### Claim 15 (depends on 14) The system of claim 14, wherein the computer correct the projections as floating point data. ### Claim 16 (depends on 1) The method of claim 1, wherein the simulations include comparing simulations of light intensities measured by a detector where the materials of known composition, density, and thickness are present within the beam propagation path, and where the materials of known composition, density, and thickness are not present within the beam propagation path, to determine the nominal transmission. ### Claim 17 (depends on 16) The method of claim 16, wherein a ratio of the light intensities measured by the detector corresponds to the nominal transmission. ### Claim 18 (depends on 17) The method of claim 17, wherein the nominal transmission is used for calibration in correcting the datasets.