# US 10,872,708 B2 · Phase contrast X-ray interferometry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,872,708 B2 - Document ID: US10872708B2 - Status: Granted - Kind: B2 - Application number: 16/044,111 - Filed: 2018-07-24 - Published: 2019-01-24 - Granted: 2020-12-22 - Earliest claimed: 2017-07-24 - Assignees: Board of Supervisors of Louisiana State University and Agricultural and Mechanical College - Applicants: Joyoni Dey; Narayan Bhusal; Leslie Butler; Jonathan P. Dowling; Kyungmin Ham; Varshni Singh - Inventors: Joyoni Dey; Narayan Bhusal; Leslie Butler; Jonathan P. Dowling; Kyungmin Ham; Varshni Singh - Web page: https://patentgrep.com/patent/US10872708B2 ## CPC - G21K 1/067: {using surface reflection, e.g. grazing incidence mirrors, gratings (multilayer mirrors G21K1/062)} - G01N 23/041: Phase-contrast imaging, e.g. using grating interferometers - G21K 1/06: using diffraction, refraction or reflection, e.g. monochromators (G21K1/10, G21K7/00 take precedence) - G21K 2207/005: Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES - 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) ## Abstract A phase contrast X-ray imaging system includes: an illumination source adapted to illuminate a region of interest; a diffraction grating adapted to receive illumination from the illuminated region of interest, the diffraction grating comprising a spatial structure having a first periodicity superimposed with a second periodicity that is different from the first periodicity; and a detector adapted to detect illumination passing through the diffraction grating, wherein the spatial structure is defined by varying height and/or pitch, and wherein the spatial structure imparts a first phase dependence based on the first periodicity and an additional phase dependence based on the second periodicity on the illumination passing through the diffraction grating. ## Claims ### Claim 1 A phase contrast X-ray imaging system comprising: an illumination source adapted to illuminate a region of interest; a diffraction grating adapted to receive illumination from the illuminated region of interest, the diffraction grating comprising a spatial structure having a first periodicity superimposed with a second periodicity that is different from the first periodicity; and a detector adapted to detect illumination passing through the diffraction grating, wherein the spatial structure is defined by varying height and/or pitch, and wherein the spatial structure imparts a first phase dependence based on the first periodicity and an additional phase dependence based on the second periodicity on the illumination passing through the diffraction grating. ### Claim 2 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the diffraction grating imparts a position-dependent quadratic phase, wherein the position-dependent quadratic phase is proportional to a square of a transverse distance from a pre-determined position on the diffraction grating in a first dimension. ### Claim 3 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the diffraction grating imparts a position-dependent quadratic phase, wherein the position-dependent quadratic phase is proportional to a square of a transverse distance from a pre-determined position on the diffraction grating in a first dimension and in a second dimension. ### Claim 4 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the grating imparts a position-dependent spherical phase. ### Claim 5 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the diffraction grating includes a plurality of grating elements, wherein the grating elements have a varying pitch that imparts the additional phase dependence on the illumination passing through the diffraction grating. ### Claim 6 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the diffraction grating contains a plurality of grating elements, wherein the grating elements have a varying pitch and a varying height, wherein the varying pitch and the varying height impart the additional phase dependence on the illumination passing through the diffraction grating. ### Claim 7 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the system does not include an absorption grating. ### Claim 8 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the illumination passes through a single grating before being detected by the detector. ### Claim 9 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the detector is curved. ### Claim 10 (depends on 1) The phase contrast X-ray imaging system according to claim 1, wherein the diffraction grating has a circular support, and wherein the phase contrast X-ray imaging system is used to perform single-shot dark-field imaging. ### Claim 11 (depends on 1) The phase contrast X-ray imaging system according to claim 1, further comprising a display device configured to display an image of the region of interest using the detected illumination. ### Claim 12 A grating for performing phase contrast X-ray imaging, comprising: a support structure; and a plurality of grating elements arranged to receive an X-ray beam therethrough, wherein the grating is adapted to change the phase of the X-ray beam in a quadratic or spherical-cap form, and wherein each of the plurality of grating elements has a transverse width of about 0.5 mm to about 2 mm, and wherein a height of the plurality of grating elements varies from a height corresponding to a 0 phase shift to a height corresponding to a it/2 phase shift of the X-ray beam. ### Claim 13 A grating for performing phase contrast X-ray imaging, comprising: a support structure; and a plurality of grating elements arranged to receive an X-ray beam therethrough, wherein the grating is adapted to change the phase of the X-ray beam in a quadratic or spherical-cap form, and wherein each of the plurality of grating elements has a transverse width of about 0.5 mm to about 2 mm, and wherein a height of the plurality of grating elements varies from a height corresponding to a 0 phase shift to a height corresponding to a π phase shift of the X-ray beam.