124 results about "Differential phase contrast" patented technology

The invention relates to the field of X-ray differential phase contrast imaging. For scanning large objects and for an improved contrast to noise ratio, an X-ray device (10) for imaging an object (18) is provided. The X-ray device (10) comprises an X-ray emitter arrangement (12) and an X-ray detector arrangement (14), wherein the X-ray emitter arrangement (14) is adapted to emit an X-ray beam (16) through the object (18) onto the X-ray detector arrangement (14). The X-ray beam (16) is at least partial spatial coherent and fan-shaped. The X-ray detector arrangement (14) comprises a phase grating (50) and an absorber grating (52). The X-ray detector arrangement (14) comprises an area detector (54) for detecting X-rays, wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object (18). The object (18) has a region of interest (32) which is larger than a detection area of the X-ray detector (18) and the X-ray device (10) is adapted to generate image data of the region of interest (32) by moving the object (18) and the X-ray detector arrangement (14) relative to each other.

A device for imaging an object, such as for breast imaging, includes a gantry frame having mounted thereon an x-ray source, a source grating, a holder or other place for the object to be imaged, a phase grating, an analyzer grating, and an x-ray detector. The device images objects by differential-phase-contrast cone-beam computed tomography. A hybrid system includes sources and detectors for both conventional and differential-phase-contrast computed tomography.

A differential phase-contrast X-ray imaging system is provided. Along the direction of X-ray propagation, the basic components are X-ray tube, filter, object platform, X-ray phase grating, and X-ray detector. The system provides: 1) X-ray beam from parallel-arranged source array with good coherence, high energy, and wider angles of divergence with 30-50 degree. 2) The novel X-ray detector adopted in present invention plays dual roles of conventional analyzer grating and conventional detector. The basic structure of the detector includes a set of parallel-arranged linear array X-ray scintillator screens, optical coupling system, an area array detector or parallel-arranged linear array X-ray photoconductive detector. In this case, relative parameters for scintillator screens or photoconductive detector correspond to phase grating and parallel-arranged line source array, which can provide the coherent X-rays with high energy.

The present invention generally refers to a correction method for grating-based X-ray differential phase contrast imaging (DPCI) as well as to an apparatus which can advantageously be applied in X-ray radiography and tomography for hard X-ray DPCI of a sample object or an anatomical region of interest to be scanned. More precisely, the proposed invention provides a suitable approach that helps to enhance the image quality of an acquired X-ray image which is affected by phase wrapping, e.g. in the resulting Moiré interference pattern of an emitted X-ray beam in the detector plane of a Talbot-Lau type interferometer after diffracting said X-ray beam at a phase-shifting beam splitter grating. This problem, which is further aggravated by noise in the obtained DPCI images, occurs if the phase between two adjacent pixels in the detected X-ray image varies by more than π radians and is effected by a line integration over the object's local phase gradient, which induces a phase offset error of π radians that leads to prominent line artifacts parallel to the direction of said line integration.

The present invention generally refers to a correction method for grating-based X-ray differential phase contrast imaging (DPCI) as well as to an apparatus which can advantageously be applied in X-ray radiography and tomography for hard X-ray DPCI of a sample object or an anatomical region of interest to be scanned. More precisely, the proposed invention provides a suitable approach that helps to enhance the image quality of an acquired X-ray image which is affected by phase wrapping, e.g. in the resulting Moiré interference pattern of an emitted X-ray beam in the detector plane of a Talbot-Lau type interferometer after diffracting said X-ray beam at a phase-shifting beam splitter grating. This problem, which is further aggravated by noise in the obtained DPCI images, occurs if the phase between two adjacent pixels in the detected X-ray image varies by more than π radians and is effected by a line integration over the object's local phase gradient, which induces a phase offset error of π radians that leads to prominent line artifacts parallel to the direction of said line integration.

A differential phase-contrast X-ray imaging system is provided. Along the direction of X-ray propagation, the basic components are X-ray tube, filter, object platform, X-ray phase grating, and X-ray detector. The system provides: 1) X-ray beam from parallel-arranged source array with good coherence, high energy, and wider angles of divergence with 30-50 degree. 2) The novel X-ray detector adopted in present invention plays dual roles of conventional analyzer grating and conventional detector. The basic structure of the detector includes a set of parallel-arranged linear array X-ray scintillator screens, optical coupling system, an area array detector or parallel-arranged linear array X-ray photoconductive detector. In this case, relative parameters for scintillator screens or photoconductive detector correspond to phase grating and parallel-arranged line source array, which can provide the coherent X-rays with high energy.

A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in an optical path of the X-ray illumination system, and a detection system arranged in an optical path to detect X-rays after passing through the beam splitter.

Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital radiographic imaging system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a collimator and a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector, where a single arrangement of the beam shaping assembly, the x-ray grating interferometer and a position of the detector is configured to provide spectral information (e.g. at least two images obtained at different relative beam energies).

Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital radiographic imaging system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a collimator and a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector, where a single arrangement of the beam shaping assembly, the x-ray grating interferometer and a position of the detector is configured to provide spectral information (e.g. at least two images obtained at different relative beam energies).

Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital mammography system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a filter or a tunable monochromator, a collimator, a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector; where the source grating, the phase grating, and the analyzer grating are aligned in such a way that the grating bars of these gratings are parallel to each other.

A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in an optical path of the X-ray illumination system, and a detection system arranged in an optical path to detect X-rays after passing through the beam splitter.

A phase retrieval method for differential phase contrast imaging includes receiving data corresponding to a differential phase image generated from a measured signal. The measured signal corresponds to an X-ray signal detected by a detector after passing through a subject located with a grating arrangement between an X-ray source and the detector. The method further includes generating a phase image corresponding to the integration of the differential phase image. Generating the phase image includes performing an iterative total variation regularized integration in the Fourier domain.

An X-ray radiography system for differential phase contrast imaging of an object under investigation by phase-stepping is provided. The X-ray radiography has an X-ray emitter for generating a beam path of quasi-coherent X-ray radiation, an X-ray image detector with pixels arranged in a matrix, and a diffraction or phase grating, in which the X-ray emitter has an X-ray tube with a cathode and an anode. The X-ray tube is constructed in such a way that an electron ray beam originating from the cathode is associated with focusing electronics which produce, from electrons which are incident on an anode, at least one linear-shaped electron fan beam.

For correcting differential phase image data 52, differential phase image data 52 acquired with radiation at different energy levels is received, wherein the differential phase image data 52 comprises pixels 60, each pixel 60 having a phase gradient value 62a, 62b, 62c for each energy level. After that an energy dependent behavior of phase gradient values 62a, 62b, 62c of a pixel 60 is determined and a corrected phase gradient value 68 for the pixel 60 is determined from the phase gradient values 62a, 62b, 62c of the pixel 60 and a model for the energy dependence of the phase gradient values 62a, 62b, 62c.

Embodiments of methods and apparatus are disclosed for obtaining differential phase contrast imaging system and methods for same. Method and apparatus embodiments can provide regularized phase contrast retrieval that can address noise reduction and / or edge enhancement. Certain exemplary embodiments can suppress stripe artifacts occurring in the process of integration of noisy differential phase data. Further, certain exemplary embodiments can use transmission images and / or dark-field images to improve or restore phase contrast images affected by noise edges.

A device for imaging an object, such as for breast imaging, includes a gantry frame having mounted thereon an x-ray source, a source grating, a holder or other place for the object to be imaged, a phase grating, an analyzer grating, and an x-ray detector. The device images objects by differential-phase-contrast cone-beam computed tomography. A hybrid system includes sources and detectors for both conventional and differential-phase-contrast computed tomography.

A raw DPC (differential phase contrast) image of an object is acquired. The background phase distribution due to the non-uniformity of the grating system is acquired by the same process without an object in place, and the true DPC image of the object is acquired by subtracting the background phase distribution from the raw DPC image.

Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital radiographic imaging system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a collimator and a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector, where the phase-contrast digital radiographic imaging system and methods are adjustable for different mean energies of the x-ray source.

A raw DPC (differential phase contrast) image of an object is acquired. The background phase distribution due to the non-uniformity of the grating system is acquired by the same process without an object in place, and the true DPC image of the object is acquired by subtracting the background phase distribution from the raw DPC image.

The invention discloses a method and system based on a differential phase contrast imaging reduction quantitative phase image, and relates to the field of the computer imaging. The stable method from a target image to a reduction quantitative phase image is established. The method is capable of firstly establishing a differential phase contrast imaging two-dimensional optical phase transfer function H(u), and establishing the relation between the H(u), a frequency domain function of a differential phase contrast image (the figure is as shown in the specification) and the quantitative phase information, finally executing the deconvolution operation to recover the quantitative phase information through the phase transfer function of the differential phase contrast imaging. The method is capable of further researching a method of quantitatively recovering the phase information under the asymmetrical illumination pattern formed by multi-axis division so as to enhance the reconstitution capacity of the phase information in the different directions, and using the mathematical optimization to reduce the frequency noise increase caused by the direct deconvolution. The method is capable of overcoming the defects that the traditional quantitative image acquisition operation is complicated and the imaging condition is rigorous, and the obtained image resolution is higher.

A method for assembling a phase contrast x-ray imaging system includes fabricating a phase grating and an absorption grating according to a preselected pitch of the gratings. The actual obtained pitches are measured and a source grating is then fabricated according to a desired design point of the imaging system.

The invention relates to an X-ray differential phase-contrast imaging system which has three circular gratings. The circular gratings are aligned with the optical axis of the radiation beam and a phase stepping is performed along the optical axis with the focal spot, the phase grating and / or the absorber grating. The signal measured is the phase-gradient in radial direction away from the optical axis.

The present invention discloses a dual-channel structure optical digital phase contrast microscopy imaging system and a realization method thereof, wherein the system comprises a light source, a beam expansion collimating unit, a light splitter, a lens group and two same cameras. The beam expansion collimating unit is used to adjust the divergent light emitted out by the light source into the parallel light and irradiate to a to-be-detected object, the light splitter, the lens group and the two cameras form two sets of symmetrical 4f imaging systems and obtain two synchronization images to calculate a real-time bright field micrograph, a differential phase contrast graph and a quantitative phase diagram image. Based on utilizing the common and cheap devices in the market specifically, and by processing simply, a same phase contrast imaging effect can be realized, and the problems that the devices are expensive, and a spatial light modulator is sensitive to the polarization of the light, are solved.

The present invention relates to differential phase-contrast imaging, in particular to a structure of a diffraction grating, e.g. an analyzer grating and a phase grating, for X-ray differential phase-contrast imaging. In order to make better use of the X-ray radiation passing the object, a diffraction grating (14) for X-ray differential phase-contrast imaging is provided with at least one portion (24) of a first sub-area (26) and at least one portion (28) of a second sub-area (30). The first sub-area comprises a grating structure (54) with a plurality of bars (34) and gaps (36) being arranged periodically with a first grating pitch P G (38), wherein the bars are arranged such that thy change the phase and / or amplitude of an X-ray radiation and wherein the gaps are X-ray transparent. The second sub-area is X-ray transparent and wherein the at least one portion of the second sub-area provides an X-ray transparent aperture (40) in the grating. Portions of the first and second sub-areas are arranged in an alternating manner in at least one direction (42).

The invention relates to the technical field of nanometer resolution X ray wave zone plate microscopic imaging and specifically discloses an X ray differential phase contrast microscopic imaging system and an imaging method. The system sequentially comprises an X ray light source, a collecting lens, a sample stage, an X ray wave zone plate, an absorbing ring and an imaging detector along the X ray propagation direction. The X ray differential phase contrast microscopic imaging system is provided to overcome the defects of an X ray microscope taking a wave zone plate as an objective lens, and the X ray differential phase contrast microscopic imaging system and the two-dimensional and / or three-dimensional imaging method provided by the invention can be used for quickly imaging objects.

The present invention relates to differential phase-contrast imaging of an object (108). When reconstructing image information from differential phase-contrast image data, streak- like artefacts (502) may occur. The artefacts (502) may substantially reduce legibility of reconstructed image data. Accordingly, it may be beneficial for removing or at least suppressing said artefacts (502). Thus, a method (400) for regularized phase retrieval in phase-contrast imaging is provided comprising receiving (402) differential phase-contrast image data of an object (108); generating (404) reconstructed image data of an object (108) and presenting (406) reconstructed image data of the object (108). The differential phase-contrast image and the reconstructed image data comprise a two-dimensional data structure having a first dimension and a second dimension. Generating reconstructed image data comprises integration of image data in one of the first dimension and the second dimension of the data structure. A gradient operator is determined in the other one of the first dimension and second dimension of the data structure and the data structure is employed for reconstructing image data resulting in a reduction of artefacts (500) within the reconstructed image data.

The invention discloses a transverse dislocated absorption grating-based X ray grating differential phase contrast imaging method and device. The method comprises the following steps: arranging a Talbot-Lau imaging structure by the novel transverse dislocated absorption grating disclosed by the invention; acquiring the two-dimensional intensity image after X ray penetrates through an object by the imaging structure; and separating the X ray absorption contrast image, differential phase contrast image and scattering contrast image from the acquired two-dimensional intensity image by the Fourier analysis method. Compared with the traditional method, the embodiment of the invention does not need to move the grating, three types of contrast images can be obtained by single exposure, so the imaging time is greatly shortened, the imaging dose is reduced and the imaging efficiency and stability of a system are improved.