53 results about "X-Ray Phase-Contrast Imaging" patented technology

In a method to determine phase and/or amplitude between interfering, adjacent x-ray beams in a detector pixel in a Talbot interferometer for projective and tomographical x-ray phase contrast imaging and/or x-ray dark field imaging, after an irradiation of the examination subject with at least two coherent or quasi-coherent x-rays, an interference of the at least two coherent or quasi-coherent x-rays with the aid of an irradiated phase grating is generated, and the variation of multiple intensity measurements in temporal succession after an analysis grating is determined in relation to known displacements of one of the gratings or of an x-ray source fashioned like a grating, positioned upstream in the beam path, relative to one of the gratings. The integrating intensity measurements ensue during a relative movement—thus not during the standstill—of one of the upstream gratings or of the x-ray source fashioned like a grating or of the examination subject, with known speed behavior over a final time interval of a final distance.

A modified phase shifting mask is used to improve performance over traditional Zernike phase contrast imaging. The configurations can lead to an improved imaging methodology potentially with reduced artifacts and more than one order of magnitude gain in photon efficiency, in some examples. Moreover, it can be used to yield a direct representation of the sample's phase contrast information without the need for additional specialized post-acquisition image analysis. The approach can be applied to both wide-field and scanning configurations by using a phase mask including a pattern of phase elements and an illumination mask, having a pattern of holes, for example, that corresponds to a pattern of the phase mask.

Phase sensitive X-ray imaging methods can provide substantially increased contrast over conventional absorption based imaging, and therefore new and otherwise inaccessible information. The use of gratings as optical elements in hard X-ray phase imaging overcomes some of the problems that have impaired the wider use of phase contrast in X-ray radiography and tomography. So far, to separate the phase information from other contributions detected with a grating interferometer, a phase-stepping approach has been considered, which implies the acquisition of multiple radiographic projections. Here,an innovative, highly sensitive X-ray tomographic phase contrast imaging approach is presented based on grating interferometry, which extracts the phase contrast signal without the need of phase stepping. Compared to the existing phase step approach, the main advantage of this new method dubbed 'reverse projection' is the significantly reduced delivered dose, without degradation of the image quality. The new technique sets the pre-requisites for future fast and low dose phase contrast imaging methods, fundamental for imaging biological specimens and in-vivo studies.

The invention discloses a dual-energy X-ray phase-contrast imaging device and an implementation method thereof. The dual-energy X-ray phase-contrast imaging device comprises an X-ray apparatus, a source grating, a beam splitting grating, a sample chamber, an analysis grating and an X-ray detector along an optical path sequentially, wherein the X-ray apparatus is used for sending out X-rays; the source grating is used for dividing a large-focus X-ray source into a plurality of independent small-focus optical sources; the beam splitting grating is used for dividing the small-focus optical sources into a plurality of beams which irradiate a sample in the sample chamber, and a geometric projection is formed on the analysis grating; the sample chamber is used for holding and fixing the sample, and driving the sample to rotate at the same time; the analysis grating is used in cooperation with the beam splitting grating for forming moire fringes on the X-ray detector; the X-ray detector is used for obtaining and recording the moire fringes. When the dual-energy X-ray phase-contrast imaging device is utilized for dual-energy X-ray phase-contrast imaging, two selected energy values, namely V (high energy) and V (low energy) can be freely adjusted based on the actual situation, so that the usable range of dual-energy X-ray phase-contrast imaging can be widened.

The invention relates to an X ray phase contrast imaging system and an X ray phase contrast imaging method. The system comprises an X ray device, a grating system, a detection unit, a data processing unit and a relative shifting device, wherein the X ray device emits X ray bundles to a detected object; the grating system comprises a first absorption grating and a second absorption grating and is positioned on a direction of an X ray, and the X ray refracted by the detected object forms a variable-intensity X ray signal through the first absorption grating and the second absorption grating; the detection unit receives the variable-intensity X ray signal and converts the variable-intensity X ray signal into an electrical signal; the data processing unit processes and extracts the refraction angle information in the electrical signal and computes pixel information by utilizing the refraction angle information; and the relative shifting device is used for enabling the detected object to relatively shift relative to the imaging system. The imaging system carries out phase contrast imaging for the detected object within a certain relative shifting range of the imaging system and the detected object at a plurality of positions so as to obtain a plurality of images of the detected object. The images are converted into the images on the same reconstruction plane so as to carry out three-dimensional image reconstruction.

New methods for phase contrast imaging in transmission electron microscopy use the imaging electron beam itself to prepare a hole-free thin film for use as an effective phase plate, in some cases eliminating the need for ex-situ fabrication of a hole and reducing requirements for the precision of the ZPP hardware. The electron optical properties of the ZPP hardware are modified primarily in two ways: by boring a hole using the electron beam; and/or by modifying the electro-optical properties by charging induced by the primary beam. Furthermore a method where the sample is focused by a lens downstream from the ZPP hardware is disclosed. A method for transferring a back focal plane of the objective lens to a selected area aperture plane and any plane conjugated with the back focal plane of the objective lens is also provided.

Systems and methods for X-ray phase-contrast imaging (PCI) are provided. A quasi-periodic phase grating can be positioned between an object being imaged and a detector. An analyzer grating can be disposed between the phase grating and the detector. Second-order approximation models for X-ray phase retrieval using paraxial Fresnel-Kirchhoff diffraction theory are also provided. An iterative method can be used to reconstruct a phase-contrast image or a dark-field image.

A device and method of the present disclosure provides large field-of-view Talbot-Lau phase contrast CT systems up to very high X-ray energy. The device includes microperiodic gratings tilted at glancing incidence and tiled on a single substrate to provide the large field-of-view phase contrast CT system. The present disclosure is a simple, economical, and accurate method for combining multiple GAIs into a larger FOV system, capable of performing phase-contrast tomography (PC-CT) on large objects. The device and method can be applied to medical X-ray imaging, industrial non-destructive testing, and security screening.

A method of imaging an object that includes subjecting an object to a beam of radiation that is directed along a first direction and analyzing a first portion of the beam of radiation that is transmitted through the object along the first direction so that the intensity of the first portion is suppressed. Analyzing a second portion of the beam of radiation that is refracted from the object. Generating an image of the object based on the suppressed first portion of the beam of radiation and the second portion of the beam of radiation.

The invention discloses a digital image correlation (DIC) technical experimental device based on X-ray transmission imaging. The experimental device includes an X-ray light source, a scintillator, a reflector, a CCD camera and a computer. The X-ray generated by the X-ray light source passes through a test sample and carries the internal information of the test sample to the scintillator, the scintillator transforms the X-ray into visible light and transmits the light to the CCD camera, the CCD camera is connected to the computer, a phase contrast image of the test sample can be acquired through image acquisition software in the computer, and the computer processes the phase contrast image by DIC analysis method to acquire the displacement field and strain field of the test sample. The experimental device provided by the invention applies X-ray imaging technology to the traditional DIC experimental method, can represent the mechanical behavior of the material during loading to acquire full-field displacement and strain distribution, can achieve higher imaging quality, and is suitable for representation of microscale material deformation. In addition, with the help of X-ray penetration power, the XPCI (X-ray phase contrast imaging) image can also provide some additional material internal deformation information.

The invention relates to a method and a device for generating phase contrast X-ray images of an object (1). The device comprises an X-ray source (10) that may for example be realized by a spatially extended emitter (11) behind a grating (G₀). A diffractive optical element (DOE), for example a phase grating (G1), generates an interference pattern (I) from the X-radiation that has passed the object (1), and a spectrally resolving X-ray detector (30) is used to measure this interference pattern behind the DOE. Using the information obtained for different wavelengths/energies of X-radiation, the phase shift induced by the object can be reconstructed.

The invention is a ultra-fast pulse X ray phase contrast imaging device, it includes a femtosecond laser system, splitter, optical delaying line, all-mirror and target chamber, in which there arranges a achromatic lens, sample chamber, fixed target and concave reflecting mirror, there has a detector out of the target chamber. The position relation of above mentioned elements is: a splitter is arranged on the output light path of femtosecond titanium stone laser system, the splitter divides the laser bema into A, and B, the A beam enters the target chamber through optical delay, and it is gathered to radiate the gas in the sample chamber with achromatic lends, the B enters the target chamber through all-mirror, reflected by the reflecting mirror and gathered onto the target, generates a X ray, the X ray enters the sample chamber, the state of the plasma in the sample chamber is recorded by the detector, the distance between the detector and the gas chamber agrees the imaging condition.

The present application relates to the field of medical imaging, and discloses an X-ray grating phase contrast imaging reconstruction method and a system thereof. The method includes the following steps: obtaining downsampled projection data, extracting phase contrast projection, absorption projection and scattering projection; utilizing at least two projection data to reconstruct an image. This method makes full use of the material information obtained from grating phase contrast imaging and reconstructs images with two or three kinds of information. Compared with the existing technology, this method can obtain high-quality reconstructed images when the projection data of phase contrast CT imaging system is incomplete, thus realizing low-dose and fast grating phase contrast CT imaging.

A system and related method for X-ray phase contrast imaging. A signal model is fitted to interferometric measurment data. The fitting operation yields a Compton cross section and a photo-electric image. A pro-portionality between the Compton cross section and electron-density is used to achieve a reduction of the number of fitting variables. The Compton image may be taken, up to a constant, as a phase contrast images.

A device for slot scanning phase contrast x-ray imaging, includes an x-ray emitter, a plurality of x-ray gratings, a patient couch, and an x-ray detector. Position marker elements are arranged and configured in the beam path of the x-ray emitter such that the position marker elements are visible in an x-ray image. In the x-ray image, a relative position of an object on the patient couch in relation to an x-ray beam fan of the x-ray emitter may be established from a location and a distance of the position marker elements from one another.