X-ray Tomography

Abstract

An x-ray tomography system can generate a qualitative 3D image of a target region using an x-ray source, the x-ray source being configured to emit x-ray radiation at the target region. The x-ray radiation or the x-ray source or the relative position of the x-ray source being configured to move in a two-dimensional plane. An x-ray detector comprising a plurality of detector elements arranged in a two-dimensional plane relative to the x-ray source, the x-ray detector being configured to detect the x-ray radiation after being attenuated by an object and to provide an indication of the detected x-rays. And a processor being configured to receive an indication of the detected x-rays and to interpret the detected x-ray radiation into a three-dimensional image. The three-dimensional image is qualitative in nature.

Description

[0001] Incorporation by reference into any priority application

[0002] Pursuant to 37 CFR 1.57, any and all applications filed with the present application that claim foreign or domestic priority identified in the Application Data Sheet are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to three-dimensional x-ray imaging for medical and industrial applications.

[0004] background

[0005] Three-dimensional (3D) x-ray images are usually generated using computed tomography (CT), which includes an x-ray source that generates a fan beam or a spot beam, and a linear or corresponding point detector or sometimes a small 2D detector in the shape of an arc. Cone beam CT (a variant of CT) usually includes a C-arm mounted CT unit and a digital flat panel detector, in which the object or source / detector rotates around an axis. Multiple images of the entire object need to be taken at large angles (usually greater than 180°) to reconstruct a 3D image of the object. This means that the object receives a relatively high dose of radiation. The process is also time-consuming. Current 3D CT systems are not suitable for portability, especially outside a hospital or surgical center or mobile diagnostic and surgical station.

[0006] Current non-rotational tomography is typically accomplished by using one or more 2D flat panel detectors combined with two or more x-ray sources in a linear array or arc array or in a 2D plane or in 3D space.

[0007] Techniques based on inverse geometry CT tomography require the use of a two-dimensional (2D) collimator with holes combined with a scanning x-ray source that emits through these holes before passing through the object.

[0008] Tomographic images obtained in non-rotational CT systems are not high resolution and do not provide the quantitative information typically provided by 3D CT scanners.

[0009] Scatter interferometry is a major problem in both rotational and non-rotational CT.

[0010] In rotational CT, the ratio of the scatter to primary X-ray ratio (SPR) is almost proportional to the rotation axis angle coverage of the X-ray cone beam. However, for lower rotation axis coverage, longer scanning times are required to acquire the images required for tomography.

[0011] Currently, a lot of effort is spent on the new concept of spectral CT, which uses the spectral information of the transmitted X-rays to extract additional information about the scanned patient or object. The SPR is high in spectral CT. For lower energies, the primary intensity is gradually covered by the scattered radiation. With the constraint that the scattered to primary ratio is recommended not to exceed a value of 1, it is recommended to use the energy of the measured single photons for spectral processing above a certain limit (e.g., between about 30-35keV).

[0012] In CT, as the scatter to primary ratio (SPR) increases, image artifacts appear and degrade image quality.

[0013] Anti-scatter grids (ASGs) are a key solution to reduce scatter in CT. Even with ASG correction, the SPR remains, for example, 20% or more for many energy levels.

[0014] For high-resolution imaging, the contrast-to-noise ratio CNR (an indicator for image quality) may not improve significantly, and the visibility of low-contrast details may be reduced using ASG.

[0015] Overview

[0016] Most current CT reconstruction theories assume that X-ray photons are absorbed or pass through the irradiated object without interaction, that is, when SPR is 0. In human body imaging, the ratio of scattering to primary signal is usually as high as 50% to 100%. The present disclosure provides a system capable of generating a complete 3D image of a target area from a two-dimensional scanning process. The generated image can have a thickness or depth or dimension (for example, in the z-axis plane) including three or more data points. Each data point can be resolved by x-ray measurement or optical measurement or other dimensional measurement methods. This can be achieved by minimizing the number of measurements using a 2D detector. This can be achieved by minimizing the introduction of unknown pixels outside the target area in 1D, 2D and 3D space. By minimizing the moving distance and moving size, by minimizing hardware and moving complexity, by minimizing x-ray acquisition time, by minimizing radiation exposure and / or by simplifying the 3D x-ray imaging method and equipment of the prior art, the introduction of minimized unknown factors can be achieved.

[0017] By using a compact system with few or no moving parts, the present disclosure provides a three-dimensional x-ray imaging system using a two-dimensional system. The system can also generate x-ray measurements for the target area of ​​an object with multiple components inside, which can be quantitatively analyzed, including material decomposition, identification and characterization of the physical and chemical properties of the components and determination of measurements, such as atomic weight, density, detailed size and microstructure and features in space, positioning of components in space, dynamic motion characteristics, fluid dynamics, time-stamp identification and positioning, flexibility of components, interactions between components (such as molecular and / or cellular interactions), identification of components based on one or more such characteristics. The system can provide all of the above benefits in one system. This type of system has a wide range of applications in hospitals, surgical centers and mobile stations. It also provides portability for such systems in a conventional portable form, carry-on, foldable manner, for field applications, such as field sports medicine, veterinary medicine, remote and dynamic diagnosis and imaging guidance and material identification. The present disclosure can also provide ultrafast image construction of 3D images to enable real-time measurements and time-dependent measurements in multidimensional imaging.

[0018] The present disclosure may also enable more capabilities for quantitative imaging for other non-rotational tomography systems (e.g., reverse geometry scanning fluoroscopes, multi-dimensional systems with 2D detectors connected to motorized x-ray sources that can move in arcuate or linear directions, and / or static multiple x-ray sources), systems with x-ray sources that can be positioned or moved in 1D, 2D, or 3D dimensions, pixelated 2D flat panel x-ray sources, or x-ray sources consisting of cathodes, each having multiple individually programmable electron emitting units for emitting electron beams when an electric field is applied, an anode target that emits an x-ray beam when struck by an electron beam from the emitting x-ray source, and / or a metal liquid jet source.

[0019] The present disclosure improves imaging modalities such as x-ray microscopy and interferometry including Fourier transform methods, x-ray interferometry, coherent x-ray phase contrast x-ray imaging, coherence contrast x-ray imaging by providing a fast and non-rotating CT system and in some cases providing quantitative capabilities.

[0020] Compared with the present disclosure, in the prior art, the speed bottleneck for acquiring fast 3D images is usually the speed of the motion system, and the speed limiting factor is the frame rate of the detector.

[0021] Objects of the present disclosure will become apparent from the following drawings and detailed description of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] For a more complete understanding of the nature and objects of the present disclosure, reference is made to the accompanying drawings, in which:

[0024] Figure 1 is a schematic diagram of the basic hardware configuration used in the present disclosure;

[0025] Figure 2 It has a three-layer detector structure Figure 1 Schematic diagram of a hardware configuration in which a beam selector with a fixed focus blocks primary x-rays from selected locations of a rear detector;

[0026] Figure 3 It has a three-layer detector structure Figure 1 Schematic diagram of a hardware configuration in which a beam selector with a fixed focus blocks scattering from selected locations of a detector;

[0027] Figure 4 is a side view of a portion of a beam selector with an adjustable focus using a compressible material that blocks scatter from selected locations of a rear detector;

[0028] Figure 5 is a side view of a portion of a beam selector with an adjustable focus using x-ray absorbing beads that blocks scatter from selected locations of a rear detector;

[0029] Figure 6 It is adjusted to the focus Figure 4 a side view of a portion of a beam selector;

[0030] Figure 7 is a perspective view of a beam selector with a movable focus using rigid material and showing some of the tubes;

[0031] Figure 8 yes Figure 7 A top view of a beam selector;

[0032] Fig. 9 It is adjusted to a closer center focus. Figure 7 A side view of a beam selector;

[0033] Fig.10 It is adjusted to the center focus of the middle distance Figure 7 A side view of a beam selector;

[0034] Fig.11 It is adjusted to a farther center focus. Figure 7 A side view of a beam selector;

[0035] Fig.12 It is adjusted to the left edge focus of the middle distance Figure 7 A side view of a beam selector;

[0036] Fig.13 It is adjusted to the focus on the right edge of the middle distance Figure 7 A side view of a beam selector;

[0037] Fig.14 is a side view of a beam selector with a movable focus using stacked plates;

[0038] Fig.15 Adjust to different focal points Fig.14 A side view of a beam selector;

[0039] Fig.16 Unknown areas are shown;

[0040] Fig.17 An implementation scheme for resolving the unknowns on the z-axis is shown.

[0041] Fig.18 is a side view of a detector assembly having a scatter blocking beam selector and a rear detector unit only at the bottom of the well;

[0042] Fig.19 is a schematic diagram of an x-ray source that uses total internal reflection of a polycapillary tube to produce x-ray beams emitted from different positions;

[0043] Fig. 20 is a schematic diagram of an x-ray source using magnetic deflection;

[0044] Fig.21 is a schematic diagram of a system using crystal interferometry;

[0045] Fig. 22 is a schematic representation of a voxel as assumed in the present disclosure, where D x =D y ≠D z ;

[0046] Fig.23 A nanotube field emitter system is shown;

[0047] Fig.24A -C shows the configuration of the field emitter active area;

[0048] Fig.25 is a flow chart of the basic steps of the 3D imaging method;

[0049] Fig.26 is a flow chart of the basic steps of the 3D imaging method, with an added step to separate primary x-rays and scatter;

[0050] Fig. 27 is a flow chart of the basic steps of the 3D imaging method, to which steps for 2D and 3D functional imaging are added;

[0051] Fig.28is a flow chart showing multi-dimensional imaging from at least two 2D images taken at two different x-ray emission positions;

[0052] Fig.29 Schematic diagram of a steered electron beam in an x-ray tube with a programmable field emission unit.

[0053] Fig.30 A number of pixels along the projection path are shown.

[0054] Fig.31 The configuration for x-ray microscopy is shown.

[0055] Fig.32 is an example of an x-ray source.

[0056] Details

[0057] A general spectral imaging description is described in JT Dobbins, Handbook of Medical Imaging III, Image Quality Metrics for digital systems, 2000, pp. 161-219, the projection signal from a detector element at energy level Ω,

[0058] ∈{E1,E2,E3...}

[0059] D(Ω)=qΩ∫ΦΩ(E)exp[-μ1(E)t1-μ2(E)t2-μ3(E)t3…]×SΩ(E)dE, (1)

[0060] where q is the number of incident photons, Φ is the normalized incident energy spectrum, and S is the detector response function. The linear attenuation coefficients and integrated thicknesses of the various materials that make up the object are denoted μ and t, which attenuate the X-ray beam according to the Lambert–Beers law. If we define the attenuation of the object along the projection path in measurement units μ(E)t (where t = the time of the measurement unit), then when the measurement unit is the pixel pitch, μ(E)t is the attenuation from a pixel, named X. If there are p pixels along the projection path measured by the detector element, the equation can be rewritten as:

[0061] D(Ω)=qΩ∫ΦΩ(E)exp[-X1-X2-X 3 …-X z ]×SΩ(E)dE, (2)

[0062] For example, Fig.30 As shown in , z=12.

[0063] The basic approach is to solve a system of linear equations with m×n×p variables and m×n×p systems of equations. The current CT method assumes that the size of the pixel is Xa=Xb=Xc, and we will extend it to the case where Xc is not equal to Xc. The current method takes a value of 1 or 0 when watching the x-ray passing through the pixel, taking a value of 1 for the ray passing through the pixel and 0 otherwise. When passing through, the capacity is always the same. In the present disclosure, alignment is performed at each angle and x-ray emission position before acquisition. (I,j) Receiving signals through 1, 2, ...12, each sub-pixel transmission can be calculated. It is assumed that within each pixel, the transmission is uniform and proportional to the capacity.

[0064] The present disclosure includes methods and systems for producing three-dimensional (3D) images of an object using a two-dimensional (2D) x-ray detector by removing scatter, by calibration methods, and novel 3D reconstruction methods. The methods and systems may include performing a plurality of steps, some of which are optional, as described below: (1) calibration, (2) acquiring 2D images from at least two different x-ray source positions relative to the object, (3) processing the 2D images to separate primary x-rays from scatter, (4) performing functional processing on the 2D images, (5) processing to produce a 3D image from the 2D images, functional processing of the 3D images, and / or presentation of the acquired information.

[0065] exist Figure 1 Schematically shown in the preferred basic hardware used in the present disclosure. It includes an x-ray source 12 and a two-dimensional (2D) x-ray detector assembly 14. An image object 2 is located between the source 12 and the detector assembly 14. The detector assembly 14 communicates with a processor 15 including a memory 19. The processor communicates with user input and output 17, including, for example, a display screen, a keyboard and / or a mouse as will be understood by those skilled in the art. Other user interface elements may also be used as will be understood by those skilled in the art from this disclosure.

[0066] As described in step (2) above, a plurality of 2D images are acquired. For each image, the position 16 from which the x-rays 30 are emitted relative to the object 2 is moved in a plane 18 parallel to the plane of the detector assembly 14. Therefore, as described in detail below, the x-ray source 12 includes a mechanism for such movement. In the remainder of the present specification, the position from which the x-rays 30 are emitted is referred to as the emission position 16.

[0067] As described in step (3) above, primary x-rays and x-ray scatter are separated in the 2D image before the image is used. Typically, scatter is removed and discarded, which is why the separation is often referred to as scatter removal in the remainder of this application specification. However, in some cases, scatter is used alone, such as for transvascular imaging, material differentiation, and for identification and inspection of better visualization of low atomic z tissues.

[0068] Primary X-ray and scatter separation methods

[0069] refer to Figure 2 , when x-rays 30 from source 12 strike object 2, a portion of x-rays 30 pass directly through object 2 to detector assembly 14 without changing the direction of propagation. These are called primary x-rays 32 and convey true information about the attenuation characteristics of object 2. The remainder of x-rays 30 are randomly scattered as a result of interaction with the material of object 2. These are called scatter 34 and distort the true information. In some cases, this distortion is used to form a separate image, which can also be used to represent true information about the object.

[0070] In some cases, scatter may be ignored. For example, where the detector assembly 14 is a single 2D detector 20 that will receive both primary x-rays 32 and scatter 34, it may be assumed that scatter 34 is present, but the amount of scatter 34 is small enough that qualitatively correct but quantitatively inaccurate imaging results may still be obtained in some cases. The extent to which the amount of scatter 34 is acceptable depends on the circumstances and must be determined by analysis of the specific circumstances.

[0071] Primary x-rays and x-ray scatter can also be separated in the time domain using a fast x-ray source. This method exploits the property that primary x-rays 32 travel in a straight line from source 12 to detector assembly 14, taking minimal propagation time. Because scatter 34 does not travel in a straight line from source 12 to detector assembly 14, it takes longer to reach detector assembly 14. Thus, x-rays arrive at any given detector unit 28 continuously over a period of time, of which only the first x-ray is a primary x-ray. All others are scatter. Unfortunately, x-ray generation that allows for such analysis time is very expensive and impractical.

[0072] The apparatus and methods described in Chao's U.S. Patent Nos. US6052433A, US5648997A, US5771269A, US6173034B1, US6134297A can be used for scatter removal of any embodiment of the present disclosure, including instances where the x-ray source emission locations are close enough together that the use of beam selection tools is not substantially affected. The foregoing disclosures are incorporated herein by reference in their entirety.

[0073] In one example of the method, source 12 is capable of generating x-rays in extremely short pulses (e.g., on the order of picoseconds in duration), and detector assembly 14 is a 2D detector 20 capable of capturing images very quickly, on the order of picoseconds. The captured image includes at least primary x-rays 32 and scatter 34 that arrive at detector 20 during a capture time window. If the capture window is short enough, the amount of scatter 34 in the captured image is minimized. As the capture window becomes shorter, scatter 34 becomes a smaller component of the captured image.

[0074] Another approach is to separate the primary x-rays 32 and scattered x-rays 34 in the frequency domain. It exploits the properties of some materials where x-rays are spatially modulated by attenuation as they pass through the material. The x-rays 30 from the x-ray source 12 are modulated at a different (usually much higher) frequency than the scattered x-rays from the object 2. The x-rays, which are high frequency attenuation modulated x-rays of the primary x-rays, can be separated from the scattered x-rays by post image processing.

[0075] The present disclosure contemplates that any form of x-ray modulator may be used. One example is a high spatial frequency mode plate composed of attenuating barriers.

[0076] In another example, the modulator is a phase retarder diffraction grating beam splitter with a high spatial frequency pattern in order to separate the x-ray signal by primary x-rays and scattering in the space, frequency or time domain. In one form, such a modulator includes a crystal or x-ray optical device, such as a beam splitter, for example, a kinoform structure. In addition, such a material can be modulated or tunable by acoustic waves in at least one dimension. In another example, the modulator is a MEM device that acts as a high spatial frequency mode plate composed of an attenuation blocker, a phase modulator or a polar modulator. Depending on the application, such a modulator can function in a static or tunable state.

[0077] Another example is to generate an interferogram by applying modulation in space, time or frequency, or a combination of two or more domains, thereby separating primary x-rays and scatter based on differences in frequency or time or spatial location.

[0078] In another mechanism, a transmission beam combiner is used to combine x-ray beams from two or more x-ray sources. The interference fringes of the x-ray sources at the energy level or specific wavelength of the x-rays move as the phase difference between the x-ray beams of the x-ray sources changes relative to each other, or alternatively as the wavelength of the x-rays changes. The result is a modulated interferogram that produces a modulated spatial pattern that can be separated from the spatial pattern of the scattered x-rays.

[0079] Similarly, one or more gratings are used to generate two or more micro-sources of the x-ray source 12. The gratings can be dynamic or tunable gratings (such as those formed as MEMs), or they can be static (such as crystal gratings). The x-ray beams from the micro-sources interfere with each other and produce a moving interference fringe pattern when the gratings are tuned. The result is a modulated interference pattern that produces a modulated spatial pattern.

[0080] Similarly, a grating or beam splitter can be used to split at least one x-ray source 12 into two or more micro sources with variable phases. As the wavelength or energy of the x-rays changes, the interference pattern moves in space. When the scattered x-rays are separated from the signal resulting in the interferogram measurement, the scattered and primary x-rays are separated.

[0081] Another method of separating scattered and primary x-rays is described in detail in U.S. Pat. No. 6,134,297. Figure 2 As shown, the detector assembly 14 is a three-layer structure of a front 2D detector 22 closest to the source 12, a 2D beam selector 24, and a rear 2D detector 26. A combination of primary x-rays 32 and scatter 34 reaches and passes through the front detector 22. The beam selector 24 allows only the scatter 34 to pass through to a selected location 54 of the rear detector 26.

[0082] The beam selector 24 may be an array of cylinders 62 that include x-ray absorbing material and are supported by a thin plastic sheet 60 that has negligible x-ray absorption. The cylinders 62 are manufactured so that their axes are aligned with the direction of travel of the primary x-rays 32. As a result, the cylinders 62 block all x-rays directly from the x-ray source 12 within their cross-sectional area. Thus, each cylinder 62 produces a selected "shadow" location 54 on the rear x-ray detector 26 where the intensity of the primary x-rays 32 is substantially zero, while the intensity of the scatter 34 is substantially unaffected.

[0083] Because the cylinder 62 has a finite size, a small portion of the scatter 34 will not reach the shadow location 54. However, as long as the cylinder 62 is small, the scatter 34 can be controlled to be negligibly small. If the cylinder 62 is too large or too many, too much of the scatter 34 will be prevented from reaching the rear detector 26. The more cylinders 62 there are in the beam selector 24, the higher the measurement accuracy at the rear detector 26.

[0084] The cylinders 62 are manufactured so that their axes are aligned with the direction of travel of the primary x-rays 32 , which means that the cylinders 62 are not parallel to each other but are radial relative to the x-ray source 12 .

[0085] The material of the cylinder 62 must ensure that substantially all of the primary x-rays 32 are absorbed, and further ensure that it does not generate any secondary x-ray emission or cause any additional scattering. To meet these requirements, chemical elements with medium atomic numbers Z are preferred, such as materials with Z of 20 to 34. The cylinder 62 may also have a multilayer structure with a core of high Z material and an outer layer of medium Z material. High Z materials absorb x-rays most efficiently, and any secondary x-ray emission from the core material is efficiently absorbed by the outer layer without inducing further secondary emission.

[0086] The thickness or height of cylinder 62 depends on the energy of the x-rays, with higher energies requiring thicker cylinders. In lower energy x-ray imaging, such as in mammography, cylinder 62 may be a thin disk.

[0087] As described below, the detector assembly 14 described above is used to remove the scatter 34 from the image. A low resolution scatter image is read from a selected location 54 of the rear detector 26. A low resolution composite image is read from a selected location 56 of the rear detector 26 that receives the primary x-rays 32 and the scatter 34 and uniformly covers the entire image plane of the rear detector 26 and is close to the selected location 54. The scatter-only image is extended to the selected location 56 by interpolation. Due to the physical properties of the scatter 34, the interpolation does not introduce significant errors. As long as there are a sufficiently large number of data points, the error due to interpolation is negligible compared to other sources of error (such as statistical fluctuations in the number of x-ray photons).

[0088] The scatter-only interpolated image is subtracted from the low resolution post-synthesized image to produce a low resolution primary x-ray image at the selected position 56. A low resolution primary x-ray front detector image is calculated from the front detector position 40 aligned with the selected rear detector position 56. A low resolution scatter image is determined by subtracting the low resolution primary x-ray back detector image from the low resolution front detector synthetic image. A high resolution scatter image is calculated by interpolating the low resolution scatter image. The high resolution scatter image is subtracted from the high resolution synthetic image to produce a high resolution primary x-ray image.

[0089] like Figure 1 As shown, the above-described beam selector 24 must remain fixed relative to the emission location 16 because the cylinder 62 must remain aligned with the source x-rays 30 from the emission location 16 in order to function properly. The detectors 22, 26 do not have to move, but would need to move if the beam selector 24 were fixed to the detectors 22, 26. If the emission location 16 moves a small enough distance to adequately align the cylinder 62 with the source x-rays 30, then the beam selector 24 does not have to move.

[0090] Another scatter cancellation method is described in detail in U.S. Patent Nos. 5,648,997 and 5,771,269. Figure 3 As shown, the detector assembly 14 is a three-layer structure of a front 2D detector 22 closest to the source 12, a 2D beam selector 24, and a rear 2D detector 26. A combination of primary x-rays 32 and scatter 34 reaches and passes through the front detector 22. The beam selector 24 allows only the primary x-rays 32 to pass through to a selected location 38 of the rear detector 26.

[0091] In the simplest configuration, the beam selector 24 is a sheet of x-ray absorbing material 46 having a large number of through holes 48. The holes 48 are made so that their axes are aligned with the direction of travel of the primary x-rays 32, which means that, since the x-rays are emitted essentially from a point source, the holes 48 are not parallel to each other but are radially aligned with the x-ray source 12.

[0092] Due to this alignment, the aperture 48 allows all x-rays traveling along the axis of the aperture 48 to pass, while almost all x-rays traveling in a direction slightly offset from the aperture axis are completely absorbed by most of the material of the beam selector 24. Therefore, only the primary x-rays 32 reach the rear detector 26. Because the aperture 48 will always have a finite size, a small portion of the scatter 34 will reach the rear detector 26. However, as long as the aperture size 48 is small and the thickness of the beam selector 24 is large enough, this portion of the scatter 34 can be controlled to be negligibly small compared to other error sources.

[0093] Preferably, the holes 48 are as small as possible. If the holes 48 are too large, they will not prevent enough scatter 34 from reaching the rear detector 26. Preferably, there are as many holes as possible in the beam selector 24. The more holes 48, the higher the measurement accuracy at the rear detector 26.

[0094] The material of the beam selector 24 must ensure that all scatter 34 is absorbed and that, apart from the primary x-rays 32 passing through the aperture 48 , no other radiation (including scatter 34 and secondary emissions caused by the primary x-rays 32 or scatter 34 ) reaches the rear detector 26 .

[0095] As described below, the above-described detector assembly 14 is used to remove scatter 34 from an image. A low resolution primary x-ray image is read from a selected position 38 of the rear detector 26. A high resolution composite (primary x-ray 32 and scatter 34) image is read from the front detector 22. A low resolution front detector composite image is read or calculated from a front detector position 40 aligned with the selected rear detector position 38. A low resolution front detector scatter image is determined by subtracting the low resolution rear detector primary x-ray image from the low resolution front detector composite image. A high resolution front detector scatter image is calculated by interpolating the low resolution front detector scatter images. The high resolution front detector scatter image is subtracted from the high resolution front detector composite image to produce a high resolution primary x-ray image.

[0096] Because only selected locations 38 on the rear detector 26 are used, an alternative configuration for the rear detector 26 is to place one or more detector cells at the bottom of each well 48 rather than leaving the entire 2D detector largely unused.

[0097] The beam selector 24 described above must remain fixed relative to the emission location 16 because the aperture 48 must remain aligned with the source x-rays 30 from the emission location 16 in order to function properly. The detectors 22, 26 do not have to move, but would need to move if the beam selector 24 were fixed to the detectors 22, 26. If the emission location 16 moves a small enough distance to adequately align the aperture 48 with the source x-rays 30, then the beam selector 24 does not have to move.

[0098] If there are only a very small number of emission locations 16, the beam selector 24 can have a set of apertures 48 with a different focus for each emission location 16. The apertures 48 for different sets have different selected positions 38 so that the scatter 34 produced by one source location does not affect the signal from other source locations. This configuration of the beam selector 24 does not have to move with the emission locations 16.

[0099] The subsequent beam selector 24 has an adjustable focus, so that the beam selector 24 does not have to be moved with the movement of the emission position 16.

[0100] Figure 4 The beam selector 24 includes an x-ray absorbing material having a plurality of through holes 70. Each hole 70 is formed by a rigid hollow tube 76 made of one or more x-ray absorbing materials in layers 78 having different x-ray energy absorption characteristics. Figure 4In the embodiment of the present invention, the tube 76 can include three different layers 78a, 78b, 78c of x-ray absorbing materials. The multiple x-ray absorbing materials provide effective absorption for multi-energy systems or single energy systems, where the energy distribution is over a wide range, such as 15KeV to 500KeV. Possible materials include tungsten (W), tin (Sn), and copper (Cu). When the materials are selected to absorb most effectively at different energy levels, the thickness of the tube wall 78 can be minimized.

[0101] The region 80 between the tubes 76 includes a compressible x-ray absorbing material, such as an elastomer mixed with an x-ray absorbing material. As with the tube wall 78, the region 80 may include multiple layers having different x-ray energy absorbing properties. Figure 4 8, region 80 includes three different layers 80a, 80b, 80c of x-ray absorbing materials, for example, an elastomer mixed with tungsten 80a, an elastomer mixed with tin 80b, and an elastomer mixed with copper 80c. The ratio of elastomer to x-ray absorbing material must be selected so as to maintain the compression characteristics of the elastomer and the absorption capacity of the x-ray absorbing material. Typically, the ratio of elastomer to x-ray absorbing material is in the range of 1:1 to 1:4.

[0102] Alternatively, if Figure 5 As shown in FIG. 1 , the region 80 between the tubes 76 is blocked on both sides by plates 92 of polymer, elastomer, smart metal, and / or some combination thereof. The region 80 is filled with beads 90 or powder of x-ray absorbing material. The thickness of the beads 90 or powder is adjusted as needed to attenuate x-rays as desired.

[0103] Alternatively, smart metal and / or smart wire connects the tube 64. The smart metal and / or wire can be stretched, compressed or bent in at least one dimension under computer control.

[0104] Typically, in their resting state, the apertures 70 are parallel to each other and have no focal point. Figure 6 As shown in , to produce a focal point, the top edges 86 of the four sides 84 are moved inward. Assuming that the four sides 84 are of equal length and the compressibility of the region 80 is constant throughout the beam selector 24, moving all four edges 86 by the same amount will produce a focal point above the center of the beam selector 24. The distance of the focal point will depend on the amount of displacement. By changing the amount of displacement of each edge 86 individually, the position of the focal point can be changed in three dimensions. In order to achieve a focal point (as opposed to a focal line), at least two adjacent edges 86 must be moved.

[0105] Alternatively, the regions 80 between the tubes 76 are not x-ray absorbing. As long as the tube walls 78, which are composed of one or more x-ray absorbing materials, substantially block all scatter 34 from the selected locations 38, the regions 80 need only be filled with a polymer, elastomer, and / or any material that can provide adequate structural support.

[0106] Another example of a beam selector is a focusing or parallel grid, a wire grid or a cross grid formed by two wire grids. The wire grid is typically composed of alternating lines of material and spaces that absorb x-rays or materials with non-x-ray absorbing properties and low x-ray absorbing properties. The x-ray absorbing material lines block the primary x-rays and the alternating spaces allow the transmission of the primary x-rays. The cross pattern or wire grid form can be a variation of the above-mentioned 2D beam selector, where the layout through which the primary x-rays pass is determined by the area where the low x-ray absorbing material or non-x-ray absorbing material is placed. The focusing filter grid is a grid area through which the primary x-rays pass designed so that the geometry of the x-ray fan beam is taken into account. The focus of the primary x-ray area is aligned with the x-ray fan beam channel so that the primary x-rays are transmitted at the distribution area on the detector. The configuration described here is a slight variation of the previously described beam selector using a grid commonly used in an x-ray collimator.

[0107] exist Figure 7-13 Another embodiment of the beam selector 24 with an adjustable focus is shown in . The beam selector 24 allows only the primary x-rays 32 to pass through to a selected location 38 of the rear detector 26 .

[0108] like Figure 7 As shown in FIG. 1 , in one configuration, the beam selector 24 includes two or more rigid x-ray absorbing plates 100, 102 having a plurality of rigid hollow tubes 104. The tubes 104 are formed of x-ray absorbing materials or polycapillaries that can perform total internal reflection of the beam at a limited critical angle or non-x-ray absorbing materials that do not produce scattering, as long as such an arrangement does not allow scattering to pass through the tubes 104 and the upper plate 102 and impinge on detectors at the bottom of other tubes. The tubes 104 can be formed of x-ray absorbing materials or polycapillaries that can perform total internal reflection of the beam at a limited critical angle or non-x-ray absorbing materials that do not produce scattering, as long as such an arrangement does not allow scattering to pass through the tubes 104 and the upper plate 102 and impinge on detectors at the bottom of other tubes. Figure 4 The beam selector implementation scheme is formed as described above.

[0109] The beam selector embodiment described above that allows only primary x-rays 32 to pass through to selected locations 38 of post detector 26 uses a hollow tube 104 having x-ray absorbing walls. The present disclosure contemplates that alternatives to tube 104 may be used.

[0110] Optionally, for Figure 7In the embodiment shown in FIG. 1 , beads or powder of x-ray absorbing material are added to a bag made of metal or polymer that surrounds each tube 104 just above the rear detector 26. The thickness and width of the bag are designed to block substantially all (99.99%) of the primary x-rays 32 and scatter 34 from reaching the rear detector 26 surrounding the tube 104, thereby creating an area without any x-ray signal around the selected location 38.

[0111] Optionally, for embodiments employing elastomers, beads and / or powder of x-ray absorbing material without the elastomer may be used between the plates 100 , 102 .

[0112] In one configuration of an adjustable focus beam selector, such as Figure 8 As shown in , the substrate 100 has an array of apertures 106 at a given pitch, and the focusing plate 102 has an array of apertures 108 at a pitch slightly smaller than the pitch of the substrate 100. For example, if the substrate pitch is 10 mm, the focusing plate pitch may be 9.8 mm.

[0113] The base plate aperture 106 is slightly larger than the diameter of the tube 104 so that the tube 104 can be tilted within the aperture 106 to an angle of about 11° from vertical to obtain a focal length of 500 mm. The focusing plate aperture 108 is slightly larger than the diameter of the tube 104 so that the tube can slide within the aperture 108 and tilt within the aperture 108 to an angle of up to about 11° from vertical to obtain a focal length of 500 mm.

[0114] When the focusing plate 102 is centered on the substrate 100 so that the central tube 104 is vertical, the focal point is directly above the center of the focusing plate 102. Figure 9-11 As shown in FIG, vertically moving the focusing plate 102 changes the vertical position of the focus. Fig.13 and Fig.13 As shown in FIG. 1 , horizontal movement of the focusing plate 102 changes the horizontal position of the focus.

[0115] In one configuration, the beam selector 24 has an array of total internal reflection elements (eg, a polycapillary catheter) in which only x-ray beams that strike the catheter within a very narrow critical angle range pass to the post detector 26 .

[0116] exist Fig.14 and Fig.15 Another example of a beam selector 24 with an adjustable focus is shown in FIG. In this embodiment, the tube is eliminated and perforations 116 are located in a plurality of stacked plates 114 of x-ray absorbing material having a thickness designed to absorb substantially all x-rays. The perforations 116 are aligned to form holes 118 that transmit primary x-rays 32 to the rear detector 26. The plates 114 are moved relative to each other by 2D actuators to shift the focus.

[0117] In another configuration, the beam selector 24 includes x-ray optics such as an array of diffraction elements (such as statically and spatially tunable or modulated MEMs or deformable MEMs) and crystals (such as spatially tunable crystals for ultrasonic modulation of x-ray transmission in a selected area) or a diffraction grating and associated x-ray optics.

[0118] As the direction of the incident x-ray beam striking the crystal changes, the modulation may change accordingly or remain the same to allow the primary x-rays to pass through.

[0119] The beam selector 24 may have an array of refractive elements, such as x-ray optics or an x-ray lens assembly.

[0120] Primary x-rays or scatter can be separated based on the critical angle of the incident x-ray beam. One beam can be within the critical angle, while the other beam can be outside the critical angle and combined with the use of x-ray optics. For example, using a refractive x-ray lens as part of a beam selector, primary x-rays or scatter can be separated based on the acceptance angle of the incident x-ray beam. In some cases, such a beam selector can be part of the front window of the rear detector, which allows x-rays from a selected area to pass through and be detected, thereby separating the primary x-rays and scatter. Alternatively, the direction of the signal received at the rear detector corresponds to the incident angle of the x-ray beam, and the primary x-rays and scatter are distinguished at the rear detector using the known x-ray emission position, geometry, and predicted incident x-ray beam angle.

[0121] The above configurations using a scatter blocking beam selector can also use a full 2D rear detector 26. In these configurations, detector cells 28 not aligned with aperture 48 are not used because they are blocked by beam selector 24 from receiving any x-rays.

[0122] Alternatively, if Fig.18 As shown in , the rear detector 28 is not a full 2D detector, but rather includes a group 42 of one or more detector cells 28, where each group 42 is located at the bottom of a beam selector aperture 48.

[0123] A variation of the configuration including a beam selector sandwiched between two detectors is to use a dual detector layer. In one instance, the front detector selectively transmits primary x-rays or scattering while being able to detect a projected image including primary x-rays and scattering. The pixel area as a transmission area includes at least one transmission pixel. In one instance, the front detector has a detection plate pattern in which the primary x-rays can pass through alternating transmission areas and opaque areas. The alternating pattern and size of the two areas are determined by the requirements of the application and what percentage of scattering needs to be removed or separated from the primary x-rays. In one instance, below the transmission area including one or more pixels, a single diode or multiple diodes can be used as a detector, with one pixel in each diode. Alternatively, a small detector with one or more pixels can be used. Therefore, instead of a planar rear detector, it is not necessary to have a single detector, but rather multiple small detectors, each of which is smaller than the front detector.

[0124] In another configuration, each pixel of the front detector is partially transmissive and partially sensing. The rear detector captures the emission signal from the front detector.

[0125] In another variation, such transmissive or transparent features may be built into the rear detector. Thus, x-rays may be absorbed or transmitted in the rear detector prior to the sensing region of the rear detector.

[0126] Alternatively, such a detector assembly is constructed as one detector with built-in features and dual detection planes as described above.

[0127] Another variation of the beam selector uses a filter to reduce the proportion of the scatter that reaches the second detector layer, and the first sensor is connected to the filter to capture the primary x-rays and the scatter.

[0128] like Fig.14 and Fig.15 Another example of a beam selector 116 placed between the front and rear detectors, as shown in , includes two or more plates 114. Each plate includes an X-ray absorbing material (such as tungsten, copper, or an alloy). The thickness of each plate can be such that it can absorb almost all X-rays at one or more energy levels, whether alone or in combination. There can be spacers between the plates to maintain the distance between the plates. Optionally, an X-ray absorbing frame around the four sides of the plate not facing the detector is placed as a beam blocker.

[0129] Each plate may have holes of various shapes. If the first plate 114 is the plate closest to the front detector, the second plate 114, the third plate 114, the fourth plate 114, the fifth plate 114 may have corresponding holes of similar or larger size than the holes of the first plate 114.

[0130] In some cases, each plate 114 may be moved by one or more linear actuators to align the x-ray source with the holes distributed in each plate to allow primary x-rays to pass through.

[0131] Alternatively, if the hole in the plate closer to the rear detector is larger, the plate may not need to be moved. Only the area on the detector where the primary x-ray beam path is projected is used as the selected primary signal. Any x-ray signal outside the beam path will not be considered when obtaining a high resolution primary x-ray signal on the front detector. These areas of primary x-ray beam path projection can be predetermined by the relative position of the x-ray source to the detector and the position of the beam selector plate, or by measuring without an imaging object, but with a varied x-ray emission position corresponding to the imaging configuration of the imaging object.

[0132] X-ray sources and emission locations

[0133] The present disclosure uses an x-ray source 12 capable of emitting pulsed or continuous x-rays with controllable energy. Such an x-ray source may be a conventional x-ray tube x-ray source, a cold cathode x-ray source, a metal liquid jet, a laser Compton x-ray, a linear accelerator-based x-ray source, or a synchrotron or synchrotron-like x-ray source, a coherent or partially coherent x-ray source, a monochromatic source, a broad spectrum x-ray source, and / or an x-ray source based on a field emitter nanostructure.

[0134] Examples of x-ray sources include: a plurality of individually programmable electron emitting units for emitting an electron beam when an electric field is applied; an anode target that emits an x-ray beam when struck by an electron beam emitted from an x-ray source having a collimator.

[0135] Each electron emission unit may include an electron field emission material. Each electron field emission material may include a nanostructured material. The electron field emission material may include a plurality of nanotubes or nanowires. Examples of nanotubes (including carbon, boron and / or nitrogen) include at least one field emission material selected from sulfur and / or tungsten. Examples of nanowires (including silicon, germanium, carbon, oxygen, indium, cadmium, gallium, zinc, oxides and / or nitrides) may include at least one field emission material selected from silicides and / or borides.

[0136] Examples of portable field emitter nanotube-based x-ray sources

[0137] Portable X-ray Source

[0138] The present disclosure provides an x-ray source, an example of which is Fig.32 It includes

[0139] · An efficient, lightweight, miniaturized x-ray generator. For example, a vacuum-sealed field emission tube S-1. The S-1 may include a cold cathode x-ray tube;

[0140] An electrical energy storage device (e.g. a condenser or capacitor) for storing electrical energy for pulse operation S-3. S-3 can be built on a pre-stage and can operate at a much lower voltage (e.g. 5kV to 10kV).

[0141] Voltage amplifier S-2 (eg, high voltage pulse transformer) to provide high energy pulses, eg, 100 kV-150 kV.

[0142] The pulse duration can be controlled to be, for example, 0.1 ms to 10 ms. The corresponding current flowing in the tube can be 10 mA to 1 A to provide the desired energy for high quality x-ray imaging. The pulse width and current are determined by the capacitance of the capacitor, the inductance of the pulse transformer, and the parameters of the V-1 characteristic curve of the tube.

[0143] Flash x-ray sources can be based on the use of field emission tubes driven by, for example, a high voltage source providing a high current output to trigger a pulse transformer. Fig.31 As shown in , HV semiconductor devices, HV thyristor triggered pulse transformers or integrated gated bipolar transistors. Vacuum or gas type devices (such as thyristor spark gaps) are examples of high voltage (HV) devices that can provide high current output for HV pulse generators.

[0144] A high voltage thyristor or IGBT may be used as the switching device S-5. Two or more such HV devices may be connected in series to achieve an initial HV voltage (eg, a voltage of 5-15KV) required to provide a high current output.

[0145] In order to produce variable energy at the output of the x-ray source, different targets on a rotating anode are used, each target producing x-rays of a certain energy level.

[0146] The x-ray tube may be a cold cathode based x-ray tube, for example a field emission x-ray source comprising a plurality of programmable electron emission units, each of which may be focused by a conical transport anode target or a focusing device such as an electrostatic lens, an electro-optical focusing lens as described above. Figure 23-24C The door net shown in is optional.

[0147] The present disclosure provides an x-ray source that includes major components with typical parameters: including, for example, a 2.5 kV DC power supply, a high voltage current storage means (such as a capacitor with a capacitance, for example, 2 μF), an electronic trigger circuit, a high voltage pulse transformer (in one case, encapsulated in Sylgard Silicone), and an x-ray tube (which can be a cold cathode x-ray source). When HV=50 kV, the total energy stored in the capacitor for generating a single x-ray pulse can be 30 J. The size of the entire x-ray source can be less than or approximately 8"×8"×16" and weigh approximately <30 lb. Smaller sizes are possible depending on the selection of each component. The x-ray energy level can be from 125 KV to 250 KV.

[0148] Such x-ray sources may be used in two-dimensional imaging systems and may have portable capabilities.

[0149] To provide a tomography system having no moving parts, such as Fig. 20 As shown in , in a system having multi-dimensional imaging capability as described in the present disclosure, an electron beam or a charged particle beam can be manipulated by magnetic tools (such as magnetic plates or magnetic-based steering devices) or metal devices (such as electro-optic lenses).

[0150] The x-ray source device can produce single or multiple energies. It can be used in one or more of the systems described below.

[0151] Single, dual or multi-energy X-ray systems

[0152] · X-ray system with scattered and primary x-ray separation including hardware and software

[0153] X-ray multi-dimensional or 3D imaging system

[0154] · X-ray imaging systems for diagnostic, industrial and research applications.

[0155] Typical parameters of the source

[0156] Focus: 0.1mm to 10mm

[0157] Screen area: 60cm×60cm

[0158] Typical scanning points: 30×30 to 50×50, max.

[0159] Dwell time at one point: 0.01ms to 10ms

[0160] Typical time at one point: 1ms

[0161] For a complete set of images, it is determined by the detector frame rate.

[0162] For each imaging operation, source 12 may emit two or more consecutive x-ray pulses with controllable energies: a high energy pulse at an average energy level H followed by a low energy pulse at an average energy level L. Each pulse has a single reproducible energy spectrum including bremsstrahlung and discrete line emissions.

[0163] In another configuration, source 12 emits three consecutive pulses for each imaging operation: a high energy pulse with an average energy level H, followed by a medium energy pulse with an average energy level M, followed by a low energy pulse with an average energy level L. Each pulse has a single substantially constant energy spectrum.

[0164] In another configuration, source 12 emits a pulse having two or more energy peaks, each energy peak being separated in time from the other energy peaks during the pulse duration.

[0165] In another configuration, source 12 emits broad spectrum pulses.

[0166] Each detector or x-ray measurement assembly including a detector may be energy sensitive, such as a photodiode array or an energy sensitive detector or an x-ray spectrometer.

[0167] Movement of the X-ray emission position

[0168] The x-ray emission position can be moved by mechanical, electrical and / or magnetic means.

[0169] refer to Figure 1 and Fig.19 , the x-ray emission location 16 may be movable relative to the object 2 in a plane 18 that is parallel to the detector assembly 14. Alternatively, the present disclosure contemplates that the emission location 16 may be movable relative to the object 2 in a plane that is perpendicular to the detector assembly 14 or in a plane other than the planes that are parallel and perpendicular to the detector assembly 14. Mechanical, electrical, or magnetic mechanisms provide the desired motion.

[0170] In another configuration, the mechanism moves the emission location 16 angularly, linearly, or a combination of both. The movements are preferably performed to resolve unknown pixels in the third dimension in the target area 4 within the object 2, preferably at integer multiples of the pixel pitch, while minimizing the introduction of new unknown pixels in each movement, and minimizing the introduction of the total number of new unknown pixels for the complete derivation of the unknown pixels in the third dimension of the target area 4.

[0171] To minimize total imaging time and radiation exposure, the present disclosure contemplates (although does not require) that the mechanism rapidly provide for movement of the emission location 16. For example, the mechanism may provide for such movement in increments that are integer multiples of the pixel pitch (the distance between adjacent detector elements 28).

[0172] The present disclosure contemplates that the object 2 is physically moved relative to the emission location 16, particularly in applications (such as industrial applications) in which the object 2 is already in motion when being imaged. To minimize the total imaging time and radiation exposure, each movement (whether angular or linear) resolves unknown pixels in the third dimension (preferably at an integer multiple of the pixel pitch), and at the same time, introduces new unknown pixels in the process, in addition to the region of interest, which will also require consideration of the number of measurements required to resolve such unknown pixels.

[0173] One example of an x-ray source and moving system is a metal, graphene, silicon, or carbon nanotube-based field emitter, which is driven by an applied electric field rather than by temperature, also known as a "cold cathode." In a CNT, the current is precisely and instantaneously controlled by an applied voltage.

[0174] CNT emitter c-3 can be used in an x-ray tube that includes two or more field emitter nanotubes (such as carbon nanotubes) arranged vertically on a conductive substrate. In one configuration, the width of the carbon nanotube is in the nanometer range. The tip of the carbon nanotube is where the emission occurs. In one example, Fig.23 Arranged CNTs as shown in . A grid or gate mesh structure c-2 connected to electrodes inside the tube wall is placed a short distance above the tip of the CNT. A voltage gradient can be applied externally between the grid mesh and the substrate. The voltage generates a very strong electric field at the tip of the CNT. The electric field intensity concentrated at the tip of the CNT forces field emission of negatively charged electrons to occur at the tip of the CNT. When exposure is turned on, electrons are emitted from the tip of the CNT and fly towards the grid mesh c-2. Accelerated primarily by the high voltage at the anode, x-rays are produced when the electrons hit the anode c-1. An electro-optical focusing lens c-4, which can be internal, can be used to dynamically adjust the focal spot size of the x-ray emission or move the focal spot on the anode to a different position.

[0175] like Fig.24A As shown in , different regions of the CNT emitter can be activated and combined with the use of an electro-optical electrode c-4 to control the electron beam to adjust the size of the focus of the electrons c-5 on the anode.

[0176] To control the size of the electrons at the focus, other types of electrostatic or electromagnetic lenses (such as electromagnetic coils, Einzel lenses, quadrupole lenses, magnetic lenses, or multipole lenses) can be used.

[0177] Additional electromagnetic means (e.g. electromagnetic coil c-6) can be used to steer the beam so that the x-ray beam can be emitted from different positions on the anode from the XY plane parallel to the detector. In another embodiment, for electron beam steering, a set of magnetic plates or metal plates can be used.

[0178] In one configuration, such as Fig.24A , 24B and 24C (a different embodiment of this configuration), the CNT emitter element c-3 includes regions c-7, each of which includes one or more field emitter nanotube emitters. Each region can be activated and deactivated independently of each other. The electron beam originating from one or more field emitter nanotube emitters can be manipulated electronically by electro-optical means, or magnetically by a magnetic plate, or electromagnetically by an electromagnetic coil c-5, so that its focus on the anode can move its position in a programmable manner. For example, by using two or more such regions, all x-ray emission locations on the anode can be extended in area or distance so that the pattern of x-ray emission locations can be continuous over the entire x-ray emission area on the anode.

[0179] Specific reference is made to systems using a beam selector, such as beam selector 24. Some beam selector embodiments must remain fixed relative to the emission location 16 because they have a fixed focus, while other beam selector embodiments do not have to remain fixed relative to the emission location 16 because they have an adjustable focus.

[0180] Several different mechanisms for providing a mobile transmit location 16 and optionally a mobile detector assembly 14 are described below.

[0181] In one scheme, two or more x-ray sources 14 are located at different positions in plane 18 and pulses are emitted sequentially from these positions. Detector assembly 14 is fixed. For this scheme, beam selector 24 must have multiple fixed focal spots or adjustable focal spots.

[0182] In other schemes, a single x-ray source 12 sequentially emits x-ray pulses from different locations on plane 18. This disclosure contemplates several different configurations by which this may be accomplished.

[0183] In one configuration, a two-dimensional actuator physically moves the x-ray source 12 and the x-ray detector assembly 14. Preferably, the actuator can move the x-ray source 12 and the x-ray detector assembly 14 by an integer multiple of a detector pixel pitch in the plane 18 at or faster than the frame rate of the detector assembly 14. For this configuration, the beam selector 24 can have a fixed focus.

[0184] In another configuration, the two-dimensional actuator physically moves only the x-ray source 12. Preferably, the actuator can move the x-ray source 12 in a plane parallel to the detector assembly 14 in increments of a minimum integer multiple of the pixel pitch, which results in planar motion of the x-ray beam measurement position relative to the previous position by one pixel pitch at or faster than the frame rate of the detector assembly 14. For this configuration, the beam selector 24 must be aligned with the emission position 16. In some configurations, the beam selector 24 may need to have an adjustable focus.

[0185] In another configuration, the two-dimensional actuator physically rotates only the x-ray source 12 so that the emission location 16 moves in an arc. Preferably, the actuator can rotate the x-ray source 12 by an angle equal to the angle along the arc at or faster than the frame rate of the detector assembly 14 to simulate a planar motion of one pixel pitch, or an integer multiple of one detector pixel pitch. For this configuration, the beam selector 24 must be aligned with the emission location 16, and in some configurations, its focus may need to be adjusted.

[0186] In another configuration, such as Fig.19 As shown in FIG. 1 , the x-ray source 12 is a single x-ray source 202 , and the x-ray beam is moved to different emission locations 16 using, for example, total internal reflection from a polycapillary 204 .

[0187] Among other mechanisms, methods are used to deflect the electron beam within the x-ray source 12 to impinge on different locations on the anode, thereby causing the x-ray beam to be emitted from different emission locations 16 .

[0188] In one configuration, such as Fig. 20 As shown in FIG. 1 , a changing magnetic field generated by, for example, a solenoid coil 212 connected to the housing of an x-ray tube 210 deflects the x-ray beam. The energized coil 212 generates a magnetic field and associated Lorentz force on the electron beam in the x-ray tube 210, thereby moving the impact point on the anode target 214 from which the x-rays are emitted. The emission location 16 moves due to the displacement of the focus of the cone beam on the anode 214. The result is that the emission location 16 moves from one location to another. Careful control of the coil 212 can produce movements as small as one pixel pitch in one or two dimensions.

[0189] In another configuration, the electron beam is deflected as it passes through a charged metal plate. The direction of the deflection depends on the polarity and charge of the plate.

[0190] In another configuration, a light source such as a light emitting diode (LED) or a laser is used as a light source to generate an electron beam, which is then amplified by a multiplier tube. An optical deflector (such as an optical device or a reflector) and an acousto-optic deflector are used to deflect the light. An ultrafast laser can be used to generate an ultraviolet emitter that emits ultraviolet light, a photocathode operably connected to an ultraviolet light emitting diode that emits electrons, an electron multiplier operably connected to a photocathode that multiplies incident electrons, and an anode operably connected to an electron multiplier configured to generate x-rays. The ultraviolet emitter can be manipulated at different angles to control the output of the electron beam, which in turn changes the direction or position of the x-ray beam emitted from the anode.

[0191] In another configuration, irradiating an array of metallic components (such as nanowires) with intense femtosecond laser pulses produces high brightness picosecond X-ray pulses. The emission location 16 can be moved by using an optical manipulator to change the impact location of the laser beam on the metallic component.

[0192] Multiple photocathodes or multipliers can be used to collect the steered laser beam and output the electron beam. In some cases, the electron beam can be rapidly steered via electronic, magnetic, optical and / or crystal plus ultrasound or other means. One way to do this is to use a 2D array of collimators with holes that are integer multiples of the pixel pitch, raster scanning the x-ray beam using different mechanisms including magnetic tools.

[0193] In another configuration, the X-ray source includes micron-sized metal X-ray emitters that can be modulated and switched on and off to control the emission location.

[0194] In another configuration described in US Patent Publication No. 2010 / 0189223A1, the x-ray source 12 is a digitally addressed x-ray source flat panel in which one or more emitters are located in each pixel on the 2D flat panel.

[0195] In another configuration, ultrasound can modulate an x-ray beam in space and time. For example, space-time modulation of an x-ray beam is accomplished by total external reflection on a YZ cut of a LiNbO / sub 3 / crystal modulated by a surface acoustic wave. X-ray diffraction is determined by the amplitude and wavelength of the surface acoustic wave. The x-ray beam is directed at the crystal, and the crystal dynamically manipulates the beam based on how the modulating acoustic wave changes the diffraction properties of the crystal. The output position of the x-rays from the crystal can be changed. For example, the x-ray beam can be modulated to emerge from the crystal at different locations on the XY plane.

[0196] In another configuration, coherent x-rays can be produced using relativistic electron beams with current modulation at the nanometer scale and below. The current modulation is produced by diffracting relativistic electrons in an ideal silicon crystal, accelerating the diffracted beam and imaging the crystal structure, and then transferring the image to the time dimension via emissivity exchange. The modulation period can be tuned by adjusting the electron optics after diffraction. The tunable longitudinal modulation can have a period as short as a few angstroms, enabling the generation of coherent hard x-rays from the device based on inverse Compton scattering with a total length of several meters.

[0197] The spatial position where the electron beam strikes the anode can be modulated by manipulating the position of the laser beam from the laser pump, which causes the change position of the x-ray emission position. The present disclosure also contemplates the use of combined imaging systems, such as interferograms, partial coherence and coherent x-ray imaging systems. For example, in a system used in a phase contrast imaging method, a detector upstream system based on coherent x-ray imaging or based on an interferogram is modified to achieve a change in the x-ray emission position or to produce a change in the x-ray source. For example, a source grating (where x-rays are divided into multiple sources upstream of an x-ray interferometer) can be used for the generation of x-ray emission positions. This can be achieved by a tunable grid, where the selected x-ray emission position is blocked by the x-ray absorption zone in time. Such a tunable grid system can be designed into the source grating hardware, or it can be separate. Another embodiment is that, downstream of the source, by using a blocking mechanism similar to that at the source, or by moving or modifying any hardware downstream of the source at any position between the source and the detector, the x-ray emission position is changed to achieve the ultimate purpose of measuring the target area using a changing irradiation path of the target area at different times. For example, the G1 and G2 gratings can be modified.

[0198] Another embodiment of an x-ray interferometer is a crystal interferometer, or an interferometer based on crystal elements.

[0199] like Fig.21 As shown in , an example of crystal-based crystal interferometry or x-ray interferometry consists of three beam splitters 150, 152, 154 arranged in parallel to each other in a Laue geometry. An incident beam 30 from an x-ray source 12, which is usually collimated and filtered before by a monochromator (Bragg crystal) 156, is split by Laue diffraction at the first crystal 150 into two coherent beams, namely a reference beam 160 that remains undisturbed and a beam 162 that passes through the object 2. The second crystal 152 acts as a transmission mirror and converges the beams 160, 162 toward each other. The two beams 160, 162 meet at the plane of a third crystal 154, sometimes referred to as an analyzer crystal, and produce an interference pattern, the form of which depends on the optical path difference between the two beams 160, 162 caused by the object 2. The interference pattern is detected by the x-ray detector 14 behind the analyzer crystal 154.

[0200] By moving one of the hardware elements (eg, Bragg crystal 156, x-ray emission position 16, or object 2) and recording projections from different illumination paths using the above method, a 3D distribution of the refractive index of the object and thereby a tomographic image of the object can be retrieved.

[0201] In contrast to the following methods, with a crystal interferometer the phase itself is measured, rather than any spatial variation of it. In order to retrieve the phase shift from the interference pattern, a technique known as phase stepping or fringe scanning is used. A phase shifter (having the shape of a wedge) is introduced into the reference beam. The phase shifter produces straight interference fringes with regular intervals, the so-called carrier fringes. When an object is placed in the other beam, the carrier fringes are shifted. The phase shift caused by the object corresponds to the displacement of the carrier fringes. For different shifts of the reference beam 160, several interference patterns are recorded, and by analyzing them, the phase information modulo 2π can be extracted. This mode of phase removal. These techniques can be used when the signal-to-noise ratio of the image is high enough and the phase change is not too abrupt.

[0202] As an alternative to the fringe scanning method, the Fourier transform method can be used to extract the phase shift information with only one interferogram, thereby shortening the exposure time, but this has the disadvantage of limiting the spatial resolution by the spacing of the carrier fringes.

[0203] "Coherence contrast x-ray imaging" is another implementation of an interferogram where, instead of a phase shift, the change in the degree of coherence caused by the object is related to the contrast of the image.

[0204] Alternatively, the Laue crystal can be replaced by a Bragg crystal so that the light beam does not pass through the crystal but reflects off the surface.

[0205] In some cases, two lenses are used instead of one to increase the field of view.

[0206] It should be noted that in most, if not all, phase contrast measurement and interferometry methods, the amplitude of the x-ray input beam or the intensity of the x-ray input beam may be modulated for some measurements.

[0207] Crystal-based interferograms or analyzers, where the position of the beam splitter can be manipulated using modulation by ultrasound or other energy or electronic methods. For example, a liquid crystal-based crystal analyzer can be used to adjust the beam split position to produce different illumination paths.

[0208] The present disclosure can be implemented in a portable form, such as a handheld device or a flash drive. Another example of a portable form of the present disclosure is a foldable system suitable for on-site inspection or diagnosis or image guidance or material characterization.

[0209] Other advanced hardware

[0210] One aspect of the present disclosure includes using

[0211] Microelectronic mirror (MEM) devices used as 1) static or dynamic or tunable diffraction gratings in interferometers, or as 2) primary modulators for generating high spatial frequency x-ray beams, or as 3) collimators by adjusting the critical angle of the incident x-ray beam.

[0212] Crystal or liquid crystal based devices used as 1) static or dynamic or tunable diffraction gratings in interferometers, or as 2) primary modulators for generating high spatial frequency x-ray beams to separate scattered and primary x-rays, or as 3) collimators by adjusting the critical angle of the incident x-ray beam.

[0213] method

[0214] Elements of the present disclosure include methods for rapid, high-resolution 3D image reconstruction of a region of interest in an object by moving the location of an x-ray source emission location relative to a detector by the smallest possible increment (e.g., pixel increment) to only a small number of locations in an area of ​​approximately n2 in the XY plane to obtain image data necessary to resolve n2 unknown pixels along the Z axis, where n is the highest number of units on the x or y axis describing the x-ray emission location in the 2D plane. This allows for systems that require fewer 2D projection images, fewer motion requirements, or fewer motion movements, or a combination of these elements, which means that less time and less radiation exposure is required to reconstruct a multi-dimensional image compared to the prior art.

[0215] In x-ray measurements using a 2D detector, the unit measure of n may be the unit measure of the pixel pitch of the detector.

[0216] In some cases, the relative positions of adjacent x-ray emission locations may be less than one pixel pitch, yet still produce measurements for the projection path that can be used to resolve unknown voxels on the z-axis perpendicular to the detector.

[0217] In some cases (such as in an x-ray microscopy device), the resolution of the camera (and thus the pixel pitch) may be much larger than the resolution achieved in the measurement unit or in the object. For example, in the nano or sub-nano range. As a result, the distance between the measurement units of n or adjacent x-ray emission positions can be within the resolution range to be achieved in the object, for example, at the sub-nano level or a single-digit nano level, or as small as allowed by the achievable resolution. This means that instead of the pixel pitch that measures the distance between adjacent x-ray emission positions, this distance can be many times smaller than the pixel pitch of the illumination camera. In some cases, as small as the smallest x-ray wavelength, for example, 0.01 nm.

[0218] The present disclosure also describes a method in which the object moves relative to the x-ray source and the detector (such as a part on an assembly line). When the part moves through the assembly line, x-ray 3D measurement can be completed by correcting and registering the x-ray emission positions (i.e., the elements of the detector) relative to the position of the part. 3D image acquisition can be achieved regardless of the unknown volume introduced by the movement of the part. The movement of the part can also be used as part of the measurement along the z-axis to resolve unknown voxels. The number and position of the x-ray emission positions can be determined based on a similar strategy. The goal is to minimize the total area of the movement and minimize the movement distance so that the depth or z-axis of the new unknown volume introduced during the process of resolving the unknown voxels in the target area is minimized.

[0219] The method includes the following elements:

[0220] Determine the number of 2D images required to reconstruct the desired 3D image.

[0221] For example, if the 2D detector array has m×n detector units, then any number p of 2D images, where p < n and p < m, and p is an unknown variable of the third axis, which > 3. This results in p 2D images, each image having m×n pixels.

[0222] The basic method is to solve a system of linear equations with m×n×p variables and m×n×p equations. The current method does not assume that each voxel in the target area of the object is a cube, that is, each side of each voxel is of the same length, D x = D y = D z . As Fig. 22 schematically shown in, the current method is applicable to the case where one side in D z is not equal to D x and D y .

[0223] When the x-ray emission position 16 moves by one pixel pitch in the x or y direction parallel to the detector relative to the position of the detector, the new emission position can generate an x-ray beam to illuminate the target area with a different projection path from the previous position. This means that in each projection path, there will be voxels with different spatial positions within m×n×p (m, n, p) in the projection path, which results in different x-ray measurement positions on the detector.

[0224] like Figure 1 , Fig.14 and Fig.15 As shown, when such positions (i, j) on the detector are associated with x-ray emission positions 16, which are points on the source 12, different positions on the detector measure the attenuation signal x of the projection path signal within the volume of the target area when the object is placed in the irradiation path, and each measurement is associated with the relative position of the x-ray source and the detector, as determined by the previously derived geometric information. Where each projection path consists of P voxels, each voxel contains its specific attenuation coefficient.

[0225] In a capacity of m×n×p, where p is the third axis thickness or variable in the region of interest. The different x-ray source emission positions are varied p times to produce different 2D projection images such that each pixel on the detector measuring a projection line signal from the region of interest contains a unique set of pixels with a fixed spatial relationship between pixel elements. Each 2D image comprising at least m×n measurements is measured p times, resulting in m×n×p known measurements. This data set is then used to resolve unknown voxels in the m×n×p space, which are the variables responsible for producing different x-ray measurements at corresponding locations on the detector at different x-ray emission positions.

[0226] In the case where unknown pixels of an object are embedded in the capacity of known pixels of the object, the x-ray emission position can be shifted by a small fraction of the pixel pitch to resolve the unknown pixels by creating a projection path sampled at a finer step size, so that the projection path includes at least one unknown pixel and at the same time no new unknown pixels are introduced.

[0227] In addition, in cases where the resolution requirement is not as high as the detector pixel size, it is within the scope of the present disclosure to define the required resolution and the corresponding measurement resolution. For example, if the required resolution is 500 μm and each pixel on the detector has a pixel pitch of 100 μm, one aspect of the present disclosure is to move the x-ray emission position by 500 μm. When a 3D image acquired at 500 μm resolution is obtained for a region of interest, further measurements at a finer step size (e.g., 100 μm) can be used to resolve finer details in selected areas within the region of interest.

[0228] Furthermore, in cases where material composition is determined and structural landmarks and dimensions are derived using multi-energy material decomposition or using lower resolution 3D imaging methods, this information can be used to select one or more regions for further finer resolution imaging, either simply given or derived based on known facts.

[0229] The following general steps may be performed to determine a 3D image: (1) calibration; (2) 2D imaging; (3) 2D image scatter removal; (4) 2D functional imaging; (5) 3D / multi-dimensional image calculation; (6) 3D / multi-dimensional functional imaging; and (7) 3D / / synthesized 2D / multi-dimensional image presentation. Each step is optional, and the steps may be performed in a different order.

[0230] calibration

[0231] Before performing image acquisition of an object, a preliminary geometric relationship can be determined for each x-ray source position and detector without the object. Fig.30 As shown in , the sub-pixel or pixel transmission can be calculated for each cell (i, j) on the detector 22, where i, j represents the position of the pixel or area x, y on the detector 22 at which it receives the x-ray signal through the voxel on the projection path 1, 2, 3, ... 11, 12, etc. The pixel spacing is the distance between the x-ray source movement steps or the distance between adjacent x-ray emission positions. Xa (i.e., the pixel spacing of the detector) can be the same as Xc, which is the resolution or unit of measurement in depth or in an axis perpendicular to the detector. In some cases, Xa can be less than Xc (i.e., the required resolution Xc in the Z axis). The x-ray emission position moves in increments of Xc to achieve the desired resolution.

[0232] The basic approach is to solve a system of linear equations with m×n×p variables and m×n×p equations. Current CT methods assume that pixels have dimensions Xa=Xb=Xc, however, the present disclosure extends to the case where Xc is not equal to Xc. When viewing x-rays as they pass through a pixel, the current method takes a value of 1 or 0, 1 for rays passing through the pixel and 0 otherwise. In the present disclosure, before acquiring the target area, alignment is performed at each angle, and the x-ray emission position (i, j) receives signals through 1, 2, ... 12, and the transmission of each sub-pixel can be calculated. It is assumed that within each pixel, the transmission is uniform and proportional to the capacity.

[0233] Such geometric calculations can be done in advance and stored in a computer. Alternatively, a general formula can be derived for how to write the system of equations in a digital format.

[0234] Starting from a system of m×n×p equations, with m×n×p variables, for each direction of the projected x-ray source or position of x-ray emission, there are mn projection data points recorded by m×n detector elements. Each equation has m×n×p variables, and there are (m×n)×p equations, so the system of linear equations should be solvable by iteration or matrix methods.

[0235] In a preferred embodiment, if an object of a specific size is to be imaged, a thickness or size measurement of the region of interest in the Z direction can be provided before that time. This can be achieved by:

[0236] 1. User Input

[0237] 2. Data derived from, for example, mechanical measuring tools or

[0238] 3. Determine thickness by 2D x-ray measurement at multiple energies based on a database built from previous measurement data using the same or similar materials, or

[0239] 4. Combined with one or more 2D images in single energy or dual or more energies through simulation data

[0240] 5. X-ray measurements at two or more different emission positions, or

[0241] 6. Through one or more non-radiative sensors.

[0242] In addition, the position of the target region relative to the x-ray source and detector can be determined using techniques as described in 1-6.

[0243] For example, a component size of 2 cm in the xyz dimension marked with contrast agent, or a target area in a bone and its direct area for arthritis identification, a strain stress area of ​​a bone or a specific area of ​​a semiconductor assembly line, a target area in luggage for security inspection, a target area for detailed inspection of parts in an assembly line.

[0244] Based on Fig.30 The desired resolution Xc is shown in , and then the number and positions of x-ray emission positions are determined for 3D imaging of the object. Before irradiating the object from different x-ray emission positions, calculations or calculations and measurements can be performed to associate the relative x-ray source positions and pixel positions on the detector with their corresponding projection paths within the volume where the target region in the object is located. Thus, each projection path in the 3D dimension of the target region is associated with an x-ray source position and a pixel or pixel region on the detector, where the x-ray signal of such projection is measured.

[0245] After acquiring the 2D image, a system of equations with m×n×p variables is solved, m×n×p equations. Each emission position of the x-ray source produces an image of size m×n. Each element of the detector receives x-rays transmitted through a predetermined projection path, and some elements receive x-rays transmitted after attenuation at the target region in 3D space. There are a total of p third axis variables or unknown pixels that need to be resolved to provide a complete 3D image of the target region. For example, the total attenuation variable

[0246] Attenuation X 总的 Along any given projection path, the total number of pixels Z is

[0247] X 总的 =X1+X2…+X z (3)

[0248] like Fig.30 Each X is in

[0249] X1, X2...X Z Each X in

[0250] Corresponds to a unique sub-pixel or pixel in the m×n×p capacity in the destination area.

[0251] For example, when unknown pixels outside the region of interest are introduced into the measurement as the relative positions of the x-ray source and the detector move, there are problems with integrity. There are three cases. (a) When the region of interest of the object is well within the imaging region, the integrity of the 3D image is assumed because the linear equations generally give the correct solution. (b) When the region of interest extends beyond the imaging region in one dimension, there are problems that will be discussed below. (c) When the region of interest extends beyond the imaging region in two dimensions, there are also problems that are discussed further below.

[0252] Assume that region A is the target region, and region B is adjacent to region A. However, in order to obtain projection data for region A, we must process data in region B. Region A is surrounded by region B by performing a two-step imaging process in which the x-ray source is moved differently, or if the x-ray emission position is moved differently due to the manipulation of the electron beam to scan the anode target at different positions, a two-step scan is performed. This generates x-rays at different positions. The information in region B can be accurately obtained without further expansion to a larger area. The method of the present disclosure allows minimization of the x-ray measurements required to reconstruct a multi-dimensional image. For example, as Fig.16 As shown in , bidirectional movement or raster scanning is used in the 2D area to obtain projection images along the X direction and the Y direction, and the total projection of NX data points and NY data points on the 2D plane is (NAX+NBX)(NAY+NBY).

[0253] Region A has NAX×NAY pixels

[0254] Region B has NBX×NBY pixels

[0255] A total of (NAX+NBX)(NAY+NBY) pixels = NAX×NAY+NAX×NBY+NAY×NBX+NBX×NBY, new unknown NAX×NBY+NAY×NBX

[0256] For example, the target area A has an X dimension of 20 cm, a Y dimension of 20 cm, and a Z dimension of 20 cm. If the pixel pitch of the x-ray detector is 200 μm, there will be 1000 data points. In other words, there will be 1000 unknown data points to be resolved. Therefore, when the x-rays from the source are scanned in the XY plane parallel to the detector, the x-ray image is sampled by at least 1000 different emission positions. The distance between each adjacent emission position can be selected to produce the minimum number of unknowns and at the same time minimize the sampling time.

[0257] For example, in a 33×33 area, the x-ray emission position is manipulated along the x-axis and y-axis at 1000 first positions, a measurement is acquired at each position, and the distance between adjacent emission positions is the pixel pitch of the detector, which is 200 μm.

[0258] However, when the x-ray emission position is changed to irradiate region A, unknown pixels in region B, the area around region A, are introduced.

[0259] A solution to the above problem is to make the scanning step finer in the second position so that all information in area B can be accurately obtained without further expansion to an even larger area.

[0260] The scanning of the x-ray source or x-ray emission position remains within the scanning region in the first position, except that now the x-ray source is scanned in finer steps that irradiate x-rays over the target region and unknown quantities in region B. For example, the x-rays may be sampled from a previous x-ray emission position by a portion of the moving step size, or a portion of the pixel spacing. If each emission position is different from the previous emission position in the previously described steps, yet at the same time, only the unknown pixels that need to be resolved within region A and region B are irradiated, additional measurements may result in the formulation of new linear equations that reveal new relationships between existing unknown quantities in the target region A or a subset of the unknown quantities in region A in the previously described steps and those unknown quantities newly introduced into region B outside the target region. A system of linear equations can be derived to produce a complete solution as shown in equation (3), where each pixel in the projection path includes a unique set of pixels or voxels in the target region A and some portion outside region A. As Fig.17 As shown in , the newly introduced unknown region will have a depth or measurement in the z-axis, such as p=n 2 , and the total capacity of the new unknown quantities introduced is 4n×n 2 .n 2 is the depth of the target region, measured in motion resolution or motion step size. For example, if there are 100 unknowns along the z-axis in region A, if the x-ray emission position moves within a 10×10 region in the XY plane, the total number of new unknowns introduced is 4×10×100. However, if the x-ray emission position moves within a larger region (e.g., 15×15), the region farthest from the original position will be higher, and as a result, more new unknowns will be introduced, and the total number of unknowns is now 100+4×15=160. 15×15 more than required.

[0261] When the depth is n 2 1000, the xy movement is the square root of 1000, which is approximately 32, the newly introduced unknowns are 4×32=130, and the total unknowns are 1130, or approximately 34, or in order to resolve the 1000 unknowns on the z-axis, ideally the x-ray emission position will be at 1130 different first positions, each position will be separated from its nearest neighbor by a pixel spacing, and the x-ray emission position will be less than 34 or approximately 32 pixel spacings from the original position in the x- and y-directions to minimize imaging time.

[0262] For a finer scanning step, the second point, x-ray emission position can have a different center point than the first position and / or have a portion of the pixel pitch movement increment. And this step can be combined with the previous step by predetermining which area or areas of the XY area the movement increment size is. These areas then have a higher density of x-ray emission position points. In some applications, the order of movement to the first position or the second position is not critical and can be completed in one scan because they can be interleaved in the selected area.

[0263] The present disclosure also provides a method, wherein, independently of the 3D imaging measurement, if the relative spatial position of the target area, or the object relative to the x-ray source changes in any 6D dimension (e.g., by movement or rotation of the target area, or by movement or rotation of the x-ray source), the system can use the movement to resolve the 3D image. Due to the movement in 6D, the elements of the detector will correspond to different projection paths in the target area. During the movement, for each spatial position of the object, the movement can be divided into increments of at least one measurement unit using different x-ray measurements. The geometry of the movement relative to the x-ray source and the detector can be calibrated in space. Each projection path detected by the corresponding detector element or pixel or element area of ​​the detector having two or more pixels can be used as a data point for solving the unknown pixels or voxels on the Z axis of the target area. The unknown quantity newly introduced due to the movement will be determined according to the specific situation.

[0264] Systems in which the x-ray emission location moves in an xy plane parallel to the detector can be combined with the x-ray measurements described above during such movement.

[0265] This type of 3D imaging method is fast and simplified.

[0266] However, when such systems are not available, in one configuration of the present disclosure, multi-dimensional tomography, known to those skilled in the art, is included as part of the present disclosure as an alternative step to the 3D imaging methods described herein to improve otherwise alternative 3D tomography systems based on 2D detectors.

[0267] 2D Imaging

[0268] A multi-dimensional image is generated from 2D images taken from at least two different x-ray emission positions. An exemplary procedure for determining a 2D image using an x-ray machine is provided below.

[0269] The geometry and size of the object or the region of interest in the object may be determined. If such information is predetermined or preset, this step may be skipped.

[0270] The object is then irradiated with x-rays from the first x-ray emission location.The image is then read at the detector assembly.

[0271] Next, the x-ray emission position is moved to a second position in an XY plane parallel to the plane of the detector assembly, wherein the displacement from the first position to the second position is an integer multiple of the detector pixel pitch. When the displacement is one pixel pitch, the projected image of the target area of ​​the object differs from the previous projection image in that the outer edge of the image of the target area is extended on the detector assembly by exactly one row of pixels along the axis of the change in direction. In other words, moving the x-ray source or emission position generates two different projection images for a target area of ​​defined size, and the position of the projection image for the same target area on the detector is extended by only one pixel pitch in the direction of the shift.

[0272] The x-ray emission positioning step and the measurement step are repeated.

[0273] Alternatively, in the 3D imaging process, there are various methods to generate a projection image on the detector, the ultimate goal of which is to minimize new unknown pixels outside the target area in the projection path. For example, the x-ray source emission position can be modified to move in 3D space or in at least one dimension. As long as a certain aspect or part of the imaging process (if not the entire imaging process) uses the method of the present invention, the imaging method of the prior art can be improved. Alternatively, in the case where the object or target area moves, for example, in a conveyor belt or a component is moved in the target area (such as tracking an unknown component in a cavity), the irradiation path of the component is changed, and new unknown pixels are generated in the irradiation path of the component at the same time. Such a single movement may be sufficient to complete a 3D imaging data set. In some cases, in order to complete 3D imaging, it may still be necessary to move the x-ray emission position or the relative position of the x-ray source in order to complete the 3D irradiation and imaging data set. The number of unknown pixels can be increased or changed. However, as long as the irradiation path changes enough to distinguish the complete 3D volume and the newly introduced unknown pixels in the target area, complete 3D imaging can be achieved. The x-ray measurement is repeated with the x-ray source in different positions as needed to produce a 3D image with the desired resolution in the Z-axis.

[0274] Primary X-ray scattering separation

[0275] In this step, for each of the 2D images acquired above, the scatter is separated from the primary x-rays.As mentioned above, a number of different methods of scatter removal or scatter and primary separation are described.

[0276] The present disclosure includes a preferred method of separation of scattered and primary x-rays, wherein multiple x-ray energy sources are used and scattered and primary x-rays are separated at each energy level, and the method and details of material decomposition are found in PCT application PCT / US19 / 14391, which is incorporated herein by reference in its entirety.

[0277] Figure 4-Figure 15 , Figure 8 and Fig. 9 The adjustable beam selector configuration is used in applications where the x-ray emission source or the x-ray emission position is moved out of alignment with the hole in the beam selector to allow primary x-rays to pass through, and the beam selector device is insensitive to the x-ray emission position so that the alignment can be maintained or can be readjusted to align with the x-ray source between 2D x-ray image acquisitions as described above.

[0278] 2D functional imaging

[0279] Although functional imaging is described above as an optional, separate step, it is actually performed as a modification to 2D imaging. Functional imaging provides information in addition to localization or 2D visualization with a single energy x-ray source with or without scatter and primary x-ray separation. Examples of functional imaging methods and systems are described below. Each example is independent of the other examples and can be combined to provide more information as needed for the application.

[0280] Material decomposition and imaging of different materials

[0281] The method can be performed on a 2D image or after a reconstructed multi-dimensional image or a reconstructed 3D image. For example, material decomposition can be performed on a measured projected 2D or a synthesized 2D or multi-dimensional image, or on a dual-level or multi-level or sometimes single-level 3D image.

[0282] Decomposition is the process of using dual-energy or multi-energy x-rays to quantitatively analyze and separate components in an object based on the atomic z and density or other x-ray sensitive properties of the components in the region of interest.

[0283] In one configuration, the x-ray source emits two x-ray pulses from each x-ray source location: a high energy pulse having an average energy level of H, followed by a low energy pulse having an average energy level of L. In another configuration, the x-ray source emits three x-ray pulses from each x-ray source location: a high energy pulse having an average energy level of H, followed by a medium energy pulse having an average energy level of M, and then a low energy pulse having an average energy level of L. In each configuration, each pulse has a single, substantially constant energy spectrum. In another configuration, four or more energy pulses are emitted from the x-ray source.

[0284] In one configuration, the detector assembly employs energy-sensitive photon counting detectors instead of the above-described 2D detectors that cannot distinguish between different energy levels. These detectors can be used with a conventional x-ray source, or with a time-of-flight x-ray source such as a picosecond x-ray source, to collect primary x-rays for densitometry and quantitative analysis and separation of images of different components with varying atomic z. With a conventional x-ray source, energy-sensitive photon counting detectors replace the front detector, the rear detector, or both in a dual detector plus beam selector assembly to ensure primary x-ray and scatter separation while allowing dual-, triple-, or multi-energy and spectral energy imaging and spectroscopy of different materials or components in an object.

[0285] Details of material decomposition using dual or multiple energy sources are found in PCT Application PCT / US19 / 14391, which is incorporated herein in its entirety.

[0286] The present disclosure also provides a method in which single energy x-ray measurement is used for material decomposition. The method may have the following optional elements:

[0287] Multi-dimensional or 3D X-ray imaging of the target area;

[0288] Such images are primary x-ray images with scatter reduced to less than 1%, or in some cases less than 5%, or in some cases less than 10% of the primary signal;

[0289] Determining one or more estimated material properties (e.g., atomic number and density, spatial location), and other properties defined by one of a temporal marker or a structural marker or a fact-defined marker inferred from a digital analysis algorithm performed on data derived from multiple sources in the same or similar object from the same or similar area of ​​interest;

[0290] For systems with multiple measurement units in the region of interest, use the tomographic reconstruction methods described in this disclosure (these estimated material properties can then be modified by reference to stored known material property data);

[0291] Determining the composition of the capacity in the destination region during reconstruction includes partitioning one or more destination regions into components each having a common composition;

[0292] Segmentation can be performed during iterative reconstruction rather than based on voxel properties determined at the completion of iterative reconstruction;

[0293] • One or more further iterations of the tomographic reconstruction algorithm, wherein each iteration updates one or more estimated material properties of the components in the region of interest.

[0294] Functional imaging is improved when primary x-rays and scatter are separated.

[0295] Materials separation and imaging

[0296] Interferometry

[0297] In one configuration, an interferometer with or without scatter removal is employed. Thus, 2D images of absorption, dark field and / or phase contrast images can all be obtained. Such images are used to construct a 3D interferogram.

[0298] The interferometer operates by transmitting x-rays through a phase grating, which introduces interference fringes at a specific distance downstream. When an object is placed in the path of the beam, the object modifies the observed interference pattern via absorption, refraction, and small-angle scattering. Once these signals are read by the detector, the properties of the object and its components can be determined algorithmically. In one example, Talbot-Lau interferometry is used in order to have a large field of view. In Talbot Lau interferometry, a beam splitter grating (G1) is placed in the beam path between the x-ray source (S) and the detector (D). Due to the fractional Talbot effect, the intensity distribution (I) that reveals the periodic structure of the beam splitter grating appears at a certain distance behind the grating. If an object (O) is placed in front of the beam splitter grating, the intensity distribution changes due to the absorption, scattering, and refraction properties of the object. The fractional Talbot effect requires spatially coherent radiation. To meet this requirement, a microfocus x-ray tube with a sufficiently small focus can be used. Alternatively, a slit mask (G0) can be placed in front of the focus of a conventional x-ray tube. The mask absorbs certain parts of the x-ray beam, thereby producing spatially coherent slit sources. Each of these slit sources produces a self-image of the beam splitter grating. By exploiting the Lau effect, it is ensured that these self-images are superimposed on a sharp intensity distribution. Normally, these interference fringes are too small to be resolved by conventional x-ray detectors. To overcome this challenge, an absorbing analyzer grating (G2) with the same period as the interference fringes is placed in the plane of these fringes. The analyzer grating is used to sample the periodic intensity distribution by moving it stepwise in a plane perpendicular to its grating bars.

[0299] For example, to produce a coherent x-ray beam, the interferometer uses a pixelated x-ray source or a coherent source grating. In another example, the interferometer has a MEMs-based, crystal-based diffraction grating, or employs an acoustically modulated crystal grating.

[0300] 3D Imaging

[0301] High-resolution 3D imaging of an object with defined dimensions has the following steps.

[0302] Calibration is as described above.

[0303] Primary x-ray and scatter separation and / or functional imaging. Examples are described in US Provisional Patent Application Nos. 62 / 620,158, 62 / 628,370 and 62 / 628,351, as explained above, are dual energy and multi-energy imaging.

[0304] The x-ray emission position is shifted relative to the object to a second position in the x-ray plane parallel to the detector plane. The shift distance between the x-ray emission positions is set by extending the outer edge of the detected image along the target area by one line of pixels on the detector and along the axis of the shift direction so that each subsequent image contains a different projection image of the target area than the previous image. The x-ray measurement is repeated for each x-ray emission position. The positions can also be shifted by less than one line of pixels, or by more than one line of pixels.

[0305] Determine the geometry or size of the target area in the object. If such information is predetermined and stored in the computing device, skip this step.

[0306] Based on the thickness in the z-axis perpendicular to the x-ray plane, determine the total number of pixel-wide x-ray emission locations P required to produce a complete 3D image, where P = thickness / pixel pitch (or required resolution in the z-axis) = n 2 +4n. If this information is predetermined, skip this step.

[0307] Repeatedly move the x-ray emission position to the first position and perform at least P x-ray measurements on the XY plane so that the travel area of ​​the emission position is limited by the x-axis or y-axis coordinate: less than or equal to √(n 2 +4n). In the case where 4n is small enough compared to P, the p-4n first position is sufficient for 3D imaging reconstruction. To resolve the unknown quantity introduced in the new x-ray emission position, the second position is scanned. This is when the x-ray emission position is closer in distance to the adjacent second position than the adjacent first position, but travels in the same area as the first position.

[0308] Note that for x-rays with a pixelated x-ray source, rather than moving the x-ray source or physically moving the x-ray emission location, a different pixel is used as the x-ray source each time an image is taken.

[0309] Combining the x-ray measurements described above, the linear system of equations m×n×p is solved and determined for the unknown pixels on the Z axis of the region of interest. New unknown pixels created from all x-ray emission positions except the first position are solved and determined.

[0310] The computing device uses conventional computed tomography imaging algorithms, including simply interpolating resolved unknown pixel values ​​to derive a 3D image of the region of interest based on the previous steps. The computing device provides a multi-axis representation at various resolutions of the 2D image, which is combined with a multi-dimensional representation of both the region of interest in the object.

[0311] The x-ray emission position can be moved in a planar space of less than 5mm×5mm, 4mm×4mm, 3mm×3mm, 2mm×2mm or 1mm×1mm to obtain a full 3D image with a resolution of 100μm for a 20cm×20cm×20cm chest image. This allows a significant increase in measurement speed and a significant decrease in the amount of radiation required to obtain 3D images. As a result, patient safety and comfort are significantly increased.

[0312] The present disclosure includes embodiments where for x-ray measurements of a 20cm x 20cm x 20cm object, less than 1150 images or in some cases 1000 images are used at 100μm resolution to get a complete 3D image, in some cases the scatter is <10% or 5% or 1% of the primary x-ray signal. For higher resolutions such as 100nm or 10nm, the number of x-rays measured will increase proportionally, e.g., 1 million images. However, for a 10mm x 10mm x 10mm sample, at 100nm resolution, there will be 100,000 measurements or 30μm x 30μm movement of the x-ray emission position in the XY plane to get a complete 3D image.

[0313] Another aspect of the present disclosure is to image large objects (25cm x 25cm x 25cm) with small movements in the x and y directions (e.g., 5mm or sometimes even less, such as 1mm), achieving relative movement of x-ray emission positions with the object in a two-dimensional plane, wherein the resolution or distance between adjacent x-ray emission positions is within 100μm or 0.1μm, depending on the desired resolution and achievable resolution defined by the pixel pitch of the detector hardware. The farthest x-ray emission position from the home position can be less than 5 degrees, or 4 degrees or 2 degrees, or less than 1.5 degrees, in order to obtain complete 3D imaging with a minimum number of 2d images. For lower resolution measurements (e.g., 500μm) of an object with a thickness or depth of 25cm, the farthest x-ray emission position can be 7.5cm from the home position, and the number of images taken is significantly reduced compared to measurements with higher resolutions (e.g., 100μm or 0.1μm) to complete 3D image reconstruction.

[0314] The present disclosure allows for measurements in the sub-nanometer range (e.g., 0.01 nm or 0.1 nm) and thereby enables the construction of a 3D image of an object. For example, for an object with a size of 10 μm×10 μm×10 μm (10 μm is thickness), using an x-ray microscope, the resolution can be in the sub-nanometer range. Fig.31 As shown in (35), the x-ray microscope can have a condenser lens m-1, an aperture m-2, an objective lens m-4 and an x-ray detector assembly m-5. M-5 can be, for example, an x-ray detector or a photodiode array or a photon counter, a spectrometer including an energy dispersive x-ray optical device (such as a grating), and / or a spatially sensitive detector. In some cases, a scintillator that converts the x-ray signal into optical light can use the following measurement signals: a camera sensor, a photon sensitive camera or a PMT or PMT array, or the object can be placed immediately after the aperture. The x-rays emitted from the undulator as an insertion device in the electron (or positron) storage ring are monochromatized m-7 and focused onto the sample m-3 by the condenser m-1, which can be a wave zone plate, whereby the objective lens amplifies the signal onto the detector m-5. The sample is raster scanned and the transmitted intensity is monitored by the x-ray sensitive detector m-5. The distance between the nearest x-ray emission positions can be as small as 0.01nm to 100nm, depending on the application requirements. The condenser lens m-1 can also be a specialized X-ray optical device called a multi-layer Laue lens (MLL), which is two vertically oriented lenses. These lenses consist of alternating layers of two different materials with nanometer thickness.

[0315] With MLL, the resolution of x-ray microscopy can reach 1 nm. In practice, in the case of the present disclosure, the limitation of x-ray microscopy is the x-ray focusing optics, which theoretically enables the resolution along the z-axis to be diffraction limited by the x-ray wavelength. However, the limitation of the present invention is the x-ray optics used to focus the x-rays into a spot as small as 0.01 nm.

[0316] The collimator can be used to select the radiation area to reduce the radiation on the object. Alternatively, the anode target can be modulated and rotated so that an area on the anode target can be selected for x-ray generation. In another configuration, the electron beam emission source can be modified to selectively activate the electron emission unit to generate x-ray radiation only in the selected area. For example, in an x-ray source based on a field emitter, only selected areas of the field emitter are activated. For example, if 200 elements of field emitter material (such as nanotubes or nanowires) are required to generate enough electron current to generate the x-rays required for the application, one or more field emitter elements (such as nanotubes or nanowires) can form a field emission unit, which can also include a computing device and can be activated independently of each other. For example, each field emission unit can have a similar number of field emission elements, as shown in C7 in Figure 24. However, in other configurations, each field emission area can have a different number of field emission elements from the remaining field emission elements.

[0317] The mechanism for activating each field emission unit can be the same or similar to those known to those skilled in the art. The computer processor will dictate which region to activate at what time. Another part of the disclosure is multiple activation of two or more independent field emission regions at different times.

[0318] Multi-dimensional or 3D images

[0319] Another aspect of the present disclosure is to include two or more x-ray emission positions or two or more x-ray sources for multi-dimensional imaging of two or more objects in a target area using a 3D imaging method as described above. Each x-ray source or emission position irradiates a different path in the target area on its corresponding object. Such imaging can be synchronized. Multi-dimensional imaging of a selected area can be performed simultaneously using different x-ray sources or x-ray emission positions, but not synchronized with each other. This means that each x-ray emission position can be moved to irradiate a different projection path on its designated object, or different x-ray emission positions in a predetermined emission position are opened for subsequent irradiation. The result is to obtain separate 2D images from different objects in the target area at the same time, synchronously or asynchronously, or at different times required by the application.

[0320] Alternatively to the above-described multidimensional x-ray imaging measurement and reconstruction process, another embodiment of 3D image acquisition and generation is based on scanned beam digital x-ray (SBDX). SBDX uses an electromagnetically scanned electron beam incident on a large area transmission type tungsten target. The electron beam is raster scanned every 1 / 15 second on a 2D array of source focal spot positions. A multi-aperture collimator defines a series of narrow overlapping x-ray beams that converge on a 2D detector. The geometric relationship between the narrow beam projections is limited by the precise and rigid geometry of the SBDX collimator and the fixed detector position. The typical SBDX system geometry is as follows: source-detector-distance (SDD) = 1500 mm; source-axis-distance (SAD) = 450 mm; focal position = 71×71; focal spacing = 2.3×2.3 mm; local detector array = 320×160; local detector element spacing = 0.33 mm; and detector statistical stack mode (Detector bin mode) = 2×2.

[0321] SBDX has inherent tomosynthesis capability due to the use of inverse geometry beam scanning. A real-time GPU-based image reconstructor is used to produce real-time displays similar to conventional fluoroscopy. Each displayed 2D image frame is generated by a two-stage reconstruction procedure. First, a shift and add digital tomosynthesis is performed to produce a stack of, for example, 32 single-plane images with, for example, 5 mm plane spacing. The pixel centers for the stack of tomosynthesis images are defined so that a fixed pixel position in the stack (e.g., row 100, column 100) corresponds to an x-ray originating from the center of the detector. Next, a gradient filtering procedure is applied to each single-plane image to identify local areas of high clarity and contrast. The final 2D "synthetic" image is then formed by selecting a pixel value from the single-plane image with the highest contrast and clarity for each pixel position. Due to the geometry of the tomosynthesis pixel centers and the synthesis procedure, the final synthetic image can be viewed as an inverse "virtual" cone-beam projection of the focused object in the object volume. The virtual SBDX projection originates from the center of the detector and falls on the source plane. The spacing of the virtual detector elements at the source plane is, for example, 0.23 mm based on the assumed geometry.

[0322] Alternatively, various 3D computed tomography configurations and methods may be utilized. These may include, for example, using a motorized x-ray source to span large angles, linearly moving a pixelated x-ray source in 1D, 2D, 3D, or in 6D space, or using methods for 3D reconstruction different from those described above. These may be combined with primary x-ray and scatter separation methods similar to those described above, with derived primary x-ray and scatter separation methods described above, or with the same primary x-ray and scatter separation methods described above to achieve the desired resolution and quantification of x-ray tomography by separating scatter and primary x-rays such that scatter is <10% or <5% or <1% of the primary x-ray signal.

[0323] In systems involving multi-dimensional x-ray imaging methods, when the scatter is small compared to the primary x-rays (such as in low-scattering samples or small animals), a multi-dimensional image can be constructed without involving primary x-rays and scatter separation steps.

[0324] One aspect of the present disclosure is an embodiment comprising a method comprising the steps of:

[0325] As described above, a low resolution 3D or 2D image is derived using more than one pixel or pixel region as a unit of unknown voxel. Based on the one or more images derived above, an object region is selected to be imaged at a higher resolution (e.g., a resolution as high as a single pixel). Higher resolution can also be applied to methods in which a visible light, optical detector is used downstream of an x-ray scintillator to convert x-rays into visible light and captured by a visible light, optical detector or a visible light photodiode or photodiode array. In this case, the pixel size resolution can be the resolution of the camera or visible light detector or photodiode.

[0326] A high-resolution image can be obtained as described above, and a low-resolution image of an object can be obtained using the above method to track the object. The low resolution can be defined by a measurement unit of two or several pixels instead of a measurement unit of one pixel. For example, for a 20 cm thick object, at a 5 pixel resolution, and a pixel pitch of 100 μm for each pixel, each measurement unit is 5×100 μm=500 μm. There are 20 cm / 500 μm=400 unknown units or 400 positions that need to be resolved. Therefore, there are only 20 units×20 units of x-ray emission positions, or an area of ​​<4 mm×4 mm, where the x-ray emission positions need to be scanned in the XY plane.

[0327] Medical applications include, but are not limited to: detecting cardiovascular abnormalities, detecting fractures and other musculoskeletal injuries, helping diagnose neurological diseases, dental, cancer screening, diagnosing chest complications and conditions, surgical and procedural guidance and biopsy guidance, and treatment management and monitoring. Industrial applications include, but are not limited to, x-ray inspection and identification, safety and environmental issues.

[0328] One aspect of the present disclosure is to include the following methods based on existing hardware configurations, since the present disclosure enables the detection of temporal markers and dynamic events in 2D and multi-dimensional and 3D at milliseconds or faster:

[0329] Time: Time-stamp each captured image (whether 2D, 3D or multi-dimensional), such as concatenating DICOM tags or adding time tags.

[0330] Fluid dynamics, flow direction, dynamic movement in 6D: by using contrast agents, such as x-ray measurements of sensitive markers, nanoparticle-labeled markers, or microbubbles administered in one or more phases. Administration can be, for example, oral ingestion or by injection or inhalation, or methods known to those familiar with in vivo contrast agent ingestion methods. The method is used to track, for example, blood flow, fluid flow in microfluidics on a chip or in a laboratory, tracking of components such as implants or surgical tools or biopsy probes, or disease markers in a body region. 3D images or multi-dimensional images or gated x-ray measurements are taken at discrete times during one or more time intervals of interest, and markers can be located by multi-dimensional imaging or 2D imaging or using spectral or multi-energy x-ray decomposition at the area of ​​interest. This is useful when the component to be tracked consists of one or more regions that can be distinguished from the background in the x-ray measurement, for example, when such regions on the component are at atomic z that are significantly different from those materials in its background.

[0331] Co-localization with other measurement modalities (e.g., spectroscopy, endoscopy, optical tomography, ultrasound, electrophysiology, MRI or SPECT, or PET or other x-ray based measurements) by identifying and / or locating one or more contrast agents shared by the x-ray and modality, one or more spatial markers or structural markers, or the localization of one or more substances in time or space or in space. In some configurations, such devices have intracavitary probes (e.g., catheters and guide wires). The x-ray imaging of the present disclosure provides methods for identifying and guiding the location of such probes and devices by using material decomposition methods or by using probes with one or more regions designed to be visible at specified x-ray energy levels. In the case of using different chemical or molecular markers, in the case of x-ray markers or contrast agents that are different from those used for other modalities, x-ray contrast agents can be combined with contrast agents used for other modalities, or x-ray contrast agents can be spatially associated with contrast agents for other modalities.

[0332] · Using chemical-based intubation (such as drugs) or energy perturbations (such as ultrasound or electromagnetic waves, such as lasers or radio frequency devices, such as in RF ablation of tissues such as the heart or kidneys), or ultrasonic perturbations of changes in capillaries or other tissues, 3D imaging and x-ray analysis of components within the target area, changes in tissue composition in the ablated or affected area can give different x-ray measurements during energy perturbations. Optical probes or ultrasonic probe devices or catheters that deliver energy (such as RF) can be used. For example, the probe can have areas with different material composition than the background, which results in different x-ray measurements. In addition, using 2D functional imaging and / or 3D functional imaging methods, including material decomposition methods, such changes can be identified and located. A database of markers associated with changes can be established in advance at each perturbation stage for reference and lookup to help diagnose and identify the perturbation stage.

[0333] Identification of an image or set of images: for example, labeling each image with at least a name and / or description of an object or area of ​​interest, or at least a unique identification number or a binary identification number, or all of the above id information.

[0334] Recording the number of images of each subject taken based on the DICOM tag or unique identifier for each imaging procedure or each imaging session or each study or treatment or diagnosis or monitoring or treatment plan, or research project or tracking period.

[0335] · Records and statistics on the number of images taken and processed for each x-ray system (including the computer, x-ray hardware and software); a memory storage unit that electronically stores one or more files, each file having a report or updated record of the number of images taken during a time frame such as a day or month or year or since the system was used; the reports or files can be accessed by physical access to the computer and its associated x-ray imaging system or electronic memory storage unit remotely via the Internet or an intranet or direct physical access (such as a memory stick or security key capable of storing and processing digital information); the computer is programmed to generate reports based on the files, electronically store, and periodically send the reports automatically to the intended recipients via email or hard copy or other electronic means (such as stored on a server, password protected, accessible to the intended recipients), which can be accessed by the intended recipients, who can access the records by logging into the system using a password at the x-ray system location or at a remote location.

[0336] The above describes minimizing spatial variations between each adjacent image acquired and the total deviation from the original imaging position, minimizing imaging acquisition time, minimizing radiation and complexity, radiographic imaging-based CT (3MR-CT), its variants, the spectral or multi-energy version is described as 3MR-SPECTRAL CT and its variants, the functional imaging version is described as 3MR-F-CT.

[0337] Thus, a 3D imaging method has been shown and described.Since certain changes may be made in the present disclosure without departing from the scope of the disclosure, it is intended that all matter described in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative and not limiting.

Claims

1. An x-ray measuring device capable of determining a three-dimensional x-ray image of a target area in an object, the x-ray measuring device comprising: an x-ray source configured to emit x-ray radiation at the target region, wherein a plurality of projection images are acquired using x-ray radiation emitted from a plurality of different x-ray emission positions relative to the object, the plurality of different x-ray emission positions being separated from their adjacent x-ray emission positions by a distance approximately equal to a resolution along the axis; an x-ray detector comprising a plurality of detector elements arranged in a two-dimensional plane perpendicular to the axis opposite the x-ray source, the x-ray detector configured to detect x-ray radiation after attenuation of the x-ray radiation by a region of interest of the object and to provide an indication of the detected x-rays; as well as A processor is configured to receive an indication of the detected x-rays and to reconstruct the detected x-ray radiation into a three-dimensional image of the region of interest.

2. An x-ray measurement device according to claim 1, wherein the relative spatial position of the x-ray source and / or the x-ray emission position and / or the x-ray radiation moves relative to the object, and the x-ray source and / or the x-ray emission position and / or the x-ray radiation are configured to move less than one pixel pitch and / or the distance between the nearest adjacent x-ray sources between two consecutive measurements.

3. The X-ray measuring device according to any one of the preceding claims, wherein: The x-ray source and / or the x-ray emission position and / or the x-ray radiation are configured to move by one pixel pitch between two consecutive measurements.

4. The x-ray measurement apparatus of claim 1, wherein the x-ray source and / or the x-ray emission position and / or the x-ray radiation are configured to move by less than 1 pixel pitch to up to 10 pixel pitches between two consecutive measurements.

5. The X-ray measuring device according to claim 1, wherein: The processor is configured to resolve the detected x-ray radiation into a three-dimensional image by solving a system of linear equations.

6. The X-ray measuring device according to claim 5, wherein: The system of linear equations resolves a plurality of unknown voxels along an axis indicated by the depth of the object and / or on a z-axis perpendicular to the detector.

7. The X-ray measuring device according to claim 1, wherein: The hardware is configured to measure, calculate and / or remove scattered x-rays.

8. The X-ray measuring device according to claim 1, wherein: The processor is configured to measure, calculate and / or remove scattered x-rays.

9. The X-ray measuring device according to claim 1, wherein: The x-ray measurement device resolves a three-dimensional space indicating a three-dimensional portion of the region of interest in an object, wherein the three-dimensional space has unknown pixels or voxels in three dimensions.

10. The X-ray measurement apparatus according to claim 9, wherein the three-dimensional space is based on a unit of voxel or pixel.

11. The X-ray measuring device according to claim 7, wherein: The scattering is ignored.

12. The X-ray measuring device according to claim 7, wherein: The scatter is measured, calculated and / or removed in a time domain analysis using short pulse duration x-ray bursts.

13. The x-ray measurement device of claim 12, wherein the short pulse duration does not exceed picoseconds.

14. The X-ray measuring device according to claim 7, wherein: Frequency domain analysis is used to measure, calculate and / or remove the scatter.

15. The x-ray measurement device of claim 7, wherein an attenuation blocker is used to measure, calculate and / or remove the scatter.

16. The x-ray measuring device according to claim 7, wherein: Phase retarders and / or diffraction grating beam splitters are used to measure, calculate and / or remove the scatter.

17. The x-ray measuring device according to claim 7, wherein: The scatter is measured, calculated and / or removed using interferometry.

18. The x-ray measuring device according to claim 7, wherein: Grating or beam splitting is used to measure, calculate and / or remove the scatter.

19. The x-ray measurement apparatus of claim 7, wherein the scatter is measured, calculated and / or removed using a beam splitting detector.

20. The x-ray measurement device according to claim 7, wherein: The scatter is measured, calculated and / or removed using a beam selector.

21. The x-ray measurement device according to claim 1, wherein: The x-ray source emits pulsed or continuous x-rays.

22. The x-ray measurement device according to claim 1, wherein: The x-ray source is an x-ray tube, a cold cathode x-ray source, a metal liquid jet, a laser Compton x-ray, a synchrotron or synchrotron-like x-ray source, a linear accelerator-based source, a coherent or partially coherent x-ray source and / or a field emission nanotube or a monochromatic source.

23. The x-ray measurement device according to claim 1, wherein: The x-ray source emits x-ray radiation at two different energy levels.

24. The x-ray measurement device according to claim 1, wherein: The x-ray source emits x-ray radiation at three or more different energy levels.

25. The x-ray measurement device according to claim 1, wherein: The x-ray source moves in a plane parallel to the x-ray detector.

26. The x-ray measurement device according to claim 1, wherein: The x-ray source is immovable and the test material is moved in a predetermined amount.

27. The x-ray measurement device according to claim 1, wherein: The x-ray source is immovable, and the detector and the object are moveable by a known amount.

28. The x-ray measurement device according to claim 1, wherein the x-ray source is a metal, graphene, silicon based cold cathode and / or a field emitter based on carbon field emitter nanostructures.

29. The x-ray measurement device according to claim 1, wherein: The x-ray source is configured to be moved by applying an electric field or a magnetic field.

30. The x-ray measurement device of claim 1, further comprising an electromagnetic lens.

31. The x-ray measurement apparatus of claim 1, further comprising a two-dimensional actuator configured to physically move the x-ray source.

32. The x-ray measurement apparatus of claim 1, further comprising a two-dimensional actuator that physically rotates the x-ray source.

33. The x-ray measurement device according to claim 1, wherein: Total internal reflection and / or polycapillaries are used to move the x-ray radiation.

34. The x-ray measurement device according to claim 1, wherein: Charged plates and / or electrostatic lenses are used to move the electrons that produce the x-ray radiation.

35. The x-ray measurement device according to claim 1, wherein: Magnetic plates are used to move the electrons that produce the x-ray radiation.

36. The x-ray measurement device of claim 1, wherein: Electro-optic lenses are used to move the electrons that produce the x-ray radiation.

37. The x-ray measurement device according to claim 1, wherein: Electromagnetic coils are used to move the electrons that produce the x-ray radiation.

38. The x-ray measurement device of claim 1, wherein: The x-ray source uses a relativistic electron beam with current modulation.

39. The x-ray measurement device according to claim 1, wherein: The x-ray source is a crystal interferometer.

40. The x-ray measurement device according to claim 10, wherein: The x-ray emission position is n 2 The area of ​​the light spot n 2 to obtain a depth resolution n along the target area. 2 The image data required for each unknown pixel is measured in units of the size of the detector's pixel pitch or achievable resolution.

41. The x-ray measurement device according to claim 1, wherein: The processor is also configured to determine a preliminary geometric relationship between the x-ray source and the x-ray detector.

42. The x-ray measurement device according to claim 41, wherein A test x-ray shot is used to determine the preliminary geometric relationship.

43. The x-ray measurement device of claim 1, wherein: The plurality of detector elements are arranged in the two-dimensional plane in a matrix form.

44. The x-ray measurement device of claim 1, wherein: The x-ray source and / or the x-ray emission position and / or the x-ray radiation are configured to move in distance increments, the distance increments being defined by a resolution.

45. The x-ray measurement device of claim 1, wherein: The x-ray radiation is emitted in a cone beam.

46. ​​The x-ray measurement device of claim 1, wherein: The x-ray radiation is emitted in a fan beam.

47. The x-ray measurement device of claim 1, wherein: The x-ray radiation is emitted in a fan beam.

48. The x-ray measurement apparatus of claim 2, further comprising limiting the x-ray source and / or the x-ray emission location and / or the total travel area of ​​the x-ray radiation to a number of unknown pixels introduced by the movement and / or a distance proportional to the depth of the object.

49. The x-ray measurement apparatus of claim 1, further comprising limiting the x-ray source and / or the x-ray emission location and / or the total travel area of ​​the x-ray radiation to the same distance as the depth of the object.

50. The x-ray measurement device of claim 1 further comprising movement in a two step process: a first position and a second position, wherein the first position is an increment of the required resolution or pixel pitch over distance, and the second positions are in the same travel area and are less incrementally spaced from each other than the first position.

51. The x-ray measurement device of claim 1, wherein: The x-ray radiation and / or the x-ray source and / or the relative position of the x-ray source are configured to move during a step comprising a first position and a second position.

52. An x-ray measurement apparatus according to claim 51, wherein the distance moved to the first position is an increment of resolution and / or pixel pitch.

53. The x-ray measurement device according to any one of claims 51-52, wherein: The incremental distance moved from the first position to the second position is smaller than the incremental distance moved to the first position.

54. The x-ray measurement device according to any one of claims 51-52, wherein: The first position and the second position are on the same, similar, or substantially similar path of travel and are staggered at one or more selected areas.

55. The x-ray measurement device of claim 1, further comprising a dwell time at each position of 0.01 ms to 10 ms.

56. The x-ray measurement device of claim 1, wherein: The distance between the emission positions on the two-dimensional plane is in the range of 0.1 μm to 100 μm.

57. The x-ray measurement device of claim 1, wherein: The distance between emission positions on the two-dimensional plane is 0.01 nm to 0.1 μm.

58. The x-ray measurement device of claim 1, wherein: The angle between the x-ray source emission position and the primary x-ray source emission position is less than 2 degrees.

59. The x-ray measurement device of claim 58, wherein: The angle between the x-ray source emission position and the primary x-ray source emission position is less than 7.5 degrees.

60. The x-ray measurement device according to claim 7, wherein: The x-ray radiation is emitted in a cone beam and the scatter is removed to less than 1% of the primary.

61. The x-ray measurement device of claim 60, wherein: The x-ray radiation is emitted in a cone beam and the scatter is removed to less than 5% of the primary.

62. The x-ray measurement device of claim 60, wherein: The x-ray radiation is emitted in a cone beam and scattered x-rays are removed to less than 10% of the primary.

63. The x-ray measurement device of claim 20, wherein: The beam selector is a multi-plate system wherein the apertures on the multi-plate system have progressively increasing sizes away from the x-ray source.

64. The x-ray measurement device of claim 1, wherein: A calibration step in which x-ray measurements are made is performed at the x-ray source and / or the emission position and / or the x-ray irradiation position in which images of the object are taken for 3D image reconstruction without an object.

65. The x-ray measurement apparatus of claim 1, further comprising a system for removing scatter from an x-ray imaging system.

Images