Imaging system for recording different types of images and corresponding operating method

Abstract

A system comprising: an X-ray detector; m cameras (camera (i), i = 1,..., M), where M is a positive integer; and a sample stage including a window that is non-transparent to the X-rays. The X-ray detector is configured to take an X-ray absorption image of a sample located on the window of the sample stage. For each value of i, the camera (i) is configured to take an image (i) of the sample. For each value of i, substantially all photons from the sample and detected by the camera (i) resulting in the image (i) belong to a wavelength range (i). The wavelength range of the X-rays and the wavelength range (i) do not overlap, i = 1,..., M.

Description

Background Art

[0001] A radiation detector is a device that measures properties of radiation. Examples of these properties may include the spatial distribution of the radiation's intensity, phase, and polarization. The radiation measured by a radiation detector may be radiation that has passed through an object. The radiation measured by a radiation detector may be electromagnetic radiation, such as infrared light, visible light, ultraviolet light, X-rays, or gamma rays. Radiation may also be of other types, such as alpha and beta rays. An imaging system may include one or more radiation detectors. Summary of the Invention

[0002] Disclosed herein is a system comprising: an X-ray detector; M cameras (camera (i), i = 1, ..., M), where M is a positive integer; and a sample stage comprising a window that is not non-transparent to X-rays. The X-ray detector is configured to capture an X-ray absorption image of a sample positioned on the window of the sample stage. For each value of i, the camera (i) is configured to capture an image (i) of the sample. For each value of i, substantially all photons originating from the sample and detected by the camera (i) to generate the image (i) belong to a wavelength range (i). There is no overlap between the wavelength range of the X-rays and the wavelength range (i), i = 1, ..., M.

[0003] In one aspect, the system further comprises a mask comprising N parallel slits, the N slits being configured to form N X-ray fan beams, respectively, from the N slits, where N is a positive integer. The mask is configured to translate in a direction perpendicular to the N slits so that the N X-ray fan beams and the X-ray detector scan the entire sample.

[0004] In one aspect, M = 1, the wavelength range (1) is visible light.

[0005] In one aspect, M = 1, and the wavelength range (1) is infrared light.

[0006] In one aspect, M = 2, the wavelength range (1) is visible light, and the wavelength range (2) is infrared light.

[0007] In one aspect, M > 2.

[0008] In one aspect, the X-ray detector is configured to move between two separate positions, respectively close to and far away from the sample; the X-ray detector is configured to capture two X-ray images of the sample from the two positions, respectively; and the system is configured to generate an X-ray phase contrast image of the sample based on the two X-ray images.

[0009] In one aspect, the system further comprises a processor configured to generate a composite image of the sample by superimposing at least the X-ray absorption image and the image (i), i=1, . . . , M.

[0010] In one aspect, the system further comprises a plate that presses the sample against the window of the sample stage such that the sample has a uniform thickness measured perpendicular to a support surface of the window. The plate is not non-transparent to X-rays and photons of the wavelength range (i), where i = 1, ..., M.

[0011] In one aspect, the system further comprises an X-ray source for capturing the X-ray absorption image.No X-ray photons from the X-ray source strike any of the M cameras.

[0012] In one aspect, the sample stage is located between the X-ray detector and the M cameras.

[0013] In one aspect, the system further comprises an X-ray source for capturing the X-ray absorption image, wherein the X-ray source and the M cameras are within a right circular cone having a vertex located on the sample and an opening angle of a maximum of 10 degrees, a maximum of 20 degrees, a maximum of 30 degrees, or a maximum of 40 degrees.

[0014] In one aspect, the axis of the right circular cone is perpendicular to the best fit plane of all sensing elements of the X-ray detector.

[0015] In one aspect, the sample comprises human or animal tissue.

[0016] This document also discloses a method for using the system. The method includes: capturing the X-ray absorption image of the sample using the X-ray detector; capturing the image (i) of the sample using the M cameras, where i = 1, ..., M; and generating a composite image of the sample by superimposing at least the X-ray absorption image and the image (i), where i = 1, ..., M.

[0017] In one aspect, the system further comprises a mask comprising N parallel slits, wherein N is a positive integer, and the method further comprises forming N X-ray fan beams from the N slits, respectively, and translating the mask in a direction perpendicular to the N slits, thereby scanning the entire sample using the N X-ray fan beams and the X-ray detector.

[0018] In one aspect, the method further includes: capturing two X-ray images of the sample using the X-ray detector from two separate positions, one close to the sample and the other far away from the sample; and generating an X-ray phase contrast image of the sample based on the two X-ray images. Generating the composite image includes superimposing the X-ray absorption image, the image (i), and the X-ray phase contrast image, where i = 1, ..., M. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A radiation detector according to an embodiment is schematically illustrated.

[0020] Figure 2 A simplified cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0021] Figure 3 A detailed cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0022] Figure 4 A detailed cross-sectional view of a radiation detector according to an alternative embodiment is schematically shown.

[0023] Figure 5 An imaging system according to an embodiment is schematically illustrated.

[0024] Figure 6 A flow chart outlining the operation of an imaging system according to an embodiment is shown. DETAILED DESCRIPTION

[0025] Radiation detectors

[0026] Figure 1 A radiation detector 100 is schematically shown as an example. The radiation detector 100 may include an array of pixels 150 (also referred to as sensing elements 150). The array may be a rectangular array (e.g., Figure 1 as shown), a honeycomb array, a hexagonal array, or any other suitable array. Figure 1 The array of pixels 150 in the example of FIG. 5 has 4 rows and 7 columns; however, in general, the array of pixels 150 may have any number of rows and any number of columns.

[0027] Each pixel 150 can be configured to detect radiation from a radiation source (not shown) incident thereon, and can be configured to measure characteristics of the radiation (e.g., energy, wavelength, and frequency of the particles). Radiation can include radiation particles such as photons (X-rays, gamma rays, etc.) and subatomic particles (alpha particles, beta particles, etc.). Each pixel 150 can be configured to count the number of radiation particles incident thereon and whose energies fall into multiple energy bins over a period of time. All pixels 150 can be configured to count the number of radiation particles incident thereon and located in multiple energy bins over the same period of time. When the incident radiation particles have similar energies, the pixel 150 can be configured only to count the number of radiation particles incident thereon over a period of time, without measuring the energy of individual radiation particles.

[0028] Each pixel 150 can have its own analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident radiation particle into a digital signal, or to digitize an analog signal representing the total energy of multiple incident radiation particles into a digital signal. Pixels 150 can be configured to operate in parallel. For example, while one pixel 150 is measuring an incident radiation particle, another pixel 150 may be waiting for a radiation particle to arrive. Pixels 150 do not necessarily need to be individually addressable.

[0029] The radiation detector 100 described herein may have applications such as X-ray telescopes, X-ray mammography, industrial X-ray defect detection, X-ray microimaging or microradiography, X-ray casting inspection, X-ray non-destructive testing, X-ray weld inspection, X-ray digital subtraction angiography, etc. It may be appropriate to use the radiation detector 100 in place of photographic plates, photographic films, photostimulated phosphor plates (PSP plates), X-ray image intensifiers, scintillators, or other semiconductor X-ray detectors.

[0030] Figure 2 Schematically shows a Figure 1 A simplified cross-sectional view of radiation detector 100 taken along line 2-2 is shown. Specifically, radiation detector 100 may include a radiation absorbing layer 110 and an electronic circuit layer 120 (which may include one or more ASICs or application-specific integrated circuits) for processing and analyzing electrical signals generated in radiation absorbing layer 110 by incident radiation. Radiation detector 100 may or may not include a scintillator (not shown). Radiation absorbing layer 110 may include a semiconductor material such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest.

[0031] As an example, Figure 3 Schematically shown Figure 1 Detailed cross-sectional view of the radiation detector 100 along line 2-2. Specifically, the radiation absorbing layer 110 may include one or more diodes (e.g., pin or pn) formed by one or more discrete regions 114 of a first doping region 111, a second doping region 113. The second doping region 113 may be separated from the first doping region 111 by an optional intrinsic region 112. The discrete regions 114 may be separated from each other by the first doping region 111 or the intrinsic region 112. The first doping region 111 and the second doping region 113 may have opposite types of doping (e.g., the first doping region 111 is p-type and the second doping region 113 is n-type, or the first doping region 111 is n-type and the second doping region 113 is p-type). Figure 3 In the example of , each discrete region 114 of the second doped region 113 forms a diode with the first doped region 111 and the optional intrinsic region 112. Figure 3 In the example, the radiation absorbing layer 110 has a plurality of diodes (more specifically, 7 diodes corresponding to Figure 1 The array has 7 pixels in one row 150, for simplicity, Figure 3 Only two pixels 150 are marked in FIG. Multiple diodes may have electrode 119A as a common electrode. The first doped region 111 may also have multiple discrete portions.

[0032] The electronic circuit layer 120 may include an electronic system 121 suitable for processing or interpreting signals generated by radiation incident on the radiation absorbing layer 110. The electronic system 121 may include analog circuits such as filtering networks, amplifiers, integrators, and comparators, or digital circuits such as a microprocessor and memory. The electronic system 121 may include one or more ADCs (analog-to-digital converters). The electronic system 121 may include components shared by multiple pixels 150 or components specific to a single pixel 150. For example, the electronic system 121 may include an amplifier specific to each pixel 150 and a microprocessor shared across all pixels 150. The electronic system 121 may be electrically connected to the pixels 150 via interconnect channels 131. The spaces between the interconnect channels may be filled with a filler material 130, which may increase the mechanical stability of the connection between the electronic circuit layer 120 and the radiation absorbing layer 110. Other bonding techniques may allow the electronic system 121 to be connected to the pixels 150 without the use of interconnect channels 131.

[0033] When radiation from a radiation source (not shown) strikes the radiation absorbing layer 110, which includes a diode, the radiation particles may be absorbed and generate one or more charge carriers (e.g., electrons, holes) through various mechanisms. The charge carriers may drift to one of the diode electrodes under an electric field. This electric field may be an external electric field. The electrical contact 119B may include multiple discrete portions, each of which is in electrical contact with the discrete region 114. The term "electrical contact" may be used interchangeably with the term "electrode." In one embodiment, the charge carriers may drift in multiple directions such that the charge carriers generated by a single radiation particle are not substantially shared by two different discrete regions 114 (here, "substantially not shared" means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow to a discrete region of the plurality of discrete regions 114 that is different from the discrete regions to which the remaining charge carriers flow). Charge carriers generated by radiation particles incident on the periphery of a footprint of one of the discrete regions 114 are substantially not shared by another of the discrete regions 114. A pixel 150 associated with a particular discrete region 114 may be an area around the discrete region 114 in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the charge carriers generated by radiation particles incident thereon flow toward the discrete region 114. That is, less than 2%, less than 1%, less than 0.1%, or less than 0.01% of the charge carriers flow out of the pixel 150.

[0034] Figure 4 Schematically shows an alternative embodiment Figure 1 Detailed cross-sectional view of radiation detector 100 along line 2-2. More specifically, radiation absorbing layer 110 may include resistors of semiconductor materials such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof, but not diodes. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest. In one embodiment, Figure 4 The electronic circuit layer 120 is similar in structure and function to Figure 3 The electronic circuit layer 120 is provided.

[0035] When radiation strikes the radiation-absorbing layer 110, which includes a resistor but no diode, it can be absorbed and generate one or more charge carriers through various mechanisms. A radiation particle can generate 10 to 100,000 charge carriers. These charge carriers can drift to electrical contacts 119A and 119B under an electric field. This electric field can be an external electric field. Electrical contact 119B can include multiple discrete sections. In one embodiment, charge carriers can drift in multiple directions such that charge carriers generated by a single radiation particle are substantially not shared by two different discrete sections of electrical contact 119B ("substantially not shared" herein means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow to a discrete section of the multiple discrete sections that is different from the discrete sections to which the remaining charge carriers flow). Charge carriers generated by a radiation particle incident on the periphery of the footprint of one of the discrete sections of electrical contact 119B are substantially not shared by another of the discrete sections of electrical contact 119B. A pixel 150 associated with a discrete portion of electrical contact 119B may be a region around the discrete portion in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the charge carriers generated by radiation particles incident therein flow toward the discrete portion of electrical contact 119B. That is, less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow out of the pixel associated with the discrete portion of electrical contact 119B.

[0036] The term "image" in this patent application (including claims) is not limited to the spatial distribution of radiation properties (such as intensity). For example, the term "image" can also include the spatial distribution of the density of a substance or element.

[0037] Imaging system

[0038] Figure 5 A perspective view of an imaging system 500 according to an embodiment is schematically shown. In one embodiment, the imaging system 500 may include a sample stage 540, an X-ray detector 505, and one or more cameras 510 (e.g., cameras 510.1 and 510.2). In one embodiment, the sample stage 540 may be between (A) the X-ray detector 505 and (B) the cameras 510.1 and 510.2 (as shown).

[0039] In one embodiment, sample stage 540 may include a window 542 for supporting a sample 590. Specifically, sample 590 may be positioned on a supporting surface 542ss of window 542 (as shown). In one embodiment, sample 590 may include human or animal tissue. In one embodiment, window 542 may not be opaque to X-rays.

[0040] In one embodiment, the X-ray detector 505 can be similar in structure and function to the Figures 1 to 4 In one embodiment, the X-ray detector 505 may be arranged such that the best fit plane 507 of all sensing elements 150 of the X-ray detector 505 is parallel to the support surface 542ss of the window 542 .

[0041] X-ray absorption image of the sample

[0042] In one embodiment, the X-ray detector 505 may capture an X-ray absorption image of a sample 590 located on the window 542 of the sample stage 540. Specifically, in one embodiment, the X-ray source 530 may transmit an X-ray beam 532 toward the sample 590; and the X-ray detector 505 may capture an X-ray absorption image of the sample 590 based on the interaction between the X-ray beam 532 and the sample 590.

[0043] The interaction between the X-ray beam 532 and the sample 590 may include situations such as the following: (A) a portion of the X-ray photons of the X-ray beam 532 incident on the sample 590 are absorbed by the sample 590, (B) a portion of the X-ray photons of the X-ray beam 532 incident on the sample 590 pass through the sample 590 without changing their direction, and (C) a portion of the X-ray photons of the X-ray beam 532 incident on the sample 590 collide with atoms of the sample 590 and thereby change their direction.

[0044] In one embodiment, the X-ray source 530 may be arranged such that the sample 590 is located between the X-ray source 530 and the X-ray detector 505. In one embodiment, the X-ray source 530 may be arranged such that a straight line (not shown) passing through the X-ray source 530 and the sample 590 is perpendicular to the support surface 542ss of the window 542.

[0045] Reference Figure 5 Although X-ray source 530 is shown as a point, X-ray source 530 may have any size and shape (ie, X-ray source 530 is not necessarily a point source).

[0046] Visible light and infrared images of the sample

[0047] In one embodiment, the camera 510 . 1 may capture a visible light image of the sample 590 ; and the camera 510 . 2 may capture an infrared light image of the sample 590 .

[0048] In one embodiment, substantially all of the photons from sample 590 that are detected by camera 510.1 to generate a visible light image of sample 590 may be within the first wavelength range of visible light. In this application, "substantially all" means at least 90%. In other words, substantially all of the photons from sample 590 that are detected by camera 510.1 to generate a visible light image of sample 590 are visible light photons.

[0049] Similarly, in one embodiment, substantially all of the photons from sample 590 that are detected by camera 510.2 to generate the infrared image of sample 590 may be within the second wavelength range of infrared light. In other words, substantially all of the photons from sample 590 that are detected by camera 510.2 to generate the infrared image of sample 590 are infrared photons.

[0050] In one embodiment, there may be no overlap between the X-ray wavelength range (i.e., 0.01 nm - 10 nm), the first wavelength range, and the second wavelength range. In other words, no wavelength is within at least two of the X-ray wavelength range, the first wavelength range, and the second wavelength range.

[0051] For example, the first wavelength range may be 500 nm - 600 nm (ie, within the visible light wavelength range of 400 nm - 700 nm); and the second wavelength range may be 800 nm - 900 nm (ie, within the infrared light wavelength range of 700 nm - 1 mm).

[0052] Operation of the imaging system

[0053] In one embodiment, the imaging system 500 may operate as follows: The X-ray detector 505 may capture an X-ray absorption image of the sample 590. The camera 510.1 may capture a visible light image of the sample 590. The camera 510.2 may capture an infrared light image of the sample 590.

[0054] In one embodiment, the X-ray absorption image, the visible light image, and the infrared light image may be captured simultaneously. In an alternative embodiment, the X-ray absorption image, the visible light image, and the infrared light image may be captured one image at a time.

[0055] In one embodiment, a composite image of the sample 590 may be generated by superimposing at least an X-ray absorption image, a visible light image, and an infrared light image.

[0056] Flowchart outlining the operation of the imaging system

[0057] Figure 6 shows an overview according to an embodiment Figure 5 Flowchart 600 of the operation of the imaging system 500.

[0058] In step 610, the operation may include taking an X-ray absorption image of the sample using an X-ray detector. For example, in the above embodiment, referring to Figure 5 , the X-ray detector 505 captures an X-ray absorption image of the sample 590 .

[0059] In step 620, the operation may include using M cameras to respectively capture images (i) of the sample, i = 1, ..., M. For example, in the above embodiment, referring to Figure 5 , camera 510.1 captures a visible light image of sample 590, and camera 510.2 captures an infrared light image of sample 590 (here, M = 2).

[0060] In step 630, the operation may include generating a composite image of the sample by superimposing at least (A) the X-ray absorption image and (B) the image (i), i = 1, ..., M. For example, in the above embodiment, referring to Figure 5 , a composite image of the sample 590 is generated by superimposing at least (A) the X-ray absorption image and (B) the visible light image and the infrared light image of the sample 590 .

[0061] Other embodiments

[0062] Transparencies used to create composite images

[0063] In one embodiment, referring to Figure 5 and Figure 6 In step 630, a composite image of sample 590 can be generated as follows. An X-ray transparency can be created for the X-ray absorption image. Furthermore, a first transparency can be created for the visible light image of sample 590, and a second transparency can be created for the infrared light image of sample 590. The X-ray transparency, the first transparency, and the second transparency can then be placed on top of each other and placed on a projector (not shown) for projecting the composite image of sample 590 onto a screen (not shown).

[0064] In one embodiment, the creation of the first transparent film may include correcting the trapezoidal distortion of the visible light image. Similarly, in one embodiment, the creation of the second transparent film may include correcting the trapezoidal distortion of the infrared light image.

[0065] In an embodiment, placing the X-ray transparency, the first transparency, and the second transparency on top of each other and on the projector may include aligning the images of the windows 542 on the X-ray transparency, the first transparency, and the second transparency.

[0066] In one embodiment, the X-ray transparent film, the first transparent film, and the second transparent film may have false colors.

[0067] Refractive index of the sample

[0068] In one embodiment, referring to Figure 5 The imaging system 500 may further include a mask 550, which may include N parallel slits, where N is a positive integer (e.g., three slits 552 as shown). In one embodiment, the three slits 552 and the X-ray source 530 form three X-ray fan beams 553 from the three slits 552, respectively. For simplicity, Figure 5 Only the X-ray fan beam 553 emitted from the middle slit 552 is shown (ie, the remaining two X-ray fan beams 553 emitted from the remaining two slits 552 are not shown).

[0069] In one embodiment, the mask 550 can be translated in a direction 555 perpendicular to the three slits 552 so that the three X-ray fan beams 553 and the X-ray detector 505 scan the entire sample 590. Note that if the refractive index of the sample 590 is uniform throughout the sample 590, the sample 590 should not cause any distortion, and the system operator should expect to see an illumination stripe on the X-ray detector 505 that matches the shape of the slits 552. Distortion of the illumination stripe on the X-ray detector 505, if any, indicates that the refractive index of the sample 590 is not uniform.

[0070] X-ray phase contrast image of the sample

[0071] In one embodiment, referring to Figure 5 , the X-ray detector 505 can be configured to move along a direction 506 between two separate positions (as shown in the figure) that are respectively close to and far away from the sample 590. The X-ray detector 505 is configured to capture two X-ray images of the sample 590 from the two positions, respectively, and the imaging system 500 is configured to generate an X-ray phase contrast image of the sample 590 based on the two X-ray images.

[0072] In one embodiment, the direction 506 may not be parallel to the support surface 542ss of the window 542. For example, the direction 506 may be perpendicular to the support surface 542ss of the window 542 (as shown).

[0073] In one embodiment, if Figure 6 The generation of the composite image of the sample 590 described in step 630 may include superimposing (A) an X-ray absorption image of the sample 590 , (B) a visible light image and an infrared light image of the sample 590 , and (C) an X-ray phase contrast image on the sample 590 .

[0074] processor

[0075] In an embodiment, the imaging system 500 may include a processor (not shown) configured to generate a composite image of the sample 590 by superimposing at least an X-ray absorption image, a visible light image, and an infrared light image of the sample 590 .

[0076] The sample has a uniform thickness

[0077] In one embodiment, referring to Figure 5 The imaging system 500 may include a plate (not shown) that presses the sample 590 against the window 542 of the sample stage 540 so that the thickness of the sample 590 measured in a direction perpendicular to the support surface 542ss of the window 542 is uniform.

[0078] In one embodiment, the plate may not be non-transparent to any photons of X-rays, visible light, and infrared light, so that the plate does not interfere with the capture of X-ray absorption images, visible light images, and infrared light images.

[0079] X-rays do not strike the camera

[0080] In one embodiment, referring to Figure 5 , no X-ray photons from X-ray source 530 may strike any of cameras 510 . 1 and 510 . 2 .

[0081] X-ray source and camera close to each other

[0082] In one embodiment, referring to Figure 5 , X-ray source 530 and cameras 510.1 and 510.2 can be within a right circular cone 560 having (A) an apex located on sample X 590 and (B) an opening angle α of at most 10 degrees, at most 20 degrees, at most 30 degrees, or at most 40 degrees. In one embodiment, axis 562 of right circular cone 560 can be perpendicular to best fit plane 507.

[0083] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A system comprising: X-ray detectors; M cameras (camera(i), i = 1, ..., M), where M is a positive integer; and a sample stage including a window that is not non-transparent to X-rays, wherein the X-ray detector is configured to capture an X-ray absorption image of the sample located on the window of the sample stage, wherein, for each value of i, the camera (i) is configured to take an image (i) of the sample, wherein, for each value of i, substantially all of the photons from the sample detected by the camera (i) to produce the image (i) belong to wavelength range (i), and There is no overlap between the wavelength range of the X-ray and the wavelength range (i), i = 1, ..., M.

2. The system according to claim 1, further comprising a mask comprising N parallel slits, wherein the N slits are used to form N X-ray fan beams from the N slits, respectively, N is a positive integer, wherein the mask is configured to translate in a direction perpendicular to the N slits so that the N X-ray fan beams and the X-ray detector scan the entire sample.

3. The system according to claim 1, in, M = 1， Wherein, the wavelength range (1) is visible light.

4. The system according to claim 1, in, M = 1， Wherein, the wavelength range (1) is infrared light.

5. The system according to claim 1, in, M = 2， Wherein, the wavelength range (1) is visible light, Wherein, the wavelength range (2) is infrared light.

6. The system according to claim 1, wherein: M > 2。 7. The system according to claim 1, in, The X-ray detector is configured to move between two separate positions close to and far from the sample, respectively, wherein the X-ray detector is configured to take two X-ray images of the sample from the two positions respectively, and The system is configured to generate an X-ray phase contrast image of the sample based on the two X-ray images.

8. The system of claim 1, further comprising a processor configured to generate a composite image of the sample by superimposing at least the X-ray absorption image and the image (i), i = 1, ..., M.

9. The system according to claim 1, further comprising a plate that presses the sample against the window of the sample stage so that the thickness of the sample measured in a direction perpendicular to the support surface of the window is uniform, wherein The plate is not non-transparent to X-rays and photons of the wavelength range (i), i=1, . . . ,M.

10. The system according to claim 1, further comprising an X-ray source for capturing the X-ray absorption image, wherein No X-ray photons from the X-ray source strike any of the M cameras.

11. The system according to claim 1, wherein: The sample stage is located between the X-ray detector and the M cameras.

12. The system according to claim 1, further comprising an X-ray source for capturing the X-ray absorption image, wherein The X-ray source and the M cameras are within a right circular cone having a vertex located on the sample and an opening angle of a maximum of 10 degrees, a maximum of 20 degrees, a maximum of 30 degrees, or a maximum of 40 degrees.

13. The system according to claim 12, wherein: The axis of the right circular cone is perpendicular to the best-fit plane of all sensing elements of the X-ray detector.

14. The system according to claim 1, wherein: The sample includes human or animal tissue.

15. A method of using the system according to claim 1, comprising: capturing the X-ray absorption image of the sample using the X-ray detector; Use the M cameras to respectively capture the image (i) of the sample, where i = 1, ..., M; as well as A composite image of the sample is generated by superimposing at least the X-ray absorption image and the image (i), i=1, . . . , M.

16. The method according to claim 15, in, The system further includes a mask comprising N parallel slits, wherein N is a positive integer, and The method further includes forming N X-ray fan beams from the N slits respectively, and translating the mask in a direction perpendicular to the N slits, thereby scanning the entire sample using the N X-ray fan beams and the X-ray detector.

17. The method according to claim 15, further comprising: capturing two X-ray images of the sample using the X-ray detector from two separate positions, close to and far from the sample, respectively; as well as generating an X-ray phase contrast image of the sample based on the two X-ray images, The generating of the composite image includes superimposing the X-ray absorption image, the image (i) and the X-ray phase contrast image, where i = 1, ..., M.

Images