Dual-energy dual-resolution x-ray detector, detection system and imaging method

Abstract

The application discloses a dual-energy dual-resolution X-ray detector, a detection system and an imaging method. The detector comprises a first visible light sensor, a first fluorescent material layer, a packaging material layer, a second fluorescent material layer and a second visible light sensor which are arranged in layers. The first visible light sensor is closer to an X-ray source than the second visible light sensor, and the resolution of the first visible light sensor is higher than that of the second visible light sensor. The first visible light sensor absorbs visible photons generated by the first fluorescent material layer excited by X-rays. The second visible light sensor absorbs visible photons generated by the second fluorescent material layer excited by X-rays. The packaging material layer is used to isolate the visible photons generated by the first fluorescent material layer excited by X-rays from the visible photons generated by the second fluorescent material layer excited by X-rays. The upper and lower detectors of the system can output high-resolution images and high-energy absorption images respectively, and the images of interest can also be obtained through image algorithms.

Description

Technical Field

[0001] The present invention relates to the field of X-ray detector imaging, and in particular to a dual-energy spectrum dual-resolution X-ray detector, a detection system and an imaging method. Background Art

[0002] In an X-ray imaging system, the detector plays a decisive role in the imaging of the system. In the imaging system, it is hoped that X-rays of different energies can be presented simultaneously. In order to be able to display tissues of different densities, it is hoped that the imaging system can have different resolutions. The demand for dual-energy and dual-resolution angiography in the DSA function of large C systems is becoming increasingly clear.

[0003] The principle of using dual-energy imaging in CT systems currently is to use different energy sources to achieve dual-energy imaging. However, switching energy sources during the switching process takes a certain amount of time, affecting the efficiency of the system. There is also the possibility that the object being measured moves, forming motion artifacts.

[0004] In actual use, different resolutions are required. Different tissues need to be distinguished when used in different parts, and the detector needs to have high resolution at the same time.

[0005] Such application scenarios place very high demands on the system. It needs to have the ability to detect high and low energy spectra while also having very high resolution. Such requirements also require the detector to have dual-energy spectrum detection capabilities and provide different resolutions at the same time. The detection system in the existing technology cannot meet such high performance requirements well. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a dual-energy spectrum, dual-resolution X-ray detector, detection system, and imaging method. The upper and lower detector layers can output high-resolution images and high-energy absorption images, respectively, and can also generate images of interest through image algorithms. The technical solution is as follows:

[0007] In one aspect, the present invention provides a dual-energy spectrum, dual-resolution X-ray detector comprising a first visible light sensor, a first fluorescent material layer, an encapsulation material layer, a second fluorescent material layer, and a second visible light sensor stacked in sequence, wherein the first visible light sensor is closer to an X-ray source than the second visible light sensor, and the first visible light sensor has a higher resolution than the second visible light sensor.

[0008] The first visible light sensor is used to absorb visible photons generated by the first fluorescent material layer being excited by X-rays; the second visible light sensor is used to absorb visible photons generated by the second fluorescent material layer being excited by X-rays; the packaging material spacer is used to isolate the visible photons generated by the first fluorescent material layer being excited by X-rays from the visible photons generated by the second fluorescent material layer being excited by X-rays.

[0009] Furthermore, the thickness of the second fluorescent material layer is greater than the thickness of the first fluorescent material layer.

[0010] Furthermore, the dual-energy spectrum dual-resolution X-ray detector also includes a packaging material wall layer arranged along the sides of the first fluorescent material layer and the second fluorescent material layer, and one edge of the packaging material wall layer is against the first visible light sensor, and the other edge is against the second visible light sensor.

[0011] Furthermore, the first visible light sensor and the second visible light sensor have the same shape and size, the first fluorescent material layer and the second fluorescent material layer have the same shape and size, the area of ​​the first visible light sensor is larger than the first fluorescent material layer, and the packaging material wall layer has a recessed structure relative to the first visible light sensor and the second visible light sensor.

[0012] Furthermore, the packaging material partition layer and the packaging material wall layer are both made of X-ray fluorescence packaging materials, and the packaging materials are aluminum film and hot melt adhesive.

[0013] Furthermore, the X-ray-to-visible-light conversion material contained in the first fluorescent material layer and the second fluorescent material layer is cesium iodide or other scintillators.

[0014] On the other hand, the present invention provides a dual-energy spectrum dual-resolution X-ray detection system, including an X-ray source, a first image acquisition device, a second image acquisition device and the dual-energy spectrum dual-resolution X-ray detector as described above, wherein the first image acquisition device is electrically connected to a first visible light sensor to acquire a first image, and the second image acquisition device is electrically connected to a second visible light sensor to acquire a second image.

[0015] Furthermore, the dual-energy spectrum dual-resolution X-ray detection system also includes a processor, which is electrically connected to the first image acquisition device and the second image acquisition device, and the processor can perform image calculation processing on the first image acquired by the first image acquisition device and the second image acquired by the second image acquisition device.

[0016] In another aspect, the present invention provides an imaging method based on the above-mentioned dual-energy spectrum dual-resolution X-ray detection system, comprising the following steps:

[0017] Turning on the X-ray source so that it emits X-rays toward the first visible light sensor of the X-ray detection system;

[0018] If the target obtains a high-resolution image, outputting the first image captured by the first image capture device;

[0019] If the target obtains a high-energy absorption image, the second image captured by the second image capturing device is output.

[0020] Furthermore, the imaging method further comprises:

[0021] A processor is used to perform image calculation processing on the first image and the second image to obtain a synthesized combined image.

[0022] The beneficial effects brought about by the technical solution provided by the present invention are as follows:

[0023] a. Using two layers of visible light sensors with different resolutions, the high-resolution visible light sensor outputs a high-resolution image;

[0024] b. The two fluorescent material layers are separated by an encapsulating material. X-rays passing through one fluorescent material layer and through both fluorescent material layers form two different energy spectra. The X-rays penetrating the second fluorescent material layer have a high-energy spectrum, and a corresponding high-energy absorption image is obtained.

[0025] c. Applying different image algorithms, we can obtain the image of interest, and then output the combined image of interest after balancing the resolution and quantum detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 1 is a schematic structural diagram of a dual-energy spectrum dual-resolution X-ray detector provided by an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the structure of a dual-energy spectrum dual-resolution X-ray detection system provided by an embodiment of the present invention.

[0029] The reference numerals include: 1-first visible light sensor, 2-second visible light sensor, 3-first fluorescent material layer, 4-second fluorescent material layer, 5-encapsulation material spacer layer, 6-encapsulation material wall layer. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0031] The present invention provides a dual-energy spectrum dual-resolution X-ray detector, see Figure 1 , which comprises a first visible light sensor 1, a first fluorescent material layer 3, an encapsulation material spacer 5, a second fluorescent material layer 4 and a second visible light sensor 2 stacked in sequence, wherein the first visible light sensor 1 and the second visible light sensor 2 are two TFT flat panels with different resolutions, specifically, for example Figure 1 As shown, the first visible light sensor 1 is closer to the X-ray source than the second visible light sensor 2 , and the resolution of the first visible light sensor 1 is set to be greater than that of the second visible light sensor 2 .

[0032] The first visible light sensor 1 is used to absorb visible photons generated by the first fluorescent material layer 3 being excited by X-rays; the second visible light sensor 2 is used to absorb visible photons generated by the second fluorescent material layer 4 being excited by X-rays.

[0033] like Figure 1 As shown, the dual-energy spectrum, dual-resolution X-ray detector further includes a packaging material wall layer 6 disposed along the sides of the first fluorescent material layer 3 and the second fluorescent material layer 4. One edge of the packaging material wall layer 6 abuts the first visible light sensor 1, and the other edge abuts the second visible light sensor 2. The packaging material barrier layer 5 and the packaging material wall layer 6 collectively serve to isolate visible photons generated by X-ray excitation of the first fluorescent material layer 3 from visible photons generated by X-ray excitation of the second fluorescent material layer 4. In one embodiment of the present invention, the packaging material barrier layer 5 and the packaging material wall layer 6 are both made of an X-ray fluorescence packaging material, preferably an aluminum film and hot melt adhesive.

[0034] In a preferred embodiment of the present invention, the thickness of the second fluorescent material layer 4 is greater than that of the first fluorescent material layer 3. Optionally, the X-ray-to-visible-light material contained in the first fluorescent material layer 3 and the second fluorescent material layer 4 is cesium iodide (CsI) or other scintillators. In the embodiment of the present invention, the X-ray-to-visible-light materials of the first fluorescent material layer 3 and the second fluorescent material layer 4 can be the same or different. The other scintillators can be high-density Cherenkov crystal materials modified to make them into scintillating crystals, such as PbF2, NaBi(WO4)2, etc.; or NaI:Tl or CsI:Tl crystals, etc. Among them, the reason why the second fluorescent material layer 4 is thicker is that the energy spectrum of the X-rays that pass through the first fluorescent material layer 3 and enter the second fluorescent material layer 4 becomes narrower and the rays harden, that is, the intensity of the X-rays entering the second fluorescent material layer 4 becomes higher. In order to ensure that the second fluorescent material layer 4 can absorb high-intensity X-rays, assuming that the number of photons absorbed by the first visible light sensor 1 is close to or the same as the number of photons absorbed by the second visible light sensor 2, the thickness of the second fluorescent material layer 4 is greater than that of the first fluorescent material layer 3. Otherwise, most of the X-rays will be absorbed in the first fluorescent material layer 3, which will affect the photon absorption of the second visible light sensor 2 and the imaging quality of the detector below it.

[0035] See also Figure 1 The first visible light sensor 1 and the second visible light sensor 2 have the same shape and size, that is, the first image formed by the first visible light sensor 1 and the second image formed by the second visible light sensor 2 are two images obtained by imaging the same object, and the imaging size and angle of the object in the two images are the same, which provides the possibility of applying various image algorithms to the two images; the first fluorescent material layer 3 and the second fluorescent material layer 4 have the same shape and size, the area of ​​the first visible light sensor 1 is larger than the first fluorescent material layer 3, and the packaging material wall layer 6 has a recessed structure relative to the first visible light sensor 1 and the second visible light sensor 2, ensuring that the visible photons generated by the first fluorescent material layer 3 excited by X-rays can be efficiently absorbed by the first visible light sensor 1, and ensuring that the visible photons generated by the second fluorescent material layer 4 excited by X-rays can be efficiently absorbed by the second visible light sensor 2.

[0036] In one embodiment of the present invention, a dual-energy spectrum dual-resolution X-ray detection system is provided, such as Figure 2As shown, the X-ray detection system includes an X-ray source, a first image acquisition device, a second image acquisition device, and the dual-energy spectrum, dual-resolution X-ray detector described above. The first image acquisition device is electrically connected to the first visible light sensor 1 to acquire a first image, and the second image acquisition device is electrically connected to the second visible light sensor 2 to acquire a second image. This X-ray detection system can output two types of images in a single exposure: low-energy X-rays absorbed by the first fluorescent material layer 3 are converted into visible photons that are absorbed by the high-resolution first visible light sensor 1. Accordingly, the first image acquisition device acquires a high-resolution image, which has excellent imaging effects on low-density tissues and can produce very clear images; X-rays not absorbed by the first fluorescent material layer 3 penetrate the second fluorescent material layer 4, where their energy spectrum changes (narrows) and hardens, increasing the intensity of the rays. X-rays are absorbed in the second fluorescent material layer 4 and converted into visible photons that are absorbed by the low-resolution second visible light sensor 2. Accordingly, the second image acquisition device acquires a high-energy absorption image. High-energy X-ray imaging is suitable for imaging high-density tissues, such as breasts. It should be noted that the low resolution of the second visible light sensor 2 here is relative to the high resolution of the first visible light sensor 1. If the resolution of the second visible light sensor 2 is too high, the pixel size will be too small, which will be detrimental to the absorption of visible photons by the second visible light sensor 2. Therefore, the second visible light sensor 2 with too high a resolution may be unable to form an image due to its low visible light absorption efficiency.

[0037] In a preferred embodiment, the dual-energy spectrum, dual-resolution X-ray detection system further includes a processor electrically connected to the first and second image acquisition devices, capable of performing image processing on the first image captured by the first image acquisition device and the second image captured by the second image acquisition device. In this embodiment, the X-ray detection system can output three image formats from a single exposure. In addition to the aforementioned high-resolution image and high-energy absorption image, it can also output a combined image. The combined image can be obtained by performing image addition, subtraction, or other image processing operations on the first and second images.

[0038] In one embodiment of the present invention, an imaging method based on the above-mentioned dual-energy spectrum dual-resolution X-ray detection system is provided, comprising the following steps:

[0039] Turning on the X-ray source so that it emits X-rays toward the first visible light sensor of the X-ray detection system;

[0040] If the target is to obtain a high-resolution image, the first image x1 acquired by the first image acquisition device is output. For example, if an X-ray is currently taken of an orthopedic patient, the first image x1 is selected for output;

[0041] If the target obtains a high-energy absorption image, the second image x2 acquired by the second image acquisition device is output. For example, if an X-ray is currently taken for a breast patient, the second image x2 is selected for output.

[0042] Furthermore, the imaging method further comprises:

[0043] The processor performs image calculation processing on the first image x1 and the second image x2 to obtain a composite image f(x1)+f(x2). For example, if the imaging is currently of relatively thick but low-density tissue, such as a hip joint, it is necessary to perform subtraction processing on the first image and the second image. After balancing the resolution and quantum detection efficiency, the composite image of interest can be output. The image algorithm f(x1)+f(x2) performed on the first image and the second image in the present invention can be any image synthesis algorithm in the prior art and will not be described in detail here.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dual-energy spectrum dual-resolution X-ray detector, characterized in that: The X-ray detector is composed of a packaging material wall layer (6) and a first visible light sensor (1), a first fluorescent material layer (3), a packaging material spacer (5), a second fluorescent material layer (4) and a second visible light sensor (2) stacked in sequence. The first visible light sensor (1) and the second visible light sensor (2) are respectively the upper and lower outer surfaces of the X-ray detector. The first visible light sensor (1) is closer to the X-ray source than the second visible light sensor (2). The resolution of the first visible light sensor (1) is greater than that of the second visible light sensor (2). The first visible light sensor (1) is used to absorb visible photons generated by the first fluorescent material layer (3) being excited by X-rays; the second visible light sensor (2) is used to absorb visible photons generated by the second fluorescent material layer (4) being excited by X-rays; and the packaging material spacer (5) is used to isolate visible photons generated by the first fluorescent material layer (3) being excited by X-rays from visible photons generated by the second fluorescent material layer (4) being excited by X-rays. The packaging material wall layer (6) is arranged along the side of the first fluorescent material layer (3) and the second fluorescent material layer (4), and one edge of the packaging material wall layer (6) abuts against the first visible light sensor (1), and the other edge abuts against the second visible light sensor (2), and the packaging material wall layer (6) is in a recessed structure relative to the first visible light sensor (1) and the second visible light sensor (2); the packaging material spacer (5) and the packaging material wall layer (6) are both made of X-ray fluorescence packaging material, and the packaging material is aluminum film and hot melt adhesive.

2. The dual-energy spectrum dual-resolution X-ray detector according to claim 1, characterized in that: The thickness of the second fluorescent material layer (4) is greater than the thickness of the first fluorescent material layer (3).

3. The dual-energy spectrum dual-resolution X-ray detector according to claim 1, characterized in that: The first visible light sensor (1) and the second visible light sensor (2) have the same shape and size, the first fluorescent material layer (3) and the second fluorescent material layer (4) have the same shape and size, and the area of ​​the first visible light sensor (1) is larger than that of the first fluorescent material layer (3).

4. The dual-energy spectrum dual-resolution X-ray detector according to claim 1, characterized in that: The X-ray-to-visible-light material contained in the first fluorescent material layer (3) and the second fluorescent material layer (4) is cesium iodide or PbF 2 crystals or NaBi ( WO 4) 2 crystals or NaI:Tl Crystal or CsI:Tl crystal.

5. A dual-energy spectrum dual-resolution X-ray detection system, characterized in that: The invention comprises an X-ray source, a first image acquisition device, a second image acquisition device and a dual-energy spectrum dual-resolution X-ray detector as described in any one of claims 1 to 4, wherein the first image acquisition device is electrically connected to a first visible light sensor (1) to acquire a first image, and the second image acquisition device is electrically connected to a second visible light sensor (2) to acquire a second image.

6. The dual-energy spectrum dual-resolution X-ray detection system according to claim 5, characterized in that: It also includes a processor, which is electrically connected to the first image acquisition device and the second image acquisition device. The processor can perform image calculation processing on the first image acquired by the first image acquisition device and the second image acquired by the second image acquisition device.

7. An imaging method based on the dual-energy spectrum dual-resolution X-ray detection system according to claim 5, characterized in that: The following steps are involved: Turning on the X-ray source so that it emits X-rays toward the first visible light sensor of the X-ray detection system; If the target obtains a high-resolution image, outputting the first image captured by the first image capture device; If the target obtains a high-energy absorption image, the second image captured by the second image capturing device is output.

8. The imaging method according to claim 7, wherein: Based on the dual-energy spectrum dual-resolution X-ray detection system according to claim 6, the imaging method further includes: A processor is used to perform image calculation processing on the first image and the second image to obtain a synthesized combined image.

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