WO2021164281A1

WO2021164281A1 - Dual energy spectrum dual resolution x-ray probes, probe system, and imaging method

Info

Publication number: WO2021164281A1
Application number: PCT/CN2020/121196
Authority: WO
Inventors: 徐永; 程佳
Original assignee: 江苏康众数字医疗科技股份有限公司
Priority date: 2020-02-21
Filing date: 2020-10-15
Publication date: 2021-08-26
Also published as: CN111198397A

Abstract

Dual energy spectrum dual resolution X-ray probes, a probe system, and an imaging method. The probes comprise a first visible light sensor (1), a first fluorescent material layer (3), an encapsulation material separation layer (5), a second fluorescent material layer (4), and a second visible light sensor (2), all of which are in an overlapping layer arrangement; the first visible light sensor (1) is closer to an X-ray source than the second visible light sensor (2), and 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) absorbs visible light photons produced by the first fluorescent material layer (3) under X-ray excitation, and the second visible light sensor (2) absorbs visible light photons produced by the second fluorescent material layer (4) under X-ray excitation; and the encapsulation material separation layer (5) is used for separating the visible light photons produced by the first fluorescent material layer (3) under X-ray excitation from the visible light photons produced by the second fluorescent material layer (4) under X-ray excitation. Upper and lower layer probes of the probe system can respectively output high resolution images and high energy absorption images, and images of interest can further be obtained by means of an image algorithm.

Description

X-ray detector with dual energy spectrum and dual resolution, detection system and imaging method

Priority statement

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 202010107082.5 on February 21, 2020, the entire content of which is incorporated into this application by reference.

Technical field

The invention relates to the imaging field of X-ray detectors, in particular to an X-ray detector with dual energy spectrum and dual resolution, a detection system and an imaging method.

Background technique

The detector in the X-ray imaging system 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 displayed at the same time, and in order to display tissues of different densities, it is hoped that the imaging system can have different The need for dual-energy and dual-resolution angiography with DSA function in the large C system is becoming more and more clear.

At present, the principle of dual-energy imaging in CT systems is to use different energy sources to achieve dual-energy imaging, but it takes a certain amount of time to switch between energy sources during the switching process, which affects the efficiency of the system, and there is a movement of the measured object Possibly, movement artifacts are formed.

In actual use, different resolutions are needed. In the use of different parts, different tissues need to be distinguished, and the detector needs to have a higher resolution capability at the same time.

Such application scenarios place high requirements on the system, requiring both high- and low-energy spectrum detection capabilities and high resolution. This requirement also requires the detector to have dual-energy spectrum detection capabilities, and at the same time Different resolutions can be provided, and the detection system in the prior art cannot meet such high performance requirements well.

Summary of the invention

In order to solve the problems 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 detectors can respectively output high-resolution images and high-energy absorption images. , You can also get the image of interest through image algorithm. The technical solution is as follows:

In one aspect, the present invention provides an X-ray detector with dual energy spectrum and dual resolution, including a first visible light sensor, a first fluorescent material layer, a packaging material spacer, a second fluorescent material layer, and a first visible light sensor, a first fluorescent material layer, a second fluorescent material layer, and a 2. a visible light sensor, the first visible light sensor is closer to the X-ray source than the second visible light sensor, and the resolution of the first visible light sensor is greater than that of the second visible light sensor;

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 visible photons; the encapsulation material spacer is used to isolate the visible photons generated by the X-ray excitation of the first fluorescent material layer and the visible photons generated by the X-ray excitation of the second fluorescent material layer.

Further, the thickness of the second fluorescent material layer is greater than the thickness of the first fluorescent material layer.

Further, the dual-energy spectrum dual-resolution X-ray detector further includes a packaging material wall layer provided along the sides of the first fluorescent material layer and the second fluorescent material layer, and the packaging material wall layer One edge of the encapsulation material abuts the first visible light sensor, the other edge abuts the second visible light sensor, and the edge of the encapsulation material barrier layer abuts the inner surface of the encapsulation material wall layer.

Further, 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, and the area of the first visible light sensor is larger than that of the first visible light sensor. The fluorescent material layer and the packaging material wall layer have a recessed structure relative to the first visible light sensor and the second visible light sensor.

Further, the encapsulation material barrier layer and the encapsulation material wall layer are both made of X fluorescent encapsulation material, and the encapsulation material is aluminum film and hot melt adhesive.

Further, the X-ray conversion material contained in the first fluorescent material layer and the second fluorescent material layer is cesium iodide, PbF ₂ crystal, NaBi(WO ₄ ) ₂ crystal, NaI:Tl crystal or CsI:Tl crystal.

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 aforementioned dual-energy spectrum dual-resolution X-ray detection system. A high-speed X-ray detector, the first image acquisition device is electrically connected with a first visible light sensor to acquire a first image, and the second image acquisition device is electrically connected with a second visible light sensor to acquire a second image.

Further, the dual-energy spectrum dual-resolution X-ray detection system further includes a processor that is electrically connected to the first image acquisition device and the second image acquisition device, and the processor is capable of The first image collected by the first image collecting device and the second image collected by the second image collecting device are processed for image operation.

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

Turn on the X-ray source to emit X-rays to the first visible light sensor of the X-ray detection system;

If the target obtains a high-resolution image, output the first image collected by the first image collection device;

If the target obtains a high-energy absorption image, the second image collected by the second image collecting device is output.

Further, the imaging method further includes:

A processor is used to perform image arithmetic processing on the first image and the second image to obtain a synthesized combined image.

The beneficial effects brought by the technical solution provided by the present invention are as follows:

a. Use the upper and lower layers of visible light sensors with different resolutions, and the high-resolution visible light sensor outputs high-resolution images;

b. The two fluorescent material layers are separated by encapsulation materials, and the X-rays passing through one fluorescent material layer and the two fluorescent material layers form two different energy spectra, in which the X of the second fluorescent material layer penetrates -The ray is in the high-energy spectrum, and the high-energy absorption image is obtained accordingly;

c. Using different image algorithms, you can get the image of interest, and output the combined image of interest after balancing the resolution and quantum detection efficiency.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative work.

FIG. 1 is a schematic structural diagram of an X-ray detector with dual energy spectrum and dual resolution provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a dual-energy spectrum dual-resolution X-ray detection system provided by an embodiment of the present invention.

Wherein, the reference signs include: 1-first visible light sensor, 2-second visible light sensor, 3-first fluorescent material layer, 4-second fluorescent material layer, 5-packaging material barrier layer, 6-packaging material wall layer .

Detailed ways

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 described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The present invention provides a dual-energy spectrum dual-resolution X-ray detector. See Figure 1, which includes a first visible light sensor 1, a first fluorescent material layer 3, a packaging material spacer 5, and a second The fluorescent material layer 4 and the second visible light sensor 2, wherein the first visible light sensor 1 and the second visible light sensor 2 are two TFT plates with different resolutions. Specifically, as shown in FIG. 1, the first If the 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 set to be greater than that of the second visible light sensor 2.

The first visible light sensor 1 is used to absorb the 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 the X-rays generated by the second fluorescent material layer 4 Visible photons generated by the excitation of rays.

As shown in FIG. 1, the dual-energy spectrum dual-resolution X-ray detector further includes a packaging material wall layer 6 arranged along the sides of the first fluorescent material layer 3 and the second fluorescent material layer 4, and One edge of the packaging material wall layer 6 is against the first visible light sensor 1, the other edge is against the second visible light sensor 2, and the edge of the packaging material barrier layer 5 is against the inner surface of the packaging material wall layer 6. . The encapsulation material spacer layer 5 and the encapsulation material wall layer 6 are jointly used to isolate the visible photons generated by the X-ray excitation of the first fluorescent material layer 3 and the second fluorescent material layer 4 generated by the X-ray excitation Visible photons. In an embodiment of the present invention, the packaging material spacer 5 and the packaging material wall layer 6 are both made of X fluorescent packaging materials, and the packaging materials are preferably aluminum films and hot melt adhesives. Specifically, The aluminum film is packaged by hot melt adhesive. Further, the aluminum film of the packaging material wall layer 6 is installed between the first visible light sensor 1 and the second visible light sensor 2 by hot melt adhesive to form the X -The side wall of the radiation detector; the aluminum film of the packaging material barrier layer 5 is bonded to the aluminum film of the packaging material wall layer 6 by hot melt adhesive to connect the packaging material wall layer 6 with the upper and lower visible light layers The space enclosed by the sensors (the first visible light sensor 1 on the upper layer and the second visible light sensor 2 on the lower layer) is divided into upper and lower layers. As can be seen in conjunction with FIG. The first fluorescent material layer 3 and the lower space are used to fill the second fluorescent material layer 4.

In a preferred embodiment of the present invention, the thickness of the second fluorescent material layer 4 is greater than the thickness of the first fluorescent material layer 3. Optionally, the X-ray conversion 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 first fluorescent material The X-ray to visible light materials of layer 3 and second fluorescent material layer 4 can be the same or different. The other scintillators mentioned above can be modified high-density Cherenkov crystal materials to make them into scintillation crystals, such as PbF ₂ , NaBi (WO ₄ ) ₂ and other crystals; it can also be NaI:Tl or CsI:Tl crystals and so on. The reason why the second fluorescent material layer 4 is thicker is that the X-ray energy spectrum passing through the first fluorescent material layer 3 and entering the second fluorescent material layer 4 is narrowed and the rays are hardened, that is, entering the second fluorescent material layer 4 The intensity of X-rays of the fluorescent material layer 4 becomes higher. In order to ensure that the second fluorescent material layer 4 can absorb high-intensity X-rays, it is assumed that the photons absorbed by the first visible light sensor 1 and the photons absorbed by the second visible light sensor 2 If the number is close or the same, 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 second visible light. The photon absorption of sensor 2 and the imaging quality of the underlying detector.

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 for the same object. The two images obtained by imaging, the size and angle of the object in these two images are the same, which provides the possibility to apply various image algorithms to the two images; the shape of the first fluorescent material layer 3 and the second fluorescent material layer 4 Same as the 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 , So that there are no gaps between the packaging material wall layer 6 and the side walls of the first fluorescent material layer 3 and the second fluorescent material layer 4, so as to ensure that the first fluorescent material layer 3 is excited by X-rays. The visible photons can be efficiently absorbed by the first visible light sensor 1, and it is ensured that the visible photons generated by the second fluorescent material layer 4 being excited by X-rays can be efficiently absorbed by the second visible light sensor 2.

In an embodiment of the present invention, a dual-energy spectrum dual-resolution X-ray detection system is provided. As shown in FIG. 2, the X-ray detection system includes an X-ray source and a first image acquisition device. , A second image acquisition device and the above-mentioned dual energy spectrum dual resolution X-ray detector, the first image acquisition device is electrically connected to the first visible light sensor 1 to acquire a first image, the second image The collecting device is electrically connected with the second visible light sensor 2 to collect the second image. This X-ray detection system can output two forms of images at one exposure. The first fluorescent material layer 3 absorbs low-energy X-rays and converts them into visible photons that are absorbed by the first visible light sensor 1 with high resolution. The first image acquisition device collects and obtains high-resolution images, which have a good imaging effect on low-density tissues, and can obtain very clear images; X-rays that are not absorbed by the first fluorescent material layer 3 penetrate The second fluorescent material layer 4 changes (narrows) the energy spectrum and is hardened, and the ray intensity becomes higher, which is absorbed in the second fluorescent material layer 4 and converted into visible photons to be absorbed by the second visible light sensor 2 with low resolution. Correspondingly, the second image acquisition device acquires high-energy absorption images, and high-energy X-ray imaging is suitable for imaging tissues with higher density, 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 Too small a size is not conducive to the absorption of visible photons by the second visible light sensor 2. Therefore, the second visible light sensor 2 with too high resolution may not be able to image due to the low absorption efficiency of visible photons.

In a preferred embodiment, the dual-energy spectrum dual-resolution X-ray detection system further includes a processor that is electrically connected to the first image acquisition device and the second image acquisition device, and The processor can perform image operation processing on the first image collected by the first image collecting device and the second image collected by the second image collecting device. In this embodiment, the X-ray detection system can output three forms of images at one exposure. In addition to the above-mentioned high-resolution images and high-energy absorption images, it can also output a combined image. The combined image can be a comparison of the first image. Perform image addition or subtraction or other more image processing operations with the second image.

The working process of the dual-energy spectrum dual-resolution X-ray detection system is as follows:

When X-rays carrying information of the subject are irradiated to the X-ray imaging system of the first layer, part of the X-ray photons are absorbed by the X-ray imaging system of the first layer and generate a digital image; further, the unabsorbed X-ray photons will continue to penetrate the X-ray imaging system of the first layer and then reach the X-ray imaging system of the next layer, and be absorbed by the flat-panel detector of the next layer and converted into digital signals. Obviously, it penetrates The X-ray energy spectrum of the first layer reaching the detector surface of the next layer is weaker than the energy spectrum reaching the first layer. In this way, by designing the material and thickness of each layer of the fluorescent material (that is, the first fluorescent material layer 3 and the second fluorescent material layer 4) and the intermediate filter (that is, the encapsulating material spacer 5), it is possible to reach each The X-ray spectrum of the layer is tailored to capture information of a specific energy spectrum. Further, by comparing the original X-ray energy spectrum (the energy spectrum before entering the object) and the two-dimensional space image of the object obtained by the X-ray imaging system of each layer, the X-ray of the object can be restored. -Ray energy spectrum absorption characteristics, the dual energy spectrum detector can be well applied in the field of angiography.

Since the two-dimensional spatial image of the object is obtained at the same time, the flat-panel detector adopting a layered design can obtain efficient collection and utilization of various information including time, space, and energy spectrum.

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

If the target obtains a high-resolution image, output the first image x1 collected by the first image acquisition device. For example, if an X-ray film is currently taken on an orthopedic patient, the first image x1 is selected to be output;

If the target obtains a high-energy absorption image, the second image x2 collected by the second image acquisition device is output. For example, if an X-ray film is currently taken on a breast patient, the second image x2 is selected to be output.

Further, the imaging method further includes:

A processor is used to perform image arithmetic processing on the first image x1 and the second image x2 to obtain a synthesized combined image f(x1)+f(x2). For example, the current imaging of thicker but low-density tissues, such as the hip joint, requires subtraction of the first image and the second image. After balancing the resolution and quantum detection efficiency, the composite of interest can be output. image. 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 repeated here.

The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

An X-ray detector with dual energy spectrum and dual resolution, which is characterized by comprising a first visible light sensor (1), a first fluorescent material layer (3), a packaging material spacer (5), The second fluorescent material layer (4) and the second visible light sensor (2), the first visible light sensor (1) is closer to the X-ray source than the second visible light sensor (2), and the first visible light sensor (1) The resolution 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 (3); The material layer (4) is excited by X-rays to generate visible photons; the packaging material spacer (5) is used to isolate the first fluorescent material layer (3) from the visible photons generated by the X-ray excitation. The two fluorescent material layers (4) are excited by X-rays to generate visible photons.
The dual-energy spectrum dual-resolution X-ray detector according to claim 1, wherein the thickness of the second fluorescent material layer (4) is greater than the thickness of the first fluorescent material layer (3).
The dual-energy spectrum dual-resolution X-ray detector according to claim 1, characterized in that it further comprises a circle arranged along the sides of the first fluorescent material layer (3) and the second fluorescent material layer (4) The packaging material wall layer (6), and one edge of the packaging material wall layer (6) is opposed to the first visible light sensor (1), and the other edge is opposed to the second visible light sensor (2), and the packaging material separates The edge of the layer (5) is opposed to the inner surface of the packaging material wall layer (6).
The dual-energy spectrum dual-resolution X-ray detector according to claim 3, wherein the first visible light sensor (1) and the second visible light sensor (2) have the same shape and size, and the first The 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 that of the first fluorescent material layer (3) and the packaging material wall layer ( 6) It has a recessed structure relative to the first visible light sensor (1) and the second visible light sensor (2).
The dual-energy spectrum dual-resolution X-ray detector according to claim 4, wherein the packaging material spacer (5) and the packaging material wall layer (6) are both made of X-ray fluorescence packaging materials The packaging material is aluminum film and hot melt adhesive.
The dual-energy spectrum dual-resolution X-ray detector according to claim 1, wherein the first fluorescent material layer (3) and the second fluorescent material layer (4) contain X-ray conversion material It is cesium iodide, PbF 2 crystal, NaBi(WO 4 ) 2 crystal, NaI:Tl crystal or CsI:Tl crystal.
A dual-energy spectrum dual-resolution X-ray detection system, characterized in that it comprises an X-ray source, a first image acquisition device, a second image acquisition device, and any one of claims 1 to 6 X-ray detector with dual energy spectrum and dual resolution, the first image acquisition device is electrically connected to the first visible light sensor (1) to acquire the first image, and the second image acquisition device is electrically connected to the second visible light sensor (2). ) Electrically connected to capture the second image.
8. The dual-energy spectrum dual-resolution X-ray detection system according to claim 7, further comprising a processor electrically connected to the first image acquisition device and the second image acquisition device, The processor can perform image operation processing on the first image collected by the first image collecting device and the second image collected by the second image collecting device.
An imaging method based on the dual-energy spectrum dual-resolution X-ray detection system according to claim 7, characterized in that it comprises the following steps:

Turn on the X-ray source to emit X-rays to the first visible light sensor of the X-ray detection system;

If the target obtains a high-resolution image, output the first image collected by the first image collection device;

If the target obtains a high-energy absorption image, the second image collected by the second image collecting device is output.
The imaging method according to claim 9, characterized in that, based on the dual-energy spectrum dual-resolution X-ray detection system according to claim 8, the imaging method further comprises:

A processor is used to perform image arithmetic processing on the first image and the second image to obtain a synthesized combined image.