Energy spectrum imaging system and method

Abstract

The present invention relates to the technical field of X-ray imaging, and provides an energy spectrum imaging system and method, the energy spectrum imaging system comprising: a ray emitting mechanism having a ray emitting end; an imaging receiving mechanism having a ray receiving end, the ray receiving end being arranged opposite to the ray emitting end of the ray emitting mechanism; a filtering mechanism being arranged before the ray receiving end of the imaging receiving mechanism, the filtering mechanism having at least two filtering units, the filtering units being used to separate the rays emitted by the ray emitting mechanism and passing through the object to be detected into rays having at least different energies; the imaging receiving mechanism simultaneously receives the rays separated by the filtering mechanism, and transmits the data to a computing unit. The energy spectrum imaging system can realize dual-energy or multi-energy imaging in one scan, improves detection efficiency, reduces the harm caused by radiation to patients, and does not need to change the internal crystal structure, materials and related manufacturing processes of the existing planar array detector, which is conducive to reducing production costs.

Description

Technical Field

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

[0002] Spectral CT imaging technology can use the different absorption of X-rays of different energies produced by matter to provide more imaging information than conventional CT. It can not only obtain material density and its distribution image, but also obtain spectral images. On this basis, it can calculate the effective atomic coefficients and electron density of lesions or tissues to achieve specific tissue identification. It has great application potential in material identification, bone density measurement, etc.

[0003] In the energy spectrum imaging system of related technologies, when performing energy spectrum CT imaging, the most commonly used method is to use a double-layer energy spectrum detector that can resolve energy. It adopts a conventional CT scanning scheme, collects low-energy and high-energy rays through the upper and lower layers of detectors respectively for energy collection, and then performs relevant energy spectrum calculations. In addition, photon counting detectors are also commonly used. By setting energy gating thresholds, the energy spectrum channels are divided, and the number of photons in different energy spectrum regions is accumulated and counted respectively, so as to obtain more comprehensive energy spectrum information about different materials and realize material identification. However, the above two methods change the internal structure or semiconductor material of the detector, which is costly to implement and has a complex structure. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the energy spectrum imaging systems in the related art that all of them change the internal structure or semiconductor material of the detector, resulting in high cost and complex structure, thereby providing an energy spectrum imaging system and method.

[0005] The present invention provides an energy spectrum imaging system, comprising: a ray emitting mechanism, having a ray emitting end; an imaging receiving mechanism, having a ray receiving end, the ray receiving end being arranged opposite to the ray emitting end of the ray emitting mechanism, and an object to be detected being arranged between the imaging receiving mechanism and the ray emitting mechanism; a filtering mechanism, arranged before the ray receiving end of the imaging receiving mechanism, the filtering mechanism having at least two filtering units arranged in parallel, the filtering units being used to separate the rays emitted by the ray emitting mechanism and passing through the object to be detected into rays with at least two different energies; the imaging receiving mechanism simultaneously receives the rays separated by the filtering mechanism, and transmits the data to a computing unit.

[0006] Optionally, the filtering mechanism comprises: a ray filter, the ray filter having a filtering unit array for separating the rays, and the filtering unit array having at least two types of filtering units.

[0007] Optionally, the two types of filter units are alternately arranged in sequence along the horizontal and vertical directions on the filter unit array.

[0008] Optionally, the filtering unit on the ray filter is square.

[0009] Optionally, among the filter units on the filter unit array, at least one filter unit is a cavity structure.

[0010] Optionally, the filter unit array is a single-layer structure.

[0011] Optionally, the imaging receiving mechanism comprises: a planar array detector having a crystal array for receiving rays, and the crystal units on the crystal array correspond one-to-one to the filtering units on the ray filter.

[0012] Optionally, the shape of the crystal unit on the planar array detector is the same as the shape of the filter unit on the ray filter.

[0013] Optionally, the area of ​​the crystal unit on the planar array detector is smaller than or equal to the area of ​​the filter unit on the ray filter.

[0014] Optionally, both of the two filter units are long strip structures, and the two filter units are arranged along the transverse direction on the filter unit array.

[0015] The present invention also provides an energy spectrum imaging method, comprising the following steps: emitting rays toward an object to be detected by a ray emitting mechanism; after the rays pass through the object to be detected, separating the rays into at least two rays with different energies by a filtering mechanism; irradiating the separated multiple rays on an imaging receiving mechanism at the same time; and transmitting data to a computing unit after receiving the rays with different energies by the imaging receiving mechanism.

[0016] The technical solution of the present invention has the following advantages:

[0017] The energy spectrum imaging system provided by the present invention is provided with a filtering mechanism before the receiving end of the imaging receiving mechanism. When in use, the ray emitting end of the ray emitting mechanism emits X-rays, which pass through the scanned object and then pass through the filtering unit with different transmission capabilities, and then are divided into rays with different energies. The rays with different energies are received by the ray receiving end of the imaging receiving mechanism, and the data is transmitted to the computing unit, and finally a dual-energy or energy spectrum image for the same scanned object can be generated. The energy spectrum imaging system can realize dual-energy or multi-energy imaging in one scan, improves detection efficiency, reduces the harm caused by radiation to patients, and does not need to change the internal crystal structure, materials and related manufacturing processes of the existing planar array detector, which is conducive to reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of an energy spectrum imaging system provided in one embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in one embodiment of the present invention;

[0021] Figure 3 For use Figure 2 Schematic diagram of the data of two rays of different energies obtained by the ray filter in FIG.

[0022] Figure 4 To use interpolation method to process Figure 3 A schematic diagram of the data obtained by the ray filter shown;

[0023] Figure 5 To use interpolation method to process Figure 3 Another schematic diagram of the data obtained by the ray filter shown;

[0024] Figure 6 To use pixel merging processing Figure 4 A schematic diagram of the data in ;

[0025] Figure 7 for Figure 6 Schematic diagram of the processed results;

[0026] Figure 8 A schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in yet another embodiment of the present invention;

[0027] Fig. 9 For use Figure 8 Schematic diagram of the data of four rays with different energies obtained by the ray filter in;

[0028] Fig.10 To use interpolation method to process Fig. 9 A schematic diagram of the data obtained by the ray filter shown;

[0029] Fig.11 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown;

[0030] Fig.12 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown;

[0031] Fig.13 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown;

[0032] Fig.14 To use pixel merging processing Fig.10 A schematic diagram of the data in ;

[0033] Fig.15 for Fig.14 Schematic diagram of the processed results;

[0034] Fig.16 It is a schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in yet another embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1. Ray filter; 2. First filtering unit; 3. Second filtering unit;

[0037] 4. The third filtering unit; 5. The fourth filtering unit. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] Figure 1 FIG. 1 is a schematic diagram of the structure of an energy spectrum imaging system provided in one embodiment of the present invention; Figure 1 As shown, the present invention provides an energy spectrum imaging system, comprising: a ray emitting mechanism, having a ray emitting end; an imaging receiving mechanism, having a ray receiving end, the ray receiving end being arranged opposite to the ray emitting end of the ray emitting mechanism, and an object to be detected being arranged between the imaging receiving mechanism and the ray emitting mechanism; a filtering mechanism, arranged before the ray receiving end of the imaging receiving mechanism, the filtering mechanism having at least two filtering units arranged in parallel, the filtering units being used to separate the rays emitted by the ray emitting mechanism and passing through the object to be detected into rays with at least two different energies; the imaging receiving mechanism simultaneously receives the rays separated by the filtering mechanism, and transmits the data to the computing unit.

[0043] The energy spectrum imaging system provided by the present invention is provided with a filtering mechanism before the receiving end of the imaging receiving mechanism. When in use, the ray emitting end of the ray emitting mechanism emits X-rays, which pass through the scanned object and then pass through the filtering unit with different transmission capabilities, and then are divided into rays with different energies. The rays with different energies are received by the ray receiving end of the imaging receiving mechanism, and the data is transmitted to the computing unit, and finally a dual-energy or energy spectrum image for the same scanned object can be generated. The energy spectrum imaging system can realize dual-energy or multi-energy imaging in one scan, improves detection efficiency, reduces the harm caused by radiation to patients, and does not need to change the internal crystal structure, materials and related manufacturing processes of the existing planar array detector, which is conducive to reducing production costs.

[0044] For example, the energy spectrum imaging system may be a cone beam CT scanning system or a direct digital X-ray photography system.

[0045] For example, the ray emitting mechanism may be a ray generator, and the emitting end of the ray emitting mechanism may emit X-rays for scanning. When scanning is required, the ray emitting mechanism emits rays and may rotate around the object to be detected to perform a 360° scan of the object to be detected. For example, the filtering mechanism may have two filtering units, namely the first filtering unit 2 and the second filtering unit 3. The two filtering units have different transmittances to rays. For example, the transmittance of the first filtering unit 2 to X-rays is higher than that of the second filtering unit 3. Then, the X-rays are converted into high-energy X-rays and low-energy X-rays after passing through the filtering mechanism. For example, the imaging receiving mechanism may be a planar array detector, which is specifically used to receive high-energy X-rays and low-energy X-rays passing through the object to be detected, and the received ray data may be fed back to the computing unit. For example, the computing unit may be a computer, which may generate an image based on the received ray data.

[0046] The filtering mechanism in this embodiment can be used as an independent component and can be arranged before the area array detector to separate the rays into rays with different energies after the rays scan the object to be detected.

[0047] Figure 2 FIG. 1 is a schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in one embodiment of the present invention; Figure 2 As shown, in one embodiment, the filtering mechanism includes: a ray filter 1, the ray filter 1 has a filter unit array for separating rays, and the filter unit array has at least two filter units arranged in parallel.

[0048] For example, the filter unit array may include two filter units, namely, a first filter unit 2 and a second filter unit 3, and the first filter unit 2 and the second filter unit 3 are alternately arranged in sequence along the horizontal and vertical directions on the filter unit array.

[0049] For example, the filtering unit may also include four filtering units, namely, a first filtering unit 2, a second filtering unit 3, a third filtering unit 4 and a fourth filtering unit 5, and the first filtering unit 2, the second filtering unit 3, the third filtering unit 4 and the fourth filtering unit 5 are alternately arranged in a counterclockwise or clockwise direction.

[0050] For example, the filtering unit can also include nine filtering units, namely, a first filtering unit 2, a second filtering unit 3, a third filtering unit 4, a fourth filtering unit 5, a fifth filtering unit, a sixth filtering unit, a seventh filtering unit, an eighth filtering unit and a ninth filtering unit. The nine filtering units can be arranged in an S shape or distributed in different positions as needed.

[0051] In yet another embodiment, the filter unit on the ray filter 1 is square.

[0052] For example, each filtering unit may be square or circular.

[0053] In yet another embodiment, among the filter units on the filter unit array, at least one filter unit is a cavity structure.

[0054] For example, different filter units may correspond to a filter material with a certain transmittance, and the filter material may be aluminum and copper, or air. For example, the transmittance of the same filter material may be changed by changing its thickness.

[0055] In another embodiment, the filter unit array is a single-layer structure. For example, the body of the entire ray filter 1 can be a substrate, for example, the entire substrate is a mesh frame structure, and different filter materials can be embedded in the corresponding mesh area. For example, the substrate is made of a certain filter material, and holes are punched at the required positions on the surface of the substrate to form a hollow area. At this time, the hollow area is another filter material, that is, air. For example, the ray filter 1 also includes a bottom plate, and the substrate is arranged on the surface of the bottom plate. The bottom plate can be used for bonding or welding on the ray emitting mechanism, and the thickness of the bottom plate can be set smaller to reduce the energy attenuation when the X-ray passes through.

[0056] In another embodiment, the imaging receiving mechanism includes: a planar array detector, the planar array detector has a crystal array for receiving rays, and the crystal units on the crystal array correspond to the filter units on the ray filter 1 one by one. For example, the specification of the filter unit can be 64*64, that is, 64 grid areas are set along the length direction of the substrate, and 64 grid areas are set along the width direction of the substrate. When in use, the filter unit on the substrate can be aligned with the crystal array of the planar array detector, which is conducive to improving the imaging effect.

[0057] In yet another embodiment, the shape of the crystal unit on the planar array detector is the same as the shape of the filter unit on the ray filter 1 .

[0058] In yet another embodiment, the area of ​​the crystal unit on the planar array detector is less than or equal to the area of ​​the filter unit on the ray filter 1 .

[0059] For example, when the area of ​​the filter unit is the same as the area of ​​the crystal unit of the planar array detector, one crystal unit can correspond to one filter unit. For example, when the area of ​​the filter unit is larger than the size of the crystal unit of the planar array detector, one filter unit can correspond to multiple crystal units.

[0060] In yet another embodiment, the filtering mechanism may be packaged inside the area array detector. After the rays enter the area array detector, they are separated into rays with different energies and then reach the crystal unit of the area array detector.

[0061] In yet another embodiment, the filtering mechanism may be attached to the outer surface of the area array detector. Before the rays enter the area array detector, they are separated into rays with different energies and then reach the crystal unit of the area array detector.

[0062] The present invention also provides an energy spectrum imaging method, comprising the following steps: emitting rays toward an object to be detected by a ray emitting mechanism; after the rays pass through the object to be detected, separating the rays into at least two rays with different energies by a filtering mechanism; irradiating the separated multiple rays on an imaging receiving mechanism at the same time; and transmitting data to a computing unit after receiving the rays with different energies by the imaging receiving mechanism.

[0063] Take the case where there are two types of filter units on the filter unit array as an example. Figure 3 For use Figure 2 Schematic diagram of the data of two rays of different energies obtained by the ray filter in FIG. Figure 4 To use interpolation method to process Figure 3 A schematic diagram of the data obtained by the ray filter shown; Figure 5 To use interpolation method to process Figure 3 Another schematic diagram of the data obtained by the ray filter shown; Figure 6 To use pixel merging processing Figure 4 A schematic diagram of the data in ; Figure 7 for Figure 6 Schematic diagram of the result after processing in the figure; wherein, "A" in each figure represents data obtained by a ray of one energy, "B" represents data obtained by another ray of one energy, "C" represents data obtained by another ray of one energy, and "D" represents data obtained by another ray of one energy. That is, A, B, C and D each correspond to data obtained by a ray of one energy.

[0064] like Figure 3 As shown, in one scan, the ray generator uses a high voltage, such as 110KV, to emit a beam. After the X-rays are filtered by the ray filter 1, they pass through the object to be detected, and then reach the receiving end of the array detector, and are finally fed back to the calculation unit for imaging. Among them, the X-ray data passing through the first filter unit with high X-ray transmittance is high-energy data, and the X-ray data passing through the second filter unit 3 with low X-ray transmittance is low-energy data. After data extraction, reconstruction can be performed to obtain two sets of projection images of high-energy data and low-energy data for the same object, thereby realizing projection acquisition of dual-energy imaging.

[0065] For example, in one embodiment, the data marked with "*" is supplemented by interpolation, such as Figure 4 and Figure 5 As shown, two sets of data with the same number of original samples are obtained. After that, the pixel merging method is adopted, as shown in Figure 6 As shown, high energy data and low energy data are obtained, and the number of samples is reduced to 1 / 2 of the original, as shown in Figure 7 Finally, the linear attenuation coefficient of the scanned object under two energies is obtained by reconstruction, and then different base materials are selected to perform base material decomposition calculations on the detected object, thereby obtaining the atomic number image and electron density image to achieve the identification of specific tissues.

[0066] Take the case where there are two types of filter units on the filter unit array as an example. Figure 8 A schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in yet another embodiment of the present invention; Fig. 9 For use Figure 8 Schematic diagram of the data of four rays with different energies obtained by the ray filter in; Fig.10 To use interpolation method to process Fig. 9 A schematic diagram of the data obtained by the ray filter shown; Fig.11 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown; Fig.12 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown; Fig.13 To use interpolation method to process Fig. 9 Another schematic diagram of the data obtained by the ray filter shown; Fig.14 To use pixel merging processing Fig.10 A schematic diagram of the data in ; Fig.15 for Fig.14 Schematic diagram of the processed results. Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14 as well as Fig.15 As shown, in another embodiment, the ray filter 1 further includes a plurality of third filter units 4 and a fourth filter unit 5, and the first filter unit 2, the second filter unit 3, the third filter unit 4 and the fourth filter unit 5 are alternately arranged in a counterclockwise or clockwise direction. Among them, the four filter units form a small whole, and the distribution positions of the first filter unit 2, the second filter unit 3, the third filter unit 4 and the fourth filter unit 5 in the small whole can be designed as needed, which is not limited here. The use method of the ray filter 1 containing four filter units is the same as the use method of the ray filter 1 containing two filter units, which will not be repeated here.

[0067] Fig.16 FIG. 1 is a schematic diagram of the structure of a ray filter in an energy spectrum imaging system provided in another embodiment of the present invention. Fig.16 As shown, for example, the energy spectrum imaging system can be a panoramic CT scanning system or a direct digital X-ray photography system.

[0068] In this embodiment, both filter units are long strip structures, which are respectively denoted as the first filter unit 2 and the second filter unit 3 . The first filter unit 2 and the second filter unit 3 are arranged on the substrate along the horizontal direction.

[0069] For example, the size of the ray filter can be designed to be larger. When the ray filter is used, it can be placed at the receiving end of the array detector and completely cover the surface of the detector. After the ray is emitted, it passes through the scanned object, and then passes through the first filter unit 2 as a high-energy ray, and passes through the second filter unit 3 as a low-energy ray. The two types of rays are then received by the array detector, and the array detector feeds back the received ray data to the calculation unit of the energy spectrum imaging system, and finally a dual-energy image can be generated. In addition, the ray generator can be rotated to scan and image different positions of the scanned object.

[0070] In summary, the energy spectrum imaging method can achieve dual-energy or even multi-energy imaging in a single scan, which improves detection efficiency, reduces the harm of radiation to patients, and does not require changes to the internal crystal structure, materials, and related manufacturing processes of existing area array detectors, which is conducive to reducing costs.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A spectrum imaging system, characterized in that: include: A ray emitting mechanism having a ray emitting end; An imaging receiving mechanism, comprising a ray receiving end, the ray receiving end being arranged opposite to the ray emitting end of the ray emitting mechanism, and an object to be detected being arranged between the imaging receiving mechanism and the ray emitting mechanism; A filtering mechanism is arranged before the ray receiving end of the imaging receiving mechanism, and the filtering mechanism has at least two filter units arranged in parallel, and the filter units are used to separate the rays emitted by the ray emitting mechanism and passing through the object to be detected into rays with at least two different energies; The imaging receiving mechanism simultaneously receives the rays separated by the filtering mechanism and transmits the data to the computing unit; The filtering mechanism comprises: a ray filter, the ray filter having a filter unit array for separating the rays, the filter unit array having at least two filter units arranged in parallel; The two types of filter units are alternately arranged in the horizontal and vertical directions on the filter unit array; The filtering unit on the ray filter is square.

2. The energy spectrum imaging system according to claim 1, characterized in that: Among the filter units on the filter unit array, at least one filter unit is a cavity structure.

3. The energy spectrum imaging system according to claim 1, characterized in that: The filter unit array is a single-layer structure.

4. The energy spectrum imaging system according to any one of claims 1 to 3, characterized in that: The imaging receiving mechanism comprises: a planar array detector having a crystal array for receiving rays, and the crystal units on the crystal array correspond one to one with the filter units on the ray filter.

5. The energy spectrum imaging system according to claim 4, characterized in that: The shape of the crystal unit on the planar array detector is the same as the shape of the filter unit on the ray filter; The area of ​​the crystal unit on the planar array detector is smaller than or equal to the area of ​​the filter unit on the ray filter.

6. The energy spectrum imaging system according to claim 1, characterized in that: Both of the two filter units are long strip structures, and the two filter units are arranged along the horizontal direction on the filter unit array.

7. A spectrum imaging method, characterized in that: The energy spectrum imaging system according to any one of claims 1 to 6 comprises the following steps: The ray is emitted toward the object to be detected by a ray emitting mechanism; After the rays pass through the object to be detected, the rays are separated into at least two rays with different energies by a filtering mechanism; The separated multiple rays are irradiated on the imaging receiving mechanism at the same time; After receiving the radiation with different energies through the imaging receiving mechanism, the data is transmitted to the computing unit.

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