Digital detector, device, system, method, apparatus, and computer storage medium

Abstract

The application provides a digital detector, device, system, method, equipment and computer storage medium, the digital detector comprises a scintillation crystal, a collimator and a photoelectric conversion device, the scintillation crystal is a sheet-shaped continuous scintillation crystal and is configured to convert rays into visible light; the collimator is configured to be matched with the scintillation crystal in a sheet shape, and is configured to collimate the visible light converted by the scintillation crystal; the collimator makes the visible light pass through at a preset angle through microchannels; and the photoelectric conversion device is coupled with the collimator and converts the collimated visible light into a flicker pulse signal. The technical scheme of the application can further reduce the size of the photoelectric conversion device, reduce optical crosstalk, and be beneficial to improving the imaging spatial resolution.

Description

Technical Field

[0001] This application relates to the field of high-energy ray detection technology, specifically to a digital detector, device, system, method, equipment, and computer storage medium. Background Technology

[0002] In a range of applications involving high-energy radiation, X-rays, gamma rays, neutron rays, proton rays, and beta rays are commonly used to detect and image the target object. Corresponding imaging equipment includes CT scanners, security screening equipment, PET scanners, and PET-CT scanners. These devices can acquire information such as the number of targets, their internal structure, and / or biochemical information. For example, in radiation detection equipment, detectors convert high-energy radiation into scintillation pulse signals. By sampling and processing these signals, information such as pulse counts, pulse energy, or pulse location can be obtained, which is then converted into images showing the distribution of radiation intensity and dose.

[0003] Existing high-energy X-ray detectors typically include direct-type detectors made of semiconductor materials and indirect-type detectors made by integrating materials. Regarding direct-type detectors made of semiconductor materials, taking CT systems as an example, most major international CT manufacturers are currently focusing on photon counting based on direct-type detectors made of semiconductor materials. In the field of micro-CT equipment, there are also corresponding products for photon-counting micro-CT equipment for small animal imaging. Existing photon-counting X-ray detectors are mainly based on semiconductor silicon, cadmium telluride, and cadmium zinc telluride. Although these detectors have excellent X-ray detection performance, cadmium telluride and cadmium zinc telluride detectors still have a series of problems, such as intolerance to high-flux X-rays (flux refers to the energy of a particle per unit time; high-flux X-rays are high-energy X-rays, referring to photon beams with energy greater than 1MV), polarization effects, complex readout circuits, high cost, and the environmental risks posed by cadmium metal, which greatly limit their application. Furthermore, in micro-CT systems using flat-panel detectors, the large number of detector channels (pixels) is particularly significant, and the development of multi-channel readout circuits presents difficulties. Regarding integrating indirect detectors, taking CT systems as an example, current integrating indirect detectors include scintillation crystals and photoelectric conversion devices. High-energy rays are converted into visible light signals by the scintillation crystal, and the visible light signals are further converted into scintillation pulse signals by the photoelectric conversion device. In this process, the imaging spatial resolution has a significant impact on the final image quality, and the current imaging spatial resolution needs improvement. Taking small animal photon-counting multi-energy spectral CT imaging as an example, small animal CT requires the individual photoelectric conversion device to be as small as possible to improve the imaging spatial resolution. In existing detectors, the scintillation crystal and the photoelectric conversion device are coupled one-to-one. Each scintillation crystal requires optical shielding, that is, wrapping a layer of anti-reflective material to prevent optical crosstalk on the outside of the individual crystal. Due to process and strength limitations, individual scintillation crystals cannot be cut to the required sufficiently small size, and the overall size of a single pixel further increases after wrapping with anti-reflective material. Therefore, the size of a single pixel of the detector cannot be made small enough, affecting the imaging spatial resolution and making it unsuitable for small animal micro-CT imaging.

[0004] Therefore, there is an urgent need to propose a detector or detection device to solve at least one of the problems in the prior art.

[0005] The content of the background section only discloses the technology known to the inventors and does not necessarily represent the prior art in this field. Summary of the Invention

[0006] This application aims to provide a digital detector, apparatus, system, method, device, and computer storage medium to solve at least one of the problems.

[0007] According to a first aspect of this application, a digital detector is provided, the digital detector comprising: a scintillation crystal, the scintillation crystal being a sheet-like continuous scintillation crystal and configured to convert X-rays into visible light; a collimator configured as a sheet matching the scintillation crystal and configured to collimate the visible light converted by the scintillation crystal; the collimator allowing the visible light to pass through at a preset angle via a microchannel; and a photoelectric conversion device coupled to the collimator and converting the collimated visible light into a scintillation pulse signal.

[0008] Optionally, the thickness ratio of the scintillation crystal to the collimator is 1:3 to 1:5.

[0009] Optionally, the thickness of the scintillation crystal is between 1 and 2 mm.

[0010] Optionally, silicone grease is provided between the scintillation crystal and the collimator, and / or silicone grease is provided between the collimator and the photoelectric conversion device.

[0011] Optionally, the cross-sectional shape of the microchannel of the collimator includes a circle, an ellipse, a polygon, and a triangle.

[0012] Optionally, the ratio of the thickness of the collimator to the maximum dimension of the microchannel cross-sectional shape is 8:1 to 10:1.

[0013] Optionally, the preset angle refers to the angle between the extension direction of the microchannel and the plane where the scintillation crystal or the photoelectric conversion device is located, or the angle between the extension direction of the microchannel and the plane where the scintillation crystal or the photoelectric conversion device is located is between 85 and 90 degrees.

[0014] Optionally, the cross-sectional area of ​​the microchannel decreases from the side closer to the scintillation crystal to the side closer to the photoelectric conversion device.

[0015] Optionally, the photoelectric conversion device is a silicon photomultiplier tube.

[0016] According to a second aspect of this application, a digital detection device is provided, comprising: a digital detector as described in any embodiment of this application; and a multi-voltage threshold digital readout acquisition card, configured to digitally acquire a scintillation pulse signal and obtain amplitude information of the scintillation pulse signal, and classify and count the scintillation pulse signal according to the energy range corresponding to the amplitude information of the scintillation pulse signal.

[0017] Optionally, the multi-voltage threshold digital readout acquisition card is equipped with a multi-voltage threshold digital readout circuit, and at least one energy range is preset in the multi-voltage threshold digital readout circuit.

[0018] Optionally, the multi-voltage threshold digital readout circuit includes multiple readout channels, each of which includes multiple comparators configured to preset multiple thresholds corresponding to the amplitude information of the flash pulse signal, with adjacent thresholds forming a threshold interval, and the threshold interval corresponding to different energy ranges.

[0019] Optionally, each readout channel further includes a plurality of counting elements, each of which corresponds one-to-one with a plurality of comparators, and the plurality of counting elements are configured to classify and count the flashing pulse signal according to the energy range corresponding to the amplitude information of the flashing pulse signal.

[0020] Optionally, the comparator is a chip of a multi-voltage threshold digital readout acquisition card with multiple low-voltage differential signal input ports.

[0021] According to a third aspect of this application, a digital detection system is provided, comprising: a digital detection device as described in any embodiment of this application; and a radiation generating device configured to emit radiation toward the digital detection device.

[0022] Optionally, the digital detection system further includes: a data transmission industrial control computer configured to communicate with the digital detection device to receive detection data from the digital detector; and an image reconstruction industrial control computer configured to communicate with the data transmission industrial control computer to receive the detection data and perform image reconstruction.

[0023] Optionally, the digital detection system further includes a motion control bed, which drives the object under test to move between the X-ray generating device and the digital detection device during detection.

[0024] Optionally, the digital detection system also includes a replaceable power supply.

[0025] Optionally, the replaceable power source is a modular combination battery.

[0026] Optionally, the digital detection system further includes a rotating element, and the ray generating device, the digital detection device, the replaceable power supply, the data transmission industrial control computer, and the image reconstruction industrial control computer are arranged in a polygonal pattern on the rotating element.

[0027] Optionally, the rotating element is provided with an opening, and the motion control bed can be moved into the opening.

[0028] Optionally, the digital detection system further includes a grating element configured to monitor the rotation angle signal of the rotating element and feed it back to the data transmission industrial control computer.

[0029] According to a fourth aspect of this application, a digital detection method is provided, comprising: acquiring a scintillation pulse signal using a digital detector according to any embodiment of this application; digitally acquiring the scintillation pulse signal using a multi-voltage threshold digital readout acquisition card and acquiring amplitude information of the scintillation pulse signal; and determining a corresponding energy range based on the amplitude information of the scintillation pulse signal to classify and count the scintillation pulse signal.

[0030] Optionally, using a multi-voltage threshold digital readout acquisition card to digitally acquire the flicker pulse signal and obtain the amplitude information of the flicker pulse signal includes the following steps: multiple thresholds are preset in the multi-voltage threshold digital readout acquisition card, with adjacent thresholds forming a threshold interval, and the amplitude information of the flicker pulse signal falling into the corresponding threshold interval; the amplitude of the flicker pulse signal is compared with the preset multiple thresholds, and the threshold interval corresponding to the amplitude of the flicker pulse signal is determined based on the highest threshold crossed by the flicker pulse signal.

[0031] Optionally, multiple thresholds are preset in the multi-voltage threshold digital readout acquisition card, and the comparison between the amplitude of the flashing pulse signal and the preset multiple thresholds is implemented using the comparator of the multi-voltage threshold digital readout acquisition card.

[0032] Optionally, the digital detection method further includes: reading the scintillation pulse signal classification and counting information through a multi-voltage threshold digital readout circuit configured in the multi-voltage threshold digital readout acquisition card, wherein the multi-voltage threshold digital readout circuit includes multiple digital readout channels, and each readout channel includes multiple comparators.

[0033] Optionally, multiple low-voltage differential signal input ports of the chip of the multi-voltage threshold digital readout acquisition card are used as the comparator.

[0034] Optionally, the energy range is preset in the multi-voltage threshold digital readout acquisition card according to the energy of the photon, and the energy range corresponds to the threshold range.

[0035] Optionally, the step of determining the corresponding energy range based on the amplitude information to classify and count the flicker pulse signal includes: determining the energy range corresponding to the flicker pulse signal based on the threshold range into which the amplitude of the flicker pulse signal falls, and classifying and counting the flicker pulse signal according to the different energy ranges into which it falls.

[0036] Optionally, the counting of the flickering pulse signals according to the different energy ranges they fall into is achieved using a counting element.

[0037] Optionally, the counting element is implemented through multiple digital readout channels of the multi-voltage threshold digital readout circuit configured in the multi-voltage threshold digital readout acquisition card.

[0038] Optionally, the flicker pulse signal is digitally acquired using a multi-voltage threshold digital readout acquisition card, and the amplitude information of the flicker pulse signal is obtained. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal. This is achieved using a multi-voltage threshold digital readout circuit configured inside the multi-voltage threshold digital readout acquisition card.

[0039] According to a fifth aspect of this application, a multi-energy spectral CT imaging method is provided, comprising: performing a rapid pre-scan using an image reconstruction industrial control computer to adjust a motion control bed to a scanning position matching an X-ray generator; the image reconstruction industrial control computer activating the X-ray generator via a data transmission industrial control computer; using a digital detection device as described in any embodiment of this application to count the X-ray sub-energy intervals after attenuation by the object under test to generate projection data; and the data transmission industrial control computer receiving the projection data and transmitting the projection data to the image reconstruction industrial control computer for image reconstruction.

[0040] Optionally, a replaceable power supply is used to power the image reconstruction industrial control computer, the motion control bed, the X-ray generating device, the data transmission industrial control computer, and the digital detection device.

[0041] Optionally, the replaceable power source is a modular combination battery.

[0042] Optionally, a digital detection device is used to count the X-rays after they have attenuated through the object under test in different energy ranges to generate projection data. This includes: using the digital detection device to detect the X-rays to obtain scintillation pulse signals; using a multi-voltage threshold digital readout acquisition card to digitally acquire the scintillation pulse signals and obtain the amplitude information of the scintillation pulse signals; determining the corresponding energy ranges based on the amplitude information of the scintillation pulse signals to classify and count the scintillation pulse signals to generate projection data.

[0043] Optionally, a multi-voltage threshold digital readout acquisition card is used to digitally acquire the flicker pulse signal and obtain the amplitude information of the flicker pulse signal. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal. This is achieved using a multi-voltage threshold digital readout circuit configured therein.

[0044] Optionally, within the multi-voltage threshold digital readout circuit, an energy range is preset based on the photon energy, and the energy range corresponds to the threshold range. The multi-voltage threshold digital readout circuit includes multiple digital readout channels, each of which includes multiple comparators and counting elements corresponding to each comparator. Multiple thresholds are preset using the multiple comparators, and the amplitude of the flicker pulse signal is compared with the preset multiple thresholds to obtain the highest threshold reached by the flicker pulse signal, thereby determining the threshold range corresponding to the amplitude of the flicker pulse signal. The energy range corresponding to the flicker pulse signal is determined based on the threshold range corresponding to the amplitude of the flicker pulse signal, and the multiple counting elements are used to classify and count the flicker pulse signal according to the energy range.

[0045] Optionally, the comparator is a chip of a multi-voltage threshold digital readout acquisition card with multiple low-voltage differential signal input ports.

[0046] According to a sixth aspect of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to perform the digital detection method described in any embodiment of this application when running the computer program.

[0047] According to a seventh aspect of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to perform the multi-energy spectral CT imaging method according to any embodiment of this application when running the computer program.

[0048] According to an eighth aspect of this application, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the digital detection method described in any embodiment of this application.

[0049] According to a ninth aspect of this application, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the multi-energy spectral CT imaging method described in any embodiment of this application.

[0050] Based on the aforementioned digital detectors, devices, systems, methods, equipment, and computer storage media, this application designs a scintillation crystal, a collimator, and a photoelectric conversion device, enabling the detector pixel size to be determined by the minimum size of the photoelectric conversion device, further reducing the size of the photoelectric conversion device and improving resolution. By using the collimator to select the visible light converted by the scintillation crystal, visible light at a certain angle can be incident on the photoelectric conversion device through its microchannel, reducing optical crosstalk. This eliminates the need for an anti-reflective material to wrap the scintillation crystal, effectively utilizing its detection area.

[0051] To further understand the features and technical content of this application, please refer to the following detailed description and drawings of this application. However, this description and drawings are only used to illustrate this application and are not intended to limit the scope of protection of this application in any way. Attached Figure Description

[0052] This application will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0053] Figure 1 An explosion schematic diagram of a digital detector according to an example embodiment of this application is shown;

[0054] Figure 2 Showing according to Figure 1 A side view of the digital detector in the embodiment;

[0055] Figure 3 Showing according to Figure 1 A partial enlarged view of the digital detector in the embodiment;

[0056] Figure 4 An exploded schematic diagram of a digital detection device according to an example embodiment of this application is shown;

[0057] Figure 5 Showing according to Figure 4 Side view of the digital detection device in the embodiment;

[0058] Figure 6 An exploded schematic diagram of an array digital detection device according to an example embodiment of this application is shown;

[0059] Figure 7 A flowchart illustrating a digital detection method according to an example embodiment of this application is shown;

[0060] Figure 8 A side view of a CT imaging apparatus according to an example embodiment of this application is shown;

[0061] Figure 9 A front view of a CT imaging apparatus according to an example embodiment of this application is shown. Detailed Implementation

[0062] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "on top of," and "over" the second feature includes the first feature being located directly above or diagonally above the second feature, or simply indicates that the height of the first feature is greater than that of the second feature in a certain dimensional direction. "Below," "below," and "under" the second feature includes the first feature being located directly above or diagonally above the second feature, or simply indicates that the height of the first feature is less than that of the second feature in a certain dimensional direction.

[0066] The following disclosure provides many different embodiments or examples to describe different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals may be repeated in different examples; this repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0067] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this application.

[0068] Figure 1 A schematic diagram of the exploded structure of a digital detector 100 according to an example embodiment of this application is shown. Figure 2 Showing according to Figure 1 A side view of the digital detector 100 in this embodiment. Figure 1 Combination Figure 2 As can be seen from the example embodiments of this application, the digital detector 100 disclosed in this application includes at least: a scintillation crystal 110, which is a continuous scintillation crystal and is constructed in a sheet shape, the scintillation crystal 110 being configured to convert X-rays into visible light; a collimator 120, which is constructed in a sheet shape matching the scintillation crystal 110 and coupled to the scintillation crystal 110, the collimator 120 having microchannels extending along the thickness direction of the scintillation crystal 110 or the collimator 120 or in a direction connecting the scintillation crystal 110 and the photoelectric conversion device array 130, the collimator 120 being configured to collimate the visible light converted by the scintillation crystal 110; and a photoelectric conversion device array 130, which is coupled to the collimator 120 to convert the collimated visible light into scintillation pulse signals.

[0069] In some embodiments, the radiation includes X-rays, gamma rays, and high-energy radiation such as neutron rays, proton rays, and beta rays, but is not limited to the above types of radiation.

[0070] In some embodiments, the "sheet-like" shape of the scintillation crystal 110 can specifically refer to a dimension in two of the three dimensions being significantly larger than the dimension in the third dimension. For example, when the scintillation crystal is formed as a cuboid sheet, its length and width dimensions are larger than its thickness dimension, such as a length of 5 mm, a width of 4 mm, and a thickness of only 0.5 mm. Similarly, when the scintillation crystal is formed as a circular or elliptical sheet, its radius or its major and minor axes dimensions are significantly larger than its thickness dimension, such as a radius of 5 mm, a major axis of 5 mm, a minor axis of 4 mm, and a thickness of only 0.5 mm. Preferably, the smaller dimension of the scintillation crystal 110, for example, its thickness, is preferably 1–2 mm. This thickness allows the scintillation crystal to have higher light conversion efficiency, thereby improving its detection sensitivity. The dimensions of the scintillation crystal 110 in the two larger dimensions, such as length and width, are matched with the array size of the photoelectric conversion devices 130. For example, taking a single photoelectric conversion device 130 with dimensions of 4mm × 4mm × 0.65mm as an example, when the spacing between adjacent photoelectric conversion devices 130 is the same, the length and width dimensions of the scintillation crystal 110 using an 8×6 photoelectric conversion device array are twice that of a 4×3 photoelectric conversion device array. In a preferred embodiment, the scintillation crystal 110 of this application uses a yttrium silicate (YSO) crystal with low background radiation, but is not limited to this. Using the scintillation crystal 110 instead of a semiconductor overcomes the problem of the photosensitive element of a photon counting detector based on semiconductor materials being intolerant to high-flux radiation.

[0071] In some embodiments, the collimator 120 selects visible light at a preset angle to be incident on the photoelectric conversion device 130 through its microchannel to reduce optical crosstalk. The "sheet-like" shape of the collimator 120 can specifically refer to a shape in which the dimensions in two of the three dimensions are significantly larger than the dimension in the third dimension. For example, when the collimator 120 is formed as a cuboid sheet, its length and width dimensions are larger than its thickness dimension, such as a length of 5 mm, a width of 4 mm, and a thickness of only 0.5 mm. Similarly, when the collimator 120 is formed as a circular or elliptical sheet, its radius or its major and minor axes dimensions are significantly larger than its thickness dimension, such as a radius of 5 mm, a major axis of 5 mm, a minor axis of 4 mm, and a thickness of only 0.5 mm. Preferably, the smaller dimension of the collimator 120, such as its thickness, can be at least equal to and no more than five times the thickness of the scintillation crystal 110. This thickness allows the collimator 120 to improve the collimation effect on visible light while reducing light loss. In a preferred embodiment, the thickness ratio of the scintillation crystal 110 to the collimator 120 along the radiation direction or the light propagation direction is 1:3 to 1:5, thereby further reducing optical crosstalk.

[0072] Those skilled in the art should understand that the "preset angle" mentioned above can mean that the extension direction of the microchannel is perpendicular to the plane where the scintillation crystal or photoelectric conversion device is located; or that the extension direction of the microchannel has a certain angle with the plane where the scintillation crystal or photoelectric conversion device is located, such as an angle of 85 to 90 degrees, that is, the extension direction of the microchannel is slightly inclined; or that the cross-sectional area of ​​the microchannel is larger on the side closer to the scintillation crystal and smaller on the side closer to the photoelectric conversion device, and the cross-sectional area of ​​the microchannel decreases from the side closer to the scintillation crystal to the side closer to the photoelectric conversion device. Preferably, the cross-sectional area of ​​the microchannel decreases uniformly from the side closer to the scintillation crystal to the side closer to the photoelectric conversion device. All of the above-mentioned different microchannel configurations can reduce optical crosstalk to varying degrees.

[0073] In a preferred embodiment, the cross-sectional shape of the microchannel 1210 of the collimator 120 includes circular, elliptical, polygonal, and triangular shapes, but is not limited to these shapes. Figure 3 As shown, when the microchannel 1210 within the collimator 120 is a circular aperture, the ratio of the thickness of the collimator 120 to the diameter of the microchannel is 8:1 to 10:1, thereby further improving the effect of reducing optical crosstalk. When the microchannel 1210 within the collimator 120 is an elliptical aperture, the ratio of the thickness of the collimator 120 to the major axis of the microchannel is 8:1 to 10:1, further improving the effect of reducing optical crosstalk. When the microchannel 1210 within the collimator 120 is a triangular aperture, the ratio of the thickness of the collimator 120 to the inner diameter of the microchannel is 8:1 to 10:1, further improving the effect of reducing optical crosstalk. Furthermore, visible light can be filtered out by collimator 120 from visible light photons that enter the photoelectric conversion device 130 at a large tilt angle. That is, visible light photons at a certain angle are selected to enter the photoelectric conversion device 130 through the microchannel of collimator 120. Preferably, visible light with an angle between 0 and arctan(1 / 8) degrees is selected to enter the photoelectric conversion device (such as SiPM) through its microchannel to reduce optical crosstalk. This angle is referenced to the extension direction of the microchannel.

[0074] In one embodiment, the photoelectric conversion device 130 of the digital detector is a silicon photomultiplier tube (SiPM). A scintillation crystal 110 is coupled one-to-one with a collimator 120 and coupled to a SiPM array to form a scintillation crystal / collimator / SiPM digital detector, such that the pixel size of the digital detector is determined by the minimum size of the SiPM. The size of a single SiPM can be 200 μm, or even smaller if process conditions permit. Using a digital detector with smaller pixel sizes, combined with adjustable amplification ratios, enables higher resolution CT imaging for small animals. Simultaneously, the use of SiPMs offers advantages in sensitivity, gain, and dynamic range, allowing for the detection of lower light intensities and even single-photon counting, making it particularly suitable for low-dose and ultra-low-dose CT imaging.

[0075] In one embodiment, silicone grease is provided between the scintillation crystal 110 and the collimator 120, and between the collimator 120 and the photoelectric conversion device 130, so that visible light can be better incident on the silicon photomultiplier tube.

[0076] In the embodiments of this application, the flashing pulse signal includes, but is not limited to, electrical signals (such as voltage signals, current signals, etc.) and acoustic signals.

[0077] Furthermore, the digital detector 100 of this application employs an array coupling method of scintillation crystal 110, collimator 120, and photoelectric conversion device 130, so that the detector pixel size is determined by the minimum size of photoelectric conversion device 130. At this time, a single photoelectric conversion device 130 can meet the required small size, thereby improving the resolution. Moreover, the visible light converted from X-rays by scintillation crystal 110 is collimated by collimator 120 to reduce optical crosstalk, and then reaches photoelectric conversion device 130 to be converted into current pulse signal. Specifically, the visible light is selected by collimator 120 to enter photoelectric conversion device 130 at a certain angle through its microchannel to reduce optical crosstalk, so that the scintillation crystal does not need to be wrapped with anti-reflective material, and the detection area of ​​the scintillation crystal can be effectively utilized. This application adds a collimator 120 between a sheet-like (or planar) continuous scintillation crystal 110 and a photoelectric conversion device 130 to filter out visible light photons that enter the photoelectric conversion device at a large tilt angle. That is, visible light photons at a certain angle are selected to enter the photoelectric conversion device through the microchannel of the collimator, thereby reducing optical crosstalk.

[0078] In a preferred embodiment, the digital detector 100 of this application is a multi-row planar array digital detector comprising multiple planar array detectors. Currently, cone-beam CT is widely used in small animals, and cone-beam CT generally employs flat-panel detectors. However, the planar arrays of detectors in existing small animal photon-counting multi-energy spectral CT imaging systems cannot be made very large (only one or a few rows), which to some extent limits the application of cone-beam CT. This application uses a multi-row planar array detector, which can meet the imaging requirements of cone-beam CT and achieve high-resolution scanning of some key tissues in small animals. Whole-body scans of small animals are completed by switching to helical scanning. Therefore, by employing a multi-row planar array detector, this application can switch between cone-beam and helical scanning schemes, meeting various needs and usage environments for multi-energy spectral CT imaging.

[0079] In one embodiment, the digital detector 100 further includes a multi-voltage threshold (MVT) digital readout acquisition card configured to digitally acquire flicker pulse signals. The MVT digital readout acquisition card includes a chip, specifically an FPGA chip, but is not limited to this; flicker pulse digitization and data aggregation are implemented based on the chip. The chip has a multi-voltage threshold (MVT) digital readout circuit, which includes multiple digital readout channels. Each digital readout channel includes multiple comparators, each corresponding to a signal acquisition channel. The comparators are configured to preset the voltage threshold of their respective acquisition channels. The threshold of each comparator is configured by an independent DAC. For example, multiple thresholds can be set by controlling the DAC through the chip. The flicker pulse signal is input to the comparators to achieve fully digital acquisition. When the amplitude of the flicker pulse signal is greater than the threshold, the comparator outputs a binary value and stores it in a memory unit; when it is not greater than the threshold, the comparator outputs another binary value and stores it in a memory unit, converting the flicker pulse signal into a fully digital electrical signal. A high-precision time-to-digital converter (TDC) in the chip is used to capture the time when the pulse signal exceeds the voltage threshold to obtain the sampling point. By employing an MVT digital readout acquisition card to achieve digital readout, the location, energy, and time information of a single event can be accurately extracted, enabling high-precision signal reconstruction and accurate data acquisition, thereby achieving digital acquisition of flicker pulse signals.

[0080] Preferably, the comparator is a multi-voltage differential signal input port (LVDS) of the chip of the multi-voltage threshold digital readout acquisition card 210.

[0081] like Figures 4-5As shown, one embodiment of this application provides a digital detection device 200, which has at least one energy range divided according to photon energy, including: a digital detector 100 as described in any of the above embodiments of this application; and a multi-voltage threshold (MVT) digital readout acquisition card 210, which is configured to digitally acquire scintillation pulse signals and obtain amplitude information of the scintillation pulse signals, and classify and count the scintillation pulse signals according to the energy range corresponding to the amplitude information of the scintillation pulse signals.

[0082] In one embodiment, the MVT digital readout acquisition card 210 is equipped with a multi-voltage threshold (MVT) digital readout circuit, in which an energy range is preset based on the photon energy. In one embodiment, the preset energy range based on the photon energy in the MVT digital readout circuit is achieved through prior information, for example, by obtaining the correspondence between energy and voltage thresholds through energy correction of the flicker pulse waveform acquired by an oscilloscope. Specifically, the MVT digital readout circuit includes multiple digital readout channels, each digital readout channel including: multiple comparators configured to preset multiple thresholds corresponding to the amplitude of the flicker pulse signal, with adjacent thresholds forming a threshold range, and the threshold range corresponding to different energy ranges; the amplitude information of the flicker pulse signal is the threshold range corresponding to the amplitude of the pulse signal; and multiple counting elements, each corresponding to one of the multiple comparators, and configured to classify and count the flicker pulse signal according to the energy range corresponding to the amplitude information of the flicker pulse signal. For example, three comparators are set in each readout channel. The preset thresholds of these three comparators are 10mV, 40mV, and 80mV, respectively, with corresponding threshold ranges of 10mV~40mV, 40mV~80mV, and greater than 80mV. Prior information is used to obtain the energies corresponding to the three thresholds of 10mV, 40mV, and 80mV as 20keV, 50keV, and 80keV, respectively, with corresponding energy ranges of 20keV~50keV, 50keV~80keV, and greater than 80keV. The counters corresponding to the comparators with thresholds of 10mV, 40mV, and 80mV correspond to energy ranges of 20keV~50keV, 50keV~80keV, and greater than 80keV, respectively. Then, when the amplitude of the flicker pulse signal exceeds the threshold of 10mV but does not exceed the threshold of 40mV, the flicker pulse... The amplitude information of the signal corresponds to a threshold range of 10mV to 40mV, which corresponds to an energy range of 20keV to 50keV. Therefore, the counter of the preset 10mV threshold comparator is incremented by 1. When the amplitude of the flicker pulse signal exceeds the threshold of 40mV but does not exceed the threshold of 80mV, the amplitude information of the flicker pulse signal corresponds to a threshold range of 40mV to 80mV, which corresponds to an energy range of 50keV to 80keV. Therefore, the counter of the preset 40mV threshold comparator is incremented by 1. When the amplitude of the flicker pulse signal exceeds the threshold of 80mV, the amplitude information of the flicker pulse signal corresponds to a threshold range greater than 40mV, which corresponds to an energy range greater than 80keV. Therefore, the counter of the preset 80mV threshold comparator is incremented by 1.

[0083] In one embodiment, the MVT digital readout acquisition card 210 includes a chip, preferably an FPGA chip, but not limited thereto. The MVT digital readout circuit is disposed on the FPGA chip, and the comparator is a plurality of low voltage differential signal input ports (LVDS) of the chip of the multi-voltage threshold digital readout acquisition card 210.

[0084] This embodiment utilizes a dedicated digital readout circuit (MVT) on the MVT digital readout acquisition card 210 to record X-ray photons arriving at the photon counting detection device in pulse form. The amplitude of the recorded pulse is related to the photon energy, and photons of different energies are counted and added to the corresponding energy range. The pulse amplitude corresponds to the energy of the X-ray photon, and the number of pulses corresponds to the number of photons. By setting multiple electronic system thresholds corresponding to the amplitude of the scintillation pulse signal, low-energy pulses can be filtered out, eliminating the influence of low-energy noise on the imaging results. Simultaneously, pulse signals of different amplitudes are identified, their energy information is recognized, and they are accumulated separately into different energy ranges. A wider energy spectrum distribution is counted according to the set energy ranges to obtain imaging information for different energy ranges. Furthermore, the use of the dedicated MVT digital readout acquisition card 210 enables multi-channel measurement, avoiding the use of numerous ADCs and significantly reducing the cost of the photon counting detection device.

[0085] Taking CT systems as an example, current CT systems commonly use integrating indirect detectors, which obtain the total deposited X-ray energy through charge integration over a certain time. The result reflects the average attenuation characteristics of X-rays, losing energy information. The biggest problem with energy integration detectors is the presence of dark current, which leads to a deterioration in the image signal-to-noise ratio at low doses. Therefore, this application employs a photon counting detector, which can divide photons into one or more energy ranges based on their energy and count the photons in each energy range to achieve multi-spectral CT imaging. Furthermore, by setting appropriate thresholds, electronic noise caused by dark current can be eliminated, helping to reduce radiation dose, obtain a higher signal-to-noise ratio, and achieve low-dose CT imaging. Simultaneously, a dedicated multi-voltage threshold digital readout acquisition card enables simultaneous measurement of multiple energy channels.

[0086] Figure 6 The diagram shows an arrangement of a digital detection device array according to one embodiment of this application. Those skilled in the art will understand that the digital detection devices 200 described in any of the above embodiments can be combined into different shapes as needed during actual use, for example... Figure 6 The array consists of four digital detectors 200 arranged along the same plane to form a planar detector array, but the actual combination method is not limited to this. Figure 6As shown, for example, different numbers of digital detection devices 200 can be combined to form a square-shaped detection array, or the digital detection devices 200 can be connected to each other at a certain angle to form part of a polygon. This is something that those skilled in the art can easily conceive of based on the above description, and will not be elaborated further here.

[0087] like Figure 7 As shown, this application also provides a digital detection method, including:

[0088] Step S1: Use a digital detector to acquire the scintillation pulse signal.

[0089] The digital detector described in step S1 can be specifically referred to with respect to the relevant features of the digital detector in any of the above embodiments of this application, and will not be repeated here. In one embodiment, the flashing pulse signal includes, but is not limited to, electrical signals (such as voltage signals, current signals, etc.) and acoustic signals.

[0090] Step S2: Use the multi-voltage threshold digital readout acquisition card 210 to digitally acquire the flicker pulse signal and obtain the amplitude information of the flicker pulse signal. Determine the corresponding energy range based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal.

[0091] In one embodiment, the step S2 of "digitally acquiring the flicker pulse signal using the multi-voltage threshold digital readout acquisition card 210 and obtaining the amplitude information of the flicker pulse signal" includes:

[0092] Step S21: Multiple thresholds are preset in the multi-voltage threshold digital readout acquisition card 210, and the threshold interval is formed between two adjacent thresholds.

[0093] In one embodiment, a threshold interval is formed between two adjacent thresholds of a plurality of thresholds. These thresholds are used to compare with the amplitude of a flickering pulse signal, and the comparison result can be used to determine the threshold interval into which the pulse signal amplitude falls. In one embodiment, the amplitude information of the flickering pulse signal is the threshold interval into which the pulse signal amplitude falls. For example, in each of the multiple readout channels of the multi-voltage threshold digital readout acquisition card 210, four thresholds are preset: 5mV, 40mV, 60mV, and 80mV. The corresponding threshold intervals are 5mV~40mV, 40mV~60mV, 60mV~80mV, and greater than 80mV. Accordingly, determining the threshold interval of the pulse signal amplitude means determining the specific interval into which the pulse signal amplitude falls among the multiple intervals 5mV~40mV, 40mV~60mV, 60mV~80mV, and greater than 80V.

[0094] In one embodiment, multiple thresholds are preset within the multi-voltage threshold (MVT) digital readout acquisition card 210 using comparators. Specifically, the multi-voltage threshold digital readout acquisition card 210 is equipped with a multi-voltage threshold (MVT) digital readout circuit, which includes multiple digital readout channels, each of which includes multiple comparators. In a preferred embodiment, the multi-voltage threshold digital readout acquisition card includes a chip, which may include, but is not limited to, an FPGA. The MVT digital readout circuit is disposed within the chip, and the comparators are multiple low-voltage differential signal input ports (LVDS) of the chip.

[0095] Step S22: Compare the amplitude of the flashing pulse signal with multiple preset thresholds, and obtain the highest threshold reached by the flashing pulse signal to determine the threshold range into which the amplitude of the flashing pulse signal falls.

[0096] In one embodiment, the amplitude of a flicker pulse signal is compared with multiple preset thresholds to determine the threshold range into which the amplitude of the flicker pulse signal falls. This is achieved using comparators in a multi-voltage threshold digital readout acquisition card 210. For example, each readout channel of the multi-voltage threshold digital readout acquisition card 210 has four comparators. Four thresholds are preset using these four comparators: 5mV, 40mV, 60mV, and 80mV. The corresponding threshold ranges are 5mV~40mV, 40mV~60mV, 60mV~80mV, and greater than 80mV. When the amplitude of the flicker pulse signal exceeds the threshold of 5mV but does not exceed the threshold of 40mV, the amplitude information of the flicker pulse signal falls within the 5mV~40mV range. The threshold range of V; when the amplitude of the flicker pulse signal exceeds the threshold of 40mV but does not exceed the threshold of 60mV, the amplitude information of the flicker pulse signal falls within the threshold range of 40mV to 60mV; when the amplitude of the flicker pulse signal exceeds the threshold of 60mV but does not exceed the threshold of 80mV, the amplitude information of the flicker pulse signal falls within the threshold range of 60V to 80mV; when the amplitude of the flicker pulse signal exceeds the threshold of 80mV, the amplitude information of the flicker pulse signal falls within the threshold range greater than 80mV.

[0097] In one embodiment, the step S2 of "determining the corresponding energy range based on amplitude information to classify and count the flicker pulse signals" includes:

[0098] Step S23: Determine the energy range corresponding to the flicker pulse signal based on the threshold range corresponding to the amplitude of the flicker pulse signal, and classify and count the flicker pulse signals according to the energy range.

[0099] In one embodiment, the energy range is preset by the MVT digital readout acquisition card 210 based on the photon energy, and the energy range corresponds to the threshold range. Specifically, the energy range is divided according to the photon energy, and the correspondence between the threshold range of the scintillation pulse signal amplitude and the energy range is obtained through prior information. For example, the correspondence between energy and voltage thresholds is obtained by energy correction of the scintillation pulse waveform acquired by the oscilloscope.

[0100] In a preferred embodiment, the counting of flicker pulse signals according to energy range is achieved using a counting element.

[0101] In one embodiment, each readout channel of the MVT digital readout circuit includes multiple counting elements.

[0102] In another embodiment of this application, step S2, "using a multi-voltage threshold digital readout acquisition card to digitally acquire the flicker pulse signal and obtain the amplitude information of the flicker pulse signal, and determining the corresponding energy range based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal," is implemented using an MVT digital readout circuit configured therein.

[0103] In a preferred embodiment, the multi-voltage threshold (MVT) digital readout acquisition card includes a chip, including but not limited to an FPGA. The chip of the MVT digital readout acquisition card is provided with a multi-voltage threshold (MVT) digital readout circuit. Within the MVT digital readout circuit, an energy range is preset based on the energy of the photons, and the energy range corresponds to a threshold range. The MVT digital readout circuit includes multiple digital readout channels, each of which includes multiple comparators and counting elements corresponding to each comparator. Multiple thresholds are preset using multiple comparators. The amplitude of the flicker pulse signal is compared with the preset thresholds to obtain the highest threshold reached by the flicker pulse signal, thereby determining the threshold range corresponding to the amplitude of the flicker pulse signal. The energy range corresponding to the flicker pulse signal is determined based on the threshold range corresponding to the amplitude of the flicker pulse signal. Multiple counting elements are used to classify and count the flicker pulse signal according to its energy range.

[0104] In one embodiment, the comparator is a plurality of low-voltage differential signal input ports (LVDS) of the chip of the MVT digital readout acquisition card.

[0105] According to another aspect of this application, a digital detection system is provided, comprising: a digital detection device 200 as described in any of the preceding embodiments of this application; and a radiation generator configured to emit radiation toward the detection device. The radiation may include, but is not limited to, X-rays, gamma rays, neutron rays, proton rays, and beta rays. The radiation generator is a device capable of emitting the aforementioned radiations; for example, the radiation generator may be an X-ray tube. Specific radiation generators emitting the corresponding radiations can be found in the prior art and will not be elaborated upon here.

[0106] In one embodiment, the digital detection system further includes an image reconstruction module configured to reconstruct images of digital information acquired by a multi-voltage threshold (MVT) digital readout acquisition card. The structural design of the image reconstruction module can employ existing technologies, and will not be elaborated upon here.

[0107] In one embodiment of this application, the image reconstruction module may include: a data transmission industrial control computer configured to communicate with the digital detection device to receive detection data from the digital detector; and an image reconstruction industrial control computer configured to communicate with the data transmission industrial control computer to receive the detection data and perform image reconstruction. The data transmission industrial control computer may be a computer, a microcontroller, an ARM (AcornRISC Machine processor), or an FPGA (Field-Programmable Gate Array), etc. The data transmission industrial control computer is connected to the photon counting detection device via Camera Link to receive the projection data detected by the digital detection device. The image reconstruction industrial control computer, acting as a host computer, is wirelessly interconnected with the data transmission industrial control computer, and can control the entire system, store data, and perform image processing. In one embodiment, the image reconstruction industrial control computer is a computer, preferably a high-performance industrial computer.

[0108] In one embodiment, the digital detection system further includes a motion control bed 500, which drives the object under test to move between the X-ray generator device and the digital detection device 200 during detection.

[0109] In one embodiment, the digital detection system of this application includes, but is not limited to, […]. Figures 8-9 The multi-energy spectral CT imaging device 10000 is shown. See also... Figures 8-9 The multi-energy spectral CT imaging device 10000 includes: a radiation generating device 400; a digital detection device 200 as described in any of the above embodiments of this application; a data transmission industrial control computer 600, which is configured to communicate with the radiation generating device 400 and the digital detection device 200 to control the radiation generating device 400 and receive detection data from the digital detection device 200; and an image reconstruction industrial control computer 700, which is configured to communicate with the data transmission industrial control computer 600 to receive detection data from the digital detection device 200 and perform image reconstruction.

[0110] In this embodiment, the X-ray generating device 400 is used to emit X-rays to the digital detection device 200, and the X-ray generating device 400 is preferably an X-ray tube.

[0111] Furthermore, in this embodiment, the X-ray generating device 400 is used to emit X-rays to the photon counting and detection device 200. Preferably, an X-ray tube is used as the X-ray generating device, which is heavier and requires more power. After the X-rays are attenuated by the object to be tested (small animal), they reach the photon counting and detection device 200 and are detected by the photon counting and detection device 200 to generate projection data.

[0112] Figures 8-9 The multi-energy spectral CT imaging device 10000 in the illustrated embodiment further includes a motion control bed 500. The motion control bed 500 enables the positioning and movement of the object under test (small animal) during measurement. The motion control bed 500 is driven by a forward / backward motion servo motor 900 and a vertical motion servo motor 800 to achieve forward / backward and vertical movements. The motion control bed 500 is movable and extends into an opening 310 at the center of the motion turntable. The motion control bed 500 drives the object under test to move between the X-ray generating device 400 and the digital detection device 200 during detection.

[0113] In one embodiment, both the data transmission industrial control computer 600 and the image reconstruction industrial control computer 700 are industrial control computers with wireless transmission capabilities. The data transmission industrial control computer 600 and the image reconstruction industrial control computer 700 are lighter than the X-ray tube. The data transmission industrial control computer 600 sends corresponding control signals to the X-ray generator 400 to control the X-ray to be turned on. After the X-rays are attenuated by the object under test (small animal), they are detected by the photon counting detection device 200, generating projection data which is then transmitted to the data transmission industrial control computer 600. The image reconstruction industrial control computer 700 is mounted on the CT stand and has a CT imaging system operating interface with a preset scanning protocol. By adjusting the software in the CT imaging system operating interface, rapid pre-scanning of the object under test, such as a small animal, can be controlled. The image reconstruction industrial control computer 700, mounted on the CT stand, acts as a host computer, wirelessly interconnected with the data transmission industrial control computer 600, and can control the entire system, store data, and perform image processing. The data transmission industrial control computer 600 transmits data to the image reconstruction industrial control computer 700 mounted on the CT scanner bracket. After the scan is completed, the image reconstruction industrial control computer 700 performs reconstruction, post-processing, and visualization based on the received projection data. The specific design of the data transmission industrial control computer 600 and the image reconstruction industrial control computer 700 can be found in the above-described detection system embodiment, and will not be repeated here.

[0114] In one embodiment, the multi-spectral CT imaging system 10000 further includes a replaceable power supply 1200 for providing power to the system.

[0115] This is a modular combination battery. The batteries are customized capacity batteries with different voltage and current outputs to meet the diverse power supply needs of X-ray generators, digital detection devices, and industrial control computers with wireless transmission. Different specifications of batteries can be combined to meet the power requirements of different devices, allowing for reasonable overall weight distribution, convenient and timely power replenishment, and improved scanning efficiency. The modular combination battery system can guarantee the power supply for a certain number of CT scans. Specifically, the modular combination battery includes batteries for powering the X-ray tube, batteries for powering the digital detection device, batteries for powering the data transmission and image reconstruction industrial control computers, and spare batteries of different specifications. The capacity of each battery is related to the component it powers. In one example, the X-ray tube requires the most power, followed by the industrial control computer, and the digital detection device requires the least power. The corresponding battery capacities differ: the battery powering the X-ray tube has the largest capacity and is the heaviest; the battery powering the industrial control computer has the next largest capacity and is of moderate weight; and the battery powering the digital detection device has the smallest capacity and is the lightest.

[0116] In one embodiment, the replaceable power supply 1200 is equipped with a battery power detection system. This system monitors the battery power in real time and communicates with a data transmission industrial control computer, transmitting real-time power information to the computer. The system has a pre-set power level for the CT scan. During the scan, it monitors the battery power in real time. If the current battery power is insufficient to complete the scan, it automatically calculates the missing power and selects a suitable auxiliary battery from the modular battery pack to continue supplying power until the scan is complete. By promptly selecting a suitable backup battery to replenish power, scanning efficiency is improved. In another embodiment, the battery can be charged if the current power is insufficient for a single CT scan.

[0117] In one embodiment, the multi-energy spectral CT imaging system 10000 further includes a rotating element 300. The data transmission industrial control computer 600 has a motion controller to control the rotating element 300. In a preferred embodiment, the rotating element 300 is a motion turntable, but is not limited thereto. In one embodiment, the motion turntable is driven to rotate by a direct-drive servo motor, and the rear end of the motion turntable is connected to the direct-drive servo motor 1000 via a hollow slewing bearing terminal. The motion turntable is used to fix equipment such as the X-ray generating device 400, the digital detection device 200, the replaceable power supply 1200, and the data transmission industrial control computer 600. The data transmission industrial control computer 600 is mounted on the motion turntable, and the motion controller in the data transmission industrial control computer is used to control the motion turntable. The data transmission industrial control computer 600 realizes the control of components on the motion turntable, including motion control of the motion control bed 500, acquisition control of the digital detection device 200, projection data storage and transmission, and real-time monitoring of the battery level of the replaceable power supply 1200.

[0118] In one embodiment, the rotating element 300 is provided with an opening 310. Preferably, the opening 310 is located at the center of the rotating element 300. When a motion turntable is used as the rotating element, the opening 310 is located at the center of the motion turntable. The aperture of the opening 310 is larger than the object to be measured (small animal) and the maximum effective field of view, and is equipped with a position calibration fixture for laser calibration. The rear end of the motion turntable is connected to the direct drive servo motor 1000 through a hollow rotary bearing terminal. The aperture of the opening 310 of the motion turntable is larger than the diameter of the object to be measured (small animal) and the maximum effective field of view. The motion turntable is equipped with a position calibration fixture for laser calibration of the motion control bed. According to one embodiment of the present invention, the motion control bed determines the origin of the calibration coordinates based on laser collimation. One laser beam is set in the center of the X-ray generator and irradiates the center of the detector, while another laser beam is collimated to irradiate the center of the motion turntable. The initial position of the motion control bed is adjusted according to the pre-scanned image to determine the single irradiation range of cone-beam CT and the starting position of spiral CT.

[0119] The heaviest component is the X-ray generator 400, followed by the data transmission industrial control computer 600 with wireless transmission, and the lightest is the digital detection device 200. The X-ray generator 400, digital detection device 200, replaceable power supply 1200, and data transmission industrial control computer 600 are arranged in a polygonal pattern on the rotating element 300 to ensure the stability of the entire rotating turntable's center of gravity. The rotating turntable controls the rotation of the X-ray generator and digital detection device relative to the object under test to collect projection data of the object at different angles.

[0120] In one embodiment, the multi-spectral CT imaging system 10000 further includes a grating element 1100, which is disposed on the rotating element 300 and configured to monitor the rotation angle signal of the rotating element 300 and feed it back to the data transmission industrial control computer 600. In a specific embodiment, the grating element 1100 includes, but is not limited to, a grating ruler. The grating ruler is disposed on the motion turntable and is used to obtain the accurate position of the motion turntable rotation during CT imaging. The grating ruler, along with the X-ray generating device 400, the digital detection device 200, the replaceable power supply 1200, and the data transmission industrial control computer 600, are arranged in a polygonal pattern. The rotation angle signal of the motion turntable is fed back to the data transmission industrial control computer 600 through the grating ruler, so that the digital detection device 200 can record the projection of each angle. After completing the entire 360° scan, the image reconstruction industrial control computer 700 receives the projection data of the full angle and performs reconstruction, post-processing, and visualization. The replaceable power supply 1200 also includes a battery for powering the grating ruler.

[0121] According to an embodiment of the present invention, a storage battery powers all equipment arranged in a polygonal pattern on the rotating turntable, including the X-ray generator, digital detection device, replaceable power supply, data transmission industrial control computer, and grating elements. The battery is rechargeable and replaceable. It is a customized capacity battery with different voltage and current outputs to meet the different power supply requirements of the X-ray generator, digital detection device, and industrial control computer with wireless transmission. This embodiment uses a storage battery to replace the slip ring power supply and can guarantee the power supply for a certain number of CT scans. It is equipped with a battery power detection system that interacts with the industrial control computer with wireless transmission to monitor the battery level in real time. If the battery power is insufficient for a single CT scan, it can be replaced with a fully charged set of matching batteries or left to recharge.

[0122] According to one embodiment of the present invention, the CT system uses lead plates as a shielding shell, and the lead shielding door for changing the object under test also uses lead plates as a shielding shell. The X-ray generator cannot be started if the lead shielding door for the object under test is not closed. In addition, the CT system is designed with a dual-path emergency stop switch to simultaneously and urgently stop the X-ray generator and the servo motor controllers of the direct-drive servo motor, the forward / backward motion servo motor, and the up / down motion servo motor.

[0123] The operation of the multi-energy spectral CT imaging apparatus 10000 according to embodiments of this application will be described next:

[0124] For example, the operation control process of cone-beam small animal photon-counting multi-energy spectral CT imaging for high-resolution local scanning of key tissues in small animals is as follows: After anesthetizing the small animal to be examined, it is fixed on the motion control bed 500, and the lead shielding door of the subject is closed; the CT imaging system operation interface in the image reconstruction industrial control computer 700 with wireless transmission installed on the CT support is opened, and a rapid pre-scan is performed to determine whether the position of the subject (small animal) is suitable. If it is not suitable, it is adjusted through the software in the CT imaging system operation interface until it reaches a suitable position; the scanning protocol is selected, and the scanning command is sent wirelessly to the data transmission industrial control computer 600 installed on the motion turntable; the motion controller in the data transmission industrial control computer 600 controls the motion turntable, and the data transmission industrial control computer 600 sends the corresponding control signals to the X-ray generating device 400. After the X-ray is turned on, it reaches the photon counting digital detection device 200 after being attenuated by the subject, and is detected by the photon counting digital detection device 200 to generate projection data; the rotation angle signal of the motion turntable is fed back to the data transmission industrial control computer 600 through the grating ruler, and the photon counting digital detection device 200 records the projection of each angle. The data transmission industrial computer 600 transmits data to the image reconstruction industrial computer 700. After completing the entire 360° scan, the image reconstruction industrial computer will reconstruct, post-process, and visualize the received full-angle projection data, and finally display it on the image reconstruction industrial computer interface.

[0125] In this embodiment, a spiral CT scan is required for a whole-body scan of a small animal, which is achieved by switching to spiral scanning mode. The operational control flow is as follows:

[0126] After anesthetizing the small animal to be tested, it is fixed to the motion control bed, and the lead shielding door of the test object is closed. The CT imaging system operation interface in the image reconstruction industrial control computer 700 mounted on the CT stand is opened, and a rapid pre-scan is performed to determine whether the initial measurement position of the test object (small animal) is appropriate. If it is not appropriate, it is adjusted through the software in the CT imaging system operation interface until it reaches the appropriate position. The scanning protocol is selected, and the scanning command controls the motion control bed 500. At the same time, it is wirelessly transmitted to the data transmission industrial control computer 600 mounted on the motion turntable. The motion controller in the data transmission industrial control computer 600 controls the motion turntable. The data transmission industrial control computer 600 sends the corresponding control signals to the X-ray generating device 400. After the X-ray is turned on, it reaches the digital detection device 200 after being attenuated by the test object. After being detected by the digital detection device 200, projection data is generated. The rotation angle signal of the motion turntable is fed back to the data transmission industrial control computer 600 through the grating ruler. The digital detection device 200 records the projection of each angle. The data transmission industrial computer 600 transmits data to the image reconstruction industrial computer 700. After completing the entire 360° scan, the image reconstruction industrial computer 700 receives the projection data from all angles, performs reconstruction, post-processing, visualization, and finally displays it on the interface of the image reconstruction industrial computer 700.

[0127] The multi-energy spectral CT imaging device 10000 provided in this application uses a scintillation crystal, collimator, and photoelectric conversion device array coupled to a planar array detector. This allows the detector pixel size to be determined by the minimum size of the photoelectric conversion device, enabling individual photoelectric conversion devices to be used in smaller sizes, thus improving resolution. The collimator selects the visible light converted by the scintillation crystal, allowing visible light at a certain angle to enter the photoelectric conversion device through its microchannel to reduce optical crosstalk. This eliminates the need for anti-reflective material around the scintillation crystal, effectively utilizing its detection area. By employing a multi-row planar array detector, this application allows switching between cone-beam and spiral scanning schemes, meeting various needs and operating environments for multi-energy spectral CT imaging. A replaceable power supply 1200 replaces the slip ring to power the device, resulting in a simple and low-cost multi-energy spectral CT imaging system that can guarantee power supply for a certain number of CT scans. It is equipped with a battery power detection system that interacts with an industrial control computer with wireless transmission, enabling real-time battery monitoring.

[0128] This application also provides a multi-energy spectral CT imaging method, comprising: using an image reconstruction industrial control computer to perform rapid pre-scanning to adjust the motion control bed to a scanning position matching the X-ray generator; the image reconstruction industrial control computer controlling the X-ray generator to start via a data transmission industrial control computer; using the digital detection device of this application embodiment to count the X-ray sub-energy intervals after attenuation by the object under test to generate projection data; and the data transmission industrial control computer receiving the projection data and transmitting it to the image reconstruction industrial control computer for image reconstruction.

[0129] In one embodiment, a replaceable power supply is used to power the image reconstruction industrial control computer, motion control bed, X-ray generator, data transmission industrial control computer, and digital detection device. In a preferred embodiment, the replaceable power supply is a modular combination battery.

[0130] In one embodiment, a digital detection device is used to count the energy ranges of X-rays after attenuation by the object under test to generate projection data. This includes: using the detection device described in any of the above embodiments of this application to detect X-rays to obtain scintillation pulse signals; using a multi-voltage threshold digital readout acquisition card to digitally acquire the scintillation pulse signals and obtain the amplitude information of the scintillation pulse signals; determining the corresponding energy ranges based on the amplitude information of the scintillation pulse signals to classify and count the scintillation pulse signals to generate projection data.

[0131] In one embodiment, a multi-voltage threshold digital readout acquisition card is used to digitally acquire the flicker pulse signal and obtain the amplitude information of the flicker pulse signal. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal. This is achieved using an MVT digital readout circuit configured therein.

[0132] In the embodiments of this application, regarding how the MVT digital readout circuit implements the classification and counting of flicker pulse signals, please refer to the embodiments of the digital detection method described above.

[0133] The apparatus in the embodiments of this application can be combined with the method features in the embodiments of this application, and vice versa.

[0134] This application also relates to computer devices capable of implementing the methods of this application.

[0135] In some embodiments, a computer device is provided, which may include a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor being configured to execute the digital detection method of any embodiment of the present application when running the computer program.

[0136] In some embodiments, a computer device is provided, which may include a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor being configured to execute the spectral CT imaging method of any embodiment of the present application when running the computer program.

[0137] In some embodiments, a computer-readable storage medium is also provided, on which a computer program is stored, configured to be executed to perform any of the digital detection methods or multi-energy spectral CT imaging methods of the present application embodiments. The computer program includes various program modules / units constituting the apparatus according to the embodiments of the present application, and when executed, the computer program composed of the various program modules / units can perform the functions corresponding to the various steps in the methods described in the above embodiments. The computer program can also run on the computer device as described in the embodiments of the present application.

[0138] The storage medium in embodiments of this application includes non-volatile and / or volatile articles that can store information by any method or technology. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0139] Those skilled in the art will understand that the embodiments of this specification can be implemented in various forms, such as methods, systems, or computer program products. Therefore, those skilled in the art will realize that the functional modules / units or controllers and related method steps described in the above embodiments can be implemented in software, hardware, or a combination of software and hardware.

[0140] Unless explicitly stated otherwise, the actions or steps of the methods and procedures described in the embodiments of this application do not necessarily have to be performed in a specific order and can still achieve the desired results. In some implementations, multitasking and parallel processing are also possible or may be advantageous.

[0141] This document describes several embodiments, but for the sake of brevity, the descriptions of the embodiments are not exhaustive, and identical or similar features or parts between the embodiments may be omitted. In this document, "one embodiment," "some embodiments," "example," "specific example," or "some examples" refers to at least one embodiment or example applicable to this application, but not all embodiments. The above terms do not necessarily mean referring to the same embodiment or example. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

[0142] Finally, it should be noted that the above descriptions are merely exemplary embodiments of this disclosure and are not intended to limit this disclosure. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A digital detector, characterized in that, The digital detector includes: A scintillation crystal, wherein the scintillation crystal is a sheet-like continuous scintillation crystal and is configured to convert rays into visible light; A collimator, configured as a sheet to match the scintillation crystal and arranged to collimate the visible light converted by the scintillation crystal; the collimator allows the visible light to pass through at a predetermined angle via a microchannel; and A photoelectric conversion device, which is coupled to the collimator and converts collimated visible light into a scintillation pulse signal.

2. The digital detector according to claim 1, characterized in that, The thickness ratio of the scintillation crystal to the collimator is 1:3 to 1:

5.

3. The digital detector according to claim 1, characterized in that, The thickness of the scintillation crystal is between 1 and 2 mm.

4. The digital detector according to claim 1, characterized in that, Silicon grease is provided between the scintillation crystal and the collimator, and / or silicone grease is provided between the collimator and the photoelectric conversion device.

5. The digital detector according to claim 1, characterized in that, The cross-sectional shape of the microchannel of the collimator includes circular, elliptical, polygonal, and triangular shapes.

6. The digital detector according to claim 5, characterized in that, The ratio of the thickness of the collimator to the maximum dimension of the microchannel cross-sectional shape is 8:1 to 10:

1.

7. The digital detector according to claim 1, characterized in that, The preset angle refers to the extension direction of the microchannel being perpendicular to the plane where the scintillation crystal or the photoelectric conversion device is located, or the angle between the extension direction of the microchannel and the plane where the scintillation crystal or the photoelectric conversion device is located being between 85 and 90 degrees.

8. The digital detector according to claim 1 or 7, characterized in that, The cross-sectional area of ​​the microchannel decreases from the side closer to the scintillation crystal to the side closer to the photoelectric conversion device.

9. The digital detector according to claim 1, characterized in that, The photoelectric conversion device is a silicon photomultiplier tube.

10. A digital detection device, characterized in that, include: The digital detector as described in any one of claims 1-9; as well as A multi-voltage threshold digital readout acquisition card is configured to digitally acquire scintillation pulse signals and obtain amplitude information of the scintillation pulse signals, and classify and count the scintillation pulse signals according to the energy range corresponding to the amplitude information of the scintillation pulse signals.

11. The digital detection device according to claim 10, characterized in that, The multi-voltage threshold digital readout acquisition card is equipped with a multi-voltage threshold digital readout circuit, and at least one energy range is preset in the multi-voltage threshold digital readout circuit.

12. The digital detection device according to claim 11, characterized in that, The multi-voltage threshold digital readout circuit includes multiple readout channels, each of which includes: Multiple comparators are configured to preset multiple thresholds corresponding to the amplitude information of the flash pulse signal, and the threshold intervals between two adjacent thresholds correspond to different energy intervals.

13. The digital detection device according to claim 12, characterized in that, Each readout channel further includes a plurality of counting elements, each of which corresponds one-to-one with a plurality of comparators, and the plurality of counting elements are configured to classify and count the flash pulse signal according to the energy range corresponding to the amplitude information of the flash pulse signal.

14. The digital detection device according to claim 12, characterized in that, The comparator is a chip with multiple low-voltage differential signal input ports of a multi-voltage threshold digital readout acquisition card.

15. A digital detection system, characterized in that, include: The digital detection device as described in any one of claims 10-14; as well as A radiation generating device configured to emit radiation toward the digital detection device.

16. The digital detection system according to claim 15, characterized in that, The digital detection system also includes: A data transmission industrial control computer, configured to communicate with the digital detection device to receive detection data from the digital detector; and An image reconstruction industrial control computer is configured to communicate with the data transmission industrial control computer to receive the detection data and perform image reconstruction.

17. The digital detection system according to claim 16, characterized in that, The digital detection system also includes: A motion control bed drives the object under test to move between the X-ray generating device and the digital detection device during detection.

18. The digital detection system according to claim 17, characterized in that, The digital detection system also includes a replaceable power supply.

19. The digital detection system according to claim 18, characterized in that, The replaceable power source is a modular combination battery.

20. The digital detection system according to claim 18, characterized in that, The digital detection system also includes a rotating element, and the ray generating device, the digital detection device, the replaceable power supply, the data transmission industrial control computer, and the image reconstruction industrial control computer are arranged in a polygonal pattern on the rotating element.

21. The digital detection system according to claim 20, characterized in that, The rotating element has an opening, and the motion control bed can be moved into the opening.

22. The digital detection system according to claim 20, characterized in that, The digital detection system also includes a grating element configured to monitor the rotation angle signal of the rotating element and feed it back to the data transmission industrial control computer.

23. A digital detection method, characterized in that, include: The scintillation pulse signal is acquired using the digital detector as described in any one of claims 1-9; The flicker pulse signal is digitally acquired using a multi-voltage threshold digital readout acquisition card, and the amplitude information of the flicker pulse signal is obtained. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal.

24. The digital detection method according to claim 23, characterized in that, The process of digitally acquiring the flicker pulse signal and obtaining its amplitude information using a multi-voltage threshold digital readout acquisition card includes the following steps: Multiple thresholds are preset in the multi-voltage threshold digital readout acquisition card, and a threshold interval is formed between two adjacent thresholds. The amplitude information of the flashing pulse signal falls into the threshold interval corresponding to the amplitude information. The amplitude of the flickering pulse signal is compared with a plurality of preset thresholds, and the threshold range corresponding to the amplitude of the flickering pulse signal is determined based on the highest threshold crossed by the flickering pulse signal.

25. The digital detection method according to claim 24, characterized in that, Multiple thresholds are preset in the multi-voltage threshold digital readout acquisition card, and the amplitude of the flashing pulse signal is compared with the preset multiple thresholds using the comparator of the multi-voltage threshold digital readout acquisition card.

26. The digital detection method according to claim 25, characterized in that, The digital detection method also includes: The classification and counting information of the flicker pulse signal is read out by the multi-voltage threshold digital readout circuit configured in the multi-voltage threshold digital readout acquisition card. The multi-voltage threshold digital readout circuit includes multiple digital readout channels, and each readout channel includes multiple comparators.

27. The digital detection method according to claim 25 or 26, characterized in that, The comparator uses multiple low-voltage differential signal input ports of the chip in the multi-voltage threshold digital readout acquisition card.

28. The digital detection method according to claim 24, characterized in that, The energy range is preset in the multi-voltage threshold digital readout acquisition card according to the energy of the photon, and the energy range corresponds to the threshold range.

29. The digital detection method according to claim 28, characterized in that, The step of determining the corresponding energy range based on amplitude information to classify and count the flicker pulse signals includes: The energy range corresponding to the flicker pulse signal is determined based on the threshold range into which the amplitude of the flicker pulse signal falls, and the flicker pulse signal is classified and counted according to the different energy ranges into which it falls.

30. The digital detection method according to claim 29, characterized in that, The blink pulse signals are classified and counted according to the different energy ranges they fall into, using a counting element.

31. The digital detection method according to claim 30, characterized in that, The counting element is realized through multiple digital readout channels of the multi-voltage threshold digital readout circuit configured in the multi-voltage threshold digital readout acquisition card.

32. The digital detection method according to claim 24, characterized in that, The flicker pulse signal is digitally acquired using a multi-voltage threshold digital readout acquisition card, and the amplitude information of the flicker pulse signal is obtained. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal. This is achieved using a multi-voltage threshold digital readout circuit configured inside the multi-voltage threshold digital readout acquisition card.

33. A multi-energy spectral CT imaging method, characterized in that, include: An image reconstruction industrial control computer is used for rapid pre-scanning to adjust the motion control bed to a scanning position that matches the X-ray generator; The image reconstruction industrial control computer starts the X-ray generating device via data transmission. The digital detection device according to any one of claims 10 to 14 is used to count the X-ray sub-energy intervals after attenuation by the object under test, so as to generate projection data; The data transmission industrial control computer receives the projection data and transmits it to the image reconstruction industrial control computer for image reconstruction.

34. The multi-energy spectral CT imaging method according to claim 33, characterized in that, A replaceable power supply is used to power the image reconstruction industrial control computer, the motion control bed, the X-ray generating device, the data transmission industrial control computer, and the digital detection device.

35. The multi-energy spectral CT imaging method according to claim 34, characterized in that, The replaceable power supply uses a modular combination of batteries.

36. The multi-energy spectral CT imaging method according to claim 33, characterized in that, A digital detection device is used to count the X-rays in different energy ranges after they have attenuated through the object under test, in order to generate projection data, including: The digital detection device is used to detect the X-rays to obtain scintillation pulse signals; The flicker pulse signal is digitally acquired using a multi-voltage threshold digital readout acquisition card, and the amplitude information of the flicker pulse signal is obtained. Based on the amplitude information of the flicker pulse signal, the corresponding energy range is determined to classify and count the flicker pulse signal, so as to generate projection data.

37. The multi-energy spectral CT imaging method according to claim 36, characterized in that, The flicker pulse signal is digitally acquired using a multi-voltage threshold digital readout acquisition card to obtain the amplitude information of the flicker pulse signal. The corresponding energy range is determined based on the amplitude information of the flicker pulse signal to classify and count the flicker pulse signal. This is achieved using a multi-voltage threshold digital readout circuit configured within the card.

38. The multi-energy spectral CT imaging method according to claim 37, characterized in that, The energy range is preset according to the energy of the photon in the multi-voltage threshold digital readout circuit, and the energy range corresponds to the threshold range; the multi-voltage threshold digital readout circuit includes multiple digital readout channels, and each readout channel includes multiple comparators and counting elements corresponding to the multiple comparators one by one; The amplitude of the flicker pulse signal is compared with the preset thresholds using the multiple comparators to obtain the highest threshold reached by the flicker pulse signal, thereby determining the threshold range corresponding to the amplitude of the flicker pulse signal. The energy range corresponding to the flicker pulse signal is determined based on the threshold range corresponding to the amplitude of the flicker pulse signal, and multiple counting elements are used to classify and count the flicker pulse signal according to the energy range.

39. The multi-energy spectral CT imaging method according to claim 38, characterized in that, The comparator is a chip with multiple low-voltage differential signal input ports of a multi-voltage threshold digital readout acquisition card.

40. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor is configured to execute the digital detection method of any one of claims 23 to 32 when running the computer program.

41. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor is configured to execute the multi-energy spectral CT imaging method according to any one of claims 33 to 39 when running the computer program.

42. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the digital detection method according to any one of claims 23 to 32.

43. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the multi-energy spectral CT imaging method according to any one of claims 33 to 39.

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