CN115399798A - Photon counting multi-energy spectrum CT imaging device and method - Google Patents
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Abstract
The application provides a photon counting multi-energy spectrum CT imaging device and method, wherein the imaging device comprises: a radiation generating device; an area array probe, the area array probe comprising: a plate-like scintillation crystal configured to convert radiation into visible light; a sheet-shaped microchannel plate, which is coupled with the sheet-shaped scintillation crystal in a one-to-one manner and is configured to select and pass the visible light converted by the sheet-shaped scintillation crystal; a photomultiplier element coupled to the plate-shaped microchannel plate to convert the selectively passed visible light into a scintillation pulse signal; the data transmission industrial personal computer is configured to be in communication connection with the ray generating device and the area array detector so as to control the ray generating device and receive detection data of the area array detector; and the image reconstruction industrial personal computer is configured to be in communication connection with the data transmission industrial personal computer so as to receive the detection data of the surface array detector and perform image reconstruction. The method and the device can reduce optical crosstalk and improve spatial resolution.
Description
Technical Field
The application relates to the technical field of CT imaging, in particular to a photon counting multi-energy spectrum CT imaging device and method.
Background
Existing CT detectors include semiconductor detectors and solid state scintillation detectors (i.e., integral-type detectors). Currently, the international mainstream CT manufacturers have started to lay out in the photon counting field based on semiconductor detectors. The existing photon counting X-ray detector is mainly based on semiconductor silicon, cadmium telluride, cadmium zinc telluride and the like, and although the photon counting detectors have excellent X-ray detection performance, the problems of intolerance to high-flux X-rays, polarization effect, complex reading circuit, high price, environmental protection risk caused by cadmium metal and the like of the cadmium telluride and the cadmium zinc telluride greatly limit the application. The solid-state scintillation detector adopted in the CT system comprises a scintillation crystal and a photoelectric conversion device, high-energy rays can be converted into visible light signals by the scintillation crystal, the visible light signals are further converted into scintillation pulse signals by the photoelectric conversion device, in the process, the imaging spatial resolution has important influence on the final imaging quality, and the current imaging spatial resolution needs to be improved. Taking photon counting multi-energy spectrum CT imaging of small animals as an example, the small animal CT needs the size of a single photoelectric conversion device to be as small as possible so as to improve the imaging spatial resolution, the scintillation crystals of the existing detectors are coupled with the photoelectric conversion device one to one, and the single scintillation crystal needs light shielding, namely, a layer of anti-reflection material for preventing light crosstalk is coated outside the single crystal. The single scintillation crystal cannot be cut to a required small size, and the overall size of a single pixel coated with an anti-reflection material is further increased, so that the size of the single pixel of the detector cannot be small, the imaging spatial resolution is affected, and the single scintillation crystal cannot be used for small animal micro-CT imaging.
Disclosure of Invention
The present application is directed to a photon counting multi-energy spectrum CT imaging apparatus and method to solve at least one of the problems set forth above.
The application provides a photon counting multi-energy spectrum CT imaging device, includes: a radiation generating device; an area array detector, the area array detector comprising: a plate-like scintillation crystal configured to convert radiation into visible light; a plate-shaped microchannel plate, one-to-one coupled with the plate-shaped scintillation crystal, configured to select the visible light converted by the plate-shaped scintillation crystal to pass through; a photomultiplier element coupled to the plate-like microchannel plate to convert the selectively passed visible light into a scintillation pulse signal; the data transmission industrial personal computer is configured to be in communication connection with the ray generating device and the area array detector so as to control the ray generating device and receive detection data of the area array detector; and the image reconstruction industrial personal computer is configured to be in communication connection with the data transmission industrial personal computer so as to receive the detection data of the area array detector and perform image reconstruction.
According to one embodiment of the application, the thickness ratio of the sheet-shaped scintillation crystal to the sheet-shaped microchannel plate collimator is between 1.
According to one embodiment of the application, silicone grease is arranged between the sheet-shaped scintillation crystal and the sheet-shaped micro-channel plate collimator, and silicone grease is arranged between the sheet-shaped micro-channel plate collimator and the photomultiplier element.
According to one embodiment of the application, the ratio of the thickness of the sheet-like microchannel plate collimator to the diameter of the microchannel is between 8.
According to an embodiment of the present application, the photon counting multi-energy spectrum CT imaging apparatus further comprises a multi-voltage threshold digital readout acquisition card configured to digitally acquire the scintillation pulse signal.
According to one embodiment of the application, the multi-voltage threshold digital readout acquisition card is configured to digitally acquire a scintillation pulse signal and acquire amplitude information of the scintillation pulse signal, and the scintillation pulse signal is classified and counted according to an energy interval corresponding to the amplitude information of the scintillation pulse signal.
According to one embodiment of the application, said multi-voltage-threshold digital readout acquisition card is equipped with a multi-voltage-threshold digital readout circuit within which said energy interval is preset according to the energy of said photons, said multi-voltage-threshold digital readout circuit comprising a plurality of digital readout channels, each readout channel comprising: a plurality of comparators, which are configured to preset a plurality of threshold values corresponding to the amplitude of the scintillation pulse signal, wherein a threshold value interval is formed between two adjacent threshold values, and the threshold value intervals correspond to different energy intervals; the amplitude information of the scintillation pulse signal is a threshold interval corresponding to the amplitude of the pulse signal; a plurality of counting elements, which are in one-to-one correspondence with the plurality of comparators and are configured to perform classification counting on the scintillation pulse signals according to the energy interval corresponding to the scintillation pulse signal amplitude information.
According to one embodiment of the present application, the comparator is a plurality of low voltage differential signal input ports LVDS of a multi-voltage threshold digital readout acquisition card.
According to an embodiment of the present application, the photon counting multi-energy spectrum CT imaging apparatus further comprises an image reconstruction module configured to perform image reconstruction on the digital information acquired by the multi-voltage threshold digital readout acquisition card.
According to an embodiment of the application, photon counting multi-energy spectrum CT imaging device still includes removable power, removable power does ray generating device face array detector the data transmission industrial computer and the industrial computer power supply is rebuild to the image.
According to one embodiment of the application, the replaceable power supply is a modular combined battery.
According to an embodiment of the application, photon counting multi-energy spectrum CT imaging device still includes rotating element, ray generating device, face array detector, removable power, data transmission industrial computer, image reconstruction industrial computer are in according to evenly arranging on the rotating element.
According to one embodiment of the application, the rotating element is provided with an opening through which the motion control bed is movable.
According to one embodiment of the application, the photon counting multi-energy spectrum CT imaging device further comprises a grating element which is configured to monitor a rotation angle signal of the rotating element and feed back the rotation angle signal to a data transmission industrial personal computer.
The application provides a photon counting multi-energy spectrum CT imaging method, which comprises the following steps: an image reconstruction industrial personal computer is adopted to carry out rapid pre-scanning so as to adjust the motion control bed to a scanning position matched with the ray generating device; the image reconstruction industrial personal computer controls the ray generation device to start through the data transmission industrial personal computer; counting the ray energy-divided intervals after attenuation of the measured object by using an area array detector to generate projection data; and the data transmission industrial personal computer receives the projection data and transmits the projection data to the image reconstruction industrial personal computer for image reconstruction.
According to an embodiment of the present application, the method for generating projection data by using a surface array detector to count the ray energy-divided intervals after attenuation of a measured object includes: detecting the ray by using the area array detector to obtain a scintillation pulse signal; and digitally collecting the scintillation pulse signals by using a multi-voltage threshold digital reading acquisition card, acquiring amplitude information of the scintillation pulse signals, and determining corresponding energy intervals according to the amplitude information of the scintillation pulse signals so as to classify and count the scintillation pulse signals to generate projection data.
According to an embodiment of the application, a multi-voltage threshold digital reading acquisition card is utilized to digitally acquire the scintillation pulse signals and acquire the amplitude information of the scintillation pulse signals, and the corresponding energy interval is determined according to the amplitude information of the scintillation pulse signals so as to classify and count the scintillation pulse signals, and a multi-voltage threshold digital reading circuit is adopted to realize the classification and counting.
According to one embodiment of the application, the energy interval is preset according to the energy of the photon in a multi-voltage threshold digital readout circuit, and the energy interval corresponds to the threshold interval; the multi-voltage threshold digital readout circuit comprises a plurality of digital readout channels, wherein each readout channel comprises a plurality of comparators and counting elements in one-to-one correspondence with the comparators; presetting a plurality of threshold values by adopting the plurality of comparators, comparing the amplitude of the scintillation pulse signal with the preset plurality of threshold values, and acquiring the highest threshold value reached by the scintillation pulse signal so as to determine a threshold value interval corresponding to the amplitude of the scintillation pulse signal; and determining an energy interval corresponding to the scintillation pulse signal according to a threshold interval corresponding to the amplitude of the scintillation pulse signal, and classifying and counting the scintillation pulse signal according to the energy interval by adopting the plurality of counting elements.
According to one embodiment of the application, a plurality of thresholds are preset in a multi-voltage threshold digital reading acquisition card, and the amplitude of the scintillation pulse signal is compared with the preset thresholds by adopting a comparator of the multi-voltage threshold digital reading acquisition card.
According to one embodiment of the present application, the multiple voltage threshold digital readout circuit includes a plurality of digital readout channels, each readout channel including a plurality of the comparators.
According to one embodiment of the application, a replaceable power supply is adopted to supply power to the image reconstruction industrial personal computer, the motion control bed, the ray generation device, the data transmission industrial personal computer and the photon counting detection device.
The application provides a photon counting multi-energy spectrum CT imaging device and method, adopt the area array detector including slice scintillation crystal, slice microchannel board, photomultiplier array, make the detector pixel by photomultiplier's minimum dimension decision, can make single photomultiplier make the small-size that needs this moment, improved resolution ratio, slice microchannel board carries out the selection to the visible light of scintillation crystal conversion, the visible light of certain angle is incited photomultiplier through its microchannel and is in order to reduce the crosstalk, make scintillation crystal outside need not wrap up anti-reflection material, can effectively utilize scintillation crystal's detection area.
Drawings
Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The accompanying drawings, which are incorporated herein and constitute part of this disclosure, serve to provide a further understanding of the disclosure. The exemplary embodiments of the present disclosure and their description are provided to explain the present disclosure and not to limit the present disclosure. In the drawings:
fig. 1 shows a schematic structural diagram of a detector of a photon counting multi-spectral CT imaging apparatus according to an exemplary embodiment of the present application;
FIG. 2 shows another schematic structural diagram of a photon counting multi-spectral CT imaging apparatus according to an exemplary embodiment of the present application;
FIG. 3 shows a front view of a photon counting multi-spectral CT imaging apparatus according to an exemplary embodiment of the present application;
fig. 4 shows a left side view of a photon counting multi-energy spectral CT imaging apparatus according to an exemplary embodiment of the present application.
Detailed Description
In the following, only certain exemplary embodiments are briefly described. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like are used in the orientations and positional relationships indicated in the drawings, which are merely for convenience of description and simplicity of description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or in communication with each other; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.
The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are merely for purposes of illustrating and explaining the present invention and are not intended to limit the present application.
As shown in fig. 1, according to an exemplary embodiment of the present application, the photon counting multi-energy spectrum CT imaging apparatus disclosed in the present application has an area array detector 100, and the area array detector 100 includes: a sheet-like scintillator crystal 110 configured to convert radiation including high-energy rays such as X-rays, gamma rays, and neutron rays, proton rays, beta rays, and the like into visible light; a sheet microchannel plate 120, one-to-one coupled to the sheet scintillation crystal 110, configured to selectively pass visible light converted by the sheet scintillation crystal 110; an array of photomultiplier elements 130 coupled to the sheet-like microchannel plate 120 to convert the selectively passed visible light into scintillation pulse signals; wherein the sheet-like microchannel plate 120 selects visible light at an angle to be incident on the photomultiplier elements 130 through its microchannels to reduce optical crosstalk.
The detector 100 in the present application adopts an area array detector in which a sheet (or planar) scintillation crystal 110, a sheet microchannel plate 120 and an array of photomultiplier elements 130 are coupled, so that the detector pixels are determined by the minimum size of the photomultiplier elements 130, and at this time, a single photomultiplier element 130 can be processed to a required small size, thereby improving the resolution; and the visible light converted by the X photons is incident to the photomultiplier 130 through the microchannel of the plate 120 by selecting a certain angle of visible light through the microchannel, so as to reduce the optical crosstalk, so that the outside of the scintillation crystal does not need to be coated with an anti-reflection material, and the detection area of the scintillation crystal can be effectively utilized. According to the method, the flaky micro-channel plate 120 is additionally arranged between the flaky (or planar) scintillation crystal 110 and the photomultiplier element 130, so that visible light photons which enter the photomultiplier element at a larger inclination angle are filtered out, namely the visible light photons in a certain angle direction are selected to enter the photomultiplier element through the micro-channel, and optical crosstalk is reduced.
In one embodiment, the photomultiplier elements 130 of the area array detector are silicon photomultiplier tubes (i.e., siPMs). The plate-shaped (planar) scintillation crystal 110 is coupled with the plate-shaped (planar) microchannel plate 120 in a one-to-one manner, and is coupled with the SiPM array to form a scintillation crystal/microchannel plate/SiPM area array detector, and the pixel of the area array detector is determined by the minimum size of the SiPM. The size of a single SiPM can be reduced to 200 mu m or even smaller, and CT imaging with higher resolution of small animal CT can be realized by adopting a detector with smaller pixel size and matching with different adjustable magnification ratios. Meanwhile, the SiPM photonic chip has certain advantages in the aspects of sensitivity, gain and dynamic range, can detect lower light intensity, even can count single photons, and is particularly suitable for low-dose and ultra-low-dose CT imaging.
In a preferred embodiment, the scintillation crystal 110 of the area array detector of the present application employs a low background radiation yttrium lutetium silicate crystal, but is not so limited. The use of the scintillation crystal 110 in place of a semiconductor overcomes the problem of intolerance of high flux X-rays to photon counting detector photosensitive elements based on semiconductor materials.
In one embodiment, the thickness ratio of the sheet-shaped scintillation crystal 110 to the sheet-shaped microchannel plate 120 in the radiation direction is between 1. In a preferred embodiment, the ratio of the thickness of the sheet-like microchannel plate 120 to the diameter of the microchannel is between 8 and 1 to 10, so that the effect of reducing the optical crosstalk can be further improved. Further, the visible light is selected by the sheet-like microchannel plate to be incident on the photomultiplier element through its microchannels at an angle of 0 to 30 degrees to reduce crosstalk of light.
In one embodiment, silicone grease is disposed between the plate-shaped scintillation crystal 110 and the plate-shaped microchannel plate 120, and silicone grease is disposed between the plate-shaped microchannel plate 120 and the photomultiplier 130, so that visible light can be better incident on the silicon photomultiplier.
In an embodiment, the detector 100 may further include a multi-voltage threshold (MVT) digital readout acquisition card configured to digitally acquire the scintillation pulse signal. The multi-voltage threshold digital reading acquisition card is adopted to realize digital reading, so that the position, energy and time information of a single event can be accurately extracted, high-precision signal reduction is completed, and the accurate acquisition of the data of the multi-energy spectrum CT is realized.
In an embodiment, the photon counting multi-energy spectrum CT imaging apparatus of the present application may further include an image reconstruction module configured to perform image reconstruction on the digital information acquired by the multi-voltage threshold digital readout acquisition card. The structural design of the image reconstruction module may adopt the prior art, and is not described herein.
In an embodiment, the photon counting multi-energy spectrum CT imaging apparatus of the present application may further include a radiation generating device configured to emit radiation to the detecting device, wherein the radiation may include X-ray, gamma ray, neutron ray, proton ray, beta ray, and the like.
As shown in fig. 2, a photon counting multi-energy spectrum CT imaging apparatus according to another embodiment of the present application has a detector 200, the detector 200 has at least one energy interval divided according to photon energy, a multi-voltage threshold digital readout acquisition card 210 in the detector 200 is configured to digitally acquire a scintillation pulse signal and obtain amplitude information of the scintillation pulse signal, and the scintillation pulse signal is classified and counted according to the energy interval corresponding to the amplitude information of the scintillation pulse signal.
In one embodiment, the multi-voltage-threshold digital readout acquisition card 210 is equipped with a multi-voltage-threshold (MVT) digital readout circuit in which the energy interval is preset according to the energy of the photons, the multi-voltage-threshold digital readout circuit comprising a plurality of digital readout channels, each readout channel comprising: a plurality of comparators, which are configured to preset a plurality of threshold values corresponding to the amplitude of the scintillation pulse signal, wherein a threshold value interval is formed between two adjacent threshold values, and the threshold value intervals correspond to different energy intervals; the amplitude information of the scintillation pulse signal is a threshold interval corresponding to the amplitude of the pulse signal; a plurality of counting elements, which are in one-to-one correspondence with the plurality of comparators and are configured to perform classification counting on the scintillation pulse signals according to the energy interval corresponding to the scintillation pulse signal amplitude information.
The dedicated digital readout circuit MVT provided with the acquisition card 210 is read out digitally by means of a multi-voltage threshold, so that the radiation photons arriving at the photon counting detection means are recorded in pulses, the amplitude of the recorded pulses being related to the photon energy, and the photon counts of different energies being added to the corresponding energy segments. The amplitude of the pulse corresponds to the energy of the radiation photons and the number of pulses corresponds to the number of photons. Through setting a plurality of threshold values of the electronic system corresponding to the amplitude of the flicker pulse signal, the pulse with lower energy can be filtered, and the influence of low-energy noise on an imaging result is eliminated. Meanwhile, pulse signals with different amplitude heights are screened, energy information of the pulse signals is identified and accumulated corresponding to different energy regions, wider energy spectrum distribution is counted according to set energy intervals, and imaging information of different energy intervals is obtained. Meanwhile, the dedicated multi-voltage threshold digital reading acquisition card 120 is adopted to realize multi-channel measurement, so that the use of a large number of ADCs is avoided, and the cost of the photon counting detection device is greatly reduced.
In one embodiment, 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.
In view of the fact that a solid-state scintillation detector, i.e., an integral detector, which is commonly used in the current CT system is adopted, the total deposition energy of the X-rays is obtained through charge integration for a certain time, the result reflects the average attenuation characteristic of the X-rays, the energy information of the X-rays is lost, and the largest problem of the energy integral detector is that dark current exists, so that the image signal-to-noise ratio is deteriorated under the condition of low dose. Therefore, the photon counting detector is adopted, one or more energy intervals can be divided according to the energy of photons, the photons of the detected energy intervals are counted, multi-energy spectrum CT imaging is realized, electronic noise caused by dark current can be eliminated by setting a proper threshold, the radiation dose is favorably reduced, a higher signal-to-noise ratio is obtained, and low-dose CT imaging is realized; meanwhile, a special multi-voltage threshold digital reading acquisition card is adopted to realize the simultaneous measurement of a plurality of energy channels.
An embodiment of the present application provides a photon counting detection system, including: a photon counting detection device; the data transmission industrial personal computer is configured to be in communication connection with the photon counting detection device so as to receive detection data of the detector; and the image reconstruction industrial personal computer is configured to be in communication connection with the data transmission industrial personal computer so as to receive the detection data and perform image reconstruction. The data transmission industrial personal computer can adopt a computer, a single chip microcomputer, an ARM (advanced RISC machine, processor) or an FPGA (Field-Programmable Gate Array) and the like, and is connected with the photon counting detection device in a Camera Link mode to receive projection data detected by the photon counting detection device; the industrial personal computer for image reconstruction is used as an upper computer, is wirelessly interconnected with the industrial personal computer for data transmission, and can control and store data of the whole system and process images. In one embodiment, the image reconstruction industrial personal computer is a computer, preferably an industrial computer with superior performance.
As shown in fig. 3, an embodiment of the present application provides a small photon counting multi-energy spectrum CT imaging apparatus, including:
a radiation generating device 400; the detector 200 according to the embodiment of the present application; a data transmission industrial personal computer 600 configured to be in communication connection with the ray generation device 400 and the detector 200 to control the ray generation device 400 and receive detection data of the detector 200; and the image reconstruction industrial personal computer 700 is configured to be in communication connection with the data transmission industrial personal computer 600 to receive the detection data of the detector 200 for image reconstruction. The specific design of the data transmission industrial personal computer 600 and the image reconstruction industrial personal computer 700 can refer to a photon counting detection system, and is not described herein in detail.
As shown in fig. 3, the present application provides an animal photon counting multi-energy spectrum CT imaging system 10000, further comprising: a motion control bed 500; a radiation generating device 400; a detector 200; a data transmission industrial personal computer 600 configured to be in communication connection with the ray generation device 400 and the detector 200 to control the ray generation device 400 and receive projection data of the detector 200; and the image reconstruction industrial personal computer 700 is configured to be in communication connection with the data transmission industrial personal computer 600 to receive projection data of the detector 200 and perform image reconstruction. Wherein the radiation generating device 400 generates radiation, such as X-rays or gamma rays; a multi-row area array photon counting detection device formed by a scintillation crystal/microchannel plate/SiPM detector unit of the detector 200 and a multi-voltage threshold digital reading acquisition card detects rays penetrating through a detected object (small animal), counts rays with different energy, and realizes photon counting multi-energy spectrum CT imaging of the small animal.
In the embodiment of the present application, the radiation generating device 400 is used for emitting radiation to the detector 200, and in the preferred embodiment, the X-ray tube is used as the radiation generating device, which has a heavy weight and requires a large power. The radiation is attenuated by the object to be measured (small animal) and reaches the photon counting detection device, and projection data is generated after the radiation is detected by the detector 200.
In an embodiment, the data transmission industrial personal computer 600 and the image reconstruction industrial personal computer 700 are all industrial personal computers with wireless transmission. The data transmission industrial personal computer 600 and the image reconstruction industrial personal computer 700 are lighter than the X-ray bulb tube.
The data transmission industrial personal computer 600 sends a corresponding control signal to the ray generation device 400 to control the ray to be turned on, and projection data generated by the ray attenuated by the object to be detected (small animal) and detected by the detector 200 are transmitted to the data transmission industrial personal computer.
The image reconstruction industrial personal computer 700 is installed on a CT bracket, is provided with a CT imaging system operation interface, and is preset with a scanning protocol. By adjusting software in the CT imaging system operation interface, the rapid pre-scanning of the object to be detected, such as a small animal, can be controlled. The image reconstruction industrial personal computer installed on the CT support is used as an upper computer and is wirelessly interconnected with the data transmission industrial personal computer, and the whole system can be controlled, store data and process images. And the data transmission industrial personal computer transmits data to an image reconstruction industrial personal computer arranged on the CT support, and after scanning is completed, the image reconstruction industrial personal computer reconstructs the received projection data, and the data is post-processed and visualized.
In an embodiment, the animal photon counting multi-energy spectrum CT imaging system 10000 further comprises a replaceable power supply 1200, and the replaceable power supply 1200 is used for supplying power to the system.
In one embodiment of the present application, the replaceable power source 1200 is a modular battery pack. The storage battery is the customization capacity battery, has different voltage and current output, satisfies different power supply demands such as ray generating device, photon count detector, the industrial computer that has wireless transmission, and can adopt the battery of different specifications to make up to the power consumption demand of different equipment, can make the whole reasonable counter weight of equipment, can also make things convenient for in time supply electric quantity, improves scanning efficiency, adopts the CT scanning power supply demand that certain quantity can be guaranteed to modular combination battery. Specifically, the modular combined storage battery comprises a storage battery for supplying power to the ray generating device, a storage battery for supplying power to the photon counting detection device, a storage battery for supplying power to the data transmission industrial personal computer and the image reconstruction industrial personal computer, and the like, and also comprises standby storage batteries with different specifications, wherein the electric quantity of each storage battery is related to components for supplying power to the storage batteries.
In one embodiment, the replaceable power supply 1200 is equipped with a battery level detection system. The battery electric quantity detection system is used for monitoring electric quantity in real time, is in communication connection with the data transmission industrial personal computer and transmits real-time electric quantity information to the data transmission industrial personal computer. The method comprises the steps of presetting electric quantity required by CT scanning in a battery electric quantity detection system, monitoring the electric quantity in real time in the scanning process, automatically calculating the current electric quantity lacking when the current battery electric quantity supplied with power is monitored to be insufficient to support the completion of the scanning work in the scanning process, automatically selecting an auxiliary battery with proper electric quantity matched with the lacking electric quantity from a modularized battery combination, continuously supplying power until the scanning is completed, and supplementing the electric quantity by timely selecting a proper standby storage battery, so that the scanning efficiency is improved. In another embodiment, the battery can be charged when the power is not enough for one CT scan.
In an embodiment, animal photon counting multi-energy spectrum CT imaging system 10000 further comprises a rotating element 300. The data transfer industrial personal computer 600 has a motion controller therein to control the rotary element 300. In the preferred embodiment, the rotating element 300 is a moving dial, but is not limited thereto. In one embodiment, the moving turntable is driven by a direct-drive servo motor to rotate, and the rear end of the moving turntable is connected with the direct-drive servo motor 1000 through a hollow rotary bearing terminal. The motion turntable is used for fixing equipment such as a ray generating device, a photon counting detection device, a modular combined storage battery, a data transmission industrial personal computer 600 and the like. The data transmission industrial personal computer 600 is installed on the motion turntable, a motion controller in the data transmission industrial personal computer is used for controlling the motion turntable, and the control of the components on the motion turntable is realized through the data transmission industrial personal computer 600, and comprises the motion control of the motion control bed 500, the acquisition control of the detector 200, the storage and transmission of projection data, and the real-time monitoring of the battery capacity of the replaceable power supply 1200.
Based on the heaviest ray generating device 400 and 600 times of data transmission industrial personal computers with wireless transmission, the detector 200 is lightest, and the ray generating device 400, the detector 200, the replaceable power supply 1200 and the data transmission industrial personal computers 600 are arranged on the rotating element 300 in a polygonal shape to ensure the stability of the rotating gravity center of the whole moving turntable. The movement turntable controls the ray generating device and the photon counting and detecting device to integrally rotate relative to the measured object so as to acquire projection data of the measured object at different angles.
In an embodiment, the animal photon counting multi-energy spectrum CT imaging system 10000 further comprises a grating element 1100, wherein the grating element 1100 is disposed on the rotating element and configured to monitor a rotation angle signal of the rotating element 300 and feed the rotation angle signal back to the data transmission industrial personal computer 600. In a particular embodiment, the grating element 1100 includes, but is not limited to, a grating scale. The grating ruler is arranged on the motion turntable and used for obtaining the accurate position of the motion turntable in the CT imaging process. The grating ruler, the ray generating device 400, the detector 200, the replaceable power supply 1200, the data transmission industrial personal computer 600 and the like are arranged in a polygon shape. The rotation angle signal of the motion turntable is fed back to the data transmission industrial personal computer through the grating ruler, so that the detector 200 can record the projection of each angle. After the whole 360-degree scanning is completed, the image reconstruction industrial personal computer 700 reconstructs, post-processes and visualizes the projection data of the full angle after receiving the projection data. Replaceable power supply 1200 also includes a battery that supplies power to the grating ruler.
According to the embodiment of the invention, the storage battery supplies power for all the devices such as the ray generating device, the photon counting detection device, the replaceable power supply, the data transmission industrial personal computer, the grating element and the like which are arranged on the motion turntable in a polygonal manner, and can be charged and detachably replaced; the storage battery is a customized capacity storage battery, has different voltage and current outputs, and meets different power supply requirements of the ray generating device, the photon counting detector and the industrial personal computer with wireless transmission. The embodiment of the application uses the storage battery to replace a slip ring for power supply, can guarantee the CT scanning power supply requirements of a certain amount, is provided with a battery power detection system, interacts information with an industrial personal computer with wireless transmission, and can monitor the power in real time. The electric quantity is not enough for one-time CT scanning, and the other group of matched batteries which are charged completely is replaced or the charging is waited.
In one embodiment, the rotating member 300 is provided with an opening 310. Preferably, the opening 310 is provided at the center of the rotating member 300, and when the moving turntable is used as the rotating member, the opening 310 is provided at the center of the moving turntable. The aperture of the opening 310 is larger than the object to be measured (small animal) and the maximum effective detection visual field, and is provided with a position calibration tool for laser calibration. The rear end of the movement turntable is connected with a direct-drive servo motor 1000 through a hollow rotary bearing terminal.
In one embodiment, the motion control bed 500 performs positioning and precession of the object (small animal) to be measured, and the motion control bed 500 is driven by the forward and backward motion servo motor 900 and the up and down motion servo motor 800 to perform forward and backward and up and down movements.
The motion control bed 500 may move through an aperture 310 in the center of the motion carousel. The aperture of the opening 310 of the moving turntable is larger than the diameter of the object to be detected (small animal) and the maximum effective detection visual field, and the moving turntable is provided with a position calibration tool to perform laser calibration on the moving control bed. According to one embodiment of the invention, the motion control bed determines the coordinate origin of the correction coordinate according to laser collimation, one laser beam is arranged in the center of the ray generating device and irradiates the center of the detector, and the other laser beam irradiates the center of the motion turntable in a collimation manner. And adjusting the initial position of the motion control bed according to the pre-scanned image so as to determine the primary irradiation range of the cone beam CT and the initial position of the spiral CT.
According to one embodiment of the present invention, the CT system uses lead plates as the shielding housing, while the door for replacing the object to be tested also has lead plates as the shielding housing. When the object door is not closed, the ray generating device can not be started. In addition, the CT system is designed with two paths of emergency stop and start lights for controlling the ray generating device and a servo motor controller of the direct-drive servo motor, the back-and-forth movement servo motor and the up-and-down movement servo motor to simultaneously and emergently stop working.
The working flow of the small animal photon counting multi-energy spectrum CT imaging system provided by the embodiment of the application is as follows:
the cone beam small animal photon counting multi-energy spectrum CT imaging operation control flow for local high-resolution scanning of the key tissues of the small animal is as follows: after anaesthetizing the small animal to be detected, fixing the small animal to the motion control bed 500, and closing the lead shielding door of the object to be detected; opening a CT imaging system operation interface in an image reconstruction industrial personal computer 700 which is arranged on a CT bracket and has wireless transmission, carrying out rapid pre-scanning, determining whether the position of a detected object (small animal) is proper, and if not, adjusting the position through software in the CT imaging system operation interface until the position reaches the proper position; selecting a scanning protocol, and sending a scanning instruction to a data transmission industrial personal computer 600 installed on the motion turntable through wireless transmission; the motion controller in the data transmission industrial personal computer 600 controls the motion turntable, the data transmission industrial personal computer 600 sends corresponding control signals to the ray generation device 400, after the ray is started, the ray reaches the detector 200 after being attenuated by the measured object, and projection data are generated after being detected by the detector 200; the rotation angle signal of the motion turntable is fed back to the data transmission industrial personal computer 600 through the grating ruler, and the detector 200 records the projection of each angle. And the data transmission industrial personal computer 600 arranged on the moving turntable transmits data to the image reconstruction industrial personal computer 700 arranged on the CT bracket, and after the whole 360-degree scanning is completed, the image reconstruction industrial personal computer arranged on the CT bracket reconstructs, processes and visualizes the image reconstruction industrial personal computer after receiving projection data of a full angle, and finally displays the data in an interface of the image reconstruction industrial personal computer.
In the embodiment of the application, for the whole body scanning of the small animal, the spiral CT is required to be performed, and the spiral CT is realized by switching to a spiral scanning mode. And (3) running a control flow:
fixing the small animal to be detected onto the motion control bed after anesthesia, and closing the lead shielding door of the detected object; opening a CT imaging system operation interface in an image reconstruction industrial personal computer 700 which is arranged on a CT bracket and has wireless transmission, carrying out rapid pre-scanning, determining whether the initial measurement position of a measured object (small animal) is proper, and if not, adjusting through software in the CT imaging system operation interface until the initial measurement position reaches a proper position; selecting a scanning protocol, controlling the motion control bed 500 by a scanning command, and simultaneously sending the scanning command to a data transmission industrial personal computer 600 arranged on the motion turntable through wireless transmission, wherein the motion controller in the data transmission industrial personal computer 600 controls the motion turntable; the data transmission industrial personal computer 600 sends corresponding control signals to the ray generation device 400, after the ray is started, the ray reaches the detector 200 after being attenuated by the detected object, and projection data are generated after being detected by the detector 200; the rotation angle signal of the motion turntable is fed back to the data transmission industrial personal computer 600 through the grating ruler, and the detector 200 records the projection of each angle. The data transmission industrial personal computer 600 installed on the motion turntable transmits data to the image reconstruction industrial personal computer 700 installed on the CT support, and after the whole 360-degree scanning is completed, the image reconstruction industrial personal computer 700 installed on the CT support reconstructs the projection data of the full angle after receiving the projection data, processes the projection data, visualizes the projection data, and finally displays the projection data in an interface of the image reconstruction industrial personal computer 700.
At present, the small animal cone beam CT is widely applied, and a flat panel detector is generally adopted in the cone beam CT. However, the area array of the detector of the detection device for the photon counting multi-energy spectrum CT imaging system for the small animals in the prior art cannot have a large size (only one row or a few rows), and the application of cone beam CT is limited to a certain extent. The multi-row area array detector is adopted, the requirement of cone beam CT imaging can be met, and local high-resolution scanning of some key tissues of small animals is realized. And the whole body scanning of the small animal is completed by switching the spiral scanning mode. Therefore, the multi-array area array detector is adopted, the cone beam and spiral scanning scheme can be switched, and various requirements and use environments of multi-energy spectrum CT imaging can be met.
The application also provides a small photon counting multi-energy spectrum CT imaging method, which comprises the following steps:
an image reconstruction industrial personal computer is adopted to carry out rapid pre-scanning so as to adjust the motion control bed to a scanning position matched with the ray generating device;
the image reconstruction industrial personal computer controls the ray generation device to start through the data transmission industrial personal computer;
the detector according to the embodiment of the application counts the ray energy-divided intervals after attenuation of the measured object to generate projection data;
and the data transmission industrial personal computer receives the projection data and transmits the projection data to the image reconstruction industrial personal computer for image reconstruction.
In one embodiment, a replaceable power supply is adopted to supply power to the image reconstruction industrial personal computer, the motion control bed, the ray generating device, the data transmission industrial personal computer and the photon counting detection device. In a preferred embodiment, the replaceable power supply is a modular combined battery.
In one embodiment, the counting the energy intervals of the attenuated rays of the object to be measured by using a photon counting detector to generate the projection data includes:
the detector of the embodiment of the application is adopted to detect rays so as to obtain a scintillation pulse signal;
and digitally acquiring the scintillation pulse signals by using a multi-voltage threshold digital readout acquisition card, acquiring amplitude information of the scintillation pulse signals, and determining corresponding energy intervals according to the amplitude information of the scintillation pulse signals so as to count the scintillation pulse signals in a classified manner, so as to generate projection data.
In one embodiment, a multi-voltage threshold digital readout acquisition card is used for digitally acquiring the scintillation pulse signals and acquiring amplitude information of the scintillation pulse signals, corresponding energy intervals are determined according to the amplitude information of the scintillation pulse signals so as to classify and count the scintillation pulse signals, and a multi-voltage threshold digital readout circuit configured in the energy intervals is used for realizing the classification and counting.
In the embodiment of the application, the step of digitally acquiring the scintillation pulse signal and acquiring the amplitude information of the scintillation pulse signal by using the multi-voltage threshold digital readout acquisition card comprises the following steps: presetting a plurality of threshold values in a multi-voltage threshold digital reading acquisition card; and comparing the amplitude of the scintillation pulse signal with a plurality of preset threshold values, and acquiring the highest threshold value reached by the scintillation pulse signal to determine a threshold value interval corresponding to the amplitude of the scintillation pulse signal.
In one embodiment, the presetting of the multiple thresholds in the multi-voltage-threshold digital reading acquisition card is realized by adopting a comparator of the multi-voltage-threshold digital reading acquisition card. Specifically, a multi-voltage threshold digital reading circuit is configured in the multi-voltage threshold digital reading acquisition card, and comprises a plurality of digital reading channels, and each reading channel comprises a plurality of comparators. In a preferred embodiment, the comparator is a plurality of low-voltage differential signal input ports LVDS of a chip of the multi-voltage threshold digital readout acquisition card.
In an embodiment, a threshold interval is formed between two adjacent thresholds, and the amplitude information of the blinking pulse signal is the threshold interval corresponding to the amplitude of the pulse signal.
In one embodiment, the comparison between the amplitude of the scintillation pulse signal and a plurality of preset thresholds is realized by adopting a comparator of a multi-voltage threshold digital readout acquisition card. The comparator is a plurality of low-voltage differential signal input ports LVDS of a chip of the multi-voltage threshold digital readout acquisition card.
In one embodiment, an energy interval is preset in the multi-voltage threshold digital readout acquisition card according to the energy of photons, and the energy interval corresponds to the threshold interval.
In one embodiment, the step of determining the corresponding energy interval according to the amplitude information to classify and count the scintillation pulse signal comprises: and determining an energy interval corresponding to the scintillation pulse signal according to a threshold interval corresponding to the amplitude of the scintillation pulse signal, and classifying and counting the scintillation pulse signal according to the energy interval.
In a preferred embodiment, the counting of the scintillation pulse signals classified by the energy interval is realized by using a counting element.
In one embodiment, each read channel of the multiple voltage threshold digital sensing circuit includes a plurality of counting elements.
In another embodiment of the present application, the step "digitally acquiring the scintillation pulse signal and acquiring the amplitude information of the scintillation pulse signal by using a multi-voltage threshold digital readout acquisition card, and determining the corresponding energy interval according to the amplitude information of the scintillation pulse signal so as to perform classification counting on the scintillation pulse signal" is implemented by using a multi-voltage threshold digital readout circuit configured therein.
In a preferred embodiment, an energy interval is preset in a multi-voltage threshold digital reading acquisition card according to the energy of photons, and the energy interval corresponds to a threshold interval; the multi-voltage threshold digital reading acquisition card comprises a plurality of digital reading channels, wherein each reading channel comprises a plurality of comparators and counting elements in one-to-one correspondence with the comparators; presetting a plurality of threshold values by adopting a plurality of comparators, comparing the amplitude of the scintillation pulse signal with the preset threshold values, and acquiring the highest threshold value reached by the scintillation pulse signal to determine a threshold value interval corresponding to the amplitude of the scintillation pulse signal; and determining an energy interval corresponding to the scintillation pulse signal according to a threshold interval corresponding to the amplitude of the scintillation pulse signal, and classifying and counting the scintillation pulse signal according to the energy interval by adopting a plurality of counting elements.
The apparatus described in the embodiments of the present application may incorporate the method features described in the embodiments of the present application and vice versa.
Various embodiments are described herein, but for the sake of brevity, the description of various embodiments is not intended to be exhaustive, and features or components that are the same or similar between various embodiments may be omitted. As used herein, "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" is intended to apply to at least one embodiment or example, but not to all embodiments, in accordance with the present application. The above terms are not necessarily meant to refer to the same embodiment or example. Those skilled in the art will be able to combine and combine features of different embodiments or examples and features of different embodiments or examples described in this specification without contradiction.
Finally, it should be noted that: although the present disclosure has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described above, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.
Claims (21)
1. A photon counting multi-energy spectrum CT imaging apparatus, comprising:
a radiation generating device;
an area array probe, the area array probe comprising: a plate-like scintillation crystal configured to convert radiation into visible light; a plate-shaped microchannel plate, one-to-one coupled with the plate-shaped scintillation crystal, configured to selectively pass the visible light converted by the plate-shaped scintillation crystal; a photomultiplier element coupled to the plate-like microchannel plate to convert the selectively passed visible light into a scintillation pulse signal;
the data transmission industrial personal computer is configured to be in communication connection with the ray generating device and the area array detector so as to control the ray generating device and receive detection data of the area array detector;
and the image reconstruction industrial personal computer is configured to be in communication connection with the data transmission industrial personal computer so as to receive the detection data of the area array detector and carry out image reconstruction.
2. The photon counting multi-energy spectrum CT imaging device according to claim 1, wherein the thickness ratio of the sheet-like scintillation crystal to the sheet-like microchannel plate collimator is between 1.
3. The photon counting multi-energy spectrum CT imaging device according to claim 1, wherein the ratio of the thickness of the sheet-like microchannel plate collimator to the diameter of the microchannel is between 8 and 10.
4. The photon counting multi-energy spectrum CT imaging device according to claim 1, wherein silicone grease is arranged between the sheet-shaped scintillation crystal and the sheet-shaped microchannel plate collimator, and silicone grease is arranged between the sheet-shaped microchannel plate collimator and the photomultiplier element.
5. The photon counting multi-energy spectrum CT imaging device according to claim 1, further comprising a multi-voltage threshold digital readout acquisition card configured to digitally acquire the scintillation pulse signals.
6. The photon counting multi-energy spectrum CT imaging device according to claim 5, wherein the multi-voltage threshold digital readout acquisition card is configured to digitally acquire the scintillation pulse signals and acquire the amplitude information of the scintillation pulse signals, and the scintillation pulse signals are classified and counted according to the energy interval corresponding to the amplitude information of the scintillation pulse signals.
7. The photon counting multi-energy spectrum CT imaging device according to claim 6, wherein said multi-voltage threshold digital readout acquisition card is equipped with a multi-voltage threshold digital readout circuit within which said energy interval is preset according to the energy of said photons, said multi-voltage threshold digital readout circuit comprising a plurality of digital readout channels, each readout channel comprising:
a plurality of comparators configured to preset a plurality of threshold values corresponding to the amplitude of the scintillation pulse signal, wherein two adjacent threshold values form a threshold value interval therebetween, and the threshold value intervals correspond to different energy intervals; the amplitude information of the scintillation pulse signal is a threshold interval corresponding to the amplitude of the pulse signal;
a plurality of counting elements, which are in one-to-one correspondence with the plurality of comparators and are configured to perform classification counting on the scintillation pulse signals according to the energy interval corresponding to the scintillation pulse signal amplitude information.
8. The photon counting multi-energy spectrum CT imaging apparatus according to claim 7, wherein the comparator is a plurality of low voltage differential signal input ports LVDS of a multi-voltage threshold digital readout acquisition card.
9. The photon counting multi-energy spectrum CT imaging device of claim 5, further comprising an image reconstruction module configured to image reconstruct the digitized information collected by the multi-voltage threshold digital readout acquisition card.
10. The photon counting multi-energy spectrum CT imaging device according to claim 1, further comprising a replaceable power supply, wherein the replaceable power supply supplies power to the ray generating device, the area array detector, the data transmission industrial personal computer and the image reconstruction industrial personal computer.
11. The photon counting multi-energy spectrum CT imaging apparatus according to claim 10, wherein said replaceable power supply is a modular combined battery.
12. The photon counting multi-energy spectrum CT imaging device according to claim 10, further comprising a rotating element, wherein the ray generating device, the area array detector, the replaceable power supply, the data transmission industrial personal computer and the image reconstruction industrial personal computer are uniformly arranged on the rotating element.
13. The photon counting multi-energy spectrum CT imaging apparatus according to claim 12, wherein the rotating element is provided with an aperture through which a motion control bed is movable.
14. The photon counting multi-energy spectrum CT imaging apparatus of claim 12, further comprising a grating element configured to monitor a rotation angle signal of the rotating element and feed back to a data transmission industrial computer.
15. A photon counting multi-energy spectrum CT imaging method is characterized by comprising the following steps:
an image reconstruction industrial personal computer is adopted to carry out rapid pre-scanning so as to adjust the motion control bed to a scanning position matched with the ray generating device;
the image reconstruction industrial personal computer controls the ray generating device to start through the data transmission industrial personal computer;
counting the ray energy-divided intervals after attenuation of the measured object by using an area array detector to generate projection data;
and the data transmission industrial personal computer receives the projection data and transmits the projection data to the image reconstruction industrial personal computer for image reconstruction.
16. The photon counting multi-energy spectrum CT imaging method according to claim 15, wherein the step of counting the energy-divided intervals of the rays attenuated by the object to be measured by the planar array detector to generate the projection data comprises:
detecting the ray by using the area array detector to obtain a scintillation pulse signal;
and digitally collecting the scintillation pulse signals by using a multi-voltage threshold digital reading acquisition card, acquiring amplitude information of the scintillation pulse signals, and determining corresponding energy intervals according to the amplitude information of the scintillation pulse signals so as to classify and count the scintillation pulse signals to generate projection data.
17. The photon counting multi-energy spectrum CT imaging method of claim 15,
the method comprises the steps of digitally collecting the scintillation pulse signals by using a multi-voltage threshold digital reading acquisition card, acquiring amplitude information of the scintillation pulse signals, determining corresponding energy intervals according to the amplitude information of the scintillation pulse signals so as to classify and count the scintillation pulse signals, and achieving the purpose by using a multi-voltage threshold digital reading circuit.
18. The photon counting multi-energy spectrum CT imaging method according to claim 17, wherein the energy interval is preset according to the energy of the photons in a multi-voltage threshold digital readout circuit, the energy interval corresponding to the threshold interval; the multi-voltage threshold digital readout circuit comprises a plurality of digital readout channels, wherein each readout channel comprises a plurality of comparators and counting elements in one-to-one correspondence with the comparators;
presetting a plurality of threshold values by adopting the plurality of comparators, comparing the amplitude of the scintillation pulse signal with the preset plurality of threshold values, and acquiring the highest threshold value reached by the scintillation pulse signal so as to determine a threshold value interval corresponding to the amplitude of the scintillation pulse signal;
and determining an energy interval corresponding to the scintillation pulse signal according to a threshold interval corresponding to the amplitude of the scintillation pulse signal, and classifying and counting the scintillation pulse signal according to the energy interval by adopting the plurality of counting elements.
19. The photon counting multi-energy spectrum CT imaging method according to claim 17, wherein a plurality of thresholds are preset in a multi-voltage threshold digital readout acquisition card, and the comparison between the amplitude of the scintillation pulse signal and the preset thresholds is implemented by using a comparator of the multi-voltage threshold digital readout acquisition card.
20. The photon counting multi-energy spectrum CT imaging method according to claim 17, wherein said multi-voltage threshold digitizing readout circuit comprises a plurality of digitizing readout channels, each readout channel comprising a plurality of said comparators.
21. The photon counting multi-energy spectrum CT imaging method according to claim 15, characterized in that a replaceable power supply is used to supply power to the image reconstruction industrial personal computer, the motion control bed, the ray generating device, the data transmission industrial personal computer and the photon counting detection device.
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| CN116594051B (en) * | 2023-05-31 | 2024-01-26 | 中山大学 | Large-area high-space and time resolution superhard x-ray imaging system |
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