Multi-mode imaging system

Abstract

The present invention is applicable to the field of medical imaging technology, and discloses a multi-mode imaging system, which includes a display, a multi-mode imaging device, and a host electrically connected between the display and the multi-mode imaging device, wherein an image reconstruction and processing subsystem is provided in the host, and an animal scanning control subsystem, a static computed tomography imaging subsystem, and a photoacoustic imaging subsystem are provided in the multi-mode imaging device, wherein the static computed tomography imaging subsystem includes an electronic control circuit, a multi-beam carbon nanometer X-ray source array for generating X-rays required for static computed tomography scanning, a photon counting detector for computed tomography projection data acquisition and high-speed processing, and a power supply for supplying power to the multi-beam carbon nanometer X-ray source array, wherein the multi-beam carbon nanometer X-ray source array, the photon counting detector, and the power supply are all electrically connected to the electronic control circuit. The multi-mode imaging system of the present invention has high image resolution, large imaging depth, and low radiation dose.

Description

Technical Field

[0001] The present invention relates to the field of medical imaging technology, and in particular to a multi-mode imaging system. Background Art

[0002] Cancer is the most common type of malignant tumor and the number one killer threatening human health. Currently, the number of cancer cases worldwide is growing rapidly, with new cases mainly coming from developing countries. Due to its high mortality rate, high disability rate and heavy medical burden, malignant tumors have become a public health and even social issue that must be taken seriously worldwide. Among the factors that cause death in patients caused by cancer, tumor metastasis is the most important factor.

[0003] At present, the study of tumor metastasis is mainly conducted on small animals represented by mice and rats. In specific research, a tumor disease model is first established in small animals, and then the physiological-pathological characteristics of tumor metastasis are studied, new cancer diagnostic technologies, anti-tumor drugs are developed, and the efficacy of drugs is evaluated. Among various methods for studying small animals, the whole-body in vivo imaging technology of small animals can conduct whole-body and long-term observations of the same batch of small animals at different time points, greatly reducing experimental costs and obtaining repeated and reliable experimental data. At the same time, with the help of highly sensitive molecular probes, effective observations can be made in the early stages of tumor metastasis, thereby achieving full monitoring of the entire metastasis process of tumor cells. The main imaging technologies involved include structural imaging such as computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound imaging (Ultrasound), as well as functional imaging such as photoacoustic imaging (Photoacoustic Imaging), positron emission tomography (PET) and single photon emission computed tomography (SPECT). However, the information obtained by these single-modality imaging technologies has certain limitations and cannot fully reflect the complex specificity of organisms, resulting in the inability to provide comprehensive and accurate information for tumor metastasis research.

[0004] In view of the above-mentioned shortcomings of single-modality imaging technology, the existing technology has proposed multimodality imaging technology that combines structural and functional information, and multimodality imaging technology is increasingly being used in whole-body in vivo imaging of small animals. For example, multimodality imaging technology that combines PET and CT has become the clinical reference standard for multimodality molecular imaging. It has demonstrated its value in predicting the efficacy of neoadjuvant therapy and new targeted therapy, and has recently been used to detect early tumor metastasis. For example, multimodality imaging technology that combines optical imaging and PET has been used to detect lymphangiogenesis induced during tumor metastasis.

[0005] However, in the prior art, there are still certain deficiencies in the whole-body in vivo multimodal imaging technology of small animals. For example, in PET-CT imaging, the accuracy and resolution of PET can be improved by relying on the attenuation coefficient map of high-energy photons obtained from CT images; however, compared with PET or SPECT, near-infrared photons are more easily affected by the tissue light absorption coefficient than high-energy photons. Therefore, the use of the attenuation correction concept in optical imaging can obtain better imaging effects. In addition, in cancer treatment, due to the low spatial resolution of PET / SPECT, it is difficult to accurately describe the targeting and aggregation of drugs. In order to simultaneously obtain the overall and local drug metabolism, dual-mode probes that can respond to optical modalities are often used for drug evaluation and analysis. However, due to the strong scattering effect of the organism, the imaging depth of optical imaging technology is often only about 1 mm, which limits its application. In addition, among the modalities that can provide high-resolution structural imaging, CT imaging has advantages in displaying anatomical structure, morphology, and density, and has a fast imaging speed. It can also enhance soft tissue contrast by injecting contrast agents, using energy spectrum imaging, or phase contrast imaging. However, excessive X-ray radiation will change the physiological structure of small animals and affect the correct judgment of the cancer development and metastasis process and drug effects. When using in vivo imaging technology to conduct long-term longitudinal studies on small animals, it is also necessary to ensure that the radiation dose received by the small animals is as low as possible to reduce its physiological effects on the small animals. It can be seen that the existing in vivo whole-body multi-modality imaging technology for small animals still generally has problems such as low image resolution, small imaging depth, and high radiation dose in specific applications. Summary of the invention

[0006] The purpose of the present invention is to provide a multi-mode imaging system, which aims to solve the technical problems of low image resolution, small imaging depth and high radiation dose in specific applications of existing small animal living whole-body multi-mode imaging technology.

[0007] To achieve the above-mentioned purpose, the solution provided by the present invention is: a multi-mode imaging system, including a display, a multi-mode imaging device and a host electrically connected between the display and the multi-mode imaging device, the host is provided with an image reconstruction and processing subsystem, the multi-mode imaging device is provided with an animal scanning control subsystem, a static computed tomography subsystem and a photoacoustic imaging subsystem, the static computed tomography subsystem includes an electronic control circuit, a multi-beam carbon nanometer X-ray source array for generating X-rays required for static computed tomography scanning, a photon counting detector for computed tomography projection data acquisition and high-speed processing and a power supply for powering the multi-beam carbon nanometer X-ray source array, the multi-beam carbon nanometer X-ray source array, the photon counting detector and the power supply are all electrically connected to the electronic control circuit.

[0008] Optionally, the multi-beam carbon nanometer X-ray source array includes a plurality of carbon nanometer X-ray sources distributed in an array, the carbon nanometer X-ray source including a vacuum chamber, a carbon nanometer field emission cathode, a gate, a focusing electrode and an anode, the carbon nanometer field emission cathode, the gate, the focusing electrode and the anode are all arranged in the vacuum chamber, the anode is arranged obliquely above the carbon nanometer field emission cathode, the gate and the focusing electrode are both arranged between the carbon nanometer field emission cathode and the anode, and the gate is located between the focusing electrode and the carbon nanometer field emission cathode, and the vacuum chamber is provided with an X-ray exit window located next to the anode.

[0009] Optionally, the carbon nano field emission cathode includes a substrate and a cold cathode material layer disposed on a surface of the substrate.

[0010] Optionally, the substrate is a metal substrate or a silicon wafer coated with a metal coating; and / or,

[0011] The material of the cold cathode material layer is carbon nanotubes or graphene or a mixture of carbon nanotubes and graphene.

[0012] Optionally, the number of the carbon nano-X-ray sources is 90-180; and / or,

[0013] Each of the carbon nano-X-ray sources is distributed in a circular array or a polygonal array; and / or,

[0014] The X-ray exit window is an aluminum window or a beryllium window; and / or,

[0015] The vacuum degree of the vacuum chamber is 10 -6 mmHg~10 -11 mmHg; and / or,

[0016] The grid comprises a support and a grid disposed on the support, wherein the grid has an opening for electrons to pass through; and / or,

[0017] The anode is inclined at an angle of 5° to 15° relative to the horizontal plane; and / or,

[0018] The relative distances among the carbon nanometer field emission cathode, the grid electrode, the focusing electrode and the anode are adjusted by insulating spacers.

[0019] Optionally, the photoacoustic imaging subsystem includes an optical subsystem for providing excitation light required for photoacoustic imaging, an acoustic subsystem for collecting multi-channel photoacoustic signals, and a photoacoustic coplanarity adjustment subsystem for adjusting the incident angle of the excitation light to ensure that the optical signal and the acoustic signal remain coplanar.

[0020] Optionally, the optical subsystem includes an excitation light source, a lens group, a fiber optic bundle and an annular light bowl, the lens group is arranged between the excitation light source and the fiber optic bundle, and the fiber optic bundle is fixed on the annular light bowl and located between the lens group and the annular light bowl.

[0021] Optionally, the acoustic subsystem includes a high-frequency ultrasonic transducer array for detecting acoustic signals and a multi-channel data acquisition platform for processing the detection signals of the high-frequency ultrasonic transducer array.

[0022] Optionally, the high-frequency ultrasonic transducer array includes a plurality of high-frequency ultrasonic transducers distributed in an array, and the high-frequency ultrasonic transducer is a multi-layer stacked structure, which includes an acoustic lens, a matching layer, a piezoelectric composite material layer, and an insulating backing layer stacked in sequence from front to back.

[0023] Optionally, the animal scanning control subsystem includes a positioning structure for positioning the animal and an electromechanical control platform for driving the positioning structure and the animal on the positioning structure to move in a vertical direction; and / or,

[0024] The image reconstruction and processing subsystem includes an image reconstruction model group carrying an image reconstruction algorithm, an image calibration module carrying image correction and registration software, an image fusion module carrying multimodal image fusion software, and an information output module carrying information extraction and display software.

[0025] The multi-mode imaging system provided by the present invention adopts a multi-mode imaging technology formed by combining a static CT imaging subsystem with a photoacoustic imaging subsystem, which realizes the synchronous acquisition of small animal structure and function information, and has the advantages of high image resolution, fast imaging speed, large imaging depth, low radiation dose, and long-term monitoring compared with the existing multi-mode imaging system. Specifically, compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The static CT imaging subsystem using a multi-beam carbon nano-X-ray source array does not require mechanical rotation, and only requires rapid switching between the various carbon nano-X-ray sources to achieve high-speed CT scanning; and the static CT imaging subsystem overcomes the limitation of mechanical rotation speed, has a higher imaging speed, and eliminates artifacts caused by movement, thereby achieving higher spatial resolution. In addition, since the multi-beam carbon nano-X-ray source array can perform high-speed pulse emission, it greatly reduces the ineffective radiation dose during the CT scanning process, thereby achieving an ultra-low radiation effect.

[0027] (2) Unlike optical imaging technology, the spatial resolution of photoacoustic imaging technology comes from ultrasound signals, and the ultrasound scattering of biological tissue is two orders of magnitude weaker than the light scattering. Therefore, the photoacoustic imaging technology used in the present invention has both high optical contrast and the ability of ultrasound to perform high-resolution imaging of deep tissues. At the same time, with the addition of molecular probes, it can also have the advantages of high sensitivity, non-radioactivity, and high specificity.

[0028] (3) The integration of static CT imaging technology and photoacoustic imaging technology has the characteristics of complementary advantages, mutual coordination, and mutual comparison. On the one hand, with the advantages of high resolution and ultra-low radiation of static CT imaging, it is easy to perform three-dimensional visualization to locate tumor tissue. On the other hand, by utilizing the advantages of excellent soft tissue contrast and high sensitivity of photoacoustic imaging, it can achieve early and accurate diagnosis of tumor metastasis and precise description of drug metabolism. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 is a schematic structural diagram of a multi-mode imaging system provided by an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of a carbon nanometer X-ray source provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0035] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] like Figure 1 and Figure 2As shown, the multi-mode imaging system provided by the embodiment of the present invention includes a display 100, a multi-mode imaging device 200 and a host 300 electrically connected between the display 100 and the multi-mode imaging device 200, the host 300 is provided with an image reconstruction and processing subsystem (not shown), the multi-mode imaging device 200 is provided with an animal scanning control subsystem 210, a static computed tomography imaging subsystem 220 (i.e., a static CT imaging subsystem) and a photoacoustic imaging subsystem 230, the static computed tomography imaging subsystem 220 includes an electronic control circuit 221, a multi-beam carbon nanometer X-ray source array 222 for generating X-rays 500 required for static computed tomography scanning, a photon counting detector 223 for computed tomography projection data acquisition and high-speed processing, and a power supply 224 for supplying power to the multi-beam carbon nanometer X-ray source array 222, the multi-beam carbon nanometer X-ray source array 222, the photon counting detector 223 and the power supply 224 are all electrically connected to the electronic control circuit 221. The multi-mode imaging device 200 is mainly used to scan and image the animal 400, the host 300 is mainly used to process the information of the multi-mode imaging device 200, and the display 100 is mainly used to intuitively output the information processed by the host 300. Among them, in the multi-mode imaging device 200, the animal scanning control subsystem 210 is mainly used to carry the animal 400 and carry the animal 400 to move, the static computer tomography imaging subsystem 220 is mainly used to perform structural imaging on the animal 400, and the photoacoustic imaging subsystem 230 is mainly used to perform functional imaging on the animal 400.

[0037] Specifically, in the embodiment of the present invention, the static CT imaging subsystem using the multi-beam carbon nanometer X-ray source array 222 can achieve high-speed CT scanning by quickly switching between the various carbon nanometer X-ray sources 2220 without mechanical rotation; and the static CT system overcomes the limitation of mechanical rotation speed, has a higher imaging speed, and eliminates artifacts caused by movement, thereby obtaining a higher spatial resolution. In addition, since the multi-beam carbon nanometer X-ray source array 222 can perform high-speed pulse emission, the ineffective radiation dose during the CT scanning process is greatly reduced, thereby achieving the effect of ultra-low radiation.

[0038] In addition, since the spatial resolution of the photoacoustic imaging sub-technology comes from the ultrasonic signal, and the ultrasonic scattering of biological tissue is two orders of magnitude weaker than the light scattering, the photoacoustic imaging technology used in the embodiment of the present invention has both high optical contrast and the ability of ultrasound to perform high-resolution imaging of deep tissues. At the same time, with the addition of molecular probes, it can also have the advantages of high sensitivity, non-radioactivity, and high specificity.

[0039] Since the imaging times of the photoacoustic and static CT imaging subsystems are different, when the system is working, the trigger signal of the photoacoustic subsystem can be accurately controlled by the clock of the static CT imaging subsystem 220, so that it can be acquired synchronously according to the acquisition timing of the static CT imaging subsystem 220, thereby realizing synchronous imaging of the two.

[0040] The multi-mode imaging system provided by the embodiment of the present invention adopts a scheme that integrates static CT imaging technology and photoacoustic imaging technology, and has the characteristics of complementary advantages, mutual cooperation, and mutual comparison. On the one hand, with the advantages of high resolution and ultra-low radiation of static CT imaging, it is easy to perform three-dimensional visualization to locate tumor tissue. On the other hand, by utilizing the advantages of excellent soft tissue contrast and high sensitivity of photoacoustic imaging, it can achieve early and accurate diagnosis of tumor metastasis and accurate description of drug metabolism. Therefore, the multi-mode imaging system provided by the embodiment of the present invention adopts a multi-mode imaging technology formed by combining a static computer tomography imaging subsystem 220 with a photoacoustic imaging subsystem 230, which not only realizes the synchronous acquisition of the structure and function information of the animal 400, but also has the advantages of high image resolution, fast imaging speed, large imaging depth, low radiation dose, and long-term monitoring.

[0041] Preferably, the multi-beam carbon nanometer X-ray source array 222 includes a plurality of carbon nanometer X-ray sources 2220 distributed in an array, the carbon nanometer X-ray source 2220 includes a vacuum chamber 2221, a carbon nanometer field emission cathode 2222, a gate 2223, a focusing electrode 2224 and an anode 2225, the carbon nanometer field emission cathode 2222, the gate 2223, the focusing electrode 2224 and the anode 2225 are all arranged in the vacuum chamber 2221, the anode 2225 is arranged at intervals and tilted above the carbon nanometer field emission cathode 2222, the gate 2223 and the focusing electrode 2224 are both arranged between the carbon nanometer field emission cathode 2222 and the anode 2225, and the gate 2223 is located between the focusing electrode 2224 and the carbon nanometer field emission cathode 2222, and the vacuum chamber 2221 is provided with an X-ray exit window 2226 located next to the anode 2225. The multi-beam carbon nanometer X-ray source array 222 is used to generate X-rays 500 of different projection angles required for static CT scanning, the photon counting detector 223 is used for the collection and high-speed processing of CT projection data, and the power supply 224 is used to supply power to the multi-beam carbon nanometer X-ray source array 222. The carbon nanometer X-ray source 2220 has the characteristics of stable current, good high-voltage resistance, and small focal spot. Specifically, the tube current of the carbon nanometer X-ray source 2220 is greater than 0.1 mA, the tube voltage is greater than 50 kV, and the focal spot is less than 0.1 mm.

[0042] Preferably, the carbon nanometer X-ray sources 2220 are distributed in a circular array or a polygonal array, and the number of the carbon nanometer X-ray sources 2220 is 90-180, which is conducive to achieving 360° full coverage of the scanning angle.

[0043] Preferably, the X-ray exit window 2226 is an aluminum window or a beryllium window.

[0044] Preferably, the vacuum degree of the vacuum chamber 2221 is 10 -6 mmHg~10 -11 mmHg.

[0045] Preferably, the carbon nano field emission cathode 2222 includes a substrate and a cold cathode material layer disposed on the surface of the substrate. The cold cathode material layer can be prepared by electrophoretic deposition or chemical vapor deposition, and its shape and size can be precisely controlled by photolithography; in addition, the shape of the cold cathode material layer is preferably elliptical or rectangular to obtain a focus with consistent size in all directions.

[0046] Preferably, the substrate is a metal substrate or a silicon wafer coated with a metal coating; the metal substrate can specifically be a stainless steel sheet, a copper sheet, a titanium sheet, a molybdenum sheet, etc., and the metal coating can specifically be a copper coating, a titanium coating, a molybdenum coating, or iron, etc.

[0047] Preferably, the material of the cold cathode material layer is carbon nanotubes or graphene or a mixture of carbon nanotubes and graphene.

[0048] Preferably, the carbon nano field emission cathode 2222 is placed on the base of the vacuum chamber 2221 .

[0049] Preferably, the grid 2223 includes a support and a grid disposed on the support, and the grid has an opening for electrons to pass through. The grid 2223 is mainly used to provide an electric field required for the cold cathode material layer to emit electrons. The opening on the grid is mainly used to ensure that the electrons can pass through the grid 2223 to reach the anode 2225. The grid includes but is not limited to a tungsten mesh or a molybdenum mesh.

[0050] Preferably, the inclination angle A formed by the anode 2225 relative to the horizontal plane is 5° to 15°. The anode 2225 is mainly used for accelerating the electron beam to obtain high-energy electrons. The anode 2225 has a reflection target, which is mainly used to reflect the X-rays 500 generated by the electron bombardment. The reflection target can be a tungsten target or a molybdenum target.

[0051] Specifically, the focusing electrode 2224 is mainly used to focus the electron beam to obtain a focus of a desired size. The focusing electrode 2224 is provided with a focusing hole, which can be a rotationally symmetrical circular hole, or a rotationally non-symmetrical elliptical hole or a rectangular hole.

[0052] Preferably, the relative distances between the carbon nano field emission cathode 2222, the gate 2223, the focusing electrode 2224 and the anode 2225 are adjusted by an insulating spacer (not shown), so as to achieve the best focusing effect.

[0053] Preferably, the power supply 224 includes two medium and low voltage power supplies and one high voltage power supply. The medium and low voltage power supplies are respectively connected to the grid 2223 and the focusing electrode 2224, with a voltage range of 2kV-5kV; the high voltage power supply is connected to the anode 2225, with a power supply range of 50kV-140kV.

[0054] Specifically, the photon counting detector 223 has the characteristics of high-speed data acquisition, high spatial resolution and high power resolution, and can give full play to the advantages of high-speed pulse exposure of the carbon nano X-ray source array 222. The photon counting detector 223 is in the shape of a ring or a polygon, and its X-ray photon conversion material can be cadmium telluride or cadmium zinc telluride. The vertical dimension of the photon counting detector 223 is preferably greater than 0.5 cm, and the pixel is preferably less than 100 microns.

[0055] Preferably, the electronic control circuit 221 includes a pulse drive and timing control circuit, a current consistency control circuit, and a parallel exposure and data acquisition control circuit. Among them, the pulse drive and timing control circuit is used to realize the switch of the carbon nanometer X-ray source 2220 and the adjustment of the exposure time, and to realize the rapid switching between different carbon nanometer X-ray sources 2220. Due to the limitation of the preparation process, the field emission performance of the cathode is inevitably different, and the current consistency control system can modulate the emission current of the cathode by accurately adjusting the gate 2223 voltage of each carbon nanometer X-ray source 2220, so that different carbon nanometer X-ray sources 2220 can maintain the consistency of current during operation, thereby ensuring that the exposure dose at different angles is the same. The parallel exposure and data acquisition circuit mainly triggers the opening of the carbon nanometer X-ray source 2220 through the trigger signal when the detector is turned on, thereby realizing the synchronous exposure of the carbon nanometer X-ray source 2220 and the data acquisition of the detector.

[0056] Preferably, the pulse drive and timing control circuit includes a drive circuit, a control circuit and an isolation protection circuit. Among them, the drive circuit is preferably a drive circuit based on IGBT (Insulated Gate Bipolar Transistor), which is mainly used to realize the control of weak current signals over strong current signals (kilovolt high voltage); the control circuit is preferably a control circuit based on FPGA (Field-Programmable Gate Array), which is mainly used to realize the output of programmable signals with high time accuracy; the isolation circuit is mainly used to ensure effective protection of the control system.

[0057] Preferably, the current consistency control circuit comprises a gate current regulating unit, a gate current measuring unit and a control element.

[0058] Specifically, the multi-mode imaging device 200 also includes a housing 240 , and the animal scanning control subsystem 210 , the static computed tomography imaging subsystem 220 and the photoacoustic imaging subsystem 230 are all disposed in the housing 240 .

[0059] Preferably, the photoacoustic imaging subsystem 230 includes an optical subsystem 231 for providing the excitation light required for photoacoustic imaging, an acoustic subsystem 232 for collecting multi-channel photoacoustic signals, and a photoacoustic coplanarity adjustment subsystem (not shown) for adjusting the incident angle of the excitation light to ensure that the optical signal and the acoustic signal remain coplanar. The optical subsystem 231 is mainly used to provide the excitation light required for photoacoustic imaging, which includes an excitation light source and a multi-wavelength optical focusing component. The acoustic subsystem 232 is mainly used to collect multi-channel photoacoustic signals, which is mainly composed of a high-frequency ultrasonic transducer array 2321 and a multi-channel data acquisition platform 2322. The photoacoustic coplanarity adjustment subsystem is mainly used to automatically adjust the incident angle of the excitation light to ensure that the light / acoustic signal always remains coplanar.

[0060] In a specific application, due to the non-uniformity of the periphery of the animal 400, the photoacoustic excitation (beam section) and the photoacoustic detection (sound beam section) cannot always be kept coincident during the overall scanning of the animal 400, resulting in a decrease in the signal-to-noise ratio, which greatly affects the quality of image reconstruction. In this embodiment, the photoacoustic coplanar adjustment subsystem monitors the exact size of the periphery of the animal 400 in real time through CT, calculates the exact position of the light incident plane, and then controls the light incident angle so that it is always coplanar with the ultrasound detection position, thereby ensuring high photoacoustic excitation-detection efficiency.

[0061] Preferably, the optical subsystem 231 includes an excitation light source, a lens group, an optical fiber bundle and an annular light bowl. The lens group is arranged between the excitation light source and the optical fiber bundle, and the optical fiber bundle is fixed on the annular light bowl and located between the lens group and the annular light bowl. The lens group, the optical fiber bundle and the annular light bowl together constitute a multi-wavelength optical focusing component. Among them, the optical fiber bundle is mainly used for coupling transmission of the excitation light; the annular light bowl is mainly used to fix the optical fiber bundle.

[0062] Preferably, the excitation light source is a high-energy fast nanosecond pulse optical parametric oscillator; the lens group includes a beam splitter, a plano-convex lens, a collimating lens and a focusing lens.

[0063] Preferably, the acoustic subsystem 232 includes a high-frequency ultrasonic transducer array 2321 for detecting acoustic signals and a multi-channel data acquisition platform 2322 for processing the detection signals of the high-frequency ultrasonic transducer array 2321. The high-frequency ultrasonic transducer array 2321 is mainly used to detect the excited acoustic signals, which can be specifically a ring structure. The multi-channel data acquisition platform 2322 is mainly used to process the detection signals. The multi-channel data acquisition platform 2322 can correspond to a separate data acquisition, amplification, filtering and other pre-processing channels for each array element of the high-frequency ultrasonic transducer array 2321, thereby realizing real-time high-speed data acquisition and pre-processing.

[0064] Preferably, the high-frequency ultrasonic transducer array 2321 includes a plurality of high-frequency ultrasonic transducers distributed in an array, and each high-frequency ultrasonic transducer corresponds to an array element of the high-frequency ultrasonic transducer array 2321. The high-frequency ultrasonic transducer is a multi-layer laminated structure, which includes an acoustic lens, a matching layer, a piezoelectric composite material layer, and an insulating backing layer stacked in sequence from front to back.

[0065] Preferably, the animal scanning control subsystem 210 includes a positioning structure 211 for positioning the animal 400 and an electromechanical control platform 212 for driving the positioning structure 211 and the animal 400 on the positioning structure 211 to move in a vertical direction. The positioning structure 211 is mainly used to accurately fix the animal 400, and the electromechanical control platform 212 is mainly used to control the effect of achieving the vertical movement of the animal 400.

[0066] Preferably, the image reconstruction and processing subsystem includes an image reconstruction group carrying an image reconstruction algorithm, an image calibration module carrying image correction and registration software, an image fusion module carrying multimodal image fusion software, and an information output module carrying information extraction and display software. The image reconstruction group specifically carries reconstruction algorithms for CT images and photoacoustic images.

[0067] The embodiment of the present invention provides a whole-body in vivo multimodal imaging technology and system for 400 animals with high spatial resolution, large imaging depth, extremely low side effects, and long-term monitoring. Among them, it has been proved through experiments that the static computed tomography imaging subsystem 220 has the advantages of fast imaging speed, high spatial resolution, and ultra-low radiation dose, while the photoacoustic imaging subsystem 230 has the characteristics of large imaging depth, high sensitivity and specificity, and it has been demonstrated through demonstration that the fusion of the static computed tomography imaging subsystem 220 and the photoacoustic imaging subsystem 230 is feasible.

[0068] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A multi-mode imaging system, characterized in that: It comprises a display, a multi-mode imaging device and a host electrically connected between the display and the multi-mode imaging device, wherein the host is provided with an image reconstruction and processing subsystem, and the multi-mode imaging device is provided with an animal scanning control subsystem, a static computed tomography imaging subsystem and a photoacoustic imaging subsystem, wherein the static computed tomography imaging subsystem comprises an electronic control circuit, a multi-beam carbon nanometer X-ray source array for generating X-rays required for static computed tomography scanning, a photon counting detector for computed tomography projection data acquisition and high-speed processing, and a power supply for supplying power to the multi-beam carbon nanometer X-ray source array, wherein the multi-beam carbon nanometer X-ray source array, the photon counting detector and the power supply are all electrically connected to the electronic control circuit; The animal scanning control subsystem includes a positioning structure for positioning the animal and an electromechanical control platform for driving the positioning structure and the animal on the positioning structure to move in a vertical direction; The multi-beam carbon nanometer X-ray source array includes a plurality of carbon nanometer X-ray sources distributed in an array, and the carbon nanometer X-ray source includes a vacuum chamber, a carbon nanometer field emission cathode, a gate, a focusing electrode and an anode. The carbon nanometer field emission cathode, the gate, the focusing electrode and the anode are all arranged in the vacuum chamber, and the anode is arranged at an interval and tilted above the carbon nanometer field emission cathode, and the inclination angle formed by the anode relative to the horizontal plane is 5° to 15°, the gate and the focusing electrode are both arranged between the carbon nanometer field emission cathode and the anode, and the gate is located between the focusing electrode and the carbon nanometer field emission cathode, and the vacuum chamber is provided with an X-ray exit window located next to the anode.

2. The multi-mode imaging system according to claim 1, characterized in that: The carbon nanometer field emission cathode comprises a substrate and a cold cathode material layer arranged on the surface of the substrate.

3. The multi-mode imaging system according to claim 2, characterized in that: The substrate is a metal substrate or a silicon wafer coated with a metal coating; and / or, The material of the cold cathode material layer is carbon nanotube, or graphene, or a mixture of carbon nanotube and graphene.

4. The multi-mode imaging system according to any one of claims 2 to 3, characterized in that: The number of the carbon nano-X-ray sources is 90-180; and / or, Each of the carbon nano-X-ray sources is distributed in a circular array or a polygonal array; and / or, The X-ray exit window is an aluminum window or a beryllium window; and / or, The vacuum degree of the vacuum chamber is 10 -6 mmHg~10 -11 mmHg; and / or, The grid comprises a support and a grid disposed on the support, wherein the grid has an opening for electrons to pass through; and / or, The relative distances among the carbon nanometer field emission cathode, the grid electrode, the focusing electrode and the anode are adjusted by insulating spacers.

5. The multi-mode imaging system according to claim 1, wherein: The photoacoustic imaging subsystem includes an optical subsystem for providing excitation light required for photoacoustic imaging, an acoustic subsystem for collecting multi-channel photoacoustic signals, and a photoacoustic coplanarity adjustment subsystem for adjusting the incident angle of the excitation light to ensure that the optical signal and the acoustic signal remain coplanar.

6. The multi-mode imaging system according to claim 5, characterized in that: The optical subsystem includes an excitation light source, a lens group, an optical fiber bundle and an annular light bowl. The lens group is arranged between the excitation light source and the optical fiber bundle. The optical fiber bundle is fixed on the annular light bowl and is located between the lens group and the annular light bowl.

7. The multi-mode imaging system according to claim 5 or 6, characterized in that: The acoustic subsystem includes a high-frequency ultrasonic transducer array for detecting acoustic signals and a multi-channel data acquisition platform for processing the detection signals of the high-frequency ultrasonic transducer array.

8. The multi-mode imaging system according to claim 7, characterized in that: The high-frequency ultrasonic transducer array includes a plurality of high-frequency ultrasonic transducers distributed in an array. The high-frequency ultrasonic transducer is a multi-layer stacked structure, which includes an acoustic lens, a matching layer, a piezoelectric composite material layer, and an insulating backing layer stacked in sequence from front to back.

9. The multi-mode imaging system according to any one of claims 1 to 3 or 5 or 6, characterized in that: The image reconstruction and processing subsystem includes an image reconstruction model group carrying an image reconstruction algorithm, an image calibration module carrying image correction and registration software, an image fusion module carrying multimodal image fusion software, and an information output module carrying information extraction and display software.

Images