CN110676145A

CN110676145A - Multi-focus X-ray bulb tube and multi-focus X-ray imaging system

Info

Publication number: CN110676145A
Application number: CN201911045237.0A
Authority: CN
Inventors: 王宗朋; 成富平; 沈爱祥
Original assignee: SHENZHEN ANGELL TECHNOLOGY Co Ltd
Current assignee: SHENZHEN ANGELL TECHNOLOGY Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-01-10

Abstract

The invention is suitable for the field of medical equipment, and provides a multifocal X-ray bulb tube and a multifocal X-ray imaging system. The multi-focus X-ray bulb tube comprises a tube sleeve, a tube core and a bearing end, wherein the tube core and the bearing end are positioned in the tube sleeve; a cathode end and an anode end are placed in the tube core, a power supply interface assembly is arranged on the tube sleeve, and the power supply interface assembly comprises at least one cathode power supply interface connected with the cathode end and at least two anode power supply interfaces connected with the anode end; the bearing end comprises a rotating shaft, and the anode end is arranged on the rotating shaft; the anode end comprises at least two anode targets which can rotate along with the rotating shaft, and the anode targets are connected with the anode power supply interfaces in a one-to-one correspondence manner; the cathode terminal includes at least one electron generation source connected to the cathode power supply interface, each electron generation source emitting electrons to a corresponding anode target for bombardment to radiate X-rays. The multi-focus X-ray bulb tube can replace a plurality of single-focus bulb tubes, and the production and maintenance cost is reduced.

Description

Multi-focus X-ray bulb tube and multi-focus X-ray imaging system

Technical Field

The invention belongs to the field of medical equipment, and particularly relates to a multifocal X-ray bulb tube and a multifocal X-ray imaging system.

Background

The X-ray tube is a core component which is operated under high voltage to generate X-rays and comprises two electrodes: one is a filament or other electron generating source for generating and emitting electrons, acting as a cathode, and the other is a target for receiving high-speed electron bombardment, acting as an anode, both of which are sealed in a high-vacuum glass or metal envelope. According to different purposes, the X-ray tube can be divided into a medical X-ray tube and an industrial X-ray tube, wherein the medical X-ray tube is mainly used for diagnosis and treatment, and the industrial X-ray tube is mainly used for nondestructive testing, structural analysis, spectral analysis, negative film exposure and the like of materials.

The position of an anode bombarded by electrons in an X-ray tube can be regarded as a focus, the existing X-ray tube is of a single-focus structure, and in some occasions requiring multi-focus exposure, such as diagnosis and treatment of cardiovascular and cerebrovascular diseases, a plurality of single-focus X-ray tubes are usually used, each single-focus X-ray tube needs to be provided with a set of control system and image processing system, the exposure time is long, motion artifacts are easy to occur, the cost is high, and the integration degree is limited.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is how to implement multi-focus exposure in a low-cost and high-integration manner.

In order to solve the above technical problem, in a first aspect, an embodiment of the present invention provides a multifocal X-ray tube, including a tube casing, a tube core located inside the tube casing, and a bearing end, where an inside of the tube core is a vacuum environment; a cathode end and an anode end are placed in the tube core, a power supply interface assembly is arranged on the tube sleeve, and the power supply interface assembly comprises at least one cathode power supply interface connected with the cathode end and at least two anode power supply interfaces connected with the anode end; the bearing end comprises a rotating shaft, and the anode end is mounted on the rotating shaft; the anode end comprises at least two anode targets which can rotate along with the rotating shaft, and the anode targets are connected with the anode power supply interfaces in a one-to-one correspondence manner; the cathode end comprises at least one electron generation source connected with the cathode power supply interface, and each electron generation source emits electrons to the corresponding anode target to bombard so as to radiate X rays.

Further, the multi-focus X-ray bulb tube also comprises a heat dissipation circulating system; the heat dissipation circulation system includes: the heat dissipation device comprises a liquid inlet, a liquid outlet, heat dissipation liquid and a circulation control device; the circulation control device is used for controlling the heat dissipation liquid to circularly enter and exit between the liquid inlet and the liquid outlet; the tube core is soaked in the heat dissipation liquid.

Further, the at least two anode targets are all installed on the same rotating shaft, the rotating shaft is a metal rotating shaft, and the metal rotating shaft and the anode targets are at the same potential.

Further, the number of the die is at least two; each die includes one of said anode targets and one of said electron-generating sources, the anode targets in each die being mounted on said rotating shaft.

Further, the number of the die is at least one; each die comprises two anode targets and an electron generating source, wherein the electron generating source is positioned between the two anode targets and used for emitting electrons to the two anode targets to bombard so as to radiate X rays; all anode targets are mounted on the rotating shaft.

Furthermore, each anode power supply interface is used for grounding, and each cathode power supply interface is used for connecting different negative high voltages.

Furthermore, each anode power supply interface is used for connecting different positive high voltages, and each cathode power supply interface is used for grounding.

In a second aspect, an embodiment of the present invention further provides a multi-focus X-ray imaging system, including:

a multifocal X-ray tube of the first aspect;

the frame is used for bearing the multi-focus X-ray bulb tube and driving the multi-focus X-ray bulb tube to rotate in a preset multi-dimensional degree of freedom;

the high-voltage generator is connected with an anode power supply interface or a cathode power supply interface of the multi-focus X-ray bulb tube and used for providing positive high voltage for the anode power supply interface or negative high voltage for the cathode power supply interface; the rotating shaft is also connected with the bearing end and used for supplying power to the bearing end so as to control the rotating shaft to rotate;

the beam splitter is arranged on the light outlet side of the multi-focus X-ray bulb tube, is provided with an opening with adjustable size, shape and position, and is used for limiting the distribution of X rays by controlling the opening;

the plurality of filters are positioned on the light outlet side of the beam splitter, are respectively and independently positioned on the light paths of the corresponding focuses, have different filtering materials and thicknesses, and are used for filtering the energy spectrum of the X rays of the corresponding light paths and only allow the X rays of the energy spectrum in a target range to irradiate an object;

the detector is used for converting the X-rays penetrating the irradiation object into digital signals and outputting the digital signals;

the image processing device is connected with the detector and used for processing the signal output by the detector to obtain a three-dimensional image;

and the controller is connected with the high-voltage generator, the beam splitter, the detector and the image processing device and is used for receiving input exposure parameters and cooperatively controlling the high-voltage generator, the beam splitter, the detector and the image processing device according to the exposure parameters.

Further, all focuses of the multi-focus X-ray bulb tube are linearly arranged; the controller is also used for controlling the exposure of all focuses of the multi-focus X-ray bulb tube simultaneously or sequentially.

Further, the inclination angle formed by each focal point of the multi-focus X-ray tube and the center of the detector ranges from-30 degrees to 30 degrees.

The multi-focus X-ray bulb tube provided by the invention comprises a plurality of anode targets, the multi-anode targets can be flexibly designed into various forms, multi-view exposure can be rapidly completed at one time, performance parameters which can be provided by a plurality of single-focus bulbs are provided, the radiation dose is reduced while the exposure time is greatly reduced, the X-ray rapid inspection is convenient, the motion artifacts caused by long exposure are reduced, and simultaneously, the emission of dual-energy and multi-energy X-rays can be supported, and the image quality is improved. Therefore, the multi-focus X-ray bulb tube provided by the invention is highly integrated, can completely replace a plurality of single-focus bulbs, and reduces the production and maintenance cost.

Drawings

FIG. 1A is a block diagram of a multifocal X-ray tube provided in accordance with a first embodiment of the present invention;

FIG. 1B is another block diagram of a multifocal X-ray tube provided in accordance with a first embodiment of the present invention;

FIG. 2 is a block diagram of a multi-focus X-ray imaging system provided in accordance with a second embodiment of the present invention;

FIG. 3 is a schematic diagram showing the comparison of the size of the detector required for single focus exposure and dual focus exposure provided by the second embodiment of the present invention;

FIG. 4 is a schematic view of a linear multifocal exposure provided by a second embodiment of the present invention;

fig. 5 is a flowchart of image data acquisition for a multi-focus exposure according to a second embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 1A and 1B are two structural diagrams of a multifocal X-ray tube according to a first embodiment of the present invention, and please refer to fig. 1A and 1B together, the multifocal X-ray tube includes a tube sleeve 1, a tube core 2 located inside the tube sleeve 1, and a bearing end 3, and the inside of the tube core 2 is a vacuum environment. The tube core 2 is internally provided with a cathode end and an anode end, and the tube sleeve 1 is provided with a power supply interface assembly (not shown in the figure) which comprises at least one cathode power supply interface connected with the cathode end and at least two anode power supply interfaces connected with the anode end. The anode side includes at least two anode targets 22 rotatable with a rotating shaft 32 and the cathode side includes at least one electron generating source 21 connected to a cathode power interface.

The tube sleeve 1 refers to a bulb shell of multi-focus X-ray and is connected with an external high-pressure system. The die 2 may be made of silicon having high temperature resistance, high dielectric strength, and a small coefficient of expansionBased on boric acid hard glass or all-metal compositions, resistant to more than 19.6m/s if required²Mechanical vibrations, or impulse shocks (i.e. 2 times the acceleration of gravity), will give preference to the metal shell. The tube core 2 is used for supporting the cathode terminal, the anode terminal and maintaining the vacuum degree in the tube, and the vacuum degree is kept to be 133.322 multiplied by 10 under the general condition^-7Pa below to ensure normal heating of the filament and bombardment speed of electrons.

The bearing end comprises a rotor, a stator and a rotating shaft 3, the rotor is usually a copper cylinder on the bearing and is driven by induced electromotive force of a motor 4, a thick anode target 22 is arranged on the rotating shaft 3 of the bearing, the stator is usually sleeved outside a tube core of the multi-focus X-ray tube, a rotating magnetic field is established by coil current flowing through a stator winding to drive the rotor to rotate, and the rotating shaft 3 rotates along with the rotor.

Particularly, at least two anode targets 22 are all installed on the same rotating shaft 3, so that the manufacturing cost is saved, the rotating shaft 3 can be a metal rotating shaft, and the metal rotating shaft and the anode targets 22 have the same potential, so that the trouble of arranging an insulating isolation layer is avoided.

As described above, the anode end includes at least two anode targets 22 rotatable with the rotating shaft 3, specifically, the two anode targets 22 shown in fig. 1A are respectively located in two independent dies 2, or the two anode targets 22 shown in fig. 1B are both located in the same die 2, and the at least two anode targets 22 are connected to the anode power supply interfaces in a one-to-one correspondence manner. Each electron generation source 21 at the cathode end emits electrons to the corresponding anode target 22 to bombard and radiate X-rays, and generally, only one electron generation source 21 is provided in each die 2, and each electron generation source 21 shown in fig. 1A emits electrons to one anode target 22, or each electron generation source 21 shown in fig. 1B emits electrons to two anode targets 22.

The electron generating source or sources 21 in the cathode terminal can be a conventional hot cathode, commonly known as a filament (tungsten, molybdenum), or a field-effect electron-emitting cold cathode, commonly known as a carbon nanotube, silicon nanoneedle, or the like.

The cathode terminal further includes a cathode cover for supporting the electron generation source 21 while shielding high-speed electrons reflected from the anode target 22 to protect the cathode terminal. And a grid structure is arranged between the cathode end and the anode end, is close to the cathode end and is directly used for closing and opening electron beam current generated by the electron generation source 21, so that soft X rays can be effectively shielded. The cathode end is also provided with a focusing cover, the electron beams generated by the electron generating source 21 are focused in one direction under the action of an electric field or a magnetic field, the divergence is reduced, the bombardment efficiency is improved, the size of a focal point and defocusing artifacts are effectively reduced, a sharp focal spot can be generated through good focusing, and unnecessary heat loss and soft rays are reduced.

The anode target 22 is used for receiving electron bombardment radiation X-rays and radiating heat, can be designed into a cylindrical or conical anode target according to an electron emission track, adopts elements with high atomic number such as tungsten or molybdenum on the material, usually uses tungsten as the target surface material of the anode target 22, and then is evaporated with an additional rhenium coating to increase the surface characteristic so as to reduce pitting corrosion and cracking, and the target surface of the anode target 22 made of the tungsten material, a rotor copper cylinder, an intermediate connecting part of iron-nickel drilling alloy with similar thermal expansion coefficient and a glass shell (or a metal shell) are sealed and connected to the outside of the multi-focus X-ray bulb tube.

The inclination angle α or β of the target surface of the anode target 22 in fig. 1A is in the range of 8 ° to 15 °. In order to reduce the geometrical ambiguity and obtain a clear image, a small X-ray focus is required, i.e. a small anode target angle is used, but this is not favorable for heat diffusion, and the anode target is easily overheated and is easily aged in advance. On the other hand, the inclination angle of the target surface of the anode target 22 cannot be too large, because an increase in the inclination angle will increase the effective focal area, and an excessively large X-ray focal point will cause image blurring. Therefore, the reasonably designed anode target surface angle can effectively eliminate X-rays generated by non-focuses, and the sharpness of the image is improved.

The structural relationship between the cathode terminal and the anode terminal is very flexible, and may be a structure including one cathode and one anode in the die 2 shown in fig. 1A, or a structure including one cathode and two anodes in the die 2 shown in fig. 1B. It should be noted that fig. 1A and fig. 1B each only show two anode targets 22 for representing two focal points, and a multi-focal-point structure can be obtained according to the embodiment, if multiple focal points are implemented based on fig. 1A, there are at least two die 2, each die 2 includes one anode target 22 and one electron generation source 21, and the anode targets 22 in each die 2 are mounted on the rotating shaft 32; if multiple focal points are realized based on fig. 1B, there is at least one die 2, each die 2 includes two anode targets 22 and one electron generation source 21, the electron generation source 21 is located between the two anode targets 22 and is used for emitting electrons to the two anode targets 22 for bombardment so as to radiate X-rays, and the two anode targets 22 are both mounted on the rotating shaft 32.

The high speed movement of electrons from the electron generating source 21 to the anode target 22 involves electron beam generation, electron beam deflection and electron beam focusing. The electron generating source 21 may employ a hot cathode such as a tungsten filament of a solenoid shape, and may also employ a cold cathode such as a carbon nanotube. The cathode end can have one or more electron generation source 21 level or vertical arrangement, to hot cathode, different filaments can be in the same place in series, also can be through relay switch control filament length, and then control electron emission density, for protecting the filament better, at the cathode end with the cathode casing surround the cathode, prevent that secondary electron from reflecting to the filament and lead to filament short circuit fusing. For cold cathodes, the electron beam density is optionally controlled by a gate switch. Electrons are emitted from the electron generation source 21 to the anode target 22, and focusing of electrons in an emission trajectory is particularly important, especially in the case of a large current. Typical short distances are from 10 mm to 20 mm, and for high kV the electric field distance may reach 100 mm. The electron beam can be regulated by an electric field and a deflection magnetic field generated by a coil, so that the central position and the size of an X-ray focal spot are adjusted.

Further, the multi-focus X-ray bulb tube further comprises a heat dissipation circulating system, and the heat dissipation circulating system comprises: the cooling device comprises a liquid inlet 11 and a liquid outlet 12 which are positioned on the pipe sleeve 1, cooling liquid filled in the pipe sleeve 1 and a circulation control device, wherein the circulation control device is used for controlling the cooling liquid to circularly flow in and out between the liquid inlet 11 and the liquid outlet 12 so as to ensure that the pipe core 2 is soaked in the cooling liquid which circularly flows.

The heat dissipation circulation system can adopt oil circulation, and heat generated inside the tube core 2 is taken away in time through cooling oil. The anode targets 22 share a set of heat dissipation circulation system, so that the volume of the bulb tube can be reduced, and the cost is saved. As can be seen from fig. 1A and 1B, the tube core 2 is directly immersed in the cooling liquid, the heat emitted from the anode target 22 can be directly conducted into the cooling liquid through the shell of the tube core 2, and the heat of the anode target 22 is quickly taken away by the circularly flowing cooling liquid in time. The heat of the anode target surface of the traditional bulb tube can be transferred to the heat dissipation oil outside the glass shell only through a heat conduction mode of heat radiation, the heat dissipation mode cannot support high-power exposure, the heat capacity of the bulb tube is increased rapidly due to the fact that heat cannot be dissipated timely under the condition that exposure tasks are multiple, and if the exposure is not stopped forcibly in time, the bulb tube is aged in advance and even scrapped.

In the electron beam generation stage, if high power exposure is used, the electron generation source 21 emits electrons in a saturated state, and softening, shifting and fusing of the filament due to cathode overheating and overcurrent easily occur, and in order to reduce the electron emission load borne by a single cathode, a multi-cathode structure, that is, the structure in fig. 1A, may be used. In FIG. 1A, a pair of electron generating sources 21 are respectively located on both sides of the anode target, and independent circuits are provided to control the emission of electrons, so as to support the emission of electrons simultaneously or in a certain order, thereby avoiding premature loss caused by the high load emission of electrons from a single electron generating source 21. At the same time, there are two independent bombardment sites on the target surface of different anode targets 22, and thus there may be two different sized, different positioned foci. The spacing between the two anode targets 22 is d, and can typically be 5cm, 10cm or 15 cm. The heat generated by the anode target 22 is taken away in time by using the closed cooling liquid in the middle, and a good heat dissipation effect is achieved. Considering that the two anode targets 22 are independent, the target face angle, bombardment position and bombardment electron density can be controlled independently on each side, flexibly meeting the practical application. The structure supports single focus work and multi-focus simultaneous work or work according to a certain sequence, can meet the requirement of a large field of view (FOV) (FieldOfView), and is convenient to use for tomography.

The electrons emitted from the electron generating source 21 need to be accelerated at a high voltage to reach the anode target 22, and the high voltage is applied in two ways:

first, each anode power supply interface is used for grounding, and each cathode power supply interface is used for connecting different negative high voltages.

And secondly, each anode power supply interface is used for connecting different positive high voltages, and each cathode power supply interface is used for grounding.

The first type is preferably selected during specific implementation, the anode end is grounded through the anode power supply interface, negative high voltage is only added to the cathode end, and the power supply circuit only needing the cathode end is designed, so that the control is simple. In consideration of the requirement of dual energy in practical application, the anode terminals can be grounded, and the electron generation sources 21 of the cathode terminals are applied with different negative high voltages, so that the X-rays with different energies can be emitted simultaneously.

A second embodiment of the present invention provides a multifocal X-ray imaging System, as shown in fig. 2, including a multifocal X-ray tube 201, a high voltage generator 202, a beam splitter 203, several filters 204, a detector 205, an image processing device 206, a controller 207, and a rack, in addition, Power supply boards of the rack, the beam splitter 203, the filters 204, and the high voltage generator 202 are output by a Power Distribution System (PDS) of the System to ensure stable operation. The concrete description is as follows:

the multi-focus X-ray tube 201 is the multi-focus X-ray tube provided in the first embodiment, and is not described in detail.

The frame is used for bearing the multi-focus X-ray bulb 201 and driving the multi-focus X-ray bulb to rotate in a preset multi-dimensional degree of freedom. The frame has multi-dimensional freedom, and can support the bulb and change the position of the bulb.

The high voltage generator 202 is connected with an anode power supply interface or a cathode power supply interface of the multi-focus X-ray bulb tube 201 and is used for providing positive high voltage for the anode power supply interface or negative high voltage for the cathode power supply interface; and the bearing end is also connected with the rotating shaft and used for supplying power to the bearing end to control the rotation of the rotating shaft. The functions of the high voltage generator 202 include changing an ac power source into a dc high voltage, controlling the rotation of the anode rotor of the bulb, controlling the current of the filament, receiving a control command of the system, and the like. The alternating current is subjected to common rectification filtering, high-frequency inversion and high-voltage rectification filtering to obtain high-voltage direct current. The main control board of the high voltage generator 202 directly interacts with the controller 207, and for a specific region of interest (ROI), specific kV, mA and the size and center of the filter 204 and the beam splitter 203 are required to obtain the best image quality at the lowest dose condition.

The beam splitter 203 is disposed on the light exit side of the multifocal X-ray tube 201 and has an opening with adjustable size, shape and position for limiting the distribution of X-rays by controlling the opening. The beam forming material is usually lead, and the common shapes are rectangle, circle, polygon and the like. For the rectangular beam splitter, the rectangular beam splitter consists of four independent metal blocking pieces, the central position and the opening size in the X direction and the Y direction are determined, and the metal blocking pieces are controlled by a stepping motor, a position sensor and an encoder, can accelerate, decelerate and move at a constant speed in real time, and can feed back the actual position. As a core sub-component of the multi-focus X-ray imaging system, especially applied to the diagnosis and treatment of cardiovascular and cerebrovascular diseases, the beam splitter 203 has high requirements on usability, interactivity, real-time performance, accuracy, reliability and safety, interacts with the controller 207, and supports real-time communication, command control and state information.

And the filters 204 are positioned on the light outlet side of the beam splitter 203, each filter 204 is independently positioned on the light path of the corresponding focus, and the filters 204 are made of different materials and different thicknesses and are used for performing energy spectrum filtering on the X-rays of the corresponding light path and only allowing the X-rays with the energy spectrum within a target range to irradiate on the object. Considering that there is a certain space interval between the multiple focuses, the filters 204 of different thicknesses, different materials, and different shapes are added in different directions, and the filters 204 preferentially filter the soft X-rays with low energy. Two or more focuses have independent geometric light paths, so that different filters 204 are arranged on the light path of each focus, X-rays with different energy spectrums can be obtained, and diversified practical applications are met.

The detector 205 is used for converting the X-rays penetrating the irradiation object into digital signals and outputting the digital signals. The shadowgraph and penumbra regions on the detector are different, taking into account the different photon distributions of the monofocal and multifocal spots. Under the condition of obtaining the same exposure field of view (FOV), the shadowed area corresponding to multiple foci is smaller than that of single focus, as shown in fig. 3, that is, the detector size required for multiple foci is smaller than that of single focus for the same exposure object. According to the similar trigonometric relationship, the larger the source-image distance (SID), the larger the size difference of the detectors corresponding to the multiple focal points and the single focal point. Therefore, in practical applications where a large FOV and a large SID are used, detector 205 need not be as large as a conventional single focus system detector, saving detector manufacturing and usage costs.

The detectors 205 are classified according to the collection mode and may be classified into energy integration type detectors such as sodium iodide (NaI), cesium iodide, and lanthanum bromide, and photon counting type detectors such as cadmium telluride (CdTe), Cadmium Zinc Telluride (CZT), silicon (Si), and gallium arsenide (GaAs). The array type detector can be classified into a CCD detector, an amorphous silicon flat panel detector and an amorphous selenium flat panel detector according to the arrangement mode.

The CCD detector and the amorphous silicon detector belong to indirect conversion detectors, and the time for signal collection and processing is long, so that the operation and imaging speed of the system are influenced. The CCD detector chip is smaller than the scintillator, the number of photons reaching the chip is reduced, noise is increased, image quality is reduced, and geometric distortion of the image and light scattering are caused. The amorphous silicon flat panel detector can better meet the higher requirement on the image density resolution, but has inherent defects of solid detectors such as dead spots, drift and the like. The amorphous selenium flat detector utilizes X photons to change into an electric signal on a selenium coating layer, and belongs to a direct detection device. The processing time is short, the spatial resolution is good, but the selenium layer is sensitive to temperature and has poor environmental adaptability.

Typically, for flat panel detectors, a grid is also placed in front of the detector 205 to filter the scattered X-rays. The analog-to-digital converter is used for converting an analog signal into a digital signal and facilitating computer processing, scintillating crystals and converting X rays into visible light, the photodiode is used for converting the visible light into electron hole pairs, the thin film transistor is used for collecting excited charge carriers, and then the electric signals are transmitted to the analog-to-digital converter through the data line and the charge amplifier.

The image processing device 206 is connected to the detector 205, and is configured to process the signal output by the detector 205 to obtain a three-dimensional stereoscopic image. The image processing device 206 is a host of the whole system, and can be realized by a computer PC, and sends exposure parameters and collects and processes collected data through a software interactive interface, so as to store Dicom images and raw data (raw data). The host computer provides a computing system that performs pre-processing and post-processing after obtaining raw data provided by the detector 205. The preprocessing includes spectral correction using a correction table, filtering, denoising, smoothing, enhancement, and the like. The exposure field of view often exceeds the exposure object area, i.e. the sensing area of the detector often receives X-rays without any attenuation, in order to better display the air area around the image and to take care of the interested middle area, different histogram stretching and gray normalization are usually performed on the gray values of different areas of the image, and the window width and the window level are adjusted to be reasonable. Image post-processing includes utilizing two-dimensional image segmentation, feature extraction, dual-energy subtraction, three-dimensional synthesis, and the like. Two-dimensional images obtained by multiple focuses at different exposure angles are combined into a three-dimensional image according to a certain sequence, so that more visual and comprehensive digital information is provided for a user. The host also supports managing patient information, displaying images, revisiting at any time, etc. via a software interface.

The controller 207 is connected to the high voltage generator 202, the beam splitter 203, the detector 205, and the image processing apparatus 206, and is configured to receive input exposure parameters, and cooperatively control the high voltage generator 202, the beam splitter 203, the detector 205, and the image processing apparatus 206 according to the exposure parameters. The user can control the exposure state by entering the exposure parameters in the controller 207, which controller 207 is the most important messaging platform. The controller 207 interacts with the high voltage generator 202, the detector 205 and software in real time, sending and receiving command messages and status information for the system. The controller 207 is based on the CAN bus control, and CAN monitor and control the position of each metal baffle, the selection state of the filter, the maximum moving range of the baffle, the maximum step length of one-time movement, the maximum minimum moving speed, the minimum moving precision, the moving mode (coarse adjustment mode and fine adjustment mode, manual mode and electric mode) in real time according to the configuration of the stepping motor and the encoder, and is also provided with necessary warning prompt and error alarm mechanisms to prevent the baffle from collision and overrun.

In practical application, according to a specific region of interest, the focal points of the tube are distributed longitudinally, as shown in fig. 4, the focal points of the multi-focal X-ray tube are arranged linearly, and the controller 207 controls the focal points to be simultaneously exposed in a static condition at one time, so that the exposure time is saved, the motion artifacts are reduced, and the image definition is improved, and of course, the controller 207 can also control the focal points to be sequentially exposed according to a preset sequence. The SID is adjusted accordingly to obtain the best exposure position according to the different FOV. Typically, the linear arrangement of the focal points has a tilt angle in the range of-30 degrees to 30 degrees from the center of the detector 205, sufficient for tomographic and 3D synthesis.

For dual and multi-energy imaging, the image data acquisition flow following the multi-focus exposure is shown in fig. 5. And (3) initial exposure, acquiring a first image by using preset tube current and high voltage, and acquiring an image again by taking optimized tube current and high voltage during next exposure. It is noted that each focal point operates independently, and may be exposed to different high-pressure conditions simultaneously or sequentially without being exposed to different high-pressure conditions simultaneously. Thereby acquiring X-rays with different energies. Clinically, when X-rays with high and low energies penetrate a human body, the difference between the X-rays is small on soft tissues and large on bone tissues. The low-energy spectrum (40-50 KeV) is mainly photoelectric effect, and the high-energy spectrum (80-100 KeV) is mainly Compton scattering, so that the imaging resolution of soft tissue is highest near 35KeV energy, and the imaging resolution of bone tissue is highest near 75KeV energy. The multi-focus X-ray imaging system not only can emit two X-rays with different energies simultaneously through the double focuses to achieve dual-energy subtraction, but also can emit multiple X-rays with different energies simultaneously through the multi-focus to achieve multi-energy imaging. For multi-energy imaging, not only can provide quite accurate bone density value, but also can further distinguish components of muscle and fat in soft tissues, calculate the body-fat ratio of a tested person and directly apply to sports medicine.

In summary, for X-ray examination, the radiation dose and the image quality are the most concerned indexes of the user, and the multi-focus X-ray tube provided by the embodiment of the invention can simultaneously emit dual-energy or multi-energy X-rays, thereby optimizing the image quality and improving the material resolution capability. The exposure advantage that can not be provided as single light source is fully exerted, compared with a single-focus bulb tube, the time required by single exposure is effectively shortened, the multi-angle exposure speed is high, and the motion artifact caused by over-long exposure is reduced. Therefore, the invention has the advantages of multi-function of cost reduction, flexible exposure control and effective reduction of radiation dose. By simultaneous or sequential multifocal exposure, the maximum time for continuous exposure can be greatly extended, supporting high-load exposure applications. In addition, one-click free selection of multi-focus exposure under different exposure modes is supported, such as multi-focus simultaneous exposure or sequential exposure, and the method is simple and easy to operate. A plurality of single-focus spherical tubes are not needed, the production and maintenance cost is reduced, and the device has the advantages of multiple purposes and high integration level.

It can be seen that the present invention is directed to a variety of applications, and the multi-focus X-ray imaging system provided by the all-in-one integration technology achieves the purpose of one machine for multiple purposes, and reduces the production and maintenance costs. The multi-focus X-ray imaging system may be suitable for multi-kV range applications. Static exposure is fast, and has the core advantages that CT does not have in the aspects of reducing radiation dose, reducing exposure time and eliminating motion artifacts. The system provides independent and multifunctional accurate exposure parameters, can be used for shooting of different positions, large-field exposure, tomography and the like, can also be used for industrial 3D photography, and completes high-load inspection work.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The multifocal X-ray bulb tube is characterized by comprising a tube sleeve, a tube core and a bearing end, wherein the tube core is positioned in the tube sleeve, and the interior of the tube core is in a vacuum environment; a cathode end and an anode end are placed in the tube core, a power supply interface assembly is arranged on the tube sleeve, and the power supply interface assembly comprises at least one cathode power supply interface connected with the cathode end and at least two anode power supply interfaces connected with the anode end; the bearing end comprises a rotating shaft, and the anode end is mounted on the rotating shaft;

the anode end comprises at least two anode targets which can rotate along with the rotating shaft, and the anode targets are connected with the anode power supply interfaces in a one-to-one correspondence manner; the cathode end comprises at least one electron generation source connected with the cathode power supply interface, and each electron generation source emits electrons to the corresponding anode target to bombard so as to radiate X rays.

2. The multifocal X-ray tube of claim 1 wherein said multifocal X-ray tube further comprises a heat dissipation cycle system; the heat dissipation circulation system includes: the heat dissipation device comprises a liquid inlet, a liquid outlet, heat dissipation liquid and a circulation control device; the circulation control device is used for controlling the heat dissipation liquid to circularly enter and exit between the liquid inlet and the liquid outlet; the tube core is soaked in the heat dissipation liquid.

3. The multifocal X-ray tube of claim 1 wherein said at least two anode targets are each mounted on the same axis of rotation, said axis of rotation being a metallic axis of rotation and said metallic axis of rotation being at the same potential as the anode targets.

4. The multifocal X-ray tube of claim 1 wherein said tube cores are at least two; each die includes one of said anode targets and one of said electron-generating sources, the anode targets in each die being mounted on said rotating shaft.

5. The multifocal X-ray tube of claim 1 wherein said tube core is at least one; each die comprises two anode targets and an electron generating source, wherein the electron generating source is positioned between the two anode targets and used for emitting electrons to the two anode targets to bombard so as to radiate X rays; all anode targets are mounted on the rotating shaft.

6. The multifocal X-ray tube of claim 1 wherein each of said anode power supply ports is adapted for grounding and each of said cathode power supply ports is adapted for receiving a different negative high voltage.

7. The multifocal X-ray tube of claim 1 wherein each of said anode power supply ports is adapted to receive a different positive high voltage and each of said cathode power supply ports is adapted to be grounded.

8. A multi-focal X-ray imaging system, comprising:

a multifocal X-ray tube as claimed in any one of claims 1 to 7;

9. The multifocal X-ray imaging system of claim 8 wherein the foci of said multifocal X-ray tube are linearly arranged; the controller is also used for controlling the exposure of all focuses of the multi-focus X-ray bulb tube simultaneously or sequentially.

10. The multifocal X-ray imaging system of claim 8 wherein each focal point of said multifocal X-ray tube has an inclination from-30 degrees to 30 degrees from the center of said detector.