Tomographic imaging device and method based on multi-focus X-ray source

Abstract

The invention relates to the technical field of X-ray imaging, and discloses a tomography device and method based on a multi-focus X-ray source, and the device comprises a control system which is used for controlling the multi-focus X-ray source to carry out the longitudinal scanning of a detected object; n ray tubes which are transversely distributed are arranged on the multi-focus X-ray source, each ray tube internally comprises an independent cathode and an independent anode, and the cathode and the anode are used for triggering and generating multi-view X-rays; the detector is used for receiving the X-rays penetrating through the detected object and converting the X-rays into multi-view projection data; and the image processing system is connected with the detector and is used for processing the multi-view projection data based on a tomography reconstruction algorithm to obtain tomography data of the detected object and a three-dimensional reconstruction model. The multi-focus ray source and the detector which are horizontally and transversely arranged synchronously move for scanning, multi-view-angle and high-efficiency whole-body tomography data acquisition is achieved, and the requirement for rapid, accurate and whole-body tomography imaging is met in combination with a tomography reconstruction algorithm.

Description

Technical Field

[0001] This application relates to the field of X-ray imaging technology, and more specifically, to a tomographic imaging apparatus and method based on a multifocal X-ray source. Background Technology

[0002] X-ray is a device that uses X-ray technology to perform non-destructive testing and inspection of objects. It generates high-energy X-ray radiation, which is then directed onto the object being inspected. A corresponding detector receives and converts this radiation into an image signal, generating a high-resolution X-ray image. X-ray inspection machines are widely used in industry, medicine, security, and other fields, and can be used to inspect defects, structures, and properties of various materials and products, including metals, plastics, ceramics, and composite materials.

[0003] Existing X-ray imaging systems typically employ a combination of a single-focus X-ray source and a flat-panel or linear array detector. Projected images are acquired through a single exposure, followed by tomographic imaging using reconstruction algorithms. However, a single-focus X-ray source can only provide projection data from a single viewpoint, failing to achieve multi-view tomographic imaging and resulting in numerous shortcomings when reconstructing volumetric images. For example, single-view projection data is prone to information loss and ambiguity when reconstructing 3D images, making it difficult to accurately reconstruct the internal structure of objects. Furthermore, traditional single-focus X-ray sources require mechanical movement of the object or the X-ray source to obtain projection data from different angles during tomographic imaging. This not only increases imaging time but can also lead to motion artifacts, affecting image quality. Moreover, due to the limitations of single-focus X-ray sources, the imaging system cannot always get sufficiently close to the object being imaged, resulting in unnecessary increases in radiation dose. These shortcomings limit the effectiveness and accuracy of X-ray imaging technology in some complex scenarios. Summary of the Invention

[0004] To address the aforementioned technical problems, this application discloses a tomographic imaging device and method based on a multifocal X-ray source. By synchronously scanning a horizontally arranged multifocal X-ray source with a linear / area array detector, it achieves multi-view, high-efficiency whole-body tomographic data acquisition. Combined with advanced tomographic reconstruction algorithms, it solves the problem that existing X-ray imaging methods and equipment cannot simultaneously achieve full-body coverage, tomographic reconstruction accuracy, and scanning efficiency, thus meeting the clinical demand for rapid, accurate, and whole-body tomographic imaging. Specifically, the technical solution of this application is as follows:

[0005] In a first aspect, this application discloses a tomographic imaging device based on a multifocal X-ray source, comprising: a control system, a multifocal X-ray source, a detector, and an image processing system;

[0006] The control system is used to control the multifocal X-ray source to perform longitudinal scanning of the object being detected;

[0007] The multifocal X-ray source is provided with N X-ray tubes distributed laterally, each of which includes an independent cathode and anode for triggering the generation of multi-view X-rays;

[0008] The detector is used to receive X-rays passing through the object being detected and convert them into multi-view projection data;

[0009] The image processing system is connected to the detector and is used to process the multi-view projection data based on a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

[0010] In some embodiments, the tomographic imaging device based on a multifocal X-ray source further includes a longitudinal guide rail and a transverse support structure.

[0011] The lateral support structure includes a crossbeam made of alloy material, which is mounted on the longitudinal guide rails on both sides of the device; the lateral support structure is used to support the multifocal X-ray source and the detector.

[0012] In some implementations, the control system includes a main control module, a triggering module, and a motion control module.

[0013] The main control module is used to adjust the operating parameters of the multifocal X-ray source and the detector, and is also used to set the start and end points of the longitudinal scan.

[0014] The triggering module is used to receive instructions from the main control module to provide high voltage and low voltage to the X-ray tube in order to generate the X-rays;

[0015] The motion control module is used to control the multifocal X-ray source and the detector to move linearly along the longitudinal guide rail.

[0016] In some embodiments, the motion control module includes a servo motor and an encoder;

[0017] The motion control module drives the servo motor to enable the multifocal X-ray source and the detector to perform constant motion or segmented speed-changing motion along the longitudinal guide rail.

[0018] In some embodiments, the image processing system includes:

[0019] The preprocessing module is used to sequentially perform dark field correction, bright field correction, bad pixel calibration, geometric correction and noise reduction preprocessing on the multi-view projection data;

[0020] The tomographic reconstruction module is used to perform weighted filtering on the preprocessed multi-view projection data, and then use back projection technology to uniformly back-project the projection data from different angles onto the image matrix. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored. It is also used to solve the problem step by step using an iterative algorithm based on an algebraic model, calculate the projection error in each iteration, and further optimize the three-dimensional structure to obtain the three-dimensional reconstruction model.

[0021] In some embodiments, N ray tubes are distributed equidistantly or at equal angles relative to the center of the detector on the multifocal X-ray source, and the number of ray tubes is greater than 10.

[0022] In some embodiments, the detector is a linear array detector;

[0023] Alternatively, the detector may be an area array detector.

[0024] In some implementations, the lateral direction is horizontal, and the longitudinal direction is perpendicular to the lateral direction.

[0025] Secondly, this application also discloses a tomographic imaging method based on a multifocal X-ray source, the method being applicable to a tomographic imaging apparatus based on a multifocal X-ray source as described in any of the above embodiments, comprising:

[0026] Control the multifocal X-ray source to trigger the generation of multi-view X-rays and perform longitudinal scanning of the object being inspected;

[0027] Receive X-rays passing through the object being detected and convert them into multi-view projection data;

[0028] The multi-view projection data is processed using a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

[0029] In some embodiments, the multi-view projection data is processed based on a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object; specifically, this includes:

[0030] The multi-view projection data is sequentially subjected to dark field correction, bright field correction, bad pixel calibration, geometric correction, and noise reduction preprocessing.

[0031] The preprocessed multi-view projection data is weighted and filtered, and then back projection technology is used to uniformly back project the projection data from different angles onto the image matrix. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored.

[0032] The three-dimensional structure is solved step by step using an iterative algorithm based on an algebraic model. The projection error is calculated in each iteration, and the three-dimensional structure is further optimized to obtain the three-dimensional reconstruction model.

[0033] Compared with the prior art, this application has at least one of the following beneficial effects:

[0034] 1. This application's multi-view tomographic imaging significantly improves tomographic reconstruction accuracy and reduces artifact generation by utilizing multi-angle projection data provided by a multi-focal X-ray source. By replacing a single high-power CT tube with multiple small X-ray tubes, it avoids the need to move the focal point for imaging required by traditional single-focal X-ray sources, greatly increasing imaging speed, reducing motion artifacts, and achieving tomographic imaging functionality within the time required for traditional two-dimensional imaging.

[0035] 2. This application features high-speed continuous scanning: the horizontal lateral arrangement and synchronous motion scheme enable continuous seamless scanning of the head and feet of the object being detected, significantly shortening the scanning time; the rapid whole-body scanning capability reduces patient waiting and repositioning time, improves departmental turnover rate, and increases economic benefits.

[0036] 3. This application employs filtered back-projection technology and iterative reconstruction algorithms for tomographic reconstruction of images. This significantly improves the resolution of low-contrast structures. It also supports CPU parallel computing, increasing reconstruction speed while maintaining image resolution and contrast. Attached Figure Description

[0037] The preferred embodiments will now be described in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of this application.

[0038] Figure 1 This is a schematic diagram of the structure of an embodiment of a tomographic imaging device based on a multifocal X-ray source according to this application;

[0039] Figure 2 This is a schematic diagram of another embodiment of a tomographic imaging device based on a multifocal X-ray source according to this application;

[0040] Figure 3 This is a schematic diagram of another embodiment of a tomographic imaging device based on a multifocal X-ray source according to this application;

[0041] Figure 4 This is a flowchart illustrating the steps of an embodiment of a tomographic imaging method based on a multifocal X-ray source according to this application;

[0042] Figure 5 This is a flowchart illustrating the steps of another embodiment of a tomographic imaging method based on a multifocal X-ray source according to this application.

[0043] Icon labels:

[0044] 10 - Multifocal X-ray source; 20 - Detector; 30 - Object being detected; 40 - Control system; 50 - Image processing system; 60 - Lateral support structure; 70 - Longitudinal guide rail. Detailed Implementation

[0045] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0046] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or sets.

[0047] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0048] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0049] Current mainstream systems typically employ a combination of a single-focus X-ray source and a flat-panel or linear array detector. This allows for the acquisition of a two-dimensional projection image through a single exposure, followed by reconstruction algorithms to achieve tomographic imaging. While this approach is mature and cost-effective, it has revealed several shortcomings in practical applications.

[0050] First, the physical characteristics of a single-focus X-ray source fundamentally limit the imaging efficiency of the system. Because the source can only emit X-rays from a single spatial location, each exposure acquires projection data from only one viewpoint. To complete a full tomographic scan, the X-ray source-detector system must be mechanically rotated multiple times around the object being scanned. This sequential operation significantly extends scan time; for example, a whole-body scan using traditional rotating CT and other tomographic equipment typically takes several minutes, requiring the patient to lie flat and the gantry to rotate around the scan, limiting the scan volume and making it unsuitable for standing whole-body tomography. For standing patients requiring whole-body imaging, the patient must maintain a fixed posture for an extended period, increasing the risk of motion artifacts and reducing the pass rate of clinical examinations.

[0051] In dynamic imaging scenarios, monofocal X-ray systems struggle to capture rapidly changing physiological processes. While monofocal X-ray systems can image multiple parts of a standing patient, they only provide planar projection images and cannot achieve volumetric tomographic reconstruction.

[0052] Secondly, single-focus X-ray source equipment can only acquire projection data from a single viewpoint, and the sparsity of this projection data severely limits the quality of the reconstructed image. Multi-view tomography is impossible, resulting in low reconstruction accuracy. Furthermore, this single-view projection data leads to severe fringe artifacts and loss of detail in the reconstruction algorithm, especially noticeable in high-contrast structures (such as the junction of bone and soft tissue).

[0053] Long scanning times increase patient discomfort, reconstructed image artifacts may affect diagnostic accuracy, and insufficient system flexibility limits the expansion of application scenarios. Especially in scenarios such as emergency examinations, intraoperative imaging, and observation of musculoskeletal organs, the performance of existing systems often falls short of clinical needs. With the development of precision medicine and personalized diagnosis and treatment, the demand for rapid, high-resolution three-dimensional imaging is increasing, making technological innovation of monofocal X-ray imaging systems imperative. Therefore, this application proposes a novel multifocal X-ray imaging scheme to improve the perspective diversity and acquisition efficiency of projection data, thereby enhancing tomographic reconstruction accuracy, and is suitable for whole-body tomographic scanning of standing patients.

[0054] Reference manual attached Figure 1 As shown, one embodiment of a tomographic imaging device based on a multifocal X-ray source according to this application specifically includes:

[0055] Multifocal X-ray source 10, detector 20, control system 40 and image processing system 50.

[0056] The control system 40 is used to control the multifocal X-ray source 10 to perform longitudinal scanning of the object 30 being inspected. Specifically, the control system is used to adjust and control the operating parameters of the X-ray device, such as tube voltage, tube current, and exposure time. It typically includes a control console, operating interface, and various electronic devices, capable of adjusting parameters according to different detection requirements to ensure imaging quality and safety.

[0057] The multifocal X-ray source 10 is provided with N X-ray tubes distributed laterally, each of which includes an independent cathode and anode for triggering the generation of multi-view X-rays.

[0058] In this embodiment, the horizontal direction is horizontal, that is, the direction parallel to the ground. The longitudinal direction is perpendicular to the horizontal direction, that is, the longitudinal direction refers to the direction perpendicular to the horizontal direction. Preferably, the longitudinal direction is perpendicular to the ground.

[0059] In one embodiment of this invention, N X-ray tubes are distributed equidistantly or at equal angles relative to the imaging center on the multifocal X-ray source, and the number of X-ray tubes is greater than 10. (See attached specification) Figure 2 As shown, N X-ray tubes include X-ray sources 1-1, 1-2, ..., 1-N. The N X-ray sources are arranged in a line. In other embodiments of this example, the N X-ray sources arranged in a line are equivalent to the detector centers being arranged at equal angles; the specific arrangement and spacing are not specifically limited in this application. The multifocal X-ray sources consist of N X-ray tubes arranged horizontally, each X-ray source having an independent cathode and anode at its focal point. Optionally, the N X-ray sources are emitted sequentially or simultaneously according to a beam emission strategy under the control of the control system 40. The object 30 being detected is scanned from different viewing angles.

[0060] The detector 20 is used to receive X-rays passing through the object being detected and convert them into multi-view projection data.

[0061] Specifically, the detector receives X-rays passing through the object being detected and converts them into electrical signals or image data. When N X-ray sources emit beams sequentially according to a beam-emission strategy under the control of the control system, multifocal X-ray sources can emit X-rays at different time sequences. The detector uses time-resolved technology to distinguish rays from different focal points. For example, the emission time of the X-ray sources is controlled by a pulse generator, and the arrival time of each pulse is recorded using the detector's high-speed readout capability, thereby distinguishing rays from different focal points.

[0062] When N X-ray sources emit beams simultaneously according to a beam-emission strategy under the control of a control system, the focal positions of the multifocal X-ray sources are different, and the incident angles of the rays arriving at the detector will also be different. The detector distinguishes between rays with different incident angles, thereby achieving the differentiation of different focal points.

[0063] The image processing system 50 is connected to the detector 20 and is used to process the multi-view projection data based on the tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

[0064] In this embodiment, the tomographic reconstruction algorithm uses mathematical methods to deduce the internal structure of the scanned object from X-ray projection data at different angles.

[0065] Specifically, the image processing system includes functions such as image acquisition, processing, and reconstruction. It digitizes the signals acquired by the detector, generating high-quality two-dimensional or three-dimensional images through operations such as noise reduction, contrast enhancement, and detail reconstruction. The final generated image model and three-dimensional volumetric data are displayed using volume rendering or maximum density projection (MIP). Simultaneously, it interacts with the PACS system via the DICOM network transmission protocol (C-STORE / SCU). The user interface provides parameter settings, reconstruction progress monitoring, dynamic adjustment of window width and level, as well as real-time preview and post-processing functions to meet the needs of efficient clinical operations. In specific implementations, the terminal devices described in this application embodiment include, but are not limited to, desktop computers and tablet computers with displays.

[0066] Based on the above embodiments, this application discloses another embodiment of a tomographic imaging device based on a multifocal X-ray source, wherein the detector is a linear array detector or an area array detector.

[0067] In one embodiment of this invention, the detector is a linear array detector. Specifically, the linear array detector is arranged linearly in one-dimensional direction. To acquire two-dimensional image information, scanning technology is required to scan the target object row by row or column by column. Multiple one-dimensional images are then stitched together to form a two-dimensional image. The linear array detector can quickly complete data acquisition and processing at high line frequencies, offering high cost-effectiveness and high sensitivity.

[0068] In another embodiment of this invention, the detector is an area array detector. An area array detector is distributed in a matrix within a two-dimensional space, capable of capturing a complete two-dimensional image at once. It is highly efficient in acquiring two-dimensional images, provides intuitive measurements, and is suitable for scenarios requiring rapid acquisition of large-area images. Area array detectors can provide high resolution and rich image details, are suitable for weak signal detection, and feature low dark noise and a high signal-to-noise ratio.

[0069] Optional and common detector types include flat panel detectors, gas detectors, fluorescent screen detectors, and photon counting detectors. These detectors mostly employ digital technology, featuring high resolution, fast response, and high sensitivity, providing clearer imaging results.

[0070] Based on the above embodiments, this application discloses another embodiment of a tomographic imaging device based on a multifocal X-ray source, the device further including a longitudinal guide rail and a transverse support structure.

[0071] The lateral support structure includes a crossbeam made of alloy material, mounted on the longitudinal guide rails on both sides of the device. The lateral support structure is used to support the multifocal X-ray source and the detector.

[0072] For details, please refer to the attached instruction manual. Figure 3 As shown. The lateral support structure 60 is a beam made of high-strength alloy material, mounted on vertical guide rails 70 on both sides. The lateral support structure 60 is used to support the multifocal X-ray source and detector assembly. The vertical guide rails 70 are used to provide the movement trajectory of the multifocal X-ray source 10 and detector 20. In this embodiment, the lateral direction is horizontal, that is, parallel to the ground. The longitudinal direction is perpendicular to the lateral direction, that is, the longitudinal direction refers to the direction perpendicular to the lateral direction. Preferably, the longitudinal direction is perpendicular to the ground.

[0073] In this application, the connection relationship between the vertical guide rail 70 and the transverse support structure 60 is not specifically defined. The term "installation" should be interpreted broadly, for example, it can refer to fixed installation, detachable installation, or integrated installation. The connection relationship can be direct connection or indirect installation through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0074] This application provides another embodiment of a tomographic imaging device based on a multifocal X-ray source. Based on any of the embodiments of the above methods, the control system includes a main control module, a trigger module, and a motion control module.

[0075] The main control module is used to adjust the operating parameters of the multifocal X-ray source and the detector, and also to set the start and end points of the longitudinal scan.

[0076] The triggering module is used to receive instructions from the main control module to provide high voltage and low voltage to the X-ray tube in order to generate the X-rays.

[0077] The motion control module is used to control the multifocal X-ray source and the detector to move linearly along the longitudinal guide rail.

[0078] Specifically, the main control module sets the longitudinal scanning speed and start and end points, ensuring the scanning path covers both ends of the object being inspected. The main control module also sets the operating parameters of the multifocal X-ray source to achieve precise imaging control. This includes multifocal control, X-ray energy and intensity control, and pulse exposure timing control. Simultaneously, the main control module coordinates the detector's operating parameters, such as acquisition frame rate, integration time, gain adjustment, and dynamic range optimization, ensuring a strict match between the detector's and X-ray source's emission periods to prevent signal loss or overexposure.

[0079] The trigger module receives instructions from the main control module and drives the X-ray tube through precise voltage regulation. Specifically, the trigger module generates X-rays by providing two different voltages: a high voltage is applied between the cathode and anode to create a strong electric field that accelerates electrons, causing them to strike the anode target with extremely high kinetic energy and generate X-rays through a characteristic X-ray emission mechanism. The low voltage is used to heat the cathode, causing it to release free electrons, providing an electron source for subsequent acceleration.

[0080] The multifocal X-ray source 10 and detector 20 move synchronously under the action of the motion control module to achieve precise scanning. The motion control module consists of a servo motor and an encoder, enabling synchronous, variable-speed movement of the X-ray source and detector along the vertical direction. Optionally, the motion control module adopts dual-axis linkage control, using a high-precision encoder to provide real-time position information and a PID algorithm to dynamically correct trajectory deviations, ensuring strict synchronization between the X-ray source focus switching and the detector's acquisition frame rate. During scanning, both must move collaboratively at a constant speed to avoid image distortion.

[0081] Preferably, the longitudinal direction is perpendicular to the ground, and the motion trajectory of the radiation source and the detector is a straight line motion from top to bottom or from bottom to top.

[0082] Based on the above embodiments, this application discloses another embodiment of a tomographic imaging device based on a multifocal X-ray source, wherein the motion control module includes a servo motor and an encoder.

[0083] Specifically, the motion control module drives the X-ray source and detector to translate along a preset guide rail using a high-precision motor (such as a stepper motor or servo motor), ensuring that the two maintain a strict geometric correspondence (such as a fixed distance or angle) throughout the scanning process. The motion trajectory and speed are programmed and set by the main control module, and the position error is monitored in real time through a closed-loop feedback system (such as an encoder or grating ruler), dynamically adjusting the motor output to eliminate deviations.

[0084] In one embodiment of this invention, the motion control module drives the servo motor to achieve constant motion between the multifocal X-ray source and the detector along the longitudinal guide rail.

[0085] Specifically, in constant speed mode, the system maintains a uniform speed to ensure uniform sampling, which is suitable for regular scanning.

[0086] In another embodiment of this invention, the motion control module drives the servo motor to enable the multifocal X-ray source and the detector to perform segmented speed-changing motion along the longitudinal guide rail.

[0087] Specifically, in the segmented speed-adjusting mode, the moving speed can be intelligently adjusted according to the structural characteristics of the object being detected (such as areas of abrupt changes in thickness). The speed is reduced in critical areas to increase sampling density, and accelerated in uniform areas to improve detection efficiency.

[0088] Optionally, the motion control module also integrates limit protection and vibration suppression functions to ensure smooth and reliable motion, ultimately achieving high-resolution, artifact-free imaging.

[0089] Based on the above embodiments, this application discloses another embodiment of a tomographic imaging device based on a multifocal X-ray source, wherein the image processing system includes:

[0090] The preprocessing module is used to sequentially perform dark field correction, bright field correction, bad pixel calibration, geometric correction, and noise reduction preprocessing on the multi-view projection data.

[0091] Specifically, after acquiring the detector's raw readings (raw projection data), a series of preprocessing operations are required on the multi-angle projection data acquired by the multifocal X-ray source. These preprocessing steps include, but are not limited to, brightness and darkness field correction, beam hardening correction, and noise reduction. For example, noise suppression is achieved using a noise model filter based on detector characteristics, and geometric correction of the projection data is performed based on an algorithm to compensate for multifocal position differences.

[0092] The tomographic reconstruction module is used to perform weighted filtering on the preprocessed multi-view projection data, and then use back-projection technology to uniformly project the projection data from different angles onto the image matrix. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored. It is also used to: solve the three-dimensional structure step by step using an iterative algorithm based on an algebraic model, calculate the projection error in each iteration, and further optimize the three-dimensional structure to obtain the three-dimensional reconstruction model.

[0093] Specifically, in one embodiment of this example, tomographic reconstruction is achieved using a filtered back projection (FBP) algorithm and an iterative reconstruction (ART / SIRT) method.

[0094] Filtered Back Projection (FBP) converts multi-view projection data into high-quality tomographic images. This algorithm employs weighted filtering (such as Ram-Lak, Shepp-Logan, or Hamming filters) to apply frequency domain correction to the projection data, suppressing high-frequency noise and enhancing edge information, while compensating for blurring effects during the backprojection process. In the backprojection stage, the algorithm dynamically adjusts the backprojection weights based on multifocal position information after back-integration filtering along the X-ray path, ensuring accurate fusion of data from different focal points. Finally, a high-contrast, low-artifact tomographic image is reconstructed through iterative optimization or analytical computation.

[0095] Iterative reconstruction algorithms (such as ART / SIRT) significantly improve image quality by progressively optimizing the mathematical relationship between projection data and the reconstructed image. ART (Algebraic Reconstruction Technique) employs a per-projection update strategy, using projection data from only a single viewpoint to correct the image estimate in each iteration, exhibiting fast convergence. SIRT (Simultaneous Iterative Reconstruction Technique), on the other hand, simultaneously integrates projection errors from all viewpoints for global optimization, resulting in greater computational complexity but better stability. SIRT establishes a linear equation model, combining regularization constraints (such as TV minimization to suppress noise) and prior knowledge to gradually reduce projection errors during iteration. Iterative reconstruction effectively overcomes problems such as projection sparsity and noise interference, and in scenarios involving finite-angle projection reconstruction, it can significantly improve image contrast (enhancing soft tissue resolution) and spatial resolution (preserving fine structures).

[0096] Preferably, GPU parallel computing technology can significantly improve the efficiency of X-ray image reconstruction. While iterative reconstruction and filtering back projection algorithms are being executed, the massively parallel architecture of the GPU is used to map filtering operations, back projection operations, and iterative reconstruction into parallel kernel functions, thereby enabling real-time processing of projection data.

[0097] In another embodiment of this invention, after completing the multi-view projection data preprocessing, a reconstruction algorithm is needed to calculate the tomographic image from the projection data. The basic principle of this algorithm can be expressed by the following formula.

[0098]

[0099] Where Y is the preprocessed projection data; I is the reconstructed tomographic image; and A is the system matrix representing the positional relationship between the X-ray source, detector, and image spatial coordinate system, which can usually be obtained through geometric correction. R(x) represents the data consistency constraint between x and y. The lower the value, the higher the data consistency. Common implementation methods include, but are not limited to, mean squared error and likelihood function. R(x) is the image regularization constraint, which is used to add artificially set additional constraints in the image domain. Common implementation methods include, but are not limited to, total variation (TV) regularization term. λ is an artificially set weight coefficient used to balance the data consistency constraint and the image regularization constraint.

[0100] The above formula can be solved using iterative algorithms, including but not limited to gradient descent, Algebraic Iterative Reconstruction (ART), Synchronous Iterative Image Reconstruction (SIRT), and Alternating Direction Multiplier Method (ADMM). These iterative algorithms should include steps such as orthographic projection and backprojection. Orthographic projection refers to the process of calculating the corresponding projection data from the image domain data; specific implementation methods include, but are not limited to, ray-driven and distance-driven methods. Backprojection refers to the process of accumulating the projection data into the image domain based on geometric correspondence; specific implementation methods include, but are not limited to, pixel-driven and distance-driven methods.

[0101] Based on the same concept, this application also discloses a tomographic imaging method based on a multifocal X-ray source. The method is implemented based on any of the aforementioned tomographic imaging devices based on a multifocal X-ray source. Specifically, an embodiment of the tomographic imaging method based on a multifocal X-ray source of this application is provided in the appendix to the specification. Figure 4 As shown, it specifically includes:

[0102] S100 controls the multifocal X-ray source to trigger the generation of multi-view X-rays to perform longitudinal scanning of the object being inspected.

[0103] S200, receives X-rays passing through the object being detected and converts them into multi-view projection data.

[0104] S300, the multi-view projection data is processed based on a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

[0105] Specifically, the multifocal X-ray source 10 is equipped with N X-ray tubes distributed laterally or at equal angles relative to the detector center. Each X-ray tube includes an independent cathode and anode for triggering the generation of multi-view X-rays. The N X-ray tubes include X-ray sources 1-1, 1-2, ..., 1-N. Under the control of the control system 40, the N X-ray sources emit beams sequentially or simultaneously according to a beam emission strategy. The object 30 under inspection is scanned from different perspectives. The detector 20 receives the X-rays passing through the object 30 under inspection and converts them into electrical signals or image data. The image processing system digitizes the signals acquired by the detector to generate high-quality two-dimensional or three-dimensional images.

[0106] Based on the above embodiments, this application discloses another embodiment of a tomographic imaging method based on a multifocal X-ray source. In step S300, the multi-view projection data is processed using a tomographic reconstruction algorithm to obtain the tomographic data of the detected object and a three-dimensional reconstruction model. (See attached specification.) Figure 5 As shown, it specifically includes:

[0107] S310, the multi-view projection data is sequentially subjected to dark field correction, bright field correction, bad pixel calibration, geometric correction and noise reduction preprocessing.

[0108] S320, the preprocessed multi-view projection data is weighted and filtered, and then the projection data from different angles is uniformly back-projected onto the image matrix using back projection technology. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored.

[0109] S330, based on an iterative algorithm of an algebraic model, solves the problem step by step, calculates the projection error in each iteration, and further optimizes the three-dimensional structure to obtain the three-dimensional reconstruction model.

[0110] Preferably, GPU parallel computing technology can significantly improve the efficiency of X-ray image reconstruction. While iterative reconstruction and filtering back projection algorithms are being executed, the massively parallel architecture of the GPU is used to map filtering operations, back projection operations, and iterative reconstruction into parallel kernel functions, thereby enabling real-time processing of projection data.

[0111] The tomographic imaging apparatus and method based on a multifocal X-ray source in this application have the same technical concept, and the technical details of the embodiments of the two are applicable to each other. To reduce repetition, they will not be repeated here.

[0112] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of program modules is merely an example. In practical applications, the above functions can be assigned to different program modules as needed, that is, the internal structure of the device can be divided into different program units or modules to complete all or part of the functions described above. The program modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software program unit. Furthermore, the specific names of the program modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0113] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

Claims

1. A tomographic imaging device based on a multifocal X-ray source, characterized in that, include: Control system, multifocal X-ray source, detector and image processing system; The control system is used to control the multifocal X-ray source to perform longitudinal scanning of the object being detected; The multifocal X-ray source is provided with N X-ray tubes distributed laterally, each of which includes an independent cathode and anode for triggering the generation of multi-view X-rays; The detector is used to receive X-rays passing through the object being detected and convert them into multi-view projection data; The image processing system is connected to the detector and is used to process the multi-view projection data based on a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

2. The tomographic imaging device based on a multifocal X-ray source as described in claim 1, characterized in that, It also includes longitudinal guide rails and transverse support structures; The lateral support structure includes a crossbeam made of alloy material, which is mounted on the longitudinal guide rails on both sides of the device; the lateral support structure is used to support the multifocal X-ray source and the detector.

3. The tomographic imaging device based on a multifocal X-ray source as described in claim 2, characterized in that, The control system includes a main control module, a trigger module, and a motion control module. The main control module is used to adjust the operating parameters of the multifocal X-ray source and the detector, and is also used to set the start and end points of the longitudinal scan. The triggering module is used to receive instructions from the main control module to provide high voltage and low voltage to the X-ray tube in order to generate the X-rays; The motion control module is used to control the multifocal X-ray source and the detector to move linearly along the longitudinal guide rail.

4. The tomographic imaging device based on a multifocal X-ray source as described in claim 3, characterized in that: The motion control module includes a servo motor and an encoder; The motion control module drives the servo motor to enable the multifocal X-ray source and the detector to perform constant motion or segmented speed-changing motion along the longitudinal guide rail.

5. A tomographic imaging device based on a multifocal X-ray source as described in claim 1, characterized in that, The image processing system includes: The preprocessing module is used to sequentially perform dark field correction, bright field correction, bad pixel calibration, geometric correction and noise reduction preprocessing on the multi-view projection data; The tomographic reconstruction module is used to perform weighted filtering on the preprocessed multi-view projection data, and then use back projection technology to uniformly back-project the projection data from different angles onto the image matrix. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored. It is also used to: solve the three-dimensional structure step by step using an iterative algorithm based on an algebraic model, calculate the projection error in each iteration, and further optimize the three-dimensional structure to obtain the three-dimensional reconstruction model.

6. The tomographic imaging device based on a multifocal X-ray source as described in claim 1, characterized in that: N X-ray tubes are distributed at equal intervals or at equal angles relative to the imaging center on the multifocal X-ray source, and the number of X-ray tubes is greater than 10.

7. A tomographic imaging device based on a multifocal X-ray source as described in claim 1, characterized in that: The detector is a linear array detector; Alternatively, the detector may be an area array detector.

8. A tomographic imaging device based on a multifocal X-ray source as described in any one of claims 1-7, characterized in that: The horizontal direction is horizontal, and the vertical direction is perpendicular to the horizontal direction.

9. A tomographic imaging method based on a multifocal X-ray source, characterized in that, The method is applicable to a tomographic imaging device based on a multifocal X-ray source as described in any one of claims 1-8, comprising: Control the multifocal X-ray source to trigger the generation of multi-view X-rays and perform longitudinal scanning of the object being inspected; Receive X-rays passing through the object being detected and convert them into multi-view projection data; The multi-view projection data is processed using a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object.

10. The tomographic imaging method based on a multifocal X-ray source as described in claim 9, characterized in that: The process of processing the multi-view projection data using a tomographic reconstruction algorithm to obtain the tomographic data and three-dimensional reconstruction model of the detected object specifically includes: The multi-view projection data is sequentially subjected to dark field correction, bright field correction, bad pixel calibration, geometric correction, and noise reduction preprocessing. The preprocessed multi-view projection data is weighted and filtered, and then back projection technology is used to uniformly back project the projection data from different angles onto the image matrix. By superimposing the projection information from all directions, the three-dimensional structure of the detected object is restored. An iterative algorithm based on an algebraic model is used to solve the problem step by step. The projection error is calculated in each iteration, and the three-dimensional structure is further optimized to obtain the three-dimensional reconstruction model.

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