Fast 3D radiography with multiple pulsed X-ray sources by using electromagnetic field to deflect the tube electron beam

Abstract

The present invention proposes an X-ray imaging system that uses multiple pulsed X-ray sources to perform efficient and ultrafast 3D radiography. There are multiple pulsed X-ray sources mounted on a moving structure to form a source array. The multiple X-ray sources move simultaneously relative to an object at a constant speed as a group on a predefined arc track. The electron beam in each individual X-ray tube is deflected by a magnetic field or an electric field to move the focus a small distance. When the focus of the X-ray tube beam has a speed equal to the group speed but has an opposite direction of movement, the X-ray source and the X-ray flat panel detector are activated by an external exposure control unit so that the source tubes are equally and temporarily kept stationary. 3D scanning can cover a much wider sweep angle in a much shorter time, and image analysis can also be performed in real time.

Description

[0001] This application claims the priority of the following applications: Provisional Application Serial No. 63182426 filed on April 30, 2021; Provisional Application Serial No. 63226508 filed on July 28, 2021; Provisional Application Serial No. 63170288 filed on April 2, 2021, Provisional Application Serial No. 63175952 filed on April 16, 2021, Provisional Application Serial No. 63194071 filed on May 27, 2021; Provisional Application Serial No. 63188919 filed on May 14, 2021; Provisional Application Serial No. 63225194 filed on July 23, 2021; Provisional Application Serial No. 63226508 filed on July 28, 2021; Provisional Application Serial No. 63170288 filed on April 2, 2021, Provisional Application Serial No. 63175952 filed on April 16, 2021, Provisional Application Serial No. 63194071 filed on May 27, 2021 Provisional application serial number 63209498 filed on June 11; provisional application serial number 63214913 filed on June 25, 2021; provisional application serial number 63220924 filed on July 12, 2021; provisional application serial number 63222847 filed on July 16, 2021; provisional application serial number 63224521 filed on July 22, 2021; and U.S. application serial number 17149133 filed on January 24, 2021, which U.S. application subsequently claims priority to provisional serial number 62967325 filed on January 29, 2020, and the contents of the above applications are incorporated by reference. Technical Field

[0002] This patent specification is in the field of 3D X-ray radiography systems and methods and in particular relates to the use of pulsed X-ray sources and X-ray digital flat panel detectors. Background Art

[0003] Digital tomosynthesis (DTS) performs high-resolution limited-angle tomography at radiation dose levels comparable to conventional radiography.

[0004] When tomosynthesis is performed, the X-ray source will need to be moved in an arc around the object being scanned. As the X-ray source moves around the object, a series of X-ray images are acquired at different angles.

[0005] The collected data set allows the reconstruction of parallel planes. Each plane is clearly visible, and those out-of-plane tissue images are blurry. Generally, a wider sweep angle will generate more data projections and lead to better 3D resolution, but it takes longer. In addition, data processing is manufacturer-specific because different reconstruction algorithms may be used.

[0006] These kinds of digital tomosynthesis systems and methods can be applied to X-ray 3D radiography applications such as X-ray mammography, X-ray 3D chest diagnostic systems for COVID, X-ray 3D non-destructive testing (NDT) systems, and X-ray 3D security inspection systems.

[0007] There is prior art that utilizes a single X-ray source and a single flat panel to perform X-ray 3D radiography. However, there are disadvantages in the prior art.

[0008] The main disadvantage is that a single X-ray source takes a long time to acquire a good data projection. This is true for both continuous mode, where the source emits X-rays as it moves, and stepper mode, where the source moves to a certain position, stops and emits X-rays, and continues to move to the next position.

[0009] Although all patients want X-ray imaging to be completed as quickly as possible, there is a minimum X-ray source travel sweep angle requirement. If the sweep angle is too small, the X-ray source can travel less distance and the total time required is less, and the system will have a smaller number of data projections. A smaller number of data projections will result in lower depth resolution and loss of detail perception. On the other hand, if the sweep angle needs to be large enough to achieve good data projection to obtain better 3D resolution, a single X-ray source may mechanically travel too long a distance, so that the patient will feel uncomfortable and can no longer keep the breast still. In some cases, a 50-degree sweep will take up to about half a minute.

[0010] The second disadvantage is that it is difficult to perform real-time reconstruction because the whole process is slow. Typically, existing technologies take tens of seconds to complete a sweep.

[0011] In the present invention, fast 3D radiography with multiple pulsed X-ray sources by deflecting the electron beam of the X-ray tube using electric or magnetic fields is proposed. It utilizes motion control, multiple pulsed X-ray sources and deflection electric or magnetic fields.

[0012] The mechanism of deflecting the electron beam by a magnetic field is similar to the use of a magnetic deflection yoke at a cathode ray tube. However, the present invention will deflect the electron beam horizontally in only one direction.

[0013] Another way to deflect the electron beam is to place a pair of electrodes inside or outside the X-ray tube after the electron gun structure. For high frequencies, electrostatic deflection is more common than a large inductor driving the deflection yoke.

[0014] Compared to electrostatic deflection, magnetic deflection has less obstruction at the X-ray tube, allowing for larger diameter electron beams. Summary of the invention

[0015] In a first aspect, a system for providing fast 3D radiography using multiple pulsed X-ray sources in motion, the system having: a primary motor table that moves freely on an arc-shaped guide rail with a predetermined shape; a primary motor that engages with the primary motor table and controls the speed of the primary motor table; multiple X-ray sources, each of which moves on the primary motor table; a supporting frame structure that provides a housing for the primary motor table; a flat panel detector for receiving X-ray imaging data; a deflection plate for generating an electric field or a magnetic coil yoke for generating a magnetic field at the electron beam of the X-ray tube.

[0016] In a second aspect, a method for fast 3D radiography using multiple pulsed X-ray sources in motion includes: positioning a primary motor table to a predetermined initial position; sweeping the primary motor table at a predetermined constant speed by the primary motor; deflecting the X-ray tube electron beam in a predetermined sequence by applying a voltage to a plate or by applying a current to a magnetic coil; electrically activating the X-ray source and the X-ray flat panel detector when the X-ray tube focus moves in a direction opposite to the direction of the primary motor table and at a selected speed of the primary motor table; and acquiring image data from the X-ray source using the flat panel.

[0017] On the other hand, an X-ray imaging system for performing ultrafast, efficient 3D radiography using multiple pulsed X-ray sources in motion is proposed. In the system, multiple pulsed X-ray sources are mounted on a moving structure to form a source array. The multiple X-ray sources move simultaneously around an object at a constant speed of the group on a predefined arc track. The X-ray tube focus at each X-ray source can also be quickly moved a small distance around its static position by deflecting an electric field or a deflecting magnetic field. When the X-ray tube focus on a separate X-ray source has a speed equal to the group speed but an opposite direction of movement, the separate X-ray source is triggered by an external exposure control unit. This arrangement allows the X-ray source to remain relatively stationary during the X-ray pulse trigger exposure duration. Multiple X-ray sources result in a greatly reduced source travel distance for a separate X-ray source. The X-ray receiver is an X-ray flat panel detector. 3D radiographic image projection data can be acquired in a much shorter period of time with an overall much wider sweep, and image analysis can also be performed in real time while scanning is being performed.

[0018] On the other hand, an X-ray imaging system that uses multiple pulsed X-ray sources in motion to perform efficient and ultrafast 3D radiography includes multiple pulsed X-ray sources mounted on a moving structure to form a source array. The multiple X-ray sources move simultaneously relative to the object at a constant speed as a group on a predefined arc track. The focus at each individual X-ray source can also move quickly around its static position at a small distance. When the X-ray tube focus of the individual X-ray source has a speed equal to the group speed but has an opposite moving direction, the individual X-ray source and the X-ray detector are activated by an external exposure control unit. This arrangement allows the X-ray source to remain relatively stationary during the activation of the X-ray source and the exposure of the X-ray detector. The X-ray receiver is an X-ray flat panel detector. Multiple X-ray sources in motion operation result in a greatly reduced source tube travel distance for individual X-ray sources. 3D radiographic image data can be acquired in a much shorter time with a much wider overall sweep angle, and image analysis can also be performed in real time while scanning.

[0019] In a specific implementation, a random firing scheme may also be used to randomly activate X-rays from one of the sources in the array. The results of each and cumulative analysis determine the next X-ray source and exposure conditions. 3D X-ray radiographic images are reconstructed based on each image with the angled geometry of the X-ray exposure source. Much wider applications include: 3D mammography or tomosynthesis, chest 3D radiography or fast 3D NDT for COVID, fast 3D X-ray security inspections.

[0020] Advantages of the above described system may include one or more of the following. Various embodiments of multiple X-ray sources in motion are used in a novel ultrafast 3D radiography system.

[0021] The first advantage is that the overall system speed is several times faster. Each X-ray source will only need to mechanically travel a small fraction of the total distance in the arc trajectory. This greatly reduces the amount of data acquisition time required for the patient at the X-ray diagnostic machine.

[0022] The second advantage is that image analysis can also be done in real time while the scan is in progress. The judgment of the captured image will affect the position of the X-ray source focus for the next shot. There is no need to wait until the entire image is acquired before performing layered image reconstruction.

[0023] The third advantage is that high resolution and high contrast images can be acquired due to the reduction of motion artifacts. Each X-ray source has its own electric or magnetic field that moves the X-ray source focus around its origin. The combination of the focus movement speed and the orbital speed results in the relative static position of the X-ray sources when the individual X-ray sources are activated.

[0024] The fourth advantage is that the system can make much wider sweeps to acquire more data projections at a faster speed. More data projections means better image construction, which will lead to reduced misdiagnosis rates.

[0025] The fifth advantage is that due to the wider angle and faster imaging acquisition, a time component can be added to the 3D spatial imaging to form a 4D imaging data set.

[0026] The present invention has been described in terms of the preferred embodiments, and it should be recognized that equivalents, alternatives and modifications, aside from those explicitly stated, are possible and within the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 An ultrafast 3D digital radiography system with multiple X-ray source tubes in motion using deflection electric fields is shown.

[0028] Figure 2 Part of an ultrafast 3D digital radiography system with a moving X-ray source tube using a deflection magnetic field is shown.

[0029] Figure 3 A five X-ray source system is shown which acquires 25 projection data sets with each X-ray source traveling only one fifth of the total distance.

[0030] Figure 4 An exemplary deflection of an electron beam in an X-ray tube caused by a pair of magnetic coils when current flows through the coils is shown.

[0031] Figure 5 An exemplary deflection of an electron beam in an X-ray tube caused by a voltage difference between a pair of electrodes is shown. DETAILED DESCRIPTION

[0032] The following discussion describes in detail one embodiment of the present invention (and several variations of the embodiment). However, this discussion should not be construed as limiting the present invention to those specific embodiments. Those skilled in the art will also recognize many other embodiments. In order to define the full scope of the present invention, the reader is referred to the appended claims.

[0033] Therefore, for example, it will be appreciated by those skilled in the art that diagrams, schematic diagrams, diagrams, etc. represent conceptual views or processes that embody the system and method of the present invention. The functions of the various elements shown in the figure can be provided by using dedicated hardware and hardware capable of executing the associated software. Similarly, any switch shown in the figure is only conceptual. Their functions can be performed by the operation of program logic, by dedicated logic, by the interaction of program control and dedicated logic, or even manually, and specific techniques can be selected by the entity that realizes the present invention. It is also understood by those skilled in the art that the exemplary hardware, software, process, method and operating system described herein are for illustrative purposes, and are therefore not intended to be limited to any particular specified manufacturer.

[0034] Figure 1 A novel ultrafast 3D digital imaging system with multiple pulsed X-ray sources using electric field deflection tube electron beams is shown. It includes: a primary motor 3 coupled to a primary motor stage 4; a plurality of X-ray tubes 6, each in an X-ray source tube housing 5; and a pair of deflection plates 7 on each side of each tube 6. The X-ray source tube housing 5 is mounted on a supporting frame structure 2, and all X-ray source tube housings move together on the primary motor stage 4.

[0035] By applying a voltage difference at the electric deflection plates 7, an electric field will be formed between the electric deflection plates 7, such as Figure 5 The strength of the electric field varies based on the applied voltage. Deflection of the electron beam of an X-ray tube can be achieved by using a deflection magnetic field, such as Figure 4 As shown. The primary motor 3 is mechanically coupled to the primary motor table 4 to control the speed of the primary motor table 4. The X-ray source moves along an arc at the same speed as the primary motor table 4, wherein the primary motor 3 is on one side of the primary motor table 4. The supporting frame structure 2 provides a housing for the primary motor table 4 and the X-ray source. The flat panel detector 1 receives X-ray imaging data. The paired deflection plates 7 or paired magnetic coil 8 yokes generate an electric field or a magnetic field at the electron beam 9 of the X-ray tube.

[0036] The multiple pulsed X-ray sources or X-ray tubes 6 are mounted on a primary motor table 4 to form a source array. The multiple X-ray sources move simultaneously relative to the object at a constant speed as a group on a predefined arc track. The electron beam 9 in each individual X-ray tube can be deflected by a magnetic field or an electric field to move the focus a small distance. When the focus of the X-ray tube beam has a speed equal to the group speed but has an opposite direction of movement, the X-ray tube 6 and the X-ray flat panel detector 1 are activated by an external exposure control unit so that the source tubes are equally and temporarily kept stationary. In the case where the multiple sources or X-ray tubes 6 work in parallel, the system only moves a portion of the distance that a single tube system must move. Therefore, 3D scanning can cover a much wider sweep angle in a much shorter time, and image analysis can also be performed in real time.

[0037] In order to provide power to the moving structure, the primary motor 3 is engaged with the primary motor table 4 through gears. The primary motor 3 can move the primary motor table 4 along the rigid guide at a predetermined constant speed. By applying a voltage to the pair of deflection plates 7 at the X-ray tube 6, the X-ray tube electrons can be deflected before they reach the X-ray tube target 11. By fine-tuning the voltage, the electron focus can be moved in the direction of the primary motion table 4. When the focus speed is equal to the primary motion table 4 and has an opposite direction, the X-ray tube 6 and the X-ray flat panel detector 1 are triggered. At this triggering moment, the X-ray tube 6 and the X-ray detector 1 actually have a relative static position.

[0038] The primary motion table 4 with an X-ray source moves on an arc-shaped guide rail with a predetermined shape, and the primary motor 3 moves the X-ray source on the primary motion table 4 at a constant speed. A plurality of X-ray sources are mounted on the primary motion table 4 in the form of a source array. The plurality of X-ray sources move simultaneously around an object at a constant speed as a group on a predefined track. The focus of the X-ray source can also move a small distance quickly around its static position. When the X-ray tube focus on a separate X-ray source has a speed equal to the group speed but an opposite moving direction, the corresponding X-ray source is triggered by an external exposure control unit. This arrangement allows the X-ray source to remain relatively stationary during the exposure duration of the X-ray pulse triggering. Multiple X-ray sources result in a greatly reduced source travel distance for a single X-ray source. A flat panel detector 1 is placed on a supporting frame structure to receive X-ray imaging data. Pairs of deflection plates 7 or magnetic coil 8 yokes are positioned to generate an electric field or magnetic coil at the X-ray tube electron beam 9.

[0039] The primary motor stage 4 will mechanically move the multiple X-ray tubes 6 in the array and the detectors in a predetermined arc track. The set of multiple X-ray tubes can be connected to the primary motor stage 4 via a rack and pinion mechanical structure, or fixed on multiple bases at a fixed distance between each other. The X-ray tube focus is deflected in one direction and the opposite direction by an electric or magnetic field. While moving on the arc track, the individual X-ray tubes will move rapidly around their static position by deflecting the electric or magnetic field. The X-ray source from one of the sources can be randomly activated by a control unit, wherein 3D radiographic image data acquisition and image analysis can be performed in real time while the scan is in progress. A preferred method for triggering multiple pulsed X-ray sources in motion includes: positioning the primary motor table 4 to a predetermined initial position; sweeping the primary motor table at a predetermined constant speed by the primary motor 3; deflecting the X-ray tube electron beam 9 in a predetermined sequence by applying a voltage to the plate or applying a current to the magnetic coil; electrically activating the X-ray source and the X-ray flat panel detector 1 when the X-ray tube focus moves in a direction opposite to the direction of the primary motor table 4 and at a selected speed of the primary motor table 4; and acquiring image data from the X-ray flat panel detector 1.

[0040] The X-ray source tube housing 5 is pivotally mounted on an axis parallel to the X-ray source mounting plate and coupled to a rotation drive mechanism that rotates the X-ray source tube housing around an axis parallel to the X-ray source mounting plate. In the present application, the angle of rotation is represented by an angle "β". The amount of the angle of rotation can be set by the user based on specific requirements. In an exemplary embodiment, the angle of rotation is about 12.5 degrees. A single rotation drive couples the X-ray source tube housing 5 to a geared motor for rotating the X-ray source tube housing 5. The rotation drive mechanism includes two pairs of pulleys, and each pair of pulleys is mounted at both ends of the X-ray source tube housing 5 and coupled by a drive gear. They drive the gears and rotate the X-ray source tube housing 5 when the rotation drive is activated by software. The preferred speed range of the X-ray tube housing 5 is about 20 mm / s to about 50 mm / s.

[0041] The pair of deflection plates 7 are set to the arc of the X-ray source and the X-ray flat panel detector 1. The deflection plates 7 are adjusted to the position where the X-ray source and the flat panel detector 1 are not in a straight line. When the arc shape is predefined and the X-ray source is mechanically moved in a circular motion around its focus according to the speed control unit (which controls the speed of the elementary motor 3) in combination with the X-ray exposure control unit (which controls the duration of the X-rays output from the X-ray source by the trigger signal generated from the trigger source), the X-ray source will draw a curve in 3D space on the detector. At the same time, the X-ray source will also draw a corresponding curve in 3D space with a certain degree of rotation on the detector. The image data can be reconstructed using the knowledge of the target object structure at each position through which the X-ray source moves. The knowledge of the target object geometry can be calculated using pre-measured landmarks and image processing tools to produce accurate geometric modeling of internal body structures in the patient. One embodiment includes a two-dimensional 3D camera or a set of 3D cameras to detect patient movement during the process in real time and compensate for patient movement.

[0042] The support frame structure 2 provides a housing for the X-ray source moving mechanism. The arc guide, which can be part of a single axis motion table, is arranged to move in one direction along a circular track. An electronic controller (not shown) allows the speed of the arc guide to be accurately controlled. A plurality of pulsed X-ray sources are mounted on the moving mechanism in an array around the periphery of the arc guide. For the X-ray source, any suitable type of X-ray tube can be used. The arc guide and its associated structure can move smoothly at high speed and minimal friction on the support frame structure 2. Each X-ray source is triggered when it becomes in position relative to the patient during the sweep. Each X-ray source must be positioned so that the focus of the X-ray source does not irradiate any part of the patient before the X-ray source is triggered.

[0043] In one embodiment, the system uses multiple pulsed X-ray sources in motion to perform ultrafast, efficient 3D radiography. In the system, multiple pulsed X-ray sources are mounted on a moving structure to form a source array. The multiple X-ray sources move simultaneously around an object at a constant speed of the group on a predefined arc track. The X-ray tube focus at each X-ray source can also be quickly moved a small distance around its static position by deflecting an electric field or a deflecting magnetic field. When the X-ray tube focus on a separate X-ray source has a speed equal to the group speed but an opposite moving direction, the corresponding X-ray source is triggered by an external exposure control unit. This arrangement allows the X-ray source to remain relatively stationary during the X-ray pulse trigger exposure duration. Multiple X-ray sources result in a greatly reduced source travel distance for a single X-ray source. The X-ray receiver is an X-ray flat panel detector 1. Therefore, 3D radiographic image projection data can be acquired in a much shorter time with an overall much wider sweep, and image analysis can also be performed in real time while scanning.

[0044] More details of the ultrafast 3D digital imaging system with multiple pulsed X-ray sources using a deflection magnetic field to deflect the tube electron beam 9 are given in Figure 2 , which shows one of the multiple X-ray sources, each of which includes a pair of magnetic deflection coils 8, which are placed at the X-ray tube 6 in the X-ray source tube housing 5. By applying current at the magnetic deflection coils 8, a magnetic field will be formed between the pair of magnetic deflection coils 8. The strength of the magnetic field varies based on the current flowing through the magnetic coils.

[0045] During operation, the elementary motor 3 engages the elementary table 4 through gears to provide movement of the X-ray source in the housing 5. The elementary motor 3 can move the elementary table 4 along the rigid rail at a predetermined constant speed. By applying current to the paired magnetic deflection coils 8 at the X-ray tube 6, the X-ray tube electron beam 9 can be deflected by the force from the magnetic field before the electrons reach the X-ray tube target. By fine-tuning the current, the electron focus can be moved in the direction of the elementary motor table 4. When the X-ray tube focus movement speed is equal to the speed of the primary motion table 4 and has the opposite direction, the X-ray tube 6 and the X-ray detector 1 are triggered. At this triggering moment, the X-ray tube 6 and the X-ray detector 1 actually have a relative static position.

[0046] The X-ray tube 6 is the heart of the X-ray machine. The X-ray tube 6 has a high voltage terminal connected to an external high voltage power supply through an electric wire. The X-ray tube 6 generates a current along an electron gun column in a vacuum container inside the X-ray tube 6.

[0047] Paired magnetic deflection coils 8 are used to adjust the beam of the X-ray tube 6. The X-ray tube 6 or source can be a point source, and a smaller focal spot size is ideal. A smaller focal spot size will have better image resolution. It is desirable to spectrally filter the X-ray tube to produce an X-ray beam in the required energy range. The tube mounting assembly provides electrical and mechanical connections between the X-ray tube 6 and the primary motor stage 4. The tube mounting assembly has secondary or tertiary or more metal to shield against electrical interference. The front cover and rear cover can provide shielding against ambient radiation and airborne particles, respectively.

[0048] An X-ray source tube housing 5 in which an X-ray tube 6 is installed is movable on a primary motor table 4. The X-ray source tube housing 5 is installed at the primary motor table 4, which moves freely at a predetermined constant speed on an arc-shaped guide rail; a primary motor 3, which controls the speed of the primary motor table 4; and a plurality of X-ray sources, (one of which) is accommodated in the X-ray source tube housing 5, which all move simultaneously at the same speed as the primary motor table 4. The X-ray flat panel detector 1 is used to receive X-rays and send imaging data. It is installed around the rotation center of the primary motor table 4 to receive an X-ray beam transmitted through a portion of the object under test placed at the rotation center. An array of five X-ray sources is installed on the X-ray source tube housing 5 at equal angles to each other; they move at a constant speed together with the primary motor table 4. A collimator positioned between the X-ray source tube housing 5 and the flat panel X-ray detector 1 along the axis of motion of the primary motor table 4 can limit the horizontal component of the X-ray beam passing through. The support frame structure 2 provides a housing for the elementary motor stage 4 and electric field deflection means such as a pair of deflection plates 7 .

[0049] The primary motor 3 provides driving motion to move the primary motor table 4 on a predetermined track. A plurality of X-ray sources are mounted on the primary motor table 4 for sequentially emitting X-rays. The X-ray sources are arranged in an array configuration, and each X-ray source moves on the primary motor table along the same path at a constant speed and at a speed as a group simultaneously with other X-ray sources. The flat panel detector 1 is usually mounted on a supporting frame structure 2 to receive X-rays and send imaging data. Pairs of electric deflection plates 7 or magnetic deflection coils 8 yokes are located in front of the X-ray tube target 11 to control the position of the X-ray source focus. Technical features of an X-ray imaging system that uses multiple pulsed X-ray sources in motion to perform ultrafast, efficient 3D radiography: The first technical feature is that the primary motor table 4 moves on a predetermined track. Each X-ray source moves on the predetermined track with the primary motor table 4, and the X-ray source moves on the primary motor table 4 along the same path at a constant speed and at a speed as a group simultaneously with other X-ray sources.

[0050] The elementary motor table 4 can move freely on an arc-shaped guide rail with a predetermined shape. The elementary motor 3 engaged with the elementary motor table 4 controls the speed of the elementary motor table 4. In some specific implementations, the X-ray source can be mounted on the elementary motor table 4 and move around the object simultaneously on a predefined track at a constant speed of the group. The X-ray tube focus at each X-ray source can also be quickly moved a small distance around its static position by deflecting the electric field or the deflecting magnetic field. When the X-ray tube focus on a separate X-ray source has a speed equal to the group speed but an opposite direction of movement, the corresponding X-ray source is triggered by an external exposure control unit. This arrangement allows the X-ray source to remain relatively stationary during the X-ray pulse triggering exposure duration. Multiple X-ray sources result in a greatly reduced source travel distance for a single X-ray source. The X-ray receiver is an X-ray flat panel detector 1. Therefore, 3D radiographic image projection data can be acquired in a much shorter time with an overall much wider sweep, and image analysis can also be performed in real time while scanning is being performed.

[0051] The primary motion table 4 is mounted on a fixed base structure of the frame and is positioned so that it can move freely on an arc-shaped guide rail with a predetermined shape. The primary motor 3 drives the primary motor table 4. The primary motor speed controller controls the speed of the primary motor table based on the required movement time during scanning and the input from the computer system (or programmed timing). A power supply is connected to the primary motor to provide power for the primary motor operation. The primary motor table 4 is a drive element controlled by the primary motor 3, which moves in a sweeping motion in this direction at a constant speed along the guide rail of the base structure. The center of the primary motor table 4 is a column that supports the X-ray tube and the high voltage generator.

[0052] An X-ray flat panel detector 1 for an X-ray imaging system for providing fast 3D radiography using multiple pulsed X-ray sources in motion, the system having: a primary motor table 4, which moves freely on an arc guide rail with a predetermined shape; a primary motor 3, which is engaged with the primary motor table 4 and controls the speed of the primary motor table 4; a plurality of X-ray sources, each of which moves on the primary motor table 4; a supporting frame structure 2, which provides a housing for the primary motor table 4; a flat panel detector 1, which is used to receive X-ray imaging data; a pair of deflection plates 7 for generating an electric field or a pair of magnetic coil 8 yokes for generating a magnetic field at the electron beam 9 of the X-ray tube. The method of fast 3D radiography using multiple pulsed X-ray sources in motion comprises: positioning the elementary motor stage 4 to a predetermined initial position; sweeping the elementary motor stage at a predetermined constant speed by said elementary motor 3; deflecting the X-ray tube electron beam 9 in a predetermined sequence by applying voltage to the plate or by applying current to the magnetic coil 8; electrically activating the X-ray source and the flat panel detector when the X-ray tube focus moves in a direction opposite to the direction of the elementary motor stage 4 and at a selected speed of the elementary motor stage 4; and acquiring image data from the flat panel detector. In one embodiment, an X-ray imaging system for performing ultrafast, efficient 3D radiography using multiple pulsed X-ray sources in motion is presented.

[0053] Figure 3 An exemplary complete X-ray exposure position is shown. In this example, there are five X-ray tubes 6 in the X-ray source tube housing 5, and the five X-ray tubes 6 at the X-ray source tube housing 5 perform a total of 25 X-ray exposures at different angular positions. Each of the five X-ray tubes 6 only needs to travel one-fifth of the total coverage angle. Therefore, with multiple X-ray tubes 6 working in parallel, a large amount of projection data can be acquired in a fraction of the time compared to the amount of time of a single X-ray source. The X-ray flat panel detector 1 acts as an X-ray receiver. Electronic signals always travel faster than mechanical motion, and the bottleneck of the limiting factor is always the motor table motion itself. The next bottleneck is the detector reading limit. Because the detector also takes some time to read out many megapixel data and then transfer it to the computer.

[0054] Given the widespread availability of ultra-high-speed computers, image analysis can be performed in real time with image acquisition. The judgment of the image taken will affect the position of the X-ray tube 6 for the next shot. There is no need to wait until the entire image acquisition is completed before image reconstruction. Figure 3A five-X-ray source system is shown, which acquires 25 projection data sets by traveling only one-fifth of the total distance. The X-ray tube 6 is a group of multiple pulsed X-ray sources to form a source array, or multiple groups of pulsed X-ray sources mounted on a moving structure to form a source array. The multiple X-ray sources move simultaneously relative to the object at a constant speed as a group on a predefined arc track. The focus at each X-ray source can also move quickly around its static position at a small distance. When the X-ray tube focus of the corresponding X-ray source has a speed equal to the group speed but an opposite moving direction, the X-ray source and the X-ray detector are activated by an external exposure control unit.

[0055] This arrangement allows the X-ray source to remain relatively stationary during the activation of the X-ray source and the exposure of the X-ray detector. The X-ray receiver is an X-ray flat panel detector. The first advantage is that the overall system speed is several times faster. Each X-ray source will only need to mechanically travel a small portion of the entire distance in the arc trajectory. This greatly reduces the amount of data acquisition time required for the patient at the X-ray diagnostic machine. The second advantage is that image analysis can also be completed in real time while the scan is in progress. The judgment of the captured image will affect the X-ray source focus position for the next shot.

[0056] The X-ray source tube housing 5 contains a primary X-ray tube 6 powered by a high voltage generator. In this patent, only one primary X-ray tube source is described, but it should be understood that more than one source can be used simultaneously to acquire different parts of the 3D image data set. The primary X-ray tube housing 5 is mounted on a movable structure (not shown) with a motor control system to enable movement in any direction on an arcuate guide that forms part of a circular arc track or spiral motion track around the patient. The high voltage generator outputs a high voltage current that flows through a cable leading to an input connector on the back of the primary X-ray tube. In addition, the X-ray source may have an independent voltage controller that can adjust the output voltage for both the high voltage primary X-ray tube and the focus movement voltage of the separate X-ray tube to control the focus position around a static position.

[0057] A plurality of X-ray tubes 6 are arranged in an array. In an exemplary embodiment, the X-ray tubes 6 are mounted on a structure that is moved relative to an object on an arc-shaped guide by a primary motor. The order of moving the X-ray tube structure at a constant speed and a small angle is predefined to generate an array of X-ray tubes that are moving simultaneously around the object. At each point in time, the direction of movement of the X-ray tubes, the distance between adjacent X-ray tubes, and the time delay between adjacent X-ray tubes can be determined to form an arc-shaped trajectory for all X-ray tubes. At a certain timing point, the focus (electron beam) of each X-ray tube is moved around its static position by a predetermined electric field or magnetic field from a deflection plate. A high voltage power supply can generate a deflection electric field at a pair of deflection plates, which deflects the focus of the X-ray tube from its static position to a new position forming a predetermined geometric shape at a predetermined distance, such as Figure 5 shown.

[0058] The X-ray flat panel detector 1 is used as a detector for an X-ray imaging system. The X-ray flat panel detector 1 includes a plurality of individual detector panels, which are arranged in two dimensions to form a square or rectangular shape and can be sensitive to X-rays. The X-ray flat panel detector 1 is an ultra-high-speed, high-efficiency active pixel sensor flat panel detector 1 with fast readout capability. The X-ray flat panel detector 1 can provide images at a frame rate higher than 25fps. The X-ray flat panel detector 1 includes each detector panel, which can be individually addressed by an addressing unit through a panel driver for readout. The X-ray tube 6 is located inside the X-ray machine, where the X-ray tube focus is moved by a deflection electric field or a deflection magnetic field from an X-ray controller. The X-ray controller bypasses a trigger signal to the X-ray power supply to trigger the activation of the X-ray tube 6.

[0059] The paired magnetic deflection coils 8 are positioned at Figure 4 The X-ray source has a focal spot which can be moved by magnetic fields and generated by coils, respectively.

[0060] Figure 4An exemplary deflection of an electron beam in an X-ray tube that can be deflected by a magnetic coil 8 when current flows through the coil is shown. The X-ray tube 6 can be fixed on a support frame or have an electric actuation mechanism to achieve X-ray focus positioning. In the latter case, the X-ray tube can be moved together with a primary motor stage 4, which is engaged with a primary motor to rotate the rotor shaft to control the speed of the primary motor stage 4. On the other hand, the deflection plates are mounted to a platform at an equal distance from the X-ray source. The plates are part of a voltage / current drive system that can generate an electric field or a magnetic field. The plates are driven by a control board that receives commands from an exposure control unit via a digital interface. The voltage from the exposure control unit passes through a converter to energize the electric coil of the magnetic coil, which generates a magnetic field surrounding the X-ray tube. The exposure control unit controls the magnetic coil through a magnetic coil driver. After starting the scanning sequence, the control board triggers the individual pulsed X-ray sources using digital signals generated by the exposure control unit through signal cables. Upon receiving the trigger command, the corresponding pulsed X-ray source starts a ramp-up operation to increase the power output.

[0061] In an embodiment, the X-ray source in the X-ray tube is stationary at the start of operation, but when the X-ray receiver (flat panel detector) is to be exposed, the X-ray source moves in the direction opposite to the primary motor table 4 while being started at a selected speed. In another embodiment, the X-ray source can be randomly turned on by triggering from outside the system or from inside the system using a random firing scheme. The results of each and cumulative analysis determine the next X-ray source and exposure conditions. 3D X-ray radiographic images are reconstructed based on each image with an angled geometry of the X-ray exposure source. Much wider applications include: 3D mammography or tomosynthesis, chest 3D radiography or rapid 3D NDT for COVID, rapid 3D X-ray security inspections.

[0062] The X-ray tube electron beam 9 and the flat panel detector 1 are positioned in an arrangement parallel to each other. Due to the magnetic field generated by the magnetic coil yoke or the electric field generated by the deflector plate, the X-ray tube focus moves a small distance around a static position on the X-ray tube anode according to its design. In each instance of movement of the X-ray tube focus around its origin, the X-ray beam projected onto the region of interest is determined by the X-ray tube current intensity, which changes rapidly due to switching within a certain duration. The X-ray imaging system also includes a control unit with a random firing switching module (FFW) and an exposure control unit (ECU) for operating the X-ray source. The random firing switching module is connected to all X-ray sources. It uses an externally generated trigger signal to randomly fire one of the X-ray sources at a time. Therefore, the activation of each X-ray source occurs simultaneously with the image acquisition. When one of the X-ray sources is activated, the associated electronic unit (total unit) connected to the flat panel detector will control the electronic trigger signal applied to the flat panel detector so that the acquisition of X-ray imaging data starts simultaneously with the activation of the X-ray source.

[0063] Figure 5 The deflection of the electron beam in an exemplary X-ray tube caused by a voltage difference between the plates is shown. The X-ray tube 6 has a focal spot with a finite size at an initial position, which changes after the electric field or magnetic field has deflected the X-ray tube focal spot to a subsequent position. The multiple X-ray sources move on a predetermined track at the same speed as the elementary motor table but in the opposite direction to the elementary motor table. They are also positioned at selected angles relative to each other with respect to the first X-ray source and the second X-ray source. In this example, four pulsed X-ray sources move simultaneously relative to the object at a constant speed as a group, and move sequentially from one to another as they sweep across the object. The corresponding detectors are mounted on the opposite side of the elementary motor table 4 parallel to the movement direction of the pulsed X-ray sources.

[0064] The electric deflection plates 7 are located between the X-ray tube cathode and the target. Voltage pulses are applied to the electric deflection plates 7 to control the movement of the focus relative to the X-ray source along the tracking axis, as shown in the schematic diagram. Other voltage pulses are applied to the electric deflection plates 7 to control the movement of the focus in a direction perpendicular to the track axis, which results in the focus moving back and forth along the track axis in synchronization with other movements on the track axis. Magnetic coils are installed between the X-ray tube cathode and the target and are also used to control the movement of the focus. The X-ray tube electron beam 9 is deflected in the direction of movement of the primary motor stage 4 by applying different electric or magnetic field combinations to the deflection device at the same time.

[0065] The X-ray tube electron beam 9 moves its focus around the X-ray tube static axis through an external deflection electric field (plate) or an external deflection magnetic field (coil). When the elementary motor stage 4 is swept in a circular path at a predetermined sweep speed, the focus is continuously moved to scan the object. This method is accomplished in parallel using multiple X-ray sources.

[0066] The X-ray tube cathode 10 generates an electron beam 9, and after the electron beam 9 hits the X-ray tube target 11, X-rays are emitted, and the X-rays moving toward the object are called primary X-rays. A deflection coil may be located between the X-ray tube cathodes 10 to deflect the electron beam 9 toward the tube target 11 by passing current through the deflection coil. A high voltage generator (a structure that provides high voltage pulses) connected to the cathode generates an electrical pulse and sends it to the deflection coil to deflect the electron beam 9 before it hits the target.

[0067] The X-ray tube 6 may include an electron gun, a heated cathode 10, an X-ray tube target 11, or other material that generates an electron beam 9 from one end. The X-ray tube target 11 is mounted on the other end of the X-ray tube 6. Electrical insulators and materials are attached to the housing and are electrically conductive to the target. The electrical insulators may be made of many different materials. Examples of electrical insulators may include Teflon and / or other dielectric materials such as glass or mica. The housing may be made of many different materials. Examples of housings may include stainless steel, aluminum, plastic, ceramic, combinations thereof, or any other material that does not interfere with the transmission of X-rays. The electrical insulators and materials may have the same or different compositions and may be configured in a single or multiple layers between the target and the housing.

[0068] The primary motor table 4 is mounted on a supporting frame structure 2 that provides a housing for the primary motor table 4. An X-ray flat panel detector 1 for receiving X-ray flux is positioned to generate X-ray image projection data from the multiple X-ray sources. The X-ray sources are arranged on the primary motor table 4, which moves freely on an arc-shaped guide rail with a predetermined shape. The exposure control unit controls the electric field applied to each X-ray source to deflect the X-ray tube electron beam 9. The X-ray sources move simultaneously relative to the object at a constant speed as a group on a predefined track. Each X-ray source focus can also be moved quickly around its static position at a small distance by deflecting the electric field or the deflection magnetic field. When the X-ray tube focus on a separate X-ray source has a speed equal to the group speed but an opposite direction of movement, the corresponding X-ray source is triggered by an external exposure control unit. Multiple pulsed X-ray sources result in a greatly reduced source travel distance for a separate X-ray source.

[0069] The elementary motor table 4 is positioned at a predefined initial position and is swept on an arc track at a constant speed by the elementary motor. One or more X-ray sources are each moved on the elementary motor table 4. The predefined initial position can be set to any of various initial positions depending on how one wishes to position the object on the X-ray imaging machine for X-ray scanning. Various exemplary positions are chest X-ray scan (ventral / dorsal), chest CT scan, etc.

[0070] Various modifications and alterations of the present invention will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims. It should be noted that the steps recited in any method claim below do not necessarily need to be performed in the order in which they are recited. One of ordinary skill in the art will recognize variations in performing the steps based on the order in which the steps are recited. In addition, the lack of mention or discussion of a feature, step, or component provides a basis for a claim in which an absent feature or component is excluded by proviso or similar claim language.

[0071] Although various embodiments of the present invention have been described above, it should be understood that they are presented as examples rather than limitations. Various figures may depict exemplary architectures or other configurations for the present invention, in order to understand the features and functionality that may be included in the present invention. The present invention is not limited to the exemplary architectures or configurations illustrated, but various alternative architectures and configurations may be used to implement the desired features. In fact, it is obvious to those skilled in the art how alternative functions, logical or physical partitions and configurations may be implemented to implement the desired features of the present invention. In addition, many different component module names other than those described herein may be applied to each partition. In addition, for flow charts, operational descriptions, and method claims, the order in which the steps are presented herein should not force implementation of various embodiments to perform the described functionality in the same order, unless the context indicates otherwise.

[0072] Although the present invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects, and functions described in one or more of the individual embodiments are not limited to their applicability to the specific embodiment with which they are described, but rather may be applied alone or in various combinations to one or more of the other embodiments of the present invention, whether or not such embodiments are described and whether or not such features are present as part of the described embodiments. Therefore, the breadth and scope of the present valve should not be limited by any of the above-described exemplary embodiments.

[0073] Unless otherwise expressly stated, the terms and phrases used in this document and their variations should be interpreted as open-ended rather than restrictive. As an example of the foregoing, the term "including" should be interpreted as meaning "including but not limited to" or the like; the term "example" is used to provide an illustrative example of the items under discussion, rather than an exhaustive or restrictive list thereof; the term "a" or "an" should be interpreted as meaning "at least one", "one or more" or the like; and adjectives such as "conventional", "traditional", "normal", "standard", "known" and terms of similar meaning should not be interpreted as limiting the items described to a given period or to items available as of a given time. Instead, they should be interpreted as covering conventional, traditional, normal or standard technologies that are available or known now or at any time in the future. Therefore, where this document refers to technologies that are obvious or known to a person of ordinary skill in the art, such technologies cover those technologies that are obvious or known to a person of ordinary skill in the art now or at any time in the future.

[0074] The grouping of items connected with the conjunction "and / and" should not be understood as requiring each of these items to appear in the grouping, but should be understood as "and / or", unless otherwise expressly stated. Similarly, the grouping of items connected with the conjunction "or / or" should not be understood as requiring mutual exclusivity between the groupings, but should instead be understood as "and / or", unless otherwise expressly stated. In addition, although the items, elements or components of the present invention may be described or claimed in the singular, it is contemplated that the plural is within its scope unless limitation to the singular is expressly stated.

[0075] In some cases, the presence of broad words and phrases (such as "one or more", "at least", "but not limited to", or other such phrases) should not be understood to mean that narrower cases are intended or required to be used where such broad phrases may not be present. Use of the term "module" does not imply that the components or functionality described or claimed as part of a module are all configured in a common package. In fact, any or all of the various components of a module, whether control logic or other components, may be combined in a single package or maintained separately, and may further be distributed across multiple locations.

[0076] In addition, the various embodiments set forth herein are described with exemplary block diagrams, flow charts, and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives may be implemented without limitation to the illustrated examples. For example, the block diagrams and their accompanying descriptions should not be construed as mandating a particular architecture or configuration.

[0077] The foregoing description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but should be given the most comprehensive scope consistent with the principles and novel features disclosed herein.

[0078] Although several alternative embodiments of the present invention have been shown, it should be understood that certain changes may be made as will be known to those skilled in the art without departing from the basic scope of the present invention as discussed and listed above and below. In addition, the above-described embodiments are intended only to illustrate the principles of the present invention. They are not intended to limit the scope of the present invention to the disclosed elements.

Claims

1. A fast 3D radiography system with multiple pulsed X-ray sources using electromagnetic field deflection tube electron beams, the system comprising: A primary motor table, the primary motor table freely moving on an arc-shaped guide rail with a predetermined shape; an elementary motor engaged with the elementary motor stage and controlling the speed of the elementary motor stage; a plurality of X-ray sources, each X-ray source having a fixed anode and mounted at the elementary motor stage, each X-ray source including an X-ray tube focus; a supporting frame structure providing a housing for the primary motor table; An X-ray flat panel detector, the X-ray flat panel detector is used to receive X-rays and transmit X-ray imaging data; as well as An external exposure control unit for electrically activating the separate X-ray source and the X-ray flat panel detector when the X-ray tube focus on the separate X-ray source moves in a direction opposite to that of the elementary motor stage and at a selected speed of the elementary motor stage.

2. The system of claim 1, comprising a pair of electrical deflection plates on each X-ray tube of the X-ray source.

3. The system of claim 1, comprising one or a pair of magnetic deflection coil yokes on each of the X-ray tubes of the X-ray source.

4. The system of claim 1, wherein one or more of the X-ray sources are activated using a predetermined protocol.

5. The system of claim 1, wherein the initial spatial position of the elementary motor stage is adjustable via software.

6. The system of claim 1, wherein the result of each and cumulative analysis of the X-ray imaging data determines the next X-ray source and exposure conditions.

7. The system of claim 1, wherein the exposure time of the X-ray source is adjustable via software.

8. The system of claim 1, wherein an object scanned by the system is stationary.

9. The system of claim 1, wherein the X-ray tube focal spot is moved a small distance about a static position on an X-ray tube target by a deflection electric field or a deflection magnetic field.

10. The system of claim 1 , wherein the individual X-ray sources are triggered by an external exposure control unit when the X-ray tube focus on the individual X-ray sources has a speed equal to the speed of the grouped X-ray sources but an opposite direction of movement, and wherein the X-ray sources remain relatively stationary during the X-ray pulse triggering exposure duration.

11. A method of rapid 3D radiography with multiple pulsed X-ray sources by using electromagnetic field to deflect tube electron beams, wherein: Each X-ray tube in the X-ray source has a pair of electric deflection plates and one or a pair of deflection magnetic coil yokes, and the method comprises: positioning a primary motor table driven by a primary motor to a predetermined initial position; sweeping the elementary motor table at a predetermined constant speed by the elementary motor; Deflecting the X-ray tube electron beam in a predetermined sequence by applying voltage to the electric deflection plates or current to the deflection magnetic coil yoke; electrically activating an X-ray source and an X-ray flat panel detector when an X-ray tube focal point of the X-ray source moves in a direction opposite to the direction of the elementary motor stage and at a selected speed of the elementary motor stage; and Image data is acquired from the X-ray flat panel detector.

12. The method of claim 11, wherein 4D imaging is performed by adding a time component to the 3D spatial imaging data.

13. The method according to claim 11, comprising: Vary the sweep angle based on the area of ​​interest.

14. The method of claim 11, wherein the X-ray imaging data is acquired and reconstructed in real time to determine the next X-ray source and exposure conditions.

15. The method according to claim 11, comprising: The X-ray source voltage input is varied during the sweep based on the density of the object to be scanned.

16. The method of claim 11, wherein the X-ray flat panel detector is coupled to a linear stage to adjust positioning based on a position of an X-ray source.

17. The method of claim 11, wherein the X-ray tube focal point is moved a small distance about a static position on an X-ray tube target by deflecting an electric field or a magnetic field.

18. The method of claim 11, wherein the individual X-ray sources are triggered by an external exposure control unit when the X-ray tube focus on the individual X-ray sources has a speed equal to the speed of the grouped X-ray sources but an opposite direction of movement, and wherein the X-ray sources remain relatively stationary during the X-ray pulse triggering exposure duration.

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