Abstract:
An inspection device for quarantine that includes a dual-energy CT apparatus capable of distinguishing substances, a DR apparatus, a substance identification system capable of enhancing display of an object (plant, animal, meat, etc.) focused for quarantine and automatically so labeling, and an image processing system capable of highlighting a suspect of quarantine and providing a corresponding automatic alarm. Compared to the prior art, the present disclosure can highlight a focused object for quarantine, which may improve accuracy and efficiency of inspection for quarantine at a port.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to the field of radiation imaging detection, and in particular, to inspection devices for quarantine. 
       BACKGROUND 
       [0002]    Perspective imaging is a desired means of imaging in the field of security. A DECT (Dual-Energy Computed Tomography) technology based on DR (Digital-Radiography) and CT (Computed Tomography) may obtain an effective atomic number and/or an equivalent density within a scanned object while 3D structure information of the scanned object is acquired, and DECT technology is an advantageous technology for substance identification. 
       SUMMARY 
       [0003]    A traditional dual-energy CT inspection device generally distinguishes substances to be scanned into three categories of inorganics (or metal), organics, and mixture, mainly for identifying objects such as explosives and/or drugs. For the field of quarantine, however, objects on which inspection in ports focuses, most objects are plants, animals and their products and so on, such as mammals, birds, fish and other pets, meat and meat products, aquatic products, fresh fruits, vegetables, seedlings, flowers and other plant material capable of reproduction, etc., which may have a significant impact on ecological security. 
         [0004]    The above objects on which quarantine inspection focuses are mostly organic. Since attenuation coefficients of X-rays in most organics is low, there may be a problem with a common CT inspection device that an area of an organic material has high brightness and low contrast in an image obtained from a common CT inspection device, which causes great difficulty in distinguishing organics using a common CT image. Therefore, an experienced image judging officer is usually required to judge whether organics belong to contraband. However, since there is significant difference between skill levels of image judging officers, and artificial image judgment results are easily influenced by subjective factors, a high false positive rate is easily caused. 
         [0005]    In order to solve one or more of the above problems, the present disclosure provides inspection devices for quarantine. 
         [0006]    In a first aspect of the present disclosure, an inspection device for quarantine is provided. The inspection device for quarantine includes a bearing mechanism configured to bear an object being scanned; a first X-ray source arranged at a side of the bearing mechanism and configured to emit X-rays substantially perpendicular to a movement direction of the bearing mechanism; a first detection and data collection apparatus arranged at another side of the bearing mechanism opposite to the first X-ray source, wherein an inspection area is formed between the first X-ray source and the bearing mechanism; a controller connected to the bearing mechanism, the first X-ray source and the first detection and data collection apparatus, and configured to control the bearing mechanism and the first X-ray source to perform a CT scan on the object being scanned; and a computer connected to the controller and the first detection and data collection apparatus, and configured to store data obtained by the CT scan, perform image reconstruction, identify a concerning substance for quarantine, and output an identification result of the concerning substance for quarantine. 
         [0007]    According to an embodiment of the present disclosure, the inspection device further includes a second X-ray source arranged in parallel with the first X-ray source, which is arranged at the side of the bearing mechanism and configured to emit X-rays substantially perpendicular to a movement direction of the bearing mechanism; a second detection and data collection apparatus, arranged at the other side of the bearing mechanism opposite to the second X-ray source, wherein an inspection area is formed between the second X-ray source and the bearing mechanism; wherein the controller is connected to the second X-ray source and the second detection and data collection apparatus, and controls the second X-ray source and the second detection and data collection apparatus to perform a transmission scan on the object being scanned; and the computer is connected to the second detection and data collection apparatus, and stores data obtained by the transmission scan. 
         [0008]    According to an embodiment of the present disclosure, the controller is connected to the bearing mechanism, the first X-ray source, the second X-ray source, the first detection and data collection apparatus and the second detection and data collection apparatus by a control line, and controls the CT scan and the transmission scan to be performed synchronously. 
         [0009]    According to an embodiment of the present disclosure, the controller is connected to the first X-ray source and the first detection and data collection apparatus, so that the first X-ray source emits continuous energy spectrum X-rays for performing a dual-energy CT scan or a multi-energy CT scan in combination with a dual-energy detector or an energy spectrum detector; or so that the first X-ray source emits high and low energy X-rays for performing a dual-energy CT scan. 
         [0010]    According to an embodiment of the present disclosure, the X-ray source is a single X-ray source point or distributed X-ray sources. 
         [0011]    According to an embodiment of the present disclosure, the first X-ray source and the first detection and data collection apparatus are arranged opposite to each other, implementing a CT structure with a gantry or a CT structure without a gantry. 
         [0012]    According to an embodiment of the present disclosure, the computer has functions of enhancing display of an object focused in quarantine, automatic labeling, highlighting a suspect object focused in quarantine, and automatic alarming. 
         [0013]    According to an embodiment of the present disclosure, the computer can automatically hide one or more non-organic components in the object being scanned when a reconstructed image is displayed. 
         [0014]    According to an embodiment of the present disclosure, the computer identifies and distinguishes organics, and automatically labels the object focused in quarantine. 
         [0015]    According to an embodiment of the present disclosure, the computer can automatically segment mixed objects being scanned into separated articles. 
         [0016]    According to an embodiment of the present disclosure, the computer highlights the suspect object focused in quarantine according to a 3D shape of the article in connection with a substance identification result, and alarms automatically. 
         [0017]    According to an embodiment of the present disclosure, the computer automatically records shape features of contrabands which are frequently labeled by a user. 
         [0018]    According to an embodiment of the present disclosure, the computer is connected to a cloud server, and uploads inspection data to the cloud server or updates a database from the cloud server. 
         [0019]    The inspection devices may be used for providing a 3D image of the object being scanned, performing substance identification on the object being scanned, and automatically labeling a substance focused in quarantine. Additionally, the inspection devices can highlight the suspect object focused in quarantine according to the 3D image, so that the image may be judged more intuitively. By using the inspection device, accuracy and efficiency of inspection for quarantine at a port can be improved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  shows a schematic diagram of an inspection device according to an embodiment of the present disclosure; 
           [0021]      FIG. 2  shows a schematic structure diagram of a computer in the inspection device as shown in  FIG. 1 ; 
           [0022]      FIG. 3  shows a schematic structure diagram of a controller in an inspection device according to an embodiment of the present disclosure; 
           [0023]      FIG. 4  shows a schematic diagram of an inspection device according to another embodiment of the present disclosure; and 
           [0024]      FIG. 5  shows a schematic structure diagram of the inspection device as shown in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. Although shown in different drawings, the same reference numbers represent the same or similar components. For clarity and conciseness, descriptions of well-known functions and structures will be omitted here to avoid obscuring the subject matter of the present disclosure. Embodiments below are used for explaining the present disclosure, but do not limit the scope of the present disclosure. 
         [0026]      FIG. 1  shows a schematic diagram of an inspection device according to an embodiment of the present disclosure. As shown in  FIG. 1 , the inspection device according to the present embodiment is, in particular, a CT device for the field of quarantine. The CT device may include a gantry  20 , a bearing mechanism  40 , a controller  50 , a computer  60 , etc. The gantry  20  may include a ray source  10  for emitting X-rays, such as an X-ray machine, and a detection and collection apparatus  30 . In some embodiments, the X-ray source may be enabled to emit continuous energy spectrum X-rays, and to perform a dual-energy CT scan or a multi-energy CT scan in combination with a dual-energy detector or an energy spectrum detector. In some embodiments, the X-ray source may be a dual-energy X-ray source, and the detector may also receive dual-energy or multi-energy X-rays, so as to perform a dual-energy X-ray inspection on an object  70  being scanned. 
         [0027]    The bearing mechanism  40  bears the object  70  being scanned to go through a scan area between the ray source  10  and the detection and collection apparatus  30  of the gantry  20 , during which the gantry  20  rotates around a heading direction of the object  70  being scanned so that the rays emitted from the ray source  10  can pass through the object  70  being scanned for performing the CT scan on the object  70  being scanned. The CT scan performed here may be a spiral scan, or a circular scan, or the like. 
         [0028]    The detection and collection apparatus  30  may be a detector and a data collector in an integrated module structure, e.g., an array detector, which may be used for detecting the rays passing through an article being scanned so as to obtain an analog signal, and for converting the analog signal to a digital signal, thereby outputting projection data of the object  70  being scanned for the X-rays. 
         [0029]    The controller  50  controls various components of the whole system to work synchronously. The computer  60  processes and reconstructs data collected by the data collector, and outputs the result. For example, after the object  70  being scanned is scanned successively by the CT device, the obtained dual-energy 3D image data are input to the computer  60 ; a substance identification system installed in the computer  60  performs substance identification on the object  70  being scanned according to the image data so as to obtain feature information of the substance, such as an equivalent atomic number, density etc., and tints the 3D image, automatically labeling the article which is judged as an object focused in quarantine (plant, animal, meat, etc.). 
         [0030]    As shown in  FIG. 1 , the ray source  10  is arranged at one side of the object  70  being scanned; and the detection and collection apparatus  30 , including the detector and the data collector, is arranged at another side of the object  70  being scanned and is used for obtaining transmission data and/or multi-angle projection data of the object  70  being scanned. A data amplifying circuit is included in the data collector, which may work in a (current) integrated mode or a pulse (counting) mode. A data output cable of the detection and collection apparatus  30  is connected to the controller  50  and the computer  60 , and the collected data are stored in the computer  60  according to a trigger command. Although a CT structure with a gantry is used in the illustrated embodiment, it will be understood by the skilled in the art that the ray source and the detector may utilize a CT structure without a gantry in other embodiments. 
         [0031]      FIG. 2  shows a schematic structure diagram of a computer  60  as shown in  FIG. 1 . As shown in  FIG. 2 , the data collected by the data collector are stored in a memory  61  via an interface unit  68  and a bus  64 . Configuration data and program of a computer data processor are stored in a ROM (Read-Only Memory)  62 . A RAM (Random-Access Memory)  63  is used for temporarily storing various data during operations of a processor  66 . In addition, computer programs for data processing are also stored in the memory  61 , e.g., a substance identification program, an image processing program, etc. The internal bus  64  connects the memory  61 , the ROM  62 , the RAM  63 , an input apparatus  65 , the processor  66 , a display apparatus  67  and the interface unit  68 . 
         [0032]    After the user inputs an operation instruction by the input apparatus  65  such as a keyboard and a mouse, instruction codes of the computer programs instruct the processor  66  to execute a predetermined data processing algorithm; and to display a data processing result on the display apparatus  67  such as a LCD display or to output the processing result directly in a form of a hard copy, such as printing, after the data processing result is obtained. 
         [0033]    The projection data obtained by the detection and collection apparatus  30  are stored in the computer  60  for reconstruction of the CT image, so as to obtain slice image data of the object  70  being scanned. Then, the computer  60  extracts a 3D shape parameter of at least one article of the object  70  being scanned from the slice image data, for providing a judgment basis for judging whether the object  70  to be scanned is contraband. According to other embodiments, the CT imaging system as illustrated above also may be a dual-energy CT system, i.e., the X-ray source  10  on the gantry  20  may emit high-energy rays and low-energy rays. After the detection and collection apparatus  30  detects projection data at different energy levels, dual-energy CT reconstruction may be performed by the computer data processor  60  to obtain the equivalent atomic numbers and/or density data of various slices of the object  70  being scanned. In this case, the computer  60  may obtain a substance attribute of the object  70  being scanned, e.g. a plant or meat, for providing a judgment basis for judging whether the object  70  to be scanned is contraband. 
         [0034]      FIG. 3  shows a schematic structure diagram of a controller according to an embodiment of the present disclosure. As shown in  FIG. 3 , the controller  50  includes: a control unit  51 , configured to control the ray source  10 , the bearing mechanism  40  and the detection and collection apparatus  30  according to instructions from the computer  60 ; a trigger signal generation unit  52 , configured to generate a trigger command for triggering actions of the ray source  10 , the detection and collection apparatus  40  and the bearing mechanism  40  under control of the control unit; a first driving device  53 , configured to drive the bearing mechanism  40  to convey the object  70  being scanned according to the trigger command generated by the trigger signal generation unit  52  under the control of the control unit  51 ; and a second driving device  54 , configured to drive the gantry  20  to rotate according to the trigger command generated by the trigger signal generation unit  52  under the control of the control unit  51 . The projection data obtained by the detection and collection apparatus  30  are stored in the computer  60  for reconstruction of the CT data, so as to obtain the slice image data of the object  70  being scanned. Then, the computer  60  identifies the atomic number of the substance by executing software, facilitating the work of the image judging officer. According to other embodiments, the CT imaging system as illustrated above may also be a dual-energy CT system, i.e., the X-ray source  10  on the gantry  20  may emit high-energy rays and low-energy rays. After the detection and collection apparatus  30  detects the projection data at different energy levels, the dual-energy CT reconstruction may be performed by the computer  60  to obtain the equivalent atomic numbers and/or density data of various slices of the object  70  being scanned. 
         [0035]      FIG. 4  shows a schematic diagram of an inspection device according to another embodiment of the present disclosure. In the embodiment as shown in  FIG. 4 , an object  410  being scanned is placed on a bearing structure  400  for inspection, which sequentially passes through a DR system  420  and a dual-energy CT system  430 . In the embodiment as shown in  FIG. 4 , the dual-energy CT system  430  and the DR system  420  may be operated synchronously. 
         [0036]      FIG. 5  shows a schematic structure diagram of the inspection device as shown in  FIG. 4  in detail. The inspection device as shown in  FIG. 5  includes a DR system on the left and a dual-energy CT system on the right, both of which share a bearing mechanism  530 , such as a belt, bearing an object  513  being scanned to move ahead. 
         [0037]    An X-ray source  511  for DR emits X-rays  512 , which transmit through the object  513  being scanned on the bearing mechanism  530 ; a transmission signal is received by a detector module  514 ; an analog signal is converted by a collection circuit  515  into a digital signal, which is transmitted to a controller  517  and a computer  518 , etc. A transmission image of the object  513  being scanned is obtained in the computer  518 , which is stored in a memory or is displayed. 
         [0038]    In some embodiments, the ray source  511  may include a single X-ray source point, or include a plurality of X-ray generators, e.g., distributed X-ray sources including a plurality of X-ray source points. 
         [0039]    As shown in  FIG. 5 , the bearing mechanism  530  bears the object  513  being scanned to go through a scan area between the ray source  511  and the detector  514 . In some embodiments, the detector  514  and the collection circuit  515  are a detector and a data collector in an integrated module structure, e.g., a plurality of detectors, for detecting the rays passing through an article being scanned so as to obtain the analog signal, and for converting the analog signal to the digital signal, thereby outputting projection data of the object  513  being scanned for the X-rays. The controller  517  controls various components of the whole system to work synchronously. The computer  518  processes and reconstructs data collected by the data collector, and outputs the result. 
         [0040]    According to the embodiment, the detector  514  and the collection circuit  515  are used for obtaining transmission data of the object  513  being scanned. A data amplifying circuit is included in the collection circuit  515 , which may work in a (current) integrated manner or a pulse (counting) manner. The collection circuit  515  is connected to the controller  517  and the computer  518 , and the collected data are stored in the computer  60  according to a trigger command. 
         [0041]    In some embodiments, the detector module  514  may include a plurality of detection units for receiving the X-rays which pass through the object being scanned. The data collection circuit  515  is coupled to the detector module  514  for converting a signal generated by the detector module  514  to detection data. The controller  517  is connected via a control line CTRL 11  to the ray source  511  and is connected via a control line CTRL 12  to the detector module  514  which is in turn connected to the data collection circuit  515 , so as to control at least one X-ray generator of the ray source to generate the X-rays which are emitted for passing through the object being scanned as the object being scanned moves. In addition, the controller  517  controls the detector module  514  and the data collection circuit  515  to obtain the detection data. The computer  518  reconstructs the image of the object being scanned based on the detection data. 
         [0042]    As the object being scanned moves ahead, the dual-energy CT system performs the CT scan on the object being scanned. A X-ray source  521  for CT emits X-rays  522 , which pass through the object  513  being scanned on the bearing mechanism  530 . As the object moves forward, the ray source  521  and a detector  524  are rotated for the CT scan, a projection signal is received by the detector module  524 , an analog signal is converted by a collection circuit  525  into a digital signal, which is sent to the controller  517  and the computer  518 , etc. Slice images of the object  513  being scanned are obtained in the computer  518 , which are stored in the memory or are displayed. 
         [0043]    In some embodiments, the detector module  524  includes a plurality of detection units for receiving the X-rays which pass through the object being scanned. The data collection circuit  525  is coupled to the detector module  524  for converting a signal generated by the detector module  524  to detection data. The controller  517  is connected via a control line CTRL 21  to the ray source  521  and is connected via a control line CTRL 22  to the detector module  524  which is in turn connected to the data collection circuit  525 , so as to control two high and low energy X-ray generators of the ray source to alternately generate high and low energy X-rays which are emitted for passing through the object being scanned as the object being scanned moves, achieving a dual-energy CT scan. In addition, the controller  517  controls the detector module  524  and the data collection circuit  525  to obtain the projection data. The computer  518  reconstructs the image of the object being scanned based on the projection data, and performs the substance identification. 
         [0044]    For example, in the embodiment as shown in  FIG. 4 , the object  410  being scanned goes through the DR system  420  and the dual-energy CT system  430  sequentially, and the obtained 2D and dual-energy 3D image data are input to the computer for substance identification. The substance identification system installed in the computer performs substance identification on the object being scanned according to the image data so as to obtain information of different substances, such as the equivalent atomic numbers, densities, etc., and tints the 2D image and the 3D image, automatically labeling the article which is judged as the object focused in quarantine (plant, animal, meat, etc.). 
         [0045]    In an embodiment of the present disclosure, the substance identification system may hide a part of the object being scanned which is identified to be inorganic, so as to highlight one or more organic components of the object being scanned. 
         [0046]    In an embodiment of the present disclosure, the substance identification system may further identify and distinguish organics more accurately, respectively labeling plants, animals, meat and their products, etc. with different colors. In addition, the image which has been labeled by substance identification is input to the image processing system in the computer  518 , which in turn highlights the suspect of quarantine, and alarms automatically. 
         [0047]    In an embodiment of the present disclosure, the image processing system in the computer  518  may automatically segment the image of the object being scanned which comprises a mixture of various kinds of articles into separate articles according to their profile edges, facilitating the inspection officer to judge the image. 
         [0048]    In an embodiment of the present disclosure, the image processing system in the computer  518  may compare an appearance of the 3D image of the object being scanned with a suspect image database in connection with the substance identification result, and further highlight the suspect of quarantine, so as to improve accuracy of an automatic alarm. 
         [0049]    In an embodiment of the present disclosure, the image processing system in the computer  518  may have a self-learning function, and may automatically identify shape features of contrabands which are frequently labeled by a user and record them in the database, so as to improve accuracy of the automatic alarm. 
         [0050]    In an embodiment of the present disclosure, the image processing system in the computer  518  may be configured with a cloud data collection function, e.g., may be connected to a cloud server for uploading the inspection data to the cloud server. The user may authorize different image read rights of the cloud server to different persons, or enable the image read rights of the cloud server to have access to another management system. 
         [0051]    In an embodiment of the present disclosure, the image processing system in the computer  518  may be configured with a database cloud update function, e.g., may be connected to the cloud server for updating an alarm database from the cloud. 
         [0052]    Although the inspection device for quarantine according to the present disclosure is described in connection with particular embodiments, the skilled in the art may apply the inspection device to other fields for solving an inspection problem in other industries. Therefore, various modifications, improvements, expansions and applications which can be made by those skilled in the art based on the embodiments of the present disclosure are to be encompassed by the scope of the present disclosure as defined by the claims and their equivalents.