X-ray photography control device

Abstract

To enhance accuracy in X-ray control.SOLUTION: An X-ray imaging control device includes a selection section, an acquisition section, a comparison section, and an X-ray control section, so as to control X-ray imaging in an X-ray diagnostic apparatus including: an X-ray generation section for generating an X-ray; an X-ray detection section where detection elements to detect the X-ray and to output a detection signal are arranged in a matrix state; and an image generation section for generating an X-ray image based on the detection signals. The selection section selects a plurality of element arrays where the detection elements are arranged in a row state from the detection elements included in the X-ray detection section. The acquisition section acquires detection signal patterns indicating the patterns of the detection signals for each element array. The comparison section compares the detection signal patterns with a standard signal pattern for each element array. The X-ray control section performs X-ray control based on a comparison result by the comparison section and the detection signals detected in the plurality of element arrays.SELECTED DRAWING: Figure 8B

Description

[Technical field]

[0001] The embodiments disclosed in this specification relate to an X-ray imaging control device. [Background technology]

[0002] In X-ray photography, it is necessary to appropriately control X-rays, taking into consideration the amount of radiation exposure to the subject and the image quality of the X-ray image. For example, if the X-rays irradiated to the subject are insufficient, the image quality required for image diagnosis cannot be obtained, and exposure to excessive X-rays places a burden on the subject. In addition, since there are individual differences in the body thickness and internal structure of subjects, it is necessary to control X-rays individually for each subject. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-211514 A [Patent Document 2] JP 2013-176544 A [Patent Document 3] JP 2012-159497 A [Patent Document 4] JP 2005-6196 A Summary of the Invention [Problem to be solved by the invention]

[0004] One of the problems that the embodiments disclosed in this specification are intended to solve is to improve the accuracy of X-ray control. However, the problems solved by the embodiments disclosed in this specification are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be considered as other problems solved by the embodiments disclosed in this specification. [Means for solving the problem]

[0005] The X-ray photography control device of the embodiment includes a selection unit, an acquisition unit, a comparison unit, and an X-ray control unit, and controls X-ray photography in an X-ray diagnostic device including an X-ray generation unit that generates X-rays, an X-ray detection unit in which detection elements that detect the X-rays and output detection signals are arranged in a matrix, and an image generation unit that generates an X-ray image based on the detection signals. The selection unit selects a plurality of element rows in which detection elements are arranged in a row from among the detection elements included in the X-ray detection unit. The acquisition unit acquires a detection signal pattern indicating a pattern of the detection signals for each of the element rows. The comparison unit compares the detection signal pattern with a standard signal pattern for each of the element rows. The X-ray control unit controls the X-rays based on a comparison result by the comparison unit and the detection signals detected in the plurality of element rows. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of an X-ray diagnostic apparatus according to the first embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of the configuration of the X-ray imaging control device according to the first embodiment. [Diagram 3] FIG. 3 is a diagram showing an overview of X-ray imaging according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of an AEC detector according to the first embodiment. [Figure 5A] FIG. 5A is a diagram for explaining AEC using a detection signal of the X-ray detector according to the first embodiment. [Figure 5B] FIG. 5B is a diagram for explaining AEC using the detection signal of the X-ray detector according to the first embodiment. [Figure 5C] FIG. 5C is a diagram for explaining AEC using the detection signal of the X-ray detector according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing a series of processes of the X-ray imaging control device according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a region of interest and an element array according to the first embodiment. [Figure 8A] FIG. 8A is a diagram for explaining the process of comparing a detection signal pattern with a standard signal pattern according to the first embodiment. [Figure 8B] FIG. 8B is a diagram for explaining the process of comparing the detection signal pattern with the standard signal pattern according to the first embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of a region of interest and an element array according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of a region of interest and an element array according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment of an X-ray imaging control device will be described in detail with reference to the drawings.

[0008] (First embodiment) An X-ray diagnostic apparatus 1 including an X-ray photography control device 12 will be described as an example. For example, as shown in Fig. 1, the X-ray diagnostic apparatus 1 includes an X-ray high voltage device 11, an X-ray photography control device 12, an X-ray tube 13, an X-ray aperture 14, an X-ray detector 15, an input interface 16, a display 17, a memory 18, and a processing circuit 19. Fig. 1 is a block diagram showing an example of the configuration of the X-ray diagnostic apparatus 1 according to the first embodiment.

[0009] The X-ray high voltage device 11 is a device that supplies a high voltage to the X-ray tube 13. For example, the X-ray high voltage device 11 has electric circuits such as a transformer and a rectifier, and includes a high voltage generating device that generates a high voltage to be applied to the X-ray tube 13, and a control device that controls the output voltage according to the X-rays irradiated by the X-ray tube 13. The high voltage generating device may be of a transformer type or an inverter type.

[0010] The X-ray photography control device 12 is a device that controls X-ray photography in the X-ray diagnostic apparatus 1. For example, the X-ray photography control device 12 controls the supply of high voltage from the X-ray high voltage device 11 to the X-ray tube 13 based on a detection signal output from the X-ray detector 15, and controls the on / off switching of X-rays. The X-ray photography control device 12 will be described in detail later.

[0011] X-ray tube 13 is a vacuum tube having a cathode (filament) that generates thermoelectrons and an anode (target) that generates X-rays upon impact of the thermoelectrons. X-ray tube 13 generates X-rays by irradiating thermoelectrons from the cathode to the anode using a high voltage supplied from X-ray high voltage device 11. X-ray tube 13 is an example of an X-ray generating unit.

[0012] The X-ray aperture 14 has a collimator that narrows down the irradiation range of the X-rays, and a filter that adjusts the radiation quality and dose of the X-rays. For example, the collimator has four slidable aperture blades, and by sliding these aperture blades, the X-rays generated by the X-ray tube 13 are narrowed down and irradiated to the subject P. Here, the aperture blades are plate-shaped members made of lead or the like, and are provided near the X-ray irradiation port of the X-ray tube 13 to adjust the irradiation range of the X-rays. In addition, the filter changes the radiation quality of the transmitted X-rays depending on its material and thickness, and reduces soft ray components that are easily absorbed by the subject P and high energy components that cause a decrease in contrast of the X-ray image, for the purpose of reducing the radiation dose to the subject P and improving the image quality of the X-ray image. In addition, the filter changes the dose and irradiation range of the X-rays depending on its material, thickness, position, etc., and attenuates the X-rays so that the X-rays irradiated to the subject P have a predetermined distribution.

[0013] For example, the X-ray aperture 14 has a driving mechanism such as a motor and an actuator, and controls the collimator and the filter by operating the driving mechanism under the control of the processing circuitry 19 described later. For example, the X-ray aperture 14 applies a driving voltage to the driving mechanism in response to a control signal received from the processing circuitry 19 to adjust the opening of the aperture blades of the collimator and control the irradiation range of the X-rays irradiated to the subject P. Also, for example, the X-ray aperture 14 applies a driving voltage to the driving mechanism in response to a control signal received from the processing circuitry 19 to adjust the position of the filter, thereby controlling the radiation quality and dose distribution of the X-rays irradiated to the subject P.

[0014] The X-ray detector 15 is, for example, an X-ray flat panel detector (FPD) having detection elements arranged in a matrix. Each detection element in the X-ray detector 15 detects X-rays irradiated from the X-ray tube 13 and transmitted through the subject P, and outputs a detection signal corresponding to the detected X-ray amount. Here, a part of the detection signal output from the detection element of the X-ray detector 15 is used for X-ray control by the X-ray imaging control device 12, and the other part is used for generating an X-ray image. The X-ray detector 15 may be an indirect conversion type detector having a grid, a scintillator array, and a photosensor array, or may be a direct conversion type detector having a semiconductor element that converts the incident X-ray into an electric signal. The X-ray detector 15 is an example of an X-ray detection unit.

[0015] The input interface 16 receives various input operations from a user, converts the received input operations into electrical signals, and outputs the electrical signals to the processing circuitry 19. The user may be a doctor or technician in charge of the subject P. For example, the input interface 16 may be realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touchpad that performs input operations by touching an operation surface, a touch screen in which a display screen and a touchpad are integrated, a non-contact input circuit using an optical sensor, a voice input circuit, or the like. The input interface 16 may be configured as a tablet terminal or the like capable of wireless communication with the processing circuitry 19. The input interface 16 may also be a circuit that receives input operations from a user by motion capture. For example, the input interface 16 can receive the user's body movements, gaze, and the like as input operations by processing signals acquired via a tracker and images collected about the user. The input interface 16 is not limited to being equipped with physical operation parts such as a mouse and a keyboard. For example, an example of the input interface 16 also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the X-ray diagnostic apparatus 1 and outputs this electrical signal to the processing circuit 19.

[0016] The display 17 displays various types of information. For example, the display 17 displays an X-ray image of the subject P. Also, for example, the display 17 displays a GUI (Graphical User Interface) for receiving user instructions under the control of the processing circuitry 19. For example, the display 17 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 17 may be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the processing circuitry 19.

[0017] 1, the X-ray diagnostic apparatus 1 is described as having the display 17, but the X-ray diagnostic apparatus 1 may have a projector instead of or in addition to the display 17. The projector can project onto a screen, a wall, a floor, the body surface of the subject P, etc. under the control of the processing circuitry 19. As an example, the projector can also project onto any plane, object, space, etc. by projection mapping.

[0018] The memory 18 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory), a flash memory, a hard disk, an optical disk, etc. For example, the memory 18 receives and stores an X-ray image generated by the processing circuitry 19. The memory 18 also stores programs corresponding to various functions that are read out and executed by the processing circuitry 19.

[0019] The processing circuitry 19 executes a control function 191, an image generation function 192, and an output function 193 to control the operation of the entire X-ray diagnostic apparatus 1. For example, the processing circuitry 19 reads out a program corresponding to the control function 191 from the memory 18 and executes it to control various functions such as the image generation function 192 and the output function 193 based on various input operations received from a user via the input interface 16.

[0020] The control function 191 also controls various imaging conditions. For example, the control function 191 adjusts the voltage supplied from the X-ray high voltage device 11 to the X-ray tube 13 to control the X-ray dose. The control function 191 also controls the operation of the X-ray aperture 14 to adjust the opening of the aperture blades of the collimator to control the X-ray irradiation range. The control function 191 also controls the operation of the X-ray aperture 14 to adjust the position of the filter to control the distribution of the X-ray dose and radiation quality.

[0021] Moreover, the processing circuitry 19 reads out from the memory 18 a program corresponding to the image generating function 192 and executes it to generate an X-ray image based on the detection signal received from the X-ray detector 15, and stores the generated X-ray image in the memory 18. Furthermore, the image generating function 192 may perform various image processing on the generated X-ray image. For example, the image generating function 192 performs noise reduction processing and scattered radiation correction using an image processing filter on the generated X-ray image.

[0022] Also, for example, the processing circuitry 19 outputs an X-ray image by reading and executing a program corresponding to the output function 193 from the memory 18. For example, the output function 193 causes the display 17 to display the X-ray image generated by the image generation function 192. Also, for example, the output function 193 transmits the X-ray image generated by the image generation function 192 to an image storage device via the network NW.

[0023] The network NW may be a local network. For example, the network NW may be a local area network (LAN) that is closed within a hospital. Alternatively, the network NW may be a network connected via the Internet.

[0024] 1, each processing function is stored in the memory 18 in the form of a program executable by a computer. The processing circuitry 19 is a processor that realizes a function corresponding to each program by reading and executing the program from the memory 18. In other words, the processing circuitry 19 in a state in which a program has been read has a function corresponding to the read program.

[0025] 1, the control function 191, the image generating function 192, and the output function 193 are realized by a single processing circuit 19. However, the processing circuit 19 may be configured by combining a plurality of independent processors, and each processor may execute a program to realize the functions. Furthermore, each processing function of the processing circuit 19 may be realized by being appropriately distributed or integrated in a single or a plurality of processing circuits.

[0026] The processing circuitry 19 may also realize the functions by using a processor of an external device connected via a network NW. For example, the processing circuitry 19 reads out and executes a program corresponding to each function from the memory 18, and realizes each function shown in FIG. 1 by using a server group (cloud) connected to the X-ray diagnostic apparatus 1 via the network NW as a computational resource.

[0027] Next, the X-ray imaging control device 12 will be described with reference to FIG. 2. FIG. 2 is a block diagram showing an example of the configuration of the X-ray imaging control device 12 according to the first embodiment. The X-ray imaging control device 12 has a processing circuit 121 and a memory 122. The processing circuit 121 controls X-ray imaging in the X-ray diagnostic device 1 by executing a selection function 121a, an acquisition function 121b, a comparison function 121c, and an X-ray control function 121d. The selection function 121a is an example of a selection section. The acquisition function 121b is an example of an acquisition section. The comparison function 121c is an example of a comparison section. The X-ray control function 121d is an example of an X-ray control section.

[0028] For example, the processing circuit 121 reads out a program corresponding to the selection function 121a from the memory 122 and executes it to select a plurality of element rows in which detection elements are arranged in a row from among the detection elements included in the X-ray detector 15. The processing circuit 121 also reads out a program corresponding to the acquisition function 121b from the memory 122 and executes it to acquire a detection signal pattern indicating a pattern of a detection signal for each element row. The processing circuit 121 also reads out a program corresponding to the comparison function 121c from the memory 122 and executes it to compare the detection signal pattern with a standard signal pattern for each element row. The processing circuit 121 also reads out a program corresponding to the X-ray control function 121d from the memory 122 and executes it to control X-rays based on the comparison result by the comparison function 121c and the detection signals detected in the plurality of element rows. Details of each function of the processing circuit 121 will be described later.

[0029] The memory 122 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, a hard disk, an optical disk, etc. For example, the memory 122 stores weighting functions and standard signal patterns, which will be described later. The memory 122 also stores programs corresponding to various functions that are read out and executed by the processing circuit 121.

[0030] 2, each processing function is stored in the memory 122 in the form of a program executable by a computer. The processing circuitry 121 is a processor that realizes a function corresponding to each program by reading and executing the program from the memory 122. In other words, the processing circuitry 121 in a state in which a program has been read has a function corresponding to the read program.

[0031] 2, the selection function 121a, the acquisition function 121b, the comparison function 121c, and the X-ray control function 121d are realized by a single processing circuit 121. However, the processing circuit 121 may be configured by combining a plurality of independent processors, and each processor may execute a program to realize the functions. Furthermore, each processing function of the processing circuit 121 may be realized by being appropriately distributed or integrated in a single or a plurality of processing circuits.

[0032] The processing circuitry 121 may also realize functions by using a processor of an external device connected via a network NW. For example, the processing circuitry 121 reads out and executes a program corresponding to each function from the memory 122, and realizes each function shown in FIG. 2 by using a server group (cloud) connected to the X-ray imaging control device 12 via the network NW as a computational resource.

[0033] The above describes the overall configuration of the X-ray diagnostic apparatus 1 including the X-ray imaging control device 12. Next, an overview of X-ray imaging in the X-ray diagnostic apparatus 1 will be described with reference to FIG.

[0034] The X-ray imaging control device 12 controls the supply of high voltage from the X-ray high voltage device 11 to the X-ray tube 13, and switches X-rays on and off. When the X-ray imaging control device 12 turns X-rays "on", imaging is started. Also, while the X-ray imaging control device 12 controls X-rays to be "on", X-rays are irradiated from the X-ray tube 13 to the subject P, and the X-rays that have passed through the subject P are detected by the X-ray detector 15. Also, when the X-ray imaging control device 12 turns X-rays "off", imaging is ended. That is, the X-ray imaging control device 12 controls the imaging time by controlling the on / off switching of X-rays. Although not shown in FIG. 3, the control function 191 controls various imaging conditions such as the X-ray dose and irradiation range by controlling the operation of the X-ray high voltage device 11, the X-ray aperture 14, etc.

[0035] In the X-ray detector 15, the detection elements are arranged in a matrix to form an imaging area. For example, in the X-ray detector 15, the detection elements are arranged in "n" rows in the vertical direction and "m" columns in the horizontal direction in Fig. 3. The X-ray detector 15 realizes the detection of X-rays by the operation of a drive circuit and a readout circuit.

[0036] For example, while the X-ray imaging control device 12 controls the X-rays to be "on", each detection element accumulates electric charge according to the amount of X-rays irradiated. After the X-ray imaging control device 12 turns the X-rays "off", the control circuit operates the drive circuit and the readout circuit with the power supplied from the power source. The drive circuit sequentially transmits readout signals (G1-Gn). For example, the drive circuit transmits a readout signal G1 to the detection elements in the first row, transmits a readout signal G2 to the detection elements in the second row, and transmits a readout signal Gn to the detection elements in the nth row. The detection elements that receive the readout signal read out electric charge, and output a detection signal to the readout circuit. For example, when the readout signal G1 is transmitted, detection signals P(G1,1)-P(G1,m) are read out from the detection elements in the first row. Then, the readout circuit acquires detection signals P(G1,1)-P(G1,m) to P(Gn,1)-P(Gn,m) as a result of the readout signals (G1-Gn) being sequentially transmitted from the drive circuit. The signal processing circuit performs various pre-processing processes on the detection signals read out by the readout circuit. For example, the signal processing circuit performs amplification processing, A / D conversion, and the like on the detection signals. The pre-processed detection signals are transmitted to the processing circuit 19 via a wireless communication circuit or the like of the X-ray detector 15. The image generation function 192 of the processing circuit 19 generates an X-ray image based on the detection signals transmitted from the X-ray detector 15.

[0037] Here, the X-ray imaging control device 12 automatically determines the timing to turn off the X-rays. That is, the X-ray imaging control device 12 automatically controls the imaging time. Such an automatic control technology is also called Automatic Exposure Control (AEC).

[0038] AEC can be realized, for example, by further using an AEC detector shown in FIG. 4. A region of interest (ROI) is provided in the AEC detector. The position and size of the ROI in the AEC detector are empirically determined for each imaging region. For example, three ROIs (I to III) are provided in the AEC detector. The AEC detector is disposed between the subject P and the X-ray detector 15, and detects X-rays that have passed through the subject P. Then, AEC can be realized by turning off the X-rays when the amount of X-rays detected by the AEC detector exceeds a threshold value.

[0039] However, it is costly to add an AEC detector to the X-ray diagnostic apparatus 1. Also, the ROI in the AEC detector is placed at a predetermined position, and a different AEC detector must be prepared for each imaging region. Furthermore, the shape and size of the imaging region vary depending on the age and physique of the subject P, and the ROI in the AEC detector cannot be optimized for each imaging, so that the imaging time may not be appropriately controlled.

[0040] Also, a method for realizing AEC without using an AEC detector has been proposed. Specifically, it is possible to execute AEC by using a part of the detection signal detected by the X-ray detector 15 for AEC instead of as image information. Here, if a large number of detection elements are used for AEC, the image information is reduced, affecting the image quality, and the calculation load for AEC increases. Therefore, there is a limit to the number of detection elements that can be used for AEC, and it is necessary to treat the detection results of the limited number of detection elements as representative values.

[0041] A case where AEC is performed using a detection signal from the X-ray detector 15 will be described below with reference to Figs. 5A and 5B. For example, the X-ray imaging control device 12 selects elements to be used for AEC from among the detection elements of the X-ray detector 15 as shown in Fig. 5A. Specifically, the X-ray imaging control device 12 selects a portion of the elements included in the ROI as detection elements to be used for AEC, rather than all elements included in the ROI. More specifically, the X-ray imaging control device 12 selects elements in the G2 row, the G4 row, and the G6 row as detection elements to be used for AEC from among seven rows of detection elements from G1 to G7 included in the ROI (region of interest), as shown in the upper diagram of Fig. 5B.

[0042] Signals are read out from each detection element as shown in FIG. 5C. Specifically, after a preparation and waiting period, imaging is started and AEC (Automatic Exposure Control) is started. Next, at time t after imaging starts, detection signals are read out. Hereinafter, a detection signal read out from an element in the xth row at time t is referred to as a signal P(Gx,t). For example, a detection signal read out from an element in the G2 row at time t is referred to as a signal P(G2,t) as shown in the upper diagram of FIG. 5B.

[0043] Returning to FIG. 5C, the description continues. After the start of imaging, the readout of detection signals from each detection element selected as a detection element to be used for AEC is repeatedly performed. For example, at time "t=1", a signal P(G2,1) is read out from the element in the row G2, a signal P(G4,1) is read out from the element in the row G4, and a signal P(G6,1) is read out from the element in the row G6. At time "t=2", a signal P(G2,2) is read out from the element in the row G2, a signal P(G4,2) is read out from the element in the row G4, and a signal P(G6,2) is read out from the element in the row G6. At time "t=3", a signal P(G2,3) is read out from the element in the row G2, a signal P(G4,3) is read out from the element in the row G4, and a signal P(G6,3) is read out from the element in the row G6. The read signal is also compared to a threshold value.

[0044] For example, as shown in the lower diagram of Fig. 5B, the X-ray imaging control device 12 compares a signal P(G2,1) read from the elements in the G2 row at time "t=1" with a threshold value. Note that the signal P(G2,1) can be expressed as a pattern in which the detection signals read from the elements in the G2 row are associated with positions within the region of interest.

[0045] Next, the X-ray imaging control device 12 compares a signal "P(G2,1)+P(G2,2)" obtained by integrating the signal P(G2,2) read from the elements in the G2 row at time "t=2" with a threshold value. Next, the X-ray imaging control device 12 compares a signal "P(G2,1)+P(G2,2)+P(G2,3)" obtained by integrating the signal P(G2,3) read from the elements in the G2 row at time "t=3" with a threshold value. Next, the X-ray imaging control device 12 compares a signal "P(G2,1)+P(G2,2)+P(G2,3)+P(G2,4)" obtained by integrating the signal P(G2,4) read from the elements in the G2 row at time "t=4" with a threshold value. Next, the X-ray imaging control device 12 compares the signal P(G2,5) read from the elements in the G2 row at time "t=5" ("P(G2,1)+P(G2,2)+P(G2,3)+P(G2,4)+P(G2,5)") with a threshold value. When the integrated value of the signal exceeds the threshold value, the X-ray imaging control device 12 ends imaging and turns off the X-rays.

[0046] In addition, in the detection elements not used for AEC (the elements in the rows G1, G3, G5, and G7), charge continues to accumulate from the start of imaging to the end of imaging. The charges accumulated in these detection elements are read out as pixel signals after X-rays (radiation) are turned off, as shown in FIG. 5C, and are used to generate an X-ray image.

[0047] As described above, it is possible to perform AEC using the detection signal of the X-ray detector 15. However, in this case, since it is necessary to use the detection results of a limited number of detection elements for comparison with a threshold, the imaging time may be affected by a slight positional deviation with respect to the subject P. For example, when the lung field is the imaging region, a difference in signal value may occur depending on whether the detection element used for AEC overlaps with bone or soft tissue, and the imaging time may change.

[0048] Therefore, the X-ray imaging control device 12 improves the accuracy of X-ray control without using an additional AEC detector by the following process. The process performed by the X-ray imaging control device 12 will be described below with reference to the flowchart in FIG.

[0049] First, the selection function 121a acquires examination information of the subject P (step S101). The examination information includes, for example, patient information and imaging site. For example, the selection function 121a can automatically acquire the examination information from a system such as a Hospital Information System (HIS) or a Radiology Information System (RIS). Alternatively, the selection function 121a can acquire the examination information based on an input operation from a user.

[0050] Next, the selection function 121a acquires various information from the memory 122 based on the examination information (step S102). For example, the selection function 121a acquires information on the number and positions of ROIs that can be set on the detection surface of the X-ray detector 15. For example, the selection function 121a acquires the imaging site in step S101, and acquires information on the number and positions of ROIs associated with the imaging site. As an example, when the imaging site is the "lungs", the selection function 121a acquires "three" ROIs corresponding to the right lung, the left lung, and a position between both lungs, together with the position information of each ROI. The selection function 121a also acquires a weighting function and a standard signal pattern associated with each ROI. The weighting function and the standard signal pattern will be described later.

[0051] The selection function 121a also determines whether or not the subject P has had a previous examination (step S103), and if so (Yes in step S103), acquires the previous examination information of the subject P (step S104). The previous examination information includes, for example, the imaging site targeted in the previous examination, image information collected in the previous examination, and information on the number and positions of ROIs used in the previous examination. For example, the selection function 121a can automatically acquire the previous examination information from a system such as an HIS, RIS, or PACS (Picture Archiving and Communication System). The order in which steps S102 and S103 are performed is arbitrary, and they may be performed in parallel.

[0052] Next, the selection function 121a sets an ROI and selects a plurality of element rows within the ROI (step S105). For example, the selection function 121a displays the ROI acquired in step S102 on the display 17 and accepts an input operation from the user to set the ROI. Here, the selection function 121a may accept an operation to increase or decrease the number of ROIs or an operation to adjust the position of the ROI from the user. For example, the user adjusts the position of the ROI in consideration of the age, physique, etc. of the subject P. In addition, the selection function 121a selects a weighting function corresponding to the ROI set in step S105 from among the weighting functions acquired in step S102 as a weighting function to be used in step S110 described later.

[0053] If the subject P has had a previous examination, the selection function 121a sets the ROI taking into consideration the previous examination information. For example, if it is clear from image information collected in the previous examination that the subject P does not have a right lung, the selection function 121a excludes the ROI corresponding to the right lung from the three ROIs acquired in step S102. The selection function 121a may set the ROI according to reception information when the subject P visited the hospital or the results of a hearing from the subject P, instead of the previous examination information.

[0054] After setting the ROI, the selection function 121a selects multiple element rows within the ROI. For example, the selection function 121a intermittently selects multiple element rows from among the detection elements included in the ROI, similar to the case shown in FIG. 5B. Furthermore, when multiple ROIs are set, the selection function 121a selects multiple element rows for each ROI. The detection signals detected in the element rows selected in step S105 are used for AEC, not as image information.

[0055] Next, the X-ray control function 121d starts imaging and AEC (step S106). Specifically, the X-ray control function 121d starts the supply of high voltage from the X-ray high voltage device 11 to the X-ray tube 13 to turn on X-rays, and starts various processes from step S107 onwards.

[0056] The acquisition function 121b acquires the detection signals of the element rows in the ROI (step S107). Specifically, the acquisition function 121b acquires a detection signal pattern indicating the pattern of the detection signal for each element row. The detection signal pattern of each element row can be shown as a pattern in which the detection signal read out from each element in the element row is associated with a position in the region of interest, similar to the signal P(G2,1) shown in FIG. 5B. In other words, the detection signal pattern indicates the change in the detection signal along the element row.

[0057] Next, the comparison function 121c compares the standard signal pattern and the detection signal pattern acquired in step S102 for each element row, and determines whether there is a difference (step S108). If there is a difference between the standard signal pattern and the detection signal pattern (step S108: Yes), the comparison function 121c ignores the element row with the difference as an abnormal element row (step S109). On the other hand, if there is no difference between the standard signal pattern and the detection signal pattern (step S108: No), the X-ray control function 121d applies a weighting function to each detection signal (step S110). Also, if the abnormal element row is ignored in step S109, the X-ray control function 121d corrects the detection signals of the remaining element rows (step S111). Next, the X-ray control function 121d performs the weighting process in step S110 and accumulates each detection signal after the correction process in step S111 for each ROI (step S112). Next, the X-ray control function 121d judges whether there is a difference between the ROIs in the integrated values ​​calculated in step S112 (step S113), and if there is a difference (step S113: Yes), ignores the detection signal as an abnormal ROI (step S114). If the detection signal of the abnormal ROI was ignored in step S114, the X-ray control function 121d corrects the detection signal of the remaining ROI (step S115). Next, the X-ray control function 121d sums up all the ROI integrated values ​​(step S116), judges whether it is equal to or greater than a threshold (step S117), and if it is equal to or less than the threshold (step S117: No), proceeds to step S107 again. On the other hand, if the ROI integrated value exceeds the threshold (step S117: Yes), the X-ray control function 121d ends the imaging (step S118) and starts the readout operation of the X-ray detector 15 (step S119). Furthermore, the image generating function 192 generates an X-ray image based on the detection signal read out in step S119, and the output function 193 displays the X-ray image on the display 17 (step S120).

[0058] Hereinafter, the details of the process from step S108 to step S120 will be described with reference to Figures 7, 8A, and 8B. For example, when three regions of interest, region of interest R11, region of interest R12, and region of interest R13 in Figure 7, are set, the selection function 121a selects multiple element arrays for each region of interest. For example, the selection function 121a selects three element arrays for region of interest R13 as shown in Figure 8A.

[0059] The acquisition function 121b acquires a detection signal pattern for each of the three element rows. In Fig. 8A, the detection signal pattern is shown by a solid line graph. The horizontal axis of the graph indicates the horizontal position coordinate in the region of interest R13, and the vertical axis indicates the intensity of the detection signal output from the detection element at each position.

[0060] The comparison function 121c compares the detection signal pattern and the standard signal pattern for each element array. In FIG. 8A, the standard signal pattern is shown by a dashed line graph. FIG. 8A also shows a case where there is no difference between the detection signal pattern and the standard signal pattern in any of the three element arrays. That is, the case where there is no difference between the detection signal pattern and the standard signal pattern is not limited to a case where the detection signal pattern and the standard signal pattern exactly match, but also includes a case where they roughly match. As an example, the comparison function 121c calculates the KL divergence (Kullback-Leibler Divergence) between the detection signal pattern and the standard signal pattern and compares it with a threshold value, and if it does not exceed the threshold value, it determines that there is no difference between the detection signal pattern and the standard signal pattern.

[0061] The standard signal pattern is, for example, preset for each ROI and stored in the memory 122. For example, if AEC was previously performed using the same number and positions of regions of interest as those in Fig. 7, and X-rays were appropriately controlled by the AEC, the comparison function 121c can store the detection signal pattern actually collected in the AEC as the standard signal pattern in the memory 122. The standard signal pattern may also be manually set by the user.

[0062] Next, the X-ray control function 121d applies a weighting function to each detection signal included in the detection signal pattern. In Fig. 8A, the detection signals after weighting are shown in a thick line graph.

[0063] The weighting function is set so that the weight is greater for more effective positions. For example, in the case shown in FIG. 7, the weighting function is set so that the weight is smaller for positions closer to the heart. This is because detection signals collected near the heart may be affected by pulsation, and detection signals collected at positions farther from the heart have higher reliability. Also, for example, the weighting function is set so that the weight is greater for positions closer to the center of the ROI. This is because, for example, in the regions of interest R11 and R13, the central parts are less likely to overlap with bones and have higher reliability. The weighting function may be automatically set by the X-ray control function 121d based on past examinations, or may be manually set by the user.

[0064] Next, the X-ray control function 121d integrates the weighted detection signals for each element array. In the case shown in Fig. 8A, the X-ray control function 121d integrates the weighted detection signals for each of the three element arrays to calculate three integrated values. Furthermore, the X-ray control function 121d integrates the three element arrays. That is, as described in step S112 of Fig. 6, the X-ray control function 121d integrates each detection signal for each ROI to calculate an integrated value for each ROI.

[0065] Next, a case where there is a difference between the detection signal pattern and the standard signal pattern will be described with reference to FIG. 8B. FIG. 8B shows a case where there is a difference between the detection signal pattern of the upper element row among the three element rows selected for the region of interest R13 and the standard signal pattern. For example, the comparison function 121c can specify an element row having a difference between the detection signal pattern and the standard signal pattern by calculating the KL divergence between the detection signal pattern and the standard signal pattern and comparing it with a threshold value. In this case, as described in step S109 of FIG. 6, the X-ray control function 121d ignores the detection signal of the element row specified by the comparison function 121c as an abnormal element row. In other words, the X-ray control function 121d controls the X-ray based on the detection signal detected in the element rows other than the element row specified by the comparison function 121c.

[0066] Next, the X-ray control function 121d applies a weighting function to each detection signal included in the detection signal pattern. In the case shown in FIG. 8B, the X-ray control function 121d applies a weighting function to each of the two element arrays excluding the element array identified by the comparison function 121c. Next, the X-ray control function 121d integrates the weighted detection signals for each element array. In the case shown in FIG. 8B, the X-ray control function 121d integrates the weighted detection signals for each of the two element arrays to calculate two integrated values.

[0067] Also, the X-ray control function 121d corrects the detection signals of the remaining element arrays as described in step S111 of FIG. 6. That is, when calculating the integrated value for each ROI, the detection signals of three element arrays in the region of interest R13 are used in the case of FIG. 8A, whereas the detection signals of only two element arrays in the region of interest R13 are used in the case of FIG. 8B, so that the integrated value decreases to about "2 / 3". In order to compensate for such a decrease in the signal, the X-ray control function 121d corrects the detection signals of the remaining element arrays according to the number of element arrays that have been ignored. For example, in the case shown in FIG. 8B, the X-ray control function 121d integrates the two element arrays and multiplies the integrated value by "3 / 2". That is, the X-ray control function 121d corrects and integrates the detection signals to calculate an integrated value for each ROI as described in steps S111 and S112 of FIG. 6.

[0068] Although the region of interest R13 has been described in FIG. 8A and FIG. 8B, the X-ray control function 121d calculates the integrated value for each ROI for the regions of interest R11 and R12 in the same manner. As described in steps S113 to S115 of FIG. 6, after calculating the integrated value for each ROI, the X-ray control function 121d judges whether there is a difference between the ROIs, and if there is a difference, ignores the detection signal of the abnormal ROI and corrects the detection signal of the remaining ROI. For example, the X-ray control function 121d compares the integrated values ​​of the regions of interest R11, R12, and R13, and judges the presence or absence of an abnormal ROI. For example, if the integrated values ​​of the regions of interest R12 and R13 are approximately the same, and only the integrated value of the region of interest R11 is significantly different, the X-ray control function 121d judges the region of interest R11 as the abnormal ROI that caused the difference in the integrated values, and corrects the detection signals of the remaining regions of interest R12 and R13. For example, when the region of interest R11 is to be ignored as an abnormal ROI, the X-ray control function 121d integrates the two element rows and multiplies the integrated value by "3 / 2".

[0069] 8A and 8B, it is assumed that there is no abnormal ROI. In this case, the X-ray control function 121d integrates the three ROIs and compares them with the threshold. That is, as explained in steps S116 and S117 of FIG. 6, the X-ray control function 121d adds up all the ROI integrated values ​​and compares them with the threshold. Here, if the total exceeds the threshold, the X-ray control function 121d stops (ends) imaging.

[0070] On the other hand, as shown in FIG. 6, if the threshold is not exceeded, the acquisition function 121b again proceeds to step S107 to acquire a detection signal. The detection signal acquired by proceeding again to step S107 is used after being integrated with the detection signals acquired so far. For example, when proceeding again to step S107, the acquisition function 121b integrates the detection signal for each detection element to reacquire the detection signal pattern for each element row. That is, similar to the case shown in the lower diagram of FIG. 5B, the detection signal is repeatedly collected and integrated until the threshold is exceeded.

[0071] As described above, according to the first embodiment, the selection function 121a selects a plurality of element rows in which detection elements are arranged in a row from among the detection elements included in the X-ray detector 15. The acquisition function 121b acquires a detection signal pattern indicating a pattern of a detection signal for each element row. The comparison function 121c compares the detection signal pattern with a standard signal pattern for each element row. The X-ray control function 121d controls X-rays based on the comparison result by the comparison function 121c and the detection signals detected in the plurality of element rows. Therefore, the X-ray imaging control device 12 according to the first embodiment can improve the accuracy of X-ray control without using an AEC detector.

[0072] Specifically, when the detection signal in the X-ray detector 15 is used for AEC, it is difficult to use a number of detection elements equivalent to the ROI of the AEC detector for AEC from the viewpoint of the image quality of the X-ray image and the calculation load. Furthermore, when AEC is performed based on the detection results of a limited number of detection elements, the imaging time is affected by the position of the selected detection elements. In response to this, the X-ray imaging control device 12 can eliminate the influence of detection elements that are not appropriately positioned by constantly comparing the detection signal pattern with the standard signal pattern, and appropriately control the imaging time. In other words, the X-ray imaging control device 12 can improve the stability of AEC by cutting out abnormal detection signals in real time.

[0073] Moreover, it is preferable that the decision to continue or end imaging is repeatedly made in as short a period as possible. This makes it possible to control X-rays with high time precision and optimize the exposure dose of the subject P and the image quality of the X-ray image. Meanwhile, the X-ray imaging control device 12 can cut out abnormal detection signals without adding processes with a high calculation load. In other words, the X-ray imaging control device 12 can ensure time precision.

[0074] In particular, depending on the imaging method, the imaging time is extremely short, and even a slight difference in the imaging time can greatly affect the amount of radiation exposure and image quality. For example, when performing chest X-ray imaging of the lung field as the imaging site, the imaging time is about 10 msec, and X-ray control in msec units is required. In response to this, the X-ray imaging control device 12 can achieve high time accuracy and appropriately control the imaging time.

[0075] Furthermore, the X-ray imaging control device 12 realizes highly accurate AEC without using an AEC detector in addition to the X-ray diagnostic apparatus 1. That is, the X-ray imaging control device 12 can reduce the cost for realizing AEC.

[0076] Furthermore, the X-ray imaging control device 12 sets a region of interest at an arbitrary position on the detection plane of the X-ray detector 15. That is, the X-ray imaging control device 12 can optimize the region of interest for each imaging operation, taking into consideration the age, physique, etc. of the subject P. Therefore, the X-ray imaging control device 12 can further improve the accuracy of X-ray control, compared to a case where the position of the region of interest is fixed.

[0077] Alternatively, the X-ray imaging control device 12 can adjust the region of interest during imaging. For example, after imaging is started, the selection function 121a determines whether the ROI set in step S105 was appropriate based on the detection signal pattern first acquired in step S107, and corrects it if it is not appropriate. The selection function 121a also reselects an element row based on the corrected ROI. Then, when moving again from step S117 to step S107, the acquisition function 121b acquires a detection signal pattern for the element row based on the corrected ROI.

[0078] In addition, in Fig. 6, a series of processes from step S107 to step S117 are described as being looped until the threshold value is exceeded. That is, in Fig. 6, a detection signal pattern is compared with a standard signal pattern at each loop, and an abnormal element row is identified. Also, in Fig. 6, whether or not there is a difference between ROIs is determined at each loop, and an abnormal ROI is identified. However, the embodiment is not limited to this, and an abnormal element row or ROI may be identified only in the first loop.

[0079] Here, there are several possible causes of abnormal element rows and ROIs. For example, a medical device may be embedded in a position corresponding to region R131 in FIG. 8B, and the medical device may cause a difference between the detection signal pattern and the standard signal pattern. As another example, a malfunction of a detection element in the X-ray detector 15 at a position corresponding to region R131 may cause noise, resulting in a difference between the detection signal pattern and the standard signal pattern.

[0080] When an abnormal element array or ROI occurs due to a medical device embedded in the subject P, there is little need to determine whether the element array or ROI is abnormal each time a series of processes from step S107 to step S117 is looped. That is, it is appropriate to treat an element array or ROI once determined to be abnormal as an abnormal element array or ROI thereafter. By omitting the determination of an abnormal element array or ROI, the X-ray imaging control device 12 can reduce the amount of calculation per loop. Specifically, when the X-ray imaging control device 12 transitions from step S117 to step S107 once, the element array or ROI once determined to be abnormal may continue to be treated as abnormal, and the processes of steps S108, S109, S113, and S114 may be omitted.

[0081] As described above, it is preferable to judge whether to continue or end imaging in as short a period as possible. Here, the X-ray imaging control device 12 reduces the amount of calculation by treating an element array or ROI that has been judged to be abnormal once as an abnormal element array or ROI thereafter, and repeats the judgment of step S117 in a short period, thereby improving the time accuracy of X-ray control.

[0082] On the other hand, if an abnormal element row or ROI occurs due to noise, it is preferable to determine the abnormal element row or ROI every time a series of processes from step S107 to step S117 is looped. This is because it is assumed that even if an element row or ROI is once determined to be abnormal, it will not be determined to be abnormal thereafter. Then, by re-determining element rows and ROIs that were once determined to be abnormal, the X-ray imaging control device 12 can reduce element rows and ROIs that are ignored as abnormal, thereby improving the accuracy of X-ray control. In addition, the design can be simplified by unifying the processing contents between the first loop and the second and subsequent loops.

[0083] 6, all ROI integrated values ​​are summed up and compared with the threshold in step S116, but the embodiment is not limited to this.

[0084] For example, in step S116, the X-ray control function 121d sums up all the ROI integrated values, divides the sum by the number of ROIs, and then compares the sum with a threshold. That is, the X-ray control function 121d compares the average value of the ROI integrated values ​​with a threshold. In this case, the amount of calculation increases because a step of calculating the average value is added, but the correction process in step S115 can be omitted, so there is a possibility that the processing speed will increase.

[0085] Alternatively, step S116 may be omitted. In this case, the X-ray control function 121d compares each ROI with the threshold value to determine whether or not to end imaging. For example, the X-ray control function 121d compares the integrated value in the region of interest R11 with the threshold value, compares the integrated value in the region of interest R12 with the threshold value, and compares the integrated value in the region of interest R13 with the threshold value. Then, the X-ray control function 121d ends imaging when the integrated value in any ROI exceeds the threshold value, or when the integrated value in all ROIs exceeds the threshold value. When comparing each ROI with the threshold value, the amount of calculation increases in that multiple processes according to the number of ROIs need to be performed in parallel, but the summation process in step S116 can be omitted, which may speed up the processing.

[0086] 6, the detection signal is integrated for each ROI in step S112, but the embodiment is not limited to this.

[0087] For example, in step S112, the X-ray control function 121d integrates the detection signal for each ROI and further divides it by the number of detection elements. That is, the X-ray control function 121d calculates the average value of the detection signal for each ROI. In this case, the amount of calculation increases because a step of calculating the average value is added, but the correction process in step S111 can be omitted, so there is a possibility that the processing speed will increase.

[0088] Alternatively, step S112 may be omitted. For example, the X-ray control function 121d may compare the detection signal pattern with the threshold value as shown in the lower diagram of FIG. 5B instead of comparing the integrated value with the threshold value. That is, the X-ray control function 121d may compare each detection element with the threshold value. Then, the X-ray control function 121d ends the imaging when the threshold value is exceeded in the ROI of the detection element or when the threshold value is exceeded in all detection elements. When comparing each detection element with the threshold value, the amount of calculation increases in that multiple processes according to the number of detection elements must be performed in parallel, but the integration process of step S112 can be omitted, so that the processing speed may be increased.

[0089] In addition, in step S109 of FIG. 6, the description has been given assuming that the entire element array is ignored for the abnormal element array. However, the embodiment is not limited to this. For example, the comparison function 121c identifies a portion of an element array having a difference between a detection signal pattern and a standard signal pattern, which is the cause of the difference. For example, in the case shown in FIG. 8B, the comparison function 121c identifies an upper element array of the three element arrays selected for the region of interest R13 as an abnormal element array. Furthermore, the comparison function 121c identifies a portion of the identified element array that is included in the region R131 as the portion that is the cause of the difference between the detection signal pattern and the standard signal pattern. Then, the X-ray control function 121d controls the X-rays based on the detection signals detected in the portions of the three element arrays selected for the region of interest R13 excluding the portions identified by the comparison function 121c.

[0090] In the above-described embodiment, a region of interest is set on the detection surface of the X-ray detector 15, and a plurality of element rows are selected from among the detection elements included in the region of interest. However, the embodiment is not limited to this, and the step of setting the region of interest may be omitted. For example, the number and positions of element rows may be set in advance for the imaging region, and the selection function 121a may select a predetermined element row. Also, for example, the selection function 121a may select an element row in response to an input operation from a user, without setting a region of interest.

[0091] Furthermore, in the above embodiment, the detection signals in the element array selected by the selection function 121a are described as being used only for AEC, but they may also be used as image information at the same time.

[0092] For example, while X-rays are being irradiated, each detection element in the element row selected by the selection function 121a outputs a detection signal while retaining the accumulated charge. That is, the X-ray detector 15 performs non-destructive readout. The acquisition function 121b acquires a detection signal pattern indicating a pattern of the detection signal for each element row. The comparison function 121c compares the detection signal pattern with a standard signal pattern for each element row. The X-ray control function 121d controls X-rays based on the comparison result by the comparison function 121c and the detection signals detected in the multiple element rows. The image generation function 192 reads out detection signals from all detection elements of the X-ray detector 15, including the element row selected by the selection function 121a, and generates an X-ray image.

[0093] When performing non-destructive readout, even if a large number of detection elements are used for AEC, there is no effect on image quality. However, the calculation load for AEC increases and the time accuracy decreases, so there is a limit to the number of detection elements that can be used for AEC. In other words, the X-ray imaging control device 12 can improve the accuracy of X-ray control even when using an X-ray detector 15 that is capable of non-destructive readout.

[0094] In the above embodiment, the case where the imaging part is a lung field is described as an example, but the present invention can be applied to other imaging parts. For example, in the case of an imaging part or a cervical vertebra, the selection function 121a sets a region of interest R21 shown in FIG. 9 and selects multiple element rows from among the detection elements included in the region of interest R21. The acquisition function 121b acquires a detection signal pattern indicating a pattern of a detection signal for each element row. The comparison function 121c compares the detection signal pattern with a standard signal pattern for each element row. The X-ray control function 121d controls X-rays based on the comparison result by the comparison function 121c and the detection signals detected in the multiple element rows. Even in the case shown in FIG. 9, the X-ray control function 121d may apply a weighting function to the detection signals detected in the multiple element rows. For example, the weighting function is set so that the weight is larger toward the center of the ROI. This is because, for example, the peripheral part of the region of interest R21 is more likely to be out of the cervical vertebrae, and the reliability is higher toward the center.

[0095] 1, an apparatus for imaging a subject P in an upright position has been described as the X-ray diagnostic apparatus 1, but there is no particular limitation on the type of the X-ray diagnostic apparatus 1. For example, the X-ray diagnostic apparatus 1 may be an X-ray angiography apparatus further equipped with a C-arm that holds the X-ray tube 13 and the X-ray detector 15, or may be a mammography apparatus.

[0096] For example, when the X-ray diagnostic device 1 is a mammography device, it can perform imaging of the breast of the subject P. In this case, the selection function 121a sets a region of interest R31 shown in FIG. 10, and selects multiple element rows from among the detection elements included in the region of interest R31. The acquisition function 121b acquires a detection signal pattern indicating a pattern of a detection signal for each element row. The comparison function 121c compares the detection signal pattern with a standard signal pattern for each element row. The X-ray control function 121d controls X-rays based on the comparison result by the comparison function 121c and the detection signals detected in the multiple element rows. Even in the case shown in FIG. 10, the X-ray control function 121d may apply a weighting function to the detection signals detected in the multiple element rows. For example, the weighting function is set so that the weight is larger toward the center of the ROI and is larger on the chest wall side.

[0097] 7, 9, 10, etc. show element rows arranged in the horizontal direction, but the direction of the element rows is not particularly limited. That is, the selection function 121a selects a plurality of element rows in which detection elements are arranged in a row along an arbitrary direction from among the detection elements included in the X-ray detector 15.

[0098] In the above embodiment, the imaging conditions such as the X-ray dose and irradiation range have been described as being controlled by the control function 191, but these imaging conditions may also be controlled by the X-ray imaging control device 12. For example, the X-ray control function 121d controls the imaging time by switching X-rays on / off, and also controls the operation of the X-ray high voltage device 11, the X-ray aperture 14, etc., thereby controlling various imaging conditions such as the X-ray dose and irradiation range.

[0099] In the above embodiment, the generation and display of the X-ray image has been described as being performed by the processing circuitry 19, but the X-ray imaging control device 12 may perform these functions. For example, the processing circuitry 121 in the X-ray imaging control device 12 further includes a function equivalent to the image generation function 192, and generates an X-ray image based on detection signals output from each detection element of the X-ray detector 15. For example, the processing circuitry 121 in the X-ray imaging control device 12 further includes a function equivalent to the output function 193, and displays the X-ray image on the display 17.

[0100] 1, the X-ray imaging control device 12 is described as being included in the X-ray diagnostic apparatus 1, but the embodiment is not limited to this. For example, the X-ray imaging control device 12 may be a separate device that can be connected to the X-ray diagnostic apparatus 1.

[0101] The term "processor" used in the above description means a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). When the processor is, for example, a CPU, the processor realizes a function by reading and executing a program stored in a memory circuit. On the other hand, when the processor is, for example, an ASIC, instead of storing a program in a memory circuit, the function is directly incorporated as a logic circuit in the circuit of the processor. Note that each processor in the embodiment is not limited to being configured as a single circuit for each processor, but may be configured as one processor by combining multiple independent circuits to realize the function. Furthermore, multiple components in each figure may be integrated into one processor to realize the function.

[0102] 1, the single memory 18 is described as storing a program corresponding to each processing function of the processing circuit 19. In addition, in FIG. 2, the single memory 122 is described as storing a program corresponding to each processing function of the processing circuit 121. However, the embodiment is not limited to this. For example, a configuration may be adopted in which a plurality of memories 18 are distributed and the processing circuit 19 reads out the corresponding program from each memory 18. Similarly, a configuration may be adopted in which a plurality of memories 122 are distributed and the processing circuit 121 reads out the corresponding program from each memory 122. In addition, instead of storing the program in the memory 18 or the memory 122, the program may be directly built into the circuit of the processor. In this case, the processor realizes the function by reading and executing the program built into the circuit.

[0103] Each component of each device according to the above-mentioned embodiment is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or a part of them can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. Furthermore, each processing function performed by each device can be realized in whole or in any part by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware using wired logic.

[0104] The control method described in the above-mentioned embodiment can be realized by executing a prepared program on a computer such as a personal computer or a workstation. This program can be distributed via a network such as the Internet. This program can also be recorded on a non-transitory recording medium readable by a computer such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, or a DVD, and executed by being read from the recording medium by a computer.

[0105] According to at least one of the embodiments described above, the precision of X-ray control can be improved.

[0106] Although some embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0107] 1 X-ray diagnostic equipment 12 X-ray photography control device 121 Processing circuit 121a Selection function 121b Acquisition function 121c comparison function 121d X-ray control function 13 X-ray tube 15 X-ray detector 19 Processing circuit 191 Control Functions 192 Image generation function 193 Output Function

Claims

1. 1. An X-ray imaging control device for controlling X-ray imaging in an X-ray diagnostic apparatus including an X-ray generating unit for generating X-rays, an X-ray detecting unit in which detection elements for detecting the X-rays and outputting detection signals are arranged in a matrix, and an image generating unit for generating an X-ray image based on the detection signals, a selection unit that selects a plurality of element rows in which detection elements are arranged in a row from among detection elements included in the X-ray detection unit; an acquisition unit that acquires a detection signal pattern indicating a pattern of the detection signal for each of the element arrays; a comparison unit that compares the detection signal pattern with a standard signal pattern that is preset for the position of the element array for each of the element arrays; an X-ray control unit that controls the X-rays to control an imaging time based on a comparison result by the comparison unit and the detection signals detected in the plurality of element rows; An X-ray imaging control device comprising:

2. 2. The X-ray imaging control device according to claim 1, wherein the X-ray control unit applies a weighting function to the detection signals detected in the plurality of element arrays, and controls the X-rays based on a comparison result by the comparison unit and the detection signals after the weighting function has been applied.

3. the comparison unit identifies the element row having a difference between the detection signal pattern and the standard signal pattern, 3 . The X-ray imaging control device according to claim 1 , wherein the X-ray control unit controls the X-rays based on the detection signals detected in the element rows excluding the element row identified by the comparison unit.

4. 4. The X-ray imaging control device according to claim 3, wherein the X-ray control unit performs a correction process on the detection signals detected in the element rows excluding the element row identified by the comparison unit among the plurality of element rows, and controls the X-rays based on the detection signals after the correction process.

5. 5. The X-ray imaging control device according to claim 1, wherein the selection unit sets a region of interest on a detection surface of the X-ray detection unit, and selects a plurality of the element rows from among detection elements included in the region of interest.

6. The X-ray imaging control device according to claim 5 , wherein the selection unit sets the region of interest in consideration of past examination information of the subject.

7. The X-ray imaging control device according to claim 5 , wherein the selection unit sets a plurality of the regions of interest, and selects a plurality of the element arrays for each of the plurality of the regions of interest.

8. 8. The X-ray imaging control device according to claim 7, wherein the X-ray control unit calculates an integrated value by integrating the detection signals for each region of interest, compares the integrated values ​​between the regions of interest to determine whether or not there is a difference, and, if there is a difference, controls the X-rays based on the detection signals detected in the regions of interest excluding the region of interest that caused the difference.

9. 9. The X-ray imaging control device according to claim 8, wherein the X-ray control unit performs a correction process on the detection signals detected in the regions of interest excluding the region of interest that caused the difference in the integrated values ​​among the multiple regions of interest, and controls the X-rays based on the detection signals after the correction process.

10. 10. The X-ray imaging control device according to claim 1, wherein the X-ray control unit controls on / off switching of the X-rays.

Images