Data transfer method, image generation method, and data transfer apparatus

Abstract

To reduce the amount of data to be transferred in an X-ray CT apparatus.SOLUTION: A data transfer method according to an embodiment includes a collection step, a calculation step, and a transmission step. The collection step collects detection data of X-rays detected by a detector. The calculation step calculates a difference between the X-ray detection data and a reference curve. The transmission step transmits difference information representing at least the difference.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to a data transfer method, an image generation method, and a data transfer device. [Background technology]

[0002] In recent years, X-ray computed tomography (X-ray CT) devices using photon-counting detectors and X-ray CT devices capable of capturing high-resolution X-ray CT images, such as dual-energy CT, have been developed.

[0003] In such an X-ray CT apparatus, the amount of data that is transferred from the gantry to the computer becomes large, so there is a need to reduce the amount of data to be transferred. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-079443 Summary of the Invention [Problem to be solved by the invention]

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to reduce the amount of data to be transferred in an X-ray CT apparatus. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0006] A data transfer method according to an embodiment includes a collection step, a calculation step, and a transmission step. The collection step collects detection data of X-rays detected by a detector. The calculation step calculates a difference between the X-ray detection data and a reference curve. The transmission step transmits difference information representing at least the difference. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an X-ray computed tomography apparatus according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of the X-ray detector according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a functional configuration of a DAS according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a curve according to the first embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of the flow of imaging and data transfer processing executed by the X-ray CT apparatus according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the flow of image generation executed by the console device according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating the effect of reducing the amount of data to be transferred by the X-ray CT apparatus according to the first embodiment. [Figure 8] FIG. 8 is a diagram showing an example of a curve according to the second embodiment. [Figure 9] FIG. 9 is a diagram showing an example of a curve according to the third embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a curve and a characteristic energy band according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a data transfer method, an image generation method, and a data transfer device will be described in detail with reference to the drawings.

[0009] (First embodiment) 1 is a diagram showing an example of the configuration of an X-ray computed tomography (CT) imaging apparatus 1 (hereinafter referred to as X-ray CT apparatus 1) according to the first embodiment. The X-ray CT apparatus 1 of this embodiment is a photon-counting CT apparatus.

[0010] As shown in Fig. 1, the X-ray CT apparatus 1 includes a gantry 10, a bed 30, and a console 40. In this embodiment, the rotation axis of the rotating frame 13 in a non-tilted state or the longitudinal direction of the tabletop 33 of the bed 30 is defined as the Z-axis direction, the axial direction perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction, and the axial direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. For convenience of explanation, multiple gantry devices 10 are depicted in Fig. 1, but the actual configuration of the X-ray CT apparatus 1 includes only one gantry device 10.

[0011] The gantry 10 and the bed 30 operate based on a user's operation via the console 40 or an operation unit provided on the gantry 10 or the bed 30. The gantry 10, the bed 30, and the console 40 are connected to each other by wire or wirelessly so as to be able to communicate with each other.

[0012] The gantry device 10 is an apparatus having an imaging system that irradiates an object P with X-rays and collects projection data from detection data of the X-rays that have passed through the object P. More specifically, the gantry device 10 has an X-ray tube 11 (X-ray generation unit), a wedge 16, a collimator 17, an X-ray detector 12, an X-ray high voltage device 14, a DAS (Data Acquisition System) 18, a rotating frame 13, and a control device 15.

[0013] The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermions from a cathode (filament) toward an anode (target) through the application of high voltage and supply of filament current from the X-ray high voltage device 14. X-rays are generated when thermions collide with the target. X-rays generated at the tube focus in the X-ray tube 11 are shaped into a cone beam via, for example, a collimator 17 and irradiated onto the subject P. For example, the X-ray tube 11 may be a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermions.

[0014] The X-ray detector 12 detects the X-rays emitted from the X-ray tube 11 and passed through the subject P, and outputs an electrical signal corresponding to the X-ray dose to the DAS 18. The X-ray detector 12 is a photon counting X-ray detector. The X-ray detector 12 is an example of a detector in this embodiment.

[0015] The X-ray detector 12 has, for example, multiple detection element rows in which multiple detection elements are arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. Each of the multiple detection elements detects the amount of incident X-rays.

[0016] FIG. 2 is a diagram showing an example of the configuration of the X-ray detector 12 according to the first embodiment. As shown in FIG. 2, the X-ray detector 12 has detecting elements 120a-120n, each made of, for example, a cadmium telluride semiconductor (CdTe, CdZnTe, etc.), arranged in multiple channels (N channels) in the channel direction and multiple rows (M rows) in the slice direction (the body axis direction of the subject P). Hereinafter, when the individual detecting elements 120a-120n are not particularly distinguished from one another, they will be simply referred to as detecting elements 120. The X-ray detector 12 counts photons derived from X-rays by directly converting incident X-rays into photons using the detecting elements 120. The X-ray detector 12 also discriminates the energy values ​​of transmitted X-rays. Note that even if the X-ray detector 12 is made up of a scintillator, a light guide, and a photomultiplier tube, it is still applicable by counting photons.

[0017] There are various types of X-ray CT devices 1, such as a Rotate / Rotate-Type (third generation CT) in which the X-ray tube 11 and X-ray detector 12 rotate together around the subject P, and a Stationary / Rotate-Type (fourth generation CT) in which a large number of X-ray detection elements are fixed in a ring-shaped array and only the X-ray tube 11 rotates around the subject P, and any of these types can be applied to this embodiment.

[0018] Returning to FIG. 1 , the rotating frame 13 supports the X-ray tube 11 and the X-ray detector 12 rotatably about a rotation axis. Specifically, the rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 so that they face each other and rotates the X-ray tube 11 and the X-ray detector 12 using a control device 15, which will be described later. The rotating frame 13 is rotatably supported on a fixed frame made of a metal such as aluminum. The rotating frame 13 receives power from a drive mechanism of the control device 15 and rotates at a constant angular velocity about the rotation axis.

[0019] The rotating frame 13 supports not only the X-ray tube 11 and the X-ray detector 12, but also the X-ray high voltage generator 14 and the DAS 18. The rotating frame 13 is housed in a substantially cylindrical housing having an opening (bore) that forms the imaging space. The central axis of the opening coincides with the rotation axis of the rotating frame 13.

[0020] The X-ray high voltage device 14 includes a high voltage generator having electrical circuits such as a transformer and a rectifier, and having the function of generating a high voltage to be applied to the X-ray tube 11 and a filament current to be supplied to the X-ray tube 11, and an X-ray control device that controls the output voltage according to the X-rays irradiated by the X-ray tube 11. The high voltage generator may be of a transformer type or an inverter type. The X-ray high voltage device 14 may be provided on the rotating frame 13, or on the fixed frame (not shown) side of the gantry device 10.

[0021] The control device 15 includes a processing circuit having a central processing unit (CPU) and the like, and a drive mechanism for a motor, an actuator, and the like. The processing circuit includes, as hardware resources, a processor such as a CPU or a microprocessing unit (MPU) and a memory such as a read-only memory (ROM) or a random access memory (RAM). The control device 15 may also be implemented by a processor such as a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA)). When the processor is a CPU, for example, the processor realizes a function by reading and executing a program stored in memory. On the other hand, when the processor is an ASIC, instead of storing a program in memory, the function is directly incorporated into the processor circuit as a logic circuit. Each processor in this embodiment is not limited to being configured as a single circuit, but may be configured as a single processor by combining multiple independent circuits, or may be configured to realize the functions of a single processor by integrating multiple components.

[0022] The control device 15 also has a function of receiving input signals from the console device 40 or an input interface attached to the gantry 10 and controlling the operation of the gantry 10 and the bed 30. For example, the control device 15 receives input signals and controls the rotation of the rotating frame 13, the tilt of the gantry 10, and the operation of the bed 30 and the tabletop 33. Note that the control of tilting the gantry 10 may be realized by the control device 15 rotating the rotating frame 13 around an axis parallel to the X-axis direction based on inclination angle (tilt angle) information input via an input interface attached to the gantry 10. The control device 15 may be provided in the gantry 10 or in the console device 40.

[0023] The wedge 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. The wedge 16 is, for example, a wedge filter or a bow-tie filter, and is a filter made of processed aluminum so as to have a predetermined target angle and a predetermined thickness.

[0024] The collimator 17 is a lead plate or the like for constricting the X-rays transmitted through the wedge 16 to an X-ray irradiation range, and a slit is formed by combining a plurality of lead plates or the like.

[0025] The DAS 18 collects detection data related to the subject P. More specifically, the DAS 18 collects signals detected by the X-ray detector 12. The DAS 18 includes, for example, an amplifier, an A / D (analog / digital) converter, and a control circuit. The DAS 18 may further include other components. Under the control of the control device 15, the DAS 18 transmits (transfers) detection data (raw data) based on the X-ray detection results obtained from the X-ray detector 12 to the console device 40. The DAS 18 is an example of a data transfer device in this embodiment. The DAS 18 may be connected to the console device 40 directly so as to be able to communicate with it, or may be connected via the control device 15.

[0026] The control circuit of the DAS 18 includes, for example, a processor such as a CPU or MPU and memory such as a ROM or RAM as hardware resources. The control device 15 may also be implemented by a processor such as a GPU, an ASIC, or a programmable logic device. If the processor is a CPU, for example, the processor implements its functions by reading and executing a program stored in memory. On the other hand, if the processor is an ASIC, instead of storing the program in memory, the function is directly incorporated into the processor circuit as a logic circuit. Note that each processor in this embodiment is not limited to being configured as a single circuit, but may be configured as a single processor by combining multiple independent circuits to implement its function. Furthermore, multiple components may be integrated into a single processor to implement its function.

[0027] The bed device 30 is a device on which the subject P to be scanned is placed and moved, and includes a base 31, a bed driving device 32, a top 33, and a top support frame 34. The base 31 is a housing that supports the top support frame 34 so that it can move vertically. The bed driving device 32 is a motor or actuator that moves the top 33, on which the subject P is placed, in the longitudinal direction of the top 33. The bed driving device 32 moves the top 33 under the control of the console device 40 or the control device 15. The top 33, which is provided on the upper surface of the top support frame 34, is a plate on which the subject P is placed. Note that the bed driving device 32 may move the top support frame 34 in addition to the top 33 in the longitudinal direction of the top 33.

[0028] The console device 40 is a device that controls the gantry device 10 and generates CT image data based on the scan results obtained by the gantry device 10. The console device 40 has a memory 41 (storage unit), a display 42 (display unit), an input interface 43 (input unit), and a processing circuit 44 (processing unit). Data communication between the memory 41, the display 42, the input interface 43, and the processing circuit 44 is performed via a bus (BUS).

[0029] The memory 41 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit storage device that stores various types of information. The memory 41 stores, for example, projection data and reconstructed image data. In addition to an HDD or an SSD, the memory 41 may be a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a flash memory, or a drive device that reads and writes various types of information from and to a semiconductor memory element such as a RAM (Random Access Memory). The storage area of ​​the memory 41 may be located within the X-ray CT apparatus 1 or in an external storage device connected via a network. The memory 41 also stores a control program for the console device 40 according to this embodiment.

[0030] The display 42 displays various types of information. For example, the display 42 outputs medical images (CT images) generated by the processing circuitry 44, a GUI (Graphical User Interface) for receiving various operations from the operator, and the like. For example, the display 42 may be a liquid crystal display (LCD), a cathode ray tube (CRT), an organic electroluminescence display (OLED), a plasma display, or any other display, as appropriate. The display 42 may also be provided on the gantry device 10. The display 42 may also be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 40 main body.

[0031] The input interface 43 accepts various input operations from the operator, converts the accepted input operations into electrical signals, and outputs the electrical signals to the processing circuitry 44. For example, the input interface 43 accepts from the operator acquisition conditions for acquiring projection data, reconstruction conditions for reconstructing CT images, image processing conditions for generating post-processed images from CT images, etc. As the input interface 43, for example, a mouse, keyboard, trackball, switch, button, joystick, touchpad, touch panel display, etc. can be used as appropriate.

[0032] In this embodiment, the input interface 43 is not limited to one having physical operation components such as a mouse, keyboard, trackball, switch, button, joystick, touchpad, and touch panel display. For example, an example of the input interface 43 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 device and outputs the electrical signal to the processing circuit 44. The input interface 43 is also an example of an input unit. The input interface 43 may also be provided in the gantry device 10. The input interface 43 may also be configured as a tablet terminal or the like that is capable of wireless communication with the console device 40 main body.

[0033] The processing circuitry 44 controls the operation of the entire X-ray CT device 1 in response to electrical signals of input operations output from the input interface 43. For example, the processing circuitry 44 executes a control function 441, a regeneration function 442, a projection data generation function 443, and an image data generation function 444. The control function 441 is an example of a control unit. The regeneration function 442 is an example of a regeneration unit. The projection data generation function 443 is an example of a projection data generation unit. The image data generation function 444 is an example of an image data generation unit.

[0034] Here, for example, the processing functions executed by the control function 441, the regeneration function 442, the projection data generation function 443, and the image data generation function 444, which are components of the processing circuitry 44 shown in Fig. 1, are recorded in the memory 41 in the form of programs executable by a computer. The processing circuitry 44 is, for example, a processor, and realizes the function corresponding to each read program by reading and executing each program from the memory 41. In other words, the processing circuitry 44 in a state in which each program has been read has each function shown in the processing circuitry 44 in Fig. 1.

[0035] 1 illustrates a case where the control function 441, the regeneration function 442, the projection data generation function 443, and the image data generation function 444 are each realized by a single processing circuit 44, but the embodiment is not limited to this. For example, the processing circuit 44 may be configured by combining multiple independent processors, and each processor may realize each processing function by executing a respective program. Furthermore, each processing function of the processing circuit 44 may be realized by being appropriately distributed or integrated into a single or multiple processing circuits.

[0036] The control function 441 controls various processes based on input operations received from the operator via the input interface 43. Specifically, the control function 441 controls the CT scan performed by the gantry 10. For example, the control function 441 controls the operations of the X-ray high voltage device 14, the X-ray detector 12, the control device 15, the DAS 18, and the bed driving device 32, thereby controlling the collection process of detection data of X-rays that have passed through the subject P in the gantry 10. As an example, the control function 441 controls the collection process of projection data in a positioning scan that collects positioning images and in an imaging (main scan) that collects images used for diagnosis.

[0037] Furthermore, the control function 441 causes the display 42 to display images based on various image data stored in the memory 41. For example, the control function 441 causes the display 42 to display a positioning image or an X-ray CT image.

[0038] The regeneration function 442 regenerates the detection data based on the reference curve and difference information transferred from the DAS 18. In other words, the regeneration function 442 is a function that restores the detection data compressed by the DAS 18. The processing executed by the regeneration function 442 is an example of a regeneration step in this embodiment. In this embodiment, data before preprocessing is referred to as raw data (detection data), and data after preprocessing is referred to as projection data. Details of the curve and difference information will be described later.

[0039] The projection data generation function 443 generates projection data by performing correction processing on the detection data regenerated by the regeneration function 442. For example, the projection data generation function 443 performs preprocessing such as logarithmic conversion processing, offset correction processing, inter-channel sensitivity correction processing, and beam hardening correction on the regenerated detection data. The processing executed by the projection data generation function 443 is an example of a projection data generation step in this embodiment.

[0040] The image data generation function 444 performs reconstruction processing using, for example, a filtered back projection (FBP) method or an iterative reconstruction method on the projection data generated by the projection data generation function 443 to generate X-ray CT image data. The X-ray CT image data is an example of X-ray medical image data in this embodiment. The processing executed by the image data generation function 444 is an example of a medical image generation step in this embodiment.

[0041] Next, the functions of the DAS 18 in this embodiment will be described. Fig. 3 is a diagram showing an example of the functional configuration of the DAS 18 according to the first embodiment. As shown in Fig. 3, the DAS 18 in this embodiment includes a collection function 18a, a curve generation function 18b, a calculation function 18c, and a transmission function 18d. The collection function 18a is an example of a collection unit. The curve generation function 18b is an example of a generation unit. The calculation function 18c is an example of a calculation unit. The transmission function 18d is an example of a collection unit.

[0042] These functions may be stored in the memory (storage unit) of the DAS 18, for example, in the form of programs executable by a computer. In this case, the processor of the DAS 18 reads each program from the memory and executes it to realize the function corresponding to each read program. In other words, the processing circuit 44 in a state in which each program has been read will have the functions shown in Fig. 3. Note that the storage unit of the DAS 18 may also store various data generated by processing curves, etc., which will be described later.

[0043] 3 may be realized by a single processing circuit, or may be realized by a combination of multiple independent processors. Alternatively, the various processing functions of the DAS 18 shown in FIG. 3 may be realized by being appropriately distributed or integrated into a single or multiple processing circuits. Furthermore, the various processing functions of the DAS 18 may be realized by a hardware circuit.

[0044] The collection function 18a collects detection data (raw data) of X-rays detected by the X-ray detector 12. The process executed by the collection function 18a is an example of a collection step in this embodiment.

[0045] More specifically, the collection function 18a counts the number of X-ray photons incident on each detection element 120 by discriminating the individual charges output by each detection element 120 of the X-ray detector 12. The collection function 18a also measures the energy of the counted X-ray photons by performing arithmetic processing based on the magnitude of each charge.

[0046] As a specific example, the collection function 18a collects energy values ​​for each detection time, detection position (position of each detection element 120) and phase (tube phase) of the X-ray tube 11 at which photons originating from individual X-rays transmitted through the subject P are detected. The collection function 18a also calculates (collects) a value (count rate or count value) indicating how many times each detection element 120 of the X-ray detector 12 counts photons originating from X-rays per unit time for each energy value. The collection function 18a thereby generates raw data for multiple energy bands based on the collected results, i.e., the detection time at which photons were detected, the detection position of the detection element 120, the tube phase, the energy value, and the count value. The energy bands are intervals into which the X-ray spectrum is divided, and are also called energy bins.

[0047] In other words, the detection data in this embodiment is the counting results of photons originating from X-rays emitted from the X-ray tube 11 in each of a plurality of energy bands.

[0048] The curve generation function 18b generates a curve by linearly interpolating the number of photons in each of a plurality of reference energy bands among a plurality of energy bands. The curve is an example of a reference curve in this embodiment. The curve is, for example, a broken line or curved line graph representing a specified number of photons for each energy band. The processing executed by the curve generation function 18b is an example of a generation step in this embodiment.

[0049] FIG. 4 is a diagram showing an example of a curve 91 according to the first embodiment. FIG. 4 shows a graph of actual detection data 90 and a curve 91. The horizontal axis of the graph in FIG. 4 represents photon energy, and the vertical axis represents the number of photon counts. The curve generation function 18b divides the energy range into a plurality of energy bands, adopts some of the divided energy bands as reference energy bands, and generates a curve 91 that linearly connects the number of photon counts in the reference energy bands. For example, in the example shown in FIG. 4, the curve generation function 18b generates a curve 91 that linearly connects the number of photon counts in the reference energy bands E0, E2, E4, E6, E8, and E10.

[0050] Furthermore, among the multiple energy bands, energy bands other than the reference energy band are difference calculation target energy bands. In the example shown in Fig. 4, energy bands E1, E3, E5, E7, and E9 are difference calculation target energy bands. The difference calculation target energy bands are the targets of difference calculation processing by the calculation function 18c, which will be described later. In other words, the curve generation function 18b classifies the multiple energy bands into a reference energy band and a difference calculation target energy band, and generates a curve 91 based on the reference energy band.

[0051] 4, among the multiple energy bands obtained by dividing the energy region at predetermined values, the reference energy band and the difference calculation target energy band are set alternately, but the number and proportion of energy bands used to generate the curve 91 are not limited to this. For example, two or more difference calculation target energy bands may be set between the reference energy bands.

[0052] The curve generation function 18b generates a curve 91 for each detection element 120. Note that it is not necessary to generate one curve 91 for one detection element 120. For example, the curve generation function 18b may use one curve 91 based on detection data for one detection element 120 as the curve 91 for a detection element 120 adjacent to that one detection element 120.

[0053] The energy bands that are the units for calculating the curve 91 and the difference information described below may be within a predetermined range or may be variable. For example, the curve generation function 18b may change the energy bands in accordance with changes in the count values. For example, the curve generation function 18b may widen the energy bands in energy regions where the changes in the count values ​​are small, and narrow the energy bands in energy regions where the changes in the count values ​​are large.

[0054] 3, the calculation function 18c calculates the difference between the X-ray detection data 90 and a reference curve 91. The processing executed by the calculation function 18c is an example of a calculation step in this embodiment. More specifically, the calculation function 18c calculates, for each detection element 120, the difference between the curve 91 and the X-ray detection data 90 in a difference calculation target energy band among multiple energy bands. The difference between the curve 91 and the detection data 90 is the difference between the number of photons indicated by the curve 91 for each energy band and the number of photons in the detection data 90.

[0055] 4, the calculation function 18c calculates a difference D11 between the count number C3 of the detection data 90 in the energy band E1 and the count number C11 of the curve 91. Furthermore, for example, the calculation function 18c calculates a difference D12 between the count number C4 of the detection data 90 in the energy band E7 and the count number C12 of the curve 91. Similarly, the calculation function 18c calculates the differences between the X-ray detection data 90 and the reference curve 91 for the energy bands E3, E5, and E9.

[0056] Furthermore, for the energy bands E0, E2, E4, E6, E8, and E10 used to generate the curve 91, the difference between the X-ray detection data and the reference curve 91 is naturally 0. For this reason, the calculation function 18c may exclude the energy bands E0, E2, E4, E6, E8, and E10 from the calculation of the difference.

[0057] The transmitting function 18d transmits at least difference information representing the difference calculated by the calculating function 18c. The process executed by the transmitting function 18d is an example of a transmitting step in this embodiment. More specifically, the transmitting function 18d in this embodiment associates the curve 91 for each detecting element 120 with the difference information and transmits the curve 91 and the difference information to the console device 40.

[0058] The difference information is, for example, information in which identification information for identifying each detection element 120 is associated with the difference between the detection data 90 for each energy band and the curve 91. As described above, the differences for the energy bands E0, E2, E4, E6, E8, and E10 used to generate the curve 91 are 0. Therefore, the difference information may include the differences for the energy bands E1, E3, E5, E7, and E9 that were not used to generate the curve 91.

[0059] The transmission function 18d transmits the curve 91 for each detection element 120 as information in which the count numbers in the energy bands E0, E2, E4, E6, E8, and E10 that make up the curve 91 are associated with each other.

[0060] The data amount of the curve 91 and the difference information is smaller than the data amount of the detection data 90. Therefore, the curve 91 and the difference information are, in other words, data in which the detection data 90 is compressed.

[0061] The DAS 18 may have other functions in addition to the above-described functions. For example, the DAS 18 may have a function to perform other information compression on the curve 91 and the difference information. Known techniques can be used as the information compression method. Furthermore, some or all of the above-described functions of the DAS 18 may be executed by the control device 15.

[0062] Next, the flow of imaging and data transfer processing executed by the X-ray CT apparatus 1 in this embodiment configured as above will be described.

[0063] 5 is a flowchart showing an example of the flow of imaging and data transfer processing executed by the X-ray CT apparatus 1 according to the first embodiment. Note that this flowchart explains only the main processing of the imaging and data transfer processing, and does not include all processing. For example, in FIG. 5, explanations of the operations of the X-ray tube 11, wedge 16, collimator 17, X-ray high voltage device 14, rotating frame 13, control device 15, and bed driving device 32 are omitted.

[0064] First, when the control function 441 of the X-ray CT apparatus 1 receives an imaging start request from the operator via the input interface 43 (S1 "Yes"), it controls the X-ray high voltage device 14 to start irradiating X-rays from the X-ray tube 11 (S2). The X-ray detector 12 detects the X-rays irradiated from the X-ray tube 11 and passed through the subject P, and outputs an electrical signal corresponding to the X-ray dose to the DAS 18. Furthermore, when the control function 441 of the X-ray CT apparatus 1 has not received an imaging start request from the operator (S1 "No"), it waits until it receives an imaging start request.

[0065] Then, the collection function 18a of the DAS 18 starts calculating the count values ​​for each energy band of the X-ray photons incident on each detection element 120 of the X-ray detector 12 (S3).

[0066] The collection function 18a generates detection data 90 for a plurality of energy bands based on the collected results, i.e., the detection time when the photon was detected, the detection position of the detection element 120, the tube phase, the energy value, and the count value (S4).

[0067] Then, the curve generation function 18b of the DAS 18 linearly interpolates the number of photons for each energy band to generate a curve 91 (S5).

[0068] Then, the calculation function 18c calculates the difference between the X-ray detection data 90 and the curve 91 (S6).

[0069] Then, the transmission function 18d of the DAS 18 associates the curve 91 for each detecting element 120 with the difference information and transmits them to the console device 40 (S7). At this point, the processing of this flowchart ends. Note that, although the transmission function 18d transmits the curve 91 and the difference information simultaneously in FIG. 5, the transmission timing of the curve 91 and the difference information does not necessarily have to be simultaneous. For example, the transmission function 18d may transmit the curve 91 first and then transmit the difference information.

[0070] Next, a flow of image generation executed by the X-ray CT apparatus 1 in this embodiment configured as above will be described.

[0071] 6 is a diagram showing an example of the flow of image generation executed by the console device 40 according to the first embodiment. The processing shown in FIG. 6 is executed following the processing in FIG.

[0072] First, the regeneration function 442 of the console device 40 receives the curve 91 and difference information for each detecting element 120 transferred from the DAS 18 (S11). Then, the regeneration function 442 regenerates the detection data 90 (raw data) based on the curve 91 and the difference information (S12). For example, the regeneration function 442 can obtain the detection data 90 by calculating the number of counts based on the curve 91 and the difference for each energy band.

[0073] Next, the projection data generating function 443 of the console device 40 generates projection data by performing a correction process on the detection data 90 regenerated by the regeneration function 442 (S13).

[0074] Then, the image data generating function 444 of the console device 40 performs reconstruction processing using filtered back projection, iterative reconstruction, or the like on the projection data to generate X-ray CT image data (S14).

[0075] Then, the control function 441 of the console device 40 causes the generated X-ray CT image data to be displayed on the display 42 (S15). At this point, the processing of this flowchart ends.

[0076] In this way, according to the DAS18 of the X-ray CT device 1 of this embodiment, the difference between the X-ray detection data 90 detected by the X-ray detector 12 and the curve 91 is calculated, and differential information representing at least this difference is transmitted, thereby reducing the amount of data to be transferred between the gantry device 10 including the DAS18 and the console device 40.

[0077] More specifically, the DAS 18 of the X-ray CT apparatus 1 of this embodiment generates a curve 91 by linearly interpolating the number of photons for each energy band, and transmits the curve 91 in association with the difference information. As described above, the data amount of the curve 91 and the difference information is smaller than the data amount of the detection data 90. Therefore, the DAS 18 of the X-ray CT apparatus 1 of this embodiment can compress the detection data 90 to be transferred and then transfer it to the console device 40.

[0078] Here, a description will be given of the effect of reducing the amount of data to be transferred by the X-ray CT apparatus 1 of this embodiment. Fig. 7 is a diagram illustrating the effect of reducing the amount of data to be transferred by the X-ray CT apparatus 1 according to the first embodiment.

[0079] In the example shown in FIG. 7, if the DAS 18 transfers the detection data 90 as is without compressing it, the count numbers for each of the energy bands E0 to E10 for each detection element 120 will be transferred to the console device 40.

[0080] In contrast, transferring the curve 91 and difference information as in this embodiment reduces the amount of data to be transferred. For example, in energy band E1, the difference D11 is smaller than the count C3 of the detection data 90. Similarly, in energy band E7, the difference D12 is smaller than the count C4 of the detection data 90. Furthermore, because the curve 91 is represented by the counts of the energy bands E0, E2, E4, E6, E8, and E10 that make up the curve 91, the amount of data to be transferred does not increase due to the curve 91. Therefore, the data transfer method of this embodiment reduces the amount of data to be transferred.

[0081] Another comparative example involves a method in which a specific energy band is used as a reference and the difference in counts between adjacent energy bands is calculated and then transferred. In this method, for example, if the count C1 in energy band E0 is used as a reference, a difference D1 between the count C1 and the count C3 in energy band E1 is calculated for energy band E1. Similarly, a difference D2 between the count C3 and the count C2 in energy band E2 is calculated for energy band E2. According to the comparative method, the difference between adjacent energy bands is calculated for each energy band E1-E10 in this manner. Therefore, the console device 40 regenerates the detection data 90 based on the actual count C1 in the reference energy band E0 and the differences in the other energy bands E1-E10. In this method, the amount of data to be transferred increases when the variation in counts between adjacent energy bands is large. For example, in the example shown in FIG. 7, the difference D1 in the comparative example is larger than the difference D11 in this embodiment. According to the DAS 18 of the X-ray CT apparatus 1 of this embodiment, even if there is a large variation in the count number between adjacent energy bands, it is possible to stably achieve the effect of reducing the amount of data to be transferred.

[0082] Furthermore, the console device 40 of the X-ray CT apparatus 1 of this embodiment regenerates the detection data 90 based on the curve 91 and difference information transferred from the DAS 18, generates projection data by performing correction processing on the regenerated detection data 90, and generates X-ray medical image data by performing back projection processing on the projection data. Therefore, the console device 40 of the X-ray CT apparatus 1 of this embodiment can restore the compressed detection data 90, so that even if the amount of data to be transferred is reduced, X-ray medical image data can be generated without affecting image quality, etc.

[0083] (Second embodiment) In the first embodiment described above, the DAS 18 of the X-ray CT apparatus 1 generates the curve 91 by linear interpolation. In this second embodiment, the DAS 18 generates a reference curve by high-order interpolation.

[0084] The X-ray CT apparatus 1 of this embodiment has the same configuration as the first embodiment described in Fig. 1. The console device 40 has various processing functions (control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444) similar to those of the first embodiment described in Fig. 1. The control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444 of the console device 40 have the same functions as those of the first embodiment.

[0085] Furthermore, the DAS 18 has various processing functions (collection function 18a, curve generation function 18b, calculation function 18c, and transmission function 18d) similar to those of the first embodiment described with reference to FIG.

[0086] The collection function 18a, calculation function 18c, and transmission function 18d of the DAS 18 have the same functions as those in the first embodiment. Furthermore, the curve generation function 18b of this embodiment generates a curve by performing high-order interpolation on the number of photons in each of three or more consecutive energy bands. Note that a known method can be used for the high-order interpolation.

[0087] FIG. 8 is a diagram illustrating an example of a curve 92 according to the second embodiment. As illustrated in FIG. 8, the curve 92 according to this embodiment is generated by high-order interpolation, resulting in a smoother curve than the curve 91 generated by linear interpolation. Therefore, the overall difference between the curve 92 and the detection data 90 tends to be smaller. In the example illustrated in FIG. 8, the difference between the count C3 of the detection data 90 in the energy band E1 and the count C21 of the curve 92 is a difference D21. Furthermore, the difference between the count C4 of the detection data 90 in the energy band E7 and the count C22 of the curve 92 is a difference D22. The difference D21 in the energy band E1 is larger than the difference D11 in the first embodiment, but the difference D22 in the energy band E7 is smaller than the difference D12 in the first embodiment. Thus, although the reduction amounts vary among the individual energy bands, the method of this embodiment tends to result in a larger overall data reduction amount.

[0088] In this way, according to the DAS 18 of the X-ray CT device 1 of this embodiment, the number of photons in each of three or more consecutive energy bands is interpolated in a high order to generate a curve 92, the difference between the detection data 90 and the curve 92 is calculated, and the curve 92 and the difference information are associated with each other and transmitted, thereby achieving the effect of the first embodiment and further reducing the amount of data to be transferred.

[0089] (Third embodiment) In the first and second embodiments described above, the DAS 18 of the X-ray CT apparatus 1 generates the curves 91 and 92 based on the detection data 90 to be transferred. In this third embodiment, the DAS 18 generates a reference curve from detection data of a positioning scan collected in advance.

[0090] The X-ray CT apparatus 1 of this embodiment has the same configuration as the first embodiment described in Fig. 1. The console device 40 has various processing functions (control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444) similar to those of the first embodiment described in Fig. 1. The control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444 of the console device 40 have the same functions as those of the first embodiment.

[0091] Furthermore, the DAS 18 has various processing functions (collection function 18a, curve generation function 18b, calculation function 18c, and transmission function 18d) similar to those of the first embodiment described with reference to FIG.

[0092] The acquisition function 18a, calculation function 18c, and transmission function 18d of the DAS 18 have the same functions as those in the first embodiment. Furthermore, the curve generation function 18b of this embodiment generates a curve for calculating the difference of the main scan based on detection data of past X-rays irradiated onto the subject P before the X-rays irradiated in the main scan. The detection data of past X-rays is, for example, a positioning scan performed before the main scan.

[0093] 9 is a diagram showing an example of a curve 93 according to the third embodiment. Because the same subject P as in the main scan is irradiated with X-rays in the positioning scan, the curve generation function 18b can generate a curve 93 that is close to the detection data 90 in the main scan. For example, in the energy band E1, the detection data 90 and the curve 93 overlap, so the difference is approximately zero. Furthermore, the difference D32 between the count number C4 of the detection data 90 in the energy band E7 and the count number C32 of the curve 93 is also smaller than the difference D12 in the first embodiment and the difference D22 in the second embodiment. Therefore, the difference value for each energy band calculated by the calculation function 18c in this embodiment is generally smaller than those in the first and second embodiments.

[0094] In this embodiment, the curve 93 is not generated from the detection data 90, and therefore all of the plurality of energy bands E0 to E10 become the energy bands for which differences are to be calculated.

[0095] In this embodiment, the curve 93 may be transmitted from the DAS 18 to the console device 40 in advance before the main scan. That is, the transmission function 18d of the DAS 18 can transmit the curve 93 to the console device 40 before the main scan, and transmit difference information to the console device 40 after the main scan. Therefore, the DAS 18 of the X-ray CT apparatus 1 of this embodiment can reduce the amount of data transferred after the main scan. This contributes to reducing the time required for data transfer processing after the main scan, and the X-ray CT apparatus 1 of this embodiment can shorten the time from the main scan to the display of an X-ray image.

[0096] Alternatively, in this embodiment, the curve generation function 18b may be a function of the console device 40 rather than the DAS 18. When the console device 40 is equipped with the curve generation function 18b, for example, the curve generation function 18b generates a curve 93 based on the detection data of the positioning scan and transmits the generated curve 93 to the DAS 18. In this case, the calculation function 18c of the DAS 18 calculates the difference between the curve 93 received from the console device 40 and the detection data 90 of the main scan. Also, in this case, the transmission function 18d of the DAS 18 does not need to transmit the curve 93 to the console device 40, and only needs to transmit the difference information. In this case, the X-ray CT apparatus 1 of this embodiment can further reduce the amount of data to be transferred.

[0097] Alternatively, the curve 93 may be generated by an information processing device other than the X-ray CT apparatus 1. In this case, the console device 40 and the DAS 18 of the X-ray CT apparatus 1 may acquire the curve 93 from the other information processing device via a network or the like, for example.

[0098] (Fourth embodiment) In the above-described first to third embodiments, the DAS 18 of the X-ray CT apparatus 1 transfers the curves 91 to 93 and the difference information to the console device 40. In this fourth embodiment, the DAS 18 transfers actual detection data for a characteristic energy band that includes a singularity among a plurality of energy bands.

[0099] The X-ray CT apparatus 1 of this embodiment has the same configuration as the first embodiment described in Fig. 1. The console device 40 has various processing functions (control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444) similar to those of the first embodiment described in Fig. 1. The control function 441, regeneration function 442, projection data generation function 443, and image data generation function 444 of the console device 40 have the same functions as those of the first embodiment.

[0100] Furthermore, the DAS 18 has various processing functions (collection function 18a, curve generation function 18b, calculation function 18c, and transmission function 18d) similar to those of the first embodiment described with reference to FIG.

[0101] The collection function 18a, curve generation function 18b, and calculation function 18c of the DAS 18 have the same functions as those in the first embodiment. Note that the curve generation function 18b in this embodiment may have the same functions as those in the second or third embodiment.

[0102] The transmission function 18d of the present embodiment does not transmit difference information for a characteristic energy band that includes a singularity among a plurality of energy bands, but transmits detection data.

[0103] FIG. 10 is a diagram illustrating an example of a curve 91 and a characteristic energy band 80 according to the fourth embodiment. In the example illustrated in FIG. 10, a singular point 8, where the count number changes suddenly, exists in an energy band E9 of the detection data 901. The energy band E9 including the singular point 8 is referred to as a characteristic energy band 80. Generally, when such a singular point 8 exists, the difference between the curve 91 and the detection data 901 becomes large. For this reason, the transmission function 18d of this embodiment transmits the count number C40 of the detection data 901 to the console device 40 for the characteristic energy band 80, rather than difference information. Note that, although FIG. 10 illustrates one characteristic energy band 80 among the multiple energy bands E0 to E10, the number of characteristic energy bands 80 is not limited to this.

[0104] As a method for the transmission function 18d to identify the characteristic energy band 80, for example, a case in which the difference calculated by the calculation function 18c is larger than a specified threshold may be determined as a singular point 8. Alternatively, the transmission function 18d may identify a value in the detection data 901 that is outside the standard range of the count number for each detection element 120 and each energy band as the singular point 8. Information indicating the standard range of the count number for each detection element 120 and each energy band may be stored in advance in a storage unit of the DAS 18, for example.

[0105] The regeneration function 442 of the console device 40 of this embodiment regenerates detection data for the plurality of energy bands other than the characteristic energy band 80 by processing similar to that of the first embodiment. The regeneration function 442 also regenerates the entire detection data 901 by combining the regenerated detection data for the bands other than the characteristic energy band 80 with the detection data corresponding to the characteristic energy band 80.

[0106] In this way, according to the DAS 18 of the X-ray CT device 1 of this embodiment, by transferring detection data 901 for the characteristic energy band 80 containing the singularity 8, it is possible to reduce the amount of data to be transferred in accordance with the actual detection data 901.

[0107] (Variation 1) The method for generating the curves 91 to 93 is not limited to the methods exemplified in the first to fourth embodiments. For example, the curve generation function 18b of the DAS 18 may generate a curve that serves as a reference for difference calculation based on estimated detection data of X-rays obtained by a model that reproduces the human body structure through simulation. The model that reproduces the human body structure through simulation is, for example, a mathematical model that estimates, by calculation, the energy of photons derived from X-rays that pass through the subject P. According to this modification, it is possible to generate the curves in advance without performing an actual scan.

[0108] In this modification, since a curve is not generated from the detection data 90, all of the energy bands E0 to E10 become the energy bands for which differences are calculated.

[0109] Furthermore, in this modification, the curve may be transmitted from the DAS 18 to the console device 40 in advance before the actual scan. Alternatively, in this modification, the curve generation function 18b may be a function of the console device 40 rather than the DAS 18. In this case, the transmission function 18d of the DAS 18 does not need to transmit the curve to the console device 40, and only needs to transmit the difference information. Alternatively, the curve may be generated by an information processing device other than the X-ray CT apparatus 1. In this case, the console device 40 and DAS 18 of the X-ray CT apparatus 1 may acquire the curve from the other information processing device via a network, for example.

[0110] (Variation 2) Furthermore, the curve generating function 18b of the DAS 18 may generate a curve that serves as a reference for difference calculation based on detection data obtained by scanning a phantom. In this case, the curve can be used in common for multiple subjects P.

[0111] In this modification, similarly to the first modification, all of the multiple energy bands E0 to E10 are energy bands for which a difference is calculated. In addition, in this modification, the curve may be transmitted from the DAS 18 to the console device 40 in advance before the actual scan. Alternatively, in this modification, the curve generation function 18b may be a function of the console device 40 rather than the DAS 18. In this case, the transmission function 18d of the DAS 18 does not need to transmit the curve to the console device 40, and only needs to transmit the difference information. Alternatively, the curve may be generated by an information processing device other than the X-ray CT apparatus 1. In this case, the console device 40 and the DAS 18 of the X-ray CT apparatus 1 may acquire the curve from the other information processing device via a network, for example.

[0112] (Variation 3) Furthermore, the curve generation function 18b of the DAS 18 may generate a curve by estimating the number of photons counted for each energy band based on clinical information about the subject P. The clinical information is, for example, information about the height, weight, sex, etc. of the subject P. The clinical information may be acquired by the console device 40 or the DAS 18 from an electronic medical record system or the like, or may be manually input by the operator.

[0113] The clinical information makes it possible to identify the body type of the subject P. Since the detection data differs depending on the body type of the subject P, the curve generation function 18b generates a curve according to the body type, thereby making it possible to generate a curve that is less different from the detection data without using actual detection data.

[0114] For example, the curve generating function 18b may generate a plurality of curves in advance according to combinations of height, weight, and sex, and select a curve to be applied according to the medical information of the subject P to be scanned.

[0115] In this modification, similarly to the first modification, all of the multiple energy bands E0 to E10 are energy bands for which a difference is calculated. In addition, in this modification, the curve may be transmitted from the DAS 18 to the console device 40 in advance before the actual scan. Alternatively, in this modification, the curve generation function 18b may be a function of the console device 40 rather than the DAS 18. In this case, the transmission function 18d of the DAS 18 does not need to transmit the curve to the console device 40, and only needs to transmit the difference information. Alternatively, the curve may be generated by an information processing device other than the X-ray CT apparatus 1. In this case, the console device 40 and the DAS 18 of the X-ray CT apparatus 1 may acquire the curve from the other information processing device via a network, for example.

[0116] (Variation 4) The curve generation function 18b of the DAS 18 may generate a curve using an AI (Artificial Intelligence) model. The AI ​​model may be stored in the DAS 18 or the console device's storage unit, memory 41, or the like, or may be incorporated into the curve generation function 18b. The AI ​​model may be, for example, a model trained by deep learning or other machine learning. The AI ​​model may be, for example, a model trained on a curve obtained by a model that reproduces the human body structure through simulation, as described in Modification 1. Alternatively, the AI ​​model may be, for example, a model trained on associations between clinical information of multiple subjects scanned in the past and detection data of the multiple subjects. In this case, the curve generation function 18b may acquire a curve representing estimated detection data by inputting medical information of the subject P to be imaged into the trained model.

[0117] In this modification, similarly to the first modification, all of the multiple energy bands E0 to E10 are energy bands for which a difference is calculated. In addition, in this modification, the curve may be transmitted from the DAS 18 to the console device 40 in advance before the actual scan. Alternatively, in this modification, the curve generation function 18b may be a function of the console device 40 rather than the DAS 18. In this case, the transmission function 18d of the DAS 18 does not need to transmit the curve to the console device 40, and only needs to transmit the difference information. Alternatively, the curve may be generated by an information processing device other than the X-ray CT apparatus 1. In this case, the console device 40 and the DAS 18 of the X-ray CT apparatus 1 may acquire the curve from the other information processing device via a network, for example.

[0118] (Variation 5) Furthermore, in each of the above-described embodiments, the X-ray CT device 1 is a photon-counting CT device, but the X-ray CT device 1 is not limited to this. For example, the X-ray CT device 1 may be an energy-integrated CT device equipped with a two-layer detector.

[0119] In this modification, the X-ray detector 12 has two layers: a scintillator and a photosensor. These scintillators absorb X-rays in different energy bands. In this way, the two-layer detector detects X-rays in both the high-energy band and the low-energy band.

[0120] Generally, in a CT device equipped with a two-layer detector, the amount of data transferred from the DAS 18 to the console device 40 is large. By applying the data transfer method of each of the above-described embodiments to a CT device equipped with a two-layer detector, it is possible to achieve the effect of reducing the amount of data to be transferred.

[0121] (Variation 6) Furthermore, the X-ray CT device 1 may be a dual-energy CT device. A dual-energy CT device performs CT imaging using two types of X-rays with different tube voltages. In a dual-energy CT device, two sets of detection data are collected for one imaging target region, resulting in a large amount of data to be transferred. Therefore, by applying the data transfer method of each of the above-described embodiments to a dual-energy CT device, it is possible to achieve the effect of reducing the amount of data to be transferred.

[0122] The various data handled in this specification are typically digital data.

[0123] According to at least one of the embodiments described above, the amount of data to be transferred in the X-ray CT apparatus can be reduced.

[0124] Although several 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 within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0125] 1 X-ray CT device 8 Singularity 10 Mounting device 11 X-ray tube 12 X-ray detector 13 Rotating Frame 14 X-ray high voltage device 15 Control device 16 Wedge 17 Collimator 18 DAS 18a Collection Function 18b Curve generation function 18c Calculation Function 18d Transmission Function 30 Bed Device 31 Foundation 32 Bed drive unit 33 Top plate 34 Top plate support frame 40 Console device 41 memory 42 Display 43 Input Interface 44 Processing circuit 80 characteristic energy bands 90,901 detection data 91~93 Curve 120, 120a~120n Detector element 441 Control Functions 442 Regeneration function 443 Projection data generation function 444 Image data generation function P Subject

Claims

1. an acquisition step of acquiring detection data of X-rays detected by the detector; a calculation step of calculating a difference between the X-ray detection data and a reference curve; a transmitting step of transmitting difference information representing at least the difference; Data transfer methods, including:

2. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; generating the curve by linearly interpolating the number of photons in each of a plurality of reference energy bands among the plurality of energy bands; In the calculation step, the difference between the curve and the X-ray detection data in a difference calculation target energy band among the plurality of energy bands is calculated; In the transmitting step, the curve and the difference information are transmitted in association with each other. The data transfer method according to claim 1 .

3. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; generating the curve by performing high-order interpolation on the number of photons for each of three or more consecutive energy bands among the plurality of energy bands; In the transmitting step, the curve and the difference information are transmitted in association with each other. The data transfer method according to claim 1 .

4. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; generating the curve based on detection data of the past X-rays irradiated onto the subject prior to the X-rays; The data transfer method according to claim 1 .

5. generating the curve based on estimated detection data of the X-rays obtained by a model that reproduces a human body structure by simulation; The data transfer method according to claim 1 .

6. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; generating the curve by estimating the number of photons counted for each energy band based on clinical information about the subject; The data transfer method according to claim 1 .

7. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; In the transmitting step, for a characteristic energy band including a singular point among the plurality of energy bands, the difference information is not transmitted, and the detection data is transmitted. The data transfer method according to claim 1 .

8. the detection data represents count results of each of a plurality of energy bands of photons derived from the X-rays irradiated from the X-ray tube to the subject; the difference is a difference between the number of photons indicated by the curve for each difference calculation target energy band among the plurality of energy bands and the number of photons in the detection data, The difference information is information that associates the energy band with the difference. The data transfer method according to any one of claims 1 to 7.

9. a regeneration step of regenerating the detection data based on difference information representing a difference between the X-ray detection data and a reference curve, and the curve; a projection data generating step of generating projection data by performing a correction process on the regenerated detection data; a medical image generating step of generating X-ray medical image data by performing backprojection processing on the projection data; An image generation method comprising:

10. an acquisition unit that acquires detection data of X-rays detected by the detector; a calculation unit that calculates a difference between the X-ray detection data and a reference curve; a transmitter that transmits difference information representing at least the difference; A data transfer device comprising:

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