Data management device, photon-counting X-ray computed tomography device, data management method, and data management program

Abstract

To reduce the size of data in an unimportant energy range (bin) while securing the number of energy ranges (the number of bins) valuable for diagnosis.SOLUTION: A data management device according to embodiment comprises an acquisition unit, an importance update unit, and a data size processing unit, and manages data obtained by scanning with a photon-counting CT. The acquisition unit acquires the importance of each of three or more energy ranges concerning the data. In a case where information about the update reference of a plurality of importances is acquired, the importance update unit updates at least one of the importances on the basis of the update reference. The data size processing unit, on the basis of the updated importance, reduces the size of data about the energy range corresponding to the updated importance among the data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to a data management device, a photon-counting X-ray computed tomography device, a data management method, and a data management program. [Background technology]

[0002] Photon counting X-ray computed tomography (PCCT) devices measure the number of X-ray particles within a specific energy range (also called a bin), allowing them to perform analyses such as material fractionation based on differences in the CT values ​​of tissues within multiple energy (keV) ranges.

[0003] Increasing the number of bins corresponding to the number of energy ranges increases the amount of raw data used to reconstruct images. In this case, the storage area of ​​the server or other device that stores the raw data becomes constrained by the increased amount of raw data. Therefore, as the number of bins increases, the remaining storage period for the raw data may become shorter. The amount of raw data can be reduced by reducing the number of bins used when scanning a subject. However, this reduces the energy range that can be analyzed, potentially making it impossible to secure the number of bins required for diagnosis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-138796 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 size of data in unimportant energy ranges (bins) while ensuring the number of energy ranges (bin numbers) useful for diagnosis. 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 management device according to an embodiment includes an acquisition unit, an importance update unit, and a data size processing unit, and manages data obtained by a photon-counting CT scan. The acquisition unit acquires importance levels for each of three or more energy ranges related to the data. When the importance update unit acquires information related to update criteria for multiple importance levels, the importance update unit updates at least one of the multiple importance levels based on the update criteria. The data size processing unit reduces the size of data related to the energy range corresponding to the updated importance level based on the updated importance level. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram illustrating an example of a data management device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a PCCT device according to an embodiment. [Figure 3] FIG. 3 is a diagram showing an example in which the count number is set to zero by the data size processing function according to the embodiment. [Figure 4] FIG. 4 is a diagram showing an example of count numbers being integrated by a data size processing function according to the embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of a procedure for data size reduction processing according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of a procedure for data size reduction processing according to the embodiment. [Figure 7]FIG. 7 is a diagram showing an example of a scanogram and bin reduction information displayed on a display according to a third application example of the embodiment. [Figure 8] FIG. 8 is a diagram showing an example of a reconstructed image and a slider displayed on a display according to a fourth application example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a data management device, a photon-counting X-ray computed tomography device, a data management method, and a data management program will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a data management device 100. The data management device 100 is installed, for example, in various modalities capable of storing medical images or in a server device within a hospital. The memory 103 in the data management device 100 may be connected to a network as an external device separate from the data management device 100. In this case, the data management device 100 includes a processing circuit 105 and a communication interface 101. A photon-counting X-ray CT (Computed Tomography) device (hereinafter referred to as a PCCT device) is connected to the data management device 100. The data management device 100 manages data obtained by scanning with the PCCT device.

[0009] The data management device 100 includes a communication interface 101, a memory 103, and a processing circuit 105. As shown in FIG. 1 , in the data management device 100, the communication interface 101, the memory 103, and the processing circuit 105 are electrically connected via a bus. The data management device 100 is connected to a network via the communication interface 101. The network is communicably connected to, for example, a photon-counting X-ray CT device such as a PCCT device, an information processing system in a medical institution such as a hospital information system (hereinafter referred to as an HIS (Hospital Information System)) and a radiology information system (RIS (Radiology Information System)), an image reconstruction server, an image analysis server, a console terminal, and the like. In this case, the data management device 100 constitutes one of multiple components in a distributed system as an example of an embodiment.

[0010] 1 may have an input interface for inputting various user instructions, a display for displaying various information for setting update criteria for the importance, etc. The importance is, for example, a value indicating the degree of importance regarding the use of the count number of X-ray photons detected by a photon counting scan. Specifically, the importance is defined as the importance of a specific energy bin, which is an index indicating how important raw data for a specific energy range (specific energy bin) is to the user.

[0011] The various functions of the data management device 100 may be installed in a server of a medical image management system (hereinafter referred to as PACS (Picture Archiving and Communication Systems)), a server of an HIS, or a PCCT device.

[0012] For the sake of specificity, the following description will be given assuming that the data management device 100 is installed in a PCCT device. In this case, the PCCT device includes, for example, various functions in the processing circuit 105 of the data management device 100 and various units in the memory 103 of the data management device 100.

[0013] (Embodiment) FIG. 2 is a diagram illustrating an example of a PCCT apparatus 1 according to this embodiment. As shown in FIG. 2, the PCCT 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 axis perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction, and the axis perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. For ease of explanation, multiple gantry 10 are depicted in FIG. 2, but the actual configuration of the PCCT apparatus 1 includes only one gantry 10.

[0014] 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.

[0015] The gantry device 10 is an apparatus having an imaging system that irradiates an object P with X-rays and collects projection data used for reconstruction from detection data of the X-rays that have passed through the object P. The gantry device 10 performs photon-counting CT scans. The gantry device 10 has an X-ray tube 11 (X-ray generator), an X-ray detector 12, a rotating frame 13, an X-ray high-voltage device 14, a control device 19, a bow-tie filter 16, a collimator 17, and a DAS (Data Acquisition System) 18.

[0016] The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermoelectrons from a cathode (filament) toward an anode (target) through the application of high voltage from the X-ray high voltage device 14 and the supply of filament current. X-rays are generated when the thermoelectrons collide with the target. X-rays generated at the tube focus in the X-ray tube 11 pass through an X-ray radiation window in the X-ray tube 11, are shaped into a cone beam via a collimator 17, and are irradiated onto the subject P. The X-ray tube 11 may be, for example, a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

[0017] The X-ray detector 12 is, for example, a photon-counting X-ray detector. The photon-counting X-ray detector 12 counts photons of X-rays generated by the X-ray tube 11. Specifically, the photon-counting X-ray detector 12 detects the X-rays irradiated from the X-ray tube 11 and passing through the subject P in photon units, and outputs an electrical signal corresponding to the X-ray dose to the DAS 18. The photon-counting X-ray detector 12 has, for example, multiple detector element rows, in which multiple detector elements are arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. The photon-counting X-ray detector 12 has, for example, a structure in which multiple detector element rows are arranged in the slice direction (row direction). The photon-counting X-ray detector 12 is also called a main detector that detects X-rays that have passed through the subject P.

[0018] Specifically, the photon counting X-ray detector 12 is an indirect conversion detector having, for example, a grid, a scintillator array, and a photosensor array. The scintillator array has multiple scintillators. The scintillator has scintillator crystals that output light with a photon amount corresponding to the amount of incident X-rays. The grid is arranged on the X-ray incident side of the scintillator array and has an X-ray shielding plate that has the function of absorbing scattered X-rays. The photosensor array has multiple photosensor groups. The photosensor group has multiple photosensors. The photosensor has the function of amplifying light received from the scintillator and converting it into an electrical signal. The photosensor is, for example, an APD (Avalanche Photo-Diode) or a SiPM (Silicon Photo Multiplier). In other words, the photosensor receives light from the scintillator and outputs an electrical signal (pulse) corresponding to the incident X-ray photons. The electrical signal output by each detection element is also called a detection signal. The peak value (voltage) of this electrical signal (pulse) correlates with the energy value of the X-ray photon. Note that the photon counting X-ray detector 12 may be a direct conversion detector having a semiconductor element that converts incident X-rays into an electrical signal.

[0019] The rotating frame 13 is an annular frame that supports the X-ray tube 11 and the photon counting X-ray detector 12 so that they face each other, and rotates the X-ray tube 11 and the photon counting X-ray detector 12 using a control device 19, which will be described later. In addition to the X-ray tube 11 and the photon counting X-ray detector 12, the rotating frame 13 also supports an X-ray high voltage device 14 and a DAS 18.

[0020] The rotating frame 13 is rotatably supported by a non-rotating portion of the gantry 10 (e.g., a fixed frame, not shown in FIG. 2). The rotation mechanism includes, for example, a motor that generates a rotational driving force and a bearing that transmits the rotational driving force to the rotating frame 13 to rotate it. The motor is provided, for example, in the non-rotating portion. The bearing is physically connected to the rotating frame 13 and the motor. The rotating frame 13 rotates in response to the rotational force of the motor.

[0021] The rotating frame 13 and the non-rotating portion are each provided with a contactless or contactless communication circuit. This allows communication between the unit supported by the rotating frame 13 and the non-rotating portion or an external device of the gantry 10. For example, if optical communication is used as the contactless communication method, the detection data generated by the DAS 18 is transmitted by optical communication from a transmitter having a light-emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on the non-rotating portion of the gantry 10. The receiver then transfers the data from the non-rotating portion to the console device 40. Note that other communication methods may also be used, such as contactless data transmission methods such as capacitive coupling and radio wave methods, as well as contact data transmission methods using slip rings and electrode brushes. The rotating frame 13 is an example of a rotating portion.

[0022] 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.

[0023] The control device 19 includes a processing circuit having a CPU (Central Processing Unit) and other components, and a drive mechanism for motors, actuators, and other components. The processing circuit includes, as hardware resources, a processor such as a CPU or an MPU (Micro Processing Unit) and memories such as ROM (Read Only Memory) or RAM (Random Access Memory). The control device 19 may also be implemented using an ASIC, a Field Programmable Gate Array (FPGA), other Complex Programmable Logic Devices (CPLDs), or Simple Programmable Logic Devices (SPLDs). The control device 19 controls the X-ray high-voltage generator 14, the DAS 18, and other components in accordance with commands from the console device 40. The processor reads and executes programs stored in the memory to achieve the above control.

[0024] The control device 19 also has the 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 19 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. The control of tilting the gantry 10 may be realized by the control device 19 rotating the rotating frame 13 around an axis parallel to the X-axis direction based on inclination angle (tilt angle) information input through an input interface attached to the gantry 10. The control device 19 may be provided in the gantry 10 or in the console device 40. The control device 19 may be configured to directly incorporate a program into the circuitry of its processor instead of storing the program in its memory. In this case, the processor realizes the above control by reading and executing the program incorporated in the circuitry.

[0025] The bowtie filter 16 is disposed in front of the X-ray emission window of the X-ray tube 11. The bowtie filter 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the bowtie filter 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 bowtie filter 16 is a filter made of processed aluminum so as to have a predetermined target angle and a predetermined thickness.

[0026] Collimator 17 is a lead plate or the like for constricting the X-rays transmitted through bowtie filter 16 to X-ray irradiation range 113, and a slit is formed by combining a plurality of lead plates or the like.

[0027] The DAS 18 has a plurality of counting circuits. Each of the plurality of counting circuits has an amplifier that performs an amplification process on the electrical signals output from each detection element of the photon counting X-ray detector 12, and an A / D converter that converts the amplified electrical signals into digital signals, and generates detection data that is the result of counting using the detection signals of the photon counting X-ray detector 12. The detection data that is the result of counting is data in which the number of X-ray photons is assigned to each predetermined energy range (hereinafter referred to as energy bin). The energy bin is, for example, three or more energy ranges in which the count number of the detected X-ray photons is discriminated according to the energy of the X-ray photons.

[0028] For example, the DAS 18 counts photons (X-ray photons) derived from X-rays irradiated from the X-ray tube 11 and transmitted through the subject P, and discriminates the energy of the counted photons to obtain the counting process result. The detection data generated by the DAS 18 is transferred to the console device 40. The detection data is a set of data including the channel number of the detector pixel (detection element) that generated the detection data, the column number, the view number indicating the collected view (also called the projection angle), and a value indicating the count number of detected X-ray photons for each energy bin. The view number may be the order in which the view was collected (collection time), or a number (e.g., 1 to 1000) indicating the rotation angle of the X-ray tube 11. Each of the multiple counting circuits in the DAS 18 is realized, for example, by a circuit group equipped with circuit elements capable of generating detection data.

[0029] 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 19. 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.

[0030] 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).

[0031] 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 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 PCCT device 1 or in an external storage device connected via a network.

[0032] The memory 41 stores various programs according to this embodiment. For example, the memory 41 stores programs related to the execution of a system control function 441, a preprocessing function 442, a reconstruction processing function 443, an acquisition function 151, an importance update function 153, and a data size processing function 155, which are executed by the processing circuitry 44.

[0033] The memory 41 includes a raw data storage unit 131, an importance recording unit 133, and an importance update criterion recording unit 135. The raw data storage unit 131 stores raw data corresponding to a plurality of energy bins. Here, the raw data is, for example, detection data output by the DAS 18 or data (projection data) preprocessed by the preprocessing function 442. That is, the raw data collectively refers to detection data, which is data before preprocessing by the preprocessing function 442, and projection data, which is data after preprocessing by the preprocessing function 442. For example, the raw data storage unit 131 stores raw data corresponding to a plurality of preset energy bins. The plurality of energy bins are set in increments of, for example, 10 keV, in the range from the maximum energy to the minimum energy of X-ray photons.

[0034] The importance recording unit 133 associates importance with raw data corresponding to a channel number, a column number, a view number, and an energy bin and records the importance. In this case, the importance corresponds to additional information indicating an index of the importance of raw data corresponding to an energy bin. For example, the importance recording unit 133 associates a predetermined number (e.g., 10) as an initial value of importance with the raw data as additional information and records it. Furthermore, when the importance for a specific energy bin is updated by the importance update function 153 described below, the importance recording unit 133 associates the updated importance with the raw data related to the specific energy bin and records it.

[0035] The importance update criterion recording unit 135 records the importance update criterion. The importance update criterion is set to increase the importance value if the raw data corresponding to the energy bin is useful to the user, or to decrease the importance value if the raw data corresponding to the energy bin is not useful to the user. Specifically, the importance update criterion corresponds to decreasing the importance of an energy bin not used in analysis by 1, or increasing the importance of an energy bin used in analysis by 1.

[0036] Furthermore, the update criteria for the importance are set in advance according to, for example, the diagnostic purpose, the interpretation result, the analysis result in post-processing (hereinafter referred to as post-processing analysis), the scan condition, the reconstruction condition, the transfer of the reconstructed image, the transfer of the raw data, the creation time of the reconstructed image, the remaining capacity of the storage area (raw data storage unit 131) in which the raw data is saved, etc. The diagnostic purpose corresponds, for example, to the purpose of scanning the subject P, and corresponds to a character string of the diagnostic purpose written in an examination order for the subject P, etc. The interpretation result is, for example, the result of interpretation by the radiologist of a reconstructed image reconstructed based on raw data, and corresponds to a character string of findings or impressions written in an interpretation report for the subject P, etc. The analysis result corresponds, for example, to the results of various analyses of the reconstructed image reconstructed based on the raw data.

[0037] The update criteria for the importance of diagnostic objectives, interpretation results, and post-processing analysis are, for example, to increase the importance of energy bins useful for specific organs, the importance of energy bins useful for characterizing substances, and the importance of energy bins useful for material differentiation. Specifically, the update criteria for diagnostic objectives, interpretation results, and post-processing analysis are to increase the importance of energy bins useful for characterizing organs to be diagnosed, the importance of energy bins useful for material differentiation of substances (such as stones) identified by analysis results, and the importance of energy bins that have been used in analysis or may be used for organs to be diagnosed (i.e., are frequently used in analysis, etc.) in examination orders, interpretation reports, analysis items, etc.

[0038] The scan conditions are, for example, imaging conditions related to the execution of a scan on the subject P by the PCCT apparatus 1. The update criterion for the importance of the scan conditions is, for example, to increase the importance of energy bins that are useful for enhancing the contrast agent used in the scan on the subject P.

[0039] The reconstruction conditions are, for example, conditions related to the reconstructed image, and include designation of energy bins to be used in reconstruction and designation of energy bins to be excluded from reconstruction (i.e., not used in reconstruction) from the viewpoint of noise reduction during reconstruction. The energy bins excluded from reconstruction from the viewpoint of noise reduction correspond, for example, to a low-energy range. The criteria for updating the importance of the reconstruction conditions and the transfer of the reconstructed image are, for example, to increase or decrease the importance of the energy bins used in reconstruction. Increasing the importance corresponds to the possibility that raw data belonging to the energy bins used in reconstruction may be reused for reconstruction (hereinafter referred to as data reuse). Decreasing the importance corresponds to the fact that raw data belonging to the energy bins used in reconstruction is unnecessary for the user.

[0040] The increase or decrease in importance in the update criteria for the importance regarding the reconstruction conditions and the transfer of the reconstructed image is determined, for example, when reconstructing an image based on raw data or when transferring the reconstructed image, by the input result of a check box for selecting whether to increase or decrease the importance, which is displayed on the display 42. Specifically, when setting the reconstruction conditions or transferring the reconstructed image, if a check box regarding data reuse is checked by a user instruction via the input interface 43, an increase in the importance is set.

[0041] The update criteria for the importance of raw data transfer may be, for example, to increase or decrease the importance of the energy bin to which the transferred raw data belongs. Increasing the importance corresponds to the possibility that the transferred raw data will be reused. Decreasing the importance corresponds to the fact that the transferred raw data is unnecessary for the user. The increase or decrease in importance in the update criteria for the importance of raw data transfer is determined, for example, by the result of an input from a checkbox on the display 42 that selects whether to increase or decrease the importance when the raw data is transferred.

[0042] The update criterion for the importance level related to the creation time of the reconstructed image is, for example, to uniformly lower the importance levels of all energy bins related to raw data whose creation time of the reconstructed image is old.The update criterion for the importance level related to the remaining capacity of the raw data storage unit 131, which is the storage area where raw data is saved, is, for example, to uniformly lower the importance levels of all energy bins when the remaining capacity of the raw data storage unit 131 becomes low.

[0043] 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 user, and the like. For example, the display 42 displays various types of information for setting update criteria for importance. As the display 42, for example, a liquid crystal display (LCD), a cathode ray tube (CRT), an organic electroluminescence display (OLED), a plasma display, or any other display can be used 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. The display 42 corresponds to a display unit.

[0044] The input interface 43 accepts various input operations from the user, 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 user settings such as scan conditions for collecting projection data, reconstruction conditions for reconstructing CT images, image processing conditions for generating post-processed images from CT images, and energy range settings for saving raw data during photon counting scans. The input interface 43 also accepts input from the user regarding setting and changing the importance update criteria. The input interface 43 may be, for example, a mouse, keyboard, trackball, switch, button, joystick, touchpad, or touch panel display, as appropriate.

[0045] 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. The input interface 43 corresponds to the input unit.

[0046] The processing circuitry 44 controls the overall operation of the PCCT device 1 in response to electrical signals of input operations output from the input interface 43. For example, the processing circuitry 44 includes, as hardware resources, a processor such as a CPU, MPU, or GPU (Graphics Processing Unit) and memory such as ROM and RAM. The processing circuitry 44 executes a system control function 441, a preprocessing function 442, a reconstruction processing function 443, an acquisition function 151, an importance update function 153, and a data size processing function 155 using a processor that executes a program loaded in memory. The processing circuitry 44, which realizes the system control function 441, the preprocessing function 442, the reconstruction processing function 443, the acquisition function 151, the importance update function 153, and the data size processing function 155, respectively, corresponds to a system control unit, a preprocessing unit, a reconstruction processing unit, an acquisition unit, an importance update unit, and a data size processing unit. Note that each of the functions 441 to 443, 151, 153, and 155 is not limited to being realized by a single processing circuit. A processing circuit may be configured by combining a plurality of independent processors, and each processor may execute a program to realize each of the functions 441 to 443, 151, 153, and 155.

[0047] The system control function 441 controls each function of the processing circuitry 44 based on an input operation received from a user via the input interface 43. Specifically, the system control function 441 reads out a control program stored in the memory 41, loads it on the memory in the processing circuitry 44, and controls each unit of the PCCT apparatus 1 according to the loaded control program. For example, the processing circuitry 44 controls each function of the processing circuitry 44 based on an input operation received from a user via the input interface 43. For example, the system control function 441 performs a scan on the subject P using an energy bin arbitrarily set by the user via the input interface 43. Note that the energy bin setting may be performed separately by a bin setting function. Next, the system control function 441 stores the generated raw data in the raw data storage unit 131 in the memory 41.

[0048] The pre-processing function 442 generates data by performing pre-processing such as logarithmic conversion, offset correction, inter-channel sensitivity correction, and beam hardening correction on the detection data output from the DAS 18 .

[0049] The reconstruction processing function 443 performs reconstruction processing using, for example, filtered back projection (FBP) or iterative reconstruction on the projection data generated by the pre-processing function 442 to generate CT image data. The reconstruction processing function 443 stores the reconstructed CT image data in the memory 41. The projection data generated from the counting results obtained by photon-counting CT contains information on the energy of X-rays attenuated by passing through the subject P. Therefore, the reconstruction processing function 443 can reconstruct X-ray CT image data according to, for example, an energy bin selected in the reconstruction conditions. Furthermore, the reconstruction processing function 443 can reconstruct X-ray CT image data for each of, for example, a plurality of energy components.

[0050] Furthermore, the reconstruction processing function 443 can, for example, assign a color tone according to the energy component to each pixel of the X-ray CT image data of each energy component, and generate image data in which multiple X-ray CT image data color-coded according to the energy component are superimposed. Furthermore, the reconstruction processing function 443 can, for example, generate image data that enables identification of the substance by utilizing the K absorption edge (K edge) specific to the substance. Other image data generated by the reconstruction processing function 443 include monochromatic X-ray image data, density image data, effective atomic number image data, etc.

[0051] The acquisition function 151 acquires the importance of each of three or more energy ranges (energy bins) related to data obtained by a photon-counting CT scan. As described above, the importance indicates the degree of importance regarding the use of the count number of X-ray photons detected by a scan of the subject P. The multiple energy ranges correspond to multiple energy bins in which the count number of X-ray photons detected by a scan of the subject P is differentiated according to the energy of the X-ray photons. Specifically, the acquisition function 151 acquires the importance from the importance recording unit 133 in the memory 41. The acquisition function 151 also acquires information related to the criteria for updating the importance. This information includes, for example, the examination order, scan conditions, interpretation report, reconstruction conditions, analysis results for the reconstructed image, instructions for transferring the reconstructed image and / or raw data, the creation date of the reconstructed image, and the remaining capacity of the raw data storage unit 131. In the data management device 100, the acquisition function 151 acquires the importance from the importance recording unit 133 in the memory 103.

[0052] When the importance updating function 153 acquires information regarding update criteria for multiple importance levels, it updates at least one of the multiple importance levels based on the acquired update criteria. The timing of acquiring the importance levels corresponds to the timing when the acquisition function 151 acquires information regarding the update criteria. Note that the timing of acquiring information regarding the diagnostic purpose and scan conditions may be the point in time when the scan plan for the subject P is completed. The importance updating function 153 increases the importance level corresponding to an energy range related to the purpose of the scan for the subject P among the multiple energy bins. Furthermore, the importance updating function 153 increases the importance level corresponding to an energy range related to the scan conditions among the multiple energy bins.

[0053] For example, if the scan conditions and scan purpose are related to the liver of the subject P, the importance updating function 153 increases the importance of energy bins related to liver depiction and liver-related diseases (e.g., liver cancer). At this time, the correspondence between the energy bins for the target organ of the scan and the pathology of the target organ is stored in the importance update criteria recording unit 135 as, for example, a correspondence table (look-up table). The update of the importance related to the scan purpose and scan conditions corresponding to the diagnostic purpose is performed, for example, before the scan of the subject P.

[0054] The importance updating function 153 increases or decreases the importance of an energy bin associated with a reconstruction condition among the plurality of energy bins. The importance updating function 153 also increases or decreases the importance of an energy range among the plurality of energy bins that corresponds to the transfer of a reconstructed image. For example, if a check box related to data reuse is checked when setting the reconstruction conditions and transferring the reconstructed image, the importance updating function 153 increases the importance of the energy bin used to generate the reconstructed image. If the check box is not checked, the importance updating function 153 decreases the importance of the energy bin used to generate the reconstructed image. The importance updating function 153 also decreases the importance of energy bins not used to generate the reconstructed image.

[0055] The importance update function 153 increases or decreases the importance of an energy bin corresponding to the transfer of raw data among multiple energy bins. For example, if a check mark is entered in a check box related to data reuse when transferring raw data, the importance update function 153 increases the importance of the energy bin to which the transferred raw data belongs. On the other hand, if a check mark is not entered in the check box, the importance update function 153 decreases the importance of the energy bin to which the transferred raw data belongs. In addition, the importance update function 153 decreases the importance of energy bins not selected in the transfer of raw data.

[0056] The importance updating function 153 increases the importance of an energy bin related to an interpretation result and an analysis result among a plurality of energy bins. For example, the importance updating function 153 increases the importance of an energy bin related to a character string of a finding or impression in an interpretation report and an analysis result. Specifically, the importance updating function 153 increases the importance of an energy bin that is useful for grasping the characteristics of an organ to be diagnosed in the interpretation report and the analysis result, and the importance of an energy bin that is useful for material classification of a material (such as a stone) described in the analysis result and the interpretation report.

[0057] The importance update function 153 uniformly decreases the importance levels corresponding to the energy bins according to the time elapsed since the reconstructed image was created. The time elapsed can be set and changed as appropriate, for example, by a user's instruction via the input interface 43.

[0058] The importance updating function 153 uniformly reduces the multiple importance levels corresponding to the multiple energy bins in accordance with the remaining capacity of the storage area (raw data storage unit 131) where the raw data is stored. Specifically, the importance updating function 153 uniformly reduces the multiple importance levels corresponding to the multiple energy bins when the remaining capacity of the raw data storage unit 131 falls below a predetermined remaining capacity. The predetermined remaining capacity is, for example, 10% of the capacity of the entire storage area for the raw data, or a value such as 5 GB. The predetermined remaining capacity can be set and changed as appropriate, for example, by a user instruction via the input interface 43.

[0059] The increment and decrement of importance by the importance update function 153 is, for example, 1, but can be set and changed as appropriate by a user instruction via the input interface 43.

[0060] Based on the updated importance, the data size processing function 155 reduces the size of data related to the energy range corresponding to the updated importance among the data obtained by the photon-counting CT scan. Specifically, the data size processing function 155 reduces the size of raw data in energy bins (hereinafter referred to as low importance bins) related to importance levels below a threshold among multiple importance levels. More specifically, the data size processing function 155 sets the count number in the low importance bin to zero. Setting the count number to zero is equivalent to deleting the raw data related to the low importance bin. This reduces the volume of raw data.

[0061] FIG. 3 is a diagram showing an example of zeroing counts using the data size processing function 155. In FIG. 3, the counts versus energy (keV) are plotted like a spectrum, but in reality, they are plotted as a histogram with each of multiple energy bins as a width. As shown in FIG. 3, the energy range between two adjacent dotted vertical lines corresponds to an energy bin. In FIG. 3, the low-importance bins correspond to the two energy bins on the low-energy side and the two energy bins on the high-energy side in the distribution of counts across multiple energy bins. Therefore, raw data corresponding to the raw data deletion range shown in FIG. 3 is deleted. The raw data deletion shown in FIG. 3 is performed for all channel numbers, all column numbers, and all view numbers.

[0062] The data size processing function 155 may generate an approximation model that approximates the distribution of counts across multiple energy bins in response to acquisition of raw data. The approximation model is, for example, an approximation curve that approximates the distribution of counts across multiple energy bins using polynomial fitting with multiple parameters. In this case, the data size processing function 155 associates the approximation model, i.e., multiple parameters in the polynomial fitting, with the raw data and stores them in the raw data storage unit 131. If necessary, the data size processing function 155 restores the counts in the low importance bins (deleted data) from zero based on the approximation model in response to a user instruction via the input interface 43.

[0063] Furthermore, the data size processing function 155 may integrate the first data in the low importance bin with the second data in the energy bin adjacent to the low importance bin to reduce the size of the raw data in the low importance bin. Specifically, the data size processing function 155 integrates the first data and the second data by adding up the first count number corresponding to the first data and the second count number corresponding to the second data. At this time, the data size processing function 155 expands the energy bin corresponding to the integrated count number (hereinafter referred to as the integrated bin) to the combined energy range of the energy bin corresponding to the first data and the energy bin corresponding to the second data.

[0064] FIG. 4 is a diagram showing an example of count integration by the data size processing function 155. As shown in FIG. 4, the energy range between two adjacent dotted vertical lines corresponds to an energy bin. In FIG. 4, low importance bins correspond to two energy bins on the low energy side and two energy bins on the high energy side in the distribution of counts across multiple energy bins. Therefore, as shown in FIG. 4, raw data in a low importance bin is integrated with raw data adjacent to the low importance bin. At this time, the range of the two low importance bins on the low energy side and the range of the two low importance bins on the high energy side are each expanded as an integrated bin, as shown in FIG. 4. The integration of raw data shown in FIG. 4 is performed for all channel numbers, all column numbers, and all view numbers.

[0065] The data size processing function 155 may also transfer the raw data in the low importance bin to an external storage device, such as a storage device connected to a network for backing up the raw data.

[0066] The process of reducing data size (hereinafter referred to as data size reduction process) executed by the PCCT device 1 of this embodiment configured as above will be described with reference to Figures 5 and 6. Figures 5 and 6 are flowcharts showing an example of the procedure of the data size reduction process.

[0067] (Data size reduction process) (Step S501) The system control function 441 sets a plurality of energy bins. Then, the importance update function 153 associates a predetermined number (for example, 10) with each of the plurality of energy bins as an initial value of importance. The associated importance is recorded in the importance recording unit 133. Next, the acquisition function 151 acquires a plurality of importances for the plurality of energy bins from the importance recording unit 133.

[0068] (Step S502) The importance updating function 153 increases the importance based on the examination order, scan conditions, and the correspondence table. Specifically, the importance updating function 153 extracts character strings related to the scan target organ and the pathology related to the target organ from the examination order, for example, by a known character string extraction process. Next, the importance updating function 153 identifies an energy bin related to the character string from multiple energy bins by comparing the extracted character string (such as the name of the target organ or the pathology related to the target organ) with the correspondence table.

[0069] Furthermore, the importance updating function 153 identifies the type of contrast agent from the examination order for the contrast agent based on the scan conditions. The importance updating function 153 identifies an energy bin useful for contrast agent enhancement from multiple energy bins by comparing the identified type of contrast agent with a correspondence table of energy bins useful for contrast agent enhancement for each type of contrast agent. The importance updating function 153 increases the importance corresponding to the energy bin identified by the examination order and scan conditions. For convenience of explanation, in this step, the importance is described as being updated upon receiving an examination order and determining scan conditions, but the importance may be updated sequentially upon receiving an examination order and determining scan conditions.

[0070] (Step S503) The system control function 441 controls each unit in the PCCT device 1 according to the scan conditions and executes a scan on the subject P. The system control function 441 associates the raw data generated by the scan with the set multiple energy bins and stores them in the raw data storage unit 131. In the data management device 100, this step is unnecessary.

[0071] (Step S504) The importance update function 153 updates the importance in accordance with the reconstruction conditions for raw data, the transfer of a reconstructed image, and the transfer of raw data. For example, the importance update function 153 increases and updates the importance corresponding to an energy bin checked in accordance with a user instruction via the input interface 43 in check boxes related to multiple energy bins during the setting of reconstruction conditions, the transfer of a reconstructed image, and the transfer of raw data.

[0072] (Step S505) The data size processing function 155 compares each of the multiple importance levels with a threshold. The data size processing function 155 reduces the data size of the raw data in the low importance bin. The data size reduction may be, for example, processing such as deleting raw data as shown in FIG. 3 or integrating raw data as shown in FIG. 4. The method of reducing the size of raw data by the data size processing function 155 can be appropriately set and selected by a user instruction via the input interface 43. The data size processing function 155 may also transfer the raw data in the low importance bin to an external storage device.

[0073] The data size processing function 155 may generate an approximation model based on the distribution of count numbers across multiple energy bins before reducing the data size of the raw data. In this case, the data size processing function 155 associates the generated approximation model with the raw data and stores it in the raw data storage unit 131.

[0074] (Step S506) The importance updating function 153 updates the importance based on the interpretation results and / or analysis results. Specifically, the importance updating function 153 extracts character strings related to the target organ and the pathology related to the target organ from the interpretation report having the interpretation results and / or the analysis results, for example, by a known character string extraction process. Next, the importance updating function 153 identifies an energy bin related to the interpretation results and / or the analysis results from multiple energy bins by comparing the extracted character strings (such as the name of the target organ and the pathology related to the target organ) with a correspondence table. Note that the importance updating function 153 may also identify an energy bin related to the analysis results from multiple energy bins by comparing a character string in an analysis item in the analysis results with the correspondence table. Next, the importance updating function 153 increases the importance of the identified energy bin.

[0075] (Step S507) The processing in this step is similar to that in step S505, and therefore a description thereof will be omitted.

[0076] (Step S508) The importance update function 153 determines whether a predetermined time has passed since the reconstructed image was generated. If the predetermined time has passed since the reconstructed image was generated (Yes in step S508), the process proceeds to step S509. If the predetermined time has not passed since the reconstructed image was generated (No in step S508), the process proceeds to step S511.

[0077] (Step S509) The importance updating function 153 uniformly reduces the plurality of importance levels corresponding to the plurality of energy bins when a predetermined time has passed since the time when the reconstructed image was created.

[0078] (Step S510) The processing in this step is similar to that in step S505, and therefore a description thereof will be omitted.

[0079] (Step S511) The importance updating function 153 determines whether the remaining capacity of the raw data storage unit 131 is less than a predetermined remaining capacity. If the remaining capacity of the raw data storage unit 131 is less than the predetermined remaining capacity (Yes in step S511), the process proceeds to step S512. If the remaining capacity of the raw data storage unit 131 is equal to or greater than the predetermined remaining capacity (No in step S511), the process proceeds to step S514.

[0080] (Step S512) If the remaining capacity of the raw data storage unit 131 is less than a predetermined remaining capacity, the importance updating function 153 uniformly reduces the plurality of importance levels corresponding to the plurality of energy bins.

[0081] (Step S513) The processing in this step is similar to that in step S505, and therefore description thereof will be omitted. Note that the series of processing in steps S508 to S510 and the series of processing in steps S511 to S513 can be executed at any stage in the data size reduction processing.

[0082] (Step S514) If there is reconstructable raw data (Yes in step S514), the process proceeds to step S515. If there is no reconstructable raw data (No in step S514), the data size reduction process ends. Whether there is reconstructable raw data corresponds to whether the raw data is stored in the raw data storage unit 131.

[0083] (Step S515) If a user instruction to re-execute reconstruction is input via the input interface 43 (Yes in step S515), the processing from step S504 onwards is repeated. At this time, the data size processing function 155 may restore the reduced raw data using an approximation model. If a user instruction to re-execute reconstruction is not input (No in step S515), the processing from step S508 onwards is repeated.

[0084] The data management device 100 that manages raw data obtained by photon-counting CT scans according to the above-described embodiment and the PCCT device 1 equipped with the data management device 100 acquire the importance of each of three or more energy ranges related to the raw data, and when acquiring information related to update criteria for multiple importance levels, update at least one of the multiple importance levels based on the update criteria, and reduce the size of the raw data related to the energy range corresponding to the updated importance level based on the updated importance level.

[0085] Furthermore, the update criteria for the importance according to the embodiment are set so as to increase the importance value corresponding to an energy bin that is useful to the user and decrease the importance value corresponding to an energy range among the plurality of energy ranges that is useless to the user. The update criteria for the importance according to the embodiment are set based on at least one of, for example, the purpose of the scan, the scan conditions, the reconstruction conditions, the interpretation results, the analysis results, the transfer of the reconstructed image, the transfer of the raw data, the creation time of the reconstructed image, and the remaining capacity of the raw data storage unit 131.

[0086] The data management device 100 according to the embodiment and the PCCT device 1 equipped with the data management device 100 increase the importance corresponding to the energy bin related to at least one of the scan purpose, the scan conditions, the interpretation results, and the analysis results, increase or decrease the importance corresponding to the energy bin related to at least one of the reconstruction conditions, the transfer of raw data, and the transfer of the reconstructed image, and decrease the multiple importance levels according to at least one of the elapsed time since the creation of the reconstructed image and the remaining capacity of the raw data storage unit 131. Specifically, the data management device 100 and the PCCT device 1 according to the embodiment reduce the size of the raw data in low-importance bins.

[0087] For example, the data management device 100 and the PCCT device 1 according to the embodiment set the count number in the low importance bin to zero. Note that the data management device 100 and the PCCT device 1 according to the embodiment may restore the count number in the low importance bin from zero based on an approximation model.

[0088] Furthermore, the data management device 100 and the PCCT device 1 according to the embodiment may integrate the first data in a low importance bin with the second data in an energy bin adjacent to the low importance bin. For example, the data management device 100 and the PCCT device 1 according to the embodiment integrate the first data and the second data by adding up the first count number corresponding to the first data and the second count number corresponding to the second data.

[0089] As described above, the data management device 100 and PCCT device 1 according to this embodiment can update the preset importance level as needed according to the update criteria, and reduce the size of the raw data when the updated importance level falls below the threshold. As a result, the data management device 100 and PCCT device 1 according to this embodiment can ensure the storage of raw data related to energy bins that are likely to be useful to the user, and can reduce the size of raw data related to energy bins that are likely to be useless to the user. As a result, the data management device 100 and PCCT device 1 according to this embodiment can reduce the size of raw data, thereby increasing the remaining period of raw data required by the user.

[0090] For example, in the data management device 100 and PCCT device 1 according to this embodiment, important raw data is determined from the raw data corresponding to each of a plurality of energy bins, so the user can perform imaging (scanning) in the PCCT device 1 without constantly worrying about which energy bin storage setting is appropriate. In addition, the data management device 100 and PCCT device 1 according to this embodiment enable raw data of important energy bins to be stored for a longer period in the raw data storage unit 131 (such as the memory 103 or a raw data storage server), thereby improving usability.

[0091] (First application example) The difference from the embodiment is that when the remaining capacity in the raw data storage unit 131 is less than a predetermined remaining capacity, the threshold value to be compared with the importance is lowered.

[0092] The data size processing function 155 determines whether the remaining capacity of the storage area where raw data is saved is equal to or greater than a predetermined remaining capacity. If the remaining capacity of the storage area where raw data is saved is less than the predetermined remaining capacity, i.e., if the capacity of the area available for saving in the raw data saving unit 131 is less than the predetermined remaining capacity, the data size processing function 155 reduces the threshold. The value by which the threshold is reduced is set in advance, but can be changed as appropriate by a user instruction via the input interface 43. This determination and change of the threshold are performed, for example, prior to step S501 in the data size reduction process.

[0093] The data size processing function 155 reduces the size of the raw data in the low importance bin when the remaining capacity of the raw data storage area (raw data storage unit 131) is equal to or greater than a predetermined remaining capacity. This process is similar to steps S505, S507, S510, and S513 in the data size reduction process.

[0094] When the remaining capacity of the storage area in the raw data storage unit 131 is less than a predetermined remaining capacity, the data size processing function 155 reduces the size of raw data in an energy bin associated with an importance level among multiple importance levels that is below a value obtained by reducing the threshold. That is, when the remaining capacity of the storage area in the raw data storage unit 131 is less than the predetermined remaining capacity, the data size processing function 155 uses the reduced value of the threshold as a new threshold and executes steps S505, S507, S510, and S513 in the data size reduction process.

[0095] The data management device 100 according to the first application example of the embodiment described above and the PCCT device 1 equipped with the data management device 100 reduce the size of raw data in low-importance bins when the remaining capacity of the raw data storage area is equal to or greater than a predetermined remaining capacity, and reduce the size of raw data in energy bins associated with importance levels below a reduced threshold among multiple importance levels when the remaining capacity is less than the predetermined remaining capacity. Thus, the data management device 100 and the PCCT device 1 according to the first application example of the embodiment vary the threshold depending on the remaining capacity of the storage area in the raw data storage unit 131, enabling more efficient reduction in the size of raw data with low importance. Other effects are similar to those of the embodiment, and therefore will not be described further.

[0096] (Second application example) The difference from the embodiment is that when the remaining capacity in the raw data storage unit 131 exceeds a predetermined remaining capacity, the process of reducing the size of the raw data, that is, the data size reduction process, is stopped.

[0097] The data size processing function 155 determines whether the remaining capacity of the storage area (raw data storage unit 131) where raw data is stored exceeds a predetermined remaining capacity. This determination is performed, for example, prior to step S501 in the data size reduction process. If the remaining capacity of the storage area for raw data is equal to or less than the predetermined remaining capacity, the data size processing function 155 reduces the size of the raw data in the low importance bin. This process is similar to steps S505, S507, S510, and S513 in the data size reduction process.

[0098] The data size processing function 155 stops the process of reducing the size of raw data (data size reduction process) when the remaining capacity of the storage area in the raw data storage unit 131 exceeds a predetermined remaining capacity.

[0099] The data management device 100 according to the second application example of the embodiment described above and the PCCT device 1 equipped with the data management device 100 reduce the size of raw data in low-importance bins when the remaining capacity of the raw data storage area is equal to or less than a predetermined remaining capacity, and stop the data size reduction process when the remaining capacity exceeds the predetermined remaining capacity. In other words, the data management device 100 and PCCT device 1 according to the second application example can switch the data size reduction process ON / OFF depending on the remaining capacity of the storage area in the raw data storage unit 131. As a result, the data management device 100 and PCCT device 1 according to the second application example can more efficiently reduce the size of raw data depending on the remaining capacity and importance of the raw data. Other effects are similar to those of the embodiment, and therefore will not be described here.

[0100] (Third application example) In this application example, energy bins whose data sizes have been reduced by data size reduction processing according to the region of the subject P (e.g., head, chest, trunk (e.g., pelvis), legs, etc.) are displayed on the display 42. In the data size reduction processing in this application example, information on the energy bins reduced according to the region of the subject P (hereinafter referred to as bin reduction information) is stored in the memory 41 (or memory 103) in association with the region of the subject P. The bin reduction information is, for example, information on energy bins, integrated bins, and deleted energy bins (hereinafter referred to as deleted bins) according to the region of the subject P.

[0101] A display control function that controls the display on the display 42 is installed in the processing circuitry 15. The processing circuitry 15 that realizes the display control function corresponds to a display control unit. Note that each process realized by the display control function may be realized by the system control function 441.

[0102] Prior to executing the scan in step S503, the system control function 441 performs scanogram imaging on the subject P. As a result, the system control function 441 generates a scanogram image (also called a scanogram) of the subject P. Note that the generation of the scanogram image may be performed by the reconstruction processing function 443 or the like. The system control function 441 stores the scanogram image in the memory 41.

[0103] The acquisition function 151 acquires the scanogram generated by scanogram photography from the memory 41. When the PCCT device 1 and the data management device 100 are separate entities, the acquisition function 151 acquires the scanogram from the PCCT device 1. The acquisition function 151 stores the acquired scanogram in the memory 103.

[0104] The display control function reads out the bin reduction information and the scanogram from the memory 41 (or the memory 103). The display control function displays the bin reduction information and the scanogram on the display 42 according to the region of the subject P in the scanogram.

[0105] 7 is a diagram showing an example of the scanogram SG and the bin reduction information BRI displayed on the display 42. As shown in FIG. 7, the bin reduction information BRI shows how the data size has been reduced by performing a data size reduction process on the raw data acquired by the scan after scanography, reducing the head of the subject P to three n energy bins, the chest to five energy bins, and the pelvis to five energy bins (a cut method different from that for the chest). More specifically, as shown in FIG. 7, the bin reduction information BRI is raw data in stored energy bins / raw data in unstored energy bins, with the horizontal axis representing keV and the vertical axis representing the bed position. As shown in FIG. 7, the bin reduction information BRI visualizes the stored raw data according to the bins and the body part (bed position) of the subject P, and is displayed on the display 42.

[0106] In the graph showing the bin reduction information BRI, each energy bin is represented by a different hue (illustrated by different hatching in FIG. 7), and the lowest energy bin (hereinafter referred to as the lowest bin) and the highest energy bin (hereinafter referred to as the highest bin) among the energy bins related to the pelvis are displayed in black on the display 42. The black color of the lowest and highest bins among the energy bins related to the pelvis indicates that the raw data related to those two bins have been deleted (deleted bins).

[0107] According to this application example, when raw data of a specific energy bin is reduced, the user can easily grasp which energy bin the data has been deleted from. For example, as shown in Fig. 7, the user can easily grasp the energy bands for the energy bins and integrated bins from which raw data has been removed. As a result, according to this application example, the efficiency of examination of the subject P can be improved.

[0108] (Fourth application example) This application example differs from the third application example in that information in which raw data of a specific energy bin has been reduced is displayed together with a reconstructed image. When an energy bin to be used for reconstruction is specified by a user's instruction via the input interface 43, the reconstruction processing function 443 generates a reconstructed image using raw data related to the specified energy bin. At this time, the reconstruction processing function 443 associates the energy bin used for reconstruction with the reconstructed image and stores it in the memory 41.

[0109] The display control function displays energy bins (hereinafter referred to as reconstruction bins) related to the generation of a reconstruction image and energy bins including the energy bins, together with the reconstruction image, on the display 42. If there are any deleted bins among the multiple energy bins, the display control function displays the deleted bins and integrated bins as a slider (also referred to as a scroll bar). At this time, the display control function displays a slider cursor (also referred to as a knob) on the slider superimposed on the reconstruction bin. Furthermore, the display control function displays the deleted bins on the slider in black, for example, and controls the slider cursor so that it cannot be moved.

[0110] Furthermore, when the slider cursor of the slider is moved in response to a user instruction via the input interface 43, the reconstruction processing function 443 generates a reconstructed image using raw data in the integration bin or energy bin of the moved slider cursor. Then, the display control function displays the newly generated reconstructed image on the display 42 together with the slider to which the slider cursor has been moved.

[0111] Fig. 8 is a diagram showing an example of reconstructed images and sliders displayed on the display 42. In Fig. 8, a first reconstructed image (PCCT image) RI1 obtained by scanning the chest of the subject P with five energy bins is shown on the left, and a second reconstructed image (PCCT image) RI2 obtained by scanning with five energy bins in a different division from the left is shown on the right. Below each image area (which may be inside or outside the image area), sliders SL1 and SL2, which represent keV in the horizontal direction, are shown, and each energy bin is displayed color-coded with a different hue (different hatching in Fig. 8).

[0112] 8, for the slider SL1 relating to the reconstructed image RI1 on the left, the display control function displays a slider cursor SC1 superimposed on the reconstruction bin, which is the second energy bin from the left. The reconstructed image RI1 displayed on the display 42 indicates that it is an image obtained by reconstructing raw data in the second energy bin (reconstruction bin) from the left.

[0113] 8, the display control function displays the slider cursor SC2 superimposed on the reconstruction bin, which is the second energy bin from the left, in the slider SL2 related to the reconstructed image RI2 on the right side. The reconstructed image RI2 displayed on the display 42 indicates that it is a reconstructed image obtained by reconstructing raw data in the second energy bin from the left (reconstruction bin). Furthermore, in the slider SL2 related to the reconstructed image RI2 on the right side, the lowest bin and the highest bin are displayed in black on the display 42. The black color of the lowest bin and the highest bin in the slider SL2 related to the reconstructed image RI2 indicates that raw data related to these two bins has been deleted (deleted bins). If the lowest bin and the highest bin have been deleted, the display control function controls the movement of the slider cursor SC2 so that it cannot be moved to these deleted energy bins in the slider SL2.

[0114] According to this application example, when raw data of a specific energy bin is deleted as in application example 3, the user can easily understand which energy bin the data has been deleted from. For example, as shown in FIG. 8, the user can easily understand the energy bands for the energy bins and integration bins from which raw data has been deleted. Furthermore, according to this application example, reconstructed images corresponding to the movement of the slider cursors SC1 and SC2 can be reconstructed and displayed. This allows the user to easily understand which energy bin's raw data the displayed reconstructed image was reconstructed from, thereby improving the efficiency of examinations for the subject P.

[0115] When the technical idea of ​​the embodiment is realized by a data management method, the data management method for managing data obtained by photon-counting CT scans acquires the importance of each of three or more energy ranges related to the data, and when information regarding update criteria for the multiple importance levels is acquired, updates at least one of the multiple importance levels based on the update criteria, and reduces the size of the data related to the energy range corresponding to the updated importance level based on the updated importance level. The procedure and effects of the data size reduction process related to this data management method are the same as those described in the embodiment, so description will be omitted.

[0116] When the technical idea of ​​the embodiment is realized by a data management program, the data management program that enables a computer to manage data obtained by photon-counting CT scans causes the computer to obtain the importance of each of three or more energy ranges related to the data, and when information regarding update criteria for the multiple importance levels is obtained, update at least one of the multiple importance levels based on the update criteria, and reduce the size of the data related to the energy range corresponding to the updated importance level based on the updated importance level.

[0117] For example, the data size reduction process can be realized by installing a data management program in a computer in a modality such as a photon-counting X-ray CT scanner, a PACS server device, or a data storage server device, and expanding the program in memory. In this case, the program that can cause a computer to execute the method can also be stored and distributed on a storage medium such as a magnetic disk (such as a hard disk), an optical disk (such as a CD-ROM or DVD), or a semiconductor memory. The procedure and effect of the data size reduction process realized by the data management program are the same as those in the embodiment, so a description thereof will be omitted.

[0118] According to at least one of the embodiments described above, it is possible to reduce the size of data in unimportant energy ranges (bins) while ensuring the number of energy ranges (bin numbers) useful for diagnosis.

[0119] 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]

[0120] 1. Photon-counting X-ray CT device (PCCT device) 10 Mounting device 11 X-ray tube 12 X-ray detector 13 Rotating Frame 14 X-ray high voltage device 15 Processing circuit 16 Bowtie Filter 17 Collimator 18 DAS(Data Acquisition System) 19 Control device 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 100 Data management device 101 Communication Interface 103 memory 105 Processing circuit 131 Raw Data Storage Unit 133 Importance Recording Section 135 Importance Update Criteria Recording Section 151 Acquisition Function 153 Importance update function 155 Data size processing function 441 System Control Functions 442 Pre-processing function 443 Reconstruction Processing Function

Claims

1. A data management device that manages data obtained by photon counting CT scanning, an acquisition unit that acquires the importance of each of three or more energy ranges related to the data; an importance level update unit that, when information relating to update criteria for the plurality of importance levels is acquired, updates at least one of the plurality of importance levels based on the update criteria; a data size processing unit that reduces a size of data relating to an energy range corresponding to the updated importance of the data based on the updated importance; A data management device comprising:

2. the update criterion is set so as to increase an importance value corresponding to an energy range that is useful to the user among the plurality of energy ranges, and to decrease an importance value corresponding to an energy range that is useless to the user among the plurality of energy ranges. The data management device according to claim 1 .

3. The update criteria are set based on at least one of the purpose of the scan, the scan conditions related to the execution of the scan, the interpretation results of the reconstructed image reconstructed based on the data, the analysis results based on the reconstructed image, the reconstruction conditions related to the reconstructed image, the transfer of the reconstructed image, the transfer of the data, the creation time of the reconstructed image, and the remaining capacity of the storage area in which the data is saved.

3. The data management device according to claim 1.

4. The importance updating unit increasing importance of an energy range among the plurality of energy ranges that corresponds to an energy range relevant to a purpose of the scan; increasing the importance of an energy range associated with the scan condition among the plurality of energy ranges; increasing the importance of an energy range associated with the image interpretation result among the plurality of energy ranges; increasing the importance of an energy range associated with the analysis result among the plurality of energy ranges; increasing or decreasing the importance of an energy range associated with the reconstruction condition among the plurality of energy ranges; increasing or decreasing the importance of an energy range corresponding to the transfer of the data or the transfer of the reconstructed image among the plurality of energy ranges; reducing the plurality of importance levels corresponding to the plurality of energy ranges according to the time elapsed since the reconstructed image was created; reducing the plurality of importance levels corresponding to the plurality of energy ranges according to the remaining capacity; The data management device according to claim 3 .

5. the data size processing unit reduces a size of data in an energy range related to an importance level below a threshold among the plurality of importance levels; The data management device according to any one of claims 1 to 4.

6. the data size processing unit sets the count number in an energy range related to an importance level below a threshold value among the plurality of importance levels to zero. The data management device according to any one of claims 1 to 5.

7. the data size processing unit restores the count number in the energy range related to the importance below the threshold from zero based on an approximation model that approximates the distribution of the count number across the plurality of energy ranges; The data management device according to claim 6.

8. the data size processing unit integrates first data in an energy range related to an importance level below a threshold among the plurality of importance levels and second data in an energy range adjacent to the energy range related to the importance level below the threshold; The data management device according to any one of claims 1 to 5.

9. the data size processing unit sums a first count number corresponding to the first data and a second count number corresponding to the second data as a combination of the first data and the second data; The data management device according to claim 8 .

10. the data size processing unit transfers data in an energy range relating to an importance level below a threshold value among the plurality of importance levels to an external storage device; The data management device according to any one of claims 1 to 5.

11. The data size processing unit If the remaining capacity of the storage area for the data is equal to or greater than a predetermined remaining capacity, reducing the size of the data in an energy range related to an importance level below a threshold value among the plurality of importance levels; If the remaining capacity is less than the remaining capacity, reducing the size of data in an energy range related to an importance level that is lower than the reduced threshold value among the plurality of importance levels. The data management device according to any one of claims 1 to 10.

12. The data size processing unit If the remaining capacity of the storage area for the data is equal to or less than a predetermined remaining capacity, reducing the size of the data in an energy range related to an importance level below a threshold value among the plurality of importance levels; If the remaining capacity exceeds a predetermined remaining capacity, the process of reducing the size of the data is stopped. The data management device according to any one of claims 1 to 11.

13. A data management device according to any one of claims 1 to 12; a gantry device for performing the scan; A photon-counting X-ray computed tomography apparatus comprising:

14. A data management method for managing data obtained by photon counting CT scanning, comprising: obtaining a significance for each of three or more energy ranges for the data; When information regarding update criteria for the plurality of importance levels is acquired, at least one of the plurality of importance levels is updated based on the update criteria; reducing a size of the data relating to the energy range corresponding to the updated importance based on the updated importance; A data management method comprising:

15. A data management program that causes a computer to manage data obtained by photon counting CT scanning, The computer, obtaining a significance for each of three or more energy ranges for the data; When information regarding update criteria for the plurality of importance levels is acquired, at least one of the plurality of importance levels is updated based on the update criteria; reducing a size of the data relating to the energy range corresponding to the updated importance based on the updated importance; A data management program that makes this possible.

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