JP2024035539A - X-ray CT device, control method for X-ray CT device, and program - Google Patents

Abstract

An object of the present invention is to easily distinguish photographed contrast substances. An X-ray CT apparatus according to an embodiment includes a first acquisition section, a identification section, a scan control section, and a second acquisition section. The first acquisition unit acquires medical image data regarding a wide area medical image including an object of interest of the subject. The specifying unit specifies an irradiation area that includes a region of interest corresponding to the target of interest, is narrower than the wide area, and is a target for irradiating X-rays. The scan control unit causes the irradiation region to be irradiated with the X-rays and the irradiation region to be photographed repeatedly. The second acquisition unit acquires information regarding the flow state of the contrast material flowing into the object of interest. [Selection diagram] Figure 4

Description

Embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus, a method of controlling the X-ray CT apparatus, and a program.

When an X-ray CT (Computed Tomography) device photographs (scans) the organs of a subject (for example, a human body), a contrast agent (contrast substance) depending on the type of organ is injected into the subject. be. In conventional X-ray CT apparatuses, when two or more types of contrast substances are injected into a subject, it may be difficult to determine whether each contrast substance has been injected to an extent suitable for imaging an organ.

Japanese Patent Application Publication No. 2003-310597

The problem to be solved by the embodiments disclosed in this specification and the drawings is to make it easier to understand the injection state of a contrast substance. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems.

The X-ray CT apparatus of the embodiment includes a first acquisition section, a identification section, a scan control section, and a second acquisition section. The first acquisition unit acquires medical image data regarding a wide area medical image including an object of interest of the subject. The specifying unit specifies an irradiation area that includes a region of interest corresponding to the target of interest, is narrower than the wide area, and is a target for irradiating X-rays. The scan control unit causes the irradiation region to be irradiated with the X-rays and the irradiation region to be photographed repeatedly. The second acquisition unit acquires information regarding the flow state of the contrast material flowing into the object of interest.

FIG. 1 is a diagram showing an example of an X-ray CT apparatus 1 according to an embodiment. A diagram showing an example of the configuration of a DAS 16 according to an embodiment. FIG. 3 is a diagram illustrating an example of functional blocks of a reconfiguration function 53 according to the embodiment. FIG. 3 is a diagram showing an example of functional blocks of an image processing function 54 according to the embodiment. FIG. 3 is a diagram showing an example of the flow of testing a subject P using the X-ray CT apparatus 1. FIG. 1 is a flowchart showing an example of processing in the X-ray CT apparatus 1. The figure which shows an example of the graph explaining the visualized superimposed image 200 and data collection.

Hereinafter, an X-ray CT apparatus, a control method for the X-ray CT apparatus, and a program according to an embodiment will be described with reference to the drawings. The X-ray CT apparatus of the embodiment is a photon counting CT apparatus. A photon counting CT device uses a direct detector to discriminate substances through which X-rays have passed. The X-ray CT apparatus according to the embodiment takes CT images (hereinafter referred to as examination images) of organs of interest such as internal organs and blood vessels (hereinafter referred to as target organs), which are the targets of examinations in which contrast substances are injected. After an axial image is captured by simple CT scanning, a region of interest (ROI) is set in the region of the axial image that indicates the target organ. Furthermore, the X-ray CT device specifies a region including the ROI in a part of the axial image as the region to be updated, limits the X-ray irradiation region to the region to be updated, sequentially captures CT images using interior CT, and Measure the concentration of contrast material injected into the organ. Then, when the concentration of the contrast material in the target organ becomes equal to or higher than the threshold value, a scan is started to capture an examination image to be used for examining the target organ.

FIG. 1 is a diagram showing an example of an X-ray CT apparatus 1 according to an embodiment. The X-ray CT apparatus 1 includes, for example, a gantry device 10, a bed device 30, and a console device 40. In FIG. 1, for convenience of explanation, both a view of the gantry apparatus 10 as viewed from the Z-axis direction and a view as seen from the X-axis direction are shown, but in reality, there is only one gantry apparatus 10. In the embodiment, the rotation axis of the rotation frame 17 in a non-tilted state or the longitudinal direction of the top plate 33 of the bed device 30 is the Z-axis direction, and the axis perpendicular to the Z-axis direction and horizontal to the floor surface is the X-axis. The direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction.

The gantry device 10 includes, for example, an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high voltage device 14, an X-ray detector 15, and a data acquisition system (hereinafter referred to as DAS) 16. , a rotating frame 17, a control device 18, and a gantry driving device 19. The rotating frame 17 rotatably holds the X-ray tube 11 and the X-ray detector 15.

The X-ray tube 11 generates X-rays by irradiating thermoelectrons from a cathode (filament) toward an anode (target) by applying a high voltage from an X-ray high voltage device 14 . X-ray tube 11 includes a vacuum tube. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

The wedge 12 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11 to the subject P. The wedge 12 attenuates the X-rays that pass through it so that the distribution of the amount of X-rays irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. The wedge 12 is also called a wedge filter or a bow-tie filter. The wedge 12 is, for example, made of aluminum processed to have a predetermined target angle and a predetermined thickness.

The collimator 13 is a mechanism for narrowing down the irradiation range of the X-rays that have passed through the wedge 12. The collimator 13 narrows down the irradiation range of X-rays by forming a slit using a combination of a plurality of lead plates, for example. The collimator 13 is sometimes called an X-ray diaphragm. The narrowing range of the collimator 13 may be mechanically drivable.

The X-ray high voltage device 14 includes, for example, a high voltage generator 14A and an X-ray control device 14B. The high voltage generator 14A has an electric circuit including a transformer, a rectifier, etc., and generates a high voltage to be applied to the X-ray tube 11. The high voltage generator 14A may be one that boosts the voltage using the above-mentioned transformer, or may boost the voltage using an inverter.

The X-ray control device 14B includes, for example, a processing circuit including a processor such as a CPU (Central Processing Unit). The X-ray control device 14B receives an input signal from an input interface attached to the console device 40 or the gantry device 10, and controls the operation of the collimator 13 and the high voltage generator 14A. The X-ray control device 14B adjusts the X-ray irradiation range by controlling the collimator 13. The X-ray control device 14B controls the output voltage of the high voltage generator 14A according to the amount of X-rays to be generated in the X-ray tube 11, for example. The X-ray high voltage device 14 may be provided on the rotating frame 17 or may be provided on the fixed frame (not shown) side of the gantry device 10.

The X-ray detector 15 detects the intensity of X-rays generated by the X-ray tube 11 and incident upon the subject P. The X-ray detector 15 outputs to the DAS 16 an electrical signal (an optical signal or the like) corresponding to the intensity of the detected X-rays. The X-ray detector 15 has, for example, a plurality of X-ray detection element rows. Each of the plurality of X-ray detection element rows has a plurality of X-ray detection elements arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. The plurality of X-ray detection element rows are arranged in the slice direction (column direction, row direction).

The X-ray detector 15 is, for example, a direct detection type detector. As the X-ray detector 15, for example, a semiconductor diode having electrodes attached to both ends of the semiconductor can be used. X-ray photons incident on a semiconductor are converted into electron-hole pairs. The number of electron-hole pairs generated by the incidence of one X-ray photon depends on the energy of the incident X-ray photon. Electrons and holes are each attracted to a pair of electrodes formed at both ends of the semiconductor. The pair of electrodes generates an electric pulse having a peak value depending on the charge of the electron/hole pair. One electric pulse has a peak value that corresponds to the energy of the incident X-ray photon. X-ray detector 15 is an example of a photon counting detector.

The DAS 16 collects count data indicating the number of counts of X-ray photons detected by the X-ray detector 15 for a plurality of energy bins, for example, in accordance with a control signal from the control device 18. The count data regarding the plurality of energy bins corresponds to the energy spectrum regarding the incident X-rays to the X-ray detector 15, which is modified according to the response characteristics of the X-ray detector 15. DAS 16 outputs detection data based on digital signals to console device 40 . The detection data includes digital values of count data identified by the channel number of the generating X-ray detection element, the column number, and the view number indicating the view collected. The view number is a number that changes according to the rotation of the rotating frame 17, and is a number that is incremented according to the rotation of the rotating frame 17, for example. Therefore, the view number is information indicating the rotation angle of the X-ray tube 11. The view period is a period that falls between the rotation angle corresponding to a certain view number and the rotation angle corresponding to the next view number. The DAS 16 may detect the switching of views using a timing signal input from the control device 18, an internal timer, or a signal obtained from a sensor (not shown). . When performing a full scan and the X-ray tube 11 is continuously emitting X-rays, the DAS 16 collects a group of detection data for the entire circumference (360 degrees). When performing a half scan and the X-ray tube 11 is continuously emitting X-rays, the DAS 16 collects detection data for half the circumference (180 degrees).

FIG. 2 is a diagram showing an example of the configuration of the DAS 16 according to the embodiment. The DAS 16 includes readout channels corresponding to the number of X-ray detection elements. These multiple readout channels are implemented in parallel on an integrated circuit such as an Application Specific Integrated Circuit (ASIC). FIG. 2 shows only the configuration of the DAS 16-1 for one read channel.

The DAS 16-1 includes a preamplifier circuit 61, a waveform shaping circuit 63, a plurality of pulse height discrimination circuits 65, a plurality of counting circuits 67, and an output circuit 69. The preamplifier circuit 61 amplifies the detected electrical signal DS (current signal) from the connected X-ray detection element. For example, the preamplifier circuit 61 converts a current signal from a connected X-ray detection element into a voltage signal having a voltage value (peak value) proportional to the amount of charge of the current signal. A waveform shaping circuit 63 is connected to the preamplifier circuit 61 . The waveform shaping circuit 63 shapes the waveform of the voltage signal from the preamplifier circuit 61. For example, the waveform shaping circuit 63 reduces the pulse width of the voltage signal from the preamplifier circuit 61.

A plurality of counting channels corresponding to the number of energy bands (energy bins) are connected to the waveform shaping circuit 63. When n energy bins are set, the waveform shaping circuit 63 is provided with n counting channels. Each counting channel has a pulse height discrimination circuit 65-n and a counting circuit 67-n.

Each of the pulse height discrimination circuits 65-n discriminates the energy of the X-ray photon (X-ray photon) detected by the X-ray detection element, which is the peak value of the voltage signal from the waveform shaping circuit 63. For example, the pulse height discrimination circuit 65-n includes a comparison circuit 653-n. A voltage signal from the waveform shaping circuit 63 is input to one input terminal of each of the comparison circuits 653-n. Reference signals TH (reference voltage values) corresponding to different threshold values are supplied from the control device 18 to the other input terminal of each of the comparison circuits 653-n. For example, the comparison circuit 653-1 for the energy bin bin1 is supplied with the reference signal TH-1, the comparison circuit 653-2 for the energy bin bin2 is supplied with the reference signal TH-2, and the comparison circuit 653-2 for the energy bin bin2 is supplied with the reference signal TH-2. A reference signal TH-n is supplied to the comparison circuit 653-n for binn. Each of the reference signals TH has an upper limit reference value and a lower limit reference value. Each of the comparison circuits 653-n outputs an electric pulse signal when the voltage signal from the waveform shaping circuit 63 has a peak value corresponding to the energy bin corresponding to each of the reference signals TH. For example, if the peak value of the voltage signal from the waveform shaping circuit 63 is the peak value corresponding to energy bin bin1 (if it is between reference signals TH-1 and TH-2), Outputs electrical pulse signals. On the other hand, the comparison circuit 653-1 for the energy bin bin1 does not output an electric pulse signal if the peak value of the voltage signal from the waveform shaping circuit 63 is not the peak value corresponding to the energy bin bin1. Further, for example, when the peak value of the voltage signal from the waveform shaping circuit 63 is the peak value corresponding to the energy bin bin2 (when it is between the reference signals TH-2 and TH-3), the comparison circuit 653-2 ), outputs an electrical pulse signal.

The counting circuit 67-n counts the electric pulse signals from the pulse height discrimination circuit 65-n at a readout period that matches the view switching period. For example, the trigger signal TS is supplied from the control device 18 to the counting circuit 67-n at the switching timing of each view. In response to the supply of the trigger signal TS, the counting circuit 67-n adds 1 to the count stored in the internal memory every time an electric pulse signal is input from the pulse height discrimination circuit 65-n. When the next trigger signal is supplied, the counting circuit 67-n reads the count data (ie, count data) stored in the internal memory and supplies it to the output circuit 69. Further, the counting circuit 67-n resets the count stored in the internal memory to an initial value every time the trigger signal TS is supplied. In this way, the counting circuit 67-n counts the count for each view.

The output circuit 69 is connected to counting circuits 67-n for a plurality of readout channels mounted on the X-ray detector 15. For each of the plurality of energy bins, the output circuit 69 integrates the count data from the counting circuit 67-n for the plurality of readout channels to generate count data for the plurality of readout channels for each view. The count data of each energy bin is a set of count data defined by a channel, a segment (column), and an energy bin. The count data of each energy bin is transmitted to the console device 40 in units of views. The count data for each view is called a count data set CS.

The rotating frame 17 is an annular member that supports the X-ray tube 11, the wedge 12, the collimator 13, and the X-ray detector 15 so as to face each other. The rotating frame 17 is rotatably supported by a fixed frame around the subject P introduced therein. The rotating frame 17 further supports the DAS 16. The detection data outputted by the DAS 16 is transmitted via optical communication from a transmitter having a light emitting diode (LED) provided in the rotating frame 17 to a photodiode provided in a non-rotating portion (for example, a fixed frame) of the gantry device 10. It is transmitted to the receiver and transferred by the receiver to the console device 40. Note that the method for transmitting detection data from the rotating frame 17 to the non-rotating portion is not limited to the method using optical communication described above, and any contactless transmission method may be employed. The rotating frame 17 is not limited to an annular member, but may be an arm-like member as long as it can support and rotate the X-ray tube 11 and the like.

The X-ray CT apparatus 1 is, for example, a Rotate/Rotate-Type X-ray CT apparatus (a third generation CT), but is not limited to this, and is not limited to Stationary/Rotate-Type, in which a plurality of X-ray detection elements arranged in an annular shape are fixed to a fixed frame, and the X-ray tube 11 rotates around the subject P. It may also be an X-ray CT device (4th generation CT).

The control device 18 includes, for example, a processing circuit including a processor such as a CPU. The control device 18 receives input signals from an input interface attached to the console device 40 or the gantry device 10 and controls the operations of the gantry device 10, the bed device 30, and the DAS 16. For example, the control device 18 controls the gantry driving device 19 to rotate the rotation frame 17 or tilt the gantry device 10. When tilting the gantry device 10, the control device 18 controls the gantry driving device 19 based on the inclination angle (tilt angle) input to the input interface to rotate the frame around an axis parallel to the Z-axis direction. Rotate 17. The control device 18 knows the rotation angle of the rotating frame 17 based on the output of a sensor (not shown) or the like. Further, the control device 18 provides the rotation angle of the rotating frame 17 to the reconfiguration function 53 and the like as needed. Further, the control device 18 controls the energy bin (reference signal TH) of the DAS 16. The control device 18 may be provided on the gantry device 10 or may be provided on the console device 40.

The gantry driving device 19 includes, for example, a motor and an actuator. The gantry driving device 19 rotates the rotating frame 17 or tilts the gantry device 10, for example. The gantry driving device 19 rotates the rotating frame 17 of the gantry device 10 based on the inclination angle input to the input interface and a rotation instruction from a correction data collection function 57 described later.

The bed device 30 is a device on which a subject P to be scanned is placed and moved, and introduced into the rotating frame 17 of the gantry device 10 . The bed device 30 includes, for example, a base 31, a bed driving device 32, a top plate 33, and a support frame 34. The base 31 includes a housing that supports the support frame 34 movably in the vertical direction (Y-axis direction). The bed driving device 32 includes a motor and an actuator. The bed driving device 32 moves the top plate 33 along the support frame 34 in the longitudinal direction of the top plate 33 (Z-axis direction). Further, the bed driving device 32 moves the top plate 33 in the vertical direction (Y-axis direction). The top plate 33 is a plate-shaped member on which the subject P is placed.

The bed driving device 32 may move not only the top plate 33 but also the support frame 34 in the longitudinal direction of the top plate 33. Further, contrary to the above, the gantry device 10 may be movable in the Z-axis direction, and the rotating frame 17 may be controlled to come around the subject P by moving the gantry device 10. Alternatively, both the gantry device 10 and the top plate 33 may be movable. Further, the X-ray CT apparatus 1 may be an apparatus in which the subject P is scanned in a standing or sitting position. In this case, the X-ray CT apparatus 1 includes a subject support mechanism in place of the bed device 30, and the gantry device 10 rotates the rotating frame 17 about an axial direction perpendicular to the floor surface.

The console device 40 includes, for example, a memory 41, a display 42, an input interface 43, and a processing circuit 50. In the first embodiment, the console device 40 is described as being separate from the gantry device 10, but the gantry device 10 may include some or all of the components of the console device 40.

The memory 41 is realized by, for example, a RAM (Random Access Memory), a semiconductor memory element such as a flash memory, a hard disk, an optical disk, or the like. The memory 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, information regarding the subject P, imaging conditions, correction data collection conditions, and the like. The memory 41 stores, for example, count data regarding a plurality of energy bins transmitted from the gantry device 10. These data may be stored not in the memory 41 (or in addition to the memory 41) but in an external memory with which the X-ray CT apparatus 1 can communicate. The external memory is controlled by a cloud server, for example, when the cloud server that manages the external memory accepts read/write requests.

The display 42 displays various information. For example, the display 42 displays a medical image (CT image) generated by a processing circuit, a GUI (Graphical User Interface) image, etc. that accepts various operations by an operator such as a doctor or a technician. The display 42 is, for example, a liquid crystal display, a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) display, or the like. The display 42 may be provided on the gantry device 10. The display 42 may be of a desktop type, or may be a display device (for example, a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

The input interface 43 accepts various input operations by an operator, and outputs an electrical signal indicating the content of the received input operation to the processing circuit 50. For example, the input interface 43 can be used to determine the examination schedule for the subject P, the collection conditions when collecting detection data or projection data, the reconstruction conditions when reconstructing a CT image, and the conditions when generating a post-processed image from a CT image. It accepts input operations such as image processing conditions, instructions to start collection processing of correction data, instructions to set an ROI to be set in a CT image, and settings of acquisition conditions.

For example, the input interface 43 is realized by a mouse, keyboard, touch panel, drag ball, switch, button, joystick, camera, infrared sensor, microphone, etc. The input interface 43 may be provided in the gantry device 10. Further, the input interface 43 may be realized by a display device (for example, a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

Note that in this specification, the input interface is not limited to one that includes physical operation parts such as a mouse and a keyboard. For example, examples of the input interface include 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 this electrical signal to a control circuit.

The processing circuit 50 controls the overall operation of the X-ray CT apparatus 1, the operation of the gantry apparatus 10, the operation of the bed apparatus 30, and the calibration operation for collecting correction data. The processing circuit 50 includes, for example, a system control function 51, a preprocessing function 52, a reconstruction function 53, an image processing function 54, and the like.

These components are realized, for example, by a hardware processor (computer) executing a program (software) stored in the memory 41. A hardware processor is, for example, a CPU, a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), a programmable logic device (for example, a Simple Programmable Logic Device (SPLD)), or a complex programmable logic device ( Refers to circuits such as Complex Programmable Logic Devices (CPLDs) and Field Programmable Gate Arrays (FPGAs). Instead of storing the program in the memory 41, the program may be directly incorporated into the circuit of the hardware processor.

In this case, the hardware processor realizes its functions by reading and executing a program built into the circuit. The hardware processor is not limited to being configured as a single circuit, but may be configured as one hardware processor by combining a plurality of independent circuits to realize each function. Further, a plurality of components may be integrated into one hardware processor to realize each function.

Each component included in the console device 40 or the processing circuit 50 may be distributed and realized by a plurality of pieces of hardware. The processing circuit 50 may be realized by a processing device that can communicate with the console device 40 instead of the configuration that the console device 40 has. The processing device is, for example, a workstation connected to one X-ray CT device, or a device that is connected to multiple X-ray CT devices and collectively executes the same processing as the processing circuit 50 described below. For example, a cloud server).

The system control function 51 controls various functions of the processing circuit 50 based on input operations received by the input interface 43.

The preprocessing function 52 performs preprocessing such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, beam hardening correction, scattered radiation correction, and dark count correction on the detection data output by the DAS 16. Projection data is generated by The projection data includes count data.

The reconstruction function 53 performs reconstruction processing on the projection data generated by the preprocessing function 52 using a filtered back projection method, a successive approximation reconstruction method, or the like to generate CT image data. The reconstruction function 53 stores the reconstructed CT image data in the memory 41. The reconstruction function 53 may perform reconstruction processing using detection data (count data) when the preprocessing function 52 does not perform preprocessing.

The reconstruction function 53 generates CT image data based on the detection data output by the DAS 16, for example. The CT image data is, for example, data of a cross-sectional image (hereinafter referred to as an axial image) of an arbitrary cross section, for example, an axial cross section perpendicular to the body axis of the subject P. The CT image data may be data of a cross-sectional image of another cross section, or data of a three-dimensional image. The three-dimensional image may have been rendered. The reconstruction function 53 may convert CT image data into three-dimensional image data when generating three-dimensional image data. Conversion to this conversion may be performed by a pre-processing function 52.

FIG. 3 is a diagram showing an example of functional blocks of the reconfiguration function 53 according to the embodiment. The reconstruction function 53 includes, for example, a response function generation function 531, an X-ray absorption amount calculation function 532, and a reconstruction processing function 533. The response function generation function 531 generates response function data representing detector response characteristics. For example, the response function generation function 531 calculates the response (i.e., detection energy and detection intensity) of a standard detection system to a plurality of monochromatic X-rays having a plurality of incident A response function is generated based on the measured values of detected energy and detected intensity. Further, the response function generation function 531 may generate response function data based on actual measurement values collected during calibration or the like. The response function defines the relationship between the detected energy for each incident x-ray and the output response of the system. For example, the response function defines the relationship between detected energy and detected intensity for each incident X-ray. The generated response function data is stored in the memory 41.

The X-ray absorption amount calculation function 532 calculates a plurality of bases based on the count data regarding the plurality of energy bins included in the projection data, the energy spectrum of the incident X-rays on the subject P, and the response function stored in the memory 41. Calculate the amount of X-ray absorption for each substance. The X-ray absorption amount calculation function 532 uses a response function to calculate the X-ray absorption amount based on the count data and the energy spectrum of the incident X-rays on the subject P. It is possible to calculate the amount of X-ray absorption that is not affected by the response characteristics of. The process of obtaining the X-ray absorption amount for each base substance is also called substance discrimination.

The base substance can be set to any substance such as calcium, calcification, bone, fat, muscle, air, organ, lesion, hard tissue, soft tissue, contrast material, etc. When multiple types of contrast substances are used as the base substance, each contrast substance can be set as the base substance. The type of base material to be calculated may be determined in advance by an operator or the like via the input interface 43. The contrast material includes, for example, at least one of gadolinium, gold, and bismuth. The contrast substance does not need to contain these substances. The X-ray absorption amount indicates the amount of X-rays absorbed by the base material. For example, the amount of X-ray absorption is defined by the combination of the X-ray attenuation coefficient and the X-ray transmission path length.

The reconstruction processing function 533 calculates the spatial distribution of the base substance to be imaged among the plurality of base substances based on the X-ray absorption amount for each of the plurality of base substances calculated by the X-ray absorption amount calculation function 532. The CT image data to be expressed is reconstructed and stored in the memory 41. The base substance to be imaged in the embodiment includes two types of contrast substances, but may include different types of contrast substances, or three or more types of contrast substances. For example, the base substance to be imaged may be set in advance or may be determined by an operator or the like via the input interface 43.

The projection data including count data obtained by the photon counting CT apparatus includes information on the energy of the X-rays attenuated by passing through the subject P. Therefore, the reconstruction processing function 533 can reconstruct CT image data of a specific energy component, for example. Furthermore, the reconstruction processing function 533 can, for example, reconstruct CT image data of each of a plurality of energy components. Furthermore, the reconstruction processing function 533 assigns a color tone according to the energy component to each pixel of the CT image data of each energy component, and generates image data in which a plurality of CT image data color-coded according to the energy component are superimposed. can be generated.

Returning to FIG. 1, the image processing function 54 generates a CT image based on CT image data. The image processing function 54 displays the generated CT image on the display 42. The image processing function 54 acquires information regarding the flow state of the contrast material flowing into the target organ of the subject P. The image processing function 54 causes the display 42 to display the generated inflow state information.

FIG. 4 is a diagram showing an example of functional blocks of the image processing function 54 according to the embodiment. The image processing function 54 includes, for example, a reception function 542, a first acquisition function 541, a setting function 543, a specific function 544, a scan control function 545, a second acquisition function 546, a determination function 547, and a presentation function. 548. The presentation function 548 includes, for example, a display control function 548A and an audio output function 548B.

The first acquisition function 541 acquires the axial image data generated by the reconstruction function 53. The axial image data is wide-area image data including the ROI of the subject P. The axial image data is, for example, data based on a plurality of pieces of information in which substances are discriminated based on count data of each energy bin in which photons are detected by the X-ray detector 15. The first acquisition function 541 is an example of a first acquisition unit. The count data is an example of a count result. The first acquisition function 541 may directly acquire the axial image data generated by the reconstruction function 53.

The reception function 542 receives an instruction to set an ROI indicated by an electrical signal output by the input interface 43 in response to an input operation by an operator. The ROI set in the axial image is set for the target organ into which the contrast material is injected. The ROI setting instruction may be an instruction based on the name of the target organ serving as the ROI, or may be an instruction based on specifying a site in an axial image. When specifying a region in the axial image, the reception function 542 may display the axial image on the display 42. An ROI is set for each target organ, and if there are multiple target organs, multiple ROIs are set.

For example, the number of contrast substances to be injected into a target organ may be one, multiple, or one for a plurality of target organs. Both a contrast substance to be injected and a contrast substance not to be injected are injected into the target organ. The reception function 542 is an example of a reception unit.

The setting function 543 sets an ROI in the axial image based on the ROI setting instruction received by the reception function 542. The setting function 543 sets the ROI at a position corresponding to a setting instruction according to an input operation by an operator, for example. The setting function 543 sets the ROI in an arbitrary shape, such as a circular shape, a rectangular shape, or an elliptical shape, according to the setting instruction. The setting function 543 is an example of a setting section.

The setting function 543 may set the ROI based on the axial image, for example, without depending on the ROI setting instruction. In this case, the setting function 543 acquires information specifying the target organ to be set as the ROI, and uses pattern matching using pattern images of the designated target organ, a trained model obtained by machine learning, etc. to set the ROI. may be set.

The specifying function 544 specifies an area to be updated in the axial image based on the ROI setting instruction received by the receiving function 542. The specifying function 544 specifies the update target area, for example, based on the set ROI. The specifying function 544 specifies, for example, a circular update target area that includes the set ROI.

The update target area in the axial image is the irradiation area where the X-ray tube 11 irradiates the subject P with X. The update target area is narrower than the area to which the X-ray tube 11 irradiated X-rays when the axial image was taken. The axial image is an example of a wide-area medical image that includes an object of interest of a subject. The wide-area medical image including the object of interest of the subject may be a CT image other than an axial image, such as a scanogram, sagittal image, coronal image, or oblique image.

The area of the update target region may be predetermined or may be determined based on the size of the ROI or the like. The location for specifying the update target area may be any location that includes the ROI. For example, the center of gravity of the ROI may be the center point of the area to be updated, so that the ROI may be located at the center of the area to be updated.

The specifying function 544 may specify the region to be updated based on the user's ROI setting instruction outputted from the input interface 43 . The input interface 43 may be capable of inputting the position and size of the update target area specified by the user. The identification function 544 may identify the ROI in a shape other than a circular shape. The specific function 544 is an example of a specific part.

The scan control function 545 controls the detection data collection process in the gantry device 10 by instructing the X-ray high voltage device 14, DAS 16, control device 18, gantry driving device 19, and bed driving device 32. The scan control function 545 controls the operations of each part when capturing a positioning image and capturing an image used for diagnosis.

The scan control function 545 performs, for example, control for photographing an axial image and control for photographing an inspection image. In the control for photographing an axial image, the scan control function 545 instructs the control device 18 to perform simple photographing such as a helical scan or a volume scan. The DAS 16 outputs various detection data to the processing circuit 50 according to instructions from the scan control function 545.

The scan control function 545 generates time sequence information based on the examination schedule for the subject P indicated by the electrical signal output by the input interface 43. The time sequence information includes, for example, information on the type of contrast material to be injected, the injection timing for injecting the contrast material, and the scan time required for scanning to generate an examination image of the target organ. When a plurality of contrast substances are injected, they may be injected simultaneously or sequentially. The time sequence information may set the type and injection timing of the contrast material in case of simultaneous injection or sequential injection.

When a plurality of contrast substances are injected into the subject P, information on injection timing and scan time is included for each contrast substance. The time sequence information may include an estimated time until the concentration of the contrast material to be injected in the target organ reaches a threshold value or more. The scan control function 545 performs display control to display the generated time sequence information on the display 42. The time sequence information includes injection timing for each contrast substance, and the scan control function 545 causes the display 42 to display the injection timing for each contrast substance. The user refers to the time sequence information displayed on the display 42 to recognize the injection timing of the contrast material.

In the control for photographing the inspection image, the scan control function 545 performs real prep using interior CT in which the X-ray irradiation area is limited to the update target area in accordance with the generated time sequence information. The interior CT here is a CT in which X-ray irradiation is performed in a narrower area to be updated than in a CT image (axial image). The real prep here is a process in which the scan of the update target area, that is, the irradiation of X-rays by the X-ray tube 11 and the reconstruction of CT image data by the reconstruction function 53 are repeatedly performed at intervals. In real prep, the update target area is repeatedly scanned at intervals of, for example, about 1 second.

Real Prep also performs material decomposition. In material decomposition, the concentration of contrast material in the target organ is calculated. The scan control function 545 adjusts the aperture of the collimator 13 to adjust the irradiation range of X-rays when causing the X-ray tube 11 to irradiate the update target area with X-rays. The scan control function 545 is an example of a scan control section.

The second acquisition function 546 acquires CT image data obtained by interior CT (hereinafter referred to as interior CT image data). The interior CT image data is generated, for example, by the reconstruction function 53 based on output data output by the DAS 16 when interior CT is performed.

The interior CT image data is information regarding the inflow state of a plurality of contrast substances, which are discriminated based on the count data of each energy bin in which the X-ray detector 15 detects photons derived from irradiating the irradiation area with X-rays. This is data based on. Conditions are set for photon count data collected by energy bins for each of a plurality of contrast substances. The conditions for the count data are set, for example, for the calculation results when a predetermined calculation is performed on the count data collected by each energy bin. The interior CT image data includes image data of an image of contrast material flowing into the ROI. The second acquisition function 546 may acquire the interior CT image data stored in the memory 41 or may directly acquire it using the reconstruction function 53.

The second acquisition function 546 calculates and acquires the concentration of the contrast material in the ROI based on the X-ray absorption amount calculated for each contrast material flowing into the ROI included in the interior CT image data. The second acquisition function 546 calculates, for example, the density of the contrast material becomes higher as the amount of X-ray absorption increases. The second acquisition function 546 is an example of a second acquisition unit. The image and density of the contrast material that has flowed into the ROI are examples of information regarding the flow state of the contrast material. The concentration of contrast material flowing into the ROI is an example of a measurement regarding contrast material.

The determination function 547 calculates the density of the contrast material within the update target area based on the interior CT image data acquired by the second acquisition function 546. The determination function 547 terminates the real prep when the calculated contrast material concentration is equal to or higher than the threshold value, and performs a scan (hereinafter referred to as , main scan). In this scan, the update target area is scanned more frequently than in real prep.

The determination function 547 starts scanning the target organ when it receives an electrical signal output from the input interface 43 indicating an instruction to start the main scan instead of or in addition to the case where the concentration of the contrast material is equal to or higher than the threshold value. It's okay. In this case, the display control function 548A causes the display 42 to display an image in which the interior CT image is superimposed on the axial image (hereinafter referred to as a superimposed image). The user visually estimates the concentration of the contrast material in the target organ by looking at the superimposed image displayed on the display 42, and when the user determines that the concentration of the contrast material is the concentration required for imaging, the user issues an instruction to start the main scan. The input operation may be performed using the input interface 43. The determination function 547 may start the main scan when determining that the X-ray absorption amount of the ROI is equal to or greater than a threshold value based on the X-ray absorption amount of the ROI instead of the concentration of the contrast material.

A display control function 548A in the presentation function 548 performs display control to display a CT image based on CT image data on the display 42. For example, the display control function 548A causes the display 42 to display an axial image based on the axial image data acquired by the first acquisition function 541. The display control function 548A causes the display 42 to display, for example, a superimposed image in which the interior CT image acquired by the second acquisition function 546 is superimposed on the axial image.

For example, when displaying the concentration of the contrast material, the display control function 548A displays the change in the concentration of the contrast material over time numerically or in a graph on the display 42. The display control function 548A further causes the display 42 to display various images (photographed images, positioning images, input operation results received by the input interface 43, etc.). The display control function 548A is an example of a display control section.

When interior CT image data is acquired by the second acquisition function 546, the audio output function 548B outputs information regarding the inflow state of the contrast substance, such as the name of the contrast substance to be displayed on the display 42. The output is output to a speaker (not shown). The audio output function 548B is an example of an audio output unit. The presentation function 548 may present information regarding the inflow state of the contrast material as information other than an image displayed on the display 42 or audio outputted from the speaker. The presentation function 548 is an example of a presentation section.

Next, the flow of testing the subject P using the X-ray CT apparatus 1 will be explained. In the following explanation, two organs, for example, an artery and a vein, are the first target organ and the second target organ, respectively, the contrast material flows from the artery to the vein through the intestinal tract, the first ROI is set to the first target organ, and the second ROI is set to the first target organ. An example in which the second ROI is set to the target organ will be described. Further, the concentration of the first contrast substance in the first target organ that is necessary for imaging the first target organ is set as a first threshold value, and the second contrast substance in the second target organ that is necessary for imaging the second target organ is set as a first threshold value. The concentration of is set as the second threshold value.

FIG. 5 is a diagram showing an example of the flow of testing a subject P using the X-ray CT apparatus 1. When testing the subject P, first, the top plate 33 of the bed device 30 on which the subject P is mounted is introduced into the rotating frame 17 of the gantry device 10 (step S101). Subsequently, a scan is performed in the X-ray CT apparatus 1 to capture an axial image of the subject P (step S103).

Subsequently, a user such as a doctor injects a contrast material into the subject P according to the content of the examination (step S105). The injection timing for injecting the contrast material is the injection timing indicated by the time sequence information generated by the scan control function 545 based on the examination schedule output by the input interface 43. The injection timing is set for each of the first contrast substance and the second contrast substance. When the contrast material is injected into the subject P, the X-ray CT apparatus 1 performs real prep and observes the inflow of the contrast material into the target organ by material decomposition (step S107).

Subsequently, when the injection of the contrast material into the target organ is completed, the X-ray CT apparatus 1 captures an examination image of the target organ (step S109). Once the examination image of the target organ is acquired, the examination of the object P mounted on the top plate 33 is evacuated from inside the rotating frame 17 of the gantry device 10 (step S111), thereby completing the examination of the object P.

Next, the processing in the X-ray CT apparatus 1 when the subject P is examined will be explained. FIG. 6 is a flowchart showing an example of processing in the X-ray CT apparatus 1. In the X-ray CT apparatus 1, first, the first acquisition function 541 of the processing circuit 50 acquires an electrical signal including an examination schedule outputted from the input interface 43. The scan control function 545 generates time sequence information based on the examination schedule indicated by the electrical signal acquired by the first acquisition function 541, and displays it on the display 42 (step S201).

Subsequently, the reconstruction function 53 reconstructs the detection data output by the DAS 16 to generate an axial image of the subject P (step S203), and the first acquisition function 541 generates an axial image of the subject P generated by the reconstruction function 53. Acquire an axial image. When generating an axial image, the X-ray CT apparatus 1 generates a single axial image or a three-dimensional axial image as an axial image by simple imaging such as a helical scan or a volume scan. Before the reconstruction function 53 generates the axial image, preprocessing in the preprocessing function 52 may be performed.

After the reconstruction function 53 acquires detection data for generating an axial image, a contrast material is injected into the subject P by a user or the like. A contrast substance may be injected into the subject P before the reconstruction function 53 acquires detection data for generating an axial image. As the axial image, for example, an image before the contrast material flows into the target organ is used.

Subsequently, the setting function 543 sets a first ROI and a second ROI in the axial image based on the ROI setting instruction received by the reception function 542 (step S205). The ROI setting instruction may be included in the inspection schedule, or may be included in the electrical signal output by the input interface 43 separately from the inspection schedule.

Subsequently, the specifying function 544 specifies an area to be updated in the axial image in which the ROI has been set (step S207). Next, after the area to be updated has been specified, the scan control function 545 generates time sequence information based on the inspection schedule output by the input interface 43, and performs real-time analysis using interior CT in accordance with the generated time sequence information. Preparation is started (step S209), and the inflow of the first contrast material into the first target organ is observed by material decomposition. The display control function 548A displays the visualized superimposed image on the display 42 while the scan control function 545 is performing real prep.

While performing this real prep, the scan control function 545 adjusts the collimator 13 so that the area irradiated with X-rays by the X-ray tube 11 is limited to the update target area specified by the specifying function 544. In material decomposition in real prep, the scan control function 545 scans the subject at regular time intervals, and the reconstruction function 53 generates interior CT image data.

Subsequently, the determination function 547 collects data within the first ROI in the interior CT image data. The determination function 547 calculates the concentration of the first contrast material in the first target organ based on the collected data, and determines whether the calculated concentration is equal to or higher than the first threshold (step S211). Here, the collection of data by the determination function 547 will be explained in relation to the superimposed image displayed on the display 42 by the display control function 548A.

FIG. 7 is a diagram showing an example of a visualized superimposed image 200 and a graph explaining data collection. The superimposed image 200 includes a first ROI 201 and a second ROI 202. The first ROI 201 is set at a position corresponding to a vein of the subject P, for example, and the second ROI 202 is set at a position corresponding to an artery of the subject P, for example. An area to be updated 210 is specified as an area including the first ROI 201 and the second ROI 202. The interior CT image data is data corresponding to an image within the update target area 210.

For example, the determination function 547 prepares N energy bins (bin1, bin2, ... binN) with different threshold values for discriminating the energy of X-ray photons, and selects X-ray photons at corresponding positions within the first ROI 201. into N energy bins. The determination function 547 counts the number of X-ray photons discriminated for each energy amount, and calculates the concentration of the first contrast material based on the count data.

As a result, if the determination function 547 determines that the concentration of the first contrast substance in the first target organ is not equal to or higher than the first threshold value, the scan control function 545 continues the real prep. On the other hand, when the determination function 547 determines that the concentration of the first contrast material in the first target organ is equal to or higher than the first threshold value, the scan control function 545 determines that the injection of the second contrast material into the first target organ has been completed. A main scan (hereinafter referred to as a first main scan) for determining and generating an examination image of the first target organ is started (step S213). Next, the scan control function 545 refers to the time sequence information to check the time required for the first scan (hereinafter referred to as the first scan time), and determines whether the first scan time has elapsed. (Step S215).

If it is determined that the first main scan time has not elapsed, the scan control function 545 continues the first main scan. If it is determined that the first main scan time has elapsed, the scan control function 545 restarts the real prep (step S217) and observes the inflow of the second contrast material into the second target organ.

Subsequently, the determination function 547 calculates the concentration of the second contrast substance in the second target organ based on the data in the second ROI in the interior CT image data, and determines whether the calculated concentration is equal to or higher than the second threshold value. is determined (step S219). As shown in FIG. 7, the determination function 547 discriminates, for example, X-ray photons at corresponding positions within the second ROI 202 into N energy bins. The determination function 547 counts the number of X-ray photons discriminated for each energy amount, and calculates the concentration of the second contrast material based on the count data.

When the determination function 547 determines that the concentration of the second contrast substance in the second target organ is not equal to or higher than the second threshold value, the scan control function 545 continues the real prep. On the other hand, when the determination function 547 determines that the concentration of the second contrast material in the second target organ is equal to or higher than the second threshold value, the scan control function 545 determines that the injection of the second contrast material into the second target organ has been completed. A main scan (hereinafter referred to as a second main scan) for determining and generating an inspection image of the second target organ is started (step S211).

Next, the scan control function 545 refers to the time sequence information, checks the time required for the second scan (hereinafter referred to as second scan time), and determines whether the second scan time has elapsed. (Step S215). If it is determined that the second main scan time has not elapsed, the scan control function 545 continues the second main scan. If it is determined that the second main scan time has elapsed, the X-ray CT apparatus 1 ends the process shown in FIG. 6.

The X-ray CT apparatus 1 of the embodiment determines the concentration of the contrast material in the target organ by performing real prep including material decomposition after starting injection of the contrast material. Therefore, the injection status such as the concentration of the contrast material into the target organ can be easily understood.

Moreover, the X-ray CT apparatus 1 of the embodiment limits the irradiation range of X-rays by the X-ray tube 11 when performing real prep to a narrow update target area by interior CT. Therefore, since the amount of X-ray irradiation can be reduced, the amount of radiation that the subject P is exposed to when performing real prep can be reduced.

The X-ray CT apparatus 1 of the embodiment injects a contrast substance into a target organ, and then uses interior CT to reduce the X-ray irradiation range of the X-ray tube 11 to a narrow update target area in order to measure the concentration of the contrast substance. Limited. Therefore, since the amount of X-ray irradiation can be reduced, the amount of radiation to which the subject P is exposed can be reduced.

If interior CT is performed and the X-ray irradiation range is limited to a narrow update target area, the calculated value of the X-ray absorption amount within the update target area will be incorrect due to truncation when reconstructing the X-ray image. May be stable. In this case, the accuracy of the calculated value of the contrast substance concentration in the target organ becomes low.

In this regard, in the X-ray CT apparatus 1 of the embodiment, after starting injection of the contrast material, real prep including material decomposition is performed to determine the concentration of the contrast material in the target organ. Therefore, the injection status such as the concentration of the contrast material into the target organ can be easily understood.

Moreover, the X-ray CT apparatus 1 of the embodiment is a photon counting X-ray CT apparatus that performs photon counting. Therefore, when a plurality of contrast substances are injected, the concentration of the contrast substances can be calculated by measuring the amount of X-ray absorption for each type of contrast substance. Therefore, even if multiple contrast substances are injected into the subject P at the same time, it is easy to calculate the concentration of the contrast substance for each type of contrast substance or for each target organ into which the contrast substance is injected. can do.

Although the X-ray CT apparatus 1 of the embodiment is a photon counting CT apparatus that performs photon counting, the X-ray CT apparatus may be a CT apparatus other than the photon counting CT apparatus. The X-ray CT apparatus may be, for example, a dual-energy CT apparatus that acquires information regarding the inflow of a plurality of contrast substances based on the obtained results of irradiating an irradiation area with a plurality of X-rays having different energies.

In the embodiments described above, gadolinium, gold, and bismuth are used as contrast substances, and these contrast substances have a higher X-ray absorption amount than water. On the other hand, the contrast substance may be a substance that absorbs X-rays lower than water, for example, physiological saline, and the contrast substance may be any substance that assists in contrasting the target organ. In the above embodiments, the axial image is an image obtained by simple imaging using a normal CT scan, but the axial image may be an axial image obtained by, for example, a 3D landmark scan.

According to at least one embodiment described above, the first acquisition unit acquires medical image data regarding a wide-area medical image including an object of interest of a subject; a specifying unit that specifies an irradiation area that is narrower than the irradiation area and is a target for irradiating X-rays; a scan control unit that repeatedly irradiates the irradiation area with the X-rays and photographs the irradiation area; By including the second acquisition unit that acquires information regarding the flow state of the contrast material flowing into the object, it is possible to easily distinguish the photographed contrast material.

Although several embodiments have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1... X-ray CT device 10... Frame device 11... X-ray tube 12... Wedge 13... Collimator 14... X-ray high voltage device 14A... High voltage generator 14B... X-ray control device 15... X-ray detector 16... DAS
17... Rotating frame 18... Control device 19... Frame drive device 30... Bed device 31... Base 32... Bed drive device 33... Top plate 34... Support frame 40... Console device 41... Memory 42... Display 43... Input interface 50... Processing circuit 51...System control function 52...Preprocessing function 53...Reconfiguration function 54...Image processing function 57...Correction data collection function 61...Preamplifier circuit 63...Waveform shaping circuit 65...Wave height discrimination circuit 65-n...Wave height Discrimination circuit 67...Counting circuit 67-n...Counting circuit 69...Output circuit 200...Superimposed image 201...First ROI
202...Second ROI
210...Update target area 531...Response function generation function 532...X-ray absorption amount calculation function 533...Reconstruction processing function 541...First acquisition function 542...Reception function 543...Setting function 544...Specific function 545...Scan control function 546... Second acquisition function 547...Judgment function 548...Presentation function 548A...Display control function 548B...Audio output function 653-1...Comparison circuit 653-2...Comparison circuit 653-n...Comparison circuit P...Subject

Claims (14)

a first acquisition unit that acquires medical image data regarding a wide area medical image including an object of interest of the subject;
a specifying unit that specifies an irradiation area that includes an area of interest corresponding to the object of interest, is narrower than the wide area, and is a target for irradiating X-rays;
a scan control unit that repeatedly irradiates the irradiation area with the X-ray and photographs the irradiation area;
a second acquisition unit that acquires information regarding the inflow state of the contrast material flowing into the object of interest;
X-ray CT device. The information regarding the inflow state of the contrast substance includes at least one of an image of the contrast substance included in an image of the irradiation area or a measurement value regarding the contrast substance.
The X-ray CT apparatus according to claim 1. further comprising a presentation unit that presents information regarding the inflow state of the contrast substance;
The X-ray CT apparatus according to claim 1. further comprising a setting unit that sets the object of interest in the medical image;
The X-ray CT apparatus according to claim 1. a display control unit that controls display of the medical image;
further comprising a reception unit that receives an instruction of the object of interest to be set in the medical image;
The X-ray CT apparatus according to claim 1. The second acquisition unit is configured to determine the inflow state of the plurality of contrast substances that have been subjected to material discrimination based on the counting results of each energy bin in which a photon counting detector has detected photons derived from irradiating the irradiation area with X-rays. get information about,
The X-ray CT apparatus according to claim 1. The contrast substance includes at least one of gadolinium, gold, and bismuth.
The X-ray CT apparatus according to claim 6. Conditions for counting results of photons collected by the energy bins are set for each of the plurality of contrast substances,
The X-ray CT apparatus according to claim 6. The scan control unit generates time sequence information including information on the type and injection timing of the contrast substance to be injected into the subject.
The X-ray CT apparatus according to claim 6. The scan control unit displays and controls the injection timing for each contrast substance,
The X-ray CT apparatus according to claim 9. The second acquisition unit acquires information regarding the inflow of the plurality of contrast substances based on the obtained results of irradiating the irradiation area with each of the plurality of X-rays having different energies.
The X-ray CT apparatus according to claim 1. The specifying unit specifies the irradiation area including the region of interest in a medical image acquired before setting the irradiation area.
The X-ray CT apparatus according to claim 1. The computer is
Obtaining medical image data regarding a wide area medical image including the object of interest of the subject,
identifying an irradiation area that includes a region of interest corresponding to the target of interest, is narrower than the wide area, and is a target for irradiating X-rays;
repeatedly irradiating the irradiation area with the X-rays and photographing the irradiation area;
obtaining information regarding the inflow state of the contrast material flowing into the object of interest;
A method of controlling an X-ray CT device. to the computer,
Obtaining medical image data regarding a wide area medical image including the object of interest of the subject,
identifying an irradiation area that includes a region of interest corresponding to the object of interest, is narrower than the wide area, and is a target for irradiating X-rays;
repeatedly irradiating the irradiation area with the X-rays and photographing the irradiation area;
obtaining information regarding an inflow state of contrast material flowing into the object of interest;
program.

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