JP2022040860A - X-ray ct apparatus and data transfer method - Google Patents

Abstract

To reduce a waiting time of a user.SOLUTION: An X-ray CT apparatus in an embodiment includes a buffer, an acquisition part and a determination part. The buffer stores temporarily data detected by an X-ray detector. The acquisition part acquires information on a residual quantity of the buffer before executing scanning shown in a scan plan. The determination part determines data transfer timing from the buffer to a storage part based on the scan plan and on the information on the residual quantity of the buffer.SELECTED DRAWING: Figure 1

Description

The embodiments disclosed in the present specification and the drawings relate to an X-ray CT apparatus and a data transfer method.

In recent years, the amount of data acquired by an X-ray CT (Computed Tomography) device in one imaging has increased. Then, if there is a difference between the data acquisition speed and the transfer speed of the acquired data, it is necessary to arrange a buffer to compensate for the difference. However, there are inconveniences such as increased power consumption as the size of the buffer increases. Therefore, it is necessary to prevent the buffer storage capacity from becoming large.

Japanese Patent No. 5611667

One of the problems to be solved by the embodiments disclosed in the present specification and the drawings is to scan a subject while suppressing an increase in the storage capacity of the buffer. However, the problems to be solved by the embodiments disclosed in the present specification and the drawings are not limited to the above problems. The problem corresponding to each effect by each configuration shown in the embodiment described later can be positioned as another problem.

The X-ray CT apparatus according to the embodiment includes a buffer, an acquisition unit, and a determination unit. The buffer temporarily stores the data detected by the X-ray detector. The acquisition unit acquires information regarding the remaining amount of the buffer before executing the scan indicated in the scan plan. The determination unit determines the transfer timing of data from the buffer to the storage unit based on the scan plan and the information regarding the remaining amount of the buffer.

FIG. 1 is a block diagram showing an example of the configuration of the X-ray CT apparatus according to the first embodiment. FIG. 2 is a timing chart showing an example of a scan plan and a transfer plan. FIG. 3 is a block diagram showing an example of the configuration of the DAS according to the first embodiment. FIG. 4 is a flowchart showing an example of the transfer process executed by the X-ray CT apparatus according to the first embodiment. FIG. 5 is a block diagram showing an example of the configuration of the X-ray CT apparatus according to the second embodiment. FIG. 6 is a block diagram showing an example of the configuration of the relay device according to the second embodiment.

Hereinafter, the X-ray CT apparatus and the data transfer method according to the present embodiment will be described with reference to the drawings. In the following embodiments, the parts with the same reference numerals perform the same operation, and duplicate description will be omitted as appropriate.

(First Embodiment)
FIG. 1 is a block diagram showing an example of the configuration of the X-ray CT apparatus 1 according to the first embodiment. The X-ray CT apparatus 1 is an image diagnostic apparatus having a high-resolution X-ray detector 12 and acquiring a high-definition image. The X-ray CT device 1 includes a gantry device 10, a sleeper device 30, and a console device 40. The gantry device 10 transfers the data acquired by scanning the subject P to the console device 40. Then, the console device 40 generates CT image data by reconstructing the data received from the gantry device 10.

Since the X-ray CT apparatus 1 has a high-resolution X-ray detector 12, the amount of data to be acquired also increases. As the amount of data increases, the acquisition rate of data acquired by the X-ray CT apparatus 1 per unit time may exceed the data transfer rate. However, if the acquisition rate is lowered according to the transfer rate, the X-ray CT apparatus 1 takes a long time to scan the subject P. Therefore, the X-ray CT apparatus 1 temporarily stores the acquired data in the buffer, and transfers the data stored in the buffer. As a result, the X-ray CT apparatus 1 can transfer the acquired data without lowering the acquisition rate.

Here, the X-ray CT apparatus 1 has various imaging protocols. The amount of data acquired depends on the imaging protocol. Then, in order to store all the data acquired by the imaging protocol having the largest amount of data, the X-ray CT apparatus 1 must include a buffer having a large storage capacity. On the other hand, there is a desire to reduce the storage capacity of the buffer due to reasons such as heat generation, power consumption, mounting area, and manufacturing cost.

However, if the storage capacity of the buffer is reduced, the storage capacity of the buffer may be insufficient. When the storage capacity of the buffer becomes insufficient, the X-ray CT apparatus 1 must stop scanning the subject P in order to prevent the data from being overwritten. However, the X-ray CT apparatus 1 may not be able to stop scanning the subject P. For example, when the contrast medium is injected and the subject P is scanned, if the scan of the subject P is stopped, the X-ray CT apparatus 1 cannot take an intended image because the contrast medium flows. Therefore, there is a demand for a technique capable of scanning a subject P while suppressing an increase in the storage capacity of the buffer.

In the first embodiment, a case where it is applied to the X-ray CT apparatus 1 for acquiring a high-definition image will be described as an example. However, the X-ray CT apparatus 1 may acquire data by a PC (Photon Counting) method, or may acquire data by another format.

Further, in the first embodiment, the rotation axis of the rotation frame 13 in the non-tilt state or the longitudinal direction of the top plate 33 of the sleeper device 30 is orthogonal to the Z-axis direction and the Z-axis direction, and is horizontal to the floor surface. It is assumed that a certain axial direction is orthogonal to the X-axis direction and the Z-axis direction, and the axial direction perpendicular to the floor surface is defined as the Y-axis direction, respectively.

The gantry device 10 has an imaging system for capturing a medical image used for diagnosis. That is, the gantry device 10 is a device having an imaging system that irradiates the subject P with X-rays and collects projection data from the detection data of the X-rays transmitted through the subject P. The X-ray tube 11 and the wedge 16 It has a collimeter 17, an X-ray detector 12, an X-ray high voltage device 14, a DAS (Data Acquisition System) 18, a rotating frame 13, a control device 15, and a sleeper device 30.

The X-ray tube 11 is a vacuum tube that irradiates thermoelectrons from the cathode (filament) toward the anode (target) by applying a high voltage from the X-ray high voltage device 14.

The wedge 16 is a filter for adjusting the X-ray dose of X-rays emitted from the X-ray tube 11. Specifically, the wedge 16 transmits and attenuates the X-rays emitted from the X-ray tube 11 so that the X-rays emitted from the X-ray tube 11 to the subject P have a predetermined distribution. It is a filter to do.

The wedge 16 is, for example, a wedge filter or a bow-tie filter, which is a filter obtained by processing aluminum so as to have a predetermined target angle and a predetermined thickness.

The collimator 17 is a lead plate or the like for narrowing the irradiation range of X-rays transmitted through the wedge 16, and a slit is formed by a combination of a plurality of lead plates or the like.

The X-ray detector 12 detects X-rays irradiated from the X-ray tube 11 and passed through the subject P, and outputs an electric signal corresponding to the X-ray dose to the data acquisition device (DAS18). The X-ray detector 12 has, for example, a plurality of X-ray detection element trains in which a plurality of X-ray detection elements are arranged in a channel direction along one arc centering on the focal point of the X-ray tube 11. The X-ray detector 12 has, for example, a plurality of X-ray detection element trains in which a plurality of X-ray detection elements are arranged in a channel direction along one arc centering on the focal point of the X-ray tube 11. The X-ray detector 12 has, for example, a structure in which a plurality of X-ray detection element sequences in which a plurality of X-ray detection elements are arranged in the channel direction are arranged in a slice direction (also referred to as a body axis direction or a column direction).

Further, the X-ray detector 12 is an indirect conversion type detector having, for example, a grid, a scintillator array, and an optical sensor array. The scintillator array has a plurality of scintillators, and the scintillator has a scintillator crystal that outputs a photon amount of light according to an incident X dose. The grid is arranged on the X-ray incident side surface of the scintillator array and has an X-ray shield plate having a function of absorbing scattered X-rays. The optical sensor array has a function of converting into an electric signal according to the amount of light from the scintillator, and has, for example, an optical sensor such as a photomultiplier tube (PMT). The X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electric signal.

The X-ray high-voltage device 14 has an electric circuit such as a transformer and a rectifier, and has a function of generating a high voltage applied to the X-ray tube 11 and an irradiation by the X-ray tube 11. It has an X-ray control device that controls the output voltage according to the X-ray. The high voltage generator may be 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. The fixed frame is a frame that rotatably supports the rotating frame 13.

The DAS 18 acquires detection data based on an electric signal output from each X-ray detection element of the X-ray detector 12. The detection data acquired by the DAS 18 is transferred to the console device 40. In addition, in FIG. 3, the detailed configuration of DAS 18 will be described.

Here, the detection data is a general term for the data acquired by the DAS 18 based on the electric signal output from the X-ray detector 12. Here, in the detection data, a set of one or more scan data included in the same scan plan is referred to as a scan data set. The scan plan is a plan for scanning the subject P specified by the imaging protocol and includes one or more scans. Further, the scan in the present embodiment means a series of operations in which X-ray irradiation and X-ray detection are repeatedly executed at continuous projection positions (view numbers). Therefore, if the view number is reset and X-ray irradiation and X-ray detection are repeatedly executed with a new continuous view number, another scan is performed. Further, the scan data is, for example, a set of data acquired by a series of scans in which continuous numbers are assigned in view numbers indicating projection positions. In addition to the classification of scan units, the scan data can be, for example, a group of data obtained by dividing a scan data set into a plurality of arbitrary data.

The rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 so as to face each other and rotates the X-ray tube 11 and the X-ray detector 12 by the control device 15. The rotating frame 13 may further support the X-ray high voltage device 14 and the DAS 18 in addition to the X-ray tube 11 and the X-ray detector 12. The detection data acquired by the DAS 18 is, for example, a photo provided in a non-rotating portion of a gantry device 10 such as a fixed frame by optical communication from a transmitter 21 having a light emitting diode provided in the rotating frame 13. It is transmitted to the receiver 22 having a diode and transferred to the console device 40. The method of transmitting the detection data from the rotating frame 13 to the non-rotating portion of the gantry device 10 is not limited to optical communication, and other non-contact type data transmission methods may be used.

The control device 15 has a processing circuit having a CPU and the like, and a drive mechanism such as a motor and an actuator. The control device 15 has a function of receiving an input signal from the input interface 43 attached to the console device 40 or the input interface attached to the gantry device 10 and controlling the operation of the gantry device 10 and the sleeper device 30. Further, the control device 15 controls to rotate the rotating frame 13 in response to the input signal, and controls to operate the gantry device 10 and the sleeper device 30.

For example, in the control device 15, the control device 15 rotates the rotating frame 13 around an axis parallel to the X-axis direction based on the tilt angle (tilt angle) information input by the input interface attached to the gantry device 10. By doing so, the gantry device 10 is tilted.

The sleeper device 30 is a device for placing and moving the subject P to be scanned, and includes a base 31, a sleeper drive device 32, a top plate 33, and a support frame 34. The base 31 is a housing that supports the support frame 34 so as to be movable in the vertical direction. The sleeper drive device 32 is a motor or an actuator that moves the top plate 33 on which the subject P is placed in the long axis direction (Z-axis direction in FIG. 1). The top plate 33 provided on the upper surface of the support frame 34 is a plate on which the subject P is placed. In addition to the top plate 33, the sleeper drive device 32 may move the support frame 34 in the long axis direction of the top plate 33.

The sleeper drive device 32 moves the base 31 in the vertical direction according to the control signal from the control device 15. The sleeper drive device 32 moves the top plate 33 in the long axis direction according to the control signal from the control device 15.

The console device 40 is a device that accepts the operation of the X-ray CT device 1 by the user and reconstructs the X-ray CT image data from the detection data collected by the gantry device 10. The console device 40 includes a memory 41, a display 42, an input interface 43, and a processing circuit 45.

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, projection data and reconstructed image data. The memory 41 stores the scan data transferred from the DAS 18. The memory 41 is an example of a storage unit.

Further, the memory 41 includes an operation control function 45a, a preprocessing function 45b, a reconstruction processing function 45c, a planning function 45d, a scanning function 45e, a status notification function 45f, a free space calculation function 45g, a free space notification function 45h, and an alternative plan, which will be described later. It stores a dedicated program for realizing the output function 45i, the saveability notification function 45j, the transfer time notification function 45k, and the data identification function 45l.

The display 42 is a monitor referred to by the user and displays various information. For example, the display 42 outputs a medical image (CT image) generated by the processing circuit 45, a GUI (Graphical User Interface) for receiving various operations from the user, and the like. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display.

The input interface 43 receives various input operations from the user, converts the received input operations into electric signals, and outputs the received input operations to the processing circuit 45. For example, the input interface 43 receives from the user a collection condition for collecting projection data, a reconstruction condition for reconstructing a CT image, an image processing condition for generating a post-processed image from a CT image, and the like. Further, for example, the input interface 43 is realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, or the like.

The processing circuit 45 controls the operation of the entire X-ray CT apparatus 1. The processing circuit 45 may include, for example, an operation control function 45a, a preprocessing function 45b, a reconstruction processing function 45c, a planning function 45d, a scanning function 45e, a status notification function 45f, a free space calculation function 45g, a free space notification function 45h, and an alternative output. It has a function 45i, a storage availability notification function 45j, a transfer time notification function 45k, and a data identification function 45l. In the embodiment, the component operation control function 45a, preprocessing function 45b, reconstruction processing function 45c, planning function 45d, scan function 45e, status notification function 45f, free space calculation function 45g, free space notification function 45h, alternative. Each processing function performed by the draft output function 45i, the save availability notification function 45j, the transfer time notification function 45k, and the data identification function 45l is stored in the memory 41 in the form of a program that can be executed by a computer. The processing circuit 45 is a processor that realizes a function corresponding to each program by reading a program from the memory 41 and executing the program. In other words, the processing circuit 45 in the state where each program is read out has each function shown in the processing circuit 45 of FIG.

In FIG. 1, a single processor has an operation control function 45a, a preprocessing function 45b, a reconstruction processing function 45c, a planning function 45d, a scanning function 45e, a status notification function 45f, a free capacity calculation function 45g, and a free capacity. Although it has been described as realizing the notification function 45h, the alternative output function 45i, the save availability notification function 45j, the transfer time notification function 45k, and the data identification function 45l, the processing circuit 45 is configured by combining a plurality of independent processors. , The function may be realized by each processor executing a program. Further, in FIG. 1, a single storage circuit such as a memory 42 has been described as storing a program corresponding to each processing function. However, a plurality of storage circuits are distributed and arranged, and the processing circuit 45 is arranged. The configuration may be such that the corresponding program is read from an individual storage circuit.

The word "processor" used in the above description is, for example, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit), an application specific integrated circuit (ASIC), or a programmable logic device (for example, simple). It means a circuit such as a programmable logic device (Simple Programmable Logic Device: SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). The processor realizes the function by reading and executing the program stored in the memory 41. Instead of storing the program in the memory 41, the program may be directly incorporated in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit.

The operation control function 45a controls various functions of the processing circuit 45 based on an input operation received from the user via the input interface 43. For example, the operation control function 45a receives input of user information (for example, user ID or the like) for login, subject information, or the like via the input interface 43. Further, the operation control function 45a receives an input of an imaging protocol which is a scan content to be executed for the subject P. The operation control function 45a is an example of an input unit. Further, the processing circuit 45 controls the positioning image pickup, the main image pickup, and the like by the operation control function 45a.

The preprocessing function 45b generates data obtained by subjecting the detection data output from the DAS 18 to preprocessing such as logarithmic conversion processing, offset processing, sensitivity correction processing between channels, and beam hardening correction. The data before preprocessing (detection data) and the data after preprocessing may be collectively referred to as projection data.

The reconstruction processing function 45c performs reconstruction processing using a filter correction back projection method, a successive approximation reconstruction method, etc. on the projection data generated by the preprocessing function 45b according to the reconstruction conditions to obtain CT image data. Generate.

The reconstruction processing function 45c converts the reconstructed CT image data into tomographic image data or three-dimensional image data of an arbitrary cross section by a known method based on an input operation received from the user via the input interface 43. ..

The planning function 45d generates a scan plan and a transfer plan. The transfer plan is information showing a procedure for transferring the scan data acquired by the scan shown in the scan plan. That is, the transfer plan indicates the order in which the scan data is transferred and the trigger for transferring each scan data.

More specifically, the planning function 45d generates a scan plan based on the imaging protocol and information about the remaining amount of memory 183 of the DAS 18 before performing the scan indicated in the scan plan. Specifically, the planning function 45d acquires information on the remaining amount of the memory 183 before executing the scan indicated in the scan plan. For example, the planning function 45d may be acquired by storing information regarding the remaining amount of the memory 183 acquired by the free space notification function 45h at the time of the previous scan, or the free space calculation function 45g or the like each time. It may be acquired from the free space monitoring function 184e.

The planning function 45d generates a scan plan indicating the scanning procedure instructed by the imaging protocol. The planning function 45d is an example of a plan generation unit. However, the memory 183 of the DAS 18 (see FIG. 3) overflows when an amount of scan data exceeding the free space is acquired. Therefore, the planning function 45d determines the timing at which the scan is executed so that the memory 183 does not overflow. Then, the planning function 45d generates a scan specified by the imaging protocol and a scan plan showing a trigger to execute the scan.

Further, the planning function 45d generates a scan plan for executing the scan indicated by the image pickup protocol to be interrupted first when the interrupt of the scan plan is specified. For example, scan plan interrupts are specified in the event of an emergency.

Further, the planning function 45d generates a transfer plan indicating a plan for transferring the scan data stored in the memory 183 to the console device 40. The planning function 45d is an example of a generation unit. More specifically, the planning function 45d indicates the transfer timing based on the scan plan, the information regarding the remaining amount of the memory 183, and the transfer rate of the scan data from the memory 183 of the DAS 18 to the memory 41 of the console device 40. Generate a transfer plan.

The planning function 45d basically generates a transfer plan for transferring scan data to the console device 40 in the order of scanning. However, if the scan data is transferred in the scan order, the user may have to wait. In such a case, the planning function 45d generates a transfer plan for transferring scan data in an order different from the scan order shown in the scan plan. For example, in the case of transmitting scan data with a small amount of data next to scan data with a large amount of data, if the scan data with a large amount of data cannot be transferred at the next transfer time, the planning function 45d has a small amount of data. Generate a transfer plan to transfer the scan data first.

Further, the planning function 45d changes the order of not only the scan data in the same scan plan but also the scan data of different scan plans. That is, the planning function 45d is a scan plan executed later on the condition that the amount of data of the scan data acquired by the scan plan executed later is smaller than the free space of the memory 183 of the DAS 18 among the plurality of scan plans. After transferring the scan data acquired by, generate a transfer plan to transfer the scan data of the previously executed scan plan. As a result, if it takes a long time to transfer the scan data of the scan plan executed earlier, the planning function 45d waits for the user of the scan plan executed later by transferring the scan data of the scan plan executed later first. You can save time.

Further, when the interrupt of the scan plan is specified, the planning function 45d generates the transfer plan again including the image pickup protocol to be interrupted. For example, the planning function 45d generates a transfer plan that resumes the transfer of the scan data after the transfer of the scan data by the interrupt target scan plan is completed.

Here, the scan plan and the transfer plan generated by the planning function 45d will be described with an example. FIG. 2 is a timing chart showing an example of a scan plan and a transfer plan. The scan plan shown in FIG. 2 shows that after the scan plan A that executes the seven scans specified by the imaging protocol, the scan plan B that executes one scan specified by the imaging protocol is executed. Further, in the transfer plan shown in FIG. 2, the order of the first scan data, the second scan data, and the third scan data of the scan plan A is triggered by the completion of the third scan of the scan plan A. Indicates that the data will be transferred with. Further, the transfer plan shown in FIG. 2 indicates that the fifth scan data is transferred with the completion of the sixth scan of the scan plan A as a trigger.

Further, the transfer plan shown in FIG. 2 indicates that the fourth scan data and the sixth scan data are transferred with the completion of the seventh scan of the scan plan A as a trigger. As described above, the transfer plan shown in FIG. 2 indicates that the fifth scan data of the scan plan A is transferred and then the fourth scan data is transferred. This is because the fourth scan has a long scan time and a large amount of scan data. Therefore, the X-ray CT apparatus 1 cannot complete the transfer of the fourth scan data in the time between the sixth scan and the seventh scan. Therefore, the planning function 45d improves the efficiency of data transfer by transferring the fifth scan data. That is, the planning function 45d reduces the amount of data that must be transferred after the seventh scan.

Further, the transfer plan shown in FIG. 2 triggers the completion of the first scan of the scan plan B, transfers the first scan data of the scan plan B, and then transfers the seventh scan data of the scan plan A. I'm transferring. This is because the seventh scan of the scan plan A has a long scan time and a large amount of scan data. Therefore, if the first scan data of the scan plan B is transferred after the seventh scan data of the scan plan A is transferred, the user can take a long time even though the amount of data of the subject P of the scan plan B is small. You will have to wait. Therefore, the planning function 45d reduces the waiting time of the user by transferring the first scan data of the scan plan B first.

The scan function 45e instructs the execution of the scan of the subject P based on the scan plan. More specifically, the scan function 45e instructs the gantry device 10 to perform a scan of the content indicated in the scan plan based on the trigger indicated in the scan plan. As a result, the DAS 18 performs the collection of scan data.

The status notification function 45f notifies DAS18 of the scan status. That is, the status notification function 45f notifies the start of scanning and the end of scanning. Further, the status notification function 45f notifies the scan plan and the transfer plan generated by the planning function 45d. As a result, by counting the number of scans being executed, the DAS 18 can grasp which scan plan and which scan data is being collected. In addition, the DAS18 can transfer scan data based on the trigger indicated in the transfer plan.

Further, the status notification function 45f may change to a scan plan and notify DAS18 of which scan of which scan plan the scan is being executed. With this notification, the DAS18 can identify which scan plan and which scan. Further, the status notification function 45f may change to a transfer plan and notify DAS18 of which scan of which scan plan to transfer. As a result, the DAS 18 can transfer the specified scan data at the transfer timing indicated in the transfer plan.

Further, the status notification function 45f may notify the DAS 18 of the interruption of the transfer of the scan data currently being transferred when the interrupt of the scan plan is specified. As a result, the DAS 18 can first transfer the scan data according to the scan plan to be interrupted.

The free space calculation function 45g calculates the remaining amount of scan data that can be stored in the memory 183 of the DAS 18 based on the scan plan and the transfer plan. Here, the scan plan shows the procedure of scanning to be performed on the subject P. In other words, the scan plan indicates the content of the scan to be executed for the subject P and the timing at which the scan data is stored in the memory 183 of the DAS 18. Therefore, the free space calculation function 45g calculates the amount of data acquired when the scan indicated by the scan plan is executed. The free space calculation function 45g is an example of a calculation unit.

Further, the transfer plan indicates the timing of transferring the scan data from the memory 183 of the DAS 18. In other words, the transfer plan indicates when the scan data is read from the memory 183 of the DAS18. Therefore, the free space calculation function 45g calculates the remaining amount that can store the scan data of the memory 183 at each timing.

The free space calculation function 45g calculates the remaining amount that can be stored in the memory 41 by subtracting the amount of stored data from the total capacity that can store the scan data in the memory 183 of the DAS18. can do. Then, the free space calculation function 45g acquires the information on the remaining amount of the memory 41 before executing the scan shown in the scan plan by calculating the remaining amount before executing the scan shown in the scan plan. can do.

The free space notification function 45h acquires information on the remaining amount of the memory 183 of the DAS 18 before executing the scan indicated in the scan plan. Then, the free space notification function 45h notifies the information regarding the remaining amount of the memory 183. The free space notification function 45h is an example of an acquisition unit and a notification unit.

For example, the free space notification function 45h notifies information about the remaining amount of the memory 183 based on the calculation results of the scan plan and the respective transfer timings of the scan data. More specifically, the free space notification function 45h acquires the calculation result calculated by the free space calculation function 45g. As a result, the free space notification function 45h notifies the information regarding the remaining amount of the memory 183.

Further, the free space notification function 45h is not limited to the calculation, and may acquire information on the remaining amount of the memory 183 based on the monitoring result of the memory 183. For example, the free space notification function 45h notifies information regarding the remaining amount of the memory 183 based on the monitoring result acquired by the free space monitoring function 184e (see FIG. 3) of the DAS 18. More specifically, the free space notification function 45h acquires information on the remaining amount of the memory 183 from the free space monitoring function 184e of the DAS 18. Then, the free space notification function 45h notifies the information regarding the remaining amount of the acquired memory 183.

The alternative output function 45i is an alternative scan plan in which the amount of data that can be stored in the memory 183 is sufficient, provided that the remaining amount of the memory 183 of the DAS 18 becomes insufficient when the scan indicated in the scan plan is executed. Is output. The alternative output function 45i is an example of an output unit. That is, the alternative output function 45i outputs an alternative scan plan when it is determined by the free space notification function 45h that the free space of the memory 183 is insufficient.

For example, the alternative output function 45i outputs an alternative that reduces the amount of data acquired by the scan shown in the scan plan. Specifically, the alternative output function 45i includes a slice thickness, a scan range in the body axis direction, a View Rate indicating the ratio of the projection position per rotation of the X-ray detector 12, and a FOV indicating the scan range in the channel direction (FOV). Output alternatives with changed settings such as Field of View). The alternative output function 45i is an example of these settings, and may output alternatives with other settings changed. For example, when the X-ray CT apparatus 1 is of a PC (Photon Counting) method, the alternative output function 45i may output an alternative with a changed number of energy bins. As a result, the amount of data acquired by the DAS 18 is reduced, so that the alternative output function 45i can prevent the memory 183 of the DAS 18 from running out of free space.

Alternatively, the alternative output function 45i outputs an alternative that lengthens the time interval between scans indicated in the scan plan. This allows the DAS 18 to transfer more scan data to the console device 40 by the time the next scan is performed. Therefore, the alternative output function 45i can prevent the memory 183 of the DAS 18 from running out of free space.

Further, the alternative output function 45i may output an alternative that reduces the amount of data acquired by scanning and lengthens the time interval between scans. The X-ray CT apparatus 1 can execute the next scan after transferring more scan data by increasing the time interval of each scan. Therefore, the X-ray CT apparatus 1 can execute the scan without causing an overflow even if the free space of the memory 183 is small. The output method of the alternative output function 45i is not limited. For example, the alternative output function 45i may be output by displaying it on the display 42 of the console device 40, may be output by voice or the like, may be output by printing, or may be output via a network. It may be output by transmitting to the connected information processing apparatus.

The saveability notification function 45j notifies that the memory 183 of the DAS 18 exceeds the amount of data that can be saved when the scan indicated by the scan plan is executed. The save availability notification function 45j is an example of a notification unit. More specifically, the save availability notification function 45j is based on the amount of scan data acquired when the scan indicated by the scan plan is executed and the information regarding the remaining amount of the memory 183 acquired by the free space notification function 45h. , It is determined whether or not the memory 183 exceeds the amount of data that can be stored. Then, the saveability notification function 45j notifies that the memory 183 exceeds the amount of data that can be saved when the memory 183 exceeds the amount of data that can be saved. The notification method of the save availability notification function 45j is not limited. For example, the save availability notification function 45j may be notified by displaying it on the display 42 of the console device 40, may be notified by voice or the like, or may be transmitted to an information processing device connected via a network. It may be notified by.

The transfer time notification function 45k transfers scan data based on the amount of data acquired when the scan indicated by the scan plan is executed and the data transfer speed from the memory 183 of the DAS 18 to the memory 41 of the console device 40. Notify the time. The transfer time notification function 45k is an example of a time notification unit. Here, the data transfer speed is determined by the specifications of the interface of the DAS 18, the communication line connecting the DAS 18 and the console device 40, the interface of the console device 40, and the like. The transfer time notification function 45k calculates the transfer time by multiplying the amount of scan data acquired when the scan indicated by the scan plan is executed by the transfer speed. As a result, the transfer time notification function 45k notifies the transfer time of the scan data acquired when the scan indicated by the scan plan is executed.

Further, the transfer time notification function 45k may notify the remaining time until the transfer is completed by subtracting the elapsed time from the start of the transfer from the calculated transfer time. The notification method of the transfer time notification function 45k is not limited. For example, the transfer time notification function 45k may be notified by displaying it on the display 42 of the console device 40, may be notified by voice or the like, or may be transmitted to an information processing device connected via a network. It may be notified by.

The data specifying function 45l specifies the affiliation of the data stored in the memory 41. The data specifying function 45l is an example of a specific unit. More specifically, the data identification function 45l is a scan in which the data transferred from the memory 183 of the DAS 18 is acquired based on the first identifier given to each scan in the scan plan composed of a plurality of scans. To identify. The first identifier is identification information for identifying scan data. That is, the data specifying function 45l identifies the scan data acquired by which scan based on the first identifier associated with the scan data.

Further, the data specifying function 45l identifies a scan plan including a scan in which the data transferred from the memory 183 of the DAS 18 is acquired based on the second identifier. The second identifier is identification information for identifying the scan plan. That is, the data specifying function 45l identifies the scan data acquired by the scan included in which scan plan based on the second identifier associated with the scan data. Thereby, the reconstruction processing function 45c can specify the scan data acquired by the same scan plan and specify the order in which the scan data are acquired in the scan plan.

Next, the details of DAS 18 will be described. FIG. 3 is a block diagram showing an example of the configuration of DAS 18 according to the first embodiment.

The DAS 18 includes an amplifier 181, an A / D converter 182, a memory 183, and a processing circuit 184.

The amplifier 181 performs amplification processing on the electric signal output from each X-ray detection element of the X-ray detector 12. As a result, the amplifier 181 amplifies the electric signal.

The A / D converter 182 converts the electric signal amplified by the amplifier 181 into a digital signal. For example, the A / D converter 182 acquires detection data by executing an A / D conversion process on an electric signal output from each X-ray detection element of the X-ray detector 12. Then, the A / D converter 182 stores the acquired detection data in the memory 183.

The memory 183 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, a hard disk, an optical disk, or the like. The memory 183 stores the detection data. That is, the memory 183 temporarily stores the data detected by the X-ray detector 12. Memory 183 is an example of a buffer.

The processing circuit 184 controls the operation of the entire DAS18. The processing circuit 184 has, for example, a plan acquisition function 184a, a grant function 184b, a transfer timing determination function 184c, a transfer function 184d, and a free space monitoring function 184e. In the embodiment, each processing function performed by the plan acquisition function 184a, the grant function 184b, the transfer timing determination function 184c, the transfer function 184d, and the free space monitoring function 184e, which are the components, is a form of a program that can be executed by a computer. Is stored in the memory 183. The processing circuit 184 is a processor that realizes a function corresponding to each program by reading a program from the memory 183 and executing the program. In other words, the processing circuit 184 in the state where each program is read out has each function shown in the processing circuit 184 of FIG.

Although it has been described in FIG. 3 that the plan acquisition function 184a, the grant function 184b, the transfer timing determination function 184c, the transfer function 184d, and the free space monitoring function 184e are realized by a single processor, a plurality of independent functions are realized. The processing circuit 184 may be configured by combining the processors, and the functions may be realized by each processor executing the program. Further, in FIG. 3, a single storage circuit such as a memory 183 has been described as storing a program corresponding to each processing function. However, a plurality of storage circuits are distributed and arranged, and the processing circuit 184 The configuration may be such that the corresponding program is read from an individual storage circuit.

The term "processor" used in the above description means, for example, a circuit such as a CPU, a GPU, or an integrated circuit for a specific application, a programmable logic device, a composite programmable logic device, and a field programmable gate array. The processor realizes the function by reading and executing the program stored in the memory 183. Instead of storing the program in the memory 183, the program may be directly incorporated in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit.

The plan acquisition function 184a acquires scan and transfer instructions from the console device 40. For example, the plan acquisition function 184a acquires a scan plan and a transfer plan. As a result, the plan acquisition function 184a acquires a series of instructions shown in the scan plan and the transfer plan.

Alternatively, the plan acquisition function 184a may acquire the instructions shown in the scan plan and the transfer plan each time. For example, the plan acquisition function 184a acquires information indicating the first identifier and the second identifier indicating the transfer target when the trigger indicated in the transfer plan occurs. Thereby, the plan acquisition function 184a can specify the transfer timing and the transfer target.

Further, the plan acquisition function 184a acquires a notification indicating the interruption of the transfer from the console device 40. As a result, the plan acquisition function 184a grasps that the scan plan interrupt has occurred.

The assigning function 184b assigns a first identifier for identifying the scan to the scan data acquired by each scan in the scan plan. Further, the grant function 184b assigns a second identifier for identifying the scan plan to the scan data acquired by each scan in the scan plan. More specifically, the grant function 184b assigns a first identifier based on the scan plan acquired by the plan acquisition function 184a. For example, the grant function 184b grants the order of each scan in the scan plan as a first identifier. The first identifier is not limited to the order of each scan, and other information may be added. In this way, by assigning the first identifier, the console device 40 can identify which scan the scan data was acquired without transmitting the scan data in the order of the scan plan. can.

Similarly, the grant function 184b assigns a second identifier based on the scan plan acquired by the plan acquisition function 184a. For example, the granting function 184b grants information such as identification information for identifying the subject P targeted by the scan plan and identification information for identifying the test performed by the scan plan as the second identifier. .. In this way, by assigning the second identifier, the console device 40 can identify which scan plan the scan data is, even if the scan data is not transmitted in the order of the scan plans.

The transfer timing determination function 184c determines the transfer timing of the scan data from the memory 183 of the DAS 18 to the memory 41 of the console device 40 based on the scan plan and the information regarding the remaining amount of the memory 183. The transfer timing determination function 184c is an example of a determination unit. Here, the planning function 45d generates a generation plan based on the scan plan, the information regarding the remaining amount of the memory 183, and the transfer rate of the scan data from the memory 183 of the DAS 18 to the memory 41 of the console device 40. The transfer timing determination function 184c determines the transfer timing based on the transfer plan generated by the planning function 45d. That is, the transfer timing determination function 184c determines to transfer the scan data at the transfer timing indicated in the transfer plan.

Alternatively, the transfer timing determination function 184c acquires a transfer request from the console device 40 each time the scan data is transferred. Then, the transfer timing determination function 184c sets the timing specified by the transfer request as the transfer timing of the scan data. As a result, the transfer timing determination function 184c determines the transfer timing of the scan data.

Further, the transfer timing determination function 184c determines to restart the transfer after the data acquired by the scan plan is transferred when the interrupt of the scan plan is instructed. As a result, the transfer timing determination function 184c preferentially transfers the scan data to be interrupted.

The transfer function 184d transfers the scan data at the transfer timing determined by the transfer timing determination function 184c. More specifically, the transfer function 184d causes the transmitter 21 to transmit the first identifier, the second identifier, and the scan data in association with each other.

Here, the plan acquisition function 184a may instruct the console device 40 to suspend the transfer of scan data when an interrupt of the scan plan is specified. When the transfer function 184d receives the notification for interrupting the transfer of the scan data, the transfer function 184d notifies the console device 40 of the first identifier and the second identifier indicating the scan data for which the transfer has been completed. Thereby, the console device 40 can specify from which scan data the transfer should be restarted. For example, if the transfer function 184d may interrupt the transfer in the middle of the scan data, the console device 40 cannot determine whether the transfer was interrupted in the middle of the transferred scan data or whether the entire transfer was performed. Even in such a case, the console device 40 can specify from which scan data the transfer should be restarted by notifying the scan data that the transfer is completed.

The free space monitoring function 184e monitors the free space of the memory 183. More specifically, the free space monitoring function 184e monitors the amount of data written to the memory 183 and the amount of data read from the memory 183. As a result, the free space monitoring function 184e measures the free space in the storage area in which the scan data in the memory 183 can be stored. Then, the free space monitoring function 184e notifies the console device 40 of the measurement result as information regarding the remaining amount of the memory 183.

Next, the transfer process executed by the X-ray CT apparatus 1 will be described. FIG. 3 is a flowchart showing an example of a transfer process executed by the X-ray CT apparatus 1 according to the first embodiment.

The operation control function 45a accepts the input of the image pickup protocol (step S1).

The planning function 45d generates a scan plan and a transfer plan based on the received imaging protocol (step S2).

The free space calculation function 45g calculates the amount of scan data acquired by the generated scan plan (step S3).

The free space notification function 45h acquires information on the remaining amount of the memory 183 of the DAS 18 from the free space calculation function 45g (step S4). Alternatively, information regarding the remaining amount of the memory 183 is acquired from the free space monitoring function 184e.

The free space notification function 45h notifies the remaining amount of the memory 183 based on the information regarding the remaining amount of the memory 183 (step S5). The free space notification function 45h is not limited to step S5, and may notify the remaining amount of the memory 183 in other steps.

The saveability notification function 45j determines whether or not the scan data can be saved in the memory 183 based on the information regarding the remaining amount of the memory 183 and the data amount of the scan data acquired by the scan plan (step S6). .. That is, the save availability notification function 45j determines whether or not the free space of the memory 183 is insufficient.

When the scan data cannot be saved due to insufficient free space in the memory 183 (step S6; No), the save availability notification function 45j can save the memory 183 when the scan indicated by the scan plan is executed. Notify that the amount of data exceeds a large amount (step S7).

The alternative output function 45i outputs an alternative scan plan that is the amount of data that can be stored in the memory 183 (step S8). Then, the motion control function 45a proceeds to step S1 and accepts the input of the imaging protocol shown in the alternative.

When the scan data can be stored in the memory 183 (step S6; Yes), the transfer time notification function 45k determines the data amount of the scan data and the transfer speed of the scan data from the memory 183 of the DAS 18 to the memory 41 of the console device 40. Based on the above, the transfer time of the scan data is notified (step S9).

The transfer function 184d determines whether or not it is time to transfer the scan data scanned by the scan plan (step S10). That is, the transfer function 184d determines whether or not the scan data transfer request has been received.

When the transfer timing has not been reached (step S10; No), the transfer function 184d waits for the transfer of scan data. When the transfer timing is reached (step S10; Yes), the transfer function 184d associates and transfers the scan data, the first identifier, and the second identifier (step S11).

The transfer function 184d determines whether or not the transfer indicated by the transfer plan is completed (step S12).

When the transfer of the scan data is not completed (step S12; No), the operation control function 45a determines whether or not the interrupt of the scan plan is instructed (step S13). That is, the operation control function 45a determines whether or not the imaging protocol instructing the interrupt of the scan plan has been input.

When the interrupt of the scan plan is not instructed (step S13; No), the X-ray CT apparatus 1 proceeds to step S9 to assign the first identifier and the second identifier to the scan data and transfer the scan data. And continue.

When the interrupt of the scan plan is instructed (step S13; Yes), the planning function 45d proceeds to step S2 to generate a scan plan and a transfer plan including the image pickup protocol to be interrupted. As a result, the X-ray CT apparatus 1 executes the remaining processing after executing the instructed interrupt.

When the transfer of the scan data is completed in step S5 (step S12; Yes), the X-ray CT apparatus 1 ends the transfer process.

As described above, the X-ray CT apparatus 1 according to the first embodiment includes a memory 183 that temporarily stores the data detected by the X-ray detector 12. Further, the free space notification function 45h of the console device 40 acquires information on the remaining amount of the memory 183 of the DAS 18 before executing the scan indicated in the scan plan. The transfer timing determination function 184c determines the transfer timing of the scan data according to the transfer plan generated based on the scan plan and the information regarding the remaining amount of the memory 183. In this way, the X-ray CT apparatus 1 determines the transfer timing of the scan data based on the scan plan and the free capacity of the memory 183. In other words, the X-ray CT apparatus 1 transfers the scan data before the buffer overflows, depending on the plans for future scans. That is, the X-ray CT apparatus 1 can transfer scan data without causing an overflow even if it does not have a buffer having a maximum capacity expected. Therefore, the X-ray CT apparatus 1 can scan the subject P while suppressing the storage capacity of the buffer from becoming large.

(Second embodiment)
In the X-ray CT apparatus 1 according to the first embodiment, it has been explained that the DAS 18 has a buffer for temporarily storing the scan data detected by the X-ray detector 12. In the X-ray CT apparatus 1a according to the second embodiment, the relay apparatus 50 is provided with a buffer instead of the DAS18.

FIG. 5 is a block diagram showing an example of the configuration of the X-ray CT apparatus 1a according to the second embodiment. The relay device 50 is installed on the console device 40 side of the receiver 22 provided in the non-rotating portion of the gantry device 10 such as a fixed frame. As a result, the X-ray CT device 1a can efficiently transfer data even when the transfer speed on the console device 40 side is slower than that of the receiver 22.

Next, the details of the relay device 50 will be described. FIG. 6 is a block diagram showing an example of the configuration of the relay device 50 according to the second embodiment.

The relay device 50 includes a memory 51 and a processing circuit 52.

The memory 51 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, a hard disk, an optical disk, or the like. The memory 51 stores the detection data. That is, the memory 51 temporarily stores the data detected by the X-ray detector 12.

The processing circuit 52 controls the operation of the entire relay device 50. In the processing circuit 52, for example, each processing function performed by the plan acquisition function 52a, the grant function 52b, the transfer timing determination function 52c, the transfer function 52d, and the free space monitoring function 52e is in the form of a program that can be executed by a computer. It is stored in the memory 51. The processing circuit 52 is a processor that realizes a function corresponding to each program by reading a program from the memory 51 and executing the program. In other words, the processing circuit 52 in the state where each program is read out has each function shown in the processing circuit 52 of FIG.

Although it has been described in FIG. 6 that the plan acquisition function 52a, the grant function 52b, the transfer timing determination function 52c, the transfer function 52d, and the free space monitoring function 52e are realized by a single processor, a plurality of independent functions are realized. The processing circuit 52 may be configured by combining the processors, and the functions may be realized by each processor executing a program. Further, in FIG. 6, a single storage circuit such as a memory 51 has been described as storing a program corresponding to each processing function. However, a plurality of storage circuits are distributed and arranged, and the processing circuit 52 is arranged. The configuration may be such that the corresponding program is read from an individual storage circuit.

The term "processor" used in the above description means, for example, a circuit such as a CPU, a GPU, or an integrated circuit for a specific application, a programmable logic device, a composite programmable logic device, and a field programmable gate array. The processor realizes the function by reading and executing the program stored in the memory 51. Instead of storing the program in the memory 51, the program may be directly incorporated in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit.

The plan acquisition function 52a has the same function as the plan acquisition function 184a of the DAS18.

The granting function 52b has the same function as the granting function 184b of DAS18.

The transfer timing determination function 52c has the same function as the transfer timing determination function 184c of the DAS18.

The transfer function 52d has the same function as the transfer function 184d of the DAS18.

The free space monitoring function 52e has the same function as the free space monitoring function 184e of the DAS18.

As described above, the X-ray CT apparatus 1a according to the second embodiment includes a memory 51 for temporarily storing the data detected by the X-ray detector 12. Further, the free space notification function 45h of the console device 40 acquires information regarding the remaining amount of the memory 51 of the relay device 50 before executing the scan indicated in the scan plan. The transfer timing determination function 184c determines the transfer timing of the scan data according to the transfer plan generated based on the scan plan and the information regarding the remaining amount of the memory 51. In other words, the X-ray CT apparatus 1a transfers the scan data before the buffer overflows, depending on the plans for future scans. Therefore, the X-ray CT apparatus 1a can scan the subject P while suppressing the storage capacity of the buffer from becoming large.

(Modification 1)
In the second embodiment, the case where the relay device 50 includes a buffer for temporarily storing the scan data detected by the X-ray detector 12 instead of the DAS 18 has been described. The buffer for temporarily storing the scan data detected by the X-ray detector 12 may be installed in both the DAS 18 and the relay device 50.

For example, when the transfer speed after the X-ray detector 12 is slower than the acquisition speed of the scan data, the X-ray CT apparatus 1b can efficiently transfer the scan data by providing a buffer in the DAS 18. Further, when the transfer speed from the receiver 22 to the console device 40 is slower than the transfer speed from the DAS 18 to the receiver 22, the X-ray CT device 1b provides a buffer in the DAS 18 to efficiently transmit scan data. Can be transferred.

(Modification 2)
Further, in the above embodiment, it is described that the DAS 18 transfers the scan data to the console device 40 when the scan data is not acquired. However, the DAS 18 may transfer the scan data to the console device 40 when the scan data is acquired.

Although some embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, and combinations of embodiments can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

Regarding the above embodiments, the following appendices are disclosed as one aspect and selective features of the invention.
(Appendix 1)
A buffer that temporarily stores the data detected by the X-ray detector, and
An input unit that accepts the input of the imaging protocol and
A plan generator that generates a scan plan indicating the scanning procedure instructed by the imaging protocol, and a plan generator.
An excess notification unit that notifies that the buffer exceeds the amount of data that can be stored when the scan indicated by the scan plan is executed.
X-ray CT apparatus.
(Appendix 2)
A buffer that temporarily stores the data detected by the X-ray detector, and
An input unit that accepts the input of the imaging protocol and
A plan generator that generates a scan plan indicating the scanning procedure instructed by the imaging protocol, and a plan generator.
A calculation unit that calculates the amount of data acquired when the scan indicated by the scan plan is executed, and
A time notification unit that notifies the transfer time of the data based on the amount of the data and the transfer rate of the data from the buffer to the storage unit.
X-ray CT apparatus.

1,1a, 1b X-ray CT equipment 10 Standing equipment 18 DAS
21 Transmitter 22 Receiver 30 Sleeper device 40 Console device 50 Relay device 41, 183, 51 Memory 45a Operation control function 45b Preprocessing function 45c Reconstruction processing function 45d Planning function 45e Scan function 45f Status notification function 45g Free space calculation function 45h Free space notification function 45i Alternative output function 45j Saveability notification function 45k Transfer time notification function 45l Data identification function 184a, 52a Plan acquisition function 184b, 52b Grant function 184c, 52c Transfer timing determination function 184d, 52d Transfer function 184e, 52e Free Capacity monitoring function

Claims (12)

A buffer that temporarily stores the data detected by the X-ray detector, and
An acquisition unit that acquires information about the remaining amount of the buffer before executing the scan indicated in the scan plan, and
A determination unit that determines the timing of data transfer from the buffer to the storage unit based on the scan plan and information regarding the remaining amount of the buffer.
X-ray CT apparatus. It further includes an output unit that outputs an alternative to the scan plan based on the remaining amount of the buffer when the scan shown in the scan plan is executed and the amount of data that can be stored in the buffer.
The X-ray CT apparatus according to claim 1. The output unit outputs the alternative to reduce the amount of data acquired by the scan indicated in the scan plan.
The X-ray CT apparatus according to claim 2. The output unit outputs the alternative to increase the time interval between scans indicated in the scan plan.
The X-ray CT apparatus according to claim 2. Further provided with a notification unit for notifying information regarding the remaining amount of the buffer.
The X-ray CT apparatus according to any one of claims 1 to 4. The notification unit notifies information about the remaining amount of the buffer based on the monitoring result of the amount of data written to the buffer and the amount of data read from the buffer.
The X-ray CT apparatus according to claim 5. The notification unit notifies information about the remaining amount of the buffer based on the calculation result of the scan plan and the transfer timing of each of the data.
The X-ray CT apparatus according to claim 5. Further including a generation unit that generates a transfer plan indicating the transfer timing based on the scan plan, information on the remaining amount of the buffer, and the transfer rate of the data from the buffer to the storage unit.
The determination unit determines the transfer timing based on the transfer plan generated by the generation unit.
The X-ray CT apparatus according to any one of claims 1 to 7. The generation unit generates the transfer plan that transfers the data in an order different from the scan order shown in the scan plan.
The X-ray CT apparatus according to claim 8. The generation unit is acquired by the scan plan executed later on the condition that the amount of data acquired by the scan plan to be executed later is smaller than the free space of the buffer among the plurality of scan plans. After transferring the transferred data, the transfer plan for transferring the data of the previously executed scan plan is generated.
The X-ray CT apparatus according to claim 9. When the interrupt of the scan plan is instructed, the determination unit determines to restart the transfer after the transfer of the data acquired by the scan plan.
The X-ray CT apparatus according to claim 9. The data detected by the X-ray detector is stored in a buffer that is temporarily stored, and then stored.
Obtain information about the remaining amount of the buffer before executing the scan indicated in the scan plan.
The timing of transferring data from the buffer to the storage unit is determined based on the scan plan and the information regarding the remaining amount of the buffer.
Data transfer methods including that.

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