Medical image diagnostic apparatus, control method, and program

Abstract

To adjust the start timing of a scan accompanying respiratory arrest on a patient-by-patient basis.SOLUTION: A medical image diagnostic apparatus according to the embodiment includes a first acquisition unit, an estimation unit, and a control unit. The first acquisition unit acquires respiration information indicating a change over time in respiration of a subject. The estimation unit estimates a wait time indicating a period from a respiratory arrest notification to the respiratory arrest on the basis of the respiration information. The control unit starts a scan of the subject when the wait time has elapsed after the respiratory arrest notification to the subject.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to a medical imaging diagnostic apparatus, a control method, and a program.

[0002] Conventionally, in a medical imaging diagnostic apparatus such as an X-ray CT (Computed Tomography) apparatus, when scanning the chest and abdomen, medical staff need to ask the patient to stop breathing in order to prevent the medical image from becoming unclear due to the movement associated with breathing.

[0003] Therefore, the medical staff starts the scan of the patient on the medical imaging diagnostic apparatus at the timing when the breathing stop is notified by voice or the like.

[0004] However, it may be difficult for the patient to stop breathing at the timing when the breathing stop is notified. In this case, since the medical imaging diagnostic apparatus has not stopped breathing, it will acquire an unclear medical image due to the movement associated with breathing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to adjust the start timing of the scan involving breathing stop according to the patient. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. It is also possible to position the problems corresponding to the respective effects of each configuration shown in the embodiments described later as other problems.

Means for Solving the Problems

[0007] The medical image diagnostic apparatus according to the embodiment includes a first acquisition unit, an estimation unit, and a control unit. The first acquisition unit acquires respiratory information indicating the temporal change of the respiration of a subject. The estimation unit estimates a standby time indicating the period from the notification of respiratory arrest to respiratory arrest based on the respiratory information. The control unit starts a scan on the subject when the standby time has elapsed since the notification of respiratory arrest to the subject.

Brief Description of Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, a medical image diagnostic apparatus, a control method, and a program according to the present embodiment will be described. In the following embodiments, parts denoted by the same reference numerals perform the same operations, and overlapping descriptions will be omitted as appropriate.

[0010] (First Embodiment) FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus 1 according to the first embodiment. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a couch device 30, and a console device 40.

[0011] Here, in FIG. 1, the rotation axis of the rotating frame 13 or the longitudinal direction of the top plate 33 of the bed device 30 in the non-tilted state is defined as the Z-axis direction. Also, the axial direction that is orthogonal to the Z-axis direction and horizontal with respect to the floor surface is defined as the X-axis direction. Further, the axial direction that is orthogonal to the Z-axis direction and the X-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. Note that FIG. 1 is drawn of the gantry device 10 from a plurality of directions for the purpose of explanation, and shows the case where the X-ray CT apparatus 1 has one gantry device 10.

[0012] The gantry device 10 includes an X-ray tube 11, an X-ray detector 12, a rotating frame 13, an X-ray high voltage device 14, a control device 15, a wedge 16, a collimator 17, and a DAS (Data Acquisition System) 18. Note that the gantry device 10 is also referred to as a gantry. Also, the gantry device 10 has an opening into which the subject P is inserted.

[0013] The X-ray tube 11 is a vacuum tube having a cathode (filament) that generates thermoelectrons and an anode (target) that generates X-rays upon receiving the collision of the thermoelectrons. The X-ray tube 11 generates X-rays to irradiate the subject P by irradiating thermoelectrons from the cathode toward the anode by applying a high voltage from the X-ray high voltage device 14. For example, the X-ray tube 11 includes a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

[0014] The X-ray detector 12 detects the X-rays that are irradiated from the X-ray tube 11 and pass through the subject P, and outputs a signal corresponding to the detected X-ray dose to the DAS 18. The X-ray detector 12 has, for example, a plurality of detector element arrays in which a plurality of detector elements are arranged in the channel direction (channel direction) along an arc centered 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 detector element arrays in which a plurality of detector elements are arranged in the channel direction are arranged in the column direction (slice direction, row direction).

[0015] For example, the X-ray detector 12 is an indirect conversion type detector having a grid, a scintillator array, and a photosensor array. The scintillator array has a plurality of scintillators. Each scintillator has a scintillator crystal that outputs light in an amount of photons corresponding to the incident X-ray dose. The grid is disposed on the X-ray incident side surface of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. Note that the grid may also be referred to as a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has a function of converting the amount of light from the scintillator into an electrical signal, and has, for example, photosensors such as photodiodes. Note that the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts the incident X-ray into an electrical signal. Also, the X-ray detector 12 may be a photon counting type X-ray detector.

[0016] The rotating frame 13 is an annular frame that oppositely supports the X-ray tube 11 and the X-ray detector 12 and rotates the X-ray tube 11 and the X-ray detector 12 by the control device 15. For example, the rotating frame 13 is a casting made of aluminum. Note that in addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 can further support an X-ray high voltage device 14, a wedge 16, a collimator 17, a DAS 18, etc. Further, the rotating frame 13 can further support various configurations not shown in FIG. 1. The various configurations supported by the rotating frame 13 will be described later. Note that the rotating frame 13 is also referred to as a rotating base, a rotating body, etc. Also, in the gantry device 10, the rotating frame 13 and the portions that rotate and move together with the rotating frame 13 are also referred to as a rotating part.

[0017] The X-ray high voltage device 14 has an electric circuit such as a transformer (transformer) and a rectifier, and includes a high voltage generator that generates a high voltage applied to the X-ray tube 11, and an X-ray control device that controls the output voltage corresponding to the X-ray generated by the X-ray tube 11. The high voltage generator may be of a transformer type or an inverter type. Note that the X-ray high voltage device 14 may be provided on the rotating frame 13 or may be provided on a fixed frame not shown.

[0018] The control device 15 includes a processing circuit having a CPU (Central Processing Unit) or the like, and a drive mechanism such as a motor and an actuator. The control device 15 receives an input signal from an input interface 43 described later and controls the operations of the gantry device 10 and the bed device 30. For example, the control device 15 controls the rotation of the rotary frame 13, the tilt of the gantry device 10, the operations of the bed device 30 and the top plate 33, etc. As an example, as control for tilting the gantry device 10, the control device 15 rotates the rotary frame 13 about an axis parallel to the X-axis direction based on the input tilt angle information. Note that the control device 15 may be provided on the gantry device 10 or may be provided on the console device 40.

[0019] The wedge 16 is a filter for adjusting the X-ray dose irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the distribution of the X-rays irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. For example, the wedge 16 is a wedge filter or a bow-tie filter, and is a filter formed by processing aluminum or the like to have a predetermined target angle and a predetermined thickness.

[0020] The collimator 17 is a lead plate or the like for narrowing down the irradiation range of the X-rays that have passed through the wedge 16, and forms a slit by combining a plurality of lead plates or the like. Note that the collimator 17 may also be referred to as an X-ray aperture. Also, in FIG. 1, the case where the wedge 16 is arranged between the X-ray tube 11 and the collimator 17 is shown, but the case where the collimator 17 is arranged between the X-ray tube 11 and the wedge 16 may also be possible. In this case, the wedge 16 transmits and attenuates the X-rays irradiated from the X-ray tube 11 and whose irradiation range is limited by the collimator 17.

[0021] DAS18 collects the X-ray signals detected by each detection element of the X-ray detector 12. For example, DAS18 has an amplifier that performs an amplification process on the electrical signals output from each detection element, and an A / D converter that converts the electrical signals into digital signals, and generates detection data.

[0022] The detection data generated by DAS18 is transmitted from a transmitter having a light-emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on a non-rotating portion (for example, a fixed frame, etc. The illustration in FIG. 1 is omitted) of the gantry device 10 by optical communication, and is transferred to the console device 40. Here, the non-rotating portion is, for example, a fixed frame that rotatably supports the rotating frame 13. Note that the method of transmitting data from the rotating frame 13 to the non-rotating portion of the gantry device 10 is not limited to optical communication, and any non-contact data transmission method may be adopted, or a contact-type data transmission method may be adopted.

[0023] The bed device 30 is a device for placing and moving the subject P to be imaged, and includes a base 31, a bed driving 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 bed driving device 32 is a driving mechanism that moves the top plate 33 on which the subject P is placed in the longitudinal direction of the top plate 33, and includes a motor, an actuator, and the like. The top plate 33 provided on the upper surface of the support frame 34 is a plate on which the subject P is placed. Note that the bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33 in addition to the top plate 33.

[0024] The subject P is equipped with the respiration sensor 20. The respiration sensor 20 is a sensor that detects the respiration state of the subject P. The respiration sensor 20 is an example of a respiration detection unit. In other words, the respiration sensor 20 is a sensor that detects how much air the subject P is inhaling. For example, the respiration sensor 20 is a sensor that detects the inflation of the lungs, i.e., the change in the height of the chest. Note that the respiration sensor 20 may be a sensor that detects the respiration state of the subject P by other methods, not limited to the change in the height of the chest.

[0025] The notification device 50 notifies various matters to the subject P and medical staff around the gantry device 10 according to the control by the console device 40. For example, the notification device 50 may be a display device arranged in the hollow where the subject P is inserted in the gantry device 10, or a projector that projects an image onto a screen arranged in the hollow where the subject P is inserted in the gantry device 10 or onto the wall surface around the hollow where the subject P is inserted, or a speaker that outputs sound to the subject P inserted into the gantry device 10, or may be realized by other devices.

[0026] Furthermore, the notification device 50 is not limited to a device that notifies the subject P inserted into the gantry device 10, and may be a display device arranged in front of the gantry device 10, or a projector that projects an image onto a screen installed in the room where the gantry device 10 is installed, or a speaker that outputs sound, or may be realized by other devices.

[0027] The console device 40 includes a memory 41, a display 42, an input interface 43, and a processing circuit 44. Although the console device 40 is described as a separate body from the gantry device 10, the gantry device 10 may include the console device 40 or a part of each component of the console device 40.

[0028] The memory 41 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, a hard disk, an optical disk, etc. The memory 41 stores, for example, projection data and CT image data. Also, for example, the memory 41 stores a program for the circuits included in the X-ray CT apparatus 1 to realize various functions. The memory 41 may be realized by a server group (cloud) connected to the X-ray CT apparatus 1 via a network.

[0029] The display 42 displays various kinds of information. For example, the display 42 displays various images generated by the processing circuit 44 or displays a GUI (Graphical User Interface) for receiving various operations from the operator. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 42 may be a desktop type or may be configured by a tablet terminal or the like capable of wireless communication with the console apparatus 40 main body. Also, the display 42 is an example of a display unit.

[0030] The input interface 43 receives various input operations from the operator, converts the received input operations into electrical signals, and outputs them to the processing circuit 44. Also, for example, the input interface 43 receives input operations from the operator such as scan conditions, reconstruction conditions when reconstructing CT image data, and image processing conditions when generating a post-processed image from CT image data.

[0031] For example, the input interface 43 can be realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch pad that performs an input operation by touching an operation surface, a touch screen in which a display screen and a touch pad are integrated, a non-contact input circuit using an optical sensor, a voice input circuit, and the like. Note that the input interface 43 may be provided in the gantry device 10. Also, the input interface 43 may be configured by a tablet terminal or the like that can communicate wirelessly with the console device 40 main body. Further, the input interface 43 is not limited to only those having physical operation components such as a mouse and a keyboard. For example, a processing circuit for an electrical signal that receives an electrical signal corresponding to an input operation from an external input device provided separately from the console device 40 and outputs this electrical signal to the processing circuit 44 is also included in the example of the input interface 43.

[0032] The processing circuit 44 controls the operation of the entire X-ray CT apparatus 1. The processing circuit 44 has, for example, a patient information acquisition function 411, a respiration information acquisition function 412, a respiration estimation function 413, a notification function 414, a display control function 415, a system control function 416, a preprocessing function 417, a reconstruction processing function 418, and a respiration information storage function 419. In the embodiment, each processing function performed by the patient information acquisition function 411, the respiration information acquisition function 412, the respiration estimation function 413, the notification function 414, the display control function 415, the system control function 416, the preprocessing function 417, the reconstruction processing function 418, and the respiration information storage function 419 is stored in the memory 41 in the form of a program executable by a computer. The processing circuit 44 is a processor that reads a program from the memory 41 and executes it to realize the functions corresponding to the respective programs. In other words, the processing circuit 44 in the state of having read each program has each function shown in the processing circuit 44 of FIG. 1.

[0033] In FIG. 1, it has been described that a single processor realizes the patient information acquisition function 411, the respiration information acquisition function 412, the respiration estimation function 413, the notification function 414, the display control function 415, the system control function 416, the preprocessing function 417, the reconstruction processing function 418, and the respiration information storage function 419. However, it is also acceptable to configure the processing circuit 44 by combining a plurality of independent processors, and each processor realizes functions by executing a program. Also, in FIG. 1, it has been described that a single storage circuit such as the memory 41 stores programs corresponding to respective processing functions. However, it is also acceptable to distribute and arrange a plurality of storage circuits, and the processing circuit 44 reads corresponding programs from individual storage circuits.

[0034] The term "processor" used in the above description means, for example, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit), or a circuit such as an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The processor realizes functions by reading and executing the program stored in the memory 41. Note that instead of storing the program in the memory 41, it may be configured to directly incorporate the program into the circuit of the processor. In this case, the processor realizes functions by reading and executing the program incorporated into the circuit.

[0035] The patient information acquisition function 411 acquires information regarding the patient who is the subject P. For example, the patient information acquisition function 411 acquires patient identification information for identifying the patient. The patient information acquisition function 411 is an example of the second acquisition unit. The patient identification information is an example of the subject identification information. For example, the patient identification information is information such as a patient code for identifying the patient or the name of the patient.

[0036] In addition, the patient information acquisition function 411 acquires patient attribute information indicating the attributes of the patient. The patient information acquisition function 411 is an example of the third acquisition unit. The patient attribute information is an example of the subject attribute information. For example, the patient attribute information is information such as age and gender. Note that the patient information acquisition function 411 may acquire both the patient identification information and the patient attribute information.

[0037] The respiration information acquisition function 412 acquires respiration information indicating the temporal change in the respiration of the subject P. The respiration information acquisition function 412 is an example of the first acquisition unit. More specifically, the respiration information acquisition function 412 generates respiration information by recording the respiration state detected by the respiration sensor 20. In other words, the respiration information acquisition function 412 generates respiration information indicating the temporal change in the chest height of the subject P detected by the respiration sensor 20.

[0038] Here, before the subject P is scanned by the X-ray CT apparatus 1, the subject P may practice breath-holding during scanning in accordance with the instructions of medical staff. For example, the respiration information acquisition function 412 generates respiration information by recording the respiration state detected by the respiration sensor 20 during the breath-holding practice.

[0039] In addition, when there is respiratory information generated in the past, the respiratory information acquisition function 412 may acquire the respiratory information generated in the past. That is, the respiratory information acquisition function 412 may acquire the respiratory information stored in a storage unit such as the memory 41 or the storage medium of another device. More specifically, the respiratory information acquisition function 412 may acquire the respiratory information specified by the patient code acquired by the patient information acquisition function 411 from a storage unit that stores one or more pieces of respiratory information. Further, the respiratory information acquisition function 412 may acquire the respiratory information specified by the patient attributes acquired by the patient information acquisition function 411 from a storage unit that stores one or more pieces of respiratory information. That is, the respiratory information acquisition function 412 may acquire the respiratory information generated during the apnea practice and one or more pieces of respiratory information acquired from the storage unit.

[0040] In addition, the respiratory information acquisition function 412 is not limited to the apnea practice, and may generate respiratory information by recording the respiratory state detected by the respiratory sensor 20 during the scan of the subject P by the X-ray CT apparatus 1. In this case, the generated respiratory information is utilized in future processing.

[0041] The respiration estimation function 413 estimates the respiration of the subject P during the scan by the X-ray CT apparatus 1 based on the respiratory information acquired by the respiratory information acquisition function 412. For example, the respiration estimation function 413 estimates a standby time indicating the period from the apnea notification to the apnea based on the respiratory information. The respiration estimation function 413 is an example of an estimation unit.

[0042] Here, FIG. 2 is a graph showing an example of the temporal change of the respiration of the subject P indicated by the respiratory information. In FIG. 2, the horizontal axis represents time, and the vertical axis represents the respiratory state, that is, the height of the chest. Also, in FIG. 2, t0 indicates the standby time, t1 indicates the apnea notification timing, t2 indicates the start timing when the subject P starts to stop breathing after receiving the apnea notification, and t3 indicates the stabilization timing when it is determined that the apnea state has stabilized.

[0043] As shown in FIG. 2, when the subject P is not particularly restricted, the height of the chest changes periodically with breathing. At t1, the notification device 50 notifies the subject P of apnea. At t2, the subject P starts apnea. However, the state of apnea of the subject P is not stable. At t3, the respiration estimation function 413 determines that the state of apnea of the subject P has stabilized. For example, when the state of apnea has continued for a specified period after the notification of apnea, the respiration estimation function 413 determines that the state of apnea of the subject P has stabilized. In other words, when the period during which the variation in chest height is less than the threshold value continues for a specified period, the respiration estimation function 413 determines that the state of apnea of the subject P has stabilized. Then, the respiration estimation function 413 estimates the period from t1 to t3 as the waiting time for the apnea of the subject P to stabilize.

[0044] Further, when a plurality of respiration information is acquired by the respiration information acquisition function 412, the respiration estimation function 413 executes the above-described processing for each piece of respiration information. Thereby, the respiration estimation function 413 estimates a plurality of waiting times for each of the plurality of respiration information. Further, the respiration estimation function 413 estimates the waiting time by a statistical method based on the plurality of waiting times. For example, the respiration estimation function 413 estimates that the average value or the median value of the plurality of waiting times is the waiting time for the apnea of the subject P to stabilize.

[0045] The notification function 414 controls the notification device 50 to notify the subject P of various matters by voice or image. For example, the notification function 414 notifies the subject P of apnea. The notification function 414 is an example of a notification unit.

[0046] More specifically, the notification function 414 notifies the subject P inserted into the hollow of the gantry device 10 of respiratory arrest. For example, the notification function 414 notifies the remaining time until the start of the scan, such as "There are still XX seconds until the start of the scan." For example, the notification function 414 notifies the remaining time until the start of the scan, such as "Please stop breathing." For example, the notification function 414 notifies that it is necessary to continue respiratory arrest because the scan is in progress, such as "The scan is in progress." Note that the notification function 414 may be notified by a notification device 50 arranged on the front of the gantry device 10. Thereby, the subject P and medical staff can recognize respiratory arrest and the like.

[0047] The display control function 415 displays the respiratory state of the subject P by controlling the display 42. More specifically, the display control function 415 displays on the display 42 the temporal change in the respiration of the subject P indicated by the respiration information. The display control function 415 is an example of a display control unit.

[0048] For example, the display control function 415 displays on the display 42 a graph showing the temporal change in the respiration of the subject P shown in FIG. 2. Further, the display control function 415 may display on the display 42 the standby time, the notification timing of respiratory arrest, the start timing of starting respiratory arrest, and the stabilization timing at which it is determined that the state of respiratory arrest has stabilized.

[0049] The system control function 416 controls various functions of the processing circuit 44 based on an input operation received from an operator via the input interface 43. For example, the system control function 416 controls the operation of the gantry device 10 to control the data collection process in the gantry device 10. Further, the system control function 416 controls the operation of the gantry device 10 so that the data collection process is executed under imaging conditions specified by the operator. The system control function 416 is an example of a system control unit.

[0050] For example, the system control function 416 receives an operation to scan the subject P on the gantry device 10. When the system control function 416 receives the operation to scan, it waits until the estimated waiting time by the respiration estimation function 413 elapses after the notification function 414 notifies the subject P of respiratory arrest. Then, when the waiting time elapses from the notification of respiratory arrest to the subject P by the notification function 414, the system control function 416 starts the scan of the subject P on the gantry device 10. The system control function 416 is an example of a control unit.

[0051] The preprocessing function 417 generates data obtained by performing preprocessing such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, and beam hardening correction on the detection data output from the DAS 18. Note that the data before preprocessing (detection data) and the data after preprocessing may be collectively referred to as projection data. The preprocessing function 417 is an example of a preprocessing unit.

[0052] The reconstruction processing function 418 performs reconstruction processing using, for example, the filtered back-projection method or the successive approximation reconstruction method on the projection data generated by the preprocessing function 417 to generate CT image data. The reconstruction processing function 418 stores the reconstructed CT image data in the memory 41. The reconstruction processing function 418 is an example of a reconstruction processing unit.

[0053] Also, the reconstruction processing function 418 may include the waiting time in the CT image data. Here, the CT image data is data in the DICOM (Digital Imaging and Communications in Medicine) format. For example, the reconstruction processing function 418 may include the waiting time in any of the DICOM tags. Further, the reconstruction processing function 418 may include the respiration information generated at the time of scanning the subject P by the X-ray CT apparatus 1 in the CT image data. In this way, by including the waiting time and respiration information in the DICOM tag, medical staff reading the CT image data can grasp the respiration of the patient when the CT image data was scanned.

[0054] The respiratory information storage function 419 stores the respiratory information generated by the respiratory information acquisition function 412 in the memory 41 or a storage unit such as a storage medium of another device when scanning the subject P by the X-ray CT apparatus 1. More specifically, the respiratory information storage function 419 stores, in the storage unit, respiratory information including the temporal change of the respiration of the subject P detected by the respiration sensor 20 during the period from the notification of breath-holding to breath-holding in the scan of the subject P. The respiratory information storage function 419 is an example of a storage control unit. For example, the respiratory information storage function 419 may store the standby time during the scan of the subject P by the X-ray CT apparatus 1 in the storage unit.

[0055] In addition, the respiratory information storage function 419 stores the patient identification information and the respiratory information in association with each other in the storage unit. Alternatively, the respiratory information storage function 419 stores the patient attribute information and the respiratory information in association with each other in the storage unit. Alternatively, the patient identification information, the patient attribute information, and the respiratory information are stored in association with each other in the storage unit. Thereby, the respiratory information storage function 419 generates a database having a plurality of pieces of respiratory information.

[0056] By generating the database, the respiration estimation function 413 estimates the standby time indicating the period from the notification of breath-holding to breath-holding based on the respiratory information acquired from the database having a plurality of pieces of respiratory information. For example, the respiration estimation function 413 estimates the standby time based on the respiratory information specified by the patient identification information. In addition, the respiration estimation function 413 may estimate the standby time based on the respiratory information specified by the patient attribute information. Further, the respiration estimation function 413 may estimate the standby time based on the respiratory information specified by the patient identification information and the patient attribute information.

[0057] Next, the scan process executed by the X-ray CT apparatus 1 will be described. The scan process is a process of scanning the chest and abdomen of the subject P in the X-ray CT apparatus 1. In other words, the scan process is a process of performing a scan with breath-holding of the subject P.

[0058] FIG. 3 is a flowchart showing an example of a scan process executed by the X-ray CT apparatus 1 according to the first embodiment.

[0059] The patient information acquisition function 411 acquires patient information of the patient who is the subject P (step S1).

[0060] The respiration information acquisition function 412 acquires respiration information of the subject P (step S2). The respiration information acquisition function 412 may generate respiration information by recording the respiration state detected by the respiration sensor 20 in the respiration suspension practice, or may acquire respiration information specified by the patient information from a storage unit such as the memory 41.

[0061] The respiration estimation function 413 estimates a waiting time indicating the period from the notification of respiration suspension to the respiration suspension based on the respiration information (step S3).

[0062] The system control function 416 determines whether or not an operation to execute a scan on the subject P has been received (step S4). When the scan operation has not been received (step S4; No), the system control function 416 waits.

[0063] When the scan operation has been received (step S4; Yes), the notification function 414 notifies the subject P of respiration suspension (step S5).

[0064] The system control function 416 determines whether or not the waiting time estimated by the respiration estimation function 413 has elapsed (step S6). When the waiting time has not elapsed (step S6; No), the system control function 416 waits.

[0065] When the waiting time has elapsed (step S6; Yes), the system control function 416 controls the gantry device 10 to scan the subject P (step S7).

[0066] The respiratory information storage function 419 stores the respiratory information generated during the scan of the subject P in a storage unit such as the memory 41 (step S8). For example, the respiratory information storage function 419 stores in the storage unit the standby time during the scan of the subject P by the X-ray CT apparatus 1.

[0067] As described above, the X-ray CT apparatus 1 ends the scan process.

[0068] As described above, the X-ray CT apparatus 1 according to the first embodiment acquires the respiratory information generated during the practice of breath-holding of the subject P or the respiratory information generated in the past. Further, the X-ray CT apparatus 1 estimates a standby time indicating the period from the notification of breath-holding to the actual breath-holding based on the respiratory information. Then, when the X-ray CT apparatus 1 receives an operation to scan the subject P, if the standby time has elapsed since the notification of breath-holding to the subject P, the X-ray CT apparatus 1 starts the scan of the subject P. In this way, the X-ray CT apparatus 1 estimates the timing at which the subject P can actually stop breathing based on the respiratory information acquired before the scan. Therefore, the X-ray CT apparatus 1 can adjust the start timing of the scan involving breath-holding according to the patient.

[0069] (Second Embodiment) The X-ray CT apparatus 1a according to the second embodiment estimates a respiratory state in which the subject P can continuously stop breathing for a specified period.

[0070] In order to prevent the subject P from generating unclear CT image data in the X-ray CT apparatus 1a due to the movement associated with breathing, the subject P needs to continuously stop breathing for a specified period. However, the subject P may not be able to continuously stop breathing for a specified period. For example, when the subject P inhales 100% air, the subject P cannot stop breathing for a specified period.

[0071] However, when the subject P inhales 80% of the air, it may be possible to stop breathing for a specified period. Therefore, the X-ray CT apparatus 1a estimates a breathing state in which breathing can be stopped for a specified period. Then, when the estimated breathing state is reached, the X-ray CT apparatus 1a notifies of the breathing stop.

[0072] For example, when the X-ray CT apparatus 1a reaches a breathing state in which it inhales 80% of the air, it notifies of the breathing stop. As a result, the subject P can stop breathing for a specified period. Therefore, the X-ray CT apparatus 1a can acquire a medical image that is not blurred due to the operation associated with breathing. Note that the specified period for which the subject P is required to continuously stop breathing is arbitrarily determined. For example, the specified period is determined according to the scan conditions.

[0073] FIG. 4 is a diagram showing an example of the configuration of the X-ray CT apparatus 1a according to the second embodiment. The processing circuit 44a of the console apparatus 40a has, for example, a patient information acquisition function 411, a breathing information acquisition function 412a, a breathing estimation function 413a, a notification function 414a, a display control function 415, a system control function 416a, a preprocessing function 417, a reconstruction processing function 418a, and a breathing information storage function 419a.

[0074] The breathing information acquisition function 412a acquires breathing information indicating the temporal change of breathing until the specified period for which the subject P is required to stop breathing has elapsed. More specifically, when the subject P continuously stops breathing for the specified period, the breathing information acquisition function 412a acquires breathing information including the breathing state immediately before the breathing stop. For example, the breathing information acquisition function 412a acquires breathing information including the inhalation volume immediately before the subject P stops breathing. In other words, the breathing information acquisition function 412a acquires breathing information including the expansion of the lungs, that is, the height of the chest, as the inhalation volume.

[0075] Further, the breathing information acquisition function 412a may generate breathing information by recording the breathing state detected by the breathing sensor 20 in the breathing stop practice, or may acquire breathing information from a storage unit such as the memory 41.

[0076] The respiration estimation function 413a estimates a waiting time indicating the period from the notification of respiratory arrest to respiratory arrest based on the respiration information acquired by the respiration information acquisition function 412a. Further, the respiration estimation function 413a estimates a respiratory state in which the subject P can continuously stop breathing for a specified period based on the respiration information acquired by the respiration information acquisition function 412a. In other words, the respiration estimation function 413a estimates the chest height at which the subject P can continuously stop breathing for a specified period based on the respiration information acquired by the respiration information acquisition function 412a. The respiration estimation function 413a estimates a waiting time indicating the period from the notification of respiratory arrest to respiratory arrest and a respiratory state in which the subject P can continuously stop breathing for a specified period based on the respiration information acquired by the respiration information acquisition function 412a.

[0077] Here, FIG. 5 is a graph showing an example of the change over time of the respiration of the subject P indicated by the respiration information. In FIG. 5, the horizontal axis indicates time, and the vertical axis indicates the respiratory state, that is, the chest height. Also, in FIG. 5, t0 indicates the waiting time, t1 indicates the notification timing of respiratory arrest, t2 indicates the start timing of starting to stop breathing after receiving the notification of respiratory arrest, t3 indicates the stabilization timing at which it is determined that the respiratory arrest state has stabilized, t4 indicates the respiratory arrest period during which the subject P has stopped breathing, and t5 indicates the restart timing at which the subject P has restarted breathing. Also, the respiratory arrest period is required to be equal to or longer than a specified period during which the subject P continuously stops breathing. Then, the X-ray CT apparatus 1a scans the subject P during the respiratory arrest period.

[0078] When the respiratory arrest period indicated by t4 is equal to or longer than the specified period, the respiration estimation function 413a estimates that the respiratory state at t1 is a respiratory state in which the subject P can continuously stop breathing for a specified period. That is, when the respiratory arrest period indicated by t4 is equal to or longer than the specified period, the respiration estimation function 413a estimates that the chest height at t1 is a chest height indicating a respiratory state in which the subject P can continuously stop breathing for a specified period.

[0079] The notification function 414a notifies of respiratory arrest in the case of the respiratory state estimated by the respiration estimation function 413a. That is, when the chest height indicating the respiratory state estimated by the respiration estimation function 413a is reached, the notification device 50 notifies the subject P of respiratory arrest.

[0080] More specifically, when an operation to scan the subject P is received by the system control function 416a, the notification function 414a determines whether the respiratory state detected by the respiration sensor 20 is at the chest height indicating the respiratory state estimated by the respiration estimation function 413a. The notification function 414a waits when the respiratory state detected by the respiration sensor 20 is not at the chest height indicating the respiratory state estimated by the respiration estimation function 413a. On the other hand, when the respiratory state detected by the respiration sensor 20 reaches the chest height indicating the respiratory state estimated by the respiration estimation function 413a, the notification function 414a notifies the subject P of respiratory arrest.

[0081] After the system control function 416a notifies the subject P of respiratory arrest by the notification function 414a, when the estimated waiting time by the respiration estimation function 413a has elapsed, the system control function 416a causes the gantry device 10 to perform a scan of the subject P.

[0082] The reconstruction processing function 418a generates CT image data by reconstruction processing. Then, the reconstruction processing function 418a may include in any of the DICOM tags of the CT image data obtained by scanning the subject P the waiting time indicating the period from the notification of respiratory arrest to respiratory arrest and the respiratory state in which the subject P can continue to stop breathing for a specified period. The reconstruction processing function 418a is an example of an additional part. That is, the reconstruction processing function 418a may include the chest height indicating the respiratory state in which the subject P can continue to stop breathing for a specified period. Further, the reconstruction processing function 418a may include the respiratory information generated at the time of scanning the subject P by the X-ray CT apparatus 1a in the CT image data.

[0083] The respiration information storage function 419a causes the storage unit to store respiration information indicating the change over time of the respiration of the subject P detected by the respiration sensor 20 during the scan of the subject P by the X-ray CT apparatus 1a. That is, the respiration information storage function 419a may cause the storage unit to store the standby time during the scan of the subject P by the X-ray CT apparatus 1a and the respiration state in which the subject P can continue to stop respiration for a specified period.

[0084] Thereby, the respiration estimation function 413a estimates the standby time and the respiration state in which the subject P can continue to stop respiration for a specified period based on the respiration information acquired from the database having a plurality of respiration information. For example, the respiration estimation function 413a estimates the standby time and the respiration state based on the respiration information specified by the patient identification information. Further, the respiration estimation function 413a may estimate the standby time and the respiration state based on the respiration information specified by the patient attribute information. Further, the respiration estimation function 413a may estimate the standby time and the respiration state based on the respiration information specified by the patient identification information and the patient attribute information.

[0085] Next, the scan process executed by the X-ray CT apparatus 1a will be described.

[0086] FIG. 6 is a flowchart showing an example of the scan process executed by the X-ray CT apparatus 1a according to the second embodiment.

[0087] The patient information acquisition function 411 acquires the patient information of the patient who is the subject P (step S11).

[0088] The respiration information acquisition function 412a acquires the respiration information of the subject P (step S12). The respiration information acquisition function 412a may generate respiration information by recording the respiration state detected by the respiration sensor 20 in the respiration stop practice, or may acquire the respiration information specified by the patient information from a storage unit such as the memory 41.

[0089] The respiration estimation function 413a estimates a standby time indicating the period from the notification of respiratory arrest to respiratory arrest based on respiration information (step S13).

[0090] The respiration estimation function 413a estimates the chest height indicating a respiratory state in which respiration can be continuously stopped for a specified period based on respiration information (step S14).

[0091] The system control function 416a determines whether an operation to cause the subject P to be scanned has been received (step S15). When the scan operation has not been received (step S15; No), the system control function 416a waits.

[0092] When the scan operation has been received (step S15; Yes), the notification function 414a determines whether the notification conditions for notifying the subject P of respiratory arrest are satisfied (step S16). That is, the notification function 414a determines whether the respiratory state detected by the respiration sensor 20 is at the chest height indicating the respiratory state estimated by the respiration estimation function 413a. When the notification conditions are not satisfied (step S16; No), the notification function 414a waits.

[0093] On the other hand, when the notification conditions are satisfied, that is, when the respiratory state detected by the respiration sensor 20 is at the chest height indicating the respiratory state estimated by the respiration estimation function 413a (step S16; Yes), the notification function 414a notifies the subject P of respiratory arrest (step S17).

[0094] The system control function 416a determines whether the standby time estimated by the respiration estimation function 413a has elapsed (step S18). When the standby time has not elapsed (step S18; No), the system control function 416a waits.

[0095] When the standby time has elapsed (step S18; Yes), the system control function 416a controls the gantry device 10 to scan the subject P (step S19).

[0096] The respiratory information storage function 419a stores the respiratory information generated during the scan of the subject P in a storage unit such as the memory 41 (step S20). For example, the respiratory information storage function 419a stores in the storage unit the standby time during the scan of the subject P by the X-ray CT apparatus 1a and the respiratory state in which the subject P can continuously stop breathing for a specified period.

[0097] Thus, the X-ray CT apparatus 1a ends the scan process.

[0098] As described above, the X-ray CT apparatus 1a according to the second embodiment acquires the respiratory information generated during the practice of the breath-holding of the subject P or the respiratory information generated in the past. The X-ray CT apparatus 1a estimates the chest height indicating the respiratory state in which breathing can be stopped for a specified period based on the respiratory information. Then, when the chest height indicating the estimated respiratory state is reached, the X-ray CT apparatus 1a notifies the subject P to stop breathing. Therefore, the X-ray CT apparatus 1a can adjust the start timing of the scan involving breath-holding according to the patient.

[0099] (Modification 1) In the first and second embodiments, the case where the present invention is applied to the X-ray CT apparatuses 1 and 1a as an example of a medical image diagnostic apparatus has been described. However, the medical image diagnostic apparatus is not limited to the X-ray CT apparatuses 1 and 1a, and may be applied to a general X-ray diagnostic apparatus, an MRI (Magnetic Resonance Imaging) apparatus, a PET (Positron Emission Tomography) apparatus, or a CT-PET apparatus in which an X-ray CT apparatus and a PET apparatus are combined.

[0100] According to at least one of the embodiments described above, the start timing of the scan involving breath-holding can be adjusted according to the patient.

[0101] Although some 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, replacements, changes, and combinations of embodiments can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0102] 1, 1a X-ray CT apparatus 10 Gantry device 20 Respiration sensor 40, 40a Console device 41 Memory 42 Display 43 Input interface 44, 44a Processing circuit 50 Notification device 411 Patient information acquisition function 412, 412a Respiration information acquisition function 413, 413a Respiration estimation function 414, 414a Notification function 415 Display control function 416, 416a System control function 417 Pretreatment function 418, 418a Reconstruction processing function 419, 419a Respiration information storage function P Subject

Claims

1. A first acquisition unit that acquires respiratory information indicating the temporal change in the respiration of a subject; An estimation unit that estimates a standby time indicating the period from the notification of respiratory arrest to the occurrence of respiratory arrest based on the respiratory information; A control unit that starts a scan of the subject when the standby time has elapsed since the notification of respiratory arrest to the subject; A medical imaging diagnostic apparatus comprising the above.

2. A respiration detection unit that detects the respiratory state of a subject; In the scan of the subject, a storage control unit that causes a storage unit to store the respiratory information including the temporal change in the respiration of the subject detected by the respiration detection unit during the period from the notification of respiratory arrest to the occurrence of respiratory arrest; The medical imaging diagnostic apparatus according to Claim 1.

3. Further comprising a second acquisition unit that acquires subject identification information for identifying a subject; The storage control unit stores the subject identification information and the respiratory information in association with each other in the storage unit; The estimation unit estimates the standby time based on the respiratory information specified by the subject identification information. The medical imaging diagnostic apparatus according to Claim 2.

4. Further comprising a third acquisition unit that acquires subject attribute information indicating the attributes of a subject; The storage control unit stores the subject attribute information and the respiratory information in association with each other in the storage unit; The estimation unit estimates the standby time based on the respiratory information specified by the subject attribute information. The medical imaging diagnostic apparatus according to Claim 2.

5. Further comprising a notification unit that notifies the subject of respiratory arrest; The control unit starts the scan of the subject when the standby time has elapsed since the notification of respiratory arrest by the notification unit. The medical imaging diagnostic apparatus according to Claim 1.

6. The estimation unit estimates the standby time indicating the period from the notification of respiratory arrest to the occurrence of respiratory arrest and the respiratory state in which the subject can continue to stop breathing for a specified period based on the respiratory information; The notification unit notifies of respiratory arrest in the case of the respiratory state; The control unit starts the scan of the subject when the standby time has elapsed since the notification of respiratory arrest by the notification unit. The medical imaging diagnostic apparatus according to Claim 5.

7. Further comprising an addition unit that includes in the medical image acquired by the scan the standby time indicating the period from the notification of respiratory arrest to the occurrence of respiratory arrest and the respiratory state in which the subject can continue to stop breathing for a specified period. The medical image diagnostic apparatus according to claim 6.

8. Further comprising a display control unit that displays the temporal change in the respiration of the subject. The medical image diagnostic apparatus according to any one of claims 1 to 7.

9. Obtaining respiration information indicating the temporal change in the respiration of the subject, estimating a waiting time indicating the period from the notification of respiratory arrest to respiratory arrest based on the respiration information, starting a scan of the subject when the waiting time has elapsed from the notification of respiratory arrest to the subject. A control method including this.

10. Causing a computer to obtain respiration information indicating the temporal change in the respiration of the subject, estimate a waiting time indicating the period from the notification of respiratory arrest to respiratory arrest based on the respiration information, start a scan of the subject when the waiting time has elapsed from the notification of respiratory arrest to the subject. A program for realizing this.

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