JP2019201710A - Medical image diagnostic apparatus, medical image processor, and program - Google Patents

Abstract

To perform appropriate imaging of the heart.SOLUTION: A medical image diagnostic apparatus in an embodiment includes a specification part and a processing part. The specification part acquires heart sound information and electrocardiographic information from an analyte, and specifies a time phase of imaging or of reorganization from the heart sound information and the electrocardiographic information. The processing part performs imaging of the analyte based on the time phase of the imaging, or performs reorganization of the analyte based on the time phase of the reorganization.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a medical image diagnostic apparatus, a medical image processing apparatus, and a program.

  In the case of imaging of the heart by a medical image diagnostic apparatus such as an X-ray CT apparatus, a magnetic resonance imaging apparatus, or an ultrasonic diagnostic apparatus, conventionally, in order to avoid image quality deterioration due to the movement of the heart, the cardiac systole or diastole is determined by electrocardiographic information. Such a phase was estimated, and photography was performed at a time phase in which the heart movement was small.

  However, as one aspect of the imaging of the heart, when imaging of the heart valve state is performed, the movement of the heart valve is caused by blood flow and is not directly related to the electrocardiographic information. There were cases where accurate shooting could not be performed in the time phase based on information. In particular, it is not appropriate to control the imaging timing based on the time phase estimated from the electrocardiogram information for a patient with an abnormal excitation propagation.

JP 2000-51208 A

  The problem to be solved by the present invention is to enable appropriate imaging of the heart.

  The medical image diagnostic apparatus according to the embodiment includes a specifying unit and a processing unit. The specifying unit acquires heart sound information and electrocardiogram information from the subject, and specifies a time phase of imaging or reconstruction from the heart sound information and the electrocardiogram information. The processing unit images the subject based on the time phase of the imaging, or reconfigures the subject based on the time phase of the reconstruction.

FIG. 1 is a block diagram illustrating a configuration example of an X-ray CT apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of a mounting position of the heart sound sensor. FIG. 3 is a block diagram illustrating a configuration example of a workstation. FIG. 4 is a flowchart illustrating an example of processing in the first embodiment. FIG. 5A is a diagram (1) illustrating an example of how heart sounds are determined. FIG. 5B is a diagram (2) illustrating an example of how heart sound is determined. FIG. 5C is a diagram (3) illustrating an example of how heart sound is determined. FIG. 6 is a diagram illustrating waveform examples of heart sound information and electrocardiogram information. FIG. 7 is a flowchart illustrating an example of processing in the second embodiment. FIG. 8A is a diagram (1) illustrating an example of a heart sound when there is a disease. FIG. 8B is a diagram (2) illustrating an example of a heart sound when there is a disease. FIG. 9 is a diagram showing detailed waveform examples of heart sounds when normal and when there is a disease. FIG. 10 is a flowchart (1) illustrating a processing example in the third embodiment. FIG. 11 is a diagram illustrating an example of collected data. FIG. 12 is a flowchart (2) illustrating a processing example in the third embodiment.

  Hereinafter, embodiments of a medical image diagnostic apparatus, a medical image processing apparatus, and a program will be described with reference to the drawings. The embodiment is not limited to the following contents. In addition, the contents described in one embodiment or modification can be applied to other embodiments and modifications in principle as well.

(First embodiment)
The configuration of the X-ray CT apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration example of an X-ray CT apparatus 1 according to the first embodiment. The X-ray CT apparatus 1 is an example of a medical image diagnostic apparatus. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40. For convenience of explanation, in FIG. 1, a plurality of gantry devices 10 are drawn, but basically there is one gantry device 10 as an actual configuration. In FIG. 1, the rotation axis of the rotating frame 16 or the longitudinal direction of the top plate 33 of the bed apparatus 30 when the gantry apparatus 10 is not tilted is defined as the Z-axis direction. Further, an axial direction that is orthogonal to the Z-axis direction and is horizontal to the floor surface is taken as an X-axis direction. Further, an axial direction orthogonal to the Z-axis direction and perpendicular to the floor surface is defined as a Y-axis direction.

  The gantry device 10 includes an X-ray tube 11, an X-ray detector 15, a rotating frame 16, an X-ray high voltage device 17, a control device 18, a wedge 19, a collimator 20, and a DAS (Data Acquisition System). 21. The gantry device 10 also includes a heart sound sensor 22, a heart sound information acquisition circuit 23, an electrode 24, and an electrocardiogram information acquisition circuit 25.

  The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermoelectrons from a cathode (filament) to an anode (target) with a high voltage from the X-ray high-voltage device 17. The present embodiment can be applied to a single tube type X-ray CT apparatus and a so-called multi-tube type X-ray CT apparatus in which a plurality of pairs of X-ray tubes and detectors are mounted on a rotating ring. It is. Further, hardware for generating X-rays is not limited to the X-ray tube 11. For example, instead of the X-ray tube 11, a focus coil that focuses an electron beam generated from an electron gun, a deflection coil that electromagnetically deflects, and an electron beam that surrounds the half circumference of the subject P collide with each other to collide X-rays. X-rays may be generated using a fifth generation method including a target ring to be generated.

  The X-ray high voltage device 17 includes an electric circuit such as a transformer and a rectifier, and generates a high voltage to be applied to the X-ray tube 11 and X-rays emitted from the X-ray tube 11. And an X-ray control circuit for controlling the output voltage according to the above. The high voltage generation circuit may be a transformer system or an inverter system. The X-ray high voltage device 17 not only generates a high voltage, but also supplies power to the filament, and supplies driving power when the anode is a rotary type. Further, the X-ray high voltage device 17 may be provided on the rotating frame 16 or may be provided on the fixed frame (not shown) side of the gantry device 10. The fixed frame is a frame that rotatably supports the rotating frame 16.

  The X-ray detector 15 detects X-rays irradiated from the X-ray tube 11 and passing through the subject P, and outputs a signal corresponding to the detected X-ray dose to the DAS 21. The X-ray detector 15 includes, for example, a plurality of X-ray detection element arrays in which a plurality of X-ray detection elements are arranged in the channel direction (circumferential direction) along one arc centered on the focal point of the X-ray tube 11. Have. For example, the X-ray detector 15 has a structure in which a plurality of X-ray detection element arrays in which a plurality of X-ray detection elements are arrayed in the channel direction are arrayed in the slice direction (column direction, row direction).

  The X-ray detector 15 is an indirect conversion type detector having a grid, a scintillator array, and an optical sensor array, for example. The scintillator array has a plurality of scintillators. The scintillator has a scintillator crystal that outputs a photon amount of light corresponding to the incident X-ray dose. The grid is disposed on the surface on the X-ray incident side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid may be called a collimator (a one-dimensional collimator or a two-dimensional collimator). The optical sensor array has a function of converting into an electrical signal corresponding to the amount of light from the scintillator, and includes, for example, an optical sensor such as a photodiode or a photomultiplier tube (photomultiplier: PMT). The X-ray detector 15 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into electrical signals.

  The rotating frame 16 (base frame) is an annular frame that supports the X-ray tube 11 and the X-ray detector 15 opposite to each other and rotates the X-ray tube 11 and the X-ray detector 15 by the control device 18. For example, the rotating frame 16 is a casting made of aluminum. The rotating frame 16 can further support the X-ray high voltage device 17 and the DAS 21 in addition to the X-ray tube 11 and the X-ray detector 15. Further, the rotating frame 16 can further support various configurations not shown in FIG. Hereinafter, in the gantry device 10, a portion that rotates together with the rotating frame 16 and the rotating frame 16 are also referred to as a rotating unit. Note that the Rotate / Rotate-Type (third generation CT) in which the X-ray tube 11 and the X-ray detector 15 are integrally rotated around the subject P has been described. There are various types such as Stationary / Rotate-Type (fourth generation CT) in which a large number of X-ray detection elements are fixed and only the X-ray tube 11 rotates around the subject P, and any type goes to this embodiment. Applicable.

  The detection data generated by the DAS 21 is a photodiode provided in a non-rotating portion of the gantry device 10 by optical communication from a transmitter having a light emitting diode (LED) provided in the rotating frame 16. Is transmitted to the console device 40. Here, the non-rotating portion is, for example, a fixed frame (not shown in FIG. 1) that rotatably supports the rotating frame 16. The detection data transmission method from the rotating frame 16 to the non-rotating portion of the gantry device 10 is not limited to optical communication, and any method can be used as long as data transmission can be performed between the rotating portion and the non-rotating portion. It doesn't matter.

  The control device 18 includes a driving mechanism such as a motor and an actuator, and a circuit that controls the mechanism. The control device 18 receives input signals from the input interface 43 and the input interface provided in the gantry device 10 and controls the operation of the gantry device 10 and the couch device 30. For example, the control device 18 controls the rotation of the rotating frame 16, the tilt of the gantry device 10, the operations of the bed device 30 and the top plate 33, and the like. For example, as a control for tilting the gantry device 10, the control device 18 rotates the rotating frame 16 around an axis parallel to the X-axis direction based on the input tilt angle (tilt angle) information. The control device 18 may be provided in the gantry device 10 or may be provided in the console device 40.

  The wedge 19 is a filter for adjusting the X-ray dose irradiated from the X-ray tube 11. Specifically, the wedge 19 transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. It is a filter to do. For example, the wedge 19 is a wedge filter or a bow-tie filter, and is configured by processing aluminum or the like so as to have a predetermined target angle or a predetermined thickness.

  The collimator 20 is a lead plate or the like for narrowing the irradiation range of X-rays transmitted through the wedge 19 and forms a slit by a combination of a plurality of lead plates or the like. The collimator 20 is sometimes called an X-ray diaphragm. The collimator 20 is adjusted in opening degree and position by a collimator adjustment circuit (not shown). Thereby, the irradiation range of the X-rays generated by the X-ray tube 11 is adjusted.

  The DAS 21 includes an amplifier that performs amplification processing on the electric signal output from each X-ray detection element of the X-ray detector 15 and an A / D converter that converts the electric signal into a digital signal. Is generated. The DAS 21 is realized by a processor, for example. The detection data generated by the DAS 21 is transferred to the console device 40.

  The heart sound sensor 22 is, for example, one or a plurality of microphones, is attached to the body surface of the subject P, and outputs an electrical signal corresponding to the heart sound. The heart sound information acquisition circuit 23 converts the output of the heart sound sensor 22 into, for example, a digital signal suitable for subsequent processing, and the converted signal is transferred to the console device 40. The heart sound information may be transferred to the console device 40 via the DAS 21. A signal indicating the waveform of the heart sound is used as heart sound information. The heart sound information may include information on a position where the heart sound sensor 22 is mounted in order to acquire the heart sound.

FIG. 2 is a diagram illustrating an example of the mounting position of the heart sound sensor 22. 2, region A ₁ is the aortic region of the second intercostal sternum right edge, an area where the sound of the aortic valve and the aorta are most strongly auscultation. Area A ₂ is a pulmonary artery area of the second intercostal sternum left edge, a region where the sound of the pulmonary valve and the pulmonary artery is most strongly auscultation. Area A ₃ is a region of the third intercostal left sternal border Elp is a convenient area to listen to the sound of the aorta and pulmonary artery origins. Area A ₄ is a tricuspid region of the fourth intercostal space left sternal border, an area where the sound of the tricuspid and right chambers are most strongly auscultation. Region A ₅ represents a mitral valve area at the intersection of the left fifth intercostal and clavicular midline, located directly above the left ventricle, and sometimes contains apical strongest listening sound associated with mitral valve and left ventricle It is an area to be done. In addition, although not shown, the heart sound sensor 22 may be provided in the neck.

  Returning to FIG. 1, the electrode 24 is, for example, a plurality of sucker type, seal type, or clip type members, and extracts an electrocardiographic signal from the subject P. The electrocardiogram information acquisition circuit 25 converts the electrocardiogram signals acquired from the plurality of electrodes 24 into, for example, a digital signal suitable for subsequent processing, and the converted signal is transferred to the console device 40. The plurality of electrodes 24 are mounted at a general position for acquiring an electrocardiogram signal. The electrocardiogram information may be transferred to the console device 40 via the DAS 21. The signal indicating the waveform of the action potential or action current of the myocardium accompanying the heartbeat is used as the electrocardiogram information.

  The couch device 30 is a device for placing and moving the subject P to be scanned, and includes a base 31, a couch 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 couch driving device 32 is a driving mechanism that moves the top plate 33 on which the subject P is placed in the long axis 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. The couch driving device 32 may move the support frame 34 in the long axis direction of the top plate 33 in addition to the top plate 33. Only the top plate 33 may be moved, or a method of moving together with the support frame of the bed apparatus 30 may be used. When applied to standing CT, a method of moving a patient support mechanism corresponding to the top board 33 may be used. When performing a scan (helical scan, positioning scan, etc.) involving a relative change in the positional relationship of the top plate 33 of the gantry device 10, the relative change in the positional relationship may be performed by driving the top plate 33. However, it may be performed by running the gantry device 10 or may be performed by combining them. When applied to dental CT, the bed apparatus 30 or the like is not necessary.

  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.

  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. For example, the memory 41 stores projection data and reconstructed image data. Further, for example, the memory 41 stores a program for a circuit included in the X-ray CT apparatus 1 to realize its function. The memory 41 is also used as a non-transitory storage medium by hardware. Note that the storage of projection data and reconstructed image data is not limited to the case of the memory 41 of the console device 40, but a cloud server that can be connected to the X-ray CT apparatus 1 via a communication network such as the Internet is an X-ray CT apparatus. In response to the storage request from 1, the projection data and the reconstructed image data may be stored.

  The display 42 displays various information. For example, the display 42 outputs a medical image (CT image) generated by the processing circuit 44, a GUI (Graphical User Interface) for receiving various operations from the operator, and the like. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 42 is an example of a display unit. The display 42 may be provided in the gantry device 10. Further, 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 device 40 main body.

  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. For example, the input interface 43 receives from the operator collection conditions when collecting projection data, reconstruction conditions when reconstructing a CT image, image processing conditions when generating a post-process image from a CT image, and the like. . For example, the input interface 43 is realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch panel, or the like. Further, the input interface 43 may be provided in the gantry device 10. Further, the input interface 43 may be configured by a tablet terminal or the like capable of wireless communication with the console device 40 main body.

  The processing circuit 44 controls the operation of the entire X-ray CT apparatus 1. For example, the processing circuit 44 includes a scan control function 441, an image generation function 442, a display control function 443, and a control function 444. The processing circuit 44 is realized by a processor, for example.

  For example, the processing circuit 44 reads the program corresponding to the scan control function 441 from the memory 41 and executes it, thereby controlling the X-ray CT apparatus 1 and executing a scan. Here, the scan control function 441 can execute scanning by various methods such as a conventional scan, a helical scan, and a step-and-shoot method, for example.

  Specifically, the scan control function 441 moves the subject P into the imaging port of the gantry device 10 by controlling the bed driving device 32. Further, the scan control function 441 controls the X-ray high voltage device 17 to supply a high voltage to the X-ray tube 11. The scan control function 441 adjusts the aperture and position of the collimator 20. In addition, the scan control function 441 rotates the rotating unit including the rotating frame 16 by controlling the control device 18. The scan control function 441 causes the DAS 21 to collect projection data. In order to reconstruct a CT image, projection data for 360 ° around the subject P is required, and projection data for 180 ° + fan angle is required even in the half scan method. The present embodiment can be applied to any reconfiguration method.

  The scan control function 441 can specify the time phase of imaging based on heart sound information and electrocardiographic information when taking an image of the heart, and can perform imaging at the specified time phase. When the imaging time phase is not specified, the scan control function 441 can perform imaging for a predetermined period including one cycle of pulsation, and can simultaneously record heart sound information and electrocardiogram information. Further, the scan control function 441 can estimate a heart disease from heart sound information, and can specify an imaging time phase suitable for the estimated disease. The scan control function 441 may estimate a heart disease using heart sound information and electrocardiogram information.

  Further, for example, the processing circuit 44 reads out and executes a program corresponding to the image generation function 442 from the memory 41, thereby performing logarithmic conversion processing, offset correction processing, and channel sensitivity on the detection data output from the DAS 21. Data subjected to preprocessing such as correction processing and beam hardening correction is generated. Note that data before detection (detection data) and data after preprocessing may be collectively referred to as projection data. For example, the image generation function 442 generates CT image data. Specifically, the image generation function 442 generates CT image data by performing a reconstruction process using a filtered back projection method, a successive approximation reconstruction method, or the like on the projection data after the preprocessing. The image generation function 442 converts CT image data into tomographic image data or three-dimensional image data of an arbitrary cross section based on an input operation received from an operator via the input interface 43.

  In addition, the image generation function 442 can perform reconstruction from the projection data of the heart that is imaged with the time phase specified by the scan control function 441. When shooting is performed without specifying the shooting time phase, the image generation function 442 specifies the time phase of reconstruction based on the heart sound information and the electrocardiogram information recorded together with the projection data. Reconfiguration can be performed in the time phase. Further, the image generation function 442 can estimate a heart disease from heart sound information, and can specify a reconstruction time phase suitable for the estimated disease. The image generation function 442 may estimate a heart disease using the heart sound information and the electrocardiogram information. The scan control function 441 or the image generation function 442 is an example of a specifying unit, a processing unit, or an estimation unit.

  Further, for example, the processing circuit 44 reads a program corresponding to the display control function 443 from the memory 41 and executes it, thereby displaying a CT image on the display 42. In addition, the display control function 443 displays a diagnostic image suitable for the estimated disease (confirmation of the disease state) when the disease is estimated by the scan control function 441 or the image generation function 442 based on the result of the heart reconstruction. Can be displayed as an initial image.

  Further, for example, the processing circuit 44 reads out and executes a program corresponding to the control function 444 from the memory 41, thereby performing various functions of the processing circuit 44 based on an input operation received from the operator via the input interface 43. To control.

  FIG. 1 shows a case where the processing functions of the scan control function 441, the image generation function 442, the display control function 443, and the control function 444 are realized by a single processing circuit 44. It is not limited to. For example, the processing circuit 44 may be configured by combining a plurality of independent processors, and each processor may implement each processing function by executing each program. In addition, each processing function of the processing circuit 44 may be realized by being appropriately distributed or integrated into a single or a plurality of processing circuits. The processing circuit 44 is not limited to being included in the console device 40, and may be included in an integrated server that collectively performs processing on detection data acquired by a plurality of medical image diagnostic apparatuses. Although the console device 40 has been described as executing a plurality of functions using a single console, a plurality of functions may be executed by different consoles. Post-processing may be performed by either the console device 40 or an external workstation. Moreover, you may decide to process by both the console apparatus 40 and a workstation. Further, reconstruction based on projection data may be performed in an external workstation.

  FIG. 3 is a block diagram illustrating a configuration example of the workstation 50. The workstation 50 is an example of a medical image processing apparatus. In FIG. 3, the workstation 50 includes a memory 51, a display 52, an input interface 53, and a processing circuit 54. The processing circuit 54 has an image generation function 542, a display control function 543, and a control function 544. The memory 51, the display 52, the input interface 53, and the processing circuit 54 of the workstation 50 correspond to the memory 41, the display 42, the input interface 43, and the processing circuit 44 of the console device 40 of the X-ray CT apparatus 1, and the hardware configuration and The function is similar. The processing circuit 54 is realized by a processor, for example. However, the processing circuit 54 does not have a function corresponding to the scan control function 441 because the workstation 50 does not perform the scan control by itself. The workstation 50 acquires projection data and the like used for reconstruction from the console device 40 side of the X-ray CT apparatus 1 via a network (cloud) or a recording medium. The image generation function 542 is an example of a specifying unit, a processing unit, or an estimation unit.

  The term “processor” used in the above description is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), a programmable logic device (for example, It means a circuit such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA). The processor implements a function by reading and executing a 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 incorporated in the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining a plurality of independent circuits to realize the function. Good.

  FIG. 4 is a flowchart showing an example of processing in the first embodiment. In the X-ray CT apparatus 1, when imaging a heart, imaging is performed at an imaging time phase specified based on heart sound information and electrocardiogram information. It is an example of a process when it is performed and a reconstruction and an image display are performed continuously.

  In FIG. 4, the scan control function 441 acquires heart sound information from the subject P via the heart sound sensor 22 and the heart sound information acquisition circuit 23, and from the subject P via the electrode 24 and the electrocardiogram information acquisition circuit 25. Information is acquired (step S11).

  Next, the scan control function 441 determines (classifies) the first sound, the second sound, etc. mainly using the heart sound information and the electrocardiographic information as a sub (step S12). The first sound is a sound generated when the atrioventricular valve (mitral valve, tricuspid valve) closes. The second sound is a sound generated when the arterial valve (aortic valve, pulmonary valve) is closed. There are other sounds such as III. The third sound is generated when blood flows from the atria to the ventricles. Therefore, the closing time of the atrioventricular valve (mitral valve, tricuspid valve) can be known from the first sound. The closing time of the arterial valve (aortic valve, pulmonary valve) can be seen from the second sound. By combining the heart sound information and the electrocardiogram information, the end diastole time can also be estimated.

  FIG. 5A to FIG. 5C are diagrams showing an example of how heart sounds are determined. FIG. 5A shows a case where determination is performed based on heart sound information from the output of one heart sound sensor 22 and electrocardiogram information. In this case, the scan control function 441 determines the first sound, the second sound, and the like from the heart sound information and the electrocardiogram information output from one heart sound sensor 22. For example, with respect to the first sound and the second sound, generally, the first sound is a sound of a lower frequency band than the second sound, and the second sound and the first sound are shorter than the interval between the first sound and the second sound. For example, the scan control function 441 temporarily specifies the first and second sounds from the waveform of the heart sound information.

Next, the scan control function 441 identifies the first sound and the second sound using the electrocardiogram information. Figure 6 is a diagram showing an example of the waveform of the heart sound information and electrocardiogram information, the sound I W ₁ of the heart sound information is generated immediately after the R-wave W _R in the electrocardiogram information, second sound II followed by W ₂ Is shown to occur. Thus, the scan control function 441 for a tentatively first sound I and the II sound identified, to consider the positional relationship between the R wave W _R in the electrocardiogram information, identifying a first sound I and the II sound . Although only the relationship with the R wave has been described, the relationship between the heart sound and other characteristic waveforms included in the electrocardiogram information can also be used. If sufficient determination can be made from the heart sound information, the electrocardiogram information need not be used for the determination.

  FIG. 5B shows a case where determination is performed based on the output of one heart sound sensor 22 and the heart sound information based on the mounting position and the electrocardiogram information. The mounting position of the heart sound sensor 22 may be determined in advance by operation, the user may input the mounting position, or the mounting position may be automatically acquired mechanically. Further, based on patient information of the subject P, etc., candidate mounting positions may be proposed to the user from the apparatus side.

  In this case, the scan control function 441 determines the first sound, the second sound, and the like from the output of one heart sound sensor 22 and the heart sound information and the electrocardiogram information according to the mounting position. As described with reference to FIG. 2, the easy-to-hear sound varies depending on the mounting position of the heart sound sensor 22, so that it is easy to identify the first sound and the second sound. For example, since the magnitude relationship of the respective detection levels of the first sound and the second sound and the rough intensity ratio are known in advance depending on the mounting position, the first sound and the second sound are detected from the detection level based on the current mounting position. The judgment material for distinguishing the sound is obtained, and the identification of the first sound and the second sound is facilitated by considering together with other elements such as the frequency band described above. The scan control function 441 refers to, for example, a table in which the magnitude relationship between the detection levels of the first sound and the second sound for each mounting position and a rough intensity ratio are stored, and the heart sound information actually detected It is compared with the detected level, and it is determined which is likely to be the first sound or the second sound, and the first sound and the second sound are specified in combination with the determination by other factors. The scan control function 441 tentatively determines the first sound, the second sound, etc. from the heart sound information, and then performs identification using the relationship with the electrocardiogram information shown in FIG. If it can be performed, the electrocardiogram information need not be used for the determination.

  FIG. 5C shows a case where the determination is performed based on the outputs of the plurality of heart sound sensors 22, the heart sound information based on the respective mounting positions, and the electrocardiogram information. The plurality of mounting positions of the heart sound sensor 22 may be determined in advance, the user may input a plurality of mounting positions, or the plurality of mounting positions may be automatically acquired mechanically. . In addition, based on patient information of the subject P, a plurality of candidate mounting positions may be proposed to the user from the apparatus side.

  In this case, the scan control function 441 determines the first sound, the second sound, and the like from the outputs of the plurality of heart sound sensors 22 and the heart sound information and the electrocardiogram information according to the respective mounting positions. As described with reference to FIG. 2, the sound that is easy to hear differs depending on the mounting position of the heart sound sensor 22, and heart sounds from a plurality of mounting positions can be determined simultaneously and comprehensively. Identification becomes easy. For example, since the magnitude relationship and the approximate intensity ratio of the detection levels of the first sound and the second sound are grasped in advance depending on the mounting position, the detection level status from each of the plurality of current mounting positions is known. Therefore, it becomes possible to identify the first sound and the second sound with higher accuracy. The scan control function 441 refers to, for example, a table in which the magnitude relationship between the detection levels of the first sound and the second sound for each mounting position and a rough intensity ratio are stored, and the heart sound information actually detected It is compared with the detected level, and it is determined which is likely to be the first sound or the second sound, and the first sound and the second sound are specified in combination with the determination by other factors. The scan control function 441 tentatively determines the first sound, the second sound, etc. from the heart sound information, and then performs identification using the relationship with the electrocardiogram information shown in FIG. If it can be performed, the electrocardiogram information need not be used for the determination.

  Returning to FIG. 4, the scan control function 441 determines a time phase as a center of photographing based on the time phases respectively corresponding to the identified first sound and second sound (step S <b> 13). The time phases respectively corresponding to the first sound and the second sound may be obtained from, for example, the first sound, the second sound, etc. detected immediately before determining the time phase from the heart sound information. You may make it obtain | require by an average from the detection of times. It is desirable that the time phase that becomes the center of imaging is determined to be an intermediate time phase between the first sound and the second sound that are in the middle systole, for example, for the imaging of the mitral valve. The imaging of the aortic valve is preferably determined at a time phase between the second sound and the first sound, which is the middle diastole (around 1/3 from the second sound). The time phase is determined, for example, several milliseconds after the I-th sound and several milliseconds after the R wave.

  Next, the scan control function 441 performs imaging (X-ray exposure and transmission X-ray detection) at the determined time phase (step S14). Since the time phase of imaging is determined in advance and the minimum X-ray exposure necessary for imaging is sufficient, the amount of exposure can be reduced.

  Next, the image generation function 442 performs reconstruction based on the projection data obtained by imaging, and generates CT image data (step S15). The CT image data is converted into tomographic image data or three-dimensional image data of an arbitrary cross section based on an input operation received from the operator. Note that the processing after the reconstruction may be performed by the image generation function 542 of the workstation 50 based on the projection data.

  Next, the display control function 443 displays an image based on the CT image obtained by the reconstruction, the tomographic image data of an arbitrary cross section, and the three-dimensional image data on the display 42 (step S16). When the reconstruction is performed by the image generation function 542 of the workstation 50, the image display is performed by the display control function 543 of the workstation 50.

  Steps S11 to S14 shown in FIG. 4 correspond to the scan control function 441. Steps S11 to S14 are steps in which the scan control function 441 is realized by the processing circuit 44 reading and executing a program corresponding to the scan control function 441 from the memory 41.

  Step S15 shown in FIG. 4 corresponds to the image generation function 442 or the image generation function 542. In step S15, the processing circuit 44 or the processing circuit 54 reads out and executes a program corresponding to the image generation function 442 or the image generation function 542 from the memory 41 or 51, thereby realizing the image generation function 442 or the image generation function 542. Step.

  Step S <b> 16 illustrated in FIG. 4 is a step corresponding to the display control function 443 or the display control function 543. In step S16, the display control function 443 or the display control function 543 is realized by the processing circuit 44 or the processing circuit 54 reading and executing a program corresponding to the display control function 443 or the display control function 543 from the memory 41 or the memory 51. Step.

  In addition, although embodiment applied to the X-ray CT apparatus was described, it can apply similarly to other medical image diagnostic apparatuses, such as a magnetic resonance imaging apparatus or an ultrasonic diagnostic apparatus.

  According to this embodiment, the time phase of imaging is determined from heart sound information and the like, and appropriate imaging of the heart can be performed. In addition, since the exposure to the minimum amount of X-rays necessary for imaging is sufficient, the amount of exposure can be reduced.

(Second Embodiment)
The configuration example of the X-ray CT apparatus 1, the example of the mounting position of the heart sound sensor 22, and the configuration example of the workstation 50 are the same as those in FIGS.

  FIG. 7 is a flowchart showing a processing example in the second embodiment. In the X-ray CT apparatus 1, the first sound, the second sound, etc. are determined from the heart sound information and the electrocardiogram information when the heart is imaged. This is an example of processing when imaging is performed at a reconstruction time phase suitable for a disease inferred from information, and then reconstruction and image display are performed.

  In FIG. 7, the scan control function 441 acquires heart sound information from the subject P via the heart sound sensor 22 and the heart sound information acquisition circuit 23, and from the subject P via the electrode 24 and the electrocardiogram information acquisition circuit 25. Information is acquired (step S21).

  Next, the scan control function 441 determines the first sound, the second sound, etc., mainly using the heart sound information and the electrocardiographic information as the sub (step S22). The determination of the first sound, the second sound, and the like is performed in the same manner as described in FIGS. 5A to 5C.

  Next, the scan control function 441 estimates a disease from the heart sound information (step S23). Note that electrocardiogram information may be used in combination with disease estimation. The disease is determined from, for example, heart noise included in the heart sound information. 8A and 8B are diagrams showing examples of heart sounds when there is a disease. In FIGS. 8A and 8B, the timing of the I-th sound is indicated by “I”, the timing of the II-th sound is indicated by “II”, and the heart noise is also shown in a simplified manner. FIG. 9 is a diagram showing detailed waveform examples of heart sounds when normal and when there is a disease, where a is a waveform example of normal heart sound information and b is aortic stenosis, AS ) Heart sound information waveform example, c is mitral regurgitation or mitral regurgitation (MR) heart sound information waveform example, d is aortic regurgitation (AR) heart sound Examples of information waveforms, e is an example waveform of heart sound information of mitral stenosis (MS), and f is an example of waveform information of heart sound information of patent ductus arteriosus (PDA). FIG. 8A schematically shows c in FIG. FIG. 8B schematically shows d in FIG.

In Figure 8A, systolic reflux for murmur W ₁₁ from being detected, mitral regurgitation is suspected as a disease between a first sound I and the II sound. In Figure 8B, heart murmur W ₁₂ diastolic irrigation like (reflux) from being detected, aortic regurgitation is suspected as a disease after a second sound II. In addition, since the way of hearing the heart noise varies depending on the mounting position of the heart sound sensor 22, when the information on the mounting position is included in the heart sound information, it is easier to estimate the disease. For example, since the general detection level of heart noise for each part of the heart is grasped in advance by the mounting position, the portion that generates heart noise from the detection level is narrowed down based on one or more current mounting positions. This makes it easier to estimate the disease. The scan control function 441 refers to, for example, a table in which a general detection level of heart noise for each part of the heart at each wearing position is stored, and compares it with the detection level of heart noise of the heart sound information actually detected. Then, narrow down the part that generates heart murmur and guess the disease. The presumed diseases are not limited to diseases related to heart valves, but also include heart diseases related to the myocardium.

  Returning to FIG. 7, the scan control function 441 then determines a time phase that is the center of imaging corresponding to the estimated disease (step S <b> 24). For example, when the mitral regurgitation is estimated in FIG. 8A, the scan control function 441 performs the first sound and the first sound with a large pressure difference between the pulmonary vein and the left ventricle in order to confirm the mitral valve deviation during regurgitation. The time phase that is the center of the shooting is determined to be the time phase that is the middle of the II sound or the time phase in which the mitral valve is deviated, that is, the time when the noise is greatest. In addition, when the aortic regurgitation is estimated in FIG. 8B, the scan control function 441 immediately after the second sound with a large pressure difference between the aorta and the left ventricle is used to confirm the deviation of the aortic valve during regurgitation. The time phase that is the center of imaging is determined as the time phase or the time phase in which the aortic valve is deviated, which is the time phase with the largest noise. The time phases corresponding to the first sound and the second sound, respectively, may be obtained from the first sound, the second sound, etc. detected immediately before the time phase is determined from the heart sound information. The average may be obtained from a plurality of detections. The scan control function 441 determines a general imaging time phase when a disease is not effectively estimated.

  Returning to FIG. 7, the scan control function 441 performs imaging (X-ray exposure and transmission X-ray detection) at the determined time phase (step S25). Since the minimum exposure necessary for photographing is sufficient, the amount of exposure can be reduced.

  Next, the image generation function 442 performs reconstruction based on the projection data obtained by imaging, and generates CT image data (step S26). The CT image data is converted into tomographic image data or three-dimensional image data of an arbitrary cross section based on an input operation received from the operator. Note that the processing after the reconstruction may be performed by the image generation function 542 of the workstation 50 based on the projection data.

  Next, the display control function 443 displays an image based on the CT image obtained by the reconstruction, the tomographic image data of an arbitrary cross section, and the three-dimensional image data on the display 42 (step S27). At this time, if a disease is estimated, the display control function 443 can display a cross-sectional image suitable for the estimated disease as an initial image. For example, when mitral regurgitation is presumed, a cross-sectional image in which the state of the mitral valve is easily understood can be displayed as an initial image. When the reconstruction is performed by the image generation function 542 of the workstation 50, the image display is performed by the display control function 543 of the workstation 50.

  Steps S <b> 21 to S <b> 25 shown in FIG. 7 are steps corresponding to the scan control function 441. Steps S21 to S25 are steps in which the scan control function 441 is realized by the processing circuit 44 reading and executing a program corresponding to the scan control function 441 from the memory 41.

  Step S <b> 26 illustrated in FIG. 7 is a step corresponding to the image generation function 442 or the image generation function 542. In step S26, the processing circuit 44 or the processing circuit 54 reads out and executes a program corresponding to the image generation function 442 or the image generation function 542 from the memory 41 or 51, thereby realizing the image generation function 442 or the image generation function 542. Step.

  Step S27 shown in FIG. 7 is a step corresponding to the display control function 443 or the display control function 543. In step S27, the processing circuit 44 or the processing circuit 54 reads out and executes a program corresponding to the display control function 443 or the display control function 543 from the memory 41 or 51, thereby realizing the display control function 443 or the display control function 543. Step.

  In addition, although embodiment applied to the X-ray CT apparatus was described, it can apply similarly to other medical image diagnostic apparatuses, such as a magnetic resonance imaging apparatus or an ultrasonic diagnostic apparatus.

  According to the present embodiment, a disease is estimated from heart sound information and the like, a time phase of imaging suitable for the disease is determined, and appropriate imaging of the heart can be performed. In addition, since the exposure to the minimum amount of X-rays necessary for imaging is sufficient, the amount of exposure can be reduced.

(Third embodiment)
In the above-described embodiment, the shooting time phase is determined first, and shooting is performed at the determined time phase. However, in the third embodiment, shooting is performed without specifying the time phase first. The reconstruction is performed based on the collected data at the time of photographing. The configuration example of the X-ray CT apparatus 1, the example of the mounting position of the heart sound sensor 22, and the configuration example of the workstation 50 are the same as those in FIGS.

  FIG. 10 is a flowchart showing an example of processing in the third embodiment. In the X-ray CT apparatus 1, during imaging of the heart, a specified period including one cycle of pulsation is specified without specifying the imaging time phase. The example of a process which performs imaging | photography is shown.

  In FIG. 10, the scan control function 441 acquires heart sound information from the subject P via the heart sound sensor 22 and the heart sound information acquisition circuit 23, and from the subject P via the electrode 24 and the electrocardiogram information acquisition circuit 25. While acquiring information, imaging (X-ray exposure and transmission X-ray detection) is performed (step S30-1), and data collection is performed (step S30-2). FIG. 11 is a diagram illustrating an example of collected data, including heart sound data corresponding to heart sound information, electrocardiogram data corresponding to electrocardiogram information, and projection data obtained by transmission X-ray detection. Yes. The heart sound data is included by the number of heart sound sensors 22 when a plurality of heart sound sensors 22 are provided. The heart sound data may or may not include information on the wearing position.

  Step S30 shown in FIG. 10 is a step corresponding to the scan control function 441. Step S30 is a step in which the scan control function 441 is realized by the processing circuit 44 reading and executing a program corresponding to the scan control function 441 from the memory 41.

  FIG. 12 is a flowchart showing an example of processing in the third embodiment, and is an example of processing in which reconstruction and image display are performed from collected data after shooting.

  In FIG. 12, the image generation function 442 acquires heart sound information and electrocardiogram information from the collected data (step S31).

  Next, the image generation function 442 determines the first sound, the second sound, etc., mainly using the heart sound information and the electrocardiographic information as the sub (step S32). The determination of the first sound, the second sound, and the like is performed in the same manner as described in FIGS. 5A to 5C.

  Next, the image generation function 442 estimates a disease from the heart sound information (step S33). Note that electrocardiogram information may be used in combination with disease estimation. The estimation of the disease is performed in the same manner as described in FIGS. 8A and 8B.

  Next, the image generation function 442 determines a time phase that is the center of reconstruction corresponding to the estimated disease (step S34). For example, as described above, when the mitral regurgitation is presumed, the scan control function 441 uses the first sound with a large pressure difference between the pulmonary vein and the left ventricle to confirm the mitral valve divergence during regurgitation. The time phase that is the center of imaging is determined as the time phase that is the middle of the sound and the second sound, or the time phase in which the mitral valve is deviated, which is the time phase with the highest noise. In addition, when aortic regurgitation is presumed, the scan control function 441 is a time phase immediately after the second sound in which the pressure difference between the aorta and the left ventricle is large in order to confirm the deviation of the aortic valve during regurgitation. Alternatively, the time phase that is the center of imaging is determined as the time phase in which the aortic valve is deviated, that is, the time phase with the largest noise. The time phases corresponding to the first sound and the second sound, respectively, may be obtained from the first sound, the second sound, etc. detected immediately before the time phase is determined from the heart sound information. The average may be obtained from a plurality of detections. The image generation function 442 determines a general reconstruction time when a disease is not effectively estimated.

  Next, the image generation function 442 performs reconstruction based on the projection data included in the collected data at the determined time phase, and generates CT image data (step S35). The CT image data is converted into tomographic image data or three-dimensional image data of an arbitrary cross section based on an input operation received from the operator.

  Next, the display control function 443 displays an image based on the CT image obtained by the reconstruction, the tomographic image data of an arbitrary cross section, and the three-dimensional image data on the display 42 (step S36). At this time, if a disease is estimated, the display control function 443 can display a cross-sectional image suitable for the estimated disease as an initial image.

  The acquisition to reconstruction process shown in the flowchart of FIG. 12 may be performed by the image generation function 542 of the workstation 50, and the image display may be performed by the display control function 543.

  Steps S31 to S35 shown in FIG. 12 are steps corresponding to the image generation function 442 or the image generation function 542. In steps S31 to S35, when the processing circuit 44 or the processing circuit 54 reads out and executes a program corresponding to the image generation function 442 or the image generation function 542 from the memory 41 or the memory 51, the image generation function 442 or the image generation function 542 It is a step that is realized.

  Step S36 shown in FIG. 12 is a step corresponding to the display control function 443 or the display control function 543. In step S36, the display control function 443 or the display control function 543 is realized by the processing circuit 44 or the processing circuit 54 reading and executing a program corresponding to the display control function 443 or the display control function 543 from the memory 41 or the memory 51. Step.

  According to the present embodiment, a disease is estimated from heart sound information and the like, a reconstruction phase suitable for the disease is determined, and appropriate imaging of the heart can be performed.

  In the third embodiment, the estimation of the disease is performed prior to the reconstruction based on the collected data. However, the reconstruction is determined based on the heart sound information and the electrocardiogram information without estimating the disease. You may make it reconfigure | reconstruct in the time phase used as the center of. For example, for the reconstruction of the mitral valve, the time phase that is the center of the reconstruction is preferably determined to be a time phase intermediate between the first sound and the second sound that are in the middle systole. The reconstruction of the aortic valve is preferably determined at a time phase between the second sound and the first sound, which is the middle diastole (around 1/3 from the second sound).

  According to at least one embodiment described above, appropriate imaging of the heart can be performed.

  Although several embodiments of the present invention 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, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 22 Heart sound sensor 23 Heart sound information acquisition circuit 24 Electrode 25 Electrocardiogram information acquisition circuit 40 Console apparatus 44 Processing circuit 441 Scan control function 442 Image generation function 50 Workstation 54 Processing circuit 542 Image generation function 543 Display control function

Claims (9)

Acquiring a heart sound information and electrocardiogram information from a subject, and specifying a phase of imaging or reconstruction from the heart sound information and the electrocardiogram information;
A medical image diagnostic apparatus comprising: a processing unit configured to perform imaging of the subject based on the time phase of the imaging or to perform reconstruction of the subject based on the time phase of the reconstruction. An estimation unit for estimating a disease of the subject from the heart sound information;
The specifying unit specifies a time phase of imaging or reconstruction corresponding to the disease;
The medical image diagnostic apparatus according to claim 1. Obtaining a heart sound information from a subject, and estimating a disease of the subject from the heart sound information;
A specifying unit for specifying a time phase of imaging or reconstruction corresponding to the disease;
A medical image diagnostic apparatus comprising: a processing unit configured to perform imaging of the subject based on the time phase of the imaging or to perform reconstruction of the subject based on the time phase of the reconstruction. The estimation unit acquires heart sound information from a plurality of locations of the subject, and classifies heart sounds based on the plurality of locations.
The medical image diagnostic apparatus according to claim 3. The processing unit displays a diagnostic image corresponding to the disease on a display unit.
The medical image diagnostic apparatus according to any one of claims 2 to 4. A specifying unit for specifying a time phase of reconstruction from heart sound information and electrocardiogram information acquired from a subject;
A medical image processing apparatus comprising: a processing unit configured to reconstruct the subject based on the time phase of the reconstruction. An estimation unit that estimates a disease of the subject from heart sound information acquired from the subject;
A specifying unit for specifying a time phase of reconstruction corresponding to the disease;
A medical image processing apparatus comprising: a processing unit configured to reconstruct the subject based on the time phase of the reconstruction. Obtain heart sound information and electrocardiogram information from the subject,
Identify the phase of imaging or reconstruction from the heart sound information and the electrocardiogram information,
Perform imaging of the subject based on the time phase of the imaging, or reconfigure the subject based on the time phase of the reconstruction,
A program that causes a computer to execute each process. Obtain heart sound information from the subject,
Inferring the subject's disease from the heart sound information,
Identify the phase of imaging or reconstruction corresponding to the disease,
Perform imaging of the subject based on the time phase of the imaging, or reconfigure the subject based on the time phase of the reconstruction,
A program that causes a computer to execute each process.

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