JP2019084037A - Ultrasound diagnostic apparatus and control program - Google Patents

Abstract

To make more efficient ultrasound imaging diagnosis which uses volume data.SOLUTION: An ultrasound diagnostic apparatus according to the embodiment comprises: an image data generation unit; a recording control unit, a volume data generation unit, a rendering processing unit, and a display control unit. The image data generation unit repeatedly generates image data based on reception data collected by receiving ultrasound waves. The recording control unit stores the image data in memory and deletes the image data in chronological order each time the total quantity of the image data satisfies a predetermined condition. The volume data generation unit generates volume data each time the image data generation unit generates the image data corresponding to at least one time phase. The rendering processing unit sequentially applies a rendering process to the volume data to generate a rendering image. The display control unit sequentially displays the rendering image on a display unit.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to an ultrasonic diagnostic apparatus and a control program.

  The ultrasonic diagnostic apparatus is an apparatus that generates image data based on received data acquired by receiving ultrasonic waves via an ultrasonic probe. The generated image data is, for example, two-dimensional image data corresponding to a two-dimensional area of the subject, or three-dimensional image data (volume data) corresponding to a three-dimensional area of the subject. When the image data to be generated is volume data, rendering processing such as volume rendering or surface rendering is performed on the volume data, for example, to generate rendering image data. An operator such as a doctor visually recognizes the rendering image based on the generated rendering image data, and confirms whether or not the expected volume data has been generated.

  Here, in the process of generating volume data, for example, an ultrasonic image data generation process of generating ultrasonic image data corresponding to each time phase, and a volume using ultrasonic image data corresponding to a plurality of time phases. It is divided into volume data generation processing for generating data. Conventionally, for example, volume data generation processing has been started after completion of generation processing of ultrasound image data corresponding to a plurality of time phases. That is, the ultrasound image data generation process and the volume data generation process are performed serially.

  However, with the above generation method, an unacceptable time difference occurs between the collection timing of reception data by ultrasonic waves and the display timing of volume data, and it can not be efficiently confirmed whether or not the expected volume data can be generated. there were.

JP, 2010-99195, A

  An object of the present embodiment is to streamline ultrasound image diagnosis using volume data.

  According to the embodiment, the ultrasonic diagnostic apparatus includes an image data generation unit, a recording control unit, a volume data generation unit, a rendering processing unit, and a display control unit. The image data generation unit repeatedly generates image data based on reception data collected by receiving an ultrasonic wave via the ultrasonic probe. A recording control unit records the image data in a memory, and a total amount of the image data recorded in the memory or a time when the oldest image data recorded in the memory is recorded in the memory Whenever the predetermined condition is satisfied, the image data recorded in the memory is deleted in order of age. Each time the image data generation unit generates the image data corresponding to at least one phase, the volume data generation unit uses the image data corresponding to a plurality of time phases recorded in the memory. Generate volume data. The rendering processing unit sequentially performs a rendering process on the generated volume data to generate a rendering image. The display control unit causes the display unit to sequentially display the generated rendering image.

FIG. 1 is a view showing the configuration of an ultrasonic diagnostic apparatus according to the embodiment. FIG. 2 is a flowchart showing an example of the operation of the control circuit when the ultrasonic diagnostic apparatus according to the embodiment performs input and output with respect to the internal memory. FIG. 3 is a flowchart showing an example of the operation of the control circuit when the ultrasound diagnostic apparatus according to the embodiment generates volume data with reference to ultrasound image data recorded in the internal memory. FIG. 4 is a diagram for explaining a method of generating volume data using ultrasonic image data recorded in the internal memory by the control circuit according to the embodiment. FIG. 5 is a view showing a display mode of a rendered image displayed on the display circuit according to the embodiment. FIG. 6 is a view showing a display mode of a rendering image displayed on the display circuit according to the embodiment. FIG. 7 is a view showing a display mode of a rendering image displayed on the display circuit according to the embodiment. FIG. 8 is a view showing a display mode of a rendering image displayed on a display circuit according to another embodiment.

  Embodiments will be described below with reference to the drawings.

  An ultrasonic diagnostic apparatus 1 according to the present embodiment will be described with reference to the block diagram of FIG.

  As shown in FIG. 1, the ultrasonic diagnostic apparatus 1 includes an apparatus main body 10, an ultrasonic probe 70, a display device 50, and an input device 60. The device body 10 is connected to an external device 40 via the network 100. In addition, the device body 10 is connected to the position sensor system 30, the display device 50, and the input device 60.

  The position sensor system 30 is a system for acquiring three-dimensional position information of the ultrasound probe 70 and the ultrasound image. Position sensor system 30 includes position sensor 31 and position detection device 32.

  The position sensor system 30 acquires three-dimensional position information of the ultrasonic probe 70 by, for example, attaching a magnetic sensor, an infrared sensor, a target for an infrared camera, or the like to the ultrasonic probe 70 as the position sensor 31. Alternatively, a gyro sensor (angular velocity sensor) may be built in the ultrasonic probe 70, and three-dimensional positional information of the ultrasonic probe 70 may be acquired by the gyro sensor. In addition, the position sensor system 30 may acquire three-dimensional position information of the ultrasonic probe 70 by photographing the ultrasonic probe 70 with a camera and performing image recognition processing on the photographed image. Further, the position sensor system 30 may hold the ultrasonic probe 70 by the robot arm, and acquire the position of the three-dimensional space of the robot arm as position information of the ultrasonic probe 70.

  Below, the case where position sensor system 30 acquires the positional information on the position of ultrasonic probe 70 using a magnetic sensor is explained to an example. Specifically, position sensor system 30 further includes a magnetic generator (not shown) having, for example, a magnetic generation coil or the like. The magnetic generator generates a magnetic field outward from the magnetic generator itself. In the generated magnetic field, a magnetic field space in which position accuracy is guaranteed is defined. Therefore, the arrangement of the magnetic generator may be arranged so that the living body to be inspected is contained in the magnetic field space whose position accuracy is guaranteed. The position sensor 31 mounted on the ultrasonic probe 70 detects the strength and inclination of the three-dimensional magnetic field formed by the magnetic generator. Thereby, the position and direction of the ultrasonic probe 70 can be acquired. The position sensor 31 outputs the detected strength and inclination of the magnetic field to the position detection device 32.

  The position detection device 32 detects, for example, the position of the ultrasonic probe 70 in a three-dimensional space with the predetermined position as the origin (the position (x, y, z) and rotation angles (θx, θy, θz)) are calculated. At this time, the predetermined position is, for example, a position where the magnetic generator is disposed. The position detection device 32 transmits position information on the calculated position (x, y, z, θx, θy, θz) to the device body 10.

  The positional information can be added to the ultrasonic image data by correlating the positional information acquired as described above with the ultrasonic image data of the ultrasonic waves transmitted and received from the ultrasonic probe 70 by time synchronization or the like.

  The ultrasonic probe 70 has a plurality of piezoelectric vibrators, matching layers provided on the piezoelectric vibrators, and a backing material that prevents the propagation of ultrasonic waves rearward from the piezoelectric vibrators. The ultrasonic probe 70 is detachably connected to the apparatus main body 10. The plurality of piezoelectric transducers generate ultrasonic waves based on drive signals supplied from the ultrasonic wave transmission circuit 11 of the apparatus main body 10. Further, in the ultrasonic probe 70, a button to be pressed in the case of offset processing described later, freezing of an ultrasonic image, or the like may be arranged.

  When an ultrasonic wave is transmitted from the ultrasonic probe 70 to the subject P, the transmitted ultrasonic wave is reflected one after another by the discontinuous surface of the acoustic impedance in the body tissue of the subject P, and a reflected wave signal (echo signal) Are received by the plurality of piezoelectric transducers that the ultrasonic probe 70 has. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuity where the ultrasound is reflected. The reflected wave signal when the transmitted ultrasonic pulse is reflected by the moving blood flow or the surface such as the heart wall depends on the velocity component of the moving body with respect to the ultrasonic transmission direction by the Doppler effect. Receive frequency shift. The ultrasound probe 70 receives a reflected wave signal from the subject P and converts it into an electrical signal. In the present embodiment, the ultrasonic probe 70 is, for example, a 1D array probe in which a plurality of piezoelectric transducers are arranged along a predetermined direction, and a 2D array probe in which a plurality of piezoelectric transducers are arranged in a two-dimensional matrix. Or a mechanical 4D probe or the like capable of executing ultrasonic scanning while mechanically scanning the piezoelectric transducer array in the direction orthogonal to the arrangement direction.

  The apparatus main body 10 shown in FIG. 1 is an apparatus that generates an ultrasonic image based on the reflected wave signal received by the ultrasonic probe 70. As shown in FIG. 1, the device body 10 includes an ultrasonic wave transmission circuit 11, an ultrasonic wave reception circuit 12, a B mode processing circuit 13, a Doppler processing circuit 14, an image generation circuit 15, an internal recording circuit 17, and an image memory 18 (cine memory , An image database 19, an input interface 20, a communication interface 21 and a control circuit 22.

  The ultrasound transmission circuit 11 is a processor that supplies a drive signal to the ultrasound probe 70. The ultrasound transmission circuit 11 is realized by, for example, a trigger generation circuit, a delay circuit, and a pulser circuit. The trigger generation circuit repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency under the control of the control circuit 22. The delay circuit delays the delay time of each piezoelectric transducer necessary to focus the ultrasonic waves generated from the ultrasonic probe 70 in the form of a beam to determine the transmission directivity, for each rate pulse generated by the trigger generation circuit. Give against. The pulser circuit applies a drive signal (drive pulse) to the ultrasonic probe 70 at the timing based on the rate pulse under the control of the control circuit 22. By changing the delay time given to each rate pulse by the delay circuit, the transmission direction from the surface of the piezoelectric vibrator can be arbitrarily adjusted.

  The ultrasound receiving circuit 12 is a processor that performs various processes on the reflected wave signal received by the ultrasound probe 70 and generates a received signal. The ultrasonic wave receiving circuit 12 is realized by, for example, an amplifier circuit, an A / D converter, a reception delay circuit, an adder, and the like. The amplifier circuit amplifies the reflected wave signal received by the ultrasonic probe 70 for each channel to perform gain correction processing. The A / D converter converts the gain-corrected reflected wave signal into a digital signal. The reception delay circuit gives the digital signal the delay time necessary to determine the reception directivity. The adder adds a plurality of digital signals given delay times. The addition process of the adder generates a reception signal in which the reflection component from the direction according to the reception directivity is emphasized.

  The B-mode processing circuit 13 is a processor that generates B-mode data based on the reception signal received from the ultrasound receiving circuit 12. B-mode processing circuit 13 performs envelope detection processing, logarithmic amplification processing, and the like on the reception signal received from ultrasonic wave reception circuit 12, and data (B-mode data) in which signal intensity is expressed by brightness of luminance Generate The generated B mode data is recorded in a RAW data memory (not shown) as B mode RAW data on a two-dimensional ultrasonic scan line.

  The Doppler processing circuit 14 is a processor that generates a Doppler waveform and Doppler data based on the reception signal received from the ultrasound reception circuit 12. The Doppler processing circuit 14 extracts a blood flow signal from the received signal, generates a Doppler waveform from the extracted blood flow signal, and extracts data such as average velocity, dispersion, and power from the blood flow signal at multiple points. Generate (Doppler data). The generated Doppler data is recorded in a RAW data memory (not shown) as Doppler RAW data on a two-dimensional ultrasonic scanning line.

  The image generation circuit 15 is a processor capable of generating various types of ultrasonic image data based on data generated by the B-mode processing circuit 13 and the Doppler processing circuit 14. The image generation circuit 15 includes an internal memory (not shown). The internal memory is an example of the memory described in the claims. When the ultrasonic probe 70 to which the position sensor 31 is attached is a one-dimensional array probe, the image generation circuit 15 detects the position of, for example, B-mode RAW data or Doppler RAW data recorded in the RAW data memory. The positional information of the ultrasonic probe 70 calculated by the device 32 is correlated. In addition, the image generation circuit 15 generates two-dimensional image data (hereinafter referred to as frame data) composed of pixels by executing RAW-pixel conversion. Frame data is generated in units of frames in accordance with a preset frame rate. The position data of the ultrasound probe 70 calculated by the position detection device 32 is associated with the frame data. The generated frame data is recorded in the internal memory in frame units.

  Further, the image generation circuit 15 executes interpolation processing or the like taking spatial position information into consideration with respect to the generated frame data, whereby three-dimensional image data (hereinafter referred to as volume data) configured of voxels in a desired range Create the The image generation circuit 15 generates volume data by performing RAW-voxel conversion including interpolation processing in which spatial position information is added to B-mode RAW data recorded in the RAW data memory. May be

  Similarly, in the case where the ultrasonic probe 70 to which the position sensor 31 is attached is a mechanical four-dimensional probe (three-dimensional mechanical swing type probe) or a two-dimensional array probe, two-dimensional RAW data, two-dimensional image data, And positional information is matched with three-dimensional image data.

  Further, the image generation circuit 15 associates the position information of the ultrasonic probe 70 calculated by the position detection device 32 with the M-mode image and the spectral Doppler image acquired at a desired scanning position. In addition, the image generation circuit 15 is configured to scan image quality conditions (field angle, view depth, view angle, preset, frequency, image processing conditions, etc.), scan mode information, measurement image and measurement result, and application information and image. The position information of the ultrasonic probe 70 calculated by the position detection device 32 is associated with

  Further, the image generation circuit 15 performs, for example, rendering processing on various volume data to generate rendering image data. The image generation circuit 15 performs MPR (Multi Planar Reconstruction) processing on various volume data to generate MPR image data representing a predetermined cross-sectional image (MPR image) in the volume data. Further, the image generation circuit 15 performs Curved MPR (Multi Planar Reconstruction) processing on the generated various volume data to generate curved cross-sectional image data representing a predetermined curved cross-sectional image in the volume data.

  In addition, the image generation circuit 15 may execute various processes such as dynamic range, brightness (brightness), contrast, γ curve correction, and RGB conversion on the generated various ultrasonic image data.

  The image generation circuit 15 generates a user interface (GUI: Graphical User Interface) for the operator (for example, an operator) to input various instructions through the input interface 20, and causes the display device 50 to display the GUI. It is also good. As the display device 50, for example, a CRT display, a liquid crystal display, an organic EL display, an LED display, a plasma display, or any other display known in the art can be appropriately used. The display device 50 has, for example, a function of a notification unit.

  The internal recording circuit 17 includes, for example, a magnetic or optical recording medium, or a recording medium readable by a processor such as a semiconductor memory. The internal recording circuit 17 stores a control program for realizing ultrasonic wave transmission and reception, a control program for performing image processing, a control program for performing display processing, and the like. In addition, the internal recording circuit 17 records a control program for realizing various functions according to the present embodiment. In addition, the internal recording circuit 17 includes diagnostic information (for example, patient ID, doctor's findings, etc.), a diagnostic protocol, a body mark generation program, and a conversion table in which the range of color data used for visualization is preset for each diagnostic site. The data group of is recorded. In addition, the internal recording circuit 17 may record an anatomical drawing, for example, an atlas, regarding the structure of an organ in a living body.

  Further, the internal recording circuit 17 records the volume data and the rendering image data generated by the image generation circuit 15 in accordance with the recording operation input via the input interface 20. The internal recording circuit 17 may record the volume data generated by the image generation circuit 15 and the rendering image data, including the operation order and the operation time, in accordance with the recording operation input via the input interface 20. . The internal recording circuit 17 can also transfer the recorded data to an external device via the communication interface 21.

  The image memory 18 has, for example, a magnetic or optical recording medium, or a recording medium readable by a processor such as a semiconductor memory. The image memory 18 stores image data corresponding to a plurality of frames immediately before the freeze operation input via the input interface 20. The image data stored in the image memory 18 is, for example, continuously displayed (cine display).

  The image database 19 records image data transferred from the external device 40. For example, the image database 19 acquires, from the external device 40, past image data on the same patient acquired in past examinations and records the same. Past image data includes ultrasound image data, computed tomography (CT) image data, magnetic resonance (MR) image data, PET (Positron Emission Tomography) -CT image data, PET-MR image data, and X-ray image data. Be Also, past image data is recorded as, for example, three-dimensional volume data and rendering image data.

  The image database 19 may store desired image data by reading image data recorded on a recording medium such as an MO, a CD-R, and a DVD.

  The input interface 20 receives various instructions from the operator via the input device 60. The input device 60 includes, for example, a mouse, a keyboard, a panel switch, a slider switch, a dial switch, a trackball, a rotary encoder, a rotary switch, a lever, an operation panel, and a touch command screen (TCS).

  The input interface 20 is connected to the control circuit 22 via, for example, a bus, converts an operation instruction input from the operator into an electrical signal, and outputs the electrical signal to the control circuit 22. In the present specification, the input interface 20 is not limited to one connected with physical operation parts such as a mouse and a keyboard. For example, processing of an electrical signal that receives an electrical signal corresponding to an operation instruction input from an external input device provided separately from the ultrasonic diagnostic apparatus 1 as a wireless signal and outputs the electrical signal to the control circuit 22 A circuit is also included in the example of the input interface 20.

  The communication interface 21 is connected to the position sensor system 30, for example, wirelessly, and receives the position information transmitted from the position detection device 32. Further, the communication interface 21 is connected to the external device 40 via the network 500 or the like, and performs data communication with the external device 40. The external apparatus 40 is, for example, a database of a PACS (Picture Archiving and Communication System) which is a system for managing data of various medical images, a database of an electronic medical record system for managing electronic medical records attached with medical images, and the like. Further, the external device 40 is, for example, various medical images other than the ultrasonic diagnostic device 1 according to the present embodiment, such as an X-ray CT device, an MRI (Magnetic Resonance Imaging) device, a nuclear medicine diagnostic device, and an X-ray diagnostic device. It is a diagnostic device. The standard of communication with the external device 40 may be any standard, for example, DICOM.

  The control circuit 22 is, for example, a processor that functions as a center of the ultrasonic diagnostic apparatus 1. The control circuit 22 implements the function corresponding to the operation program by executing the operation program recorded in the internal recording circuit 17. Specifically, the control circuit 22 has a recording control function 221, an image processing function 223, a display control function 225, and a system control function 227.

  The recording control function 221 is a function of managing ultrasound image data recorded in the internal memory of the image generation circuit 15. When the recording control function 221 is executed, the control circuit 22 refers to the internal memory, for example, the total amount of ultrasonic image data recorded in the internal memory, or the oldest ultrasonic image data recorded in the internal memory It is determined whether the time recorded in the memory satisfies a predetermined condition. The total amount of ultrasound image data is represented, for example, by the data volume of ultrasound image data. In addition, the total amount of ultrasound image data is represented by, for example, time based on a predetermined generation rate of ultrasound image data. Specifically, the total amount of ultrasound image data is expressed as, for example, “10 seconds of ultrasound image data generated at 10 frames / second”. In addition, the total amount of ultrasound image data is the number of frames that are units that configure two-dimensional ultrasound image data (hereinafter referred to as the number of frames) and the number of volumes that are units that configure three-dimensional ultrasound image data. (Hereinafter referred to as the number of volumes) or the like.

  Specifically, for example, the control circuit 22 determines whether the total amount of ultrasound image data recorded in the internal memory has reached a predetermined upper limit, or most of the ultrasound image data recorded in the internal memory. It is determined whether the time during which old ultrasound image data is recorded in the internal memory has reached a predetermined upper limit.

  The control circuit 22 satisfies the predetermined condition that the total amount of ultrasonic image data recorded in the internal memory or the time when the oldest ultrasonic image data recorded in the internal memory is recorded in the memory When it is determined that, for example, the ultrasonic image data recorded in the internal memory is deleted in order of time when the internal image is recorded in the internal memory.

  The image processing function 223 is a function of generating volume data using ultrasonic image data corresponding to a predetermined number of time phases recorded in an internal memory included in the image generation circuit 15. When the image processing function 223 is executed, for example, the control circuit 22 controls the image generation circuit 15 each time ultrasonic image data corresponding to the first number of time phases is generated, and refers to the internal memory. And acquiring ultrasound image data corresponding to the second number of time phases. The ultrasound image data corresponding to the second number of time phases acquired from the internal memory preferably includes the ultrasound image data most recently recorded in the internal memory. The ultrasound image data corresponding to the second number of time phases acquired from the internal memory is preferably ultrasound image data corresponding to the continuous second number of time phases. The first number is, for example, one or more, and the second number is, for example, two or more (plural). The ultrasound image data corresponding to the one time phase is, for example, ultrasound image data corresponding to one frame, and the ultrasound image data corresponding to the n (n is an integer of 2 or more) time phase is, for example, n The ultrasound image data corresponding to the frame of. The control circuit 22 generates volume data based on the acquired ultrasound image data corresponding to the second number of time phases and the position information of the ultrasound probe 70 associated with each ultrasound image data. The control circuit 22 performs predetermined rendering processing on the generated volume data to generate rendering image data.

  The display control function 225 is a function of displaying a rendered image based on the rendered image data generated by the image processing function 223. When the display control function 225 is executed, the control circuit 22 causes the display device 50 to display a rendering image based on the rendering image data generated by the image processing function 223.

  The system control function 227 is a function that controls basic operations such as input / output of the ultrasonic diagnostic apparatus 1. When the system control function 227 is executed, the control circuit 22 receives inputs of various scan modes via, for example, the input interface 20. The control circuit 22 executes various ultrasonic scans in accordance with the received scan mode to generate various ultrasonic image data. Specifically, for example, when the scan mode is the B mode, the control circuit 22 controls the ultrasonic wave transmission circuit 11, the ultrasonic wave reception circuit 12, the B mode processing circuit 13, and the image generation circuit 15 in frame units. Generate B-mode image data. Specifically, for example, when the received scan mode is the Doppler mode, the control circuit 22 controls the ultrasonic wave transmission circuit 11, the ultrasonic wave reception circuit 12, the Doppler processing circuit 14, and the image generation circuit 15, and the frame unit To generate Doppler image data.

  The recording control function 221, the image processing function 223, the display control function 225, and the system control function 227 may be incorporated as a control program, or the control circuit 22 itself or a circuit that the control circuit 22 can refer to the apparatus main body 10. A dedicated hardware circuit capable of performing each function may be incorporated.

  Next, the operation of the ultrasound diagnostic apparatus 1 according to the first embodiment will be described with reference to the flowcharts of FIGS. 2 and 3.

  FIG. 2 is a flowchart showing an example of the operation of the control circuit 22 when the ultrasonic diagnostic apparatus 1 according to the present embodiment performs input and output with respect to the internal memory. FIG. 3 is a flowchart showing an example of the operation of the control circuit 22 when volume data is generated with reference to ultrasound image data recorded in the internal memory by the ultrasound diagnostic apparatus 1 according to the present embodiment.

  First, with reference to FIG. 2, the operation of the control circuit 22 when the ultrasonic diagnostic apparatus 1 according to the embodiment performs input and output with respect to the internal memory will be described. In the following description, ultrasound scanning is performed in B mode. Further, ultrasound image data corresponding to one frame is generated from ultrasound image data generated from a reflected wave signal obtained by performing B-mode scanning of a two-dimensional scanning range once using the ultrasound probe 70 (B-mode image It shall be treated as data). The ultrasonic scan is performed by moving, that is, sweeping, the ultrasonic probe 70 in a predetermined direction at a constant speed in a state where the ultrasonic probe 70 is in contact with the subject P. At this time, positional information of the ultrasonic probe 70 associated with each B-mode image data represents different positions. The ultrasonic probe 70 may be moved by any method as long as it is moved in a predetermined direction at a constant speed. For example, the ultrasonic probe 70 is manually moved while being held directly by the operator. Further, the ultrasonic probe 70 is automatically fixed by, for example, a movement instruction for moving the ultrasonic probe 70 via a lever or the like included in the input interface 20 while being fixed to a mechanical arm. It may be moved by In addition, B-mode image data generated during ultrasound scanning is repeatedly generated in frame units according to a preset frame rate, and is recorded in an internal memory included in the image generation circuit 15. Further, it is assumed that the first number set in advance is 1 and the second number is 4. Further, it is assumed that the predetermined condition is that the number of frames of B-mode image data recorded in the internal memory reaches a predetermined upper limit. The first number may be two or more. In addition, the second number can be set to any value as long as it is 1 or more.

  In FIG. 2, when the control circuit 22 receives an instruction to start the B mode via the input interface 20, the control circuit 22 receives the ultrasonic wave transmission circuit 11, the ultrasonic wave reception circuit 12, the B mode processing circuit 13, and the image generation. The circuit 15 is controlled to start an ultrasonic scan (step SA1).

  The control circuit 22 generates B-mode image data corresponding to one frame associated with the positional information of the ultrasonic probe 70 based on the reflected wave received by the ultrasonic receiving circuit 12 (step SA2).

  The control circuit 22 records B mode image data corresponding to the generated one frame in the internal memory (step SA3).

  The control circuit 22 determines whether a stop instruction to stop the ultrasonic scan has been input (step SA4).

  When the control circuit 22 determines that the stop instruction to stop the ultrasonic scan is not input (No in step SA4), for example, the number of frames of the B mode image data recorded in the internal memory becomes a predetermined upper limit. It is determined whether it has reached (step SA5).

  If the control circuit 22 determines that the number of frames of B mode image data recorded in the internal memory has reached a predetermined upper limit (Yes in step SA5), the oldest B mode image data is deleted from the internal memory (Step SA6). The oldest B mode image data is, for example, the oldest ultrasonic image data recorded at the internal memory.

  After deleting the oldest B-mode image data from the internal memory, the control circuit 22 executes the processing from step SA2 to step SA4.

  When the control circuit 22 determines that the number of frames of B-mode image data recorded in the internal memory has not reached the predetermined upper limit (No in step SA5), the process from step SA2 to step SA4 is performed. Run.

  As described above, the control circuit 22 keeps the number of frames of B-mode image data recorded in the internal memory equal to or less than a predetermined upper limit value every time one frame of B-mode image data is generated during B-mode scanning.

  Next, with reference to FIG. 3, the operation of the control circuit 22 when the ultrasound diagnostic apparatus 1 generates volume data with reference to ultrasound image data (B mode image data) recorded in the internal memory will be described. Do. In the following description, it is assumed that the number of frames of B-mode image data recorded in the internal memory before the ultrasound scan is started is zero.

  The control circuit 22 executes the image processing function 223 when the ultrasound scan is started. By executing the image processing function 223, the control circuit 22 refers to the internal memory and additionally records B mode image data corresponding to the first number of time phases and B mode image data corresponding to one time phase in the internal memory. It is determined whether or not it is (step SB1).

  When the control circuit 22 determines that the B mode image data corresponding to the first number of time phases is additionally recorded in the internal memory (Yes in step SA1), the latest second number recorded in the internal memory Volume data is generated using B-mode image data corresponding to the time phase of B, that is, B-mode image data corresponding to the four-time phase (step SB2).

  FIG. 4 is a diagram for explaining an example of a method of generating volume data using ultrasonic image data (B-mode image data) recorded in the internal memory by the control circuit 22 in the present embodiment. As shown in FIG. 4, the control circuit 22 executes the recording control function 221 and the system control function 227 and, for example, in frame units, frame data F1, F2, F3, F4, F5, F6, and F7. Generate in order. The control circuit 22 records the generated B-mode image data in frame units in the internal memory each time one frame is generated.

  On the other hand, the control circuit 22 executes the image processing function 223, and whenever B mode image data corresponding to the first number of time phases, that is, B mode image data corresponding to one frame is recorded in the internal memory. The volume data is generated using B-mode image data corresponding to the latest second number of time phases recorded in the internal memory, that is, B-mode image data corresponding to the fourth phase. For example, as shown in FIG. 4, the control circuit 22 controls the volume data to be volume data V1, V2, V3, each time ultrasound image data is generated in the order of frame data F4, F5, F6, and F7. And V4 sequentially. Specifically, when the frame data F4 is recorded in the internal memory, the control circuit 22 generates volume data V1 using the frame data F1, F2, F3, and F4. When the frame data F5 is recorded in the internal memory, the control circuit 22 generates volume data V2 using the frame data F2, F3, F4, and F5. When the frame data F6 is recorded in the internal memory, the control circuit 22 generates volume data V3 using the frame data F3, F4, F5, and F6. When the frame data F7 is recorded in the internal memory, the control circuit 22 generates volume data V4 using the frame data F4, F5, F6, and F7.

  When the number of frames of B-mode image data recorded in the internal memory does not reach the second number, the control circuit 22 uses volume data of all B-mode image data recorded in the internal memory. May be generated. In addition, when the B mode image data corresponding to the number of time phases exceeding the first number is additionally recorded in the internal memory, the control circuit 22 outputs the B mode image data recorded in the internal memory. And generating volume data from the latest B-mode image data using the B-mode image data corresponding to the second number of time phases. At this time, the control circuit 22 skips the volume data generation process for frame data corresponding to the time phase of the excess number exceeding at least the first number. That is, the control circuit 22 generates volume data each time frame data corresponding to at least two phases is generated so that the latest frame data is included in the volume data. Specifically, since the first number is 1, for example, when frame data corresponding to three time phases are additionally recorded, the control circuit 22 performs volume control on frame data corresponding to two time phases. Skip the data generation process. That is, when the control circuit 22 refers to the internal memory for the first time after generating the volume data V1 shown in FIG. 4, for example, frame data F5, F6, and F7 corresponding to three time phases are stored in the internal memory. If it is additionally recorded, volume data V4 is generated so as to include frame data F4, F5, F6, and F7 corresponding to the latest four time phases. At this time, the control circuit 22 does not generate the volume data V2 and the volume data V3 shown in FIG. Further, the control circuit 22 does not use the frame data F2 and F3 for generating the volume data V4. Such processing is particularly effective, for example, when the rate of generation of frame data exceeds the rate of generation of volume data.

  After generating the volume data, the control circuit 22 performs predetermined rendering processing on the generated volume data to generate rendering image data (step SB3).

  The control circuit 22 displays a rendering image based on the generated rendering image data on the display device 50 (step SB4).

  The control circuit 22 determines whether a stop instruction to stop the ultrasonic scan has been input (step SB5).

  If the control circuit 22 determines that the stop instruction to stop the ultrasound scan is not input (No in step SB5), the control circuit 22 executes the processing from step SB1 to step SB5 again.

  As described above, the control circuit 22 generates volume data each time B-mode image data corresponding to at least a first number of time phases, that is, B-mode image data corresponding to one frame is generated. Furthermore, the control circuit 22 performs predetermined rendering processing on the generated volume data, generates rendering image data, and displays a rendering image based on the generated rendering image data on the display device 50.

  FIG. 5 is a diagram illustrating an example of a display mode of a rendering image displayed on the display device 50 according to the present embodiment. The arrow A1 shown in FIG. 5 represents the direction in which the ultrasonic probe 70 is swept. According to FIG. 5, the rendered image is synchronized with the ultrasonic probe 70 sweeping in the direction of A1, the rendered image VR11 (time t = t1), VR12 (time t = t2), VR13 (time t). The display device 50 sequentially displays in the order of: t3), VR14 (point t = t4), VR15 (point t = t5), and VR16 (point t = t6). For example, until time t = t3, since the number of frames of ultrasound image data used to generate volume data is less than or equal to the second number, the width of the rendered image in the direction of A1 monotonously increases. This allows the operator to view the rendered image during the sweep even if the sweep of the ultrasound probe is not completed.

  On the other hand, between the time point t = t4 and the time point t = t6, the number of frames of B-mode image data recorded in the internal memory exceeds the second number, so The width is constant. That is, of the rendered images, the area corresponding to the B-mode image data recorded in the internal memory at the most recent time is displayed, and at the same time the area corresponding to the B-mode image data recorded at the oldest time It will be displayed. As a result, the number of frames of B-mode image data used for volume data generation can be limited, and the volume data generation time during ultrasonic scanning can be shortened.

  The control circuit 22 may gradually lower the luminance of the rendering image to be displayed from the area corresponding to the old B-mode image data and may finally disappear. At this time, for example, the control circuit 22 is a part of the generated volume data, and among the frame data used to generate the volume data, a part of the luminance corresponding to the frame data corresponding to the old time phase. The volume data is lowered, and rendering processing is performed on the partially reduced volume data to generate rendered image data. The control circuit 22 displays a rendering image based on the generated rendering image data on the display device 50. FIG. 6 is a diagram illustrating an example of a display mode of a rendering image displayed on the display device 50 according to the present embodiment. The arrow A1 shown in FIG. 6 represents the direction in which the ultrasonic probe 70 is swept. According to FIG. 6, the rendered image is synchronized with the ultrasound probe 70 sweeping in the direction of A1, and the rendered images VR21 (t = t1), VR22 (t = t2), VR23 (t = t3). , VR 24 (t = t 4), VR 25 (t = t 5), and VR 26 (t = t 6) in this order are sequentially displayed on the display device 50. For example, until time t = t3, the width in the direction of A1 of the rendered image displayed with the predetermined first luminance monotonously increases.

  On the other hand, from time t = t4 to time t = t6, the control circuit 22 gradually reduces the luminance of the rendering image displayed on the display device 50. For example, at time point t = t4 shown in FIG. 6, for example, the control circuit 22 sets the first region R1 corresponding to the frame data corresponding to the portion exceeding the second number set in advance when volume data is generated. The rendering image is displayed by assigning a predetermined second luminance lower than the luminance of. That is, in the generated volume data, the luminance to be allocated to a partial region corresponding to frame data that is temporally old, that is, the point recorded in the internal memory is relatively early is lowered. Then, the control circuit 22 gradually lowers the luminance of the rendering image allocated to the region R1 from time t = t4 to time t = t6, and at time t = t6, makes the luminance zero. Furthermore, the control circuit 22 gradually lowers the luminances to be assigned to the regions R2 and R3 in the order in which the corresponding frame data is recorded in the internal memory as in the region R1 also for the regions R2 and R3. As a result, it is possible to notify in advance the region that disappears in the rendered image to be displayed to the operator who visually recognizes the display device 50.

  In addition, the control circuit 22 may display additional information for describing the displayed rendered image together with the rendered image. The additional information is, for example, a time (period) in which received data by ultrasound is collected, and includes an elapsed time from a reference time. The reference time point is, for example, a time point at which collection of reception data by ultrasound is started. Further, the additional information includes a time window regarding display of the rendering image. The control circuit 22 measures and acquires an elapsed time from a reference time point using, for example, a system clock of an operating system (OS) installed in the ultrasonic diagnostic apparatus 1. The control circuit 22 may calculate and acquire the elapsed time from the reference time based on the number of frames recorded in the internal memory and the frame rate. The control circuit 22 displays the remaining time from the time when collection of reception data by ultrasonic waves is scheduled to end on the display device 50 instead of the elapsed time from the reference time or along with the elapsed time from the reference time. You may FIG. 7 is a diagram illustrating an example of a display mode of a rendering image displayed on the display device 50 according to the present embodiment. Arrow A1 shown in FIG. 7 represents the direction in which the ultrasonic probe 70 is swept. According to FIG. 7, the rendered image is synchronized with the ultrasonic probe 70 sweeping in the direction of A1, and the rendered images VR31 (t = t1), VR32 (t = t2), VR33 (t = t3) are obtained. , VR 34 (t = t 4), VR 35 (t = t 5), and VR 36 (t = t 6) in this order are sequentially displayed on the display device 50. Further, according to FIG. 7, the control circuit 22 displays additional information in addition to the rendered image.

  Specifically, in FIG. 7, the control circuit 22 displays that the time window relating to the display of the rendering image is "20 sec (seconds)". At this time, as shown in FIG. 7, the control circuit 22 is based on rendering image data such that the width in the direction of A1 of the rendering image displayed on the display device 50 is the width corresponding to the maximum "20 sec". Control the display of rendered images. The control circuit 22 displays, for example, a rendered image having a width in the direction A1 corresponding to “20 sec” at least from time t = t3 to time t = t5 on the display device 50. Further, as shown in FIG. 7, the control circuit 22 is a time during which reception data by ultrasonic waves are collected, and an elapsed time from the time when collection of reception data by ultrasonic waves is started is 2 sec ( The display is performed in the order of t = t1), 10 sec (t = t2), 20 sec (t = t3), 30 sec (t = t4), 40 sec (t = t5), and 50 sec (t = t6). As a result, the operator can grasp in more detail the collection status of reception data by ultrasonic waves, the width of the rendering image to be displayed in the direction of A1, and the like.

  According to the present embodiment, the control circuit 22 executes the system control function 227, and repeatedly generates B-mode image data based on the reception data collected by receiving the ultrasonic waves through the ultrasonic probe 70. . The control circuit 22 records the sequentially generated B-mode image data in the internal memory included in the image generation circuit 15, and the total amount of B-mode image data recorded in the internal memory or the oldest recorded in the internal memory Whenever the time during which the B mode image data is recorded in the internal memory satisfies a predetermined condition, the B mode image data recorded in the internal memory is deleted in order of age. The control circuit 22 generates volume data using B-mode image data corresponding to a plurality of time phases recorded in the internal memory every time B-mode image data of one frame is additionally recorded in the internal memory. . The control circuit 22 sequentially performs rendering processing on the generated volume data to generate rendering image data. The control circuit 22 executes the display control function 225 to sequentially display rendered images based on the generated rendered image data on the display device 50.

  As a result, the operator can visually recognize the rendered image during the sweep even if the sweep of the ultrasound probe is not completed, and if the rendered image as expected is not displayed, the ultrasound scan can be redone immediately can do.

  Therefore, it is possible to improve the efficiency of ultrasound image diagnosis using volume data.

[Other modifications]
In the above embodiment, the control circuit 22 displays the rendering image alone on the display device 50, but the present invention is not limited to this. That is, the control circuit 22 may additionally display an image based on image data related to the rendering image. FIG. 8 is a diagram illustrating an example of a display mode of a rendered image displayed on the display device 50 according to another embodiment. According to FIG. 8, in the display region R41, an ultrasound image displayed as a live image in real time during ultrasound scanning is displayed. In the display region R42, for example, an MPR image corresponding to the side B among the MPR images generated from volume data constituting the rendering image to be displayed is displayed. In the display region R43, for example, an MPR image corresponding to the C surface among the MPR images generated from volume data constituting the rendering image to be displayed is displayed. In the display area R44, a rendered image is displayed as a live image. The rendering image displayed in the display area R44 is gradually updated from the back side of the screen toward the front side. Thus, the operator can more reliably determine whether the rendering image as expected is displayed.

  Further, in the above embodiment, the control circuit 22 generates volume data using B-mode image data, but the invention is not limited to this. The control circuit 22 may generate volume data using, for example, B-mode image data and color Doppler image data. Color Doppler image data is image data in which colors are assigned to blood flow information collected using pulse waves in color Doppler mode. Also, the control circuit 22 may generate volume data using only color Doppler image data. Furthermore, the control circuit 22 is acquired by other imaging modes such as, for example, a tissue characterization imaging mode (elastic imaging mode, viscosity imaging mode, attenuation imaging mode), CHI (Contrast Harmonic Imaging) mode, and THI (Tissue Harmonic Imaging) mode. Volume data may be generated using various ultrasound image data.

  In the above embodiment, the control circuit 22 is a part of the generated volume data, and among the frame data used to generate the volume data, a part corresponding to the frame data corresponding to the old time phase. The luminance is lowered, and the rendering processing is performed on the volume data in which the part of the luminance is lowered. However, the timing to lower the brightness is not limited to this. For example, the control circuit 22 may lower the luminance of the image data corresponding to the old time phase among the image data corresponding to a plurality of time phases before generating the volume data. Further, the control circuit 22 lowers the luminance of a portion of the frame data used for generating the volume data, which corresponds to the frame data corresponding to the old time phase, which is a part of the generated rendering image. A portion of the rendered image with reduced luminance may be displayed.

  In the above embodiment, when the control circuit 22 can determine that the continuity of the cross section has been lost, for example, when the freeze instruction to instruct the freeze of the ultrasonic image is input through the input interface 20, the volume The generation of data may be stopped, and the rendered image displayed on the display device 50 may be reset. At this time, the control circuit 22 resumes generation of volume data using ultrasound image data generated after the point of time when the continuity is lost.

  Further, in the above embodiment, the control circuit 22 generates and displays volume data based on the preset second number, but the present invention is not limited to this. For example, the control circuit 22 may receive a change instruction to change the second number via a rotary switch or the like included in the input interface 20. That is, the control circuit 22 receives a change instruction to change the total amount of ultrasound image data used to generate volume data. The control circuit 22 may receive a change instruction to change the time window related to the display of the rendering image.

  Further, in the above-described embodiment, the control circuit 22 generates volume data by using ultrasound image data after RAW-pixel conversion such as B-mode image data or Doppler image data, but is not limited to this. The control circuit 22 may generate volume data using, for example, two-dimensional RAW data before RAW-pixel conversion such as B-mode RAW data or Doppler RAW data. At this time, the control circuit 22 manages one two-dimensional RAW data recorded in the RAW data memory as one frame on a frame basis. The control circuit 22 deletes data in order from the oldest one when the two-dimensional RAW data recorded in the RAW data memory satisfies a predetermined condition. Further, the control circuit 22 generates volume data by performing RAW-voxel conversion including interpolation processing in which spatial position information is added to two-dimensional RAW data recorded in the RAW data memory. .

  Further, in the above embodiment, the control circuit 22 associates the positional information of the ultrasonic probe 70 acquired by the position sensor system 30 with the ultrasonic image data generated on a frame basis to associate the positional information. Although volume data is generated using the ultrasound image data, the present invention is not limited to this. The control circuit 22 grasps in advance, for example, an operation of the ultrasonic probe 70, for example, an initial position, a sweep (moving) direction, and a moving speed via the input interface 20. The control circuit 22 calculates positional information of each of the ultrasonic image data generated in frame units based on the initial position, the sweep direction, and the moving speed of the ultrasonic probe 70 that has been grasped. The control circuit 22 associates the calculated position information with the corresponding ultrasound image data. The control circuit 22 generates volume data using ultrasound image data corresponding to the second number of time phases associated with the position information. This makes it possible to generate volume data in real time during an ultrasonic scan, without acquiring position information of the ultrasonic probe 70 from the position sensor system 30.

  In the above embodiment, volume data is generated using ultrasound image data in frame units, but the present invention is not limited to this. For example, the control circuit 22 executes the system control function 227 and generates three-dimensional ultrasound image data (volume data) to which time information indicating time of generation is added in volume units. The control circuit 22 executes the recording control function 221, and records the generated volume data in an internal memory provided in the image generation circuit 15. The control circuit 22 manages the volume data recorded in the internal memory based on the number of volumes recorded in the internal memory, the elapsed time since it is recorded in the internal memory, and the like. On the other hand, the control circuit 22 executes the image processing function 223, and executes interpolation processing or the like with time information added to a plurality of volume data recorded in the internal memory to obtain four-dimensional ultrasonic image data. Generate Four-dimensional ultrasound image data is, for example, image data in which images based on three-dimensional ultrasound image data are arranged in time series, and is image data that can be referred to as a moving image. At this time, as the ultrasonic probe 70, a 2D array probe capable of three-dimensional scanning, a mechanical 4D probe or the like is used.

  Further, in the above embodiment, each function of the control circuit 22 has been described on the premise of the ultrasonic diagnostic apparatus, but the present invention is not limited to this. For example, each function of the control circuit 22 may be implemented in the optical ultrasonic diagnostic apparatus. The optical ultrasonic diagnostic apparatus externally applies pulsed infrared light to a predetermined part of the body of the subject, urges the transmission of ultrasonic waves in the part, and the transmission is performed via the ultrasonic probe. It is an apparatus which collects reception data by receiving an ultrasonic wave, and produces | generates optical ultrasound image data based on the said reception data.

  Further, in the above embodiment, the control circuit 22 is applied in the process of generating volume data as compared to the case where the reception data by the ultrasonic wave is not collected while the reception data by the ultrasonic wave is collected. Part of the image processing may be omitted. For example, while the ultrasonic scan is being performed in accordance with the sweep of the ultrasonic probe 70, the control circuit 22 performs a part of the image processing necessary for volume data generation, for example, interpolation processing in step SB2 shown in FIG. Omit a part of etc. As a result, the processing load of volume data generation can be reduced, and volume data can be generated in real time during an ultrasound scan. Note that, for example, after the completion of the ultrasound scan, the control circuit 22 generates the volume data for all the frame data corresponding to the second number of time phases recorded in the internal memory of the image generation circuit 15. Image processing may be performed to generate volume data. At this time, the control circuit 22 can redisplay a high quality rendered image by the generated volume data.

  The word “processor” used in the above description may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), or an application specific integrated circuit (ASIC)), a programmable logic device (for example, It means circuits such as Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA). The processor realizes the function by reading and executing the program stored in the recording circuit. Each processor according to the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize the function. Good. Furthermore, a plurality of components in FIG. 1 may be integrated into one processor to realize its function.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

  DESCRIPTION OF SYMBOLS 1 ... ultrasound diagnostic apparatus, 10 ... apparatus main body, 11 ... ultrasound transmission circuit, 12 ... ultrasound reception circuit, 13 ... mode processing circuit, 14 ... Doppler processing circuit, 15 ... image generation circuit, 17 ... internal recording circuit, 18 image memory 19 image database 20 input interface 21 communication interface 22 control circuit 30 position sensor system 40 external device 50 display device 60 input device 70 ultrasonic wave Probe, 221: recording control function, 223: image processing function, 225: display control function, 227: system control function.

Claims (12)

An image data generation unit that repeatedly generates image data based on reception data collected by receiving an ultrasonic wave via an ultrasonic probe;
The image data is recorded in a memory, and a total amount of the image data recorded in the memory or a time when the oldest image data recorded in the memory is recorded in the memory satisfies a predetermined condition A recording control unit for deleting the image data recorded in the memory in the order of oldness each time;
A volume for generating volume data using the image data corresponding to a plurality of time phases recorded in the memory each time the image data generation unit generates the image data corresponding to at least one time phase. A data generation unit,
A rendering processing unit that generates a rendering image by sequentially performing rendering processing on the generated volume data;
A display control unit that causes the display unit to sequentially display the generated rendering image;
Ultrasound diagnostic device.   When the total amount of the image data recorded in the memory reaches a predetermined upper limit, or when the time during which the oldest image data is recorded in the memory reaches a predetermined upper limit, the recording control unit The ultrasonic diagnostic apparatus according to claim 1, wherein the image data recorded in the memory are deleted in order from the oldest one.   The ultrasonic diagnostic apparatus according to claim 1, wherein the image data is associated with position information on the ultrasonic probe.   The ultrasonic diagnostic apparatus according to any one of claims 1 to 3, wherein the volume data generation unit lowers the luminance of image data corresponding to an old time phase among image data corresponding to the plurality of time phases.   The rendering processing unit reduces the luminance of a portion of the image data that is a part of the volume data and that is used to generate the volume data and that corresponds to the image data that corresponds to the old time phase, The ultrasonic diagnostic apparatus according to any one of claims 1 to 3, wherein the rendering process is performed on the volume data in which the luminance of the unit has been lowered.   The rendering processing unit is configured to reduce the luminance of a part of the generated rendering image that corresponds to image data corresponding to an old time phase among the image data used to generate the volume data. The ultrasound diagnostic apparatus according to any one of Items 1 to 3.   The volume data generation unit generates the volume data using image data generated after a point of time when the continuity regarding generation of the image data is lost. The ultrasound diagnostic device according to any one of the above.   The ultrasonic diagnostic apparatus according to any one of claims 1 to 7, wherein the display control unit causes the display unit to display additional information including an elapsed time from a reference time point and a time window related to the display of the rendering image. .   The ultrasonic diagnostic apparatus according to any one of claims 1 to 8, further comprising a reception unit that receives a change instruction to change the total amount of the image data used to generate the volume data.   The volume data generation unit omits a part of the image processing performed in the process of generating the volume data, while collecting the reception data, as compared to the case where the reception data is not collected. The ultrasonic diagnostic apparatus according to any one of claims 1 to 7.   The volume data generation unit generates volume data each time image data corresponding to at least two phases is generated so that the latest image data is included in the image data corresponding to the plurality of time phases. The ultrasonic diagnostic apparatus according to any one of Items 1 to 8. On the computer
An image data generation function of repeatedly generating image data based on reception data collected by receiving an ultrasonic wave via an ultrasonic probe;
The image data is recorded in a memory, and a total amount of the image data recorded in the memory or a time when the oldest image data recorded in the memory is recorded in the memory satisfies a predetermined condition A recording control function of deleting the image data recorded in the memory in the order of oldness each time;
A volume data generation function of generating volume data using the image data corresponding to a plurality of time phases recorded in the memory each time the image data corresponding to at least one time phase is generated;
A rendering processing function of generating a rendering image by sequentially performing rendering processing on the generated volume data;
A control program for realizing a display control function of causing the display unit to sequentially display the generated rendering image.