Ultrasonic diagnostic apparatus and image selection method

Abstract

To increase possibility that a proper image is displayed after freeze operation.SOLUTION: When freeze operation is performed at a time t2, an evaluation period 60 is set to an image column 54 within a cine memory based on first reference information 58. An image group 62 belonging to the evaluation period 60 is individually evaluated, and thereby a recommendation image 68 is selected from in the image group 62. The recommendation image 68 is displayed after the freeze operation.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an ultrasound diagnostic apparatus and an image selection method, and in particular to a technique for selecting an image to be displayed after a freeze operation. [Background technology]

[0002] An ultrasound diagnostic device is used in an ultrasound examination of a subject, and is operated by a user, that is, an examiner (such as a doctor or a medical technician).

[0003] When the ultrasound diagnostic device is performing a transmission / reception operation, i.e., a real-time operation, a moving image is displayed on the display of the ultrasound diagnostic device. If an image of interest, such as a lesion, appears during observation of the moving image, the examiner performs a freeze operation. The freeze operation stops transmission and reception, and at the same time, the display switches from moving image display to still image display. In other words, the ultrasound diagnostic device transitions from a real-time operating state to a frozen state. After this transition, the most recent image acquired last is displayed as a still image. The examiner then searches for the desired image by performing image rewinding and image forwarding operations. When the desired image is identified, the image is stored and incorporated into the examination report.

[0004] It is also possible to control the display so that, instead of the latest image, a previous image acquired a predetermined period prior to the acquisition of the latest image or a previous image acquired at the time of the freeze operation is displayed at the time of transition to the freeze state. However, such uniform processing reduces the possibility that the displayed image is the image desired by the examiner.

[0005] In the ultrasound diagnostic device disclosed in Patent Document 1, a predetermined time range is determined based on the time of a freeze operation, and a diagnostic image is selected from a plurality of images that belong to the predetermined time range. The predetermined time range is designated in advance by a user. Patent Document 1 does not disclose a technology for adaptively setting the predetermined time range.

[0006] The ultrasound diagnostic device disclosed in Patent Document 2 is provided with a voice input function. The pronunciation of "freeze" is recognized, and a freezing operation is performed based on the recognition. In this ultrasound diagnostic device, an image to be displayed after transition to the freeze state is selected based on the start of voice input. Patent Document 2 does not disclose a technology for adaptively selecting an image to be displayed after transition to the freeze state. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2012-161503 A [Patent Document 2] JP 2009-61040 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present disclosure is to increase the likelihood that a suitable image will be displayed after a freeze operation, or to appropriately determine a search range for an image to be displayed after a freeze operation. [Means for solving the problem]

[0009] The ultrasound diagnostic device of the present disclosure is characterized in that it includes a memory unit that stores an image sequence consisting of a plurality of images arranged in chronological order generated by repeated transmission and reception of ultrasound; a setting unit that, when a freeze operation is performed, adaptively sets an evaluation period for the image sequence based on reference information indicating the status of the ultrasound examination; a selection unit that extracts an image group belonging to the evaluation period from the image sequence and selects a recommended image from the image group by evaluating each image constituting the image group; and a display unit that displays the recommended image after the freeze operation.

[0010] The image selection method of the present disclosure includes the steps of: storing in a memory unit an image sequence consisting of a plurality of images arranged in chronological order, which are generated by repeated transmission and reception of ultrasound; adaptively setting an evaluation period for the image sequence based on reference information indicating the status of the ultrasound examination when a freeze operation is performed; and extracting an image group belonging to the evaluation period from the image sequence and evaluating each image constituting the image group, thereby selecting a recommended image from the image group, wherein the recommended image is displayed as a still image after the freeze operation after a moving image based on the image sequence is displayed. Effect of the Invention

[0011] According to the present invention, it is possible to increase the possibility that a suitable image will be displayed after a freeze operation, or to appropriately determine a search range for an image to be displayed after a freeze operation. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing an ultrasound diagnostic apparatus according to an embodiment. [Diagram 2] FIG. 13 is a diagram showing freeze control (image selection method). [Diagram 3] FIG. 2 illustrates an example of the configuration of a freeze control unit; [Figure 4] FIG. 2 illustrates a first exemplary configuration of a setting unit. [Diagram 5] FIG. 11 illustrates a second exemplary configuration of the setting unit. [Figure 6] FIG. 2 illustrates a first exemplary configuration of a selection unit. [Figure 7] FIG. 13 is a diagram illustrating a second configuration example of the selection unit. [Figure 8] FIG. 13 is a diagram showing a display example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment will be described with reference to the drawings.

[0014] (1) Overview of the embodiment An ultrasound diagnostic device according to an embodiment has a storage unit, a setting unit, a selection unit, and a display unit. The storage unit stores an image sequence consisting of a plurality of images arranged in chronological order, which are generated by repeated transmission and reception of ultrasound. When a freeze operation is performed, the setting unit sets an evaluation period for the image sequence based on reference information indicating the status of the ultrasound examination. The selection unit extracts an image group belonging to the evaluation period from the image sequence, and selects a recommended image from the image group by evaluating each image constituting the image group. The display unit displays the recommended image after the freeze operation.

[0015] According to the above configuration, since the evaluation period is set according to the situation of the ultrasound examination, and the recommended image is selected by individual evaluation of the image group belonging to the evaluation period, the possibility that the recommended image displayed after the freeze operation is the image desired by the examiner is increased. Since a series of processes after the freeze operation are automatically executed, no burden is placed on the examiner. After the recommended image is displayed, the displayed image can be manually switched as necessary. In this case, the possibility that the desired image can be reached in a short time is increased.

[0016] The above reference information is information that is referenced for setting an evaluation period, and is information that reflects the current status of the ultrasound examination. In an embodiment, the above reference information includes at least one of information that identifies the type of image group (information that identifies the ultrasound examination method), information that identifies the examiner, and information that identifies the type of freeze operation. This reference information for setting the evaluation period is first reference information. Second reference information, which will be described later, is information that is the same as the first reference information, or information that is different from the first reference information. In an embodiment, the first reference information includes the second reference information.

[0017] In an embodiment, the setting unit includes a first determination unit and a second determination unit. The first determination unit determines a past reference time that is used as a reference when setting the evaluation period based on all or part of the reference information. The second determination unit determines a time span that is the size of the evaluation period based on all or part of the reference information.

[0018] For example, one or both of the past reference time and the time span may be changed depending on the type of image group, the examiner, or the type of freeze operation. If one or both of the past reference time and the time span are changed based on multiple pieces of information, the evaluation period can be set more appropriately. The past reference time may be determined based on the time when a freeze command was generated or recognized, the time when a specific process was started or ended in accordance with the freeze command, etc.

[0019] In an embodiment, the selection unit evaluates each image constituting the image group based on the second reference information indicating the status of the ultrasound examination. For example, the evaluation method or evaluation conditions may be changed depending on the type of the image group or the examiner. If the image group is evaluated based on multiple pieces of information, a more appropriate evaluation result can be obtained.

[0020] The ultrasound diagnostic apparatus according to the embodiment further includes a generating unit. The generating unit generates a guide image including a first display element indicating an evaluation period and a second display element indicating a time corresponding to the recommended image. The recommended image and the guide image are displayed on the display unit. With this configuration, it is possible to provide the examiner with information indicating the acquisition timing of the displayed recommended image, and also to provide the examiner with information indicating the evaluation period during which the search for the recommended image was performed. Through observation of the recommended image and the guide image, the examiner can determine the necessity of a manual search, and can also determine the direction and range of the manual search when a manual search is performed.

[0021] The image selection method according to the embodiment includes a storage step, a setting step, and a selection step. In the storage step, an image sequence consisting of a plurality of images arranged in chronological order, generated by repeated transmission and reception of ultrasound, is stored in a storage unit. In the setting step, when a freeze operation is performed, an evaluation period is set for the image sequence based on reference information indicating the status of the ultrasound examination. In the selection step, a group of images belonging to the evaluation period is extracted from the image sequence, and each image constituting the image group is evaluated. This allows a recommended image to be selected from the image group. After a moving image based on the image sequence is displayed, the recommended image is displayed as a still image after the freeze operation.

[0022] The image selection method can be realized by a hardware function or a software function. In the latter case, a program for executing the image selection method is installed in an ultrasound diagnostic device via a network or a portable storage medium. The ultrasound diagnostic device has a non-transitory storage medium in which the program is stored.

[0023] (2) Details of the embodiment An ultrasonic diagnostic apparatus according to an embodiment is shown in Fig. 1. This ultrasonic diagnostic apparatus is a medical device used for ultrasonic examination of a subject.

[0024] The ultrasonic probe 10 is an instrument for transmitting and receiving ultrasonic waves. Specifically, the ultrasonic probe 10 is composed of a probe head, a cable, and a connector. The examiner holds the probe head, and the transmitting and receiving surface of the probe head is brought into contact with the surface of the subject. A transducer element array consisting of a plurality of transducer elements is provided within the probe head. Ultrasound is emitted from the transducer element array into the living body, and the reflected waves from within the living body are detected by the transducer element array.

[0025] 1 shows an ultrasonic beam 12 formed by a transducer array. A beam scan plane 14 is formed by electronically scanning the ultrasonic beam 12. The ultrasonic beam 12 corresponds to a transmission beam and a reception beam. Known electronic scanning methods include an electronic linear scanning method and an electronic sector scanning method. A two-dimensional transducer array may be provided in a probe head to acquire volume data from within a living body.

[0026] The probe head is provided with a switch 16 as necessary. The switch 16 is a freeze switch. When the switch 16 is operated, a freeze signal is output to the information processing unit 30. A probe that does not include the switch 16 may be used.

[0027] The transmitter 18 is an electronic circuit that functions as a transmission beamformer, and during transmission, supplies a plurality of transmission signals in parallel to the transducer element array, thereby forming a transmission beam.

[0028] The receiver 20 is an electronic circuit that functions as a receive beamformer, and during reception, it applies phasing addition to multiple receive signals output in parallel from the transducer array, thereby generating beam data. Multiple beam data aligned in the electronic scanning direction are generated as the ultrasonic beam is electronically scanned. Frame data is composed of these beam data. A beam data processing unit is provided between the receiver 20 and the image forming unit 22, but is not shown in the figure.

[0029] The image forming unit 22 forms an ultrasound image sequence (hereinafter, simply referred to as an image sequence) based on the input frame data sequence. The image forming unit 22 has a digital scan converter (DSC) as an electronic circuit. The DSC has a coordinate conversion function, a pixel interpolation function, and the like. The image sequence is composed of a plurality of images arranged on a time axis. Each image is, for example, a tomographic image (B-mode tomographic image). Various types of images are generated according to the ultrasound examination method (including the operation mode). In addition to tomographic images, these include color flow mapping images (CFM images), images including puncture images (puncture images), images including contrast agent images (contrast images), and the like.

[0030] The image sequence generated in the image forming unit 22 is sent to the display processing unit 26 and also sent to the cine memory 24. In a transmission / reception operating state, i.e., a real-time operating state, the image sequence is displayed as a moving image on the display 28. In a freeze state, a still image read out from the cine memory 24 is displayed on the display 28. In the embodiment, after a freeze operation, an automatically selected recommended image is displayed first. This will be described in detail later. The display 28 is composed of an organic EL display device, an LCD, or the like.

[0031] The cine memory 24 is a storage unit that stores a sequence of images, and each image is temporarily stored in the cine memory 24. The cine memory 24 is composed of a semiconductor memory, a hard disk, etc. The cine memory 24 has a ring buffer structure. A plurality of images output from the image forming unit 22 are stored in the cine memory 24 in chronological order. During the storage process, a process of overwriting and erasing the oldest image in the cine memory 24 is repeated in sequence.

[0032] A cine memory may be provided between the receiving unit 20 and the image forming unit 22. When such a modified example is adopted, a frame data sequence is stored in the cine memory. The frame data sequence is actually an image sequence. Even in the modified example, it can be said that the image sequence is stored in the cine memory.

[0033] The information processing unit 30 functions as a control unit and a calculation unit. In the embodiment, the information processing unit 30 is configured by a CPU that executes a program. The information processing unit 30 controls the operation of each component shown in FIG. 1. In FIG. 1, some of the many functions performed by the information processing unit 30 are represented by a plurality of blocks. The information processing unit 30 functions as a voice recognition unit 32, an image analysis unit 34, and a freeze control unit 36.

[0034] An operation panel 38 is connected to the information processing unit 30. The operation panel 38 is an input device having a plurality of buttons, a plurality of knobs, a trackball, etc. A freeze button 40 included in the operation panel 38 is shown in Fig. 1. When the freeze button 40 is operated, a freeze signal is output from there to the information processing unit 30.

[0035] The microphone 42 is provided as necessary. Specifically, the microphone 42 is provided when the operation of the ultrasound diagnostic device is controlled by voice input. The voice recognition unit 32 applies voice recognition to the voice signal output from the microphone 42, and generates a command signal based on the voice recognition result. The information processing unit 30 executes control or processing according to the command signal. In the embodiment, when the voice "freeze" is input to the microphone, the voice recognition unit 32 recognizes "freeze" and generates a freeze signal as a command signal.

[0036] The image analysis unit 34 functions when the operation of the ultrasound diagnostic device is controlled by the movement of the probe head. That is, the image analysis unit 34 functions when a gesture is input. In detail, the image analysis unit 34 analyzes the input image sequence and analyzes the type of probe head movement. In the embodiment, a separation movement in which the transmitting / receiving surface of the probe head is separated from the body surface of the subject is associated with a freeze operation. The image analysis unit 34 determines the occurrence of a separation movement based on the image sequence, and generates a freeze signal accordingly. The image analysis unit 34 is provided as necessary.

[0037] An electrocardiograph 44 is connected to the information processing unit 30. The electrocardiograph 44 generates an ECG signal. An electrocardiogram waveform is displayed on the screen of the display 28 based on the ECG signal. A foot pedal for a freeze operation may be connected to the information processing unit 30.

[0038] When a freeze signal is generated, the freeze control unit 36 ​​executes freeze control to transition the ultrasound diagnostic apparatus from a real-time operating state to a freeze state. Specifically, when a freeze signal is generated, the freeze control unit 36 ​​stops transmission and reception, and at the same time switches from moving image display to still image display. In the embodiment, the still image that is first displayed after transition to the freeze state is a recommended image that is automatically selected. This will be described in detail below.

[0039] Fig. 2 shows a schematic diagram of the freeze control (image selection method) executed by the freeze control unit. Some items are exaggerated in Fig. 2. (A) shows a number of events on the time axis. (B) shows the state of the cine memory.

[0040] In a moving image observation state, for example, when an examiner recognizes a lesion at time t1, the examiner performs a freeze operation at time t2. The period from time t1 to time t2 (response period) changes depending on the freeze operation method.

[0041] For example, if a method using a freeze button on the operation panel is selected, the response period will generally be short. If a method using voice input or a method using probe operation is selected, the response period will generally be long. In the case of a method using voice input, the response time depends heavily on the speaking speed. If a method using a switch on the probe is selected, the response period will vary depending on the examination area and the installation state of the switch. The response period will also vary depending on the examiner himself. For example, an examiner with high ultrasound examination skills will generally have a short response time. An examiner with little experience in ultrasound examinations will generally have a long response time. The response period will also vary depending on the image type and examination area.

[0042] When a freeze operation is recognized, a transition from the real-time state to the frozen state occurs as described above. It takes some time for the transition to complete. Time t3 indicates when the frozen state is completed. The recommended image is displayed at time t4. Time t4 may coincide with time t3. In the illustrated example, the state before time t3 is the transmitting / receiving state (real-time operating state). The state after time t3 is the frozen state.

[0043] When a freeze operation is performed at time t2, the freeze control section sets an evaluation period (evaluation interval) 60 for the image sequence 54 stored in the cine memory based on the first reference information 58 (see reference numeral 56).

[0044] Specifically, the freeze control unit determines a past reference time ts based on the first reference information 58, and determines a time span Δt based on the first reference information 58. In the embodiment, the center of the evaluation period is determined by the past reference time ts, and the time span Δt determines the time length of the evaluation period.

[0045] Each image is provided with information (time stamp) indicating the time when it was acquired (or generated). This information may be used to identify the image group. A past reference time ts may be determined using the time when a freeze command is generated, the time when a freeze command is recognized, a predetermined time in the freeze control process, etc. as a reference time for calculation. Time lengths ta, tb that define the start and end of evaluation period 60 may be determined using time t3 as a reference for calculation.

[0046] The first reference information is information that is referred to when setting an evaluation period. For example, the first reference information may include information that identifies an examiner, information that identifies a type of image sequence (which may also be called information that identifies an examination method or information that identifies an examination site), information that identifies a freeze operation method, etc. Specific examples of the first reference information will be described later.

[0047] The freeze control unit identifies an image group 62 belonging to the evaluation period 60 in the image sequence stored in the cine memory, and reads out the image group 62 from the cine memory. The freeze control unit then individually evaluates the images constituting the image group 62 based on the second reference information, and assigns a rank (which may also be referred to as a score or an evaluation value) to each image (see reference numeral 64). The freeze control unit identifies the highest rank from the assigned ranks, and selects the image 68a assigned the highest rank as the recommended image 68 (see reference numeral 64).

[0048] The second reference information is information that is referenced when evaluating each image that constitutes an image group belonging to an evaluation period. For example, the second reference information may include information that identifies the examiner, information that identifies the type of image sequence, etc. All or a part of the first reference information may be used as the second reference information. Specific examples of the second reference information will be described later. Note that various known methods may be used as the image evaluation method. The image evaluation method or image evaluation conditions may be switched depending on the type of image sequence. The image evaluation model may be switched depending on the type of image sequence.

[0049] The freeze control unit displays the recommended image selected as above on the display. The display timing is time t4, but it is desirable to execute freeze control so that time t4 is as close as possible to time t3, ideally so that time t4 coincides with time t3. The recommended image is a still image that is displayed first after the freeze operation. Thereafter, the displayed image is switched as necessary. In that case, an image forwarding operation or an image back operation is performed starting from image 68a. An image search beyond the image group 62 may be performed.

[0050] According to the above freeze control, the evaluation period is set according to the state of the ultrasound examination, and the image group can be individually evaluated taking into account the state of the ultrasound examination, so that the possibility that the image desired by the examiner will be displayed as the recommended image after the freeze operation is increased. The examiner is not burdened when the recommended image is displayed. Even if the recommended image is not the image desired by the examiner, the possibility that the image search can be performed in a short time is increased.

[0051] The examiner may select whether or not to execute the freeze control. When the examiner selects not to execute the freeze control, conventional freeze control is executed. In that case, the latest image acquired last after the transition to the freeze state is displayed as a still image. The freeze control method may be switched by switching the operation mode of an input device for inputting a freeze. For example, when a freeze button provided on an operation panel is pressed for a normal time (short time), conventional freeze control may be executed, and when the pressed time is long, the freeze control described above may be executed. A switch, button, or the like may be provided for switching the freeze control method.

[0052] 3 shows an example of the configuration of the freeze control unit 36. The freeze control unit 36 ​​is made up of a setting unit 70 and a selection unit 72. The setting unit 70 has a reference time determiner 74 functioning as a first determination unit and a time width determiner 76 functioning as a second determination unit. The reference time determiner 74 determines a past reference time ts based on all or a part of the first reference information 58. The time width determiner 76 determines a time width Δt based on all or a part of the first reference information 58. The evaluation period 60 is determined by the past reference time ts and the time width Δt.

[0053] 3 shows a specific example of the first reference information 58. The first reference information 58 includes information for identifying an image type (type of image sequence), information for identifying an examiner, information for identifying a freeze operation method, etc. The first reference information 58 may also include information for identifying a frame rate, information for identifying a cardiac cycle, information for identifying a time required for a freeze operation (or freeze input), etc.

[0054] The evaluation period 60 set by the setting unit 70 is notified to the selection unit 72. The selection unit 72 reads out the image group 62 from the frame memory. The selection unit 72 has an evaluator 78 that individually evaluates the image group 62. The evaluator 78 evaluates each image based on the second reference information 66. The second reference information 66 includes, for example, information identifying the image type and information identifying the examiner. The second reference information 66 may also include other information. The evaluator 78 assigns a rank to each image. The selection unit 72 selects the image with the highest rank as the recommended image 68.

[0055] 4 shows a first configuration example of the setting unit 70. The setting unit 70 includes a look-up table (LUT) 82. The LUT 82 functions as the reference time decider and the time width decider described above. An LUT for the reference time decider and an LUT for the time width decider may be provided.

[0056] In the LUT 82, a past reference time (ts) 90 and a time span (Δt) 92 corresponding to each combination of the examiner 84, the image type 86, the freeze operation method, etc. are registered. That is, when a combination specified by the first reference information 58 is input to the LUT 82, the past reference time 90 and the time span 92 corresponding to that combination are output from the LUT.

[0057] 5 shows a second configuration example of the setting unit 70. The setting unit 70 has a decision model 94 that functions as a reference time decider and a time width decider. The decision model 94 is generated by machine learning. For example, the decision model 94 is configured by a network such as CNN. When information for identifying an examiner, information for identifying an image type, information for identifying a freeze operation method, etc. is given to the decision model 94 as the first reference information 58, information for identifying a past reference time ts and a time width Δt that match the first reference information 58 is output from the decision model 94. A decision model for determining a past reference time and a decision model for determining a time width may be provided.

[0058] FIG. 6 shows a first configuration example of the selection unit 72. The selection unit 72 has an evaluator 78 and a selector 100. The second reference information 66 and the image group 62 are input to the evaluator 78. The evaluator 78 has a plurality of evaluation models 96-1 to 96-m. Each of the evaluation models 96-1 to 96-m is an image evaluation model generated by machine learning. An evaluation model to be actually used is selected based on the second reference information 66. The image group 62 is provided to the evaluation model. The evaluation model evaluates the superiority or inferiority of each image and outputs a rank 98 for each image. The evaluator 78 is configured by a network such as CNN.

[0059] For example, the multiple evaluation models 96-1 to 96-m correspond to multiple image types, or the multiple evaluation models 96-1 to 96-m correspond to multiple combinations (combinations of image types and examiners).

[0060] The selector 100 receives a plurality of ranks 98 generated by evaluating a plurality of images. The selector 100 identifies a highest rank among the plurality of ranks 98 and selects, from the set of images 62, the image corresponding to the highest rank as a recommended image.

[0061] For example, when evaluating a tomographic image, the clarity of a tissue image may be evaluated. When evaluating a blood flow image (including a CFM image), the clarity and size of the blood flow image may be evaluated. When evaluating a puncture image, the clarity of a puncture needle image may be evaluated. When evaluating a contrast image, the clarity and size of a contrast agent image may be evaluated.

[0062] Fig. 7 shows a second configuration example of the selection unit 72. In Fig. 7, components similar to those shown in Fig. 6 are given the same reference symbols, and their description will be omitted. The evaluator 78 has a single evaluation model 104. The evaluation model 104 evaluates each image constituting the image group 62 while taking into account the second reference information 66. The evaluation model 104 is also generated by machine learning. The evaluation model 104 is composed of a network such as CNN.

[0063] 8 shows an example of an image displayed when the freeze state is established. A recommended image 108 is displayed on a screen 106 of the display device. In the illustrated example, the recommended image 108 is a tomographic image. Depending on the ultrasound examination method, a CFM image, a puncture image, a contrast image, or the like is displayed.

[0064] An electrocardiogram waveform 130 is displayed below the recommended image 108. The electrocardiogram waveform 130 includes a graphic 132 indicating a time axis and a number of R waves. A guide image 110 is displayed below the electrocardiogram waveform 130. The guide image 110 includes a graphic 112 indicating a time axis, a graphic 114 indicating an evaluation period, and a graphic 116 indicating the time when the recommended image was acquired. The right end 120 of the time axis corresponds to the time when the frozen state is established. The time axis scale of the electrocardiogram waveform 130 and the time axis scale of the guide image 110 are the same. Each graphic is a display element.

[0065] The start and end of the evaluation period can be easily recognized by observing the figure 114. The acquisition time of the recommended image can be easily recognized by observing the figure 116. The figure 114 has a band-like shape, but other shapes may be used instead of the band-like shape. The figure 116 has a triangle, but other shapes may be used instead of the triangle.

[0066] The indicator 122 is composed of a numerator 126 and a denominator 128. The denominator 128 represents the total number of images constituting the image sequence stored in the cine memory. The numerator 126 indicates the number of the recommended image 108 in the total number of images.

[0067] After the recommended image 108 is displayed, when an image forward operation or a previous image operation is performed, the figure 116 slides to the right or left (see reference numeral 118). Accordingly, the images displayed on the screen 106 are switched in sequence. The content of the indicator 122 also changes. The guide image 110 enables the examiner to intuitively recognize the time when the recommended image was acquired, the size and position of the evaluation period, and the like.

[0068] A plurality of recommended images may be displayed after the freeze operation. In this case, a plurality of recommended images consecutive in time may be displayed, or a plurality of recommended images discretely specified on the time axis may be displayed. A graph showing the change over time of the rank sequence assigned to the image sequence may be displayed in the figure (box) 144. By adopting such a configuration, it becomes easier to search for images. Such a graph may be displayed outside the figure 144. [Explanation of symbols]

[0069] 10 ultrasound probe, 16 freeze switch, 24 cine memory, 32 voice recognition unit, 34 image analysis unit, 36 freeze control unit, 40 freeze button.

Claims

1. a storage unit that stores an image sequence consisting of a plurality of images arranged in chronological order, the images being generated by repeatedly transmitting and receiving ultrasonic waves; a setting unit that sets an evaluation period for the image sequence based on reference information indicating a state of the ultrasound examination when a freeze operation is performed; a selection unit that extracts a group of images belonging to the evaluation period from the sequence of images and selects recommended images from the group of images by evaluating each image constituting the group of images; a display unit that displays the recommended image after the freeze operation; 1. An ultrasonic diagnostic apparatus comprising:

2. 2. The ultrasonic diagnostic apparatus according to claim 1, The setting unit is a first determination unit that determines a past reference time that serves as a reference when setting the evaluation period based on all or a part of the reference information; A second determination unit that determines a time span that is a size of the evaluation period based on all or a part of the reference information; 1. An ultrasonic diagnostic apparatus comprising:

3. 2. The ultrasonic diagnostic apparatus according to claim 1, the reference information includes at least one of information for identifying a type of the image sequence, information for identifying an examiner, and information for identifying a type of the freeze operation; 1. An ultrasonic diagnostic apparatus comprising:

4. 2. The ultrasonic diagnostic apparatus according to claim 1, the reference information is first reference information, the selection unit evaluates each image constituting the image group based on second reference information indicating a status of the ultrasonic examination; 1. An ultrasonic diagnostic apparatus comprising:

5. 5. The ultrasonic diagnostic apparatus according to claim 4, the second reference information includes at least one of information identifying a type of the image sequence and information identifying an examiner; 1. An ultrasonic diagnostic apparatus comprising:

6. 2. The ultrasonic diagnostic apparatus according to claim 1, a generating unit that generates a guidance image including a first display element indicating the evaluation period and a second display element indicating a time corresponding to the recommendation image, The recommendation image and the guide image are displayed on the display unit.

1. An ultrasonic diagnostic apparatus comprising:

7. storing an image sequence, which is made up of a plurality of images arranged in chronological order and generated by repeatedly transmitting and receiving ultrasonic waves, in a storage unit; setting an evaluation period for the image sequence based on reference information indicating a state of the ultrasound examination when a freeze operation is performed; a step of extracting a group of images belonging to the evaluation period from the sequence of images, and evaluating each image constituting the group of images to select recommended images from the group of images; Including, After the video based on the image sequence is displayed, the recommended image is displayed as a still image after a freeze operation.

13. An image selection method comprising:

Images