JP2016097255A - Ultrasonic image processor and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a partial dynamic image being a diagnosis object candidate to be selected for each view from a dynamic image whose view is switched midway without an extra burden on an inspector.SOLUTION: A frame array processing part 32 divides a frame array into a partial frame array for each heartbeat on the basis of heartbeat data. The frame array processing part 32 also selects the frame acquired at the R wave time phase in each partial frame array as a representative frame. A determination value calculation part 36 calculates a plurality of distances corresponding to a plurality of views as a determination value set for each representative frame. The determination value set is information on the view (implementation view) at the time of acquiring the representative frame. The partial frame array (dynamic image) of a diagnosis object candidate is extracted for each view on the basis of the plurality of determination value sets (matrix 62) calculated for the plurality of representative frames.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ultrasonic image processing apparatus and program, and more particularly, to processing of a frame sequence acquired by transmission / reception of ultrasonic waves.

  An ultrasonic diagnostic apparatus is an apparatus that transmits and receives ultrasonic waves to and from a subject and forms an ultrasonic image based on data obtained thereby. Specifically, for example, in the well-known B mode, an ultrasonic beam is repeatedly electronically scanned to obtain a reception frame sequence (reception frame data sequence) in time series order, and a display frame is obtained by processing such as coordinate conversion. A column (display frame data column) is generated. The display frame sequence forms a B-mode moving image, which is displayed on the screen in real time. Since the received frame sequence forms the basis of the display frame sequence, it can also be considered as a moving image.

  The reception frame sequence or the display frame sequence is stored in a cine memory, which is a volatile storage device, as necessary. In the frozen state, the data read from the cine memory is reproduced and displayed on the screen as a moving image in accordance with a user operation. Diagnosis or measurement is performed based on such a moving image. It is also possible to transfer data acquired in real time or data stored in a cine memory to an external device (for example, a PC). A moving image is displayed by reproducing the received data in the external device. Based on this, diagnosis or measurement is executed. In addition to loop playback of moving images, frame advance playback may be performed in units of frames. Both the ultrasonic diagnostic apparatus and the external apparatus can be considered as an ultrasonic image processing apparatus.

  By the way, there are cases where an inspection is performed while comparing ultrasonic images of a plurality of views (angles). For example, in a stress echo test for diagnosing the heart in a state where exercise load or drug load is applied to a subject, a plurality of views can be obtained by changing the contact position and orientation of the probe for each load stage. A plurality of ultrasonic images (partial moving images) representing (for example, a parasternal long-axis cross section, a four-chamber cross section, etc.) are sequentially acquired, and diagnosis or measurement is performed based on these. Specifically, in each stage, a moving image over a plurality of heartbeats (for example, three or four heartbeats), that is, a frame sequence (a reception frame sequence or a display frame sequence) is acquired for each view. Then, for example, for each view, a frame sequence (partial frame sequence) for one heartbeat used for diagnosis or measurement is selected afterwards from the acquired frame sequences. Then, for example, a plurality of partial frame sequences corresponding to a plurality of combinations are loop-reproduced simultaneously and in parallel. By contrast-observing the contents of a plurality of reproduced moving images, the function or disease of the heart is diagnosed.

  In Patent Literature 1, a user gives a rank to each partial frame sequence included in a frame sequence acquired in a stress echo examination, and a portion to be diagnosed for each combination of stage and view based on the rank Selecting a frame sequence is disclosed. This is to manually specify a diagnosis target.

JP-A-2005-304758

  In the stress echo inspection described above, it is desirable to quickly acquire a plurality of frame sequences corresponding to a plurality of views for each stage. In particular, after applying a load on the subject (stage immediately after loading), in order not to overlook myocardial motility abnormalities that disappear early, a plurality of frame sequences corresponding to a plurality of views are maintained while maintaining real-time operation. Need to get quickly and continuously. In that case, there is no marker indicating a break between views on the acquired frame sequence. A frame sequence for a plurality of heartbeats acquired for each view is composed of a plurality of partial frame sequences, for example, with one heartbeat as a unit, and among them, the best partial frame sequence that can be a diagnostic target, the diagnostic target Include a partial frame sequence that can be a candidate for the next point, a partial frame sequence that is inappropriate as a diagnosis target, and the like.

  Under the above-described circumstances, conventionally, for each stage, a frame sequence is reproduced, a series of displayed moving images is observed, and a visual determination is performed to determine a moving image, that is, a partial frame to be diagnosed for each view. The columns were identified sequentially.

  In the method based on visual judgment as described above, the burden on the inspector is inevitably large and takes time. There is also a problem that the start of image contrast diagnosis is delayed. It can also be pointed out that the method depends on the subjectivity of the examiner. Those problems may also occur in other inspections that are continuously acquired including those that do not require a plurality of types of moving images.

  An object of the present invention is to select a partial frame sequence that is a candidate for diagnosis for each view from a frame sequence in which a view is switched halfway without requiring a special burden on an examiner.

  The ultrasonic image processing apparatus according to the present invention includes a selection unit that selects a representative frame representing each partial frame sequence from a frame sequence including a plurality of partial frame sequences acquired continuously while switching views. For each of the representative frames, calculation means for calculating distance information indicating a relationship between the view when the representative frame is acquired and a plurality of specified views, and a plurality of distance information calculated for the plurality of representative frames. And a specifying unit that specifies a partial frame sequence that is a candidate for diagnosis for each of the specified views from among the plurality of partial frame sequences.

  According to the above configuration, a representative frame is selected from each partial frame sequence in the frame sequence, and distance information is calculated for each representative frame. The distance information is information indicating the relationship between the representative frame and a plurality of specified views. In other words, information indicating the degree or probability that the view (execution view) when the representative frame is acquired corresponds to each specified view. It is. Therefore, if a plurality of distance information calculated for a plurality of representative frames are compared with each other, it is possible to select a representative frame that is highly likely to belong to each view, that is, a partial frame sequence, as a candidate for diagnosis. For example, for a certain representative frame, the specified view that is evaluated to be the closest is specified as the view when the representative frame is acquired. Although it may be possible to determine a view to which all frames constituting an individual partial frame sequence belong, in that case, a large amount of calculation is required. On the other hand, according to the above configuration, since it is only necessary to determine the view for the representative frame selected from each partial frame sequence, the amount of calculation when specifying the view can be greatly reduced. The partial frame sequence is a frame sequence for forming a moving image for one heartbeat, for example. In that case, the representative frame is preferably a frame acquired in a predetermined time phase of the heartbeat cycle. One or a plurality of frames may be selected as a representative frame from the partial frame sequence.

  Preferably, the calculation means calculates a plurality of distances corresponding to a plurality of specified views as the distance information for each representative frame, and the plurality of distance information calculated for the plurality of representative frames includes a distance matrix. The specifying unit specifies a partial frame sequence that is a candidate for diagnosis for each of the specified views based on the distance matrix.

  In this configuration, the distance matrix indicates a relationship between a plurality of specified views and a plurality of partial frame sequences as a table, in which a plurality of distances calculated for a plurality of partial frames for each specified view ( Distance column). Therefore, it is possible to easily compare a plurality of distances for each prescribed view on the distance matrix. The individual distances indicate numerically how close the view when obtaining the representative frame is to each specified view. For example, when the subspace method is applied as the image classification method, the distance is a distance calculated between the input image and each subspace. When a simple correlation method is applied as the image classification method, the distance is a correlation value.

  Preferably, the specifying unit includes a minimum distance specifying unit that specifies a minimum distance for each of the specified views in the distance matrix, and a partial frame sequence including a representative frame corresponding to the minimum distance for each view. And a partial frame sequence specifying means for specifying as follows. When there are a plurality of partial frame sequences in the frame sequence for each view, basically, one partial frame sequence is specified as a diagnosis target candidate of the view from among them. However, a plurality of partial frame sequences may be specified as diagnosis target candidates of the view. Depending on the judgment of the examiner, the diagnosis target candidates may be sequentially switched in order of distance in units of partial frames.

  Preferably, a means for performing a sorting process on the distance column for each of the specified views on the distance matrix and obtaining a distance column after the sorting process for each of the specified views; Means for controlling the display order of the representative frames according to the distance sequence. The distance string sorting process according to the size of the distance corresponds to a process of rearranging a plurality of representative frames, that is, a plurality of partial claim strings, in a suitable order as candidates for diagnosis. Normally, a partial frame sequence including a representative frame for which the minimum distance (best distance) is calculated is automatically selected as a diagnostic exercise candidate, but according to the above configuration, a diagnostic target candidate automatically selected by an inspector In the case of rejecting, it is possible to sequentially display a plurality of representative frames according to the representative frame display order. In that case, a plurality of partial frame sequences may be sequentially displayed as moving images. Thereby, the partial frame sequence used for diagnosis can be selected in consideration of the user's visual judgment. Even in such a case, since the representative frame display order is automatically determined based on the distance, the burden on the user can be reduced and the time required for the selection can be shortened.

  Preferably, the distance matrix is configured in each prescribed stage of stress echo examination, the partial frame sequence that is the candidate for diagnosis is specified for each combination of the prescribed stage and the prescribed view, and the ultrasonic image processing apparatus further includes: Means for displaying a two-dimensional table showing a relationship between a plurality of prescribed stages and a plurality of prescribed views in the stress echo examination; and a partial frame sequence of the diagnosis target candidates in a plurality of cells constituting the two-dimensional table Means for individually identifying and displaying a cell corresponding to the specified combination of the specified stage and the specified view. According to the above configuration, it is possible to quickly confirm whether or not a candidate for diagnosis has already been specified for each combination of a stage (a prescribed stage) and a view (a prescribed view) after the capturing step is completed. That is, if there is such a combination that has failed to be identified, it can be quickly identified.

  Preferably, the image processing apparatus includes a dividing unit that divides the frame sequence into the plurality of partial frame sequences according to a heartbeat cycle, and the selection unit selects a frame acquired at a predetermined time phase for each partial frame sequence as a representative frame. The cardiac cycle is obtained from, for example, an electrocardiogram signal, and can be obtained by moving image analysis or the like.

  ADVANTAGE OF THE INVENTION According to this invention, the partial moving image used as a diagnostic object candidate for every view can be selected from the moving image from which a view switches in the middle.

1 is a schematic configuration diagram of an ultrasonic diagnostic apparatus according to the present embodiment. It is a figure which shows the example of the calculated determination value. FIG. 3 is a partial extraction diagram of FIG. 2. It is a figure which shows the example of a display screen. It is a flowchart which shows the flow of operation | movement of the ultrasonic diagnosing device which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described. In the present embodiment, an example in which the ultrasonic diagnostic apparatus 10 is used for cardiac stress echo examination will be described.

  FIG. 1 is a schematic configuration diagram of an ultrasonic diagnostic apparatus 10 as an ultrasonic image processing apparatus according to the present embodiment. The ultrasonic diagnostic apparatus 10 is a medical device that is generally installed in a medical institution such as a hospital and performs ultrasonic diagnosis on a subject.

  The probe 12 is an ultrasonic probe that transmits and receives ultrasonic waves to and from a subject. The probe 12 has a transducer array composed of a plurality of transducers. A plurality of transmission signals from the transmission / reception unit 14 are supplied to the plurality of transducers. Thereby, an ultrasonic beam is formed. The plurality of vibration elements constituting the transducer array receive the reflected echo from the transmission / reception region, and thereby a plurality of reception signals are output to the transmission / reception unit 14.

  The probe 12 is a movable body that is held and operated by an inspector. In order to form ultrasound images representing various views of the heart under examination, the examiner applies the probe at various positions on the subject's chest surface at various angles. For example, when acquiring an ultrasonic image of the long-axis cross section of the heart of the heart, the probe 12 is brought into contact with the sternum at the left edge of the third or fourth intercostal sternum in a direction of about 60 degrees. In addition, when acquiring an ultrasound image of the parasternal short-axis cross section of the heart, the probe 12 is rotated 90 degrees clockwise from the angle at which the para-sternal long-axis cross section is acquired at the position where the para-sternal long-axis cross section is acquired. The contact is made at the rotated angle. In the stress echo examination, the main sections of the echocardiogram are the parasternal long axis section, the parasternal short axis section, the apex 2-chamber section, the apex 3-chamber section (apical section long-axis section), and Five ultrasonic images (moving images) representing five views of the apex 4 cavity cross section are acquired.

  The transmission / reception unit 14 transmits a plurality of transmission signals for exciting the plurality of transducers included in the probe 12 during transmission. On the other hand, at the time of reception, the transmission / reception unit 14 forms beam data by performing phasing addition processing on a plurality of reception signals output from a plurality of transducers. Along with electronic scanning of the ultrasonic beam, a plurality of beam data are sequentially output. A plurality of beam data for one frame is obtained per electronic scan. Each beam data is composed of a plurality of reflected echo signals arranged in the depth direction. As described above, the transmission / reception unit 14 has functions of a transmission beamformer and a reception beamformer.

  In this embodiment, the received frame sequence (received frame data sequence) output from the transmission / reception unit 14 is output to the cine memory 16 in addition to being output to the image forming unit 18. First, the latter will be described. The cine memory 16 has a ring buffer structure, for example, in which received frames inputted in time series are sequentially stored. That is, the received frame sequence from the latest to the past certain period is always stored. Normally, a frame number and a beam number are assigned to individual beam data constituting a reception frame, and thereby individual beam data is managed. In the present embodiment, information specifying the relationship between the acquisition time phase of each received frame and the time phase of an electrocardiographic signal described later is also managed on the cine memory.

  When the store instruction is received by the user, the received frame sequence stored in the cine memory 16 is transferred to the nonvolatile storage unit 24. In the stress echo inspection, for example, a store instruction is input after completion of capturing of each stage. However, for example, the received frame sequence may be transferred and stored in conjunction with the freeze operation after the completion of capturing of each stage without passing through the store operation. The classification process may be automatically started, and the processing result may be transferred and stored. Instead of the cine memory, an image memory that takes in a necessary frame sequence may be used, or a cine memory may be provided at the subsequent stage of the image forming unit 18 described below.

  The image forming unit 18 is, for example, a digital scan converter (DSC), and converts the received frame sequence from the transmission / reception unit 14 into a display frame sequence. Specifically, it has a coordinate conversion function, an interpolation processing function, and the like. In the illustrated configuration example, the received frame sequence read from the cine memory 16 and the received frame sequence read from the storage unit 24 can be sent to the image forming unit 18. In the present embodiment, the image forming unit 18 forms a B-mode image as an ultrasonic image. Specifically, as already mentioned, the image forming unit 18 forms a display frame sequence (B-mode moving image) based on the received frame sequence. As the type of ultrasonic image, a two-dimensional blood flow image (color Doppler image) showing blood flow motion in the subject may be formed.

  The display processing unit 20 performs processing for causing the display unit 22 to display the B-mode image formed by the image forming unit 18. For example, it has a graphic image synthesis function, a color processing function, and the like. In the stress echo examination, the display mode of the ultrasound image is changed according to the processing result of the determination value calculation unit 36 or the heartbeat frame sequence extraction unit 38 described later. The display processing unit 20 performs processing for causing the display unit 22 to display a processing result in the ultrasonic diagnostic apparatus 10, for example, a display indicating a view specified by the heartbeat frame sequence extracting unit 38 (which will also be described later). The display unit 22 is configured by a liquid crystal display, for example.

  The storage unit 24 is non-volatile and includes, for example, a hard disk, ROM, or RAM. The storage unit 24 stores a program for operating each component of the ultrasonic diagnostic apparatus 10. Further, the received frame sequence transferred from the cine memory 16 when a store instruction is received from the user is stored. Further, the storage unit 24 stores the calculation result of the ultrasonic diagnostic apparatus 10 and the like. The reference data group 34 stored in the storage unit 24 will be described later.

  The control unit 26 can be realized by, for example, hardware such as a CPU or a microprocessor, or cooperation with software (program) that defines the operation of the CPU or the microprocessor. The control unit 26 controls each component of the ultrasonic diagnostic apparatus 10. The input unit 28 includes buttons, switches, trackballs, and the like, and is used for inputting user instructions to the control unit 26. The user uses the input unit 28 to input store start and stop instructions and the like to the control unit 26.

  The electrocardiograph 30 outputs heartbeat data indicating the state of the heartbeat of the subject. For example, the electrocardiograph 30 has an electrode, and the electromotive force of the subject is measured by attaching the electrode to the subject. An electrocardiographic signal indicating the measured electromotive force is output as heartbeat data. The heartbeat data is stored in the cine memory 16 in association with the frame data. Further, it is stored in the storage unit 24 together with the frame data by a store instruction.

  The frame sequence processing unit 32 divides the reception frame sequence formed by the image forming unit 18 into a plurality of partial frame sequences based on the heartbeat data. Further, the frame sequence processing unit 32 specifies a representative frame for each partial frame sequence based on the heartbeat data. Details of the processing of the frame sequence processing unit 32 will be described later.

  The reference data group 34 stored in the storage unit 24 is data indicating a standard image of each specified view. In the present embodiment, the reference data group 34 includes reference data (PLAX) 34a that is a standard image of a parasternal long-axis cross section, reference data (PSAX) 34b that is a standard image of a para-sternal short-axis cross section, and a two-chamber apical section. Reference data (A2CH) 34c, which is a standard image of the apex, reference data (A3CH) 34d which is a standard image of the cross section of the apex 3 cavities, and reference data (A4CH) 34e which is a standard image of the cross section of the apex 4 cavities Contains data.

  A determination value calculation unit 36, which will be described later, calculates the distance between each representative frame and each reference data. In the present embodiment, the subspace method is used to calculate the determination value. Therefore, as reference data, for example, a partial space calculated by principal component analysis or the like from a plurality of standard images of a specified view is stored. Alternatively, when image comparison is simply performed for calculation of the determination value, a standard image of each specified view may be simply stored as reference data.

  The determination value calculation unit 36 calculates distance information indicating the relationship between each reference data included in the reference data group 34 and the representative frame. Specifically, the relationship between each reference data and the representative frame is a distance between the representative frame and each partial space as each reference data. That is, the distance information is an index indicating how much the representative frame is similar to each specified view (similarity). Details of the processing of the judgment value calculation unit 36 will be described later with reference to FIG.

  Based on the distance information calculated by the determination value calculation unit 36, the heartbeat frame sequence extraction unit 38 extracts a heartbeat frame sequence as a partial frame sequence that is a candidate for diagnosis for each view from the frame sequence formed by the image forming unit 18. Extract. Details of the processing of the heartbeat frame sequence extraction unit 38 will be described later with reference to FIGS.

  In the present embodiment, the ultrasonic diagnostic apparatus 10 is used as the ultrasonic image processing apparatus. However, as the ultrasonic image processing apparatus, a computer other than the ultrasonic diagnostic apparatus 10, for example, a personal computer (PC) may be used. Is possible. In this case, the computer receives the frame sequence formed by the ultrasonic diagnostic apparatus and performs the above processing.

  Note that, among the components shown in FIG. 1 (respectively assigned parts), the transmission / reception unit 14, the image forming unit 18, the display processing unit 20, the frame sequence processing unit 32, the determination value calculation unit 36, and the heart rate frame sequence extraction unit Each unit 38 can be realized by using hardware such as an electric / electronic circuit or a processor, for example, and a device such as a memory may be used as necessary in the realization. In addition, functions corresponding to the above-described units may be realized by cooperation between hardware such as a CPU, a processor, and a memory, and software (program) that defines the operation of the CPU and the processor.

  With the above configuration, a B-mode image is formed in the ultrasonic diagnostic apparatus 10. Specifically, when the stress echo examination is started, first, at stage 1 (at rest), the ultrasound beam is transmitted to the heart of the subject while changing the position and angle of the probe 12, that is, while switching the view. Scanned. As a result, for each of a plurality of views, three or four heartbeat-specific frame sequences are formed, and a stage frame sequence including them is formed. In the present embodiment, each stage frame sequence includes a plurality of view-specific frame sequences corresponding to a parasternal long axis section, a parasternal short axis section, an apex 2-chamber section, an apex 3-chamber section, and an apex 4-chamber section. Is included. Similarly, stage frame trains are formed at stage 2 (at peak load) and stage 3 (at recovery).

  Details of the process of extracting a heart rate data sequence as a diagnosis target candidate from the stage frame sequence will be described below.

  The frame sequence processing unit 32 divides the stage frame sequence formed by the image forming unit 18 into a plurality of heart rate frame sequences as partial frame sequences based on the heart rate data. In the present embodiment, a frame sequence from a frame (R wave frame) formed from frame data acquired at the timing of the R wave to a frame immediately before the next R wave frame is a heartbeat frame sequence. Therefore, the stage frame sequence is divided into a plurality of heart rate frame sequences in units of one heart rate. Note that a frame sequence for a plurality of heartbeats may be divided as a unit.

  Further, the frame sequence processing unit 32 selects a representative frame for each heartbeat frame sequence. In the present embodiment, the frame sequence processing unit 32 selects a frame formed from frame data acquired in a specific heartbeat time phase as a representative frame based on the heartbeat data. Specifically, a frame formed from frame data acquired at the timing when the R wave is detected (that is, the end diastole) is selected as a representative frame.

  The determination value calculation unit 36 determines the distance between the representative frame selected by the frame sequence processing unit 32 and each reference data included in the reference data group 34 (that is, the similarity between the representative frame and each specified view). Calculate the value set. In the present embodiment, since the reference data group 34 includes five reference data, the determination value calculation unit 36 calculates five determination values for one representative frame. In addition, as each reference data included in the reference data group 34, data corresponding to the time phase of the representative frame is prepared. As described above, the subspace method is used as the determination value calculation method. That is, a value indicating the distance between the feature amount extracted from each representative frame and each partial space indicating each specified view is calculated as a determination value. In the present embodiment, the determination value increases as the distance between the representative frame and the reference data decreases.

  When a standard image is prepared as reference data, the standard image similarity between the representative frame and each specified view may be calculated as a determination value. In this case, the similarity between the representative frame and each specified view is calculated using, for example, a pattern matching method.

  For each representative frame, a view of each representative frame can be specified by calculating a determination value set indicating a distance from each reference data. Specifically, by comparing each determination value included in the determination value set calculated for a certain representative frame, the reference data having the highest similarity with the representative frame is specified. Then, it can be specified that the view indicated by the specified reference data is the view of the representative frame.

  In this embodiment, the view of the identified representative frame is regarded as the view of the heartbeat frame sequence including the representative frame. A determination value set indicating the similarity to each reference data is calculated for all frames included in the frame sequence, the view of each frame is specified, and the heartbeat frame sequence of the candidate for diagnosis of each view is extracted. It is also possible in theory. However, if determination values are calculated or compared for all frames, the amount of calculation becomes enormous, which is practically difficult to implement. Thus, in the present embodiment, a view of the heartbeat frame sequence including the representative frame is specified by selecting a representative frame for each heartbeat frame sequence having a predetermined length and specifying the view of the representative frame. Thereby, the amount of calculation is reduced.

  Note that the determination value calculation unit 36 does not have to calculate a determination value set for all representative frames. For example, a heartbeat frame acquired during a view change or the like may be identified, and a determination value set may not be calculated for a representative frame of such a heartbeat frame sequence. In this case, the determination value calculation unit 36 performs image recognition processing on the first frame and the last frame in each heartbeat frame sequence, and determines whether or not both frames are the same view. If the view is different between the first frame and the last frame, it indicates that the view has changed in the middle of the heartbeat frame sequence. Therefore, since such a heartbeat frame sequence can be determined to be a heartbeat frame acquired during a view change or a probe movement, a determination value set is not calculated for a representative frame of the heartbeat frame sequence. May be.

  FIG. 2 is a diagram illustrating an example of the determination value calculated by the determination value calculation unit 36. FIG. 2 shows a representative frame sequence 60 in which a plurality of representative frames selected from the stage frame sequence by the frame sequence processing unit 32 are arranged from the left in order of acquisition time series. The representative frame sequence 60 includes a plurality of representative frames acquired for each view. For example, the representative frames 64a to 64c are frames of the parasternal long axis, the representative frames 66 and 70 are frames acquired during the rotation or movement of the probe, and the representative frames 68a to 68c are parasternal short axis cross sections. It is a frame. FIG. 2 shows a part of the representative frame row 60. Actually, the representative frame row 60 includes a frame of the apex 2-chamber section, a frame of the apex 3-chamber section, and a frame of the apex 4-chamber section. A frame is also included.

  The determination value calculation unit 36 calculates a determination value set indicating the distance from each reference data for each representative frame. Thereby, a matrix 62 as shown in FIG. 2 is formed. Each row of the matrix 62 corresponds to each reference data (each specified view). For example, the first row shows an evaluation value indicating the distance between each representative frame and the reference data (PLAX) 34a. As described above, in this embodiment, the determination value increases as the degree of similarity with the specified view increases. The determination value can take a value from 0 to 1 (when completely identical).

  By referring to the matrix 62 in the row direction, the heartbeat frame sequence extraction unit 38 can identify a representative frame that is the smallest in distance to each reference data, that is, most similar to each defined view. For example, when the maximum value among the determination values included in the row 70 a is “0.887” calculated with respect to the representative frame 64 b, the reference data (PLAX) among the representative frames included in the representative frame sequence 60. The representative frame having the smallest distance from 34a can be specified as the representative frame 64b. Therefore, in this case, the heartbeat frame sequence extraction unit 38 extracts a heartbeat frame including the representative frame 64b as the heartbeat frame sequence of the diagnosis target candidate of the parasternal long-axis cross section.

  Similarly, the heartbeat frame sequence extraction unit 38 refers to each determination value included in the sequence 70b and specifies the maximum determination value “0.889” of them. As a result, the representative frame having the shortest distance from the reference data (PSAX) 34b is identified as the representative frame 68b, and the heartbeat frame including this is extracted as a heartbeat frame sequence of the diagnosis target candidate of the parasternal short-axis cross section.

  In addition, the heartbeat frame sequence extraction unit 38 may specify a plurality of heartbeat frames of diagnosis target candidates by specifying the view of each representative frame. In this case, the heartbeat frame sequence extraction unit 38 refers to the matrix 62 in the column direction. For example, referring to each determination value included in the column 72a (that is, a determination value calculated between the representative frame 64a and each reference data), the determination value indicating the distance from the reference data (PLAX) 34a is “0. 866 ”, which is the maximum value in the determination value set calculated for the representative frame 64a. Therefore, the heartbeat frame sequence extraction unit 38 identifies the view of the representative frame 64a as a parasternal long-axis cross section. Similarly, the views of representative frames 64b and 64c are also identified as parasternal long axis cross sections. As described above, when a plurality of representative frames identified as the parasternal long-axis cross-sectional view are identified, a plurality of heartbeat frame sequences including each representative frame may be identified as candidates for diagnosis of the para-sternal long-axis cross-section. Good.

  Referring to the column 72b, the maximum determination value among the determination values calculated between the representative frame 66 and each reference data is the determination value “0... Calculated with the reference data (PSAX) 34b. 003 ". However, the determination value is very small, and it is not appropriate to specify the representative frame 66 as a parasternal short-axis cross-sectional frame. Therefore, when the maximum determination value is less than a predetermined value (for example, 0.700) in the determination value set calculated between a certain representative frame and each reference data, the determination value calculation unit 36 The view of the representative frame is identified as “other view”, ie. This process reduces the possibility of erroneous determination of the view of the representative frame.

  Other methods may be adopted as a technique for reducing the possibility of erroneous view determination. For example, when the difference between the maximum determination value and the second largest determination value among the determination values calculated between a certain representative frame and each reference data is less than a predetermined value, the view of the representative frame is expressed as “ It may be specified as “other views”.

  FIG. 3 is a partial extraction diagram of FIG. As shown in FIG. 3, in this example, there are three representative frames determined to be parasternal long-axis cross sections. In this case, the determination value calculation unit 36 sorts the determination value set 70c calculated between the reference data (PLAX) 34a and the representative frames 64a, 64b, and 64c included in the parasternal long axis section group. Then, the display processing unit 20 causes the display unit 22 to display three heartbeat frame sequences including the representative frames 64a, 64b, and 64c in the order based on the sorted determination value set. Specifically, a moving image including the representative frame 64b, a moving image including the representative frame 64a, and a moving image including the representative frame 64c are displayed in this order. Accordingly, the heartbeat frame to be diagnosed can be selected from among a plurality of heartbeat frame sequences that are preferably displayed by the user.

  FIG. 4 is a diagram illustrating an example of a display screen on which a heartbeat frame sequence of a candidate for diagnosis is displayed. When the heartbeat frame sequence extraction unit 38 specifies a heartbeat frame sequence that is a candidate for diagnosis, the display processing unit 20 enlarges and displays the representative frame of the heartbeat frame sequence on the upper left of the screen. In this example, the representative frame 64b is displayed as a candidate for diagnosis. The heartbeat frame sequence including the representative frame 64b may be continuously switched and displayed in the same part on the screen, and may be reproduced in a loop as a moving image. Further, switching between a moving image and a still image may be possible in accordance with a user instruction.

  At the bottom of the screen, a plurality of acquired heartbeat frame sequences are displayed as thumbnails in the order of acquisition time series. At the bottom of the screen are some representative frames included in the acquired representative frame sequence 60 (see FIG. 2), and the display range of the representative frame sequence 60 can be switched by the scroll buttons 82a and 82b or the slider 84. In FIG. 4, a representative frame 64a, a representative frame 64b, and a representative frame 64c are displayed as part of the representative frame row 60. As for thumbnails, the frame sequence including each representative frame may be continuously switched and displayed as a moving image in a loop. Further, switching between a moving image and a still image may be possible in accordance with a user instruction. In the thumbnail display, a frame 86 indicating that is displayed on the representative frame 64b selected as a candidate for diagnosis.

  The user visually checks the representative frame 64b specified as a candidate for diagnosis or a heartbeat frame sequence (heartbeat motion image) including the representative frame 64b, and determines whether the heartbeat frame sequence is appropriate as a motion image to be diagnosed. . If not appropriate, another heartbeat frame can be selected from the thumbnail display as a moving image to be diagnosed. If there is no instruction from the user, the heartbeat frame sequence specified as the diagnosis target candidate may be determined as it is as the heartbeat frame sequence to be diagnosed.

  On the upper right of the screen, a table 88 is displayed with each stage of stress echo as a row and each view as a column. The table 88 is displayed to identify the combination of the stage and the view from which the heartbeat frame sequence of the candidate for diagnosis is extracted. Table 88 shows views in which heartbeat frame sequences of candidate diagnosis targets are extracted at each stage of rest (BASE), peak load (PEAK), and recovery (RECO) of the stress echo test. For example, at rest, a stage frame sequence including a frame of each view is acquired by the user, and the above processing is performed on the stage frame sequence by the determination value calculation unit 36 or the heart rate frame sequence extraction unit 38, and the parasternal long axis When the heartbeat frame sequence of the candidate for diagnosis of the cross section is extracted, a check mark as an identification index is displayed in the cell 88a of the BASE row PLAX column. Similarly, when the heartbeat frame sequence of the candidate for diagnosis of the parasternal short-axis cross-section, the apex 2-chamber cross-section, the apex 3-chamber cross-section (the apex long-axis cross-section), and the apex 4-chamber cross-section is extracted at rest, A check mark is displayed in the corresponding cell. Note that information indicating which stage's frame sequence the acquired stage frame sequence is input by the user. The table 88 allows the user to grasp at a glance the combination of the stage and the view from which the heartbeat frame sequence of the candidate for diagnosis is extracted.

  FIG. 5 is a flowchart showing a flow of operations of the ultrasonic diagnostic apparatus 10 according to the present embodiment. The flowchart of FIG. 5 will be described with reference to FIG.

  In step S10, when the stress echo examination is started, in each stage, the user touches the probe 12 while changing the position or angle of the probe 12, and consists of a plurality of frames acquired in a plurality of views. A stage frame data string is acquired. Each stage frame data string is stored in the storage unit 24 in accordance with a user store instruction.

  The image forming unit 18 forms a plurality of stage frame sequences based on the individual stage frame data sequences stored in the storage unit 24. Hereinafter, processing for one stage frame sequence will be described.

  In step S12, the frame sequence processing unit 32 divides the formed stage frame sequence into a plurality of heart rate frame sequences based on the heart rate data. Specifically, a frame sequence from the R wave frame to the next R wave frame is defined as one heartbeat frame sequence.

  In step S <b> 14, the determination value calculation unit 36 calculates a determination value set indicating the distance from each of the plurality of reference data for one representative frame.

  In step S <b> 16, the determination value calculation unit 36 determines whether determination value sets for all representative frames have been calculated. If determination value sets for all the representative frames have not been calculated, the process returns to step S14, and the processes from step S14 to S16 are performed for the other representative frames. A matrix 62 (see FIG. 2) is constructed by calculating a determination value set for each representative frame.

  In step S <b> 18, the heartbeat frame sequence extraction unit 38 specifies a representative frame having the smallest distance from each reference data based on the matrix 62. Then, for each specified view, a heartbeat frame sequence including the specified representative frame is specified as a diagnosis target candidate.

  In step S20, the display processing unit 20 displays a two-dimensional table having each stage and view as dimensions, and uses an identification index in a cell corresponding to the combination of the stage and view from which the heartbeat frame sequence of the candidate for diagnosis is extracted. A certain check mark is displayed.

  The processes from steps S12 to S20 are executed for the stage frame sequence corresponding to each stage of the stress echo examination.

  Through the above processing, a heartbeat frame sequence that is a candidate for diagnosis can be specified for each view from a stage frame sequence including frames acquired in a plurality of views. Since this process is performed for each stage frame sequence, the heartbeat frame sequence of the diagnosis target candidate of each view is specified in each stage of the stress echo examination. Thereby, the user can easily select a heartbeat frame sequence used for diagnosis. In addition, it is possible to select a diagnosis target moving image that does not depend on the user's subjectivity.

  DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus, 12 Probe, 14 Transmission / reception part, 16 Cine memory, 18 Image formation part, 20 Display processing part, 22 Display part, 24 Storage part, 26 Control part, 28 Input part, 30 Electrocardiograph, 32 Frame sequence Processing unit, 34 reference data group, 36 determination value calculation unit, 38 heart rate frame string extraction unit.

Claims (7)

Selecting means for selecting a representative frame representing each partial frame sequence from a frame sequence including a plurality of partial frame sequences acquired continuously while switching views;
For each of the representative frames, calculation means for calculating distance information indicating a relationship between the view when the representative frame is acquired and a plurality of specified views;
Based on a plurality of distance information calculated for the plurality of representative frames, a specifying unit that specifies a partial frame sequence that is a candidate for diagnosis for each of the specified views from the plurality of partial frame sequences;
An ultrasonic image processing apparatus comprising: The calculation means calculates a plurality of distances corresponding to a plurality of specified views as the distance information for each representative frame,
A plurality of distance information calculated for the plurality of representative frames constitutes a distance matrix;
The specifying unit specifies a partial frame sequence that is a candidate for diagnosis for each of the specified views based on the distance matrix.
The ultrasonic image processing apparatus according to claim 1, wherein: The specifying means is:
Minimum distance specifying means for specifying a minimum distance for each of the prescribed views in the distance matrix;
A partial frame sequence specifying means for specifying a partial frame sequence including a representative frame corresponding to the minimum distance for each view as the diagnosis target candidate;
including,
The ultrasonic image processing apparatus according to claim 2, wherein: Means for performing a sorting process on the distance column for each of the specified views on the distance matrix, and obtaining a distance column after the sorting process for each of the specified views;
Means for controlling a representative frame display order according to the distance sequence after the sorting process for each of the defined views;
including,
The ultrasonic image processing apparatus according to claim 2 or 3, wherein The distance matrix is configured in each prescribed stage of the stress echo examination, and a partial frame sequence that is the candidate for diagnosis is specified for each combination of the prescribed stage and the prescribed view
The ultrasonic image processing apparatus further includes:
Means for displaying a two-dimensional table showing the relationship between a plurality of prescribed stages and a plurality of prescribed views in the stress echo examination;
Means for processing so that cells corresponding to a combination of a prescribed stage and a prescribed view in which a partial frame sequence of the candidate for diagnosis is specified among a plurality of cells constituting the two-dimensional table are individually identified and displayed When,
including,
The ultrasonic image processing apparatus according to any one of claims 2 to 4, wherein the ultrasonic image processing apparatus is characterized in that: Dividing means for dividing the frame sequence into the plurality of partial frame sequences according to a heartbeat cycle;
The selecting means selects, as a representative frame, a frame acquired at a predetermined time phase for each partial frame sequence.
The ultrasonic image processing apparatus according to any one of claims 1 to 5, wherein Computer
Selecting means for selecting a representative frame representing each partial frame sequence from a frame sequence including a plurality of partial frame sequences acquired continuously while switching views;
For each of the representative frames, calculation means for calculating distance information indicating a relationship between the view when the representative frame is acquired and a plurality of specified views;
Based on a plurality of distance information calculated for the plurality of representative frames, a specifying unit that specifies a partial frame sequence that is a candidate for diagnosis for each of the specified views from the plurality of partial frame sequences;
Program to function as.