JP2010119587A - Ultrasonograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonograph which can simply detect the dislocation of an ultrasonic probe during scanning. <P>SOLUTION: The ultrasonograph 1 generates reference tomogram data in a plurality of time phases in a reference cross-section of an intracorporeal region while referring to the varying condition of the intracorporeal region periodically varying and stores the reference tomogram data corresponding to the time phases. The ultrasonograph 1 sequentially generates tomogram data in a plurality of cross-sections including the reference cross-section. At that time, the ultrasonograph 1 identifies the time phase of the intracorporeal region when the reference cross-section is ultrasonically scanned on the basis of the varying condition of the intracorporeal region and chooses reference tomogram data corresponding to an identified time phase from among a plurality of stored reference tomogram data. The ultrasonograph 1 computes the value of a correlation between the tomogram data of the reference cross-section and the chosen reference tomogram data and presents information concerning the dislocation of the ultrasonic probe 2 on the basis of the correlation value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus that transmits an ultrasonic wave into a subject and receives the reflected wave to image the inside of the subject. In particular, the present invention relates to a technique for detecting a positional deviation of an ultrasonic probe that occurs during an ultrasonic scan.

  An ultrasonic diagnostic apparatus is used for diagnosis of a body part that periodically varies, such as the heart. In the ultrasonic diagnosis of the heart, a technique called electrocardiographic synchronization is widely used (see, for example, Patent Document 1). ECG synchronization is a diagnostic technique in which an ultrasound image is acquired while acquiring an electrocardiogram of a subject, and the ECG waveform and the ultrasound image are displayed synchronously. Thereby, it becomes possible to observe the state of the heart according to the time phase of the heart.

  In recent years, a technique called STIC (spatial-temporal image correlation) has attracted attention (see, for example, Patent Document 2). STIC, for example, performs measurement while moving (swinging, rotating, translating, etc.) an ultrasonic probe to generate a large number of tomographic image data of internal body parts. This is a technique for generating phase three-dimensional image data. By rendering each of these three-dimensional image data and displaying them sequentially, it is possible to observe a three-dimensional moving image of the body part.

  In general, an ultrasonic scan time in the STIC is considerably long. For example, when an ultrasound probe is inserted into the esophagus and the heart is observed (for example, see Patent Documents 3 and 4), considering the resolution in the rotation direction of the ultrasound probe, about 60 seconds are required to scan the entire heart. (That is, assuming that one heartbeat is 1 second and the resolution in the rotation direction is set to 3 degrees, 180 ÷ 3 = 60 seconds).

  As described above, when the scanning time becomes long, it is assumed that the position of the ultrasonic probe is shifted during scanning. When the position shift occurs, distortion occurs in the three-dimensional image or the three-dimensional moving image for each time phase.

  As a technique for coping with the positional deviation of the ultrasonic probe, for example, those described in Patent Documents 5 and 6 are known. In the technique described in Patent Document 5, the rotation angle at which the correlation value is maximized is obtained by calculating the correlation value with other tomographic image data while rotating the reference tomographic image data among the plurality of tomographic image data. The rotation processing is performed on the reference tomographic image data by this rotation angle. In the technique described in Patent Document 6, the position of the ultrasonic probe is detected by a position sensor, and the detection result is reflected in the volume data generation process.

JP 2008-1113799 A JP 2005-74225 A JP 2006-101901 A JP 2006-312103 A Japanese Patent Laid-Open No. 10-248844 JP 2007-244575 A

  As described above, despite the fact that various techniques for dealing with the positional deviation of the ultrasonic probe have been developed, an effective technique for STIC is not yet known. That is, the STIC involves a process of rearranging a plurality of tomographic image data, but it is unclear how the technique of Patent Document 5 is applied to the volume data of each time phase obtained through this process.

  In addition, when an ultrasonic probe is inserted into a body cavity and an inspection is performed, it is difficult to assume the use of an ultrasonic probe to which a position sensor is attached, and it is difficult to apply the technique of Patent Document 6.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an ultrasonic diagnostic apparatus capable of easily detecting a displacement of an ultrasonic probe during an ultrasonic scan. It is to provide.

  In order to achieve the above object, the invention described in claim 1 includes a detecting means for detecting a fluctuation state of a periodically changing body part, and an ultrasonic probe for scanning the body part with ultrasound, Each of a plurality of time phases included in one cycle of the fluctuation in a predetermined reference cross section of the internal body part while referring to the detected fluctuation state and generation means for generating tomographic image data based on the scan result Control means for causing the generating means to generate the reference tomographic image data, storage means for storing the generated reference tomographic image data and time phases in association with each other, and a plurality of cross sections including the predetermined reference cross section When the tomographic image data is sequentially generated by the generating unit, the predetermined reference cross section is scanned with the ultrasonic wave based on the fluctuation state detected by the detecting unit. Specifying means for specifying a time phase of the internal body part at the time, and selecting means for selecting reference tomographic image data corresponding to the specified time phase from among the plurality of stored reference tomographic image data, Calculation means for calculating a correlation value between the tomographic image data of the predetermined reference slice among the plurality of slices and the selected reference tomographic image data, and the ultrasonic probe based on the calculated correlation value Presenting means for presenting information relating to the positional deviation of the ultrasonic diagnostic apparatus.

  The ultrasonic diagnostic apparatus according to the present invention generates a plurality of time-phase reference tomographic image data in a reference cross section of a body part while referring to a periodically changing state of the body part, and generates each reference The tomographic image data and the time phase are stored in association with each other. Further, the ultrasonic diagnostic apparatus sequentially generates tomographic image data in a plurality of cross sections including the reference cross section. At this time, the ultrasonic diagnostic apparatus specifies the time phase of the internal body part when the reference cross section is scanned with ultrasound based on the fluctuation state of the internal body part, and the reference tomographic image data corresponding to the specified time phase Is selected from a plurality of stored reference tomographic image data. Then, the ultrasonic diagnostic apparatus calculates a correlation value between the tomographic image data of the reference cross section and the selected reference tomographic image data, and presents information on the positional deviation of the ultrasonic probe based on the correlation value.

  According to such an ultrasonic diagnostic apparatus, the correlation value of the image data in the reference cross section can be sequentially obtained and information on the positional deviation of the ultrasonic probe can be presented, so that the positional deviation of the ultrasonic probe during the ultrasonic scan can be simplified. Can be detected.

  An example of an embodiment of an ultrasonic diagnostic apparatus according to the present invention will be described in detail with reference to the drawings.

[Constitution]
A configuration example of the ultrasonic diagnostic apparatus according to this embodiment is shown in FIGS. 1 and 2. The ultrasonic diagnostic apparatus 1 includes an ultrasonic probe 2, a transmission / reception unit 3, a signal processing unit 4, a data storage unit 5, an image generation unit 6, an image storage unit 7, a control unit 8, a user interface (UI) 9, and image processing. Part 12 is provided.

  The ultrasonic diagnostic apparatus 1 also includes an electrocardiograph 20. The electrocardiograph 20 has the same configuration as the conventional one, acquires an electrocardiogram (electrocardiogram waveform) representing the dynamics of the subject's heart, and inputs it to the control unit 8. The electrocardiograph 20 is an example of the “detecting means” of the present invention, and detects a fluctuation part of a body part that fluctuates periodically, that is, the heart.

  As the ultrasonic probe 2, for example, a one-dimensional array probe or a two-dimensional array probe is used. The one-dimensional array probe includes a plurality of ultrasonic transducers arranged in one row, and can scan ultrasonic waves in the one-dimensional direction along the arrangement direction (scanning direction). The two-dimensional array probe includes a plurality of ultrasonic transducers arranged two-dimensionally and can scan ultrasonic waves in a two-dimensional direction.

  The transducer unit 2a of the ultrasonic probe 2 includes an acoustic lens, an acoustic matching layer, an electrode, a backing material, and the like, as well as a plurality of ultrasonic transducers. The transducer unit 2 a transmits an ultrasonic wave based on the electrical signal from the transmission / reception unit 3. Furthermore, the transducer unit 2a receives the reflected wave from the subject of the ultrasonic wave.

  The ultrasonic probe 2 is provided with a moving mechanism 2b. The moving mechanism 2b moves the vibrator part 2a. The moving mechanism 2b may rotate the vibrator unit 2a, swing it, or move it in parallel. In addition, the movement aspect of the vibrator | oscillator part 2a by the moving mechanism 2b is not limited to these. By performing ultrasonic scanning while moving the ultrasonic probe 2 by the moving mechanism 2b, it is possible to scan a three-dimensional region in the subject. As the moving mechanism 2b, for example, those described in Patent Documents 3 and 4, or those described in Japanese Patent Application Laid-Open Nos. 2007-301030, 2008-73085, and 2008-99732 are arbitrary. The configuration of can be adopted.

  When a two-dimensional array probe is used, it is not necessary to provide the moving mechanism 2b as described above because the three-dimensional region in the subject can be ultrasonically scanned by itself.

  The transmission / reception unit 3 includes a transmission unit and a reception unit. The transmission / reception unit 3 supplies an electric signal to the transducer unit 2a to generate an ultrasonic wave. The transducer part 2a receives the reflected wave of the generated ultrasonic wave and outputs an electric signal (echo signal). The transmission / reception unit 3 receives this echo signal.

  The transmission unit of the transmission / reception unit 3 includes a clock generation circuit, a transmission delay circuit, a pulsar circuit, and the like (not shown). The clock generation circuit generates a clock signal that determines the transmission timing and transmission frequency of the ultrasonic signal. The transmission delay circuit performs transmission focus with a delay when transmitting ultrasonic waves. The pulsar circuit is provided with pulsars corresponding to the number of individual paths (channels) corresponding to each transducer, generates a drive pulse at a delayed transmission timing, and supplies an electrical signal to each transducer of the ultrasonic probe 2 To do.

  The reception unit of the transmission / reception unit 3 includes a preamplifier circuit, an A / D conversion circuit, a reception delay circuit, an addition circuit, and the like (not shown). The preamplifier circuit amplifies the echo signal output from each transducer of the ultrasonic probe 2 for each reception channel. The A / D converter circuit A / D converts the amplified echo signal. The reception delay circuit gives a delay time necessary for determining the reception directivity to the echo signal after A / D conversion. The adder circuit adds the echo signals given the delay time. By this addition processing, the reflection component from the direction corresponding to the reception directivity is emphasized. The signal added by the transmission / reception unit 3 is called RF data or the like.

  The signal processing unit 4 includes a B mode processing unit. The B-mode processing unit executes an imaging process of the amplitude information of the echo signal, and generates B-mode ultrasound raster data (tomographic image data) from the echo signal. More specifically, the B-mode processing unit performs band-pass filter processing on the reception signal sent from the transmission / reception unit 3, detects the envelope of the output signal, and logarithmically converts the detected data The compression process is applied. Further, the signal processing unit 4 may include a Doppler processing unit. For example, the Doppler processing unit extracts a Doppler shift frequency component by phase-detecting a signal sent from the transmission / reception unit 3, and generates a Doppler frequency distribution representing a blood flow velocity by performing FFT processing on the extracted component. . Furthermore, the signal processing unit 4 may include a CFM (Color Flow Mapping) processing unit. The CFM processing unit visualizes blood flow information and generates color ultrasonic raster data. Blood flow information is obtained as binarized information such as speed, distribution, and power. The signal output from the transmission / reception unit 3 is processed by one of the processing units. The signal processing unit 4 outputs the ultrasonic raster data after the signal processing to the data storage unit 5.

  The data storage unit 5 includes a storage device such as a memory or a hard disk, and stores ultrasonic raster data generated by the signal processing unit 4.

  The image generation unit 6 reads the ultrasonic raster data from the data storage unit 5 and converts it into coordinate system data based on spatial coordinates (digital scan conversion). For example, the image generation unit 6 performs scan conversion processing on the signal-processed data output from the B-mode processing unit, so that B-mode image data (tomographic image data) representing the form of the tissue in the subject is obtained. Is generated. As an example, when a two-dimensional cross section (scan surface) of a subject is scanned with ultrasound, the image generation unit 6 generates tomographic image data representing the form of the tissue on the scan surface. The image generation unit 6 outputs the tomographic image data to the image storage unit 7. In addition, when the tomographic image of the subject is displayed live, the image generation unit 6 outputs the tomographic image data to the control unit 8.

  The image storage unit 7 includes a storage device such as a memory and a hard disk, and stores tomographic image data from the image generation unit 6. In addition, the image storage unit 7 stores predetermined incidental information with the tomographic image data. The incidental information includes, for example, information indicating the date and time when the tomographic image data is acquired, information on the subject (patient information), and the like.

  When an electrocardiogram waveform is input from the electrocardiograph 20 (that is, when an electrocardiogram synchronization test is performed), the control unit 8 synchronizes the tomographic image data and the electrocardiogram waveform. That is, the control unit 8 associates each tomographic image data with a time phase at the timing when the data is acquired. The control unit 8 causes the image storage unit 7 to store the tomographic image data and the time phase information that are associated with each other.

  The control unit 8 receives the tomographic image data from the image generation unit 6 and causes the display unit 10 to display a tomographic image based on the tomographic image data. The control unit 8 reads the tomographic image data stored in the image storage unit 7 and causes the display unit 10 to display a tomographic image based on the tomographic image data. The configuration of the control unit 8 shown in FIG. 2 will be described later.

  The user interface (UI) 9 includes a display unit 10 and an operation unit 11. The display unit 10 includes a display device such as a CRT or a liquid crystal display. On the screen of the display unit 10, an ultrasonic image such as a tomographic image or a three-dimensional image, and various information related to the ultrasonic image are displayed. The display unit 10 is an example of the “presentation means” in the present invention. The method of presenting information by the presenting means is not limited to visual information. For example, the presenting means may output information in an arbitrary form such as voice information or print information. The operation unit 11 includes a pointing device such as a mouse or a trackball, various switches, various buttons, a keyboard, or a TCS (Touch Command Screen).

  As described above, the ultrasonic diagnostic apparatus 1 is configured to be able to scan a three-dimensional region in a subject with ultrasonic waves. When such three-dimensional scanning is performed, the signal processing unit 4 outputs the data (volume data) acquired by the three-dimensional scanning to the data storage unit 5, and the data storage unit 5 stores the volume data. The image generation unit 6 reads volume data from the data storage unit 5 (or image storage unit 7), and performs volume rendering on the volume data, thereby generating image data that three-dimensionally represents the tissue in the subject. . The image generation unit 6 can also generate image data (MPR image data) in an arbitrary cross section by performing MPR processing (Multi Planar Reconstruction) on the volume data.

  The image processing unit 12 performs various image processes on various image data. Examples of image data to be processed include tomographic image data and volume data. Examples of image processing include processing for setting an image region such as ROI (Region of Interest) in image data, processing for measuring the size of the image region, and the like. The three-dimensional (3D) image data synthesis unit 13 of the image processing unit 12 will be described later. The 3D image data composition unit 13 is an example of the “composition unit” of the present invention.

  With reference to FIG. 2, the configuration of the ultrasonic diagnostic apparatus 1 will be described in more detail. The control unit 8 includes a scan control unit 81, a time phase specifying unit 82, a data selection unit 83, a correlation calculation unit 84, a correlation determination unit 85, a display control unit 86, and an abnormality detection unit 87.

  The scan control unit 81 controls the moving mechanism 2b and the transmission / reception unit 3 to execute an ultrasonic scan on the subject. The scan control unit 81 can selectively execute a plurality of scan modes by controlling the moving mechanism 2b and the transmission / reception unit 3 in accordance with, for example, an ultrasonic scan mode designated by an operator. In particular, the scan control unit 81 performs three-dimensional scanning in the STIC.

  In the STIC executed by the ultrasound diagnostic apparatus 1, tomographic image data (reference tomographic image data) of a plurality of time phases of the subject's heart is acquired for a predetermined cross section (reference cross section) of the heart. This process is executed with reference to the electrocardiographic waveform obtained by the electrocardiograph 20. One or more predetermined numbers (for example, two) are set as the reference cross section. Moreover, the time phase can be set discretely or can be set continuously. As an example of the former, there is a method of recording characteristic timing such as P wave, Q wave, R wave, S wave, and T wave. As an example of the latter, there is a method of recording the time in the cardiac cycle. As an example of this, when a cardiac cycle (for example, RR interval) is 1 second, an elapsed time (0 second or more and less than 1 second) from a predetermined timing (R wave) can be recorded.

  The control unit 8 stores each reference tomographic image data in each generated reference cross section and its time phase in the image storage unit 7 in association with each other. The image storage unit 7 is an example of the “storage unit” of the present invention.

  In the STIC according to this embodiment, a plurality of cross sections including the reference cross section are sequentially scanned with ultrasonic waves. At this time, the heart state is detected by the electrocardiograph 20. When the tomographic image data in the plurality of cross sections are sequentially generated, the time phase specifying unit 82 detects the heart when each reference cross section is scanned with ultrasonic waves based on the electrocardiogram waveforms acquired in parallel. Specify the time phase of. The time phase specifying unit 82 is an example of the “specifying means” in the present invention.

  The process executed by the time phase specifying unit 82 will be described in more detail. Information representing the status of the ultrasound scan by the scan control unit 81 (scan status information) and the electrocardiogram waveform obtained by the electrocardiograph 20 are input to the time phase specifying unit 82 in real time. Further, when the tomographic image data is generated by executing the ultrasonic scan, the scan status information is associated with each generated tomographic image data as in the conventional case. Thereby, the cross-sectional position corresponding to each tomographic image data is specified (thus, the scan status information and the cross-sectional position information can be identified with each other).

  When the scan status information corresponding to the reference section is input, the time phase specifying unit 82 associates the time phase indicated in the electrocardiogram waveform input simultaneously with the scan status information. Thereby, the time phase when each reference cross section is scanned is specified. In addition, when the fluctuation timing of the heart is specified discretely (described above), for example, the time phase closest to the input timing of the scan status information can be associated.

  The data selection unit 83 selects reference tomographic image data corresponding to the time phase specified by the time phase specifying unit 82 from the plurality of reference tomographic image data stored in the image storage unit 7. In this process, the cross-sectional position of the time phase and the reference cross section specified by the time phase specifying unit 82 and the cross-sectional position of the time phase and the reference cross-section associated with the plurality of stored reference tomographic image data are collated. Can be executed more easily. The data selection unit 83 is an example of the “selection unit” in the present invention.

  The correlation calculation unit 84 calculates a correlation value between the tomographic image data of the reference cross section among the plurality of cross sections to be scanned and the reference tomographic image data selected by the data selection unit 83. As this arithmetic processing, for example, any conventional method such as the method described in Japanese Patent Laid-Open No. 5-7592, Japanese Patent Application Laid-Open No. 2003-235840, Japanese Patent Application Laid-Open No. 2008-1321994 can be used. . The correlation calculation unit 84 is an example of the “calculation unit” in the present invention.

  The correlation determination unit 85 determines whether the correlation value calculated by the correlation calculation unit 84 is equal to or less than a threshold value. This threshold is set in advance.

  The display control unit 86 controls the display unit 10 to display various information. In particular, the display control unit 86 displays information (position shift information) regarding the position shift of the ultrasonic probe 2 based on the correlation value calculated by the correlation calculation section 84 and the determination result by the correlation determination section 85. Examples of the positional deviation information include a correlation value itself, warning information based on a determination result (a message indicating that the positional deviation is large), and the like. Further, the positional deviation information may be displayed together with the image based on the tomographic image data.

  The abnormality detector 87 detects an abnormality of heart fluctuation based on the electrocardiogram waveform detected by the electrocardiograph 20. This process can be executed, for example, by analyzing an electrocardiogram waveform input from the electrocardiograph 20 and determining whether or not it corresponds to various waveform abnormalities recognized in the medical field.

  When an abnormality is detected by the abnormality detection unit 87, the control unit 8 controls the ultrasonic probe 2 or the like to generate new reference tomographic image data in each of the reference cross sections. The reference cross section is not set based on the subject's heart, but is determined according to the scan position by the ultrasonic probe 2. For example, when performing an ultrasonic scan while rotating the transducer part 2a, the reference cross section is set as a rotation angle (for example, 0 degrees, 90 degrees) from a predetermined reference position of the transducer part 2a.

  The ultrasonic diagnostic apparatus 1 includes an ultrasonic probe 2, a transmission / reception unit 3, a signal processing unit 4, a data storage unit 5, and an image generation unit 6 as examples of the “generation unit” of the present invention. The ultrasonic diagnostic apparatus 1 includes a scan control unit 81, a correlation determination unit 85, an abnormality detection unit 87, and the like as the “control unit” of the present invention.

[Operation]
The operation of the ultrasonic diagnostic apparatus 1 will be described.

[First operation example]
The flowchart shown in FIG. 3 represents an example of the operation of the ultrasonic diagnostic apparatus 1. In this operation example, a description will be given of a case where a heart STIC is performed using a transesophageal probe of the type in which the transducer section 2a rotates.

  First, the ultrasonic probe 2 is inserted into the esophagus of the subject and placed at an appropriate position. In this state, reference tomographic image data of the heart in a predetermined reference section is acquired for one heartbeat (one heart cycle) (S1).

  In this operation example, as shown in FIG. 4, tomographic image data for one heartbeat is acquired for each of the four reference cross sections A, B, C, and D. The reference section A and the reference section B, the reference section B and the reference section C, the reference section C and the reference section D, and the reference section D and the reference section A intersect at an angle of 45 degrees.

  The scanning of the reference cross sections A to D is executed as follows, for example. The electrocardiograph 20 acquires an electrocardiographic waveform of the subject and inputs it to the control unit 8 in real time. For example, the scan control unit 81 receives the R wave and starts scanning the reference cross section A, and inputs the next R wave and ends the scan. The scan control unit 81 scans the reference cross section A a plurality of times during this period (RR interval). Thereby, reference tomographic image data of a plurality of different time phases are obtained. The control unit 8 associates time phase information with each reference tomographic image data by referring to the electrocardiographic waveform input at the time of scanning for obtaining each reference tomographic image data. Then, the control unit 8 stores each reference tomographic image data associated with the time phase information in the image storage unit 7 in association with the identification information (reference sectional information) of the reference section A. The other reference slices B, C, and D are similarly scanned to acquire reference tomographic image data of a plurality of different time phases, and each reference tomographic image data is associated with the time phase information and the reference slice information. Store in the storage unit 7.

  Note that the scanning mode of each of the reference cross sections A to D is not limited to the above. For example, the start and end timing of the scan need not be determined with reference to the electrocardiogram waveform, and the scan timing of each reference section A to D can be associated with the electrocardiogram waveform (time phase). Any method can be applied.

  An example of the data structure of the reference tomographic image data stored in this way is shown in FIG. The image storage unit 7 stores folders 7a, 7b, 7c, and 7d corresponding to the reference sections A, B, C, and D. In the folder 7a of the reference section A, reference tomographic image data ai corresponding to each time phase i (i = 1, 2,..., N) is stored (double-sided arrows indicate the correspondence). The same applies to the other folders 7b, 7c, and 7d.

  When the reference tomographic image data is acquired, the main measurement is started (S2). This measurement may be started in response to an instruction (operation) from the operator, or may be automatically started in response to the acquisition of the reference tomographic image data.

  This measurement is performed as follows, for example. The scan control unit 81 controls the moving mechanism 2b as necessary to move the transducer unit 2a to a predetermined scan start position (for example, a position corresponding to the reference cross section A). At this time, the transducer unit 2a may be moved to a position immediately before the scan start position so that the transducer unit 2a rotates at a constant speed at the scan start position. The electrocardiograph 20 starts detecting an electrocardiographic waveform of the subject's heart. The electrocardiogram waveform may be detected continuously from step 1.

  The scan control unit 81 controls the transmission / reception unit 3 to cause the transducer unit 2a to start transmitting and receiving ultrasonic waves, and also controls the moving mechanism 2b to start rotation of the transducer unit 2a (S3). In this operation example, scanning is started from the reference cross section A shown in FIG. 4, and the transducer unit 2 a is rotated clockwise as viewed from the ultrasonic probe 2 side. Thereby, the reference cross sections A, B, C, and D are scanned in this order. Scanning can also be performed on cross sections other than the reference cross sections A to D (for example, a cross section between the reference cross section A and the reference cross section B). In particular, when three-dimensional image data is generated, scanning is performed on cross sections other than the reference cross sections A to D.

  As described above, the scan control unit 81 sequentially scans a plurality of cross sections (here, four or more cross sections) including the reference cross sections A to D while rotating the vibrator unit 2a as described above. Thereby, the tomographic image data in the plurality of cross sections is sequentially generated (S4). The image generation unit 6 sequentially inputs these tomographic image data to the control unit 8.

  The time phase specifying unit 82 specifies the time phase of the heart when each of the reference sections A to D is scanned based on the electrocardiogram waveform input from the electrocardiograph 20 (S5).

  Next, the data selection unit 83 selects reference tomographic image data corresponding to the time phase specified by the time phase specifying unit 82 from the reference tomographic image data stored in the image storage unit 7 (S6). This process is executed by collating the above-described reference cross-section information with the time phase information.

  Subsequently, the correlation calculation unit 84 calculates a correlation value between the tomographic image data of the reference cross section obtained by the main measurement and the reference tomographic image data selected by the data selection unit 83 (S7).

  The display control unit 86 displays the calculated correlation value on the display unit 10 (S8). At this time, the image based on the reference tomographic image data obtained in step 1 and the image based on the reference tomographic image data obtained in the main measurement can be displayed together with the correlation value.

  Moreover, it is possible to display any one of the four correlation values corresponding to the reference sections A to D. For example, all four correlation values can be displayed, or only the correlation values selected from these can be displayed. As an example of the latter, the minimum correlation value of the four correlation values can be selectively displayed. Further, only correlation values having a correlation value equal to or lower than a predetermined value (for example, the above threshold value) may be displayed.

  Further, when there is a correlation value equal to or smaller than a predetermined value, predetermined warning information may be displayed. Examples of the warning information include a message indicating that the positional deviation of the ultrasonic probe 2 is large, a message indicating that a suitable image has not been acquired, and a message prompting remeasurement.

[Second operation example]
A second operation example of the ultrasonic diagnostic apparatus 1 will be described with reference to the flowchart shown in FIG.

  First, similarly to the first operation example, reference tomographic image data of the heart in each reference section A to D is acquired for one heartbeat (S11).

  When the main measurement is started (S12), the scan control unit 81 starts transmission / reception of ultrasonic waves and rotation of the transducer unit 2a (S13). Thereby, tomographic image data of a plurality of cross sections including the reference cross sections A to D are sequentially generated (S14).

  Each time each of the reference sections A to D is scanned, that is, every time tomographic image data of the reference section is generated, the time phase specifying unit 82 specifies the time phase of the heart when the reference section is scanned. (S15), the data selection unit 83 selects reference tomographic image data corresponding to the specified time phase (S16).

  Further, the correlation calculation unit 84 calculates a correlation value between the tomographic image data of the reference cross section obtained in the main measurement and the selected reference tomographic image data (S17). The correlation determination unit 85 determines whether this correlation value is equal to or less than a threshold value (S18). Here, correlation value calculation results and determination results can be displayed.

  When it is determined that the correlation value is equal to or less than the threshold value during the scan to the predetermined scan end position (position where the transducer unit 2a is rotated 180 degrees from the scan start position) (S18: Yes), the scan control unit 81 controls the transmission / reception unit 3 and the moving mechanism 2b to scan the reference sections A to D again. Thereby, new reference tomographic image data in each reference section A to D is generated (S19).

  Subsequently, the scan control unit 81 controls the moving mechanism 2b to return the ultrasonic scan position to the cross section immediately before the reference cross section immediately before the reference cross section corresponding to the correlation value calculated in Step 17 (S20). ). Then, the scan control unit 81 resumes scanning from the scan position. Thereby, generation of tomographic image data of a plurality of cross sections is resumed (S21).

  Here, an example of processing in steps 20 and 21 will be described with reference to FIG. It is assumed that the correlation value in the reference cross section D is determined to be equal to or less than the threshold value. Since the determination process is performed after the scanning of the reference cross section D, the determination result is obtained when the cross-sectional positions after the reference cross section D are scanned. Here, it is assumed that the determination result is obtained when the scan position H is between the reference section D and the reference section A as shown in FIG.

  In response to this determination result, the scan control unit 81 returns the scan position H to the cross-sectional position (restart position) immediately before the reference cross section C immediately before the reference cross section D, as shown in FIG. At this time, the scan position H may be moved to the restart position along the direction shown in FIG. 7, that is, the rotation direction of the scan position H so far, or the scan position H may be rotated in the opposite direction. It may be moved to the resume position.

  Note that the fact that the correlation value is equal to or less than the threshold value in the reference cross section D means that the positional displacement of the ultrasonic probe 2 has occurred between the reference cross section C and the reference cross section D. Therefore, it is desirable to return to at least the reference section C and resume scanning. In addition, a region (overlapping region) between the reference cross section C and the restart position can be used as a “margin” when a plurality of three-dimensional image data is pasted (described later). Furthermore, it is desirable to set the restart position so that the rotational speed of the transducer portion 2a is constant before the reference cross section C after the scan is restarted. That is, the restart position can be determined in consideration of the accuracy of pasting of the three-dimensional image data, the torque applied by the moving mechanism 2b to the vibrator portion 2a, and the like.

  On the other hand, when it is not determined that the correlation value is equal to or less than the threshold value (S18: No), that is, when it is determined that the correlation value exceeds the threshold value, the process proceeds to step 22 without passing through steps 19 to 21.

  The scan control unit 81 determines whether scanning of the examination target region (for example, ROI) of the subject is completed (S22). This process can be performed, for example, by determining whether or not the vibrator unit 2a has been rotated once (that is, rotated 180 degrees) without being determined as “Yes” in Step 18.

  When the scan is resumed (S21) and it is determined that the scan has not ended (S22: No), the tomographic image data (new tomographic image data) for a plurality of cross sections including the new reference cross section are sequentially obtained. (S14), the time phase of the heart when a new reference section is scanned is specified (S15), new reference tomographic image data corresponding to the specified time phase is selected (S16), and the reference A correlation value between the new tomographic image data of the cross section and the new reference tomographic image data is calculated (S17). Thereafter, the processing of steps 18 to 22 is executed in the same manner as described above. The plurality of tomographic image data generated in this way is stored in the image storage unit 7.

  On the other hand, if it is determined that the correlation value exceeds the threshold value (S18: No), and it is determined that the scan has not been completed (S22: No), until “Yes” is determined in step 22, that is, inspection Steps 14 to 22 are executed in the same manner as described above until the scanning of the target area is completed. The plurality of tomographic image data generated in this way is stored in the image storage unit 7.

  When the scan of the inspection target region is completed (S22: Yes), the image generation unit 6 reads the generated plurality of tomographic image data and generates three-dimensional partial image data (S23). The three-dimensional partial image data is generated based on the tomographic image data group included in the corresponding region of the three-dimensional partial image data, as in the conventional volume data generation process.

  The three-dimensional partial image data is image data representing the form and function of at least a part (or the whole) of the inspection target region. If it is determined “Yes” at least once in Step 18, the number of three-dimensional partial image data obtained by adding 1 to the number of times determined “Yes” is generated. These three-dimensional partial image data are image data representing the form of different portions (partially overlapping: the overlapping region) of the inspection target region. On the other hand, if it is not determined as “Yes” at step 18, one three-dimensional image data representing the entire inspection target region is generated. The three-dimensional (partial) image data generated in this way is stored in the image storage unit 7.

  If it is determined at least once as “Yes” in step 18, the 3D image data synthesis unit 13 reads a plurality of three-dimensional partial image data from the image storage unit 7, and synthesizes them to obtain a 3D image of the entire inspection target region. Image data is generated (S24). This combining process is executed, for example, by pasting adjacent three-dimensional partial image data so that the correlation value of the image data in the overlapping region is maximized. If it is not determined “Yes” at step 18, step 24 need not be executed.

  The image generation unit 6 renders 3D image data (volume data) of the entire inspection target region, and generates 3D image data for display. The display control unit 86 displays an image based on the three-dimensional image data on the display unit 10 (S25).

  Here, an example of processing in the case where it is determined “Yes” at least once in Step 18 will be described. In this case, a tomographic image data group is obtained for each of the plurality of partial areas of the examination target area. Each tomographic image data group includes a plurality of tomographic image data in a region sandwiched between a reference cross section whose correlation value is determined to be equal to or less than a threshold and a cross section immediately before the previous reference cross section. The image generation unit 6 generates three-dimensional partial image data for each partial region based on the tomographic image data group. The 3D image data synthesizing unit 13 combines the plurality of three-dimensional partial image data to generate three-dimensional image data of the entire inspection target area.

  As an example, the case shown in FIG. 7 will be described. Here, it is assumed that “Yes” is determined only in the reference section D. In this case, the tomographic image data group (first tomographic image data group) in the region sandwiched between the reference cross section A and the reference cross section C, the cross section position immediately before the reference cross section C (the above restart position), and the reference cross section D A tomographic image data group (second tomographic image data group) in the region sandwiched between the two is obtained. Here, the region sandwiched between the restart position and the reference cross section C corresponds to the overlapping region.

  The image generation unit 6 generates three-dimensional partial image data (first three-dimensional image data) based on the first tomographic image data group, and three-dimensional partial image data (first three-dimensional image data) (based on the second tomographic image data group). Second 3D image data) is generated. The 3D image data composition unit 13 calculates a correlation value while changing the positional relationship between the image data of the overlapping region of the first three-dimensional image data and the image data of the overlapping region of the second three-dimensional image data. The positional relationship that maximizes the value is determined. Then, the 3D image data synthesis unit 13 synthesizes the first three-dimensional image data and the second three-dimensional image data so that the image data of each overlapping region are pasted together with the determined positional relationship. Thereby, three-dimensional image data of the entire inspection target region is generated.

  In the above processing, the positional relationship of the image data in the overlapping area may be determined so that the correlation value is equal to or greater than a predetermined value. Further, the positional relationship can be determined by calculating the correlation value for the designated image region. For example, only the outline portion of the heart (image region corresponding to the heart wall) in the overlapping region can be designated as the correlation value calculation target region. Further, one or more predetermined-shaped areas (for example, rectangular areas) may be designated.

  Conversely, an image area that is not desired to be included in the correlation value calculation target may be specified, and the correlation value may be calculated by excluding the specified area from the overlapping area. Examples of the exclusion target include an image region corresponding to a heart valve having a large movement. Further, one or more regions having a predetermined shape (for example, rectangular regions) may be designated as exclusion targets.

  The designation of the image area may be performed manually by the operator, or may be performed automatically by analyzing the image data. In the former case, for example, an image based on a tomographic image data group or three-dimensional partial image data can be displayed on the display unit 10, and a desired area in the display image can be designated using the operation unit 11.

  In the first operation example and the second operation example described above, particularly when obtaining reference tomographic image data, abnormal pulsation is detected, and when an abnormality is detected, the reference tomographic image data is re-acquired. Is possible. Abnormal pulsation is detected by the abnormality detector 87. Accordingly, by using the reference tomographic image data in an abnormal state, it is possible to improve the accuracy and accuracy of the generation processing and synthesis processing of the three-dimensional image data, and further improve the accuracy and accuracy of the image diagnosis. Can be planned.

[Action / Effect]
The operation and effect of the ultrasonic diagnostic apparatus 1 according to this embodiment will be described.

  The ultrasound diagnostic apparatus 1 generates a plurality of temporal tomographic reference tomographic image data in a reference cross section of the internal body part while referring to the periodically changing state of the internal body part. And the time phase are stored in association with each other. Furthermore, the ultrasonic diagnostic apparatus 1 sequentially generates tomographic image data in a plurality of cross sections including the reference cross section. At this time, the ultrasonic diagnostic apparatus 1 specifies the time phase of the internal body part when the reference cross section is ultrasonically scanned based on the fluctuation state of the internal body part, and the reference tomographic image data corresponding to the specified time phase Is selected from a plurality of stored reference tomographic image data. Then, the ultrasonic diagnostic apparatus 1 calculates a correlation value between the tomographic image data of the reference cross section and the selected reference tomographic image data, and presents information on the positional deviation of the ultrasonic probe 2 based on the correlation value.

  According to the ultrasonic diagnostic apparatus 1 that operates in this way, the correlation value of the image data in the reference cross section can be sequentially obtained and information on the positional deviation of the ultrasonic probe 2 can be presented, so that the ultrasonic probe 2 during the ultrasonic scan can be presented. Can be easily detected. Thus, by sequentially presenting objective information regarding the positional deviation of the ultrasonic probe 2, it is possible to avoid a situation in which an inspection is performed in a state where the positional deviation of the ultrasonic probe 2 has occurred. It is possible to improve accuracy.

  Further, the ultrasonic diagnostic apparatus 1 determines whether or not the calculated correlation value is equal to or less than a threshold value, and if it is determined that the calculated correlation value is equal to or less than the threshold value, generates the new reference tomographic image data in the reference cross section. Acts as follows. As a result, even if the ultrasonic probe 2 is displaced, the inspection can be performed smoothly.

  In addition, the ultrasonic diagnostic apparatus 1 generates reference tomographic image data of each time phase in each reference cross section. Further, when the ultrasonic diagnostic apparatus 1 sequentially generates tomographic image data of a plurality of cross sections, it identifies the time phase when each reference cross section is scanned and selects the reference tomographic image data for each reference cross section. Then, a correlation value for each reference cross section is calculated. Then, when it is determined that the correlation value is equal to or less than the threshold, the ultrasound diagnostic apparatus 1 generates new reference tomographic image data in each reference section, and further, one of the reference sections corresponding to the correlation value. The scan position is returned to the cross section immediately before the previous reference cross section, and the generation of tomographic image data of a plurality of cross sections is resumed. As a result, the inspection can be smoothly resumed even when the position of the ultrasonic probe 2 is displaced.

  Further, when the correlation value is determined to be equal to or less than the threshold value, the ultrasound diagnostic apparatus 1 uses the first three-dimensional image data based on the tomographic image data group in the region sandwiched between the reference cross section and the immediately previous cross section. And the second three-dimensional image data is generated based on the tomographic image data group in the region sandwiched between the previous reference cross section and the previous reference cross section. Further, the ultrasonic diagnostic apparatus 1 uses the first three-dimensional image data so that the correlation value of the image data in the region (overlapping region) between the previous reference cross section and the immediately previous cross section is maximized. And the second three-dimensional image data are synthesized. Thereby, three-dimensional image data of the entire inspection target region is generated. According to such an ultrasonic diagnostic apparatus 1, it is possible to align adjacent three-dimensional image data with high accuracy and high accuracy, and it is possible to improve the accuracy and accuracy of image diagnosis.

It is a block diagram showing an example of schematic structure of an embodiment of an ultrasonic diagnostic equipment concerning this invention. It is a block diagram showing an example of schematic structure of an embodiment of an ultrasonic diagnostic equipment concerning this invention. It is a flowchart showing an example of operation | movement of embodiment of the ultrasonic diagnosing device based on this invention. It is the schematic showing an example of the reference section in the embodiment of the ultrasonic diagnostic equipment concerning this invention. It is the schematic showing an example of the memory | storage aspect of the reference | standard tomographic image data in embodiment of the ultrasonic diagnosing device which concerns on this invention. It is a flowchart showing an example of operation | movement of embodiment of the ultrasonic diagnosing device based on this invention. It is the schematic for demonstrating an example of operation | movement of embodiment of the ultrasonic diagnosing device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 2 Ultrasonic probe 2a Transducer part 2b Movement mechanism 3 Transmission / reception part 4 Signal processing part 5 Data storage part 6 Image generation part 7 Image storage part 8 Control part 81 Scan control part 82 Time phase specific part 83 Data selection Unit 84 correlation calculation unit 85 correlation determination unit 86 display control unit 87 abnormality detection unit 9 user interface 10 display unit 11 operation unit 12 image processing unit 13 3D image data synthesis unit 20 electrocardiograph

Claims (6)

A detecting means for detecting a fluctuation state of a body part that periodically changes;
Generating means for generating tomographic image data based on the scan result, including an ultrasound probe that scans the internal body part with ultrasound;
Control means for causing the generation means to generate reference tomographic image data for each of a plurality of time phases included in one cycle of the fluctuation in a predetermined reference cross section of the internal body part while referring to the detected fluctuation state; ,
Storage means for storing the generated reference tomographic image data and time phases in association with each other;
When the tomographic image data in a plurality of cross sections including the predetermined reference cross section is sequentially generated by the generating means, the predetermined reference cross section is the ultrasonic wave based on the fluctuation state detected by the detecting means. A specifying means for specifying a time phase of the internal part when scanned;
Selecting means for selecting reference tomographic image data corresponding to the specified time phase from the plurality of stored reference tomographic image data;
A computing means for computing a correlation value between the tomographic image data of the predetermined reference slice of the plurality of slices and the selected reference tomographic image data;
Presenting means for presenting information on positional deviation of the ultrasonic probe based on the calculated correlation value;
An ultrasonic diagnostic apparatus comprising: The control means determines whether or not the calculated correlation value is less than or equal to a threshold value. When it is determined that the calculated correlation value is less than or equal to the threshold value, the control means controls the generation means to generate a new reference cross section. Generating the reference tomographic image data;
The ultrasonic diagnostic apparatus according to claim 1. The predetermined reference cross section includes a plurality of reference cross sections;
The control means causes the generation means to generate reference tomographic image data of each of the plurality of time phases in each reference cross section,
When the tomographic image data of the plurality of cross-sections are sequentially generated by the generating unit, the specifying unit is used when the reference cross-section is scanned each time the reference cross-section is scanned with the ultrasound. Phase is specified, the selection means selects the reference tomographic image data for the reference cross section, the calculation means calculates the correlation value for the reference cross section, and the control means has the correlation value equal to or less than the threshold value. To determine whether
When it is determined that the correlation value is equal to or less than the threshold value, the control unit controls the generation unit to generate the new reference tomographic image data in each reference section, and further corresponds to the correlation value Returning the scan position of the ultrasonic wave to the cross section immediately before the reference cross section immediately before the reference cross section to be generated, and restarting the generation of the tomographic image data of the plurality of cross sections.
The ultrasonic diagnostic apparatus according to claim 2. The generation unit generates first three-dimensional image data based on a tomographic image data group in a region sandwiched between the reference cross section and the immediately previous cross section when the control unit determines that the threshold value is less than or equal to the threshold value. And generating second 3D image data based on a tomographic image data group in a region sandwiched between the previous reference slice and the previous reference slice,
Combining means for synthesizing the first three-dimensional image data and the second three-dimensional image data so that the correlation value of the image data between the previous reference cross section and the previous cross section is maximized. Comprising
The ultrasonic diagnostic apparatus according to claim 3. The control unit detects an abnormality of the variation based on a variation state detected by the detection unit, and controls the generation unit when the abnormality is detected, thereby generating a new one in the predetermined reference cross section. Generating the reference tomographic image data;
The ultrasonic diagnostic apparatus according to claim 1. The ultrasonic probe includes a plurality of ultrasonic transducers, and a moving mechanism that moves the plurality of ultrasonic transducers and changes a scan position by the ultrasonic waves,
The predetermined reference cross section is determined by positions of the plurality of ultrasonic transducers to be moved.
The ultrasonic diagnostic apparatus according to any one of claims 1 to 5, wherein:

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