JP5999935B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus for diagnosing plaque attached to a blood vessel wall.

  In lesions such as arteriosclerosis, plaque adhered to the blood vessel wall is observed, and an ultrasonic diagnostic apparatus is used to diagnose the state of the plaque. For example, Patent Document 1 describes an epoch-making invention that clearly displays a floating piece (jellyfish sign) in which the surface of the plaque rises and falls due to the pulsation of blood flow in an unstable plaque. Yes.

  By the way, in the living body, the blood vessel is moved by pulsation, and the plaque adhering to the blood vessel wall also moves together with the blood vessel. Therefore, when detecting the floating piece in the plaque, the movement of the blood vessel due to pulsation and the movement of the floating piece in the plaque overlap, and the detection of the floating piece becomes poor. When detecting the floating piece in the plaque, the fact that the plaque does not move as a whole leads to an improvement in detection.

  Further, in order to detect a movable part such as a floating piece in the plaque, it is desirable that the state of movement in a plurality of parts in the plaque can be detected easily and accurately.

JP 2011-98016 A

  The present invention has been made in view of the background art described above, and an object thereof is to provide an improved technique related to an ultrasonic diagnostic apparatus for diagnosing plaque adhered to a blood vessel wall.

  A suitable ultrasonic diagnostic apparatus for the above purpose includes a probe for transmitting and receiving an ultrasonic wave for a diagnostic region including plaque attached to a blood vessel wall, and transmission and reception for obtaining an ultrasonic reception signal from the diagnostic region by controlling the probe. A reference for setting an analysis reference region for each of a plurality of plaque sites with reference to a display reference region set for the entire plaque in the image data relating to the diagnosis region obtained based on the received signal An area setting unit, and an image forming unit that forms a display image indicating the amount of movement of each part of the plaque obtained using the analysis reference region while adjusting the display position of the plaque using the display reference region It is characterized by having.

  In the above apparatus, a preferable specific example of the image relating to the diagnostic region is a tomographic image in a blood vessel to which plaque is attached. For the display reference area, for example, a user who has visually recognized the image of the diagnosis area may determine the position, size, and shape of the display reference area in the image, or the apparatus identifies the plaque in the image, and the identification result The position, size, shape, etc. of the display reference area may be determined according to the above. As for the analysis reference area, for example, although it is desirable to set a plurality of analysis reference areas in the display reference area, the analysis reference area may be set at a point of interest outside the display reference area. Further, even within the display reference area, the analysis reference area may be omitted at a location that does not particularly require attention.

  According to the above apparatus, an improved technique for diagnosing plaque attached to a blood vessel wall is provided. For example, since the analysis reference area is set for each of a plurality of plaque parts based on the display reference area set for the whole plaque, the analysis reference area suitable for diagnosis is set relatively easily. can do. In addition, a display image showing the amount of movement of each part of the plaque obtained using the analysis reference area is formed while adjusting the display position of the plaque using the display reference area. It becomes relatively easy to confirm the state of movement at the site, and the state of movement can be diagnosed with relatively high accuracy.

  In a preferred embodiment, the reference area setting unit sets a display reference area so as to surround the plaque as a whole in the image data, and divides the display reference area into a plurality of partial areas. Is set in the analysis reference area.

  In a preferred embodiment, the ultrasonic diagnostic apparatus includes a tracking processing unit that tracks the position of the display reference region over a plurality of time phases in the image data by pattern matching processing using the display reference region as a template, And a movement amount calculation unit that calculates a movement amount of a portion corresponding to each analysis reference region in the image data by a pattern matching process using an analysis reference region as a template. The unit forms a display image indicating the amount of movement corresponding to each of the plurality of plaque portions while fixing the overall display position of the plaque over a plurality of time phases based on the position of the tracked display reference region. It is characterized by.

  In a desirable specific example, the movement amount calculation unit calculates a vector amount of movement between time phases of the corresponding parts for each analysis reference region, and the image forming unit performs movement corresponding to each of the plurality of plaque parts. A display image in which the vector amount is indicated by an arrow is formed.

  In addition, a suitable program that meets the above-described purpose is a plurality of plaque sites on the basis of a display reference region that is set for the entire plaque in the ultrasound image data regarding the diagnostic region including the plaque attached to the blood vessel wall. A reference area setting function for setting an analysis reference area for each of the above and a movement amount of each part of the plaque obtained by using the analysis reference area while adjusting the display position of the plaque using the display reference area An image forming function for forming a display image showing the above is realized in a computer.

  The program is stored in a computer-readable storage medium such as a disk or a memory, and is provided to the computer via the storage medium. Of course, the program may be provided to the computer via a telecommunication line such as the Internet.

  According to the present invention, an improved technique related to an ultrasonic diagnostic apparatus for diagnosing plaque adhered to a blood vessel wall is provided. For example, according to a preferred aspect of the present invention, an analysis reference region suitable for diagnosis can be set relatively easily. Further, it becomes relatively easy to confirm the state of movement at a plurality of sites in the plaque, and the state of movement can be diagnosed with relatively high accuracy.

1 is an overall configuration diagram of an ultrasonic diagnostic apparatus suitable for implementing the present invention. It is a figure which shows the specific example of a display reference area and a display image. It is a figure which shows the specific example of an analysis reference area. It is a figure which shows the specific example of the display image which showed the movement amount of each site | part of a plaque.

  FIG. 1 is an overall configuration diagram of an ultrasonic diagnostic apparatus (present ultrasonic diagnostic apparatus) suitable for implementing the present invention. The probe 10 transmits an ultrasonic wave to a diagnostic region including a plaque attached to a blood vessel wall such as a carotid artery, and receives an ultrasonic wave reflected from the diagnostic region. The probe 10 includes a plurality of vibration elements that transmit and receive ultrasonic waves, and transmission of the plurality of vibration elements is controlled by the transmission / reception unit 12 to form a transmission beam. Further, the plurality of vibration elements receive the ultrasonic waves reflected from the diagnostic region, and signals obtained thereby are output to the transmission / reception unit 12, and the transmission / reception unit 12 forms a reception beam.

  The transmission / reception unit 12 outputs a transmission signal corresponding to each of the plurality of vibration elements included in the probe 10, thereby forming an ultrasonic transmission beam and scanning the transmission beam. Further, the transmission / reception unit 12 forms a reception beam corresponding to the transmission beam to be scanned by performing a phasing addition process or the like on the reception signal obtained from each of the plurality of vibration elements included in the probe 10, and receives the reception beam. Echo data (received signal) obtained along the beam is output.

  The image data storage unit 20 stores echo data (received signal) obtained over a plurality of time phases. That is, the image data storage unit 20 includes, for example, image data related to a tomographic image (B-mode image) in a blood vessel in which plaque adheres to the blood vessel wall over a plurality of frames for each frame (for each time phase). Remembered.

  The tomographic image data stored in the image data storage unit 20 is output to the reference area setting unit 30 one after another for each frame. The image data stored in the image data storage unit 20 is output to the image forming unit 70 one after another for each frame, and the image forming unit 70 forms a tomographic image corresponding to the image data. It is displayed on a display unit 80 such as a monitor.

  The reference area setting unit 30 sets a reference area in the image data of the tomographic image. The reference area setting unit 30 first sets a display reference area for the entire plaque. For example, the reference area setting unit 30 sets the display reference area in accordance with a user operation input via the operation device 40. For example, the user operates the operation device 40 so that the display reference region is set at a desired position while viewing the tomographic image displayed on the display unit 80. Note that the reference region setting unit 30 may analyze the image state in the tomographic image, recognize the plaque image portion having a relatively high luminance, and set the display reference region for the entire plaque.

  When the display reference area is set, the tracking processing unit 50 tracks (tracks) the position of the display reference area over a plurality of time phases in the image data by pattern matching processing using the display reference area as a template. Then, the image forming unit 70 fixes the overall display position of the plaque over a plurality of time phases based on the position of the tracked display reference area, and displays a moving image display image based on the tomographic images over the plurality of time phases. Then, the display image of the moving image is displayed on the display unit 80.

  FIG. 2 is a diagram illustrating a specific example of a display reference area and a display image. FIG. 2 (1) shows image data and a display image in frame 1 corresponding to one of a plurality of time phases. FIG. 2 (2) shows a time phase after frame 1 (for example, frame 1). The image data and the display image in the frame 2 corresponding to the time phase immediately after) are shown.

  In FIG. 2, the image data area corresponds to the entire scanning area where the ultrasonic beam is scanned and echo data is collected, and the image data in this image data area is the image data storage unit 20 (FIG. 1). Is remembered. The image data includes an image portion of the blood vessel wall V and an image portion of the plaque P attached to the blood vessel wall V.

  In the living body, the blood vessel moves due to pulsation or the like, and therefore the plaque P also moves with the blood vessel wall V as a whole. Therefore, for example, in a state where the probe 10 (FIG. 1) is fixed to the body surface of the subject, echo data is collected over a plurality of time phases from within the diagnostic region including the blood vessel, and the plurality of frames are covered. When a moving image of a tomographic image is obtained, the plaque P moves as a whole together with the blood vessel wall V in the moving image. Therefore, for example, as illustrated in FIG. 2, the blood vessel wall V and the plaque P attached thereto move from the position of the frame 1 to the position of the frame 2 in the image data.

  Therefore, in the present ultrasonic diagnostic apparatus, the display reference area 32 is used to cope with the overall movement of the plaque P. The reference area setting unit 30 (FIG. 1) sets the display reference area 32 in the image data corresponding to a certain time phase, for example, the image data of frame 1 shown in FIG. The display reference area 32 is set so as to surround the plaque P to be diagnosed as a whole, for example. 2 shows a rectangular display reference area 32, the display reference area 32 may have another polygonal shape, a circular shape, an elliptical shape, or the like.

  When the display reference area 32 is set, the tracking processing unit 50 (FIG. 1) determines the position of the display reference area 32 over a plurality of time phases in the image data by pattern matching processing using the display reference area 32 as a template. To track. For example, when the display reference area 32 is set in the image data of frame 1 shown in FIG. 2A, the tracking processing unit 50 is most similar to the image data in the display reference area 32 of frame 1 (pattern). Search for the image portion in the frame 2 image data. Thereby, for example, as shown in FIG. 2B, the position of the display reference area 32 is specified in the image data of the frame 2. Tracking of the position of the display reference area 32 is continued over a plurality of frames even after the frame 2.

  In tracking over a plurality of frames, the image data at the initial position (frame 1) of the display reference area 32 may continue to be used as a template, and each time the movement position of the display reference area 32 is specified, The image data at the position of the display reference area 32 in the specified frame may be updated to a new template. When searching for an image portion corresponding to the display reference area 32 in the image data, the entire area within the frame to be searched (the entire area of the image data area) may be searched, or the frame to be searched for The search area may be set in accordance with the position of the display reference area 32 before the movement, and the search may be performed within the search area.

  When the display reference area 32 is tracked over a plurality of time phases, the image forming unit 70 (FIG. 1) performs the entire plaque P over a plurality of time phases based on the position of the tracked display reference area 32. A tomographic image over a plurality of time phases is formed while fixing a display position. For example, as shown in FIG. 2A, the image data in the display area including the display reference area 32 is extracted from the image data of frame 1, and the display image of frame 1 is extracted from the image data in the display area. Is formed. Similarly, as shown in FIG. 2 (2), the image data in the display area including the display reference area 32 is extracted from the image data of frame 2, and the display of frame 2 is performed from the image data in the display area. An image is formed. At that time, the position of the display reference area 32 in the display area is fixed over a plurality of frames.

  Thereby, as illustrated in FIG. 2, the position of the display reference area 32 is fixed in the display images of the frames 1 and 2, and the overall display position of the plaque P is also fixed. Although the overall display position of the plaque P is fixed, partial movements in each part of the plaque P are reflected in the moving image.

  Returning to FIG. 1, the reference area setting unit 30 further sets an analysis reference area for each of a plurality of parts of the plaque based on the display reference area. When the analysis reference area is set, the movement amount calculation unit 60 calculates the movement amount between the phases corresponding to each analysis reference area in the image data by pattern matching processing using the analysis reference area as a template. To do. Then, the image forming unit 70 fixed the plaque display position using the display reference area as described above, and further showed the movement amount of each part of the plaque obtained using the analysis reference area. A display image is formed.

  FIG. 3 is a diagram showing a specific example of the analysis reference region. FIG. 3 shows an image portion of the blood vessel wall V and an image portion of the plaque P attached to the blood vessel wall V in the image data. As described with reference to FIG. 2, the display reference area 32 is set so as to surround the plaque P to be diagnosed as a whole. The reference area setting unit 30 (FIG. 1) sets a plurality of analysis reference areas 34 for the plaque P based on the set display reference area 32.

  For example, as shown in FIG. 3, the display reference area 32 is divided into a plurality of partial areas, and the plurality of partial areas are set as a plurality of analysis reference areas 34. In FIG. 3, a gap is provided between the analysis reference areas 34 adjacent to each other, but the analysis reference area 34 may be set without providing a gap. Further, a gap may be provided between the display reference area 32 and the analysis reference area 34 or there may be no gap. In addition, the analysis reference area 34 may be set at a point of interest outside the display reference area 32, or even within the display reference area 32, the analysis reference area 34 may be omitted at a place where no particular attention is required. It may be. Also. Although the rectangular analysis reference area 34 is shown in FIG. 3, the shape of the analysis reference area 34 may be another polygon, a circle, an ellipse, or the like.

  When the analysis reference area 34 is set, the movement amount calculation unit 60 (FIG. 1) performs a pattern matching process using the analysis reference area 34 as a template for each analysis reference area 34 corresponding to the analysis reference area 34. The amount of movement between time phases is calculated.

  For example, when the analysis reference area 34 is set in the image data of frame 1, the movement amount calculation unit 60 is the image portion most similar to the image data in the analysis reference area 34 of frame 1 (the pattern matches). In the image data of frame 2. Thereby, the movement position of the analysis reference area 34 is specified in the image data of the frame 2 for each analysis reference area 34. Then, for each analysis reference region 34, the movement distance in the x-axis direction (horizontal direction) and the y-axis direction (vertical direction) is calculated. That is, the movement amount of the part corresponding to the analysis reference area 34 is calculated as a two-dimensional vector amount in the x-axis direction and the y-axis direction. Note that the movement amount may be calculated between adjacent frames, or may be calculated between frames separated by the number of frames specified by the user, for example.

  In this way, when the movement amount is calculated between frames, the movement amount is calculated one after another even after the next frame. When calculating the movement amount one after another, the analysis reference area 34 is also updated according to the display reference area 32 specified in the frame that is the starting point before the movement. For example, when the movement amount is calculated between the frame 1 and the frame 2 shown in FIG. 2, a plurality of analysis reference areas 34 are set based on the display reference area 32 of the frame 1, and the image data in the frame 2 Thus, the movement destination of each analysis reference area 34 is searched. Subsequently, for example, when the movement amount is calculated between the frame 2 shown in FIG. 2 and the frame 3 (not shown), a plurality of analysis reference areas 34 are set based on the display reference area 32 specified in the frame 2. Then, the movement destination of each analysis reference area 34 is searched in the image data of frame 3 (not shown).

  The movement amount of the analysis reference area 34 may include a movement amount component of the display reference area 32, that is, an overall movement amount component of the plaque P, or based on the movement amount of the display reference area 32. Alternatively, the movement amount of the analysis reference area 34 may be calculated by subtracting the overall movement amount component of the plaque P.

  When the movement amount for each of the plurality of analysis reference areas 34 is calculated, the image forming unit 70 (FIG. 1) further fixes the display position of the plaque P as described with reference to FIG. A display image showing the amount of movement of each part of the plaque P obtained using the analysis reference area 34 is formed.

  FIG. 4 is a diagram showing a specific example of a display image showing the amount of movement of each part of the plaque. The image forming unit 70 (FIG. 1) forms the display image shown in FIG. 4 by indicating the movement amount of each analysis reference region 34, that is, the two-dimensional vector amount, by an arrow. In FIG. 4, a plurality of arrows superimposed on the plaque P and the blood vessel wall V correspond to the movement amounts of the plurality of analysis reference regions 34 shown in FIG. For example, the direction and length of the arrow for the analysis reference area 34 are set according to the movement amount in the x-axis direction and the movement amount in the y-axis direction calculated for each analysis reference area 34. That is, the direction of movement is indicated by the direction of the arrow, and the magnitude of movement (movement distance) is indicated by the length of the arrow. The starting point of each arrow is, for example, the center of the analysis reference area 34 corresponding to the arrow. When the luminance of the pixel at the center of the analysis reference area 34 is smaller than the threshold value, it may be determined that the pixel is not the plaque P and the arrow may not be displayed.

  In addition, when a plurality of arrows are shown, the display mode of the arrows may be varied depending on the direction of the arrows. For example, an arrow having an x-axis positive direction (right direction) component and an x-axis negative direction (left direction) component in image data are displayed separately from each other by different colors. Also good. As a result, as illustrated in FIG. 4, the arrow A having a component in a direction different from the others is easily identified by, for example, a difference in color, and the movement of the plaque P is unique at the portion indicated by the arrow A. Is clearly shown. In addition, each portion of the plaque P may be colored according to the direction of movement, and the arrow display may be omitted.

  The ultrasonic diagnostic apparatus according to the preferred embodiment of the present invention has been described above. For example, the ultrasonic diagnostic apparatus is illustrated in FIG. 1 by a program corresponding to some or all of the processes described in detail with reference to FIGS. A part or all of the functions of the image data storage unit 20, the reference region setting unit 30, the tracking processing unit 50, the movement amount calculating unit 60, and the image forming unit 70 are realized by a computer, and the computer is used as an ultrasonic image processing apparatus. May function.

  The above-described embodiments are merely examples in all respects, and do not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

  DESCRIPTION OF SYMBOLS 10 probe, 12 transmission / reception part, 20 image data memory | storage part, 30 reference area setting part, 50 tracking process part, 60 movement amount calculating part, 70 image formation part, 80 display part.

Claims (5)

A probe for transmitting and receiving ultrasound for a diagnostic region including plaque attached to a blood vessel wall;
A transmission / reception unit that obtains an ultrasonic reception signal from the diagnostic region by controlling the probe; and
A reference region setting unit that sets an analysis reference region for each of a plurality of plaque sites with reference to a display reference region that is set for the entire plaque in image data related to a diagnostic region obtained based on a received signal When,
A tracking processing unit that tracks the position of the display reference region over a plurality of time phases in the image data by pattern matching processing using the display reference region as a template;
By a pattern matching process using the analysis reference area as a template, a movement amount calculation unit that calculates a movement amount between portions corresponding to each analysis reference area in the image data,
While adjusting the display position of the plaque by using the display reference area, and an image forming unit for forming a display image showing the amount of movement of each part of the plaques obtained by using the analysis reference area,
I have a,
In calculating the movement amount between the time phases of the previous time phase and the later time phase over a plurality of time phases, the analysis reference region is based on the display reference region set in the image data corresponding to the previous time phase. In the image data corresponding to the later time phase, search for the movement destination of the part corresponding to each analysis reference area in the image data, to calculate the amount of movement between the time phases,
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The reference area setting unit sets a display reference area so as to entirely surround the plaque in the image data, divides the display reference area into a plurality of partial areas, and sets each partial area as an analysis reference area. Set,
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1 or 2 ,
The image forming unit fixes the overall display position of the plaque over a plurality of time phases based on the position of the tracked display reference area, and displays the movement amount corresponding to each of the plurality of plaque portions. Forming an image,
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3 ,
The movement amount calculation unit calculates a vector amount of movement between time phases of the corresponding parts for each analysis reference region,
When the image forming unit forms a display image in which the vector amount of movement corresponding to each of a plurality of parts of the plaque is indicated by an arrow, the luminance value of the pixel at the center of the analysis reference region corresponding to each part is a threshold value If it is smaller than, do not display the arrow corresponding to each part concerned,
An ultrasonic diagnostic apparatus. An analysis reference region is set for each of a plurality of plaque sites with reference to a display reference region set for the entire plaque in the ultrasound image data regarding the diagnostic region including the plaque attached to the blood vessel wall. Reference area setting function,
A tracking processing function for tracking the position of the display reference region over a plurality of time phases in the image data by pattern matching processing using the display reference region as a template;
By a pattern matching process using the analysis reference region as a template, in the image data, a movement amount calculation function for calculating a movement amount between portions corresponding to each of the analysis reference regions,
While adjusting the display position of the plaque by using the display reference area, and an image forming function for forming a display image showing the amount of movement of each part of the plaques obtained by using the analysis reference area,
In calculating the movement amount between the time phases of the previous time phase and the later time phase over a plurality of time phases, the analysis reference region is based on the display reference region set in the image data corresponding to the previous time phase. A function of searching for a movement destination corresponding to each analysis reference area in the image data corresponding to the later time phase, and calculating the movement amount between the time phases;
The computer
A program characterized by that.

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