JP2009039240A - Ultrasonic diagnostic apparatus and ultrasonic image processing program - Google Patents

Abstract

An ultrasonic diagnostic apparatus capable of generating an image representing the position of a moving body in a subject and the flow velocity of the moving body.
Volume data of a subject is acquired by transmitting ultrasonic waves to the subject with an ultrasonic probe and a transmission / reception unit. The extraction unit 61 extracts volume data representing the blood vessel form from the volume data. The observation point setting unit 91 sets observation points for each part of the blood vessel in the three-dimensional region. By performing Doppler scan on each observation point by the ultrasonic probe 2 and the transmission / reception unit 3, the blood flow velocity at each observation point is acquired. The color assigning unit 65 assigns a color corresponding to the blood flow velocity at each observation point to each part of the volume data representing the blood vessel form. The three-dimensional image generation unit 66 generates three-dimensional image data that represents a blood vessel three-dimensionally based on volume data to which a color is assigned.
[Selection] Figure 1

Description

  The present invention acquires an image representing a form in a subject by scanning the subject with ultrasound, and obtains a flow velocity of a moving body such as a blood flow flowing in the subject, and an ultrasound The present invention relates to an image processing program.

  The ultrasonic diagnostic apparatus can obtain the flow velocity of a moving body such as a blood flow flowing in the subject by performing Doppler scan. Conventionally, by using a power Doppler method (Power Angio), a three-dimensional image that three-dimensionally represents a blood flow in a subject is acquired, and the three-dimensional image is displayed. By observing a three-dimensional image obtained by using this power Doppler method, it is possible to grasp the travel of the blood vessel. Further, according to the power Doppler method, the angle dependency of ultrasonic waves to be transmitted and received can be reduced, and the color reversal and noise ratio of an image representing blood flow can be improved.

  Further, a technique for extracting blood vessel position information from volume data that three-dimensionally represents a tissue in a subject is known (for example, Patent Document 1). According to this, a three-dimensional image of the blood vessel in the region of interest can be drawn.

JP-A-8-131429

  However, with the power Doppler method, it is possible to grasp the running of the blood vessel, but it is difficult to obtain blood flow values in each part of the blood vessel with high accuracy. Therefore, it has been difficult to more accurately grasp the blood flow value in each part of the blood vessel.

  Further, when diagnosing the progress of a tumor or removing a tumor, it is required to accurately grasp information on blood vessels in the organ. For example, it is required to accurately grasp the position of blood vessels and blood flow velocity in an organ. Therefore, information that can be used for grasping the position of blood vessels and blood flow velocity in an organ is desired. Furthermore, for blood vessels, information that can accurately grasp the position where vascular stenosis has occurred is desired.

  The present invention solves the above problem, and an ultrasonic diagnostic apparatus capable of generating an image representing the position of a moving body in a subject and the flow velocity of the moving body, and ultrasonic image processing The purpose is to provide a program.

According to the first aspect of the present invention, image acquisition means for transmitting ultrasonic waves to the subject and acquiring volume data of the subject, and extracting volume data representing a blood vessel form from the volume data of the subject Extraction means for performing, observation point setting means for setting observation points along the blood vessel in the three-dimensional region based on the volume data representing the extracted blood vessel form, and each of the three-dimensional regions set in the three-dimensional region By transmitting an ultrasonic wave to the position indicated by the observation point and executing a Doppler scan, a flow velocity acquisition means for acquiring the flow velocity of the moving body at the location where the observation point of the blood vessel is set, and the acquired flow velocity By assigning a color corresponding to the size to the location where the observation point is set in the volume data representing the blood vessel morphology, a color volume assigned to each location is displayed. And coloring means for generating a Yumudeta, an ultrasonic diagnostic apparatus characterized by having a display control means for displaying on the display means an image based on the color volume data.
The invention according to claim 12 receives volume data of the subject acquired by transmitting ultrasonic waves to the subject to a computer, and represents a blood vessel form from the volume data of the subject. Volume data that represents the form of the blood vessel, with an extraction function that extracts volume data, and the flow velocity of the moving body acquired in each part of the blood vessel in the three-dimensional space, and a color corresponding to the magnitude of the flow velocity in each part By assigning to each part, a color arrangement function for generating color volume data in which a color is assigned to each part and a display control function for displaying an image based on the color volume data on a display device are executed. This is an ultrasonic image processing program.

  According to the present invention, by assigning a color corresponding to the flow velocity of the moving body (blood) to an image representing the shape of the blood vessel, the operator can determine the position of the blood vessel in the three-dimensional space and each part of the blood vessel. It is possible to clearly grasp the speed of the moving body (blood flow). As a result, the operator can clearly specify, for example, the position where the vascular stenosis has occurred based on the color assigned to the image.

(Constitution)
A configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

  An ultrasonic diagnostic apparatus 1 according to this embodiment includes an ultrasonic probe 2, a transmission / reception unit 3, a signal processing unit 4, a data storage unit 5, an image processing unit 6, a display control unit 7, a user interface (UI) 8, and a control. Part 9 is provided.

  As the ultrasonic probe 2, a two-dimensional array probe in which a plurality of ultrasonic transducers are two-dimensionally arranged is used. The two-dimensional array probe can scan a three-dimensional region by transmitting and receiving ultrasonic waves. The ultrasonic probe 2 may be a one-dimensional array probe in which a plurality of ultrasonic transducers are arranged in a line in a predetermined direction (scanning direction). Furthermore, as the ultrasonic probe 2, a one-dimensional array probe that can scan a three-dimensional region by mechanically swinging the ultrasonic transducer in a direction (swing direction) orthogonal to the scanning direction is used. May be.

  The transmission / reception unit 3 includes a transmission unit and a reception unit, supplies an electrical signal to the ultrasonic probe 2 to generate an ultrasonic wave, and receives an echo signal received by the ultrasonic probe 2.

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

  The receiving unit of the transmitting / receiving unit 3 includes a preamplifier circuit, an A / D conversion circuit, and a reception delay / adder circuit (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 / adder circuit gives a delay time necessary for determining the reception directivity to the echo signal after A / D conversion, and adds the delay time. By the addition, the reflection component from the direction according to the reception directivity is emphasized. The signal added by the transmission / reception unit 3 is referred to as “RF data”.

  The signal processing unit 4 includes a B-mode processing unit 41 and a Doppler processing unit 42.

  The B-mode processing unit 41 visualizes echo amplitude information and generates B-mode ultrasonic raster data from the echo signal. Specifically, the B-mode processing unit 41 performs band-pass filter processing on the signal sent from the transmission / reception unit 3, then detects the envelope of the output signal, and performs logarithmic conversion on the detected data. Apply compression processing.

  The Doppler processing unit 42 generates blood flow information by, for example, a pulse Doppler method (PW Doppler method). According to the pulse Doppler method, since a pulse wave is used, a Doppler shift frequency component at a specific depth can be detected. Thus, since it has distance resolution, it is possible to measure the velocity of tissue and blood flow at a specific site. The Doppler processing unit 42 extracts a Doppler shift frequency component by phase-detecting a received signal within an observation point (sample position) having a predetermined size with respect to the signal transmitted from the transmission / reception unit 3, and further performs FFT processing To generate a Doppler frequency distribution representing a blood flow velocity within an observation point (sample position) having a predetermined size.

  Further, the signal processing unit 4 may include a color mode processing unit. The color mode processing unit visualizes moving blood flow information and generates color ultrasonic raster data. Blood flow information includes information such as speed, dispersion, and power, and blood flow information is obtained as binarized information.

  The ultrasonic probe 2, the transmission / reception unit 3, and the signal processing unit 4 correspond to an example of the “image acquisition unit” of the present invention.

  The signal processing unit 4 outputs the ultrasonic raster data to the image processing unit 6. The signal processing unit 4 outputs the ultrasonic raster data to the data storage unit 5, and the data storage unit 5 stores the ultrasonic raster data. Further, when volume data is acquired by executing volume scanning by the ultrasonic probe 2 and the transmission / reception unit 3, the signal processing unit 4 outputs the volume data to the image processing unit 6. Further, the signal processing unit 4 outputs the volume data to the data storage unit 5, and the data storage unit 5 stores the volume data. That is, when volume data is acquired by scanning a three-dimensional area with the ultrasound probe 2 and the transmission / reception unit 3, volume data representing the three-dimensional area is stored in the data storage unit 5.

  In this embodiment, a case where a blood vessel of a subject is taken as an example of an imaging target and volume data including the blood vessel is acquired by performing a volume scan on the subject will be described.

  Next, the image processing unit 6 and the control unit 9 will be described. The image processing unit 6 includes an extraction unit 61, a color arrangement unit 62, and a three-dimensional image generation unit 66. The color arrangement unit 62 includes a color determination unit 63, an interpolation unit 64, and a color allocation unit 65. The control unit 9 includes an observation point setting unit 91 and an angle correction unit 92.

  The extraction unit 61 receives volume data from the signal processing unit 4 and extracts volume data representing a blood vessel form from the volume data. The extraction unit 61 may read volume data from the data storage unit 5 and extract volume data representing a blood vessel form from the volume data. The extraction unit 61 extracts volume data representing a blood vessel form by an extraction method according to the related art. For example, the extraction unit 61 extracts volume data representing the shape of a blood vessel based on the pixel value of each point constituting the volume data. Further, the extraction unit 61 may extract volume data representing a blood vessel form by using an extraction technique disclosed in Japanese Patent Laid-Open No. 8-131429.

  Here, volume data representing the morphology of blood vessels will be described with reference to FIG. FIG. 2 is a diagram schematically showing volume data representing the blood vessel morphology. The extraction unit 61 extracts volume data 10 representing the form of blood vessels distributed in a three-dimensional space, as shown in FIG. 2, from the volume data acquired by transmission and reception of ultrasonic waves.

  Then, the extraction unit 61 outputs volume data representing the blood vessel form to the color assignment unit 65 of the color arrangement unit 62. Further, the extraction unit 61 outputs information (coordinate information) indicating the position of the blood vessel in the three-dimensional space to the control unit 9.

  The image processing unit 6 may read volume data from the data storage unit 5 and generate a plurality of tomographic image data along a predetermined direction based on the volume data. In this case, the image processing unit 6 reconstructs the volume data based on the plurality of tomographic image data. The extraction unit 61 may extract volume data representing a blood vessel form from the reconstructed volume data. Then, the extracting unit 61 outputs volume data representing the blood vessel form to the color assigning unit 65. Further, the extraction unit 61 outputs information (coordinate information) indicating the position of the blood vessel in the three-dimensional space to the control unit 9.

  The observation point setting unit 91 of the control unit 9 receives the coordinate information of the blood vessel in the three-dimensional space from the extraction unit 61 and sets a plurality of observation points (sample positions) along the blood vessel in the three-dimensional space. This observation point has a predetermined size in the three-dimensional space and occupies a predetermined range in the three-dimensional space. The range specified by the observation point is a range to be subjected to Doppler scan, and blood flow information at the observation point is acquired. Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3. The observation point setting unit 91 corresponds to an example of “observation point setting means” of the present invention.

  The transmission / reception unit 3 deflects the ultrasonic beam by the ultrasonic probe 2 in accordance with the coordinate information of the observation point set by the control unit 9 and performs Doppler scan by the pulse Doppler method, thereby performing Doppler information (blood flow) of each observation point. Information). Then, the transmission / reception unit 3 outputs the Doppler information of each observation point obtained by the Doppler scan to the Doppler processing unit 42. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information output from the transmission / reception unit 3. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color arrangement unit 62. Further, the Doppler processing unit 42 outputs the coordinate information of each observation point and the blood flow velocity at each observation point in the three-dimensional space to the data storage unit 5. The data storage unit 5 stores coordinate information and blood flow velocity at each observation point.

  The ultrasonic probe 2, the transmission / reception unit 3, and the signal processing unit 4 correspond to an example of the “flow velocity acquisition unit” of the present invention.

  The color determination unit 63 of the color arrangement unit 62 receives the blood flow velocity at each observation point from the Doppler processing unit 42 and determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point. For example, a color table in which the magnitude and color of the blood flow velocity are associated with each other is stored in advance in a storage unit (not shown). The color determination unit 63 determines a color for each observation point according to the blood flow velocity at each observation point in accordance with the association stored in the storage unit. For example, blue is associated with a small blood flow velocity (slow blood flow velocity), and red is associated with a large blood flow velocity (fast blood flow velocity). And the smaller the blood flow velocity (the slower the blood flow velocity), the blue line gradually corresponds to the strong color, and the larger the blood flow velocity (the faster the blood flow velocity), the red line Gradually respond to strong colors. Then, the color determination unit 63 sends information (coordinate information) indicating the position of each observation point in the three-dimensional space and information (color information) indicating the color determined for each observation point to the color allocation unit 65. Output. Note that the color determined by the color determination unit 63 may include the degree of color tone represented by the color density, brightness, darkness, and intensity in addition to the type of color.

  The color allocation unit 65 receives volume data representing the blood vessel form from the extraction unit 61, and further receives information (color information) indicating the color for each observation point from the color determination unit 63, and receives the information on each observation point of the volume data. The color determined by the color determining unit 63 is assigned to the color. That is, the color assignment unit 65 assigns a color corresponding to the magnitude of the blood flow velocity to the position of each observation point in the volume data. Then, the color assignment unit 65 outputs volume data to which a color corresponding to the magnitude of the blood flow velocity is assigned to the three-dimensional image generation unit 66. Note that volume data in which a color corresponding to the blood flow velocity is assigned to each unit is referred to as “color volume data” for convenience. The color assigning unit 65 outputs the color volume data to a data storage unit (not shown), and the data storage unit stores the color volume data. The color assigning unit 65 may assign the degree of the color tone determined by the color determining unit 63 in addition to the color type to each part of the volume data.

  The three-dimensional image generation unit 66 sets a viewpoint for volume data (color volume data) to which a color corresponding to the magnitude of the blood flow velocity is assigned, and in the line-of-sight direction from the viewpoint toward the color volume data. By performing volume rendering along, three-dimensional image data representing a blood vessel in three dimensions is generated. Then, the 3D image generation unit 66 outputs the 3D image data to the display control unit 7. The operator can set the viewpoint at an arbitrary position by designating an arbitrary position using the operation unit 82. The three-dimensional image generation unit 66 outputs the three-dimensional image data to a data storage unit (not shown), and the data storage unit stores the three-dimensional image data.

  The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data. As a result, a three-dimensional image representing the blood vessel in a three-dimensional manner is displayed on the display unit 81, and a color corresponding to the blood flow velocity is assigned to each part of the blood vessel and displayed. When the color assigning unit 65 assigns to each part of the volume data a degree of color tone corresponding to the magnitude of the blood flow velocity, the magnitude of the blood flow velocity is represented by the degree of the color tone.

  The volume data (color volume data) to which colors are assigned by the color assigning unit 65 and the 3D image data generated by the 3D image generating unit 66 are stored in a data storage unit (not shown). The 3D image generation unit 66 may generate 3D image data by reading color volume data from the data storage unit and performing volume rendering on the color volume data. The display control unit 7 may read the 3D image data from the data storage unit and cause the display unit 81 to display a 3D image based on the 3D image data.

  The control unit 9 controls the operation of each unit of the ultrasonic diagnostic apparatus 1. For example, the control unit 9 controls transmission / reception of ultrasonic waves by the transmission / reception unit 3. The transmission / reception unit 3 acquires volume data of the subject by performing a volume scan with the ultrasonic probe 2 under the control of the control unit 9. Further, the transmission / reception unit 3 acquires Doppler information of the subject by performing Doppler scan with the ultrasonic probe 2 under the control of the control unit 9.

  Here, an example of setting observation points (sample positions) will be described with reference to FIGS. In this embodiment, as an example, the first setting method to the fourth setting method will be described.

(First setting method)
First, the first setting method will be described with reference to FIG. FIG. 3 is a schematic diagram showing a first setting method of observation points (sample positions) for blood vessels. Each observation point has a predetermined size and occupies a predetermined area. Based on the coordinate information of the blood vessels in the three-dimensional space, the observation point setting unit 91 overlaps a part of the observation points 12A, 12B,... 12N,... Are set. That is, the observation point setting unit 91 sets the observation points so that the observation points adjacent to each other along the blood vessel 11 partially overlap each other. Since each observation point has a predetermined size, it can be set to partially overlap each other. For example, the observation point setting unit 91 sets the observation point 12A and the observation point 12B along the blood vessel 11 so that a part of the observation point 12A overlaps a part of the observation point 12B adjacent to the observation point 12A. The observation point setting unit 91 sets the observation point 12B and the observation point 12C along the blood vessel 11 so that a part of the observation point 12B overlaps a part of the observation point 12C adjacent to the observation point 12B. In this way, the observation point setting unit 91 sets each observation point adjacent along the blood vessel 11 at a position where a part thereof overlaps. For example, the overlapping range is stored in a storage unit (not shown). The observation point setting unit 91 sets each observation point adjacent along the blood vessel 11 at a position where a part thereof overlaps according to the overlapping range stored in the storage unit. Note that the operator can arbitrarily change the size of the overlapping range using the operation unit 82. Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3.

  The transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point by performing a Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. In the example shown in FIG. 3, the transmitting / receiving unit 3 performs Doppler scan on the observation points 12A, 12B, 12C,... Doppler information (blood flow information) is acquired. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color determination unit 63.

  The color determination unit 63 receives the blood flow velocity at each observation point from the Doppler processing unit 42 and determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point. As described above, the color determination unit 63 determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point in accordance with the association indicated by the color table stored in the storage unit (not shown). . In the example illustrated in FIG. 3, the color determination unit 63 determines a color for the observation point 12A and the like according to the blood flow velocity at the observation points 12A, 12B,. Then, the color determination unit 63 outputs information (coordinate information) indicating the position of each observation point and information (color information) indicating the color determined for each observation point to the color assignment unit 65.

  The color assignment unit 65 receives volume data representing the blood vessel form from the extraction unit 61, and further receives information (color information) indicating the color for each observation point from the color decision unit 63, and receives volume data representing the blood vessel form. The color determined by the color determination unit 63 is assigned to each observation point. In the example shown in FIG. 3, the color assignment unit 65 is determined by the color determination unit 63 at the positions of the observation points 12A, 12B,..., 12N,. Assign a different color.

  Then, the color assignment unit 65 outputs volume data (color volume data) to which a color corresponding to the blood flow velocity is assigned to the three-dimensional image generation unit 66.

  The color assigning unit 65 aligns the observation points based on the pattern and color in a range overlapping with adjacent observation points, and assigns a color to each observation point of the volume data. This makes it possible to perform alignment between the observation points with high accuracy.

  The three-dimensional image generation unit 66 sets a viewpoint for the color volume data, and performs volume rendering along the line-of-sight direction from the viewpoint toward the color volume data, so that the three-dimensional image data that represents the blood vessel three-dimensionally Is generated. Then, the 3D image generation unit 66 outputs the 3D image data to the display control unit 7.

  The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data. As a result, a three-dimensional image representing the blood vessel in a three-dimensional manner is displayed on the display unit 81, and a color corresponding to the blood flow velocity is assigned to each part of the blood vessel and displayed.

  Here, FIG. 4 shows an example of a three-dimensional image generated by the ultrasonic diagnostic apparatus 1 according to this embodiment. FIG. 4 is a diagram showing an example of a three-dimensional image generated by the ultrasonic diagnostic apparatus according to the embodiment of the present invention.

  As shown in FIG. 4, the display control unit 7 displays a three-dimensional image 20 in which a blood vessel is three-dimensionally represented and a color corresponding to the blood flow velocity is assigned to each unit on the display unit 81. In addition, the display control unit 7 causes the display unit 81 to display the color bar 22 indicating the association between the blood flow velocity magnitude and the color. In FIG. 4, instead of using color to represent the magnitude of the blood flow velocity, the hatching pattern is changed according to the blood flow velocity for convenience. For example, the smaller the blood flow velocity (the slower the blood flow velocity), the blue line gradually corresponds to a stronger color, and the larger the blood flow velocity (the faster the blood flow velocity), the red line Gradually respond to strong colors. That is, the gradation is gradually changed according to the blood flow velocity.

  By observing the three-dimensional image 20 displayed on the display unit 81, the operator can grasp the three-dimensional shape of the blood vessel and the blood flow velocity in each part of the blood vessel at a time. That is, since the color corresponding to the blood flow velocity is assigned to the three-dimensional image 20 that represents the shape of the blood vessel three-dimensionally, the position of the blood vessel in the three-dimensional space and the velocity of the blood flow flowing through the blood vessel. It becomes possible to grasp clearly.

  For example, a blood vessel stenosis may have occurred in a part such as the part 21 where the blood flow velocity is slower than other parts. Therefore, by observing the three-dimensional image 20, the operator can clearly identify a portion where there is a possibility of blood vessel stenosis.

  In addition, according to the first setting method, since a part of the observation points is overlapped with the adjacent observation points, the blood flow velocity of the blood vessel can be acquired without leaving a gap. Therefore, it is possible to obtain the blood flow velocity in each part of the blood vessel with high accuracy.

(Second setting method)
Next, the second setting method will be described with reference to FIG. FIG. 5 is a schematic diagram showing a second setting method of observation points (sample positions) for blood vessels. The observation point setting unit 91 has observation points (sample positions) 12A, 12B, 12C at predetermined intervals along the blood vessel 11 in the three-dimensional space, based on the coordinate information of the blood vessels in the three-dimensional space. ... is set. That is, the observation point setting unit 91 sets the observation points adjacent along the blood vessel 11 at a predetermined interval. For example, the observation point setting unit 91 sets the observation point 12B adjacent to the observation point 12A at a position away from the observation point 12A by a predetermined distance. The observation point setting unit 91 sets the observation point 12C adjacent to the observation point 12B at a position away from the observation point 12B by a predetermined distance. As described above, the observation point setting unit 91 sets the observation points adjacent along the blood vessel 11 at positions separated from each other by a predetermined distance. For example, the distance between observation points (predetermined interval) is stored in a storage unit (not shown). The observation point setting unit 91 sets the observation points adjacent along the blood vessel 11 at positions separated from each other by a predetermined distance according to the predetermined interval stored in the storage unit. The operator can change the distance (predetermined interval) between the observation points to an arbitrary distance (interval) using the operation unit 82. Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3.

  The transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point by performing a Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. In the example shown in FIG. 5, the transmitting / receiving unit 3 performs Doppler scan on the observation points 12A, 12B, 12C,. Flow information). The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color determination unit 63.

  As described above, the color determination unit 63 determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point in accordance with the association indicated by the color table stored in the storage unit (not shown). . In the example shown in FIG. 5, the color determination unit 63 determines the color for the observation point 12A according to the magnitude of the blood flow velocity at the observation point 12A, and according to the magnitude of the blood flow velocity at the observation point 12B. The color for the observation point 12B is determined, and the color for the observation point 12C is determined according to the blood flow velocity at the observation point 12C. Then, the color determination unit 63 outputs information (coordinate information) indicating the position of each observation point and information (color information) indicating the color determined for each observation point to the color assignment unit 65.

  As described above, the color assigning unit 65 assigns the color determined by the color determining unit 63 to each observation point of the volume data representing the blood vessel form. In the example shown in FIG. 5, the color assigning unit 65 assigns the color determined by the color determining unit 63 to the position of the observation point 12A and the position of the observation point 12B to the volume data representing the blood vessel form. The color determined by the color determination unit 63 is allocated, and the color determined by the color determination unit 63 is allocated to the position of the observation point 12C. Then, the color assignment unit 65 outputs volume data (color volume data) to which a color corresponding to the blood flow velocity is assigned to the three-dimensional image generation unit 66.

  The three-dimensional image generation unit 66 sets a viewpoint for the color volume data, and performs volume rendering along the line-of-sight direction from the viewpoint toward the color volume data, so that the three-dimensional image data that represents the blood vessel three-dimensionally Is generated. Then, the 3D image generation unit 66 outputs the 3D image data to the display control unit 7.

  The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data. As a result, a three-dimensional image representing the blood vessel in a three-dimensional manner is displayed on the display unit 81, and a color corresponding to the blood flow velocity is assigned to each part of the blood vessel and displayed.

  As described above, since the color corresponding to the magnitude of the blood flow velocity is assigned to the three-dimensional image that three-dimensionally represents the shape of the blood vessel, the position of the blood vessel in the three-dimensional space and the blood flow that flows through the blood vessel. It is possible to clearly grasp the speed of the.

  In the second setting method, since each observation point (sample position) is set at a predetermined interval, the spatial resolution of the blood flow velocity is reduced. However, since the number of locations where Doppler scanning is performed is relatively small, the time required from scanning to image display can be shortened. That is, it is possible to acquire and display in real time an image representing the form of a blood vessel in three dimensions and blood flow information of each part. The second setting method is effective for roughly grasping blood flow information in the initial stage of ultrasonic diagnosis. When acquiring blood flow information in detail, it is possible to cope by increasing the number of observation points. For example, in the initial stage of ultrasonic diagnosis, blood flow velocity is roughly grasped by setting a small number of observation points, and then blood flow information is acquired in detail by increasing the number of observation points.

(Interpolation of blood flow velocity)
In the second setting method, since each observation point is set at a predetermined interval, in a range between adjacent observation points along the blood vessel (hereinafter sometimes referred to as “interpolation range”). The blood flow velocity is not sought. As a result, an assigned color is not determined for the interpolation range. Therefore, the interpolation unit 64 obtains the blood flow velocity in the interpolation range by interpolation based on the blood flow velocity at each observation point. For example, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the adjacent observation points by an interpolation method such as linear interpolation or spline interpolation based on the blood flow velocity at the adjacent observation points along the blood vessel. Then, the interpolation unit 64 outputs the blood flow velocity in the interpolation range to the color determination unit 63.

  The color determination unit 63 receives the blood flow velocity in the interpolation range from the interpolation unit 64, and determines a color for the interpolation range according to the magnitude of the blood flow velocity in the interpolation range. Then, the color determination unit 63 outputs information (coordinate information) indicating the position of the interpolation range in the three-dimensional space and information (color information) indicating the color determined for the interpolation range to the color allocation unit 65. To do. The color allocation unit 65 receives information (color information) indicating the color for the interpolation range from the color determination unit 63, and allocates the color determined by the color determination unit 63 to the interpolation range of the volume data representing the blood vessel form. . As a result, in the volume data representing the blood vessel morphology, a color obtained by actual measurement is assigned to each observation point, and a color obtained by interpolation is assigned to the interpolation range. Then, the color assignment unit 65 outputs volume data (color volume data) in which a color is assigned to each part to the three-dimensional image generation unit 66. The three-dimensional image generation unit 66 generates three-dimensional image data by performing volume rendering on the color volume data.

  Here, an example of interpolation will be described with reference to FIG. FIG. 6 is a diagram for explaining an interpolation method between observation points (sample positions). For example, as shown in FIG. 6A, the blood flow velocity is determined for each of the observation points 12A and 12B, and the colors are determined. On the other hand, the blood flow velocity is not obtained for the interpolation range 11a between the observation points 12A and 12B adjacent along the blood vessel 11. As a result, the assigned color is not determined for the interpolation range 11a.

  Therefore, the interpolation unit 64 receives the coordinate information of the observation points 12A and 12B and the blood flow velocity from the Doppler processing unit 42, and interpolates between the observation points 12A and 12B adjacent along the blood vessel 11. The blood flow velocity in 11a is obtained. For example, the interpolation unit 64 obtains the blood flow velocity in the interpolation range 11a by an interpolation method such as linear interpolation or spline interpolation. At this time, the interpolation unit 64 may obtain the blood flow velocity of each part included in the interpolation range 11a so that the blood flow velocity gradually changes from the observation point 12A to the observation point 12B. Then, the interpolation unit 64 outputs the blood flow velocity in the interpolation range 11a to the color determination unit 63.

  The color determination part 63 determines the color according to the magnitude | size of the blood flow velocity with respect to the interpolation range 11a. Then, the color determination unit 63 uses information (coordinate information) indicating the position of the interpolation range 11a in the three-dimensional space and information (color information) indicating the color determined for the interpolation range 11a as a color allocation unit 65. Output to.

  The color allocation unit 65 receives information (color information) indicating the color for the interpolation range 11a from the color determination unit 63, and the color determined by the color determination unit 63 for the interpolation range 11a of the volume data representing the blood vessel form. Assign. As a result, for example, as shown in FIG. 6B, the color obtained by the interpolation is assigned to the interpolation range 11a.

  The interpolation unit 64 also obtains a blood flow velocity by interpolation for an interpolation range other than the interpolation range 11a. The color determination unit 63 determines a color corresponding to the blood flow velocity of each interpolation range for each of the plurality of interpolation ranges. The color assigning unit 65 assigns the color determined by the color determining unit 63 to the interpolation range in the volume data representing the blood vessel form. As a result, a color corresponding to the magnitude of the blood flow velocity is assigned to the entire range of the volume data representing the blood vessel morphology.

  Then, the three-dimensional image generation unit 66 generates three-dimensional image data by performing volume rendering on the volume data (color volume data) in which colors are assigned to the respective units. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data. For example, as illustrated in FIG. 4, the display control unit 7 causes the display unit 81 to display a three-dimensional image 20 in which a color corresponding to the blood flow velocity is assigned to each unit.

  As described above, even when the number of observation points is small, it is possible to assign and display colors for the entire blood vessel by obtaining the blood flow velocity between the observation points by interpolation. .

(Third setting method)
Next, a third setting method will be described with reference to FIG. FIG. 7 is a schematic diagram showing a third setting method of observation points (sample positions) for blood vessels. In the third setting method, a region of interest (ROI) is designated in advance in a three-dimensional space scanned by ultrasonic waves. The region of interest (ROI) can be specified using the operation unit 82 by the operator. For example, three-dimensional image data is generated in advance by the three-dimensional image generation unit 66 by scanning the subject in advance with ultrasound. Then, the display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data. The operator designates a region of interest (ROI) at a desired position using the operation unit 82 while observing the three-dimensional image. Information (coordinate information) indicating the position of the region of interest (ROI) in the three-dimensional space is output from the user interface (UI) 8 to the control unit 9, and the region of interest (ROI) is set in the control unit 9.

  The observation point setting unit 91 sets an observation point (sample position) along the blood vessel 11 in the three-dimensional space based on the coordinate information of the blood vessel in the three-dimensional space and the coordinate information of the region of interest. At this time, the observation point setting unit 91 overlaps a part of the range in which the region of interest (ROI) 13 is set with adjacent observation points in the same manner as the first setting method described above. Set 12C. In addition, the observation point setting unit 91 sets the observation points (sample positions) 12D and 12E at predetermined intervals for the range other than the region of interest (ROI) 13, as in the second setting method described above. , ... are set.

  For example, for the range in which the region of interest (ROI) 13 is set, the observation point setting unit 91 determines the observation point 12A and the observation point 12A so that a part of the observation point 12A overlaps a part of the observation point 12B adjacent to the observation point 12A. An observation point 12B is set along the blood vessel 11. The observation point setting unit 91 sets the observation point 12B and the observation point 12C along the blood vessel 11 so that a part of the observation point 12B overlaps a part of the observation point 12C adjacent to the observation point 12B.

  On the other hand, for a range other than the region of interest (ROI) 13, the observation point setting unit 91 sets an observation point 12D adjacent to the observation point 12C at a position away from the observation point 12C by a predetermined distance. The observation point setting unit 91 sets the observation point 12E adjacent to the observation point 12D at a position away from the observation point 12D by a predetermined distance.

  Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3.

  The transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point by performing a Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. In the example illustrated in FIG. 7, the transmission / reception unit 3 performs Doppler scans on observation points 12A, 12B, and 12C that partially overlap adjacent observation points in the region of interest 13, and further, ranges other than the region of interest 13 , Doppler scan is performed on the observation points 12D, 12E,... Set at predetermined intervals. Then, the transmission / reception unit 3 outputs the Doppler information (blood flow information) acquired by the Doppler scan to the Doppler processing unit 42. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color determination unit 63.

  As described above, the color determination unit 63 determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point in accordance with the association indicated by the color table stored in the storage unit (not shown). . Then, the color determination unit 63 outputs information (coordinate information) indicating the position of each observation point and information (color information) indicating the color determined for each observation point to the color assignment unit 65.

  As described above, the color assigning unit 65 assigns the color determined by the color determining unit 63 to each observation point of the volume data representing the blood vessel form. Then, the color assignment unit 65 outputs volume data (color volume data) to which a color corresponding to the blood flow velocity is assigned to the three-dimensional image generation unit 66.

  The three-dimensional image generation unit 66 sets a viewpoint for the color volume data, and performs volume rendering along the line-of-sight direction from the viewpoint toward the color volume data, thereby providing a three-dimensional image that represents the blood flow in a three-dimensional manner. Generate data. Then, the 3D image generation unit 66 outputs the 3D image data to the display control unit 7.

  The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data. As a result, a three-dimensional image representing the blood vessel in a three-dimensional manner is displayed on the display unit 81, and a color corresponding to the blood flow velocity is assigned to each part of the blood vessel and displayed.

  As described above, since the color corresponding to the magnitude of the blood flow velocity is assigned to the three-dimensional image that three-dimensionally represents the shape of the blood vessel, the position of the blood vessel in the three-dimensional space and the blood flow that flows through the blood vessel. It is possible to clearly grasp the speed of the.

  Further, according to the third setting method, in the region of interest 13, since a part of the observation points overlaps the adjacent observation points, the blood flow velocity of the blood vessel can be acquired without leaving a gap. Therefore, in the region of interest 13, the blood flow velocity in each part of the blood vessel can be obtained with high accuracy. On the other hand, in the range other than the region of interest 13, each observation point is set at a predetermined interval, so that there are relatively few places to perform Doppler scan. Since the number of places where Doppler scanning is performed is reduced, the time required for scanning can be reduced. As described above, according to the third setting method, it is possible to acquire and display an image representing the shape of a blood vessel in three dimensions and blood flow information of each part in real time, and further, a point of interest (region of interest) ), Blood flow information can be obtained with high accuracy.

(Interpolation of blood flow velocity)
In the third setting method, the observation points are set at predetermined intervals in a range other than the region of interest (ROI) 13. Therefore, in the range other than the region of interest (ROI) 13, the blood flow velocity is not obtained in the range (interpolation range) between observation points adjacent along the blood vessel, as in the second setting method described above. Therefore, the interpolation unit 64 obtains a blood flow velocity in the interpolation range by interpolation for a range other than the region of interest (ROI) 13.

  For example, as shown in FIG. 7, since the observation point 12D is not included in the region of interest 13, the observation point 12D is set at a predetermined interval from the observation point 12C included in the region of interest 13. Therefore, the blood flow velocity is not obtained for the range (interpolation range) between the observation point 12C and the observation point 12D adjacent to the observation point 12C. Further, since the observation point 12E is not included in the region of interest 13, the blood flow velocity is not obtained for the range (interpolation range) between the observation point 12D and the observation point 12E adjacent along the blood vessel 11. . As a result, the assigned color is not determined for the range between the observation point 12C and the observation point 12D or the range between the observation point 12D and the observation point 12E.

  Therefore, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the observation point 12C and the observation point 12D adjacent along the blood vessel 11. Similarly, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the observation points 12D and 12E adjacent along the blood vessel 11. Then, the interpolation unit 64 outputs the blood flow velocity in the interpolation range to the color determination unit 63.

  The color determination unit 63 determines a color corresponding to the blood flow velocity with respect to the interpolation range. The color assigning unit 65 assigns the color determined by the color determining unit 63 to the interpolation range of the volume data representing the blood vessel form. As a result, in the volume data representing the blood vessel morphology, a color obtained by actual measurement is assigned to each observation point, and a color obtained by interpolation is assigned to the interpolation range. As a result, a color corresponding to the magnitude of the blood flow velocity is assigned to the entire range of the volume data representing the blood vessel morphology.

  In the third setting method, for the region of interest 13, since a part of each observation point overlaps with an adjacent observation point, only the color obtained by actual measurement is assigned to the region of interest 13. On the other hand, in the range other than the region of interest 13, since each observation point is set at a predetermined interval, a color obtained by actual measurement and a color obtained by interpolation are mixedly assigned. Then, the color assignment unit 65 outputs volume data (color volume data) in which a color is assigned to each part to the three-dimensional image generation unit 66. The three-dimensional image generation unit 66 generates three-dimensional image data by performing volume rendering on the color volume data. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data. For example, as illustrated in FIG. 4, the display control unit 7 causes the display unit 81 to display a three-dimensional image 20 in which a color corresponding to the blood flow velocity is assigned to each unit.

  As described above, the range other than the region of interest 13 can be displayed by assigning a color to the entire blood vessel by obtaining the blood flow velocity between the observation points by interpolation.

(Fourth setting method)
Next, a fourth setting method will be described with reference to FIG. FIG. 8 is a schematic diagram showing a fourth setting method of observation points (sample positions) for blood vessels. In the fourth setting method, observation points are finely set within a predetermined range including a blood vessel branch point, and the observation points are coarsely set in other ranges. Specific processing contents will be described below.

  The observation point setting unit 91 sets an observation point (sample position) along the blood vessel 11 in the three-dimensional space based on the coordinate information of the blood vessel in the three-dimensional space. At this time, the observation point setting unit 91 detects a branch point of the blood vessel 11. As a branching point detection method, a method according to the prior art can be used. For example, the observation point setting unit 91 thins the blood vessel 11 and specifies a branching point. And the observation point setting part 91 sets the ranges 14 and 15 including the branch point of the blood vessel 11, as shown in FIG. The widths of the ranges 14 and 15 are set in the observation point setting unit 91 in advance. Note that the width of the predetermined range including the branch point may be arbitrarily changed by the operator using the operation unit 82.

  And the observation point setting part 91 sets the space | interval between each observation point comparatively short in the ranges 14 and 15 including a branch point, and about intervals other than the ranges 14 and 15, the space | interval between each observation point. Is set relatively long. For example, as shown in FIG. 8, the observation point setting unit 91 overlaps a part of the observation points 12A and 12B with the adjacent observation points in the range 14 including the branch point, as in the first setting method described above. , 12C are set. In addition, the observation point setting unit 91 sets observation points 12D, 12E, and 12F by overlapping a part of the observation points adjacent to each other in the range 15 including the branch point. On the other hand, the observation point setting unit 91 sets each observation point at a predetermined interval in the range other than the ranges 14 and 15 including the branch point, similarly to the second setting method described above.

  For example, for the range 14 including the bifurcation point, the observation point setting unit 91 connects the observation point 12A and the observation point 12B to the blood vessel so that a part of the observation point 12A overlaps a part of the observation point 12B adjacent to the observation point 12A. 11 is set. The observation point setting unit 91 sets the observation point 12B and the observation point 12C along the blood vessel 11 so that a part of the observation point 12B overlaps a part of the observation point 12C adjacent to the observation point 12B.

  In addition, for the range 15 including the branch point, the observation point setting unit 91 sets the observation point 12D and the observation point 12E as blood vessels so that a part of the observation point 12D overlaps a part of the observation point 12E adjacent to the observation point 12D. 11 is set. The observation point setting unit 91 sets the observation point 12E and the observation point 12F along the blood vessel 11 so that a part of the observation point 12E overlaps a part of the observation point 12F adjacent to the observation point 12E.

  On the other hand, for ranges other than the ranges 14 and 15 including the branch point, the observation point setting unit 91 sets the observation point 12M adjacent to the observation point 12A at a position away from the observation point 12A by a predetermined distance. The observation point setting unit 91 sets the observation point 12N adjacent to the observation point 12F at a position away from the observation point 12F by a predetermined distance.

  Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3.

  The transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point by performing a Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. In the example shown in FIG. 8, the transmitter / receiver 3 performs Doppler scan on the observation points 12A, 12B, and 12C that partially overlap the adjacent observation points within the range 14 including the branch point of the blood vessel 11, In the range 15 including the branch point of the blood vessel 11, Doppler scan is performed on the observation points 12D, 12E, and 12F that partially overlap the adjacent observation points. Further, in the range other than the ranges 14 and 15 including the branch points, the transmission / reception unit 3 performs Doppler scan on the observation points 12M, 12N,. Then, the transmission / reception unit 3 outputs the Doppler information (blood flow information) acquired by the Doppler scan to the Doppler processing unit 42. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color determination unit 63.

  As described above, the color determination unit 63 determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point in accordance with the association indicated by the color table stored in the storage unit (not shown). . Then, the color determination unit 63 outputs information (coordinate information) indicating the position of each observation point and information (color information) indicating the color determined for each observation point to the color assignment unit 65.

  As described above, the color assigning unit 65 assigns the color determined by the color determining unit 63 to each observation point of the volume data representing the blood vessel form. Then, the color assignment unit 65 outputs volume data (color volume data) to which a color corresponding to the blood flow velocity is assigned to the three-dimensional image generation unit 66.

  The three-dimensional image generation unit 66 sets a viewpoint for the color volume data, and performs volume rendering along the line-of-sight direction from the viewpoint toward the color volume data, so that the three-dimensional image data that represents the blood vessel three-dimensionally Is generated. Then, the 3D image generation unit 66 outputs the 3D image data to the display control unit 7.

  The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data. As a result, a three-dimensional image representing the blood vessel in a three-dimensional manner is displayed on the display unit 81, and a color corresponding to the blood flow velocity is assigned to each part of the blood vessel and displayed.

  As described above, since the color corresponding to the blood flow velocity is assigned to the three-dimensional image that three-dimensionally represents the shape of the blood vessel, the position of the blood vessel in the three-dimensional space and the blood flow that flows through the blood vessel. It is possible to clearly grasp the speed of the.

  Further, according to the fourth setting method, in the ranges 14 and 15 including the branching point of the blood vessel 11, since a part of the observation point overlaps with the adjacent observation point, the blood flow velocity of the blood vessel is acquired without leaving a gap. It becomes possible to do. Therefore, near the branch point of the blood vessel 11, the blood flow velocity in each part of the blood vessel can be obtained with high accuracy. On the other hand, in the ranges other than the ranges 14 and 15 including the branch points, the observation points are set at predetermined intervals, so that the number of places where the Doppler scan is performed is relatively small. Since the number of places where Doppler scanning is performed is reduced, the time required for scanning can be reduced. As described above, according to the fourth setting method, it is possible to acquire and display an image representing the shape of a blood vessel in three dimensions and blood flow information of each part in real time, and further, a point of interest (the blood vessel At the bifurcation point, blood flow information can be obtained with high accuracy.

(Interpolation of blood flow velocity)
In the fourth setting method, the observation points are set at predetermined intervals in a range other than the ranges 14 and 15 including the branch point of the blood vessel 11. Therefore, in the ranges other than the ranges 14 and 15, the blood flow velocity is not obtained in the range (interpolation range) between the observation points adjacent along the blood vessel, as in the second setting method described above. Therefore, the interpolation unit 64 obtains the blood flow velocity in the interpolation range by interpolation for a range other than the ranges 14 and 15 including the branch point.

  For example, as shown in FIG. 8, since the observation point 12M is not included in the ranges 14 and 15 including the branch point, the observation point 12M is set at a predetermined interval from the observation point 12A included in the range 14. . Therefore, the blood flow velocity is not obtained for the range (interpolation range) between the observation point 12A and the observation point 12M adjacent to the observation point 12A. Further, since the observation point 12N is not included in the range 15, the blood flow velocity is not obtained for the range (interpolation range) between the observation point 12F and the observation point 12N adjacent along the blood vessel 11. Further, in the example shown in FIG. 8, there is an observation point between the observation point 12C set at the end of the range 14 including the branch point and the observation point 12D set at the end of the range 15 including the branch point. Is not set, the blood flow velocity is not obtained for the range (interpolation range) between the observation point 12C and the observation point 12D. As a result, the range between the observation point 12A and the observation point 12M, the range between the observation point 12F and the observation point 12N, and the range between the observation point 12C and the observation point 12D are assigned. The color has not been determined.

  Therefore, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the observation point 12A and the observation point 12M adjacent along the blood vessel 11. Similarly, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the observation point 12F and the observation point 12N adjacent along the blood vessel 11. Further, the interpolation unit 64 obtains the blood flow velocity in the interpolation range between the observation point 12C and the observation point 12D adjacent along the blood vessel 11. Then, the interpolation unit 64 outputs the blood flow velocity in the interpolation range to the color determination unit 63.

  The color determination unit 63 determines a color corresponding to the blood flow velocity with respect to the interpolation range. The color assigning unit 65 assigns the color determined by the color determining unit 63 to the interpolation range of the volume data representing the blood vessel form. As a result, in the volume data representing the blood vessel morphology, a color obtained by actual measurement is assigned to each observation point, and a color obtained by interpolation is assigned to the interpolation range. As a result, a color corresponding to the magnitude of the blood flow velocity is assigned to the entire range of the volume data representing the blood vessel morphology.

  In the fourth setting method, in the ranges 14 and 15 including the branching point of the blood vessel 11, a part of each observation point overlaps with an adjacent observation point. Therefore, the ranges 14 and 15 were obtained by actual measurement. Only colors are assigned. On the other hand, for the ranges other than the ranges 14 and 15 including the branch point, since the observation points are set at predetermined intervals, the color obtained by actual measurement and the color obtained by interpolation are mixed. Assigned. Then, the color assignment unit 65 outputs volume data (color volume data) in which a color is assigned to each part to the three-dimensional image generation unit 66. The three-dimensional image generation unit 66 generates three-dimensional image data by performing volume rendering on the color volume data. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data. For example, as illustrated in FIG. 4, the display control unit 7 causes the display unit 81 to display a three-dimensional image 20 in which a color corresponding to the blood flow velocity is assigned to each unit.

  As described above, the range other than the ranges 14 and 15 including the branch point can be displayed by assigning a color to the entire blood vessel by obtaining the blood flow velocity between the observation points by interpolation. It becomes.

  The first to fourth setting methods described above can be arbitrarily designated by the operator. For example, the display control unit 7 displays a selection screen for selecting the first to fourth setting methods on the display unit 81, and the operator designates a desired setting method using the operation unit 82. When the setting method is designated by the operator, the observation point setting unit 91 of the control unit 9 sets observation points along the blood vessel 11 according to the setting method corresponding to the designation.

(Angle correction)
Next, angle correction of the ultrasonic beam will be described with reference to FIG. FIG. 9 is a schematic view of a blood vessel for explaining the angle correction of the ultrasonic beam. When an ultrasonic beam is transmitted at an angle close to a right angle with respect to a blood vessel, it is difficult to accurately measure the blood flow velocity at that point. For example, even if the actual blood flow velocity at that location is several m / sec, the acquired blood flow velocity may be 0 m / sec (no flow velocity value). Accordingly, there is a possibility that a blue color is assigned to a portion where a red color is originally assigned to a three-dimensional image of a blood vessel. As a result, it becomes difficult to make a diagnosis more accurately.

  For example, as shown in FIG. 9A, when the direction in which the blood vessel 11 travels and the ultrasound beam transmission / reception direction 30 are substantially orthogonal, the blood flow velocity is not accurately measured at the observation point 17. As a result, a color different from the original color is assigned and displayed at the position of the observation point 17 in the three-dimensional image. For example, even when no vascular stenosis has occurred at the position of the observation point 17, the blood flow velocity at the observation point 17 is 0 m / sec. As a result, the blue color corresponding to the slow blood flow velocity is allocated and displayed at the position of the observation point 17 in the three-dimensional image. Thus, if a blue color is assigned to the position of the observation point 17, it will be difficult to clearly provide the operator with the position where the vascular stenosis has occurred.

  Therefore, the ultrasonic diagnostic apparatus 1 according to this embodiment specifies a location (correction location) where the transmission / reception direction of the ultrasonic beam and the direction in which the blood vessel travels are substantially orthogonal to each other, and the transmission / reception direction for the correction location The ultrasonic beam is transmitted / received by changing.

  The angle correction unit 92 of the control unit 9 receives the coordinate information of the blood vessel in the three-dimensional space from the extraction unit 61, and based on the coordinate information of the blood vessel, the blood vessel location (correction) that is substantially orthogonal to the transmission / reception direction of the ultrasonic beam. Location). For example, the angle correction unit 92 specifies a location (correction location) where the angle between the transmission / reception direction of the ultrasonic beam and the direction orthogonal to the blood vessel is less than a predetermined angle set in advance. As an example, the angle correction unit 92 specifies a location (correction location) where the angle between the transmission / reception direction of the ultrasonic beam and the direction orthogonal to the blood vessel is less than ± 30 °. Then, the angle correction unit 92 sets the transmission angle of the ultrasonic beam with respect to the correction location to an angle of ± 30 ° or more with respect to the direction orthogonal to the blood vessel. At this time, the angle to be set can be designated in advance by the operator using the operation unit 82. For example, when 35 ° is designated by the operator, the angle correction unit 92 sets the transmission angle of the ultrasonic beam with respect to the correction location to 35 ° with respect to the direction orthogonal to the blood vessel.

  The control unit 9 outputs coordinate information of each observation point in the three-dimensional space and information (correction angle information) indicating the transmission angle of the ultrasonic beam with respect to the correction location to the transmission / reception unit 3.

  The transmission / reception unit 3 obtains Doppler information (blood flow information) at each observation point by deflecting the ultrasonic beam according to the coordinate information of the observation point set by the control unit 9 and performing Doppler scan by the pulse Doppler method. . At this time, the transmission / reception unit 3 acquires Doppler information of the correction location by deflecting the ultrasonic beam according to the correction angle information set by the control unit 9. In the example shown in FIG. 9B, the transmission / reception unit 3 transmits Doppler information of the observation point 17 by transmitting an ultrasonic beam from the transmission / reception direction 31 set to an angle of 30 ° or more to the observation point 17. To get. Then, the transmission / reception unit 3 outputs the Doppler information (blood flow information) acquired by the Doppler scan to the Doppler processing unit 42. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color determination unit 63.

  As described above, the color determination unit 63 determines a color for each observation point according to the magnitude of the blood flow velocity at each observation point. The color assigning unit 65 assigns the color determined by the color determining unit 63 to the volume data representing the blood vessel form. Then, the three-dimensional image generation unit 66 performs volume rendering on the volume data (color volume data) to which a color corresponding to the magnitude of the blood flow velocity is assigned, thereby generating three-dimensional image data that represents the blood vessel in three dimensions. Generate. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data.

  As described above, by changing the transmission / reception direction of the ultrasonic beam with respect to the observation point 17, as shown in FIG. 9B, the observation point 17 is assigned a color corresponding to the original blood flow velocity. It is done. As a result, a diagnosis based on the blood flow velocity can be performed more accurately. For example, since the position where the vascular stenosis has occurred can be clearly displayed as an image, it is possible to more accurately determine whether or not the vascular stenosis has occurred.

  Note that the angle correction by the angle correction unit 92 can be applied to any of the first to fourth setting methods described above.

(Acquisition of 3D image corresponding to cardiac phase)
In addition, by using an electrocardiogram waveform (ECG signal) of the subject, a blood flow velocity in each cardiac phase may be acquired, and a three-dimensional image in each cardiac phase may be generated. An example of acquiring three-dimensional image data corresponding to the cardiac phase will be described with reference to FIG. FIG. 10 is a diagram illustrating a three-dimensional image corresponding to the cardiac time phase.

  For example, an electrocardiogram waveform (ECG signal) of the subject is acquired using an electrocardiograph, the control unit 9 receives a trigger signal from the outside of the ultrasonic diagnostic apparatus 1, and the transmitter / receiver 3 performs super Controls the transmission and reception of sound waves. For example, a signal generator that generates a trigger signal when an R wave is detected by an electrocardiograph is provided, and the trigger signal is output to the control unit 9. The control unit 9 controls transmission / reception of ultrasonic waves by the transmission / reception unit 3 according to the trigger signal. Alternatively, an electrocardiographic waveform (ECG signal) may be input to the control unit 9 and the control unit 9 may detect an R wave. In this case, the control unit 9 controls transmission / reception of ultrasonic waves by the transmission / reception unit 3 in accordance with detection of the R wave.

  For example, the heart time phase in which the R wave is detected is set as a reference time phase, and the control unit 9 sets a predetermined delay time from the reference time phase, and the ultrasonic wave generated by the transmission / reception unit 3 corresponding to each heart time phase. Controls sending and receiving. Specifically, when receiving the trigger signal corresponding to the R wave, the control unit 9 outputs a transmission / reception instruction to the transmission / reception unit 3. When the transmission / reception unit 3 receives a transmission / reception instruction from the control unit 9, according to the instruction, the transmission / reception unit 3 performs Doppler scan on the observation point set by the control unit 9, thereby performing Doppler information (blood flow information) on each observation point. To get. And the Doppler process part 42 calculates | requires the blood flow velocity of each observation point based on the Doppler information. Thereby, the blood flow velocity in the cardiac phase of the R wave is acquired. Each observation point is set by any one of the first setting method to the fourth setting method described above.

  The control unit 9 then provides a predetermined delay time from the reference time phase, and outputs a transmission / reception instruction to the transmission / reception unit 3 for each cardiac time phase. Each time the transmission / reception unit 3 receives a transmission / reception instruction corresponding to each cardiac phase, the transmission / reception unit 3 performs Doppler scan on the observation point, thereby obtaining Doppler information (blood flow information) at each observation point for each cardiac phase. get. And the Doppler process part 42 calculates | requires the blood-flow velocity of each observation point in each cardiac time phase based on the Doppler information of each cardiac time phase. Thereby, the blood flow velocity in each cardiac time phase is acquired. The Doppler processing unit 42 outputs the blood flow velocity at each observation point in each cardiac time phase to the color determination unit 63. Further, the Doppler processing unit 42 outputs the blood flow velocity at each observation point in each cardiac time phase to the data storage unit 5, and the data storage unit 5 stores the blood flow velocity.

  For example, as shown in FIG. 10, by the control of the transmission / reception unit 3 by the control unit 9, the transmission / reception unit 3 performs Doppler scan in the cardiac phase of the P wave, and Doppler information ( Blood flow information). Similarly, the transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point in the cardiac phase corresponding to the Q wave, R wave, S wave, and T wave, respectively. And the Doppler process part 42 calculates | requires the blood-flow velocity of each observation point in the cardiac time phase corresponding to each of P wave, Q wave, R wave, S wave, and T wave.

  Then, the color determining unit 63 determines a color for each observation point in each cardiac phase according to the blood flow velocity at each observation point in each cardiac phase. The color assigning unit 65 assigns a color in each cardiac time phase to each observation point of the volume data representing the blood vessel morphology. Thus, volume data (color volume data) in which a color corresponding to the blood flow velocity is assigned to each observation point is generated for each cardiac time phase. Then, the three-dimensional image generation unit 66 performs volume rendering on the volume data (color volume data) to which the color at each cardiac phase is assigned, thereby generating the three-dimensional image data at each cardiac phase. Thereby, an image is obtained in which a color corresponding to the magnitude of the blood flow velocity acquired in each cardiac phase is assigned to the three-dimensional image that three-dimensionally represents the shape of the blood vessel.

  Volume data (color volume data) to which a color at each cardiac phase is assigned and three-dimensional image data at each cardiac phase are stored in a data storage unit (not shown). Then, the display control unit 7 reads the 3D image data in the cardiac phase designated by the operator from the data storage unit, and causes the display unit 81 to display a 3D image based on the 3D image data. Further, the display control unit 7 may cause the display unit 81 to sequentially display a three-dimensional image based on the three-dimensional image data of each cardiac phase for each cardiac phase.

  For example, as shown in FIG. 10, in the three-dimensional image 20P, a color corresponding to the magnitude of the blood flow velocity acquired in the cardiac phase of the P wave is assigned to the three-dimensional image that three-dimensionally represents the shape of the blood vessel. ing. In the three-dimensional image 20Q, a color corresponding to the magnitude of the blood flow velocity acquired in the cardiac phase of the Q wave is assigned to the three-dimensional image representing the blood vessel morphology. Each of the three-dimensional images 20R, 20S, and 20T is a three-dimensional image that represents the shape of a blood vessel, and has colors corresponding to the magnitudes of blood flow velocities acquired in the R, S, and T wave cardiac phases. Assigned.

  For example, when the operator designates the heart time phase of the R wave using the operation unit 82, the display control unit 7 accepts the designation, and stores the three-dimensional image data in the heart time phase of the R wave as a data storage unit (not shown). ) And display the three-dimensional image 20R based on the three-dimensional image data on the display unit 81. The display control unit 7 may display the three-dimensional images 20P, 20Q, 20R, 20S, and 20T on the display unit 81 in order.

  As described above, by generating 3D image data for each cardiac phase, the blood flow velocity in each cardiac phase can be grasped, and the presence or absence of blood vessel stenosis in each cardiac phase can be grasped. It becomes.

  Further, the transmission / reception unit 3 may acquire volume data for each cardiac phase under the control of the control unit 9. Then, the extraction unit 61 extracts volume data representing the vascular morphology in each cardiac phase from each of the volume data acquired in each cardiac phase. Then, the color assigning unit 65 assigns a color corresponding to the magnitude of the blood flow velocity acquired in the same cardiac time phase to the volume data representing the blood vessel morphology in each cardiac time phase. Generate color volume data. For example, the color assigning unit 65 responds to each observation point of the volume data representing the shape of the blood vessel acquired in the R-wave cardiac phase according to the magnitude of the blood flow velocity acquired in the R-wave cardiac phase. By assigning different colors, color volume data in the cardiac phase of the R wave is generated. Similarly, the color assignment unit 65 is acquired at the same cardiac time phase at each observation point of volume data representing the shape of the blood vessels acquired at the cardiac time phases of P wave, Q wave, S wave, and T wave. By assigning a color according to the magnitude of the blood flow velocity, color volume data in each cardiac phase is generated. Then, the three-dimensional image generation unit 66 performs volume rendering on the color volume data in each cardiac time phase, thereby generating three-dimensional image data in each cardiac time phase. As described above, the display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data of the cardiac phase specified by the operator. Thus, by acquiring volume data and blood flow velocity for each cardiac phase and generating three-dimensional image data for each cardiac phase, the operator can determine the position and blood flow of the blood vessels in each cardiac phase. It becomes possible to grasp the speed more accurately.

  The user interface 8 includes a display unit 81 and an operation unit 82. The display unit 81 includes a monitor such as a CRT or a liquid crystal display, and displays an ultrasonic image such as a three-dimensional image on the screen. In this embodiment, a three-dimensional image in which a color corresponding to the blood flow velocity is assigned to each part of the blood vessel is displayed on the display unit 81. The operation unit 82 includes a keyboard, a mouse, a trackball, or a TCS (Touch Command Screen), and various conditions such as an interval between observation points (sample positions) are designated by the operation of the operator.

  The image processing unit 6 includes a CPU and a storage device such as a ROM and a RAM. The storage device includes an extraction program for executing the function of the extraction unit 61, a color arrangement program for executing the function of the color arrangement unit 62, and an image generation program for executing the function of the three-dimensional image generation unit 66. It is remembered. The color arrangement program includes a color determination program for executing the function of the color determination unit 63, an interpolation program for executing the function of the interpolation unit 64, and a color allocation for executing the function of the color allocation unit 65. The program is included.

  When the CPU executes the extraction program, volume data representing blood vessels is extracted from the volume data acquired by scanning with ultrasonic waves. Further, the CPU executes a color determination program to determine a color according to the blood flow velocity at each observation point. In addition, when the CPU executes the interpolation program, the blood flow velocity in the interpolation range is obtained by interpolation. Further, the CPU executes the color assignment program to assign the determined color to the position of each observation point in the volume data representing the blood flow. Further, when the blood flow velocity in the interpolation range is obtained, the determined color is also assigned to the interpolation range in the volume data. Then, the CPU executes the image generation program to perform volume rendering on the volume data. As a result, three-dimensional image data in which the shape of the blood vessel is three-dimensionally represented and colors are assigned to the respective portions of the blood vessel is generated.

  The display control unit 7 includes a CPU and a storage device such as a ROM and a RAM. The storage device stores a display control program for executing the functions of the display control unit 7. When the CPU executes the display control program, the display unit 81 displays an ultrasonic image based on ultrasonic image data such as three-dimensional image data generated by the image processing unit 6.

  The control unit 9 includes a CPU and a storage device such as a ROM and a RAM. The storage device stores a control program for executing the function of the control unit 9. This control program includes a setting program for executing the function of the observation point setting unit 91 and an angle correction program for executing the function of the angle correction unit 92. The CPU sets the observation point along the blood vessel by executing the setting program. Further, the CPU corrects the transmission direction of the ultrasonic beam by executing the angle correction program. Further, the CPU controls the operation of each part of the ultrasonic diagnostic apparatus 1 by executing a control program. For example, when the CPU executes the control program, the transmission / reception unit 3 transmits / receives ultrasonic waves, and as a result, the volume data of the subject and the Doppler information of the subject are acquired.

  The extraction program, the color arrangement program, and the display control program constitute an example of the “ultrasonic image processing program” of the present invention.

(Operation)
Next, a series of operations by the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 11 is a flowchart showing a series of operations by the ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

(Step S01)
First, the volume data of the subject is acquired by scanning a three-dimensional region with the ultrasonic probe 2 and the transmission / reception unit 3. The signal processing unit 4 outputs the volume data to the extraction unit 61. The volume data is stored in the data storage unit 5.

(Step S02)
Next, the extraction unit 61 receives volume data from the signal processing unit 4 and extracts volume data 10 representing the form of blood vessels distributed in a three-dimensional space from the volume data as shown in FIG. The extraction unit 61 may read the volume data from the data storage unit 5 and extract the volume data 10 representing the blood vessel form from the volume data. For example, the extraction unit 61 extracts volume data representing the shape of a blood vessel using the extraction technique described in JP-A-8-131429. Then, the extraction unit 61 outputs volume data representing the blood vessel form to the color allocation unit 65 of the color arrangement unit 62, and further outputs coordinate information indicating the position of the blood vessel in the three-dimensional space to the control unit 9.

(Step S03)
The observation point setting unit 91 of the control unit 9 receives the coordinate information of the blood vessel in the three-dimensional space from the extraction unit 61, and based on the coordinate information, a plurality of observation points (sample positions) along the blood vessel in the three-dimensional space. Set. For example, the observation point setting unit 91 sets a plurality of observation points along the blood vessel according to the setting method designated in advance by the operator among the first to fourth setting methods described above.

(Step S04)
Furthermore, the angle correction unit 92 receives the coordinate information of the blood vessel in the three-dimensional space from the extraction unit 61, and based on the coordinate information of the blood vessel, the location (correction location) of the blood vessel that is substantially orthogonal to the transmission / reception direction of the ultrasonic beam. Is identified. For example, the angle correction unit 92 specifies a location (corrected location) where the angle between the transmission / reception direction of the ultrasonic beam and the direction orthogonal to the blood vessel is less than ± 30 °. Then, the angle correction unit 92 sets the transmission angle of the ultrasonic beam with respect to the correction location to an angle of ± 30 ° or more with respect to the direction orthogonal to the blood vessel.

(Step S05)
Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space and information (correction angle information) indicating the transmission angle of the ultrasonic beam with respect to the correction location to the transmission / reception unit 3. The transmission / reception unit 3 acquires Doppler information (blood flow information) at each observation point by performing a Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. At this time, the transmission / reception unit 3 acquires Doppler information of the correction location by deflecting the ultrasonic beam with the ultrasonic probe 2 in accordance with the correction angle information set by the control unit 9. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on the Doppler information acquired by the Doppler scan. Then, the Doppler processing unit 42 outputs information (coordinate information) indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color arrangement unit 62.

(Step S06)
The color determination unit 63 of the color arrangement unit 62 receives the blood flow velocity at each observation point from the Doppler processing unit 42 and determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point. For example, the color determination unit 63 determines the color for the observation point to be a strong blue color as the blood flow velocity decreases (as the blood flow velocity decreases). On the other hand, the color determination unit 63 determines the color for the observation point to be a strong red color as the blood flow velocity increases (the blood flow velocity increases). Then, the color determination unit 63 sends information (coordinate information) indicating the position of each observation point in the three-dimensional space and information (color information) indicating the color determined for each observation point to the color allocation unit 65. Output.

(Step S07)
Further, when the observation points are set by the second to fourth setting methods, the interpolation unit 64 is based on the blood flow velocity at each observation point, and the range (interpolation range) between the observation points adjacent to each other along the blood vessel. The blood flow velocity at is determined by interpolation. Then, the color determination unit 63 determines a color for the interpolation range according to the blood flow velocity in the interpolation range obtained by the interpolation unit 64. Then, the color determination unit 63 outputs information (coordinate information) indicating the position of the interpolation range in the three-dimensional space and information (color information) indicating the color determined for the interpolation range to the color allocation unit 65. To do.

(Step S08)
The color assigning unit 65 assigns the color determined by the color determining unit 63 to each observation point of the volume data representing the blood vessel form. Further, when the observation point is set by the second to fourth setting methods, the color assignment unit 65 determines the color of the interpolation range determined by the color determination unit 63 with respect to the interpolation range of the volume data representing the blood vessel form. Assign. Then, the color assignment unit 65 outputs volume data (color volume data) to which a color corresponding to the blood flow velocity is assigned to the three-dimensional image generation unit 66.

(Step S09)
The three-dimensional image generation unit 66 generates three-dimensional image data that three-dimensionally represents blood vessels by performing volume rendering on the color volume data.

(Step S10)
The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data generated by the 3D image generation unit 66. For example, as shown in FIG. 4, a three-dimensional image 20 in which a blood vessel is three-dimensionally displayed and a color corresponding to the blood flow velocity is assigned to each unit is displayed on the display unit 81. By observing the three-dimensional image 20 displayed on the display unit 81, the operator can grasp the three-dimensional shape of the blood vessel and the blood flow velocity in each part of the blood vessel at a time. That is, it is possible to clearly grasp the position of the blood vessel in the three-dimensional space and the speed of the blood flow flowing through the blood vessel. For example, by observing the three-dimensional image 20, the operator can clearly identify the location where the vascular stenosis has occurred.

(Ultrasonic image processing device)
In addition, an ultrasonic image processing apparatus that assigns a color corresponding to the magnitude of the blood flow velocity to volume data representing a blood vessel form may be provided outside the ultrasonic diagnostic apparatus. This ultrasonic image processing apparatus includes the above-described data storage unit 5, image processing unit 6, display control unit 7, and user interface (UI) 8. Then, the ultrasonic image processing apparatus assigns a color corresponding to the magnitude of the blood flow velocity to the volume data representing the blood vessel based on the volume data stored in the data storage unit 5 and the blood flow velocity.

  Specifically, the extraction unit 61 reads volume data from the data storage unit 5 and extracts volume data representing a blood vessel form from the volume data. The color determination unit 63 reads the blood flow velocity at each observation point from the data storage unit 5 and determines the color to be assigned to each observation point according to the magnitude of the blood flow velocity. Then, the color assignment unit 65 generates color volume data by assigning the color determined by the color determination unit 63 to the volume data representing the blood vessel shape extracted by the extraction unit 61. The three-dimensional image generation unit 66 generates three-dimensional image data by performing volume rendering on the color volume data. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data.

[Modification]
Next, a modification of the above-described embodiment will be described with reference to FIGS. FIG. 12 is a block diagram illustrating an ultrasonic diagnostic apparatus according to a modification. FIG. 13 is a schematic diagram for explaining a matching process of a plurality of three-dimensional image data.

  The ultrasonic diagnostic apparatus 1A according to the modification includes an ultrasonic probe 2, a transmission / reception unit 3, a signal processing unit 4, a data storage unit 5, an image processing unit 6A, a display control unit 7, a user interface (UI) 8, and a control unit. 9 is provided. In this modification, an image processing unit 6A is provided instead of the image processing unit 6 of the above-described embodiment. The image processing unit 6A includes an extraction unit 61, a color arrangement unit 62A, and a three-dimensional image generation unit 66. In this modification, a color arrangement unit 62A is provided instead of the color arrangement unit 62 described above. Since the configuration other than the color arrangement unit 62A is the same as the configuration of the ultrasonic diagnostic apparatus 1 according to the above-described embodiment, the configuration of the color arrangement unit 62A will be described, and the description of the configuration other than the color arrangement unit 62A will be omitted. The color arrangement unit 62A includes a color determination unit 63, an interpolation unit 64, a color allocation unit 65, a matching unit 67, and a flow velocity determination unit 68.

  In this modification, volume data in different directions is acquired by transmitting ultrasonic waves from a plurality of directions to the subject. For example, as shown in FIG. 13, by transmitting ultrasonic waves from the A direction, the B direction, and the C direction to the subject 200, the volume data in the A direction, the volume data in the B direction, and the C direction. Get volume data for. In the example shown in FIG. 13, the A direction, the B direction, and the C direction are orthogonal to each other. Accordingly, the volume data in the A direction, the volume data in the B direction, and the volume data in the C direction are volume data acquired from directions orthogonal to each other.

  Note that the example shown in FIG. 13 is one example. In this modification, ultrasonic waves may be transmitted from each of two or more directions to obtain volume data in each direction. In addition, the plurality of directions in which the ultrasonic waves are transmitted need not be orthogonal to each other.

  Specifically, the ultrasonic probe 2 is contacted to the subject 200 in the A direction, and the subject 200 is scanned with ultrasonic waves by the ultrasonic probe 2 and the transmission / reception unit 3 in this state. To get. The volume data in the A direction is stored in the data storage unit 5.

  Similar to the above-described embodiment, the extraction unit 61 extracts volume data representing the blood vessel form from the volume data in the A direction. Then, the extraction unit 61 outputs volume data representing the blood vessel form to the color assignment unit 65 and outputs information (coordinate information) indicating the position of the blood vessel in the three-dimensional space to the control unit 9.

  The observation point setting unit 91 sets a plurality of observation points along the blood vessel in the three-dimensional space according to any one of the first to fourth setting methods as in the above-described embodiment. Then, the control unit 9 outputs coordinate information of each observation point in the three-dimensional space to the transmission / reception unit 3.

  Then, in a state where the ultrasonic probe 2 is directed in the A direction shown in FIG. 13, the transmission / reception unit 3 performs each Doppler scan by the pulse Doppler method according to the coordinate information of the observation point set by the control unit 9. The Doppler information (blood flow information) of the point is acquired. The Doppler processing unit 42 obtains the blood flow velocity at each observation point based on Doppler information (blood flow information) at each observation point. Then, the Doppler processing unit 42 outputs coordinate information indicating the position of each observation point in the three-dimensional space and the blood flow velocity at each observation point to the color arrangement unit 62.

  The color determination unit 63 determines the color for each observation point according to the magnitude of the blood flow velocity at each observation point, as in the above-described embodiment. The color assigning unit 65 assigns the color determined by the color determining unit 63 to the volume data representing the blood vessel shape acquired from the A direction. As a result, a color corresponding to the magnitude of the blood flow velocity at each observation point acquired from the A direction is assigned to the volume data representing the blood vessel shape acquired from the A direction. For example, the color volume data 100 shown in FIG. 13 is color volume data acquired from the A direction. The color volume data 100 is assigned a color according to the blood flow velocity at each observation point acquired from the A direction. Then, the color allocation unit 65 outputs the color volume data 100 acquired from the A direction to the matching unit 67. Further, the color allocation unit 65 outputs the color volume data 100 to a data storage unit (not shown), and the data storage unit stores the color volume data 100.

  For the B direction and the C direction, similarly to the A direction, the color volume data acquired from the B direction and the color volume data acquired from the C direction are generated. For example, as illustrated in FIG. 13, the color volume data 100 acquired from the A direction, the color volume data 110 acquired from the B direction, and the color volume data 120 acquired from the C direction are output to the matching unit 67. The color volume data 110 and 120 are stored in a data storage unit (not shown).

  The matching unit 67 receives the plurality of color volume data from the color assignment unit 65 and performs pattern matching of the plurality of color volume data, thereby determining the position of the blood vessel form represented in each of the plurality of color volume data. Match. For example, the matching unit 67 performs pattern matching of the color volume data 100, 110, and 120 acquired from the A direction, and thereby the position of the blood vessel form represented in the color volume data 100 acquired from the A direction. The position of the blood vessel form represented in the color volume data 110 acquired from the B direction is matched with the position of the blood vessel form represented in the color volume data 120 obtained from the C direction.

  The flow velocity determination unit 68 compares the blood flow velocity values at the same part of the blood vessel in each color volume data based on the plurality of color volume data whose positions are matched by the matching unit 67, and the blood flow velocity at each part of the blood vessel. To decide.

  For example, when the blood flow velocity at the same location of the blood vessel is 0 m / sec in all color volume data, the flow velocity determination unit 68 determines the blood flow velocity at that location as 0 m / sec. If the blood flow velocity is 0 m / sec in all the color volume data, there is a high possibility that blood vessel stenosis has occurred at that location, so the flow velocity determination unit 68 sets the blood flow velocity at that location to 0 m / sec. decide.

  On the other hand, in one color volume data among a plurality of color volume data, the blood flow velocity at the same location of the blood vessel is 0 m / sec, and in another color volume data, the blood flow velocity at that location is xm / sec. When (x> 0), the flow velocity determination unit 68 determines the blood flow velocity at that location to xm / sec. In this case, since there is a possibility that an ultrasonic beam is transmitted from a direction orthogonal to the blood vessel at a location where the blood flow velocity is 0 m / sec, there is a possibility that blood vessel stenosis actually occurs at that location. Low. That is, since the blood flow velocity acquired from another direction is xm / sec (x> 0), the blood flow velocity is 0 m / sec from the direction orthogonal to the blood vessel. Is likely due to having been sent. Therefore, since there is a low possibility that a blood vessel stenosis has occurred at that location, the flow velocity determination unit 68 determines the blood flow velocity at that location as xm / sec. That is, when the blood flow velocity at the same location of the blood vessel is a value other than 0 m / sec in at least one color volume data among the plurality of color volume data, the flow velocity determination unit 68 determines the blood flow velocity at that location as the value. To decide.

  In all the color volume data, even if the blood flow velocity at the same portion of the blood vessel is not 0 m / sec, if the blood flow velocity is less than a predetermined velocity that can be regarded as blood vessel stenosis, the flow velocity determination unit 68 The blood flow velocity at may be determined to a value less than the predetermined velocity. For example, when the blood flow velocity at the same portion of the blood vessel is less than a predetermined blood flow velocity set in advance in all color volume data, the flow velocity determination unit 68 sets the blood flow velocity at that portion to the predetermined blood flow velocity. Determine blood flow velocity below the value. This predetermined value is a threshold value for determining whether or not vascular stenosis has occurred. If the blood flow velocity is less than this predetermined value in all color volume data, there is a possibility that blood vessel stenosis has occurred at that location.

  On the other hand, in at least one color volume data among a plurality of color volume data, when the blood flow velocity at the same portion of the blood vessel is a blood flow velocity equal to or higher than the predetermined value, the blood flow velocity at that location is equal to or higher than the predetermined value. Determine the blood flow velocity. In this case, at a location where the blood flow velocity is less than the predetermined value, an ultrasonic beam may be transmitted from a direction substantially orthogonal to the blood vessel, so that a blood vessel stenosis may actually occur at that location. The nature is low. Therefore, the flow velocity determination unit 68 determines the blood flow velocity at that location to be a blood flow velocity equal to or greater than a predetermined value.

  Further, in all the color volume data, when the blood flow velocities in the same part of the blood vessel are different values (> 0), the flow velocity determination unit 68 obtains an average value of the plurality of blood flow velocities, and the average The value may be determined as the blood flow velocity at that location.

  Then, the flow velocity determining unit 68 outputs coordinate information indicating the position of each part of the blood vessel in the three-dimensional space and the blood flow velocity in each part of the blood vessel to the color determining unit 63. The color determining unit 63 determines the color for each part of the blood vessel according to the magnitude of the blood flow velocity determined by the flow velocity determining unit 68.

  The color assigning unit 65 assigns a color to each part of the volume data representing the blood vessel shape according to the color determined by the color determining unit 63. At this time, the color assigning unit 65 assigns a color to any one of the plurality of volume data to be processed. Alternatively, the color assigning unit 65 may generate blood vessel volume data having an average form based on a plurality of volume data, and assign a color to each part of the volume data. Then, the color assignment unit 65 outputs the volume data (color volume data) to which the color is assigned to the three-dimensional image generation unit 66. The three-dimensional image generation unit 66 performs volume rendering on the color volume data, thereby generating three-dimensional image data in which a color corresponding to the blood flow velocity is assigned to each part of the blood vessel. Then, the display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data.

  As described above, by determining the blood flow velocity of each part of the blood vessel based on the volume data and blood flow velocity obtained from multiple directions, more accurate blood flow velocity is obtained, and according to the blood flow velocity It is possible to assign the displayed color to the three-dimensional image and display it. For example, depending on the transmission / reception direction of the ultrasonic beam, the ultrasonic beam is transmitted from a direction orthogonal to the blood vessel, and it is difficult to measure an accurate blood flow velocity at that point. In particular, at a location where the transmission / reception direction of the ultrasonic beam and the direction in which the blood vessel travels are orthogonal, the blood flow velocity becomes 0 m / sec even though no blood vessel stenosis has occurred. On the other hand, according to this modification, the blood flow velocity of each part of the blood vessel can be obtained based on the volume data and blood flow velocity acquired from a plurality of directions, so that the location where the blood vessel stenosis has occurred can be more accurately identified. It becomes possible to specify. As a result, the operator can accurately determine the presence or absence of vascular stenosis.

  An example will be described with reference to FIG. Based on the color volume data 100, 110, and 120 whose positions are matched by the matching unit 67, the flow velocity determination unit 68 compares the blood flow velocities at the same portion of the blood vessel in each of the color volume data 100, 110, and 120. Determine the blood flow velocity at each point.

  For example, in the color volume data 100 acquired from the A direction, a color corresponding to a slow blood flow velocity is assigned to the part 101 and the part 102. In the color volume data 110 acquired from the B direction, the color corresponding to the slow blood flow velocity is assigned to the site 111 and the site 112. Furthermore, in the color volume data 120 acquired from the C direction, a color corresponding to a slow blood flow velocity is assigned to the region 121. For example, a color corresponding to a blood flow velocity of 0 m / sec is assigned to the parts 101, 102, 111, 112, 121.

  The matching unit 67 aligns the color volume data 100, 110, 120. In the example illustrated in FIG. 13, the part 101, the part 111, and the part 121 are the same part. Since the blood flow velocity is 0 m / sec at these sites, the flow velocity determining unit 68 determines the blood flow velocity at that site to 0 m / sec. That is, in all the color volume data 100, 110, and 120, the blood flow velocity at that part is 0 m / sec, and thus there is a high possibility that blood vessel stenosis has actually occurred. Therefore, the flow velocity determination unit 68 determines the blood flow velocity at the site corresponding to the sites 101, 111, 121 to 0 m / sec.

  On the other hand, the blood flow velocity at the site 102 is 0 m / sec, but in the color volume data 110 and 120, the blood flow velocity at the location corresponding to the site 102 is xm / sec (x> 0). Therefore, the flow velocity determination unit 68 determines the blood flow velocity at that part to xm / sec. That is, in the color volume data 110 and 120, the blood flow velocity at the part corresponding to the part 102 is xm / sec, so that the possibility that a blood vessel stenosis has occurred at that part is low. In the region 102, it is highly likely that an ultrasonic beam is transmitted from a direction orthogonal to the blood vessel. Therefore, the flow velocity determination unit 68 determines the blood flow velocity at the part corresponding to the part 102 to xm / sec.

  Similarly, the blood flow velocity at the site 112 is 0 m / sec, but in the color volume data 100 and 120, the blood flow velocity at the location corresponding to the site 112 is xm / sec (x> 0). Therefore, the flow velocity determination unit 68 determines the blood flow velocity at that part to xm / sec.

  Then, the flow velocity determining unit 68 outputs coordinate information indicating the position of each part of the blood vessel in the three-dimensional space and the blood flow velocity in each part of the blood vessel to the color determining unit 63. The color determination unit 63 determines a color to be assigned to each part according to the blood flow velocity of each part of the blood vessel determined by the flow rate determination unit 68.

  The color assigning unit 65 assigns the color determined by the color determining unit 63 to each part of the volume data representing the blood vessel form. The color volume data 130 shown in FIG. 13 is volume data after colors are assigned by the color assigning unit 65. The part 131 is a part corresponding to the part 101, the part 111, and the part 121. The region 131 is assigned a color corresponding to a blood flow velocity of 0 m / sec.

  Note that the color assignment unit 65 includes volume data representing the form of blood vessels acquired from the A direction to be processed, volume data representing the form of blood vessels obtained from the B direction, and blood vessels obtained from the C direction. Color volume data 130 shown in FIG. 13 is generated by assigning the color determined by the color determination unit 63 to each part of any one of the volume data representing the above form. Alternatively, the color assigning unit 65 may display volume data representing a blood vessel shape acquired from the A direction, volume data representing a blood vessel shape obtained from the B direction, and volume data representing a blood vessel shape obtained from the C direction. The color volume data 130 may be generated by generating volume data of a blood vessel having an average form based on the above and assigning a color to each part of the volume data. Then, the color assignment unit 65 outputs the color volume data 130 to the three-dimensional image generation unit 66.

  The three-dimensional image generation unit 66 performs volume rendering on the color volume data 130 to generate three-dimensional image data in which a color corresponding to the magnitude of the blood flow velocity is assigned to each unit. The display control unit 7 causes the display unit 81 to display a 3D image based on the 3D image data. In the example illustrated in FIG. 13, a three-dimensional image based on the color volume data 130 is displayed on the display unit 81.

  In this modified example, as in the above-described embodiment, the interpolation unit 64 obtains the blood flow velocity in the interpolation range by interpolation. The angle correction unit 92 corrects the transmission / reception direction of the ultrasonic beam.

  Further, the image processing unit 6A includes a CPU and a storage device such as a ROM and a RAM. The storage device includes an extraction program for executing the function of the extraction unit 61, a color arrangement program for executing the function of the color arrangement unit 62A, and an image generation program for executing the function of the three-dimensional image generation unit 66. It is remembered. The color arrangement program includes a color determination program for executing the function of the color determination unit 63, an interpolation program for executing the function of the interpolation unit 64, a program for executing the function of the color allocation unit 65, and a matching unit. A matching program for executing the function 67 and a blood flow velocity determining program for executing the function of the flow velocity determining unit 68 are included.

  In this modified example, the CPU executes a matching program to align a plurality of color volume data. In addition, the CPU executes the blood flow velocity determination program to compare the blood flow velocity in each part of the plurality of color volume data in which the positions are matched, and determine the blood flow velocity in each part. .

(Marker display)
In the above-described embodiment or modification, a marker indicating vascular stenosis may be displayed at a location where the blood flow velocity is 0 m / sec. For example, the three-dimensional image generation unit 66 outputs the three-dimensional image data to the display control unit 7 and controls the display of the coordinate information of the portion to which the color corresponding to 0 m / sec is assigned in the three-dimensional image data. Output to unit 7. The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data, and further superimposes a marker indicating vascular stenosis on the three-dimensional image on the display unit 81 at the location indicated by the coordinate information. Display. The shape of the marker may be circular or rectangular. In this way, by displaying the marker at the location where the blood flow velocity is 0 m / sec, the operator can easily identify the location where the vascular stenosis has occurred.

  Even if the blood flow velocity is not 0 m / sec, a marker may be displayed at a location where the blood flow velocity is less than a velocity that can be regarded as vascular stenosis. For example, the three-dimensional image generation unit 66 outputs the three-dimensional image data to the display control unit 7, and in the three-dimensional image data, coordinates of a location to which a color corresponding to a blood flow velocity less than a predetermined value is assigned. Information is output to the display control unit 7. This predetermined value is a threshold value for determining whether or not vascular stenosis has occurred. If the blood flow velocity is less than this predetermined value, there is a possibility that vascular stenosis has occurred at that location. The display control unit 7 causes the display unit 81 to display a three-dimensional image based on the three-dimensional image data, and further superimposes a marker indicating vascular stenosis on the three-dimensional image on the display unit 81 at the location indicated by the coordinate information. Display. As a result, the operator can easily identify a portion where there is a risk of blood vessel stenosis.

1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a figure which shows typically the volume data showing the form of the blood vessel. It is a schematic diagram which shows the 1st setting method of the observation point (sample position) with respect to the blood vessel. It is a figure which shows an example of the three-dimensional image produced | generated by the ultrasound diagnosing device which concerns on embodiment of this invention. It is a schematic diagram which shows the 2nd setting method of the observation point (sample position) with respect to the blood vessel. It is a figure for demonstrating the interpolation method between observation points (sample position). It is a schematic diagram which shows the 3rd setting method of the observation point (sample position) with respect to the blood vessel. It is a schematic diagram which shows the 4th setting method of the observation point (sample position) with respect to the blood vessel. It is a schematic diagram of a blood vessel for explaining angle correction of an ultrasonic beam. It is a figure which shows the three-dimensional image corresponding to a cardiac time phase. It is a flowchart which shows a series of operation | movement by the ultrasound diagnosing device which concerns on embodiment of this invention. It is a block diagram which shows the ultrasonic diagnosing device which concerns on a modification. It is a schematic diagram for demonstrating the matching process of several three-dimensional image data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ultrasonic diagnostic apparatus 2 Ultrasonic probe 3 Transmission / reception part 4 Signal processing part 5 Data storage part 6, 6A Image processing part 7 Display control part 8 User interface (UI)
DESCRIPTION OF SYMBOLS 9 Control part 41 B mode process part 42 Doppler process part 61 Extraction part 62, 62A Color arrangement part 63 Color determination part 64 Interpolation part 65 Color allocation part 66 Three-dimensional image generation part 67 Matching part 68 Flow velocity determination part 81 Display part 82 Operation part 91 Observation point setting unit 92 Angle correction unit

Claims (12)

Image acquisition means for transmitting ultrasonic waves to the subject and acquiring volume data of the subject;
Extraction means for extracting volume data representing the morphology of blood vessels from the volume data of the subject;
Observation point setting means for setting an observation point along the blood vessel in the three-dimensional region based on the volume data representing the extracted blood vessel shape;
Flow velocity acquisition for acquiring the flow velocity of a moving body at a location where the observation point of the blood vessel is set by transmitting an ultrasonic wave to a position indicated by each observation point set in the three-dimensional region and executing a Doppler scan Means,
A color volume data in which a color is assigned to each location is generated by assigning a color corresponding to the magnitude of the acquired flow velocity to a location where the observation point is set in the volume data representing the shape of the blood vessel. Color arrangement means;
Display control means for displaying on the display means an image based on the color volume data;
An ultrasonic diagnostic apparatus comprising:   The said flow velocity acquisition means performs a pulse Doppler scan as said Doppler scan, and acquires the flow velocity of the said moving body by performing a FFT process on the signal acquired by the said pulse Doppler scan. Ultrasonic diagnostic equipment.   The ultrasonic diagnostic apparatus according to claim 1, wherein the observation point setting unit sets the observation points at predetermined intervals along the blood vessel in the three-dimensional region. .   The color arrangement means obtains the flow velocity between the adjacent observation points by interpolation based on the flow velocity acquired at the adjacent observation points along the blood vessel, and the observation point in the volume data representing the blood vessel is set. In addition, a color corresponding to the magnitude of the flow velocity acquired at the observation point is assigned to each spot, and further, between the observation points adjacent along the blood vessel, the magnitude of the flow velocity obtained by the interpolation is assigned. The ultrasonic diagnostic apparatus according to claim 3, wherein a corresponding color is assigned.   The observation point setting means sets a plurality of observation points by overlapping a part of the observation points having a predetermined size on adjacent observation points along the blood vessel in the three-dimensional region. The ultrasonic diagnostic apparatus according to claim 1.   The observation point setting means overlaps a part of the observation point having a predetermined size with an adjacent observation point for a portion included in a predetermined region of interest among the blood vessels in the three-dimensional region. The ultrasonic diagnostic apparatus according to claim 1, wherein a plurality of observation points are set, and the observation points are set at predetermined intervals for portions that are not included in the region of interest.   The observation point setting means identifies a location where the blood vessel branches based on the volume data representing the extracted blood vessel morphology, and a predetermined range including the branch location has a predetermined size. 2. A plurality of observation points are set by overlapping a part of observation points on adjacent observation points, and the observation points are set at predetermined intervals for a range other than the predetermined range. Ultrasound diagnostic equipment. The observation point setting means specifies an observation point in which the blood vessel in the three-dimensional region and the ultrasonic wave transmission / reception direction are substantially orthogonal among the set observation points,
The said flow velocity acquisition means transmits an ultrasonic wave from directions other than the orthogonal direction with respect to the specified observation point, The Doppler scan is performed, It is any one of Claim 1-7 characterized by the above-mentioned. An ultrasonic diagnostic apparatus according to 1. The flow velocity acquisition means sets the observation point of the blood vessel by transmitting an ultrasonic wave at different times to the position indicated by the observation point set in the three-dimensional region and executing a Doppler scan. Obtaining the flow velocity of the moving body at a location at each different time,
The color arrangement means assigns a color according to the magnitude of the flow velocity acquired at each time to a place where the observation point is set in the volume data representing the blood vessel form, so that the different color for each different time. The ultrasonic diagnostic apparatus according to claim 1, wherein the color volume data is generated. Storage means for storing a plurality of color volume data acquired by transmitting ultrasonic waves from different directions to the subject;
Matching means for matching the position of the blood vessel form represented in each of the plurality of color volume data by performing pattern matching of the plurality of color volume data stored in the storage means;
Based on the flow velocity of each moving body acquired by the flow velocity acquisition means at the same location of each of the plurality of color volume data in which the positions are matched, the flow velocity determination means for obtaining the flow velocity at the same location;
Further comprising
The ultrasonic diagnosis according to any one of claims 1 to 8, wherein the color arrangement unit assigns the color determined by the flow velocity determination unit to each location of the volume data representing the form of the blood vessel. apparatus.   When the flow velocity of the moving body at the same location is 0 m / sec in all the color volume data, the flow velocity determination means determines the flow velocity at that location as 0 m / sec, and the plurality of color volumes The at least one color volume data among the data, when the flow velocity of the moving body at the same location is a value other than 0 m / sec, the flow velocity at that location is determined as the value. Ultrasound diagnostic equipment. On the computer,
An extraction function for receiving volume data of the subject obtained by transmitting ultrasonic waves to the subject, and extracting volume data representing a blood vessel form from the volume data of the subject;
By accepting the flow velocity of the moving body acquired in each part of the blood vessel in the three-dimensional space and assigning a color corresponding to the magnitude of the flow velocity in each part to each part of the volume data representing the form of the blood vessel, A color arrangement function for generating color volume data to which colors are assigned;
A display control function for causing the display device to display an image based on the color volume data;
An ultrasonic image processing program characterized in that is executed.