JP7426086B2 - Ultrasonic blood flow region display device, method and program, ultrasonic image diagnostic device - Google Patents

Description

The present invention relates to an apparatus, method, and program for imaging and displaying a blood flow region using ultrasound, and an ultrasound image diagnostic apparatus.

2. Description of the Related Art Conventionally, an ultrasonic image diagnostic apparatus is well known as a simple and highly safe diagnostic apparatus for imaging the inside of a subject. In an ultrasonic image diagnostic apparatus, a tomographic image is usually generated by B-mode processing of signals obtained by transmitting and receiving ultrasonic waves, and the tomographic image is displayed on a display device. In addition, in this type of device, it has been proposed in the past to generate a blood flow image by Doppler analysis of signals obtained by transmitting and receiving ultrasound waves, and to display the blood flow image superimposed on a tomographic image (for example, Patent Document 1).

According to such blood flow imaging using the Doppler method, it is possible to understand the blood flow distribution of the target site or tissue, and by extension, the activation and degeneration state of the target site or tissue. becomes possible. Therefore, this method is considered to be effective not only for observing the state of injured areas and malignant neoplasms and observing the progress of healing, but also for observing tissues around tissues such as follicles and corpus luteum (for example, for pregnancy tests).

Japanese Patent Application Publication No. 2014-121594

However, new blood vessels around the target site or target tissue are a collection of microvessels (vascular network), and thus have a lower blood flow than larger blood vessels. Therefore, it has been difficult to detect blood flow, and it has been difficult to quantitatively evaluate blood flow distribution using blood flow area, etc.

When determining the blood flow area, the worker visually checks the blood vessel image on the screen of the display device and manually traces the area that he or she recognizes as the blood flow area to specify the blood flow area. I usually do the work that I do. However, although the task of specifying large blood vessels is not so difficult, the task of specifying a vascular network including small blood vessels is extremely difficult and complicated.

In other words, even if you visually inspect a blood vessel image, it is difficult to tell where the boundary is between areas with blood flow and areas without blood flow, and it is difficult to determine at what level the appropriate signal intensity threshold should be set to specify the blood vessel network. Difficult to judge. Therefore, it is almost impossible to trace and accurately specify the entire vascular network, which is one reason why it is difficult to quantitatively evaluate the blood flow distribution of microvessels.

The present invention has been made in view of the above-mentioned problems, and its purpose is to enable the operator to relatively easily specify the range recognized as the blood flow area of the vascular network, and to improve the blood flow distribution. An object of the present invention is to provide a device, method, and program that can facilitate quantitative evaluation, and an ultrasonic image diagnostic device.

In order to solve the above problem, the invention according to claim 1 includes a B-mode data generation unit that generates tomographic image data by performing B-mode processing on signals obtained by transmitting and receiving ultrasound to and from a subject; By converting blood flow information obtained by Doppler analysis of the signal into color information based on a color index that corresponds to a display color whose hue changes continuously and the signal intensity of the signal, a blood flow image is generated. an image processing unit that generates image display data in which the blood flow image is superimposed on the tomographic image; signal strength designating means for designating the signal strength near the boundary of the signal strength; and a signal strength designating means for designating the signal strength near the boundary of display color replacement means for replacing the blood flow with a specific display color that is not displayed, and the blood flow mapping data generation unit replaces the blood flow image with the blood flow region surrounded by the replaced specific display color. The gist of the present invention is an ultrasonic blood flow region display device characterized by generating data.

Therefore, according to the invention described in claim 1, it is possible to specify that a location corresponding to the signal intensity near the boundary between a blood flow region and a non-blood flow region is not continuous in hue with the surrounding display color on the color index. will be replaced with the display color. Therefore, in the blood flow image, the blood flow region is displayed surrounded by a visually easy-to-understand color outline. Therefore, the boundary between the blood flow region and the non-blood flow region becomes easy to understand, and it becomes possible to easily determine at what level a signal intensity threshold appropriate for specifying a vascular network should be set. Therefore, it is possible to relatively easily specify the range that the operator himself/herself recognizes as the blood flow region of the vascular network, making it easier to quantitatively evaluate the blood flow distribution.

The gist of the invention according to claim 2 is that in claim 1, the apparatus further includes signal strength adjustment means for adjusting the value of the signal strength designated by the signal strength designation means.

Therefore, according to the invention recited in claim 2, since it is possible to adjust the value of the specified signal intensity, it is possible to set the threshold level more appropriately, and as a result, it is possible to more easily determine the blood flow area of the vascular network. This makes it possible to specify information accurately and accurately.

According to a third aspect of the invention, in the first or second aspect, the image display data includes the blood flow image and the display color corresponding to the designated signal intensity replaced with the specific display color. The gist thereof is that the tomographic image is obtained by superimposing the image of the color index of .

Therefore, according to the third aspect of the invention, in addition to the blood flow image, the color index image is displayed superimposed on the tomographic image. As a result, it becomes easier to intuitively understand where the replaced specific display color is located in the color index (that is, what the specified threshold level is).

In the invention according to claim 4, in any one of claims 1 to 3, the display color that continuously changes in the color index is a warm color, and the specific display color is a cool color. Its gist is that it is a color.

The invention according to claim 5 includes a B-mode data generation step of generating tomographic image data by performing B-mode processing on signals obtained by transmitting and receiving ultrasonic waves to and from a subject; and a B-mode data generation step of generating tomographic image data by performing Doppler analysis on the signals. a blood flow mapping data generation step of generating blood flow mapping data based on the blood flow information obtained; and a signal strength specification step of specifying the signal strength near the boundary between the blood flow region and the non-blood flow region. On a color index in which a display color whose hue changes corresponds to the signal strength of the signal, the display color corresponding to the designated signal strength is hue-wise compared to the surrounding display colors on the color index. a display color replacement step of replacing the blood flow with a specific non-continuous display color; and converting the blood flow mapping data into color information with reference to the color index; Abstract: An ultrasonic blood flow region display method including an image processing step of generating blood flow image data in a state in which the region is surrounded, and generating image display data in which the blood flow image is superimposed on the tomographic image. shall be.

The invention according to claim 6 includes a B-mode data generation step of generating tomographic image data by subjecting the processor to B-mode processing of a signal obtained by transmitting and receiving ultrasound to and from a subject, and performing Doppler analysis on the signal. Blood flow image data is generated by converting the obtained blood flow information into color information based on a color index that associates a display color whose hue changes continuously with the signal intensity of the signal. a blood flow mapping data generation step, an image processing step of generating image display data in which the blood flow image is superimposed on the tomographic image, and the signal intensity near the boundary between the blood flow region and the non-blood flow region is specified. sometimes, display color replacement for replacing the display color on the color index corresponding to the designated signal strength with a specific display color that is not continuous in hue with surrounding display colors on the color index; The gist of the present invention is an ultrasonic blood flow region display program for executing steps.

The gist of the invention set forth in claim 7 is an ultrasonic image diagnostic apparatus equipped with a storage means storing the program set forth in claim 6.

As described in detail above, according to the inventions recited in claims 1 to 7, it is possible to relatively easily specify the range that the operator himself/herself recognizes as the blood flow area of the vascular network, and to control the blood flow distribution. It is possible to provide a device, a method, a program, and an ultrasonic image diagnostic device that can facilitate quantitative evaluation.

1 is a front view showing an ultrasonic image diagnostic apparatus according to an embodiment of the present invention; FIG. FIG. 2 is a block diagram showing the electrical configuration of the device. FIG. 3 is an enlarged view of a color index image displayed on a display screen (before display color replacement). 2 is a graph showing the relationship between blood flow and weighting coefficients in the filtering section of the device. 2 is a flowchart for explaining a series of processes in the device. 2 is a flowchart for explaining blood flow area calculation processing in the device. FIG. 3 is an enlarged view of a color index image (after display color replacement) displayed on a display screen. FIG. 7 is a diagram illustrating a display screen that displays a blood flow image in which a blood flow region is surrounded by a replaced specific display color. FIG. 7 is a diagram illustrating a display screen that displays a blood flow image in which a blood flow region is surrounded by a replaced specific display color. FIG. 7 is a diagram illustrating a display screen that displays a blood flow image in which a blood flow region is surrounded by a replaced specific display color. FIG. 7 is a diagram illustrating a display screen that displays a blood flow image in which a blood flow region is surrounded by a replaced specific display color.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultrasonic blood flow region display device of the present invention applied to an ultrasonic image diagnostic apparatus having blood flow region display and blood flow area calculation functions will be described in detail below with reference to the drawings. FIG. 1 is a front view showing an ultrasonic image diagnostic apparatus 11 of this embodiment, and FIG. 2 is a block diagram showing the electrical configuration of the ultrasonic image diagnostic apparatus 11.

As shown in FIGS. 1 and 2, this ultrasonic image diagnostic apparatus 11 includes an apparatus main body 12 and an ultrasonic probe 13 connected to the apparatus main body 12. The ultrasonic probe 13 includes a signal cable 14 , a probe head 15 connected to the tip of the signal cable 14 , and a probe-side connector 16 provided at the base end of the signal cable 14 . The apparatus main body 12 is provided with a main body side connector 17, and a probe side connector 16 of the ultrasound probe 13 is detachably connected to the main body side connector 17.

As shown in FIG. 2, the probe head 15 of the ultrasound probe 13 has a plurality of ultrasound transducers arranged in a fan shape. When using the ultrasound probe 13, the probe head 15 is brought into contact with the living tissue of the subject 19, and ultrasound is transmitted and received in this state. Although the type of the ultrasonic probe 13 is not particularly limited, the one in this embodiment is a convex probe for performing convex electronic scanning, and emits, for example, 5 MHz ultrasonic waves in a fan shape.

The device main body 12 includes a controller 21, a pulse generating circuit 22, a transmitting circuit 23, a receiving circuit 24, a signal processing section 25, a memory 26, a storage device 27, a display device 28, an input device 29, and the like.

The controller 21 includes a well-known central processing unit (CPU), executes a predetermined control program using the memory 26, and controls the entire device in an integrated manner. Note that this control program includes a program for calculating the blood flow area, etc.

The display device 28 is a color display such as a liquid crystal display, an organic EL display, a plasma display, a CRT display, or a projection display, and displays tomographic images of biological tissues and blood flow images, and input screens for various settings. It is used to do things.

The input device 29 includes, for example, a keyboard, switches, various pointing devices, and the like, and is used to input instructions and parameters from an operator. Note that examples of pointing devices include touch pads, touch panels, mice, pen tablets, trackballs, joysticks, and the like.

The storage device 27 is, for example, a magnetic disk device, an optical disk device, a semiconductor storage device, etc., and stores control programs and various data. The controller 21 transfers programs and data from the storage device 27 to the memory 26 according to instructions from the input device 29, and sequentially executes them. The program executed by the controller 21 may be a program stored in a storage medium such as a magnetic disk such as a flexible disk, an optical disk such as a CD, DVD, or BD, or a semiconductor memory such as a USB memory, flash memory, or SD card. , or a program downloaded via a communication medium. Such a program is installed in the storage device 27 before being executed.

The pulse generation circuit 22 operates in response to a control signal from the controller 21, and generates and outputs a pulse signal of a predetermined period.

The transmission circuit 23 includes a plurality of delay circuits (not shown) corresponding to the number of ultrasonic transducer elements in the ultrasonic probe 13. The transmitting circuit 23 outputs a driving pulse delayed according to each ultrasonic transducer based on the pulse signal output from the pulse generating circuit 22. The delay time of each drive pulse is set so that the ultrasonic waves output from the ultrasonic probe 13 are focused at a predetermined irradiation point.

The receiving circuit 24 includes a signal amplifying circuit, a delay circuit, and a phasing/summing circuit (not shown). In this receiving circuit 24, each reflected wave signal (echo signal) received by each ultrasonic transducer in the ultrasound probe 13 is amplified, and a delay time is added to each reflected wave signal in consideration of reception directivity. After that, phasing and addition are performed. By this addition, the phase difference between the received signals of each ultrasonic transducer is adjusted.

The signal processing section 25 of this embodiment includes a phase synthesis section 31, a B-mode data generation section 32, a blood flow mapping data generation section 33, an image processing section 34, and the like.

The phase synthesis unit 31 inputs each amplified reflected wave signal, adds a delay time that takes into account reception directivity to each reflected wave signal, and then performs phasing and addition. By this addition, the phase difference between the reflected wave signals received by each ultrasonic transducer is adjusted.

The B-mode data generation section 32 includes a logarithmic conversion circuit, an envelope detection circuit, an A/D conversion circuit, etc. (not shown). The B-mode data generation unit 32 performs a process of converting signal intensity into brightness (i.e., B-mode processing) based on the reflected wave signal whose phase difference has been adjusted, and generates B-mode data for obtaining a tomographic image. . The logarithmic conversion circuit logarithmically converts the reflected wave signal, and the envelope detection circuit detects the envelope of the output signal of the logarithmic conversion circuit. Further, the A/D conversion circuit converts the analog signal output from the envelope detection circuit into a digital signal.

The image processing unit 34 performs predetermined image processing based on the signal output from the B-mode data generation unit 32, and generates image data of a tomographic image (B-mode image). Specifically, the image processing unit 34 generates image display data of brightness according to the amplitude (signal strength) of the reflected wave signal. The image display data generated by the image processing section 34 is sequentially stored in the memory 26. Then, based on one frame of image display data stored in the memory 26, a tomographic image of the biological tissue is displayed on the display screen of the display device 28 in black and white shading. That is, the ultrasound image displayed in this embodiment is a monochrome image (monotone image).

The blood flow mapping data generation section 33 has a Doppler analysis section 41. This Doppler analysis unit 41 performs frequency analysis (Doppler analysis) by signal processing such as fast Fourier transform based on the reflected wave signal whose phase difference has been adjusted, thereby obtaining blood flow information (here, the signal amount of the Doppler component). (information about the power of the signal). Based on such blood flow information, the blood flow mapping data generation unit 33 generates blood flow mapping data for obtaining a blood flow image. Note that since the signal amount of the Doppler component is generally proportional to the amount of blood cells that are the reflection source in the blood vessel, a large signal amount of the Doppler component means that the blood flow is large.

The image processing unit 34 performs predetermined image processing based on the signal output from the blood flow mapping data generation unit 33 to generate image data of a blood flow image. More specifically, the image processing unit 34 refers to the color index 61 stored in the memory 26 and performs a process of converting blood flow mapping data into color information. The color index 61 consists of display colors 62 whose hues change continuously. This display color 62 has a corresponding relationship with the signal amount (signal intensity) of the Doppler component. Therefore, the image processing unit 34 performs a process of converting each pixel within the region of interest 48 (ROI) into a display color corresponding to the signal amount of the Doppler component for each pixel, and uses the converted image data as image data of a blood flow image. The image processing unit 34 is configured to generate image display data in which the blood flow image is superimposed on the tomographic image generated based on the B-mode data. The above image display data in which a blood flow image is superimposed on a tomographic image is also sequentially stored in the memory 26. Then, based on the image display data for one frame stored in the memory 26, a display image is displayed on the display device 28, in which blood flow images in different hues depending on the blood flow volume are superimposed on the black and white tomographic image. displayed on the display screen. At this time, the image of the color index 61 is similarly superimposed on the tomographic image and displayed on the display screen of the display device 28.

FIG. 3 shows an image of the color index 61 displayed on the display screen. In the image of the color index 61 of this embodiment, the hue is specified to change from black, dark red, red, red-orange, orange, yellow-orange, and yellow in descending order of blood flow. Therefore, for example, blood flow images when the blood flow is low are displayed from dark red to red, blood flow images when the blood flow is medium are displayed from red-orange to orange, and blood flow images when the blood flow is high are displayed from yellow-orange to yellow. ing. Note that the display device 28 of this embodiment is configured to be able to selectively display a display image in which a blood flow image is superimposed on a tomographic image, and a display image that is only a tomographic image without a blood flow image superimposed thereon. There is.

Next, a configuration for displaying a blood flow region and calculating a blood flow area in the ultrasound image diagnostic apparatus 11 of this embodiment will be described.

The blood flow mapping data generation section 33 of this ultrasound image diagnostic apparatus 11 includes, in addition to the above-mentioned Doppler analysis section 41, a filtering section 42 and a blood flow determination section 43 at the subsequent stage. The filtering unit 42 performs filtering by increasing the weighting coefficient when the blood flow changes in an increasing direction, and decreasing the weighting coefficient when the blood flow changes in a decreasing direction.

To explain this specifically, the filtering section 42 processes the Doppler signal from the Doppler analysis section 41 using a predetermined weighting coefficient (α; a number larger than 0 and smaller than 1). It is a digital filter. The input digital data of the Doppler signal is filtered by a predetermined weighting coefficient α set in advance in the multiplier (here, after being multiplied by α), and then output to the adder. The delay element holds the digital data of the Doppler signal that was filtered one time earlier, and the data thus delayed and buffered is fed back to the adder. Then, in the adder, the digital data of the latest Doppler signal and the digital data of the immediately preceding Doppler signal (after filtering processing) are added at a predetermined ratio. Then, the result of this addition, that is, the filtered Doppler signal, is output to the image processing section 34 and the blood flow determining section 43.

Here, the digital data of the latest Doppler signal is expressed as "Input(n)", and the digital data of the immediately preceding Doppler signal (after filtering processing) is expressed as "Output(n-1)". Then, the digital data of the latest Doppler signal multiplied by the weighting coefficient α is "α・Input(n)", and the digital data of the immediately preceding Doppler signal multiplied by 1-α is "(1- α)・Output(n-1)", the digital data of the Doppler signal after the filtering process, which is the addition result, "Output(n)" is as shown in the following equation 1.

Output(n) = α・Input(n) + (1-α)・Output(n-1) ・・・(1)

By the way, in this embodiment, the weighting coefficient α is not always constant, but is set so that it takes a large value α1 when the blood flow changes in the increasing direction and takes a small value α2 when the blood flow changes in the decreasing direction. A control unit switches the weighting coefficient α. Note that the relationship 1>α1>α2>0 holds between these two large and small weighting coefficients. Note that FIG. 4 shows a graph for explaining this. In the graph, a curve C1 shows the relationship between blood flow and weighting coefficients.

Here, consider the value obtained by subtracting the absolute value of the digital data "Output(n-1)" of the immediately preceding Doppler signal from the absolute value of the digital data "Input(n)" of the latest Doppler signal. When this subtraction value is greater than or equal to δa (δa is a predetermined blood flow threshold), that is, when the blood flow changes in the direction of increasing, the weighting coefficient α1, which is close to 1, is used as the weighting coefficient in Equation 1 above. Applicable. Therefore, in this case, the digital data "Output(n)" of the Doppler signal after filtering processing is the digital data "Input(n)" of the latest Doppler signal, which is the data with higher blood flow, as shown in the following equation 2. The contribution rate of

Output(n) = α1・Input(n) + (1-α1)・Output(n-1) ・・・(2)

On the other hand, when the above-mentioned subtraction value is less than δa, that is, when the blood flow rate changes in a decreasing direction, a weighting coefficient α2 having a value close to 0 is applied as the weighting coefficient in the above equation 1. Therefore, in this case, the digital data "Output(n)" of the Doppler signal after the filtering process is calculated as shown in the following equation 3. )" contribution rate increases.

Output(n) = α2・Input(n) + (1-α2)・Output(n-1) ・・・(3)

The blood flow determination unit 43 determines whether or not there is blood flow within the region of interest (ROI) 48 after filtering using a predetermined threshold value δb. In making this determination, the threshold value δb is determined in advance by the controller 21, which serves as a signal strength specifying means and a display color replacing means.

Control programs for specifying signal strength and replacing display colors are stored in the memory 26, and the controller 21 executes predetermined processing according to these control programs. The controller 21 serving as a signal intensity designation means designates the signal strength near the boundary between the blood flow region R1 and the non-blood flow region R2 when an operator gives an instruction via the input device 29. Furthermore, the controller 21 as display color replacement means replaces the display color 62 on the color index 61 corresponding to the designated signal strength with a specific display color that is not continuous in hue with the surrounding display colors 62 on the color index 61. Replace with color 63. For example, in this embodiment, since the continuously changing display color 62 in the color index 61 is a warm color, a cool color (here, blue) is used as the specific display color 63. When the display color 62 is replaced in this way, the blood flow mapping data generation unit 33 generates blood flow image data in which the blood flow region R1 is surrounded by the replaced specific display color 63. (See Figure 1). Therefore, in this embodiment, a blood flow image in which the blood flow region R1 is surrounded by the blue outline L1 is displayed on the display screen of the display device 28. The operator visually checks this display screen, adjusts the value of the signal intensity as appropriate, and designates the range that he or she recognizes as the blood flow region R1 of the vascular network M1, and the threshold value δb is determined based on this.

The blood flow determining unit 43 uses the threshold value δb determined as described above to compare the magnitude with the absolute value of the Doppler signal "Input(n)" after the filtering process. If the absolute value of the Doppler signal “Input(n)” after filtering processing is greater than or equal to δb, the blood flow determining unit 43 determines that “blood flow exists” and outputs “1” as the output signal Output(n) to the image processing unit. 34 and a pixel number counting section 44. On the other hand, if the absolute value is less than δb, the blood flow determination unit 43 determines that there is “no blood flow” and outputs “0” as the output signal Output(n) to the image processing unit 34 and the pixel number counting unit 44. .

Further, the signal processing section 25 of this embodiment further includes a pixel number counting section 44 and a blood flow area calculating section 45 . The pixel number counting unit 44 counts the number of pixels indicating blood flow within the region of interest 48 when it is determined that there is blood flow within the region of interest 48 . Specifically, when the pixel number counting unit 44 receives the output signal Output(n) of “1” from the blood flow determination unit 43, the total number of pixels is calculated by integrating the numbers. .

The blood flow area calculation unit 45 calculates and quantifies the blood flow area by multiplying the ratio of the number of pixels indicating blood flow to the total number of pixels in the region of interest 48 by the area of the region of interest 48. This blood flow area calculation data is sequentially stored in the memory 26, and is displayed in numbers as a blood flow area value on the display screen of the display device 28, if necessary. In this embodiment, a blood flow area value display area 51 is provided at the lower right side of the display screen, and the blood flow area value is displayed there as, for example, "〇〇〇mm2. ^"

Next, the diagnostic processing in the ultrasound image diagnostic apparatus 11 of this embodiment will be explained using the flowcharts of FIGS. 5 and 6. The process in FIG. 5 is started when an operator (for example, a veterinarian) brings the ultrasound probe 13 into contact with the subject 19 and operates a start switch provided on the input device 29. Here, since the ultrasound image diagnostic apparatus 11 is used for pregnancy testing of livestock, the subject 19 is a living tissue including parts such as follicles and corpus luteum in the livestock. Incidentally, when a follicle, corpus luteum, etc. start developing in the early stages of pregnancy, a vascular network M1 consisting of microvessels is generated around the site. Therefore, if the blood flow area around the region is larger than a predetermined value, it can be determined that the livestock is pregnant.

First, the controller 21 sends a message to the display device 28 prompting for the input of management information such as livestock identification number, age, diagnosis date and time, and setting information such as image display direction and display range, as information related to ultrasonic diagnosis. Display on the input screen. Here, the operator operates the keyboard, trackball, etc. of the input device 29 to input various information (step S100). The controller 21 takes in the information and temporarily stores it in the memory 26.

After inputting various information is completed, the controller 21 operates the pulse generation circuit 22 and causes the ultrasound probe 13 to start transmitting and receiving ultrasound (step S110). Specifically, the pulse generation circuit 22 operates in response to a control signal output from the controller 21, and a pulse signal of a predetermined period is supplied to the transmission circuit 23. Then, in the transmission circuit 23, a drive pulse having a delay time corresponding to each ultrasound transducer is generated based on the pulse signal, and is supplied to the ultrasound probe 13. As a result, each ultrasonic transducer of the ultrasonic probe 13 vibrates, and ultrasonic waves are irradiated toward the living tissue. A portion of the ultrasound waves propagating within the living tissue is reflected by tissue interfaces with different acoustic impedances and received by the ultrasound probe 13 . At this time, each ultrasonic transducer of the ultrasonic probe 13 converts the reflected waves into electrical signals (reflected wave signals). Then, the reflected wave signal is amplified by the receiving circuit 24 and then output to the signal processing section 25.

In the following step S120, the controller 21 inputs the signal from the receiving circuit 24 to the phase combining section 31 of the signal processing section 25. The reflected wave signal whose phase difference has been adjusted through the phase synthesis section 31 is subjected to B-mode processing at the B-mode data generation section 32. Thereafter, the image processing unit 34 performs image processing to generate image data of a tomographic image based on the signal output from the B-mode data generation unit 32. Then, the controller 21 causes the memory 26 to temporarily store the image data of the tomographic image.

In the subsequent step S130, the controller 21 inputs the reflected wave signal whose phase difference has been adjusted through the phase synthesis section 31 to the Doppler analysis section 41, and obtains information about the signal amount of the Doppler component by performing Doppler processing there. do. Further, the controller 21 inputs the Doppler signal from the Doppler analysis unit 41 to the filtering unit 42 to perform the above filtering process, and then inputs the signal to the image processing unit 34 to generate image data of a blood flow image. let The image processing unit 34 generates image display data in which a blood flow image is superimposed on a tomographic image generated based on the B-mode data. Then, the controller 21 temporarily stores this image display data in the memory 26.

In the subsequent step S140, the controller 21 reads the image display data from the memory 26, transfers it to the display device 28, and causes the display device 28 to display an image in which the blood flow image is superimposed on the tomographic image.

For example, when an operator issues an instruction to request calculation of blood flow area via the input device 29, a predetermined control signal is input to the controller 21. Then, the controller 21 determines whether or not to calculate the blood flow area based on the presence or absence of input of this control signal. If it is determined that the control signal is not input (step S150: NO), the controller 21 ends without executing any subsequent processing. If it is determined that the control signal is input (step S150: YES), the controller 21 moves to step S160, which is a blood flow area calculation process.

FIG. 6 shows subroutine processing related to calculation of blood flow area. The controller 21 first specifies the signal intensity near the boundary between the blood flow region R1 and the non-blood flow region R2 (step S161). Next, the controller 21 as display color replacement means replaces the display color 62 on the color index 61 corresponding to the designated signal strength with a specific display color that is not continuous in hue with the surrounding display colors 62 on the color index 61. The color is replaced with color 63 (here, blue) (step S162). As a result, as shown in FIG. 7, an image in which the image of the color index 61 after display color replacement is superimposed on the tomographic image is displayed on the display screen. Note that in the image of the color index 61 after display color replacement shown in FIG. It is located in In this case, a blood flow image in which the blood flow region R1 is surrounded by a single blue outline L1 is displayed on the display screen of the display device 28 (see FIG. 8).

As described above, the display color 62 of the color index 61 has a corresponding relationship with the signal intensity of the Doppler component. When the signal strength level of the Doppler signal is divided into 100 levels from "0 to 99", on the display screen in FIG. 63 has been replaced. Note that in FIG. 8, where the signal strength level is set extremely low, the area surrounded by the blue outline L1 in the displayed image is relatively large. Further, the width of the blue outline L1 itself is relatively wide.

Here, if the operator visually observes the display screen and determines that there is no need to adjust the signal strength value (step S163: NO), the operator inputs that effect via the input device 29. Then, the controller 21 moves to step S165, and determines the value of the signal intensity as the blood flow rate threshold δb for blood flow determination. Further, if it is determined that the signal strength value needs to be adjusted (step S163: YES), the operator operates the input device 29 to adjust the signal strength value stepwise or steplessly, and then adjusts the signal strength value stepwise or steplessly. Then, the controller 21 changes the signal strength value (step S164). For example, on the display screen of FIG. 9, the range corresponds to the levels "8 to 11" in the image of the color index 61, and on the display screen of FIG. 10, the range corresponds to the levels "14 to 17" in the image, On the display screen, the ranges corresponding to levels "57 to 60" in the image are each replaced with a specific display color 63. Comparing these display images with the display image in FIG. 8, it can be seen that the area surrounded by the blue outline L1 is not as large as in FIG. 8, and becomes smaller in FIGS. 9, 10, and 11. Furthermore, it can be seen that the width of the blue outline L1 itself is not as wide as in FIG. 8, and becomes narrower in FIGS. 9, 10, and 11. Then, the operator who has made such adjustments visually views these displayed images, specifies the range that he or she recognizes as the blood flow region R1 of the vascular network M1, and calculates the value of the signal intensity at that time as the blood flow region R1. The threshold value δb is determined for flow determination (step S165).

After the threshold value δb is determined as described above, the controller 21 inputs the filtered Doppler signal to the pixel number counting unit 44 and counts the number of pixels indicating blood flow in the region of interest 48 (step S167 ). Further, the controller 21 inputs the count result to the blood flow area calculation unit 45 to calculate the blood flow area, and temporarily stores the obtained blood flow area calculation data in the memory 26 (step S168). Then, the controller 21 reads out this blood flow area calculation data from the memory 26, transfers it to the display device 28, displays it on the display device 28 as a blood flow area value (step S170), and then ends the series of processing.

Therefore, according to this embodiment, the following effects can be obtained.

(1) In the ultrasound image diagnostic apparatus 11 of the present embodiment, the location corresponding to the signal intensity near the boundary between the blood flow region R1 and the non-blood flow region R2 has a hue that is different from the surrounding display color 62 on the color index 61. It is replaced with a specific display color 63 that is not consecutive. Therefore, in the blood flow image, the blood flow region R1 is displayed in a manner surrounded by a visually easy-to-understand color outline L1. Therefore, the boundary between the blood flow region R1 and the non-blood flow region R2 becomes easy to understand, and it is possible to easily determine at what level the signal intensity threshold δb appropriate for specifying the blood vessel network M1 should be set. becomes. Therefore, it is possible to relatively easily specify the range that the operator himself recognizes as the blood flow region R1 of the blood vessel network M1, making it easier to quantitatively evaluate the blood flow distribution. Furthermore, according to the present embodiment, there is no need for the operator to manually trace the range that he or she recognizes as a blood flow region, so there is no need to perform the troublesome work of manually tracing the range that the operator recognizes as the blood flow region. is resolved.

(2) In the ultrasound image diagnostic apparatus 11 of this embodiment, since the controller 21 functions as a signal intensity adjustment means, the specified signal intensity value can be adjusted as appropriate. Therefore, the level of the threshold value δb can be set more appropriately, and the blood flow region of the vascular network M1 can be specified more easily and accurately.

(3) In the ultrasound diagnostic imaging apparatus 11 of this embodiment, in addition to the blood flow image, the image of the color index 61 is displayed superimposed on the tomographic image. As a result, it becomes easier to intuitively understand where the replaced specific display color 63 is located in the color index image 61 (that is, what level the specified threshold δb is).

(4) In the ultrasound image diagnostic apparatus 11 of this embodiment, when filtering blood flow information by the filtering section 42 of the blood flow mapping data generation section 33, the weighting coefficient of input data is switched. In other words, when the blood flow changes in the direction of increase, by switching the weighting coefficient to a larger value (i.e., from α2 to α1), the contribution rate of the input data increases, making it possible to quickly detect the blood flow. . Furthermore, when the blood flow changes in a decreasing direction, by switching the weighting coefficient to a smaller value (that is, from α1 to α2), the contribution rate of the input data becomes smaller, and the blood flow detection state can be maintained for a while. becomes possible. In other words, according to the present embodiment, as a result of smoothing the blood flow information as described above, it becomes easier to visually perceive microvessels, and it becomes easier to detect blood flow in microvessels with little blood flow. Based on such blood flow detection, a threshold value is determined as to whether or not there is blood flow within the region of interest 48, the number of pixels indicating blood flow is counted, and the blood flow area is calculated from the counted number. , the blood flow distribution of the vascular network M1 can be easily and quantitatively evaluated. When the device 11 of this embodiment is used for pregnancy testing of livestock, it becomes possible to easily and accurately determine whether the livestock is pregnant at a relatively early stage.

Note that the embodiment of the present invention may be modified as follows.

- In the above embodiment, the specific display color 63 in the color index 61 is blue, but it is not limited to this; for example, it may also be a cool color other than blue, such as green, light blue, or indigo. Of course it's good. In this case, the replaced specific display color 63 becomes significantly different in hue from the surrounding display colors 62. Therefore, as in the above embodiment, there is an advantage that the outline L1 made of the specific display color 63 can be easily grasped visually.

- In the above embodiment, the display color 62 that continuously changes in the color index 61 is a warm color, and the specific display color 63 is a cool color, but the present invention is not limited to this. That is, the display color 62 that continuously changes in the color index 61 may be a cool color, and the specific display color 63 may be a warm color such as red, orange, yellow, etc.

- In the above embodiment, even when the level of the signal intensity of the Doppler signal is adjusted, the width of the specific display color 63 in the image of the color index 61 is constant, but the width is configured to be changeable. Good too. Specifically, the configuration may be such that the level can be changed, for example, "8 to 11", "7 to 12", and "6 to 13".

- In the above embodiment, as shown in the graph of FIG. 4, the filtering process is performed by setting two stages of weighting coefficients α1 and α2, but for example, the filtering process is performed by setting the weighting coefficients of three or more stages. It's okay. Alternatively, a weighting constant may be set that increases in a stepless manner as the blood flow increases, and the filtering process may be performed based on this.

- In the above embodiment, the subject 19 is a livestock such as a cow, a horse, or a pig, but the subject 19 may be an animal other than livestock or a human. Furthermore, it goes without saying that the ultrasound imaging apparatus 11 of the above embodiment may be used for purposes other than pregnancy testing, such as observing the state of an injured site or malignant neoplasm, and observing the progress of healing.

- In this embodiment, the calculation result of the blood flow area is directly displayed as a numerical value on the display screen of the display device 28, but it does not necessarily have to be a numerical value. It may be displayed indirectly using an icon or the like. Alternatively, instead of displaying the blood flow area directly or indirectly, it may be displayed using characters such as "pregnant" or "not pregnant."

11...Ultrasonic image diagnostic apparatus 19 as an ultrasonic blood flow region display device...Subject 21...Controller 27 as signal intensity designation means, display color replacement means, and signal intensity adjustment means...Storage device 32 as storage means...B Mode data generation unit 33...Blood flow mapping data generation unit 34...Image processing unit 61...Color index 62...Display color 63...Specific display color R1...Blood flow region R2...Non blood flow region M1...Vessel network

Claims (7)

a B-mode data generation unit that generates tomographic image data by performing B-mode processing on signals obtained by transmitting and receiving ultrasound to and from the subject;
a blood flow mapping data generation unit that generates blood flow mapping data based on blood flow information obtained by Doppler analysis of the signal;
The blood flow image data is generated by converting the blood flow mapping data into color information with reference to a color index in which a display color whose hue continuously changes corresponds to the signal intensity of the signal, and An apparatus comprising: an image processing unit that generates image display data in which the blood flow image is superimposed on a tomographic image,
signal strength designating means for designating the signal strength near the boundary between a blood flow region and a non-blood flow region;
Display color replacement means for replacing the display color on the color index corresponding to the specified signal strength with a specific display color that is not continuous in hue with surrounding display colors on the color index. . An ultrasonic blood flow region display device, wherein the image processing unit generates data of the blood flow image in which the blood flow region is surrounded by the replaced specific display color. The ultrasonic blood flow region display device according to claim 1, further comprising signal intensity adjustment means for adjusting the value of the signal intensity specified by the signal intensity specification means. The image display data is obtained by superimposing the blood flow image and the color index in which the display color corresponding to the designated signal intensity is replaced with the specific display color on the tomographic image. The ultrasonic blood flow region display device according to claim 1 or 2, characterized in that: 4. The display color according to claim 1, wherein the display color that continuously changes in the color index is a warm color, and the specific display color is a cool color. Ultrasonic blood flow area display device. a B-mode data generation step of generating tomographic image data by performing B-mode processing on signals obtained by transmitting and receiving ultrasound to and from the subject;
a blood flow mapping data generation step of generating blood flow mapping data based on blood flow information obtained by Doppler analysis of the signal;
a signal strength specification step of specifying signal strength near the boundary between the blood flow region and the non-blood flow region;
On a color index in which a display color whose hue changes continuously and the signal strength of the signal correspond to each other, the display color corresponding to the specified signal strength is set to the surrounding display color on the color index. a display color replacement step of replacing the display color with a specific display color that is not continuous in hue;
By converting the blood flow mapping data into color information with reference to the color index, data of a blood flow image in which the blood flow region is surrounded by the replaced specific display color is generated, and An ultrasonic blood flow region display method comprising: an image processing step of generating image display data in which the blood flow image is superimposed on the tomographic image. to the processor,
a B-mode data generation step of generating tomographic image data by performing B-mode processing on signals obtained by transmitting and receiving ultrasound to and from the subject;
a blood flow mapping data generation step of generating blood flow mapping data based on blood flow information obtained by Doppler analysis of the signal;
a signal strength specification step of specifying signal strength near the boundary between the blood flow region and the non-blood flow region;
On a color index in which a display color whose hue changes continuously and the signal strength of the signal correspond to each other, the display color corresponding to the specified signal strength is set to the surrounding display color on the color index. a display color replacement step of replacing the display color with a specific display color that is not continuous in hue;
By converting the blood flow mapping data into color information with reference to the color index, data of a blood flow image in which the blood flow region is surrounded by the replaced specific display color is generated, and an ultrasonic blood flow region display program for executing an image processing step of generating image display data in which the blood flow image is superimposed on the tomographic image. An ultrasonic image diagnostic apparatus comprising a storage means storing the program according to claim 6.

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