Ultrasonic diagnosis device

Abstract

To display a low-speed blood flow and enable display of a valid blood flow speed with suppressed clutters in a blood flow image displayed on an ultrasonic diagnosis device.SOLUTION: An ultrasonic diagnosis device according to an embodiment includes: an acquiring unit for acquiring reflected ultrasonic wave data from a moving body; a first filter processing unit for extracting speed information for the moving body by applying a first filter to the reflected ultrasonic wave data; a determination unit for determining a likelihood of the moving body being a blood flow based on the reflected ultrasonic wave data and outputting the likelihood information; and a blood flow image generation unit for generating a blood flow image based on the speed information for the moving body extracted by the first filter processing unit and the likelihood information output by the determination unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to an ultrasonic diagnostic apparatus.

Background Art

[0002] In an ultrasonic diagnostic apparatus, information regarding the intensity and velocity of blood flow is displayed on a display as a blood flow image represented by color changes on reflected wave ultrasonic data. When generating this blood flow image, there is a technique that uses color flow mapping (CFM) in which colors are assigned to the velocity of blood flow. In such a technique, unnecessary signals (clutter) included in the reflected wave ultrasonic data obtained from the received reflected waves are removed by a wall filter, thereby extracting information such as the intensity of blood flow, the velocity of blood flow, and the direction of blood flow.

[0003] However, even when trying to remove clutter by such a method, there are cases where it cannot be completely removed. Therefore, in order to suppress the remaining clutter from deteriorating the visibility of the blood flow image, there are sometimes devices such as assigning colors on the color map so that parts with slow blood flow velocity are displayed in dark colors. However, when using such a color map, slow blood flow is less likely to be displayed in the blood flow image.

[0004] When trying to display slow blood flow, since clutter distributed in the low-speed component overlaps with the blood flow in the velocity region, it is necessary to separate them. For this reason, in recent years, eigenvalue expansion type wall filters are used to separate slow blood flow and clutter. However, since the filter characteristics of the eigenvalue expansion type wall filter are variable according to the input, there is a problem that the validity of the value regarding the velocity of blood flow estimated after filtering is not ensured.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to display slow blood flow while suppressing clutter in the blood flow image displayed by the ultrasonic diagnostic apparatus, and to realize a valid display of the blood flow velocity. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. The problems corresponding to the respective effects of the respective configurations shown in the embodiments described later can also be regarded as other problems. [Means for Solving the Problems]

[0007] The ultrasonic diagnostic apparatus according to the embodiment includes an acquisition unit that acquires reflected wave ultrasonic data from a moving object, a first filter processing unit that extracts velocity information of the moving object by applying a first filter to the reflected wave ultrasonic data, a determination unit that determines the probability that the moving object is blood flow based on the reflected wave ultrasonic data and outputs probability information, and a blood flow image generation unit that generates a blood flow image based on the velocity information of the moving object extracted by the first filter processing unit and the probability information output by the determination unit. [Brief Description of the Drawings]

[0008]

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Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of an ultrasonic diagnostic apparatus will be described with reference to the drawings. In the following description, components having substantially the same functions and configurations will be denoted by the same reference numerals, and redundant descriptions will be made only when necessary.

[0010] FIG. 1 is a block diagram showing an example of an ultrasonic diagnostic apparatus 100 according to the present embodiment. As shown in FIG. 1, the ultrasonic diagnostic apparatus 100 includes an apparatus main body 10, an ultrasonic probe 1 connected to the main body apparatus 10, a display 2, and an input device 3.

[0011] The apparatus main body 10 includes a transmission / reception circuit 101, a buffer memory 102, a B-mode processing circuit 103, a Doppler processing circuit 104, an output interface 105, an input interface 106, an image generation circuit 107, a display control circuit 108, an image memory 109, a storage circuit 110, a control circuit 111, and a NW (network) interface 112. The apparatus main body 10 is connected to an external device 200 via a network NW.

[0012] The ultrasonic probe 1 has a plurality of elements such as piezoelectric vibrators, for example. These plurality of elements generate ultrasonic waves based on a drive signal supplied from the transmission / reception circuit 101 of the apparatus main body 10. The ultrasonic probe 1 also receives a reflected wave from the subject P and converts it into an electrical signal. Further, the ultrasonic probe 1 has, for example, a matching layer provided on the piezoelectric vibrator and a backing material that prevents the propagation of ultrasonic waves rearward from the piezoelectric vibrator. The ultrasonic probe 1 is detachably connected to the apparatus main body 10.

[0013] More specifically, when ultrasonic waves are transmitted from the ultrasonic probe 1 to the subject P, the transmitted ultrasonic waves are successively reflected at the discontinuous surfaces of the acoustic impedance in the body tissues of the subject P and received by the plurality of elements included in the ultrasonic probe 1 as reflected wave signals. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic waves are reflected. When the transmitted ultrasonic pulse is reflected at the surface of a moving blood flow or the heart wall, etc., the reflected wave signal undergoes a frequency shift depending on the velocity component of the moving object with respect to the ultrasonic transmission direction due to the Doppler effect. Then, the ultrasonic probe 1 outputs the reflected wave signal to the transmission / reception circuit 101 of the apparatus main body 10.

[0014] In this embodiment, the ultrasonic probe 1 is, for example, a one-dimensional array probe in which a plurality of ultrasonic transducers are arranged along a predetermined direction. However, the ultrasonic probe 1 is not limited to a one-dimensional array probe, and may be a two-dimensional array probe (a probe in which a plurality of ultrasonic transducers are arranged in a two-dimensional matrix), or a mechanical 4D probe (a probe capable of performing ultrasonic scanning while mechanically oscillating an ultrasonic transducer array in a direction orthogonal to the array direction).

[0015] The input device 3 is realized by input means such as a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, etc., for example. The input device 3 receives various setting requests from the operator of the ultrasonic diagnostic apparatus 100 and transfers the received various setting requests to the apparatus main body 10.

[0016] The display 2 displays, for example, a GUI (Graphical User Interface) for the operator of the ultrasonic diagnostic apparatus 100 to input various setting requests using the input device 3, or displays an ultrasonic image or the like indicated by the ultrasonic image data generated in the apparatus main body 10. The display 2 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, or the like. The display 2 is an example of a display unit.

[0017] The transmission / reception circuit 101 causes the ultrasonic probe 1 to transmit ultrasonic waves under the control of the control circuit 111, and causes the ultrasonic probe 1 to receive ultrasonic waves (reflected waves of ultrasonic waves). That is, the transmission / reception circuit 101 executes ultrasonic scanning (ultrasonic scan) via the ultrasonic probe 1.

[0018] More specifically, the transmission / reception circuit 101 receives control by the control circuit 111 and causes the ultrasonic probe 1 to transmit ultrasonic waves. The transmission / reception circuit 101 has, for example, a trigger generation circuit, a delay circuit, a pulsar circuit, etc., not shown in the figure. In the trigger generation circuit, trigger pulses for forming transmitted ultrasonic waves at a predetermined repetition frequency fr Hz are repeatedly generated. Also, in the delay circuit, a delay time necessary for focusing ultrasonic waves in a beam shape for each channel and determining transmission directivity is given to each trigger pulse. The pulsar circuit applies a drive pulse to the ultrasonic probe 1 at the timing based on this trigger pulse.

[0019] Also, the transmission / reception circuit 101 generates reflected-wave ultrasonic data, which is ultrasonic data, based on the reflected-wave signal received by the ultrasonic probe 1. Then, the transmission / reception circuit 101 stores the generated reflected-wave ultrasonic data in the buffer memory 102.

[0020] More specifically, after the reflected wave of the ultrasonic wave transmitted by the ultrasonic probe 1 reaches the piezoelectric vibrator inside the ultrasonic probe 1, at the piezoelectric vibrator, it is converted from mechanical vibration into an electrical signal (reflected-wave signal) and input to the transmission / reception circuit 101. The transmission / reception circuit 101 has, for example, a preamplifier, an A / D (Analog to Digital) converter, an orthogonal detection circuit, etc., and performs various processes on the reflected-wave signal received by the ultrasonic probe 1 to generate reflected-wave ultrasonic data. In the present embodiment, when "acquiring reflected ultrasonic data" is mentioned, it includes obtaining reflected-wave ultrasonic data from the moving body by transmitting and receiving ultrasonic waves. The transmission / reception circuit 101 is an example of the acquisition unit in the present embodiment.

[0021] The buffer memory 102 stores at least temporarily the reflected-wave ultrasonic data generated by the transmission / reception circuit 101. For example, the buffer memory 102 stores the reflected-wave ultrasonic data obtained by performing transmission and reception of ultrasonic waves a plurality of times for each raster. The buffer memory 102 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory.

[0022] The B-mode processing circuit 103 performs processes such as logarithmic amplification, envelope detection, and logarithmic compression on the reflected wave ultrasonic data read from the buffer memory 102, and generates data (B-mode data) in which the signal intensity is expressed by the brightness of the luminance.

[0023] The Doppler processing circuit 104 generates data (Doppler data) in which motion information based on the Doppler effect of a moving object within an ROI (Region Of Interest) set in the scan region is extracted by performing frequency analysis on the reflected wave ultrasonic data stored in the buffer memory 102. The moving object is, for example, blood. For example, the Doppler processing circuit 104 can execute a color Doppler method also called a color flow mapping (CFM) method.

[0024] The output interface 105 outputs an electrical signal from the control circuit 111 to the outside. The output interface 105 is connected to the control circuit 111 via, for example, a bus, and outputs the electrical signal from the control circuit 111 to the display 2.

[0025] The input interface 106 receives various instructions from the operator via the input device 3. The input interface 106 is connected to the control circuit 111 via, for example, a bus, converts the operation instructions input from the operator into electrical signals, and outputs the electrical signals to the control circuit 111. Note that the input interface 106 is not limited to being connected to physical operation components such as a mouse and a keyboard. For example, a circuit that receives an electrical signal corresponding to an operation instruction input from an external input device provided separately from the ultrasonic diagnostic apparatus 100 and outputs this electrical signal to the control circuit 111 is also included in the examples of the input interface.

[0026] The image generation circuit 107 generates ultrasonic image data based on the data generated by the B-mode processing circuit 103 and the Doppler processing circuit 104. The image generation circuit 107 stores the generated ultrasonic image data in the image memory 109.

[0027] More specifically, the image generation circuit 107 generates B-mode image data based on the B-mode data generated by the B-mode processing circuit 103. Further, the image generation circuit 107 generates Doppler image data based on the Doppler data generated by the Doppler processing circuit 104. The Doppler image data is an example of data for displaying a blood flow image in the present embodiment. The image generation circuit 107 generates Doppler image data based on the intensity information and the phase change information included in the Doppler data generated by the Doppler processing circuit 104.

[0028] The Doppler image data is, for example, velocity image data, dispersion image data, power image data, or image data combining these. For example, the image generation circuit 107 generates, as Doppler image data, data of a blood flow image in which blood flow information is displayed in color from the Doppler data as blood flow information. In this case, the image generation circuit 107 visualizes the blood flow as Doppler image data by determining the drawing position according to the signal intensity of the blood flow and the display color according to the velocity and direction of the blood flow. The image generation circuit 107 is an example of a blood flow image generation unit in the present embodiment.

[0029] The display control circuit 108 causes the display 2 to display an ultrasonic image based on various ultrasonic image data generated by the image generation circuit 107. Further, the display control circuit 108 may cause the display 2 to display a GUI for the operator to input various setting requests using the input device 3.

[0030] The image memory 109 stores various image data generated by the control circuit 111. For example, the image memory 109 is realized by a semiconductor memory element such as a RAM or a flash memory, a hard disk, or an optical disk.

[0031] The memory circuit 110 is realized by, for example, a magnetic or optical storage medium, a semiconductor memory element such as a flash memory, a hard disk, or a storage medium readable by a processor such as an optical disk. The memory circuit 110 stores a program for realizing ultrasonic transmission and reception, various data, etc. The program and various data may be stored in the memory circuit 110 in advance, for example. Also, for example, they may be stored in a non-transitory storage medium, distributed, read from the non-transitory storage medium, and installed in the memory circuit 110. Note that the memory circuit 110 may be regarded as an example of the storage unit in the present embodiment.

[0032] The control circuit 111 comprehensively controls the operation of the entire ultrasonic diagnostic apparatus 100. For example, the control circuit 111 controls the ultrasonic probe 1 via the transmission / reception circuit 101 to control ultrasonic scanning and acquire reflected wave ultrasonic data.

[0033] The NW interface 112 is connected to an external device 200 via, for example, a network NW and performs data communication with the external device 200.

[0034] The external device 200 is, for example, a workstation that executes post-processing of various data generated by the ultrasonic diagnostic apparatus 100 and processing such as display of ultrasonic image data. The external device 200 includes, for example, a processing circuit such as a processor, a storage device, a display, an input device, and an NW interface connectable to the ultrasonic diagnostic apparatus 100 via a network NW. Also, the external device 200 may be a tablet terminal or the like.

[0035] Next, the Doppler processing circuit 104 will be described in detail. FIG. 2 is a block diagram showing an example of the functions of the Doppler processing circuit 104 according to the present embodiment. As shown in this FIG. 2, the Doppler processing circuit 104 includes a power WF (Wall Filter) function 131, a power estimation function 132, a blood flow possibility determination function 133, a velocity / direction WF function 141, an autocorrelation processing function 142, a velocity / direction estimation function 143, and a packing function 151.

[0036] The power WF function 131 and the speed / direction WF function 141 apply wall filters to the ensemble data 300, which is the reflected wave ultrasonic data stored in the buffer memory 102, respectively.

[0037] More specifically, the power WF function 131 extracts intensity information regarding the moving object by applying a wall filter for power (intensity) information to the ensemble data 300. The power WF function 131 uses an eigenvalue decomposition type wall filter. The power WF function 131 is an example of the second filter processing unit in the present embodiment. Further, the eigenvalue decomposition type wall filter applied to the ensemble data 300 by the power WF function 131 is an example of the second filter in the present embodiment.

[0038] The eigenvalue decomposition type wall filter is, for example, an adaptive MTI (Moving Target Indicator) filter that changes coefficients according to an input signal using an eigenvector. The eigenvector is calculated from a correlation matrix. Specifically, the power WF function 131 calculates a correlation matrix of the scanning range from a data series of reflected wave ultrasonic data at the same position collected over a plurality of frames. The power WF function 131 calculates an eigenvector from the correlation matrix and determines coefficients to be used for the MTI filter based on the calculated eigenvector. Note that the adaptive MTI filter using an eigenvector is an example of the eigenvalue decomposition type wall filter, and other methods may be adopted.

[0039] In the eigenvalue expansion type wall filter, those with large energy in the eigenvector dimension of the ensemble data 300 are detected as the main components, and the Doppler shift (Doppler offset) that spatially approximates the main components is suppressed as the clutter component. Such an eigenvalue expansion type wall filter is excellent in clutter suppression ability and extraction of the power component of blood flow. On the other hand, since the characteristics of the filter change according to the correlation matrix of the scanning range, when speed information and direction information are estimated for the signal after passing through the filter, it becomes impossible to say what information in which speed range is extracted.

[0040] The power estimation function 132 estimates the intensity information of the moving object from the components extracted from the ensemble data 300 by the WF function 131 for power. The power estimation function 132 is an example of the power estimation unit in the present embodiment.

[0041] The blood flow possibility determination function 133 determines the probability that the moving object is blood flow based on the intensity information of the moving object estimated by the power estimation function 132. This determination result is output from the blood flow possibility determination function 133 as accuracy information. For example, in the present embodiment, the accuracy information is generated so that it increases as the intensity of the intensity information of the moving object increases. That is, in the present embodiment, it is determined that the higher the intensity of the moving object, the higher the probability that the moving object is blood flow. This is because generally, when the moving object is a tissue such as an organ or just noise, the intensity of the reflected wave ultrasonic data is considered to be weak. This blood flow possibility determination function 133 is an example of the determination unit in the present embodiment.

[0042] The velocity / direction WF function 141 extracts phase change information by applying a wall filter for velocity / direction to the ensemble data 300. The velocity / direction WF function 141 uses a fixed-length wall filter in the Doppler frequency space. The phase change information includes the velocity information and direction information of the moving object. In this embodiment, the velocity / direction WF function 141 is an example of a first filter processing unit that extracts the velocity information of the moving object. Also, the fixed-length wall filter used by the velocity / direction WF function 141 is an example of the first filter in this embodiment.

[0043] More specifically, in this embodiment, the velocity / direction WF function 141 uses a polynomial approximation type wall filter. In the polynomial approximation type wall filter, fitting is performed with a predetermined polynomial, and clutter components are removed by a polynomial fitting method that identifies components of a lower order as clutter components. Note that a fixed-length wall filter other than the polynomial approximation type wall filter may be employed. For example, the velocity / direction WF function 141 may use an IIR (Infinite Impulse Response) filter.

[0044] In the fixed-length wall filter, components with a low Doppler shift frequency are regarded as clutter and suppressed. The Doppler shift frequency is low in reflected wave ultrasonic data derived from stationary tissues or tissues with slow movement. The fixed-length wall filter may have lower clutter and blood flow separation ability compared to the eigenvalue expansion type wall filter. However, in the fixed-length wall filter, since the characteristics of the filter are uniquely determined, it is possible to estimate with validity as the changes in the velocity and direction information of the blood flow within the filter pass velocity range.

[0045] The autocorrelation processing function 142 performs autocorrelation processing on the data extracted from the ensemble data 300 by the velocity / direction WF function 141. The autocorrelation processing function 142 is an example of an autocorrelation processing unit.

[0046] The speed and direction estimation function 143 estimates the speed information and direction information of the moving object based on the result of the autocorrelation process by the autocorrelation processing function 142. The speed and direction estimation function 143 is an example of a speed and direction estimation unit. Note that the speed and direction estimation function 143 may also estimate the variance of the moving object. When the speed and direction estimation function 143 estimates the variance of the moving object, the speed and direction estimation function 143 also generates variance information.

[0047] The packing function 151 combines the accuracy information output from the blood flow possibility determination function 133 with the speed information and direction information of the moving object estimated by the speed and direction estimation function 143 to generate Doppler data 310 including the accuracy information, speed information, and direction information of the moving object. A blood flow image is generated by the image generation circuit 107 from the Doppler data 310 generated by the packing function 151. Note that when the speed and direction estimation function 143 also generates variance information, the packing function 151 combines the variance information in addition to the accuracy information, speed information, and direction information of the moving object to generate the Doppler data 310. The packing function 151 is an example of a packing unit in the present embodiment.

[0048] Next, the process of the image generation circuit 107 generating a blood flow image will be described in detail. FIG. 3 is a block diagram for explaining the processing content of the image generation circuit 107 in the apparatus main body 10 of the ultrasonic diagnostic apparatus 100 according to the present embodiment. As shown in this FIG. 3, the image generation circuit 107 according to the present embodiment acquires the Doppler data 310 output by the packing function 151 of the Doppler processing circuit 104. In the present embodiment, since this Doppler data 310 is also generated from the reflected wave ultrasonic data, the reflected wave ultrasonic data may be synonymous with the Doppler data 310.

[0049] More specifically, the image generation circuit 107 acquires Doppler data 310 and obtains the probability information, velocity information, and direction information included in the Doppler data 310. Then, based on the acquired probability information, velocity information, and direction information, a blood flow image 320 is generated. However, in the present embodiment, the image generation circuit 107 generates the blood flow image 320 such that the higher the probability of blood flow in the probability information, the higher the brightness, and conversely, the lower the probability, the lower the brightness. The blood flow image 320 generated by the image generation circuit 107 is temporarily stored in, for example, the image memory 109 and displayed on the display 2.

[0050] FIG. 4 is a diagram showing an example of a color map 400 used when the image generation circuit 107 generates the blood flow image 320 based on the probability information, velocity information, and direction information. In the present embodiment, the color map 400 may be held by, for example, the image generation circuit 107 itself. Alternatively, the color map 400 may be stored in the storage circuit 110, and the image generation circuit 107 may read out and use the color map 400 from the storage circuit 110.

[0051] The color map 400 has, for example, the horizontal axis indicating the probability that the moving object is blood flow and the vertical axis indicating the velocity of the moving object. The probability of blood flow in the color map 400 is determined based on the probability information included in the Doppler data 310. The velocity of the moving object in the color map 400 is determined based on the velocity information and direction information included in the Doppler data 310. In the present embodiment, the horizontal axis corresponds to the first axis and the vertical axis corresponds to the second axis, but the relationship between the vertical axis and the horizontal axis can be interchanged.

[0052] Also, in the example of FIG. 4, the color is arranged such that the saturation of red increases as the speed of the moving object moving in the direction approaching the ultrasonic probe 1 increases, and the saturation of blue increases as the speed of the moving object moving in the direction away from the ultrasonic probe 1 increases. In other words, in this color map 400, the difference in the fast / slow speed of the moving object is not represented by the difference in brightness. Further, in the example of FIG. 4, the color is arranged such that the higher the probability of being blood flow, the higher the brightness. Therefore, in the blood flow image, the lower the probability of being blood flow in a region, the closer the color displayed is to black.

[0053] Also, in the example of FIG. 4, white is assigned to a moving object with a speed of zero. Therefore, even when the speed of the moving object is zero, that is, even when the moving object is stationary, if the probability of being blood flow is high, white is displayed in that region. Therefore, in the blood flow image, when the probability of being blood flow is high, even in a region where the speed of the moving object is slow, white or a color close to white is displayed. Here, white is an example of a bright color. For example, in the color map 400, it is also possible to arrange yellow instead of white.

[0054] In the color map 400 shown in FIG. 4, red, which is the first color, is assigned to a moving object moving in the direction approaching the ultrasonic probe 1, blue, which is the second color, is assigned to a moving object moving in the direction away from the ultrasonic probe 1, and white, which is the third color, is assigned to a moving object with a moving speed of zero. And these first color red, second color blue, and third color white are arranged to gradually change based on the probability of being blood flow and the speed of the moving object.

[0055] Based on such a color map 400, when the image generation circuit 107 generates a blood flow image, clutter is suppressed, slow blood flow is also displayed, and the blood flow velocity is displayed validly. That is, by applying a fixed-length wall filter to the ensemble data 300 which is reflected wave ultrasonic data in the velocity / direction WF function 141, the clutter component is removed and suppressed. Then, since the image generation circuit 107 generates a blood flow image based on the color map 400, even for a slow region, for example, a minute blood flow, if the probability of being blood flow is high, white is colored in the blood flow image. Therefore, even minute blood flow or slow blood flow can be displayed in the blood flow image. Also, in a region where the velocity of the moving body is high, red or blue can be colored, and the blood flow velocity can be displayed validly.

[0056] FIG. 5 is a diagram showing another example of the color map 400. Also in the example shown in this FIG. 5, it is colored such that the higher the probability of being blood flow, the higher the brightness. Therefore, in the blood flow image, the lower the probability of being blood flow in a region, the blacker or the closer to black the color displayed. On the other hand, in the example of FIG. 5, when the velocity of the moving body is zero, that is, when the moving body is stationary, if the probability of being blood flow is high, purple is colored. Therefore, in the blood flow image, if the probability of being blood flow is high, even in a region where the velocity of the moving body is slow, purple or a color close to purple is displayed.

[0057] Also, in the example of FIG. 5, it is colored such that as the velocity increases in the direction approaching the ultrasonic probe 1, it gradually changes from purple to blue and then gradually to white. Further, as the velocity increases in the direction away from the ultrasonic probe 1, it gradually changes from purple to red and then gradually to white.

[0058] That is, in the color map 400 shown in FIG. 5, purple, which is the first color, is assigned to the moving object with a moving speed of zero, and white, which is the second color, is assigned to the maximum values on the color map 400 regarding the speeds of the moving object moving in the direction approaching the ultrasonic probe 1 and the moving object moving in the receding direction, respectively. Then, as the speed of the moving object increases in the direction approaching the ultrasonic probe 1, the color is arranged to change from blue, which is the third color, to white, which is the second color, and as the speed of the moving object increases in the direction receding from the ultrasonic probe 1, the color is arranged to change from red, which is the fourth color, to white, which is the second color.

[0059] Even when using the color map 400 with the color arrangement as shown in this FIG. 5, the image generation circuit 107 can display the blood flow with a slow speed while suppressing clutter and display the speed of the blood flow validly. This is because in the color map 400 according to the present embodiment, the color is arranged such that the higher the probability of being blood flow, the higher the brightness. Thereby, the display intensity of the blood flow image generated by the image generation circuit 107 can be adjusted so that the blood flow with a slow speed can be displayed while the blood flow is displayed in the color of an appropriate speed value. Therefore, for the color arrangement of the color map 400, any combination of colors can be used as long as the condition that the higher the probability of being blood flow, the higher the brightness is satisfied.

[0060] Note that the B-mode processing circuit 103, the Doppler processing circuit 104, the image generation circuit 107, the display control circuit 108, and the control circuit 111 are realized by a processor. For example, a computer-executable program in which the processing executed by these circuits is defined is stored in the storage circuit 110. These circuits read out the program from the storage circuit 110 and execute it to realize the functions corresponding to the respective programs. Also, in FIG. 1, a single storage circuit 110 has been described as storing the programs corresponding to the respective processing functions, but a configuration may be adopted in which a plurality of storage circuits are arranged dispersedly and each circuit reads out the corresponding program from an individual storage circuit.

[0061] FIG. 6 is a diagram showing an example of a blood flow image 320 displayed on the display 2 of the ultrasonic diagnostic apparatus 100 according to the present embodiment, and FIG. 7 is a diagram showing, as a comparative example, a blood flow image generated by applying a wall filter for velocity and direction to ensemble data 300 which is reflected wave ultrasonic data, obtaining velocity information, and performing color mapping based on this velocity information. The blood flow images shown in FIGS. 6 and 7 are still images, but the blood flow image displayed on the display 2 may be a moving image.

[0062] As can be seen by comparing FIGS. 6 and 7, in the blood flow image 320 displayed on the ultrasonic diagnostic apparatus 100 according to the present embodiment shown in FIG. 6, the signal portion of the blood flow is emphasized and displayed, and the blood vessel can be recognized as a tube. In addition, since adjacent blood vessels can be separated, the state of the blood flow can be grasped more accurately.

[0063] Next, based on FIG. 8, the blood flow image display process executed by this ultrasonic diagnostic apparatus 100 will be described. FIG. 8 is a diagram showing a flowchart for explaining the blood flow image display process executed by the Doppler processing circuit 104, the image generation circuit 107, and the control circuit 111 in the ultrasonic diagnostic apparatus 100. The blood flow image display process shown in FIG. 8 is a process realized by, for example, the Doppler processing circuit 104, the image generation circuit 107, and the control circuit 111 reading out a blood flow image display process program stored in the storage circuit 110 and cooperating to execute it.

[0064] In this blood flow image display process, first, the control circuit 111 in the ultrasonic diagnostic apparatus 100 controls the transmission / reception circuit 101 to transmit ultrasonic waves from the ultrasonic probe 1 to the subject P, receive the reflected waves from the moving body of the subject P, and store them in the buffer memory 102 as reflected wave ultrasonic data (step S11). This reflected wave ultrasonic data is also the above-described ensemble data 300.

[0065] Next, the power WF function 131 and the velocity / direction WF function 141 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 acquire reflected wave ultrasonic data stored in the buffer memory 102 (step S13). In other words, the Doppler processing circuit 104 acquires the reflected wave ultrasonic data from the buffer memory 102.

[0066] Next, the velocity / direction WF function 141 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 extracts phase change information by applying a wall filter for velocity / direction to the ensemble data 300 which is the reflected wave ultrasonic data (step S15). As described above, here, the velocity / direction WF function 141 uses a fixed-length wall filter in the Doppler frequency space.

[0067] Next, the autocorrelation processing function 142 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 performs autocorrelation processing on the data extracted from the ensemble data 300 by the velocity / direction WF function 141 (step S17).

[0068] Next, the velocity / direction estimation function 143 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 estimates the velocity information and direction information of the blood flow based on the result of the autocorrelation processing by the autocorrelation processing function 142 (step S19).

[0069] On the other hand, after acquiring the ensemble data 300 which is the reflected wave ultrasonic data in step S13, the ultrasonic diagnostic apparatus 100 executes a blood flow possibility determination process (step S21). By this blood flow possibility determination process, based on the reflected wave ultrasonic data, the probability that the moving object included in this reflected wave ultrasonic data is blood flow is calculated.

[0070] FIG. 9 is a diagram showing a flowchart for explaining in detail the content of the blood flow possibility determination process in this step S21. This blood flow possibility determination process is a process realized, for example, by the Doppler processing circuit 104 reading and executing a blood flow possibility determination process program stored in the storage circuit 110.

[0071] As shown in FIG. 9, in the blood flow possibility determination process, first, the power WF function 131 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 applies a wall filter for power (intensity) information to the ensemble data 300 which is reflected wave ultrasonic data, thereby extracting intensity information regarding the moving object (step S31). As described above, here, the power WF function 131 uses an eigenvalue expansion type wall filter.

[0072] Next, the power estimation function 132 of the Doppler processing circuit 104 in the ultrasonic diagnostic apparatus 100 estimates the intensity information of the moving object from the components extracted from the ensemble data 300 by the power WF function 131 (step S33).

[0073] The blood flow possibility determination function 133 determines the probability that the moving object is blood flow based on the intensity information of the moving object estimated by the power estimation function 132 (step S35). In the present embodiment, for example, the probability that the moving object is blood flow is calculated as probability information. This probability information is calculated as a numerical value between 0% and 100%, for example. By executing this step S35, the blood flow possibility determination process ends.

[0074] Returning to FIG. 8 again, in the blood flow image display process of FIG. 8, the image generation circuit 107 in the ultrasonic diagnostic apparatus 100 generates a blood flow image 320 based on the blood flow velocity information and direction information generated in step S19 and the probability information generated in step S35 (step S23). As described above, the image generation circuit 107 uses the color map 400 to generate a blood flow image 320 with colors assigned to corresponding regions based on the probability information indicating the probability of being blood flow, the velocity information, and the direction information.

[0075] Next, the image generation circuit 107 in the ultrasonic diagnostic apparatus 100 displays the generated blood flow image 320 on, for example, the display 2 (step S25). For example, in the present embodiment, the generated blood flow image 320 is stored in the image memory 109, and the blood flow image 320 is displayed on the display 2. Thereby, the blood flow image display process according to the present embodiment ends.

[0076] As described above, according to the ultrasonic diagnostic apparatus 100 according to the present embodiment, it is possible to appropriately display a blood flow with a slow speed in the blood flow image 320 while suppressing the display of clutter. Also, the color scheme in the blood flow image 320 can be appropriately displayed based on the speed of the blood flow. That is, in the blood flow image 320, it is possible to achieve both the display of a slow blood flow and the non-display of clutter, and while separating the slow blood flow and clutter, it is possible to ensure the validity of the speed of the displayed blood flow.

[0077] Note that the above-described embodiment can be variously modified. For example, when determining the accuracy of being a blood flow, in addition to the speed information and direction information of the moving body, the dispersion information of the moving body may also be additionally used. For example, when the dispersion is small, it indicates that the phase change is stable, so it can be said that there is a high possibility that it is the blood flow of a blood vessel without pulsation. It is also possible to use such information when determining the accuracy of being a blood flow.

[0078] According to at least one of the embodiments described above, it is possible to generate a blood flow image in which a slow blood flow is also displayed while suppressing clutter. Also, the validity of the speed of the blood flow displayed in the blood flow image can be ensured.

[0079] Note that the term "processor" used in the above description means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a circuit such as an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The processor realizes its functions by reading and executing the programs stored in the storage circuit. Instead of storing the programs in the storage circuit, the programs may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading and executing the programs incorporated in the circuit. Note that the processor is not limited to being configured as a single circuit of the processor, and a plurality of independent circuits may be combined to be configured as one processor to realize its functions. Further, a plurality of components may be integrated into one processor to realize its functions.

[0080] As described above, several embodiments have been described, but these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel devices and methods described in this specification can be implemented in various other forms. Also, various omissions, substitutions, and changes can be made to the forms of the devices and methods described in this specification without departing from the gist of the invention. The scope of the appended claims and equivalents thereof are intended to include such forms and modifications within the scope and gist of the invention.

Explanation of Reference Numerals

[0081] 1 Ultrasonic probe 2 Display 3 Input device 10 Device body 100 Ultrasonic diagnostic device 101 Transmission / reception circuit 102 Buffer memory 103 B-mode processing circuit 104 Doppler processing circuit 105 Output interface 106 Input interface 107 Image generation circuit 108 Display control circuit 109 Image memory 110 Memory circuit 111 Control circuit 112 NW interface 131 Power WF function 132 Power estimation function 133 Blood flow possibility determination function 141 Velocity / direction WF function 142 Autocorrelation processing function 143 Velocity / direction estimation function 151 Packing function 200 External device

Claims

1. An acquisition unit that acquires reflected wave ultrasonic data from a moving object, A first filter processing unit that extracts velocity information of the moving object by applying a first filter to the reflected wave ultrasonic data, A determination unit that determines the probability that the moving object is blood flow based on the reflected wave ultrasonic data and outputs probability information, A blood flow image generation unit that generates a blood flow image based on the velocity information of the moving object extracted by the first filter processing unit and the probability information output by the determination unit, An ultrasonic diagnostic apparatus comprising the above.

2. A second filter processing unit that extracts intensity information regarding the moving object by applying a second filter to the reflected wave ultrasonic data, comprising, The determination unit determines the probability that the moving object is blood flow based on the intensity information, The ultrasonic diagnostic apparatus according to Claim 1.

3. The determination unit determines that the higher the intensity of the intensity information, the higher the probability that it is blood, The ultrasonic diagnostic apparatus according to Claim 2.

4. The blood flow image generation unit generates a blood flow image such that the higher the probability that it is blood flow, the higher the brightness, and the lower the probability that it is blood flow, the lower the brightness, The ultrasonic diagnostic apparatus according to any one of Claims 1 to 3.

5. The blood flow image generation unit does not express the difference in velocity in the velocity information of the moving object as a difference in brightness. The ultrasonic diagnostic apparatus according to Claim 4.

6. The blood flow image generation unit generates a blood flow image using a color map in which the first axis indicates the probability that it is blood flow and the second axis indicates the velocity of the moving object. The ultrasonic diagnostic apparatus according to Claim 5.

7. The ultrasonic diagnostic apparatus according to claim 6, wherein the first filter processing unit applies the first filter to the reflected wave ultrasonic data to extract not only the velocity information of the moving object but also direction information.

8. In the color map, a first color is assigned to a moving object moving in a direction approaching the ultrasonic probe, a second color is assigned to a moving object moving in a direction away from the ultrasonic probe, and a third color is assigned to a moving object whose moving speed is zero. Then, the first color, the second color, and the third color are color-matched so as to gradually change based on the accuracy of being blood flow and the speed of the moving object. The ultrasonic diagnostic apparatus according to claim 7.

9. In the color map, a first color is assigned to a moving object whose moving speed is zero, and a second color is assigned to the maximum value on the color map regarding the speeds of a moving object moving in a direction approaching the ultrasonic probe and a moving object moving in a direction away from the ultrasonic probe, respectively. Then, as the speed of the moving object moving in a direction approaching the ultrasonic probe increases, it is color-matched to change to the second color via a third color, and as the speed of the moving object moving in a direction away from the ultrasonic probe increases, it is color-matched to change to the second color via a fourth color. The ultrasonic diagnostic apparatus according to claim 7.

10. The first filter is a fixed-length wall filter in the Doppler frequency space. The second filter is a wall filter of the eigenvalue expansion type. The ultrasonic diagnostic apparatus according to claim 2.

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