JP6979854B2 - Ultrasonic diagnostic equipment and its control program - Google Patents

Description

The present invention is an ultrasonic diagnostic apparatus for displaying a motion image by creating a signal derived from motion in a subject such as blood flow based on an ultrasonic echo signal transmitted to the subject. Regarding the control program.

Examples of the motion image showing motion information in the subject such as blood flow include a color Doppler image and a B flow image. In these color Doppler images and B-flow images, artifacts called flash artifacts may occur due to the influence of pulsation, body movement, or respiration. In addition, the operator cannot keep the ultrasonic probe stationary on the body surface and moves it, which also causes a flash artifact.

Flash artifact is a phenomenon in which information on movements such as pulsation, body movement, respiration, and movement of an ultrasonic probe is displayed on an image in addition to the blood flow that is originally desired to be observed, which hinders the observation of blood flow. Therefore, a method for removing such a flash artifact is disclosed in, for example, Patent Documents 1 and 2.

Japanese Unexamined Patent Publication No. 4-256740 Japanese Unexamined Patent Publication No. 2012-19917

By the way, for example, in the scan section of an ultrasonic wave including a large blood vessel (carotid artery, etc.), both the blood flow signal and the signal intensity of the flash due to the pulsation of the blood vessel are high, and in the scan of the thyroid gland slightly away from the carotid artery, Both the blood flow signal and the signal strength of the flash are slightly weakened. In this way, it is considered that the signal strength of the flash frame to be removed differs depending on the observation target. In addition, there are various causes for the occurrence of flash artifacts as described above. For example, flash artifacts due to pulsations occur for a relatively short period of time (small frames), and flash artifacts due to body movements, respiration and movement of an ultrasonic probe take longer than if they occur due to pulsations. Occurs (the number of frames is large). Therefore, it is desirable to appropriately suppress flash artifacts according to the site and the cause of occurrence, and obtain an image with good image quality.

Based on the above-mentioned problems, the inventor of the present application can set appropriate correction information according to the site of the subject and the cause of generating the flash artifact, and can suppress the flash artifact more effectively. Provide a diagnostic device. That is, the invention of one viewpoint made to solve the above-mentioned problems is an ultrasonic diagnostic apparatus including a control device and a display device, and the control device transmits a signal derived from a motion in a subject. A first creation function for creating the motion information of one frame based on the signals of a plurality of frames, a second creation function for creating motion image data indicating the motion information, and the above. A display control function for displaying a motion image on the display device based on motion image data, a representative value calculation function for calculating a representative value representing the signal strength in one frame, and a representative value for a plurality of frames. A statistical value calculation function that calculates statistical values, and a third creation function that creates correction information that corrects the strength of the signal based on the comparison result between the threshold value set based on the statistical values and the representative value. And a correction function for creating a corrected signal by correcting the signal using the correction information is executed by a program, and the first creation function is for the plurality of frames. It is an ultrasonic diagnostic apparatus that creates information on the movement using the corrected signal.

Further, in the invention of the other aspect, in the invention of the above one aspect, the third creation function is the first correction information when the representative value is larger than the threshold value set based on the statistical value. Is created, and when the representative value is smaller than the threshold value, a second correction information different from the first correction information is created, and the first correction information and the second correction information are created. Is created so that the strength of the corrected signal obtained by using the first correction information is smaller than the strength of the corrected signal obtained by using the second correction information. It is an ultrasonic diagnostic device.

According to the invention of the above one aspect, the statistical value of the representative value in a plurality of frames is calculated, and the threshold value set based on the statistical value is compared with the representative value to create the correction information. , Appropriate correction information is created according to the site of the subject. Further, for example, when a pulsation occurs, the intensity of the signal increases, but the statistical value does not fluctuate much because the time is relatively short, and the representative value often becomes larger than the threshold value. .. In this case, the motion image in which the flash artifact is further suppressed by creating the correction information for correcting the intensity of the signal based on the comparison result between the threshold value set based on the statistical value and the representative value. Can be displayed. On the other hand, when body movement, respiration, and movement of the ultrasonic probe occur, the intensity of the signal increases over a longer period of time, so that the statistical value increases. Therefore, the representative value is often smaller than the threshold value. Therefore, the image corresponding to the tissue image as the motion image is created by creating the correction information for correcting the intensity of the signal based on the comparison result between the threshold value set based on the statistical value and the representative value. Can be displayed.

Further, according to the invention of another viewpoint, for example, when a pulsation is generated, the first correction information is created so that the intensity of the signal becomes smaller, so that the motion image in which the flash artifact is suppressed is further suppressed. Can be displayed. On the other hand, when body movement, respiration, and movement of the ultrasonic probe occur, the second correction information is created so that the intensity of the signal becomes higher, and an image corresponding to the tissue image is displayed as the movement image. be able to.

It is a block diagram which shows the schematic structure of the ultrasonic diagnostic apparatus which is an example of embodiment of this invention. It is a functional block diagram which shows the echo data processing part. It is a functional block diagram which shows the display processing part. It is explanatory drawing which shows the concept of the creation of the data of the blood flow information. It is a flowchart which shows the creation of the correction information in the ultrasonic diagnostic apparatus of embodiment. It is explanatory drawing of the calculation of the statistical value of a representative value. It is a figure explaining the creation of the corrected data. It is a figure which shows an example of the time change of the representative value and the threshold value set based on the average value of the representative value. It is a figure which shows the other example of the time change of the representative value and the threshold value set based on the average value of the representative value. It is a figure which shows an example of the setting function of the 1st coefficient corresponding to the number of consecutive frames where FI> Fth. It is a figure which shows the change of the correction coefficient when the representative value shown in FIG. 9 is obtained.

Hereinafter, embodiments of the present invention will be described. The ultrasonic diagnostic apparatus 1 shown in FIG. 1 includes an ultrasonic probe 2, a transmission / reception beam former 3, an echo data processing unit 4, a display processing unit 5, a display device 6, an operation device 7, a control device 8, and a storage device 9. The ultrasonic diagnostic apparatus 1 has a configuration as a computer.

The ultrasonic probe 2 is an example of the embodiment of the ultrasonic probe in the present invention, and transmits ultrasonic waves to a living tissue of a subject and receives an echo signal thereof.

The transmission / reception beam former 3 drives the ultrasonic probe 2 based on the control signal from the control device 8 to transmit ultrasonic waves having a predetermined transmission parameter (parameter). Further, the transmission / reception beam former 3 performs signal processing such as phasing / addition processing on the ultrasonic echo signal. Further, the ultrasonic beam former 3 may perform orthogonal detection processing on the echo signal. A part of the transmission / reception beam former 3 may be functionally realized by the control device 8 reading and executing the program.

As shown in FIG. 2, the echo data processing unit 4 includes a B mode processing unit 41, a motion information processing unit 42, a representative value calculation unit 43, a statistical value calculation unit 44, a setting unit 45, a correction information creation unit 46, and a correction unit. Has 47. The processing by the B mode processing unit 41, the motion information processing unit 42, the representative value calculation unit 43, the statistical value calculation unit 44, the setting unit 45, the correction information creation unit 46, and the correction unit 47 in the echo data processing unit 4 is, for example, a control device. 8 is functionally realized by reading and executing the program.

The B-mode processing unit 41 performs B-mode processing such as logarithmic compression processing and envelope detection processing on the echo data output from the transmission / reception beam former 3 to create B-mode data. The B mode processing unit 41 outputs the B mode data to the display processing unit 5.

The motion information processing unit 42 creates a signal derived from the motion in the subject based on the echo data output from the transmission / reception beam former 3. The motion-derived signal is a signal in which a signal derived from a stationary biological tissue or a slow-moving biological tissue is suppressed. For example, the motion information processing unit 42 performs color Doppler processing on the echo data output from the transmission / reception beam former 3. The color Doppler treatment includes, for example, MTI (Moving Target Indicator) filter treatment and the like. The signal derived from the motion is the signal after the MTI filter processing.

Ideally, it is desirable that the clutter signal and the blood flow signal can be completely separated when the signal derived from the movement is extracted by the MTI filter processing, but in an actual living body, it is due to the steep movement due to the blood vessel wall according to the heartbeat. The clutter signal or the like is a signal having a velocity component closer to that of blood flow, and it is difficult to completely suppress it. Therefore, the signal derived from the movement includes a signal derived from the blood flow and a signal derived from the movement of the living tissue around the blood vessel in response to the heartbeat. Further, the signal derived from the movement includes a signal derived from the relative movement between the ultrasonic probe 2 and the subject, for example, an ultrasonic wave caused by the movement of the subject or the movement of the ultrasonic probe 2. It contains a signal derived from the relative movement between the probe 2 and the subject. Further, the signal derived from the movement includes a signal derived from the movement of the living tissue due to respiration.

Further, the motion information processing unit 42 creates blood flow information data including blood flow velocity, blood flow dispersion, blood flow power, etc. based on the data obtained by performing MTI processing, and color Doppler. It is output to the display processing unit 5 as data. The motion information processing unit 42 compares the threshold value Fth, which will be described later, with the representative value FI, and creates blood flow information data. Details will be described later. The function of the motion information processing unit 42 is an example of the embodiment of the first creation function in the present invention. Further, the blood flow information is an example of the embodiment of the motion information in the present invention.

The representative value calculation unit 43 calculates the representative value FI representing the strength of the signal derived from the movement in one frame obtained by the motion information processing unit 42. Details will be described later. The function of the representative value calculation unit 43 is an example of the embodiment of the representative value calculation function in the present invention.

The statistical value calculation unit 44 calculates the statistical value of the representative value FI in a plurality of frames. Details will be described later. The function of the statistical value calculation unit 44 is an example of the embodiment of the statistical value calculation function in the present invention.

As will be described later, the setting unit 45 sets the threshold value Fth based on the statistical value.

The correction information creation unit 46 creates correction information for correcting the intensity of the signal derived from the movement in the subject based on the comparison result between the threshold value Fth and the representative value FI. The correction information creation unit 46 creates different correction information according to the comparison result between the threshold value Fth and the representative value FI. The correction information creation unit 46 creates the correction information for each frame. The function of the correction information creating unit 46 is an example of the embodiment of the third creating function in the present invention.

The correction unit 47 corrects the signal derived from the movement by using the correction information, and creates a corrected signal. The correction unit 47 creates a corrected signal for each frame. The function of the correction unit 47 is an example of the embodiment of the correction function in the present invention.

As shown in FIG. 3, the display processing unit 5 has an image data creation unit 51 and an image display control unit 52. The processing by the image data creation unit 51 and the image display control unit 52 in the display processing unit 5 is functionally realized by, for example, the control device 8 reading and executing the program.

The image data creation unit 51 creates B-mode image data by scanning and converting the B-mode data with a scan converter. Further, the image data creation unit 51 creates color Doppler image data by scanning and converting the color Doppler data with a scan converter. The function of the image data creating unit 51 is an example of the embodiment of the second creating function in the present invention. Further, the color Doppler image data is an example of the embodiment of the motion image data in the present invention.

The image display control unit 52 causes the display device 6 to display an image in which the color Doppler image is superimposed on the B mode image based on the B mode image data and the color Doppler image data. The function of the image display control unit 52 is an example of the embodiment of the display control function in the present invention. Further, the color Doppler image is an example of the embodiment of the motion image in the present invention.

The display device 6 is an LCD (Liquid Crystal Display), an organic EL (Electro-Luminescence) display, or the like. The display device 6 is an example of an embodiment of the display device in the present invention.

The operation device 7 is a device that receives instructions and input of information from the user. The operation device 7 includes a button and a keyboard (keyboard) for receiving instructions and input of information from the operator, and further includes a pointing device such as a trackball.

The control device 8 is a processor such as a CPU (Central Processing Unit). The control device 8 reads out the program stored in the storage device 9 and controls each part of the ultrasonic diagnostic apparatus 1. The control device 8 is an example of an embodiment of the control device in the present invention.

For example, the control device 8 reads out the program stored in the storage device 9, and causes the functions of the transmission / reception beam former 3, the echo data processing unit 4, and the display processing unit 5 to be executed by the read program. The control device 8 may programmatically execute all the functions of the transmission / reception beam former 3, all the functions of the echo data processing unit 4, and all the functions of the display processing unit 5. Only some functions may be performed programmatically. If the control device 8 performs only some functions, the remaining functions may be performed by hardware such as circuits.

The functions of the transmission / reception beam former 3, the echo data processing unit 4, and the display processing unit 5 may be realized by hardware such as a circuit.

The storage device 9 includes a non-transient storage medium and a transient storage medium. The non-transient storage medium is, for example, a non-volatile storage medium such as an HDD (Hard Disk Drive) and a ROM (Read Only Memory). The non-transient storage medium may include a portable storage medium such as a CD (Compact Disk) or a DVD (Digital Versatile Disc).

The transient storage medium is a volatile storage medium such as RAM (Random Access Memory).

The program executed by the control device 8 is stored in a non-transient storage medium such as an HDD or a ROM constituting the storage device 9. Further, the program may be stored in a portable and non-transient storage medium such as a CD or a DVD constituting the storage device 9.

Next, the operation of the ultrasonic diagnostic apparatus 1 of this example will be described. Based on the echo signal obtained by transmitting and receiving ultrasonic waves, the B mode processing unit 41 creates B mode data, and the motion information processing unit 42 creates color Doppler data.

The creation of color Doppler data will be described. The motion information processing unit 42 performs MTI filter processing on the echo data output from the transmission / reception beam former 3. The echo data to be MTI filtered are the I signal and the Q signal obtained by orthogonal detection.

Further, the motion information processing unit 42 creates blood flow information data based on the data obtained by performing the MTI filter processing. This will be described in detail with reference to FIG. In FIG. 4, the data obtained by performing the MTI filtering process is conceptually illustrated as the first data D1. The first data D1 is an example of a signal derived from motion. Further, the blood flow information data is conceptually illustrated as the second data D2. The first data D1 and the second data D2 are composed of data corresponding to one frame of pixels. The motion information processing unit 42 calculates blood flow information by, for example, an autocorrelation method based on the first data D1 of a plurality of frames, and creates the second data D2 (color Doppler data) of one frame.

Here, the first data D1 in one frame is data based on an echo signal obtained by transmitting and receiving ultrasonic waves once for all sound lines in a region for displaying a color Doppler image. Further, a color Doppler image of one frame is displayed based on the second data D2 of one frame. Therefore, one frame of color Doppler image is displayed based on the echo signal obtained by transmitting and receiving ultrasonic waves for a plurality of frames. The concept of the frame in the first data D1 is a frame for transmitting and receiving ultrasonic waves, unlike a frame for displaying a color Doppler image.

The motion information processing unit 42 uses the corrected data aD1 of a plurality of frames obtained by correcting the first data D1 with the correction information as the first data D1 of the plurality of frames, and uses the corrected data aD1 of a plurality of frames as the second data D2 of one frame. To create. The corrected data aD1 is an example of the corrected signal.

Each time the first data D1 of the latest frame is obtained, the correction unit 47 corrects the first data D1 to create the corrected data aD1. The creation of the corrected data aD1 will be described. First, the correction information creation unit 46 creates correction information for creating the corrected data aD1. The creation of the correction information will be described with reference to the flowchart of FIG. First, in step S1, when the first data D1 in one frame is obtained, the representative value calculation unit 43 calculates the representative value FI representing the signal strength of the first data D1 in that frame. Since the value of the first data D1 indicates the signal strength of the echo signal derived from the motion, for example, the representative value calculation unit 43 sets the representative value FI as the value of the first data D1 corresponding to the pixel of the color Doppler image. Calculate the average value in one frame. As the first data D1 corresponding to the pixel, for example, an I signal and a Q signal can be obtained. Therefore, the representative value calculation unit 43 can obtain, for example, the average value of the sum of squares of the I signal and the Q signal as the average value. The average value of the sum of the absolute values of the I signal and the Q signal may be calculated.

The representative value calculation unit 43 calculates the representative value FI each time the first data D1 of one frame is obtained. The calculated representative value FI is stored in the storage device 9.

Next, in step S2, the statistical value calculation unit 44 calculates the statistical value of the representative value FI in a plurality of frames. The statistical value calculation unit 44 calculates, for example, the average value FIave of the representative value FI in a plurality of frames as the statistical value. As shown in FIG. 6, the statistical value calculation unit 44 calculates the average value FIave using the representative value FI of each of the frames from the latest frame at the time t to the past frame of the required number n. For example, n may be less than or greater than the number of frames (number of packets) of the first data D1 used to create the second data D2, or may be the same. n may be set as a default, or may be set by inputting by the operator on the operating device 7. The statistical value calculation unit 44 may calculate the average value FIave each time the first data D1 of one frame is obtained. The latest frame at time t is an example of an embodiment of the latest frame in the present invention.

When the average value FIave is obtained in step S2, in step S3, the setting unit 45 sets the threshold value Fth based on the average value FIave. Specifically, the setting unit 45 sets Fth based on the following (Equation 1).
Fth = SF x FIave ... (Equation 1)
In (Equation 1), SF is a scale factor and is a desired constant. SF is, for example, an arbitrary value of 1 or more. The scale factor SF and n described above regulate the inhibitory effect of flash artifacts. The scale factor may be set as a default, or may be set by the operator inputting on the operation device 7.

When the threshold value Fth is obtained in step S3, in step S4, the correction information creating unit 46 compares the representative value FI of the latest frame at time t with the threshold value Fth. If the representative value FI is larger than the threshold value Fth (FI> Fth, “YES” in step S4), the process proceeds to step S5. On the other hand, if the representative value FI is equal to or less than the threshold value Fth (FI ≦ Fth, “NO” in step S4), the process proceeds to step S6.

Incidentally, the setting unit 45 may set the threshold value Fth each time the first data D1 of the new frame is obtained, and the correction information creation unit 46 may set the threshold value Fth and the representative of the newly obtained frame. It may be compared with the value FI.

In step S5, the correction information creation unit 46 calculates the first correction coefficient C1 as the correction information. For example, the correction information creation unit 46 calculates the first correction coefficient C1 based on the following (Equation 2).
C1 = k1 / FI ... (Equation 2)
k1 is a required constant larger than 0 and is a first coefficient set to a value at which a color Doppler image of a desired image quality can be obtained. The desired image quality is, for example, an image quality in which flash artifacts are suppressed. For example, the first coefficient k1 is set to a value at which the first correction coefficient C1 having a value close to 0 can be obtained. The first coefficient k1 may be stored in 9 in the storage device. The first coefficient k1 is an example of the embodiment of the first coefficient in the present invention.

Further, in (Equation 2), the FI is a representative value representing the signal strength of the first data D1 in the frame for which the corrected data is to be created, that is, the latest frame.

In step 6, the correction information creation unit 46 calculates the second correction coefficient C2 as the correction information. For example, the correction information creation unit 46 calculates the second correction coefficient C2 based on the following (Equation 3).
C2 = k2 / FI ... (Equation 3)
k2 is a required constant larger than 0 and is a second coefficient set to a value at which a color Doppler image of a desired image quality can be obtained. The desired image quality is, for example, an image quality having information corresponding to a tissue image. Also, k2> k1. The second coefficient k2 may be stored in 9 in the storage device. The second coefficient k2 is an example of the embodiment of the second coefficient in the present invention. The FI is the same as (Equation 2).

The correction information creating unit 46 may set the second correction coefficient C2 to 1 when the second correction coefficient C2 obtained in (Equation 2) exceeds 1.

Since k2> k1, the first correction coefficient C1 and the second correction coefficient C2 have different values. Specifically, since the representative value FI representing the signal strength of the first data D1 is a value of 1 or more (FI ≧ 1), C1 <C2. As a result, the signal strength of the corrected data aD1 of the latest frame obtained by using the first correction coefficient C1 is higher than the signal strength of the corrected data aD1 of the latest frame obtained by using the second correction coefficient C2. The first correction coefficient C1 and the second correction coefficient C2 are created so as to be smaller.

When the first correction coefficient C1 or the second correction coefficient C2 is obtained, the correction unit 47 has the first correction coefficient C1 or the first correction coefficient C1 with respect to the first data D1 of the latest frame, as shown in FIG. Corrected data aD1 is created by multiplying the two correction coefficients C2. In the first data D1, the correction unit 47 multiplies each of the data corresponding to the pixels by the first correction coefficient C1 or the second correction coefficient C2.

Although the time axis is omitted in FIG. 7, it is assumed that the time flows from the left to the right as in FIG. Therefore, the first data D1 on the far right is the data of the latest frame.

When the representative value FI is determined to be larger than the threshold value Fth in step S4, the correction unit 47 multiplies the first data D1 of the latest frame by the first correction coefficient C1. On the other hand, when the representative value FI is determined to be equal to or less than the threshold value Fth in step S4, the correction unit 47 multiplies the first data D1 of the latest frame by the second correction coefficient C2. The corrected data aD1 obtained by multiplying the first correction coefficient C1 or the second correction coefficient C2 is stored in the storage device 9.

The motion information processing unit 42 uses the corrected data aD1 obtained for the latest frame and the corrected data aD1 obtained for a plurality of frames retroactively from the latest frame to obtain the second data D2 of one frame. To create.

When the second data D2 is obtained, the image data creation unit 51 creates color Doppler image data based on the second data D2. Further, the image display control unit 52 causes the display device 6 to display an image in which the color Doppler image is superimposed on the B mode image based on the color Doppler image data and the B mode image data.

According to this example, the threshold value is set in consideration of the representative value of the signal strength derived from the movement of a plurality of frames. For example, as shown in FIG. 8, the latest frame is the frame M, and the frames older than the frame M are the frames (M-1), (M-2), (M-3), and (M-4). .. Assuming that the representative values of the respective frames M, (M-1), (M-2), (M-3), and (M-4) are the representative values FI1, FI2, FI3, FI4, and FI5, the frame M The threshold value Fth is calculated based on the representative values of the past n frames including the representative values FI1 to FI5 obtained up to this frame M. Further, the threshold value Fth in the frame (M-1) is calculated based on the representative values of the past n frames including the representative values FI2 to FI5 obtained up to this frame (M-1). The same applies to other frames. As a result, in each frame, the threshold value Fth in which the representative value FI of the past n frames is taken into consideration is obtained. FIG. 8 shows a graph G of the time change of the threshold value Fth.

In FIG. 8, the representative value FI1 is a value larger than the threshold value Fth. Therefore, the first correction coefficient C1 is calculated in step S5. As a result, the corrected data aD1 in the frame M becomes a small value, and the color Doppler image in the frame M becomes an image in which the flash artifact is removed.

As described above, since the threshold value Fth is set based on the representative value FI of the past n frames, the threshold value Fth can be appropriately set according to the site. For example, when displaying a color Doppler image of the carotid artery, which has a stronger signal intensity based on the echo signal of the ultrasonic wave than the thyroid gland, after displaying the color Doppler image of the thyroid gland, the carotid artery is better than the thyroid gland. Since the average FIave is large, the threshold Fth is larger in the carotid artery than in the thyroid gland. As described above, according to this example, the threshold value Fth can be set so that the flash frame is more reliably suppressed depending on the portion, while the frame that is not the flash frame can be displayed.

Further, in FIG. 8, in the frame M alone, the representative value FI is larger than the other frames, and the number of consecutive frames in which the representative value FI is large is small. For example, when the signal derived from the movement includes the signal derived from the beat, the representative value FI becomes large only in a relatively short period of time. Therefore, by creating the corrected data aD1 using the first correction coefficient C1 calculated in step S5, a color Doppler image from which flash artifacts caused by movements that occur in a short time such as pulsations are removed can be obtained. Obtainable.

On the other hand, in FIG. 9, not only the frame M but also the frames (M + 1), (M + 2), (M + 3), and (M + 4) after the frame M have representative values FI6, FI7, FI8, and FI9 as compared with other frames. The value of is increasing. In this case, the average value FIave increases as the number of consecutive frames having a large representative value FI value increases. As a result, the representative values FI8 and FI9 become smaller than the threshold value Fth. Therefore, the second correction coefficient C2 is calculated in step S5. As a result, the corrected data aD1 in the frames (M + 3) and (M + 4) becomes a large value as compared with the case where the first correction coefficient C1 is used.

In FIG. 9, the number of consecutive frames having a large representative value FI is relatively large. Here, when the signal derived from the movement includes a signal caused by the movement of the subject, the movement of the ultrasonic probe, respiration, or the like, the representative value FI becomes large over a relatively long period of time. In this way, when the representative value FI is large over a relatively long period of time, for the purpose of removing flash artifacts, for example, if color Doppler data is created without using the data of the frame having a large representative value FI, the color Doppler image will be displayed. It will not be displayed (blackout). On the other hand, if the flash artifact is not removed, the artifact will cover the entire image and a pure white image will be displayed. However, in this example, since the corrected data aD1 is created by using the second correction coefficient C2 which is larger than the first correction coefficient C1, a color Doppler image having information corresponding to the background tissue image is displayed. be able to.

In FIG. 9, the number of frames having a large representative value FI is only 5 frames for convenience of explanation and space, but may be larger.

Next, a modification of the above embodiment will be described. As shown in FIG. 10, the first coefficient k1 may be set according to the number of consecutive frames in which FI> Fth. In FIG. 10, the horizontal axis represents the number of consecutive frames with FI> Fth (the number of continuous frames), and the vertical axis represents the first coefficient k1 determined according to the number of continuous frames. That is, FIG. 10 shows a setting function f of the first coefficient k1 according to the number of consecutive frames where FI> Fth. The correction information creation unit 46 sets the first coefficient k1 using the setting function f.

The setting function f is a function in which the first coefficient k1 increases as the number of continuous frames increases, and when the number of continuous frames exceeds a required number, the first coefficient k1 becomes a constant value. In this way, the first coefficient k1 continuously changes according to the number of continuous frames, so that the flicker of the color Doppler image can be suppressed. This will be described in more detail with reference to FIG. FIG. 11 shows the change in the correction coefficient C1 when the representative values FI1 to FI9 shown in FIG. 9 are obtained.

In FIG. 11, before the time T1 is reached, it corresponds to the frames (M-4), (M-3), (M-2), and (M-1) in FIG. 9, and the correction coefficient is the second correction. The coefficient C2. Then, the time T1 corresponds to the frame M, and the correction coefficient becomes the first correction coefficient C1 and becomes a value close to 0. After the time T1 and up to the time T2, it corresponds to the frames (M + 1) and (M + 2) in FIG. 9, and the correction coefficient is the first correction coefficient C1 that gradually increases with the passage of time. The portion after the time T2 corresponds to the frame (M + 3), (M + 4) and the frame after the frame (M + 4), which is not shown in FIG. 9, and the correction coefficient becomes the second correction coefficient. ..

In the time between the times T1 and T2 shown in FIG. 11 and other times, there may be more frames than the frames shown in FIG.

From time T1 to time T2, as described above, the correction coefficient is the first correction coefficient C1, but as the number of continuous frames increases with the passage of time, the first coefficient k1 gradually increases. In this way, the first coefficient k1 changes continuously according to the number of continuous frames, so that the correction coefficients are the first correction coefficient C1 and the second, as compared with the case where the first coefficient is constant. It is possible to suppress the flicker of the color Doppler image when switching between the correction coefficient C2 and the correction coefficient C2.

Although the present invention has been described above by the above-described embodiment, it is needless to say that the present invention can be modified in various ways without changing the gist thereof. For example, the representative value FI calculated by the representative value calculation unit 43 is not limited to the average value in one frame of the value of the first data D1 corresponding to the pixel of the color Doppler image. For example, the representative value calculation unit 43 may calculate the sum of the values of the first data D1 corresponding to the pixels of the color Doppler image in one frame instead of the average value as the representative value FI.

Further, the statistical value calculated by the statistical value calculation unit 44 is not limited to the average value FIave. For example, the statistical value calculation unit 44 may calculate the median value of the representative value FI in a plurality of frames as the statistical value. In this case, the setting unit 45 multiplies the median value by the above-mentioned SF to set Fth.

Further, the motion information processing unit 42 performs B flow processing instead of the color Doppler processing to create B flow data, and the display processing unit 5 creates and displays B flow image data based on the B flow data. The B flow image may be displayed on the device 6. The B-flow image is an example of the embodiment of the motion image in the present invention.

1 Ultrasonic diagnostic device 6 Display device 8 Control device 9 Storage device 42 Motion information processing unit 43 Representative value calculation unit 44 Statistical value calculation unit 45 Setting unit 46 Correction information creation unit 47 Correction unit 51 Image data creation unit 52 Image display control unit

Claims (14)

An ultrasonic diagnostic device including a control device and a display device.
The control device is
The first creation function that creates a signal derived from the movement in the subject and creates information on the movement in one frame based on the signal in a plurality of frames.
A second creation function that creates motion image data indicating the motion information, and
A display control function for displaying a motion image on the display device based on the motion image data,
A representative value calculation function that calculates a representative value that represents the strength of the signal in one frame, and
A statistical value calculation function that calculates the statistical value of the representative value in multiple frames, and
A third creation function for creating correction information for correcting the strength of the signal based on the comparison result between the threshold value set based on the statistical value and the representative value, and
A correction function that corrects the signal using the correction information and creates a corrected signal.
Is executed programmatically,
The first creation function is an ultrasonic diagnostic apparatus that creates information on the movement using the corrected signals of the plurality of frames. The ultrasonic diagnostic apparatus according to claim 1, wherein the third creation function creates different correction information according to a comparison result between a threshold value set based on the statistical value and the representative value. The third creation function creates the first correction information when the representative value is larger than the threshold value set based on the statistical value, and when the representative value is smaller than the threshold value, the third creation function is described. The second correction information different from the first correction information is created, and the first correction information and the second correction information are the corrected corrections obtained by using the first correction information. The ultrasonic diagnostic apparatus according to claim 1 or 2, wherein the signal strength is created so as to be smaller than the corrected signal strength obtained by using the second correction information. The third creation function calculates the first correction coefficient as the first correction information when the representative value is larger than the threshold value, and when the representative value is smaller than the threshold value, the second correction function is used. Calculate the second correction coefficient as correction information,
When the representative value is larger than the threshold value, the correction function corrects the signal using the first correction coefficient to create the corrected signal, and the representative value is larger than the threshold value. The ultrasonic diagnostic apparatus according to claim 3, wherein when the value is small, the signal is corrected by using the second correction coefficient to create the corrected signal. The first correction coefficient and the second correction coefficient are numerical values of 1 or less, and the second correction coefficient is a value larger than the first correction coefficient.
The ultrasonic diagnostic apparatus according to claim 4, wherein the correction function creates a corrected signal by multiplying the signal by the first correction coefficient or the second correction coefficient. The third creation function claims that, as the first correction coefficient, a value corresponding to the number of consecutive frames having a representative value larger than the threshold value is set by tracing back from the latest frame to the past frame. Item 4. The ultrasonic diagnostic apparatus according to Item 4. The first correction coefficient is a value obtained by dividing the first coefficient by the representative value, and the second correction coefficient is a second coefficient larger than the first coefficient divided by the representative value. The ultrasonic diagnostic apparatus according to claim 5 or 6, which is a value. One of claims 1 to 7, wherein the statistical value calculation function calculates the statistical value using the representative value of each of the frames from the latest frame to the required number of past frames. The ultrasonic diagnostic apparatus according to paragraph 1. The first creation function is any of claims 1 to 8, wherein the echo signal is filtered to create a signal in which the clutter component is suppressed as a signal derived from the movement. The ultrasonic diagnostic apparatus according to item 1. The ultrasonic diagnostic apparatus according to any one of claims 1 to 9, wherein the motion image data is color Doppler image data. The ultrasonic diagnostic apparatus according to any one of claims 1 to 9, wherein the motion image data is B flow image data. The representative value calculation function is any one of claims 1 to 11, characterized in that the average value or the sum of the values indicating the signal strength corresponding to the pixels of the motion image in one frame is calculated as the representative value. The ultrasonic diagnostic apparatus described in. The ultrasonic diagnostic apparatus according to any one of claims 1 to 12, wherein the statistical value calculation function calculates an average value or a median value of the representative values in a plurality of frames as the statistical values. A control program for an ultrasonic diagnostic device including a control device and a display device.
The control program is applied to the control device.
The first creation function that creates a signal derived from the movement in the subject and creates information on the movement in one frame based on the signal in a plurality of frames.
A second creation function that creates motion image data indicating the motion information, and
A display control function for displaying a motion image on the display device based on the motion image data,
A representative value calculation function that calculates a representative value that represents the strength of the signal in one frame, and
A statistical value calculation function that calculates the statistical value of the representative value in multiple frames, and
A third creation function for creating correction information for correcting the strength of the signal based on the comparison result between the threshold value set based on the statistical value and the representative value, and
A correction function that corrects the signal using the correction information and creates a corrected signal.
To execute,
The first creation function is a control program of an ultrasonic diagnostic apparatus that creates information on the movement using the corrected signals of the plurality of frames.

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