JP7130352B2 - Ultrasound diagnostic equipment and medical image processing equipment - Google Patents

Description

An embodiment of the present invention relates to an ultrasonic diagnostic apparatus and a medical image processing apparatus.

Ultrasound diagnostic equipment radiates ultrasound pulses generated from an ultrasound transducer built into an ultrasound probe into the subject, and receives reflected waves from the subject's tissue with the ultrasound transducer to obtain image data, etc. is generated and displayed.

As one of diagnostic imaging support methods using an ultrasonic diagnostic apparatus, for example, the Doppler method for imaging blood flow using the Doppler effect is known. In the color Doppler method, which is widely used, ultrasound is transmitted and received multiple times on the same scanning line, and by applying an MTI (Moving Target Indicator) filter to the data string at the same position, stationary tissue can be detected. Alternatively, signals derived from slow-moving tissues (clutter signals) are suppressed and signals derived from blood flow are extracted. In the color Doppler method, blood flow information such as blood flow velocity, blood flow variance, and blood flow power is estimated from this blood flow signal, and the distribution of the estimated results is displayed, for example, two-dimensionally in color. Display the image (color Doppler image).

Further, as an image diagnostic support method using an ultrasonic diagnostic apparatus, for example, elastography is known, which measures the hardness of a tissue as one of the tissue properties of a living tissue and visualizes the distribution of the measured hardness. . In elastography, stress is applied to living tissue by methods such as compressing and releasing the biological tissue from the body surface with an ultrasonic probe, or applying acoustic radiation force from the body surface with an ultrasonic probe. Information on internal tissue strain (strain) is generated as an elastic image and displayed.

Note that the blood flow image and the elasticity image can be superimposed on a tomographic image (B-mode image) generated from substantially the same cross section as the image, or can be displayed side by side.

Republished WO2011/099410 JP 2012-110527 A JP-A-08-299342 JP 2014-158698 A Japanese Patent Application Laid-Open No. 2004-351062 JP 2009-195613 A JP 2008-284287 A

A problem to be solved by the present invention is to provide an ultrasonic diagnostic apparatus and a medical image processing apparatus capable of generating a composite image that appropriately expresses blood flow and tissue properties.

An ultrasonic diagnostic apparatus according to an embodiment includes an acquisition unit, an image generation unit, and a synthesis unit. The acquisition unit acquires blood flow information including values representing blood flow at each position within the subject and values representing tissue properties at each position within the subject based on results of ultrasonic scanning of the subject. Acquire tissue characterization information including The image generation unit generates a first image in which the difference in the blood flow information values is expressed at least by a difference in hue, and a second image in which the difference in the tissue attribute information values is expressed by a difference other than the hue. Generate. The synthesizing unit generates a synthesized image by synthesizing the first image and the second image.

FIG. 1 is a block diagram showing a configuration example of an ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example of a signal processing circuit according to the first embodiment; FIG. 3 is a diagram illustrating an example of a scan sequence according to the first embodiment; FIG. 4A is a diagram for explaining processing of an image generation function according to the first embodiment; FIG. 4B is a diagram for explaining processing of an image generation function according to the first embodiment; FIG. 5 is a diagram for explaining the processing of the composition function according to the first embodiment. FIG. 6 is a diagram for explaining the processing of the composition function according to the first embodiment. FIG. 7 is a flow chart showing the processing procedure of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 8A is a diagram for explaining processing of an image generation function according to the second embodiment; FIG. 8B is a diagram for explaining processing of an image generation function according to the second embodiment; FIG. 9 is a diagram for explaining the processing of the composition function according to the second embodiment. FIG. 10 is a block diagram showing a configuration example of a signal processing circuit according to the third embodiment. FIG. 11 is a diagram for explaining processing of the cross-correlation arithmetic circuit according to the third embodiment. FIG. 12 is a diagram for explaining processing of the control circuit according to the fourth embodiment. FIG. 13 is a diagram showing an example of a scan sequence according to another embodiment. FIG. 14 is a block diagram showing a configuration example of a medical image processing apparatus according to another embodiment.

An ultrasonic diagnostic apparatus and a medical image processing apparatus according to embodiments will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration example of an ultrasonic diagnostic apparatus 1 according to the first embodiment. As shown in FIG. 1, the ultrasonic diagnostic apparatus 1 according to the first embodiment includes an apparatus main body 100, an ultrasonic probe 101, an input device 102, and a display 103. The ultrasonic probe 101 , the input device 102 and the display 103 are each connected to the device body 100 .

The ultrasonic probe 101 is brought into contact with the body surface of the subject P to transmit and receive ultrasonic waves (ultrasonic scanning). For example, the ultrasonic probe 101 is a 1D array probe (probe) having a plurality of piezoelectric transducers arranged one-dimensionally in a predetermined direction. These piezoelectric vibrators generate ultrasonic waves based on drive signals supplied from a transmission circuit 110 of the apparatus main body 100, which will be described later. The generated ultrasonic waves are reflected by an acoustic impedance mismatching surface in the subject and received by a plurality of piezoelectric transducers as reflected wave signals including components scattered by scattering bodies in the tissue. The ultrasonic probe 101 sends reflected wave signals received by the plurality of piezoelectric transducers to the transmission circuit 110 .

In this embodiment, a case where a 1D array probe is used as the ultrasonic probe 101 will be described, but the present invention is not limited to this. For example, the ultrasonic probe 101 may be a 2D array probe in which a plurality of piezoelectric transducers are arranged two-dimensionally in a grid pattern, or a 2D array probe in which a plurality of piezoelectric transducers arranged in a one-dimensional manner are mechanically oscillated to produce a three-dimensional array. Any form of ultrasound probe may be used, such as a mechanical 4D probe that scans a dimensional space.

The input device 102 has a mouse, a keyboard, buttons, panel switches, a touch command screen, a foot switch, a trackball, a joystick, etc., and accepts various setting requests from the operator of the ultrasonic diagnostic apparatus 1 and sends them to the apparatus main body 100. and forwards various setting requests received to it.

The display 103 displays a GUI (Graphical User Interface) for the operator of the ultrasonic diagnostic apparatus 1 to input various setting requests using the input device 102, and displays ultrasonic image data generated in the apparatus main body 100. to display.

The device main body 100 is a device that generates ultrasonic image data based on reflected wave signals received by the ultrasonic probe 101 . As shown in FIG. 1, the apparatus body 100 includes, for example, a transmission circuit 110, a reception circuit 120, a signal processing circuit 130, an image processing circuit 140, an image memory 150, a storage circuit 160, and a control circuit 170. have Transmission circuit 110, signal processing circuit 130, image processing circuit 140, image memory 150, storage circuit 160, and control circuit 170 are communicably connected to each other.

The transmission circuit 110 controls transmission of ultrasonic waves by the ultrasonic probe 101 . For example, the transmission circuit 110 applies a drive signal (driving pulse) to the ultrasonic probe 101 at a timing given with a predetermined transmission delay time for each transducer based on an instruction from the control circuit 170, which will be described later. Accordingly, the transmission circuit 110 transmits an ultrasonic beam in which ultrasonic waves are focused into a beam shape.

The receiving circuit 120 controls reception of a reflected wave signal that is the transmitted ultrasonic wave reflected by tissue in the body. For example, the receiving circuit 120 gives a predetermined delay time to the reflected wave signal received by the ultrasonic probe 101 and performs addition processing based on an instruction from the control circuit 170, which will be described later. Thereby, the reflection component from the direction corresponding to the reception directivity of the reflected wave signal is emphasized. Then, the receiving circuit 120 converts the reflected wave signal after addition processing into an in-phase signal (I signal, I: In-phase) and a quadrature signal (Q signal, Q: Quadrature-phase) in the baseband band. Then, the receiving circuit 120 sends the I signal and the Q signal (hereinafter referred to as IQ signal) to the signal processing circuit 130 as reflected wave data. Note that the receiving circuit 120 may convert the reflected wave signal after addition processing into an RF (Radio Frequency) signal and then send the RF (Radio Frequency) signal to the signal processing circuit 130 . The IQ signal and RF signal are signals (reflected wave data) containing phase information.

The signal processing circuit 130 performs various signal processing on the reflected wave data generated from the reflected wave signal by the receiving circuit 120 . For example, the signal processing circuit 130 performs morphological information based on the morphology of structures within the subject, blood flow information based on blood flow within the subject, and elasticity information based on tissue elasticity within the subject through processing described below. Generate information.

FIG. 2 is a block diagram showing a configuration example of the signal processing circuit 130 according to the first embodiment. As shown in FIG. 2 , the signal processing circuit 130 includes a B-mode processing circuit 131 , a Doppler arithmetic processing circuit 132 and a strain distribution arithmetic circuit 133 .

The B-mode processing circuit 131 performs logarithmic amplification, envelope detection processing, etc. on the reflected wave data to obtain data (B-mode data). The B-mode processing circuit 131 sends the generated B-mode data to the image processing circuit 140 . B-mode data is an example of tomographic information and morphological information.

The Doppler arithmetic processing circuit 132 generates data (Doppler data) in which motion information based on the Doppler effect of a mobile object within the scanning range is extracted for each sample point by frequency-analyzing velocity information from the reflected wave data. Specifically, the Doppler arithmetic processing circuit 132 generates Doppler data by extracting average velocity, dispersion value, power value, etc. at each of a plurality of sample points as motion information of the moving object. Here, the moving body is, for example, blood flow, tissue such as a heart wall, and a contrast agent. The Doppler arithmetic processing circuit 132 according to the present embodiment obtains the motion information of the blood flow (blood flow information) such as the average velocity of the blood flow, the average dispersion value of the blood flow, the average power value of the blood flow, and the like at a plurality of sample points. Generate estimated information for each. That is, the blood flow information is information including values based on blood flow (values representing blood flow) at each sample point.

As shown in FIG. 2, the Doppler arithmetic processing circuit 132 includes an MTI (Moving Target Indicator) filter 132A, a blood flow information generating circuit 132B, and a tissue movement velocity generating circuit 132C.

The MTI filter 132A and the blood flow information generation circuit 132B calculate blood flow information by the color Doppler method. In the color Doppler method, transmission and reception of ultrasonic waves are performed multiple times on the same scanning line, and by applying the MTI filter 132 to the data string at the same position, it is possible to obtain images derived from stationary or slow-moving tissues. The signal derived from the blood flow is extracted by suppressing the signal (clutter signal). Then, in the color Doppler method, blood flow information such as blood flow velocity, blood flow variance, and blood flow power is estimated from this blood flow signal.

Specifically, the MTI filter 132A uses a filter matrix to suppress clutter components and extract a blood flow signal derived from blood flow from a data string of continuous reflected wave data at the same position (same sample point). output the data string. The blood flow information generation circuit 132B performs calculation such as autocorrelation calculation using the data output from the MTI filter 132A, estimates blood flow information, and outputs the estimated blood flow information.

As the MTI filter 132A, for example, a Butterworth type IIR (Infinite Impulse Response) filter, a filter with fixed coefficients such as a polynomial regression filter (Polynomial Regression Filter), or an eigenvector or the like is used for the input signal. An adaptive filter can be applied that changes the coefficients accordingly.

The tissue movement velocity generation circuit 132C also performs a Tissue Doppler Imaging (TDI) method for displaying the spatial distribution of information about tissue motion to generate elasticity information representing tissue elasticity. In the TDI method, as in the color Doppler method, transmission and reception of ultrasonic waves are performed multiple times on the same scanning line. The point of calculation is different from the color Doppler method. The generated tissue movement velocity information is converted by the strain distribution arithmetic circuit 133 into elasticity information representing tissue elasticity.

In other words, the tissue moving speed generation circuit 132C performs a calculation such as an autocorrelation calculation on a data string of continuous reflected wave data at the same position (without going through the MTI filter 132A) to obtain a tissue moving speed representing the tissue moving speed. Outputs movement speed information (organizational motion information). Then, based on the tissue movement velocity information, the strain distribution calculation circuit 133 calculates the displacement by time-integrating the movement velocity after the start of deformation of the tissue, and spatially differentiates the displacement to calculate the strain of the tissue. Strain data to represent is calculated as elastic information. Although the case where the TDI method is used to generate elasticity information has been described here, the present invention is not limited to this. For example, the TDI method may output the generated tissue velocity information itself to image the spatial distribution of tissue velocity. Elasticity information is an example of tissue characterization information including values (values representing tissue characterization) based on tissue characterization (hardness) at each position in the subject. Also, the MTI filter 132A is an example of a clutter removal filter.

In this manner, the signal processing circuit 130 performs various signal processing on the reflected wave data by the B-mode processing circuit 131, the Doppler arithmetic processing circuit 132, and the strain distribution arithmetic processing circuit 133, thereby obtaining morphological information and blood flow information. , and to generate elasticity information. Specifically, the signal processing circuit 130 applies a clutter removal filter that removes clutter components to a received data string obtained by a plurality of times of ultrasonic wave transmission/reception at the same position. Get the blood flow information from the data string. Further, the signal processing circuit 130 acquires tissue characterization information from the received data string before application of the clutter removal filter. Also, the tissue characterization information is acquired based on a correlation operation between a plurality of received data including the received data used to acquire the blood flow information.

Note that FIG. 2 is merely an example. For example, a blood flow signal removal filter for removing signals derived from blood flow may be arranged in front of the tissue moving speed generating circuit 132C. That is, the tissue moving speed generation circuit 132C applies a blood flow signal removal filter to the data string of reflected wave data, and generates tissue moving speed information from the data string after application. The blood flow signal removal filter is, for example, a low-pass filter that removes frequency components corresponding to blood flow signals.

Further, the signal processing circuit 130 according to the first embodiment performs the color Doppler method and the TDI method on the same ultrasonic scanning result to generate blood flow information and elasticity information from the same data string.

FIG. 3 is a diagram illustrating an example of a scan sequence according to the first embodiment; In FIG. 3, the horizontal axis corresponds to time. Also, the ultrasonic scans of each frame include a first ultrasonic scan and a second ultrasonic scan.

As shown in FIG. 3, in each frame, a first ultrasound scan and a second ultrasound scan are performed. Here, the first ultrasonic scan is a scan in which transmission and reception of ultrasonic waves are performed a plurality of times (the number of ensembles) on the same scanning line. The signal processing circuit 130 performs the color Doppler method and the TDI method on the result of the first ultrasound scan, thereby generating blood flow information and elasticity information from the same data string. Specifically, the signal processing circuit 130 applies the MTI filter 132A to the data string of the reflected wave data obtained by the first ultrasound scan of the nth frame, and performs calculation such as autocorrelation calculation. to generate blood flow information. Further, calculation such as autocorrelation calculation is performed on the data string of the reflected wave data obtained by the first ultrasonic scan of the n-th frame, without passing through the MTI filter 132A, to generate tissue movement velocity information. do. The second ultrasonic scan is a scan in which transmission and reception of ultrasonic waves are performed once for each scanning line. Signal processing circuitry 130 produces morphological information from the results of the second ultrasound scan.

Thus, the signal processing circuitry 130 produces blood flow information and elasticity information from the results of the same ultrasound scan. In the first embodiment, the blood flow information and the elasticity information are generated from the same ultrasonic scanning result because the clutter signal is small and the reflected wave data capable of generating the tissue strain information is collected. Because it is done. That is, even if the operator does not vibrate the ultrasonic probe 101 positively, strain information can be generated based on the weak vibration generated by the action of bringing the ultrasonic probe 101 into contact with the body surface. For this reason, the reflected wave data collected without actively vibrating the ultrasonic probe 101 contains distortion information and less clutter signals derived from the vibration. Elasticity information can be generated.

Note that FIG. 3 is merely an example, and for example, the second ultrasonic scanning does not necessarily have to be performed after the first ultrasonic scanning. Also, for example, blood flow information and elasticity information do not necessarily have to be generated from the same ultrasound scanning result.

Returning to the description of FIG. The image processing circuit 140 performs processing for generating image data (ultrasound image data), various image processing for image data, and the like. For example, the image processing circuit 140 converts (scan converts) the scanning method of the B-mode data (morphological information), the blood flow information, and the elasticity information generated by the signal processing circuit 130 into a data format for display. Thereby, the image processing circuit 140 obtains B-mode image data (morphological image data) representing the morphology of the structure of the subject, blood flow image data representing the movement of blood flow within the subject, and tissue elasticity within the subject. Elasticity image data representing each is generated. The image processing circuit 140 stores generated image data and image data subjected to various image processing in the image memory 150 . The image processing circuit 140 also generates information indicating the display position of each image data, various information for assisting the operation of the ultrasonic diagnostic apparatus, incidental information related to diagnosis such as patient information, together with the image data, and stores them in the image memory. 150 may be stored.

Also, the image processing circuit 140 according to the first embodiment executes an acquisition function 141 , an image generation function 142 and a synthesizing function 143 . Here, each processing function executed by the acquisition function 141, the image generation function 142, and the synthesis function 143, which are components of the control circuit 170, is recorded in the storage circuit 160 in the form of a computer-executable program, for example. there is The image processing circuit 140 is a processor that reads out each program from the storage circuit 160 and executes it, thereby realizing functions corresponding to each program. That is, the acquisition function 141 is a function realized by the image processing circuit 140 reading and executing a program corresponding to the acquisition function 141 from the storage circuit 160 . Also, the image generation function 142 is a function realized by the image processing circuit 140 reading out a program corresponding to the image generation function 142 from the storage circuit 160 and executing the program. Also, the synthesizing function 143 is a function realized by the image processing circuit 140 reading out a program corresponding to the synthesizing function 143 from the storage circuit 160 and executing it. In other words, the image processing circuit 140 with each program read has each function shown in the image processing circuit 140 of FIG. Each function of the acquisition function 141, the image generation function 142, and the composition function 143 will be described later.

In FIG. 1, the processing functions performed by the acquisition function 141, the image generation function 142, and the composition function 143 are realized by a single image processing circuit 140, but a plurality of independent processors may be used. A processing circuit may be configured by combining them, and functions may be realized by executing programs by each processor.

The term "processor" used in the above description is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC)), a programmable logic device (for example , Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA)). The processor realizes its functions by reading and executing the programs stored in the memory circuit. Note that instead of storing the program in the memory circuit 160, the program may be configured to be directly installed in the circuit of the processor. In this case, the processor implements its functions by reading and executing the program embedded in the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize its function. good. Furthermore, a plurality of components in FIG. 1 may be integrated into one processor to realize its functions.

The image memory 150 is a memory that stores image data (B-mode image data, blood flow image data, elasticity image data, etc.) generated by the image processing circuit 140 . The image memory 150 can also store data generated by the signal processing circuit 130 . The B-mode data, blood flow information, and elasticity information stored in the image memory 150 can be called up by the operator after diagnosis, for example, and can be processed into an ultrasonic image for display via the image processing circuit 140. data.

The storage circuit 160 stores control programs for transmitting and receiving ultrasonic waves, image processing, and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), various data such as diagnostic protocols and various body marks. . The storage circuit 160 is also used for storing image data stored in the image memory 150 as necessary. Data stored in the storage circuit 160 can be transferred to an external device via an interface section (not shown).

The control circuit 170 controls the entire processing of the ultrasonic diagnostic apparatus 1 . Specifically, the control circuit 170 controls the transmission circuit 110, reception circuit 120, It controls processing of the signal processing circuit 130, the image processing circuit 140, and the like. The control circuit 170 also causes the display 103 to display the ultrasound image data stored in the image memory 150 .

The transmitting circuit 110, the receiving circuit 120, the signal processing circuit 130, the image processing circuit 140, the control circuit 170, etc. built into the apparatus main body 100 are processors (CPU (Central Processing Unit), MPU (Micro-Processing Unit) , an integrated circuit, etc.), or may be configured by a program modularized in terms of software.

By the way, a blood flow image or an elasticity image is combined with a corresponding B-mode image for display. Specifically, by superimposing a blood flow image or an elasticity image on a corresponding position on a B-mode image, visibility is improved, which contributes to improvement in accuracy of diagnosis and reduction in diagnosis time.

However, simply synthesizing does not necessarily improve the visibility. For example, since a blood flow image and an elasticity image are generally colored and displayed, if the two are superimposed, the visibility may rather deteriorate. Specifically, the blood flow image is colored with “red-blue” depending on the direction of the blood flow. In addition, the elastic image is colored with a gradation that changes continuously from "blue-green-red" depending on the degree (magnitude) of strain. Therefore, when a blood flow image and an elasticity image are superimposed with a predetermined degree of transparency, it is possible to distinguish, for example, whether a "red" pixel indicates the direction of blood flow or indicates the degree of distortion. Instead, the visibility is lowered. Such a decrease in visibility cannot be solved by adjusting the transmittance of both or dividing the imaging area.

Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment has the disclosed configuration in order to generate a composite image that appropriately expresses blood flow and tissue properties.

The acquisition function 141 acquires B-mode data (morphological information), blood flow information, and elasticity information based on the results of ultrasonic scanning of the subject. For example, acquisition function 141 acquires B-mode data, blood flow information, and elasticity information generated by signal processing circuit 130 . The acquisition function 141 then sends the acquired B-mode data, blood flow information, and elasticity information to the image generation function 142 . Note that the acquisition function 141 is an example of an acquisition unit. Also, elasticity information is an example of tissue characterization information.

Although the case where the acquisition function 141 acquires B-mode data, blood flow information, and elasticity information has been described here, the embodiment is not limited to this. For example, the acquisition function 141 may acquire information other than the above information (for example, incidental information, etc.). Also, for example, the acquisition function 141 does not necessarily acquire the above information. For example, if the B-mode data is not used in the following processing, the acquisition function 141 may not acquire the B-mode data. In this case, the acquisition function 141 acquires blood flow information and elasticity information from the signal processing circuit 130 .

The image generating function 142 generates a B-mode image representing the morphology of structures in the subject P, and a blood flow image in which differences in blood flow information values are expressed by different hues, based on the results of ultrasonic scanning of the subject P. , and an elasticity image in which the difference in the value of elasticity information is expressed in grayscale. Note that the image generation function 142 is an example of an image generation unit.

4A and 4B are diagrams for explaining the processing of the image generation function 142 according to the first embodiment. FIG. 4A illustrates an elasticity image 10 generated by the image generation function 142 . Further, FIG. 4B illustrates a blood flow image 20 generated by the image generation function 142. As shown in FIG. The dashed line in FIG. 4B indicates that the position is associated with the elasticity image 10 in FIG. 4A and is not actually displayed on the blood flow image 20 .

As shown in FIG. 4A, for example, the image generation function 142 converts the scanning method of elasticity information generated by the signal processing circuit 130 into a data format for display. The data converted here is data in which the values representing the strain of the tissue at each sample point of the elasticity information are replaced with the pixel values of each pixel of the display image. Then, the image generation function 142 assigns a color according to the pixel value to each pixel in the converted data according to a color lookup table (LUT) for elasticity images. In this elastic image color LUT, grayscale colors are set according to pixel values. In other words, the image generation function 142 displays the difference in each pixel value in the elasticity image in grayscale. As an example, the image generation function 142 generates the elasticity image 10 by assigning dark gray to hard portions (portions with small strain) and light gray to soft portions (portions with large strain). .

Note that FIG. 4A is merely an example, and for example, the elastic image 10 may be represented by a color LUT in which a single color is assigned to grayscale. In other words, the elasticity image 10 is represented by elements other than hue among the three elements of color (hue, lightness, and saturation). That is, the difference in the value of the elasticity image 10 is represented by the difference in any one of brightness, saturation, and a combination of brightness and saturation. When the elasticity image 10 is expressed in a single color, it is preferable from the standpoint of visibility that the elasticity image 10 is expressed in a color different from the hue of the blood flow image 20 described later (a color that is not close in color space).

Also, as shown in FIG. 4B, the image generation function 142 converts the scanning method of the blood flow information generated by the signal processing circuit 130 into a data format for display. The data converted here is data obtained by replacing the value representing the blood flow at each sample point of the blood flow information with the pixel value of each pixel of the display image. Then, the image generating function 142 assigns a color according to the pixel value to each pixel in the converted data according to the blood flow image color LUT. Here, in the color LUT for the blood flow image, colors including different hues (color temperatures) are set according to pixel values. In other words, the image generation function 142 displays the difference in each pixel value in the blood flow image in hue. As an example, when the power of blood flow is imaged as blood flow information, the image generation function 142 assigns dark red to portions with high power and bright red to portions with low power. Thus, a blood flow image 20 is generated.

Note that FIG. 4B is merely an example, and for example, the blood flow image 20 may be expressed in hues other than red. In addition, the blood flow image 20 may be expressed in red-based and blue-based colors according to the direction of the blood flow. Further, when displaying the velocity component and dispersion component of the blood flow, two different color components may be used. may be represented by a two-dimensional color change using . In other words, the blood flow image 20 is represented by at least the difference in hue among the three elements of color (hue, lightness, and saturation). That is, the difference in the value of the blood flow image 20 is expressed by any one of the hue, the combination of hue and brightness, the combination of hue and saturation, and the combination of hue, brightness and saturation. .

In this way, the image generation function 142 generates the blood flow image 20 in which the difference in the blood flow information value is expressed at least by the difference in hue, and the elasticity image in which the difference in the elasticity information value is expressed by the difference other than the hue. Generate image 10 .

The combining function 143 generates a combined image by combining the blood flow image 20 and the elasticity image 10 . For example, the combining function 143 generates a combined image by superimposing the blood flow image 20 on the corresponding position on the elasticity image 10 . Note that the synthesizing function 143 is an example of a synthesizing unit.

5 and 6 are diagrams for explaining the processing of the synthesizing function 143 according to the first embodiment. FIG. 5 illustrates a synthesized image 30 obtained by synthesizing the elasticity image 10 of FIG. 4A and the blood flow image 20 of FIG. 4B. FIG. 6 illustrates a display image 40 generated using the synthesized image 30. As shown in FIG.

As shown in FIG. 5, the synthesizing function 143 superimposes the blood flow image 20 on the elasticity image 10 to generate a synthetic image 30 . Here, since the elasticity image 10 and the blood flow image 20 are image data generated from the results of the same ultrasonic scanning, the sample points (pixels) of both image data correspond to each other. That is, the synthesizing function 143 superimposes the blood flow image 20 on the corresponding position on the elasticity image 10 without aligning both image data.

Specifically, the synthesizing function 143 extracts a blood flow region from the blood flow image 20 . For example, the synthesizing function 143 recognizes a region having Doppler information (for example, a region having a power value equal to or greater than a threshold value) in the blood flow image 20 as a blood flow region, and cuts out an image of the recognized blood flow region. In the example of FIG. 4B, the synthesizing function 143 cuts out four shaded regions as blood flow regions. Then, the synthesizing function 143 generates the synthesized image 30 by superimposing the cut-out image of the blood flow region on the corresponding position on the elasticity image 10 . The image of the blood flow region superimposed here may be transmitted with a predetermined transparency. Also, in the example of FIG. 5, the case of using a power image as an example of the blood flow image 20 has been described, but the present invention is not limited to this, and a velocity image or a dispersion image may be used, for example.

Further, as shown in FIG. 6, the combining function 143 combines the combined image 30 and the B-mode images 41A and 41B to generate the display image 40 to be displayed on the display 103. FIG. Specifically, the display image 40 is divided into areas in which B-mode images 41A and 41B, which are the same tomographic images, are displayed on the left and right sides.

Specifically, the combining function 143 non-transparently superimposes the combined image 30 on the corresponding position on the B-mode image 41A. This position is determined, for example, based on the position of each sample point in the first ultrasound scan and the second ultrasound scan. By superimposing the synthetic image 30 on the B-mode image 41A in a non-transmissive manner in this way, it is possible to prevent the luminance component of the B-mode image 41A from being mixed in the area of the synthetic image 30, thereby preventing the visibility from deteriorating. .

Further, the synthesizing function 143 displays a B-mode image 41B identical to the B-mode image 41A side by side next to the B-mode image 41A on which the synthesized image 30 is superimposed. Further, the synthesizing function 143 displays a frame line 42 corresponding to the range of the synthetic image 30 on the B-mode image 41B. By displaying the frame line 42, it is possible to easily view the state of the B-mode image (tomographic image) corresponding to the range of the composite image 30, so that comparative observation of the composite image 30 and the B-mode image 41B is facilitated. .

Thus, the synthesizing function 143 generates the display image 40. FIG. The display image 40 generated by the synthesizing function 143 is displayed on the display 103 by the control circuit 170 .

Note that FIG. 6 is merely an example. For example, FIG. 6 illustrates a case where no other image is superimposed on the B-mode image 41B, but the embodiment is not limited to this. For example, the elasticity image 10 or the blood flow image 20 may be superimposed on the corresponding position on the B-mode image 41 with a predetermined transparency. Further, for example, the synthesizing function 143 may output the synthesized image 30 itself as the display image 40, or may output, as the display image 40, an image in which the synthesized image 30 is non-transmissively superimposed on the B-mode image 41A. may Further, for example, the synthesizing function 143 may display, as the display image 40, an image in which the B-mode image 41B is arranged next to the synthesized image 30. FIG. That is, the display image 40 includes at least the composite image 30, and can be generated by appropriately combining other images corresponding in position.

Further, for example, in FIG. 6, the case of displaying the two B-mode images 41A and 41B side by side has been described. Parallel display is possible in various forms such as display, simultaneous display on different display devices, and the like. Also, the images displayed in parallel may be three or more images. When three images are displayed in parallel, two of the images are set as the B-mode image 41A and one image is set as the B-mode image 41B. Alternatively, the synthesized image 30 may be superimposed on the B-mode image 41B without being superimposed on the B-mode image 41A.

FIG. 7 is a flow chart showing the processing procedure of the ultrasonic diagnostic apparatus 1 according to the first embodiment. The processing procedure shown in FIG. 7 is started, for example, by receiving an instruction from the operator to start capturing the composite image 30 while the ultrasonic probe 101 is in contact with the body surface of the subject P. .

In step S101, the ultrasonic diagnostic apparatus 1 starts imaging. For example, the control circuit 170 starts photographing the composite image 30 when an instruction to start photographing the composite image 30 is received from the operator. It should be noted that if step S101 is negative, the control circuit 170 does not start imaging and is in a standby state.

If step S101 is affirmative, the ultrasonic probe 101 performs ultrasonic scanning on the subject P in step S102. For example, the ultrasound probe 101 performs a first ultrasound scan and a second ultrasound scan for each frame (see FIG. 3).

In step S103, the signal processing circuit 130 generates morphological information, blood flow information, and elasticity information. For example, the B-mode processing circuit 131 performs logarithmic amplification, envelope detection processing, and the like on the reflected wave data collected by the second ultrasound scan to generate B-mode data. The Doppler arithmetic processing circuit 132 also applies a clutter removal filter to the received data string acquired by the first ultrasound scan to generate blood flow information from the received data string. Further, the strain distribution calculation circuit 133 calculates the displacement by time-integrating the moving speed after the start of deformation of the tissue based on the tissue moving speed information acquired from the received data string before application of the clutter removal filter. , and spatially differentiate the displacement to generate elastic information.

In step S104, the image processing circuit 140 generates morphological image data, blood flow image data, and elasticity image data. For example, acquisition function 141 acquires B-mode data, blood flow information, and elasticity information generated by signal processing circuitry 130 . Then, the image generation function 142 converts (scan converts) the scanning method of the B-mode data, the blood flow information, and the elasticity information acquired by the acquisition function 141 into a data format for display, thereby generating B-mode image data. , blood flow image data, and elasticity image data, respectively. In the blood flow image data generated here, the difference in values of the blood flow information is expressed at least by the difference in hue, and the elasticity image data is expressed in gray scale.

In step S105, the combining function 143 generates combined image data. For example, the combining function 143 generates the combined image 30 by superimposing the blood flow image 20 on the corresponding position on the elasticity image 10 . The synthesizing function 143 then synthesizes the display image 40 including the generated synthetic image 30 (see FIG. 6).

In step S<b>106 , the control circuit 170 displays the composite image data generated by the image processing circuit 140 on the display 103 . For example, the control circuit 170 displays the display image 40 including the composite image 30 shown in FIG.

In step S107, the control circuit 170 determines whether or not an instruction to end imaging has been received from the operator. Here, if step S107 is negative, the control circuit 170 proceeds to the process of step S102. That is, the ultrasonic diagnostic apparatus 1 performs ultrasonic scanning for the next frame, generates and displays the synthesized image 30 for the next frame.

If step S107 is affirmative, the ultrasonic diagnostic apparatus 1 ends the processing for generating and displaying the composite image 30 . Note that FIG. 7 is merely an example. For example, the procedures described above do not necessarily have to be performed in the order described above. For example, the above steps S101 to S107 may be executed in an appropriate order as long as the processing content is consistent.

As described above, in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the acquisition function 141 acquires blood flow information and tissue characterization information based on the results of ultrasonic scanning of the subject. The image generation function 142 generates a blood flow image in which differences in blood flow information values are expressed at least by differences in hue, and tissue characterization images in which differences in tissue characterization information values are expressed by differences other than hues. do. The synthesizing function 143 generates a synthesized image by synthesizing the blood flow image and the tissue characterization image. Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment can generate a composite image that appropriately expresses blood flow and tissue properties.

For example, the ultrasound diagnostic apparatus 1 acquires the elasticity image 10 and the blood flow image 20 in the same ultrasound scan, that is, in the same cross section. Therefore, the ultrasonic diagnostic apparatus 1 can accurately superimpose the two images, and is expected to improve diagnostic accuracy. The elasticity image 10 and the blood flow image 20 are often used together depending on the clinical department and examination type, and are particularly useful.

In addition, since the ultrasonic diagnostic apparatus 1 reduces the number of ultrasonic scans performed in each frame, the frame rate is improved. In addition, the ultrasonic diagnostic apparatus 1 does not need to switch imaging modes for individually acquiring the elasticity image 10 and the blood flow image 20, and as a result, diagnosis time can be reduced.

Also, in the ultrasonic diagnostic apparatus 1, the image generation function 142 generates a morphological image, a blood flow image, and a tissue characterization image based on the results of ultrasonic scanning of the subject. Then, the control circuit 170 causes the display 103 to display a display image including the synthesized image 30 obtained by synthesizing the blood flow image and the tissue property image and a display image including the morphological image 41B side by side. Thereby, the ultrasonic diagnostic apparatus 1 can simultaneously view the morphological image, the blood flow image, and the tissue characterization image without impairing the visibility.

(Second embodiment)
In the first embodiment, when synthesizing the blood flow image 20 and the elasticity image 10, the blood flow image 20 rendered in hue and the elasticity image 10 rendered in monochromatic color gradation (for example, grayscale) are combined. Although the case of synthesizing is described, the embodiment is not limited to this. For example, the ultrasonic diagnostic apparatus 1 may synthesize a blood flow image drawn with a single color gradation and an elasticity image drawn with hues. Therefore, in the second embodiment, a case will be described in which the ultrasonic diagnostic apparatus 1 synthesizes a blood flow image rendered with a single color gradation and an elasticity image rendered with hues.

The ultrasonic diagnostic apparatus 1 according to the second embodiment has a configuration similar to that of the ultrasonic diagnostic apparatus 1 illustrated in FIG. Therefore, in the second embodiment, the points of difference from the first embodiment will be mainly described, and the description of the points having the same functions as those of the configuration described in the first embodiment will be omitted.

The image generation function 142 according to the second embodiment includes an elasticity image in which the difference in the value of the elasticity information is expressed at least by the difference in hue, and a difference in the value of the blood flow information is expressed by the difference other than the hue. Generate a blood flow image.

8A and 8B are diagrams for explaining the processing of the image generation function 142 according to the second embodiment. FIG. 8A illustrates an elasticity image generated by the image generation function 142. FIG. Further, FIG. 8B illustrates a blood flow image generated by the image generation function 142. As shown in FIG. Note that the dashed line in FIG. 8B indicates that the position of the elasticity image in FIG. 8A is associated with the line, and is not actually displayed on the blood flow image.

As shown in FIG. 8A, for example, the image generation function 142 converts the scanning method of elasticity information generated by the signal processing circuit 130 into a data format for display. Then, the image generation function 142 assigns a color according to the pixel value to each pixel in the converted data according to a color lookup table (LUT) for elasticity images. Here, colors including different hues (color temperatures) are set in the elasticity image color LUT according to pixel values. That is, the image generation function 142 assigns a gradation that changes continuously from "blue-green-red" as the hardness (distortion) changes from a small value (soft) to a large value (hard). An elasticity image 50 is generated.

Also, as shown in FIG. 8B, the image generation function 142 converts the scanning method of the blood flow information generated by the signal processing circuit 130 into a data format for display. Then, the image generation function 142 assigns a gray scale according to the pixel value to each pixel in the converted data according to the blood flow image color LUT. In other words, when the blood flow power is imaged as the blood flow information, the image generation function 142 uses a gray scale image in which the luminance changes as the power changes from a small value (soft) to a large value (hard). A blood flow image 60 is generated by assigning .

A combining function 143 according to the second embodiment generates a combined image 70 by superimposing an elasticity image 50 on a blood flow image 60 .

FIG. 9 is a diagram for explaining the processing of the synthesizing function 143 according to the second embodiment. As shown in FIG. 9, for example, the synthesizing function 143 extracts the blood flow region from the blood flow image 60, and fills the region other than the extracted blood flow region with a predetermined luminance (for example, black). The synthesizing function 143 then superimposes the elasticity image 50 on the blood flow image 60 in which the region other than the blood flow region is filled with a predetermined transparency (transparency that allows the underlying blood flow image 60 to be viewed). Thus, a composite image 70 is generated. As a result, a composite image 70 with a clear blood flow region is obtained.

Note that the synthesizing function 143 may extract a blood flow region from the blood flow image 60 and superimpose the extracted blood flow region on the elasticity image 50 to generate the synthetic image 70 . Here, when assigning a monochromatic color gradation to the blood flow image 60 , it is preferable not to approach the hue of the color LUT of the elasticity image 50 .

As described above, the ultrasonic diagnostic apparatus 1 according to the second embodiment synthesizes the blood flow image 60 rendered with a monochromatic color gradation and the elasticity image 50 rendered with hues to obtain a synthesized image 70 to generate As a result, the ultrasonic diagnostic apparatus 1 according to the second embodiment can generate a composite image that appropriately expresses blood flow and tissue properties.

(Third embodiment)
In the first and second embodiments described above, the case of generating an elasticity image using the TDI method has been described, but the embodiments are not limited to this. For example, the ultrasonic diagnostic apparatus 1 may generate elasticity images based on correlation calculations between adjacent frames. Therefore, in the third embodiment, a case will be described in which the ultrasonic diagnostic apparatus 1 generates elasticity images based on correlation calculations between adjacent frames.

The ultrasonic diagnostic apparatus 1 according to the third embodiment has the same configuration as the ultrasonic diagnostic apparatus 1 illustrated in FIG. Therefore, in the third embodiment, the points of difference from the first embodiment will be mainly described, and the description of the points having the same functions as those of the configuration described in the first embodiment will be omitted.

FIG. 10 is a block diagram showing a configuration example of the signal processing circuit 130 according to the third embodiment. As shown in FIG. 10 , the signal processing circuit 130 includes a B-mode processing circuit 131 , a strain distribution computing circuit 133 , a Doppler computing circuit 134 and a cross-correlation computing circuit 135 . Note that the B-mode processing circuit 131 and the strain distribution computing circuit 133 are the same as the B-mode processing circuit 131 and the strain distribution computing circuit 133 shown in FIG. 2, so description thereof will be omitted.

Similar to the Doppler arithmetic processing circuit 132 illustrated in FIG. 2, the Doppler arithmetic processing circuit 134 includes an MTI filter 132A and a blood flow information generating circuit 132B, but does not include a tissue moving velocity generating circuit 132C. The MTI filter 132A and the blood flow information generation circuit 132B are the same as the MTI filter 132A and the blood flow information generation circuit 132B shown in FIG. 2, so description thereof will be omitted. That is, the Doppler arithmetic processing circuit 134 generates blood flow information by substantially the same processing as the Doppler arithmetic processing circuit 132 .

A cross-correlation calculation circuit 135 generates tissue displacement information based on the reflected wave data from the reception circuit 120 . This tissue displacement information is information that is input to the strain distribution arithmetic circuit 133 that generates elasticity information.

FIG. 11 is a diagram for explaining the processing of the cross-correlation calculation circuit 135 according to the third embodiment. FIG. 11 illustrates a scan sequence similar to that of FIG. That is, also in the third embodiment, a scan sequence similar to the scan sequence of the first embodiment shown in FIG. 3 is executed.

Here, the cross-correlation calculation circuit 135 calculates the cross-correlation (or phase difference) of the IQ signal (or RF signal) at the same position between adjacent frames, thereby representing tissue displacement between the frames. Generate displacement information. Specifically, as indicated by arrows in FIG. 11, the cross-correlation calculation circuit 135 acquires IQ signals from the first ultrasound scans performed in the n-th frame and the n+1-th frame, respectively. Then, the cross-correlation calculation circuit 135 calculates the cross-correlation of the IQ signals at the same position between the n-th frame and the n+1-th frame, thereby generating tissue displacement information between these frames. The strain distribution calculation circuit 133 then spatially differentiates the tissue displacement generated by the cross-correlation calculation circuit 135 to calculate elasticity information.

In this way, the Doppler arithmetic processing circuit 134 can generate elasticity information (tissue property information) based on correlation arithmetic between received data between adjacent frames. The elasticity information (elasticity image) generated using the received data of the nth frame and the (n+1)th frame is displayed simultaneously with the tomographic image and the blood flow image generated from the received data of the nth or (n+1)th frame. This makes it possible to simultaneously display information on substantially the same cross section at substantially the same time.

(Fourth embodiment)
In the fourth embodiment, a case will be described in which ultrasonic scanning is performed at a higher frame rate than in the first to third embodiments described above.

For example, in the configurations described in the first to third embodiments, in order to improve the performance of the MTI filter 132A, it is necessary to increase the number of data strings (packets) of reflected wave data obtained by ultrasonic scanning of each frame. is preferred. However, in this case, the frame rate decreases as the packet size increases. Therefore, in the fourth embodiment, a configuration for increasing the frame rate will be described.

In the acquisition of blood flow information (and elasticity information), the control circuit 170 according to the fourth embodiment performs ultrasonic scanning within the scanning range in a scanning mode capable of acquiring reflected wave data at the same position over a plurality of frames. Execute repeatedly. In addition, for the collection of tomographic information, the control circuit 170 executes partial ultrasonic scanning by dividing the scanning range over a plurality of frames while switching the divided range. That is, the control circuit 170 performs partial ultrasonic scanning in which the scanning range is divided while switching the divided range between ultrasonic scanning of blood flow information repeatedly performed over a plurality of frames.

FIG. 12 is a diagram for explaining the processing of the control circuit 170 according to the fourth embodiment. “B” shown in FIG. 12 indicates a range in which ultrasonic scanning is performed using the transmission/reception conditions for B mode. That is, the range in which B-mode ultrasonic scanning is performed is divided into four divided ranges (first divided range to fourth divided range). "D" shown in FIG. 12 indicates the range in which ultrasonic scanning is performed using the transmission/reception conditions for the color Doppler mode. For example, "D" shown in FIG. 12 is the range in which ultrasonic scanning is performed by the above high frame rate method. That is, in the ultrasonic scanning illustrated in FIG. 12, unlike the general color Doppler method, ultrasonic waves are transmitted multiple times in the same direction and reflected waves are received multiple times. Sound waves are transmitted and received once. The control circuit 170 performs ultrasonic wave transmission/reception once for each of a plurality of scanning lines forming a scanning range as ultrasonic scanning for color Doppler mode, and acquires blood flow information using reflected waves for a plurality of frames. An ultrasound scan based on the method (high frame rate method) is performed.

First, the control circuit 170 performs B-mode ultrasound scanning on the first divided range (see (1) in FIG. 12), and performs color Doppler mode ultrasound scanning on the scanning range of one frame. Acoustic scanning is performed (see (2) in FIG. 12). Then, the control circuit 170 performs B-mode ultrasound scanning on the first divided range (see (3) in FIG. 12), and color Doppler mode ultrasound scanning on the scanning range of one frame. Acoustic scanning is performed (see (4) in FIG. 12). Then, the control circuit 170 causes B-mode ultrasound scanning to be performed on the first divided range (see (5) in FIG. 12), and color Doppler mode ultrasound scanning on the scanning range of one frame. Acoustic scanning is performed (see (6) in FIG. 12). Then, the control circuit 170 causes B-mode ultrasound scanning to be performed on the first divided range (see (7) in FIG. 12), and color Doppler mode ultrasound scanning on the scanning range for one frame. Acoustic scanning is performed (see (8) in FIG. 12).

Here, as exemplified in FIG. 12, the control circuit 170 sets the intervals at which ultrasonic scanning for the color Doppler mode is performed to be equal intervals. That is, "point X" on the scanning range is scanned once each by ultrasonic scanning of (2), (4), (6) and (8) in FIG. It is controlled to be "T". Specifically, the control circuit 170 equalizes the time required for each divided scanning performed in the B-mode ultrasonic scanning, and sets the interval at which the ultrasonic scanning for the color Doppler mode is performed at equal intervals. For example, the control circuit 170 ensures that the time required for the divided scans of the B-mode ultrasonic scans performed in (1), (3), (5), and (7) of FIG. 12 is always the same. Control. The control circuit 170 sets the size of each divided range, the number of scanning lines, the scanning line density, the depth, etc., to be the same. For example, if the number of scanning lines is the same, the time required for each divided scanning of the B-mode ultrasonic scanning is the same. The signal processing _{circuit 130 performs a} , correlation calculation, etc. are performed, and blood flow information and elasticity information of "point X" are output.

Thus, the ultrasonic diagnostic apparatus 1 according to the fourth embodiment can perform ultrasonic scanning at a high frame rate. For this reason, the ultrasonic diagnostic apparatus 1 generates blood flow information and elasticity information in a frame period for forming one tomographic image, and performs imaging and display of the information, thereby performing almost the same time and at almost the same time. Information on the same cross section can be displayed simultaneously.

(Other embodiments)
Various different forms may be implemented in addition to the embodiments described above.

(when morphological, perfusion, and elasticity images are generated by different ultrasound scans)
In the above embodiments, for example, a case where a blood flow image and an elasticity image are generated by the same ultrasound scan has been described, but embodiments are not limited to this. For example, morphological images, blood flow images, and elasticity images may be generated by different ultrasound scans.

FIG. 13 is a diagram showing an example of a scan sequence according to another embodiment. In FIG. 13, the horizontal axis corresponds to time. Also, the ultrasound scans of each frame include a first ultrasound scan, a second ultrasound scan, and a third ultrasound scan. Here, the first ultrasonic scan and the second ultrasonic scan are the same as those shown in FIG. That is, a blood flow image (blood flow information) is generated from the first ultrasound scan, and a morphological image (morphological information) is generated from the second ultrasound scan.

A third ultrasound scan is now performed to generate an elasticity image (elasticity information). In this case, for example, the signal processing circuit 130 generates tissue moving velocity information by the TDI method from the reflected wave data obtained by the third ultrasonic scan, and calculates elasticity information. Alternatively, the signal processing circuit 130 may generate an elasticity image based on a correlation calculation between adjacent frames.

(Application of shear wave elastography)
Further, in the above embodiment, a case where an elastic image is generated by strain elastography, which visualizes strain caused by weak vibrations generated by the action of bringing the ultrasonic probe 101 into contact with the body surface, is described. However, embodiments are not limited to this. For example, by applying an acoustic radiation force (push pulse) from the body surface to the living tissue to generate displacement based on shear waves, and observing the displacement at each point in the scanning cross section over time, shear waves can be generated. Shearwave elastography, which derives the elastic modulus from the propagation velocity of , may be applied.

Ultrasonic scanning when shear wave elastography is applied will be described with reference to FIG. 13 . In this case, the first ultrasound scan and the second ultrasound scan are the same as described above. That is, a blood flow image (blood flow information) is generated from the first ultrasound scan, and a morphological image (morphological information) is generated from the second ultrasound scan.

Here, the third ultrasonic scanning is ultrasonic scanning for generating an elasticity image (elasticity information) by shear wave elastography. However, in shear wave elastography, a shear wave generated by one push pulse transmission attenuates as it propagates, so one region of interest is divided into a plurality of small regions and scanned. FIG. 13 illustrates a case where the region of interest is divided into three small regions and scanned, and the elasticity images of the three small regions are synthesized to obtain one elasticity image corresponding to the region of interest. Here, for convenience of explanation, the three sub-regions are denoted as sub-regions A, B, and C. FIG.

That is, in the n-th frame, a blood flow image is generated from the first ultrasonic scan, a morphological image is generated from the second ultrasonic scan, and an elasticity image of the small region A is generated from the third ultrasonic scan. be. Subsequently, in the n+1th frame, a blood flow image is generated from the first ultrasonic scan, a morphological image is generated from the second ultrasonic scan, and an elasticity image of the small region B is generated from the third ultrasonic scan. be done. Then, in the n+2th frame, a blood flow image is generated from the first ultrasonic scan, a morphological image is generated from the second ultrasonic scan, and an elasticity image of the small region C is generated from the third ultrasonic scan. be. By synthesizing the elasticity images of the small regions A, B, and C, one elasticity image corresponding to the region of interest can be generated. In other words, elasticity images generated by shearwave elastography have a lower frame rate depending on the number of small regions compared to blood flow images and morphological images. The elastic image generated by shear wave elastography is similar to the elastic image generated by strain elastography described in the above embodiment, except that the frame rate is low. available for display.

(Other tissue characterization images)
In addition to the elasticity image described above, images such as attenuation images, ASQ (acoustic structure quantification) mode images, and microcalcification-enhanced images can also be applied as tissue property images.

Here, the attenuation image is an image of the state of attenuation of ultrasonic waves propagating in the living body. For example, the attenuation of ultrasonic waves is estimated from the signal strength of a reflected wave signal obtained by transmitting and receiving ultrasonic waves of a predetermined frequency.

The ASQ mode image is obtained by obtaining the degree of deviation (variance value) of the signal amplitude distribution of the received signal from the Rayleigh distribution by statistical filtering, and converting the variance value into an image.

A microcalcification-enhanced image is obtained by extracting microcalcifications generated in a tissue to be observed from a B-mode image and imaging the extracted microcalcifications.

When the attenuation image, the ASQ mode image, and the microcalcification-enhanced image are combined with the blood flow image as the tissue characterization image, the blood flow image is expressed by the difference in hue, and the tissue characterization image is expressed by the difference other than the hue. It is preferred to express

(medical image processing device)
Also, the processing described in the above embodiments may be executed in a medical image processing apparatus.

FIG. 14 is a block diagram showing a configuration example of a medical image processing apparatus according to another embodiment. As shown in FIG. 14, the medical image processing apparatus 200 includes an input device 201, a display 202, a memory circuit 210, and a processing circuit 220.

The input device 201 has a mouse, a keyboard, buttons, panel switches, a touch command screen, a foot switch, a trackball, a joystick, etc., receives various setting requests from the operator of the medical image processing apparatus 200, and receives various settings. Transfer the request to each processing unit.

The display 202 displays a GUI for the operator of the medical image processing apparatus 200 to input various setting requests using the input device 201, and displays information generated in the medical image processing apparatus 200 and the like.

The memory circuit 210 is a semiconductor memory device such as a flash memory, or a nonvolatile memory device such as a hard disk or an optical disk.

The processing circuit 220 is an integrated circuit such as an ASIC or FPGA, or an electronic circuit such as a CPU or MPU, and controls the overall processing of the medical image processing apparatus 200 .

The processing circuitry 220 also performs an acquisition function 221 , an image generation function 222 and a composition function 223 . The acquisition function 221, the image generation function 222, and the synthesizing function 223 have the same functions as the acquisition function 141, the image generation function 142, and the synthesizing function 143 described in the above embodiments, respectively.

That is, the acquisition function 221 acquires blood flow information and tissue characterization information. The image generating function 222 extracts blood flow information obtained by the obtaining function 221 from the blood flow information obtained by the obtaining function 221. The blood flow information values including the values based on the blood flow at each position in the subject are represented by at least different hues. A stream image 20 is generated. In addition, the image generation function 222 expresses, from the tissue characterization information acquired by the acquisition function 221, differences in values of the tissue characterization information including values based on the tissue characterization at each position in the subject by differences other than hue. An elasticity image 10 is generated. Then, the image generation function 222 stores the generated blood flow image 20 and elasticity image 10 in the storage circuit 210 . Then, the synthesizing function 223 generates a synthesized image 30 by synthesizing the blood flow image 20 and the elasticity image 10 .

Note that the medical image processing apparatus 200 may acquire the generated blood flow image 20 and elasticity image 10 from the modality and synthesize the acquired images. In this case, the acquisition function 221 acquires the blood flow image 20 and the elasticity image 10 from each modality, and stores the acquired blood flow image 20 and elasticity image 10 in the storage circuit 210 . Then, the synthesizing function 223 generates a synthesized image 30 by synthesizing the blood flow image 20 and the elasticity image 10 .

Further, FIG. 14 describes the case where the synthetic image 30 is generated by synthesizing the blood flow image 20 and the elasticity image 10, but the synthetic image 70 is generated by synthesizing the blood flow image 60 and the elasticity image 50. may

Also, each component of each device illustrated is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution and integration of each device is not limited to the illustrated one, and all or part of them can be functionally or physically distributed and integrated in arbitrary units according to various loads and usage conditions. Can be integrated and configured. Furthermore, each processing function performed by each device may be implemented in whole or in part by a CPU and a program analyzed and executed by the CPU, or implemented as hardware based on wired logic.

Further, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or the processes described as being performed manually can be performed manually. can also be performed automatically by known methods. In addition, information including processing procedures, control procedures, specific names, and various data and parameters shown in the above documents and drawings can be arbitrarily changed unless otherwise specified.

Further, the medical image processing method described in the above embodiments can be realized by executing a prepared medical image processing program on a computer such as a personal computer or a workstation. This medical image processing program can be distributed via a network such as the Internet. In addition, the medical image processing program may be recorded on a computer-readable recording medium such as a hard disk, flexible disk (FD), CD-ROM, MO, DVD, etc., and may be executed by being read from the recording medium by a computer. can.

According to at least one embodiment described above, it is possible to generate a composite image that appropriately expresses blood flow and tissue properties.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

1 Ultrasonic Diagnostic Apparatus 140 Image Processing Circuit 141 Acquisition Function 142 Image Generation Function 143 Synthesis Function

Claims (12)

blood flow information including values representing blood flow at each position within the subject, tissue property information including values representing tissue properties at each position within the subject, based on the results of ultrasonic scanning of the subject; and an acquisition unit that acquires morphological information including a value representing the morphology at each position in the subject;
A first image in which the difference in the value of the blood flow information is expressed in a non-grayscale using a first color, and a second color in which the difference in the value of the tissue attribute information is different from the first color. to generate a second image expressed in non-grayscale using and a third image in which the difference in the value of the morphological information is expressed in grayscale . an image generator in which the first image and the second image are represented by different elements ;
a combining unit configured to generate a combined image by combining the first image, the second image, and the third image;
An ultrasound diagnostic device. The image generation unit generates a first image in which the difference in the blood flow information value is represented by at least a difference in hue; The difference in the values of the tissue characterization information is at leastMomo Akiradifference in intensity or saturationcomeExpressed second strokethe statuegenerateRu
Claim 1 Ultrasound diagnostic equipment. The image generation unit generates a second image in which the difference in the values of the tissue characterization information is represented by at least a difference in hue, and a second image in which the difference in the values of the blood flow information is represented by at least a difference in brightness or saturation . 1 generate an image,
The ultrasonic diagnostic apparatus according to claim 1. The difference in the values of the tissue characterization information is expressed as a difference in any one of hue, a combination of hue and brightness, a combination of hue and saturation, and a combination of hue, brightness and saturation,
The difference in the value of the blood flow information is expressed as a difference in any one of brightness, saturation, and a combination of brightness and saturation.
The ultrasonic diagnostic apparatus according to claim 2. The acquisition unit acquires the blood flow information and the tissue characterization information from the same ultrasound scanning results.
The ultrasonic diagnostic apparatus according to any one of claims 1 to 4. Further comprising a control unit for displaying an image on the display unit,
The synthesizing unit superimposes the first image on the second image in a transparent state, and superimposes the second image on which the first image is superimposed on the third image in a non-transparent state. to generate a first display image,
The control unit causes the display unit to display the first display image,
The ultrasonic diagnostic apparatus according to any one of claims 1 to 5. The control unit causes the display unit to display a second display image including the third image side by side with the first display image.
The ultrasonic diagnostic apparatus according to claim 6. The acquisition unit
A clutter removal filter that removes clutter components is applied to a reception data string obtained by transmitting and receiving ultrasonic waves at the same position a plurality of times, and the blood flow information is obtained from the reception data string after applying the clutter removal filter. ,
obtaining the tissue characterization information from the received data string before applying the clutter removal filter;
The ultrasonic diagnostic apparatus according to any one of claims 1 to 7. The tissue property information is elasticity information obtained based on a correlation operation between a plurality of pieces of received data including the received data used to obtain the blood flow information, and represents tissue hardness .
The ultrasonic diagnostic apparatus according to any one of claims 1 to 7. Blood flow information including values representing blood flow at each position within the subject, tissue including values representing tissue properties at each position within the subject, acquired based on results of ultrasonic scanning of the subject A first image in which a difference in values of the blood flow information is expressed in a non-grayscale using a first color, with respect to the morphological information including the property information and a value representing the morphology at each position in the subject ; A second image in which the differences in the values of the tissue characterization information are expressed in non-grayscale using a second color different from the first color, and a grayscale image in which the differences in the values of the morphological information are expressed in grayscale. a storage unit that stores a third image represented by a scale , wherein the first image and the second image are represented by different elements among the three elements of hue, brightness, and saturation ;
a combining unit configured to generate a combined image by combining the first image, the second image, and the third image;
A medical image processing apparatus comprising: an acquisition unit that acquires the blood flow information, the tissue characterization information, and the morphological information;
generating the first image, the second image, and the third image from the blood flow information, the tissue characterization information, and the morphological information acquired by the acquisition unit, and generating the first image; 11. The medical image processing apparatus according to claim 10, further comprising: an image generation unit that stores said second image and said third image in said storage unit. an acquisition unit that acquires the first image, the second image, and the third image, respectively, and stores the acquired first image, the second image, and the third image in the storage unit; The medical image processing apparatus according to claim 10.

Images