JP2017213474A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a composite image properly expressing blood flow and tissue properties.SOLUTION: An ultrasonic diagnostic apparatus has an acquisition part and a composition part. The acquisition part acquires blood flow information including a value which expresses the blood flow at each position in a first area in a subject on the basis of a result of a first ultrasonic scan to the subject, and acquires tissue properties information including a value which expresses tissue properties at each position in a second area overlapping with the first area on the basis of a result of a second ultrasonic scan to the subject. The composition part generates a composite image by combining a first image based on the blood flow information and a second image based on the tissue properties information. The second ultrasonic scan includes an observation of variation with time by a shear wave at each position in the second area by causing the shear wave to be generated by applying acoustic radiation force to the subject.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an ultrasonic diagnostic apparatus.

  Ultrasonic diagnostic equipment emits ultrasonic pulses generated from an ultrasonic transducer built in an ultrasonic probe into the subject, receives reflected waves from the subject tissue by the ultrasonic transducer, and receives image data, etc. Is generated and displayed.

  As one of image diagnosis support methods using an ultrasonic diagnostic apparatus, for example, a Doppler method for imaging blood flow using the Doppler effect is known. In the widely used color Doppler method, ultrasound transmission / reception is performed a plurality of times on the same scanning line, and an MTI (Moving Target Indicator) filter is applied to a data string at the same position, thereby stationary tissue. Alternatively, a signal derived from blood flow is extracted by suppressing a signal (clutter signal) derived from a slow moving tissue. In the color Doppler method, blood flow information such as blood flow velocity, blood flow dispersion, blood flow power, and the like is estimated from the blood flow signal, and the distribution of the estimation result is, for example, two-dimensionally displayed blood flow Display an image (color Doppler image).

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

  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 displayed in parallel.

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

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

  The ultrasonic diagnostic apparatus according to the embodiment includes an acquisition unit and a synthesis unit. The acquisition unit acquires blood flow information including a value representing a blood flow at each position in the first region in the subject based on a result of the first ultrasonic scan on the subject, and obtains a first blood flow for the subject. Based on the result of two ultrasonic scans, tissue property information including a value representing the tissue property at each position in the second region overlapping the first region is acquired. The synthesizing unit generates a synthesized image by synthesizing the first image based on the blood flow information and the second image based on the tissue property information. The second ultrasonic scan includes generating a shear wave by applying an acoustic radiation force to the subject, and observing a displacement due to the shear wave over time at each position in the second region.

FIG. 1 is a block diagram illustrating a configuration example of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example of the 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 the image generation function according to the first embodiment. FIG. 4B is a diagram for explaining processing of the image generation function according to the first embodiment. FIG. 5 is a diagram for explaining the processing of the combining function according to the first embodiment. FIG. 6 is a diagram for explaining processing of the synthesis function according to the first embodiment. FIG. 7 is a flowchart showing a processing procedure of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 8A is a diagram for explaining processing of the image generation function according to the second embodiment. FIG. 8B is a diagram for explaining processing of the image generation function according to the second embodiment. FIG. 9 is a diagram for explaining the processing of the combining function according to the second embodiment. FIG. 10 is a block diagram illustrating 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 illustrating an example of a scan sequence according to another embodiment. FIG. 14 is a block diagram illustrating a configuration example of a medical image processing apparatus according to another embodiment.

  Hereinafter, an ultrasonic diagnostic apparatus and a medical image processing apparatus according to embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating 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 apparatus main body 100.

  The ultrasonic probe 101 is in contact with the body surface of the subject P, and transmits and receives ultrasonic waves (ultrasonic scanning). For example, the ultrasonic probe 101 is a 1D array probe (probe) having a plurality of piezoelectric vibrators arranged one-dimensionally in a predetermined direction. The plurality of piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from a transmission circuit 110 included in the apparatus main body 100 described later. The generated ultrasonic wave is reflected by the acoustic impedance mismatching surface in the subject, and is received by a plurality of piezoelectric vibrators as a reflected wave signal including a component scattered by a scatterer in the tissue. The ultrasonic probe 101 sends the reflected wave signal received by the plurality of piezoelectric vibrators to the transmission circuit 110.

  In the present 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, as the ultrasonic probe 101, a 2D array probe in which a plurality of piezoelectric vibrators are two-dimensionally arranged in a lattice shape or a plurality of piezoelectric vibrators arranged in a one-dimensional manner are mechanically swung. Any form of ultrasonic probe may be used, such as a mechanical 4D probe that scans a dimensional area.

  The input device 102 includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, and the like, receives various setting requests from an operator of the ultrasonic diagnostic apparatus 1, and The various setting requests received are transferred.

  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, ultrasonic image data generated in the apparatus main body 100, and the like. Is displayed.

  The apparatus main body 100 is an apparatus that generates ultrasonic image data based on a reflected wave signal received by the ultrasonic probe 101. As shown in FIG. 1, the apparatus main 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 The transmission circuit 110, the signal processing circuit 130, the image processing circuit 140, the image memory 150, the storage circuit 160, and the control circuit 170 are connected to each other so as to communicate with 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 (drive pulse) to the ultrasonic probe 101 at a timing when a predetermined transmission delay time is given to each transducer based on an instruction from the control circuit 170 described later. Thereby, the transmission circuit 110 transmits the ultrasonic beam in which the ultrasonic wave is focused in a beam shape.

  The receiving circuit 120 controls reception of a reflected wave signal in which the transmission ultrasonic wave is reflected by the body tissue. For example, the receiving circuit 120 performs addition processing by giving a predetermined delay time to the reflected wave signal received by the ultrasonic probe 101 based on an instruction from the control circuit 170 described later. Thereby, the reflection component from the direction according to the reception directivity of the reflected wave signal is emphasized. Then, the receiving circuit 120 converts the reflected wave signal after the addition processing into a baseband in-phase signal (I signal, I: In-phase) and a quadrature signal (Q signal, Q: Quadrature-phase). Then, the receiving circuit 120 sends an I signal and a 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 the addition processing into an RF (Radio Frequency) signal and send it to the signal processing circuit 130. The IQ signal and the RF signal are signals (reflected wave data) including phase information.

  The signal processing circuit 130 performs various kinds of 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 the processing described below, the form information based on the form of the structure in the subject, the blood flow information based on the blood flow in the subject, and the elasticity based on the tissue elasticity in the subject. Generate information.

  FIG. 2 is a block diagram illustrating 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 calculation processing circuit 132, and a distortion distribution calculation circuit 133.

  The B mode processing circuit 131 performs logarithmic amplification, envelope detection processing, etc. on the reflected wave data, and data (B mode) in which the signal intensity of each of a plurality of sample points (observation points) is expressed by brightness. Data). The B mode processing circuit 131 sends the generated B mode data to the image processing circuit 140. The B mode data is an example of tomographic information and morphological information.

  The Doppler calculation processing circuit 132 generates data (Doppler data) obtained by extracting motion information based on the Doppler effect of the moving object within the scanning range for each sample point by performing frequency analysis on the velocity information from the reflected wave data. Specifically, the Doppler calculation processing circuit 132 generates Doppler data obtained by extracting an average speed, a variance value, a power value, and the like at each of a plurality of sample points as movement information of the moving body. Here, the moving body is, for example, a blood flow, a tissue such as a heart wall, or a contrast agent. The Doppler calculation processing circuit 132 according to the present embodiment uses, as the blood flow motion information (blood flow information), an average velocity of blood flow, an average dispersion value of blood flow, an average power value of blood flow, and the like as a plurality of sample points. Generate information estimated by each. That is, the blood flow information is information including a value based on the blood flow at each sample point (a value representing the blood flow).

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

  The MTI filter 132A and the blood flow information generation circuit 132B calculate blood flow information by a color Doppler method. In the color Doppler method, transmission / reception of ultrasonic waves is performed a plurality of times on the same scanning line, and the MTI filter 132 is applied to the data string at the same position, thereby deriving from a stationary tissue or a slow moving tissue. The signal (clutter signal) to suppress is extracted, and the signal derived from the blood flow is extracted. In the color Doppler method, blood flow information such as blood flow velocity, blood flow dispersion, and blood flow power is estimated from the blood flow signal.

  Specifically, the MTI filter 132A uses a filter matrix to suppress a clutter component 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 calculations 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 filter with fixed coefficients such as a Butterworth type IIR (Infinite Impulse Response) filter, a polynomial regression filter (Polynomial Regression Filter), or an eigenvector is used as an input signal. An adaptive filter that changes the coefficient accordingly can be applied.

  Further, the tissue movement speed generation circuit 132C executes a tissue Doppler (TDI) method for displaying a spatial distribution of information related to tissue motion in order to generate elasticity information representing the elasticity of the tissue. In the TDI method, as in the color Doppler method, transmission / reception of ultrasonic waves is performed a plurality of times on the same scanning line. However, the phase difference of the data string and the tissue movement speed are further reduced without passing through the MTI filter 132A. The point of calculation is different from the color Doppler method. The generated tissue movement speed information is converted by the strain distribution calculation circuit 133 into elasticity information representing the elasticity of the tissue.

  That is, the tissue movement speed generation circuit 132C performs a calculation such as an autocorrelation calculation (without passing through the MTI filter 132A) on a data string of continuous reflected wave data at the same position, and represents a tissue movement speed. Outputs movement speed information (tissue motion information). Based on the tissue movement speed information, the strain distribution calculation circuit 133 calculates the displacement by time-integrating the movement speed after the start of the tissue deformation, and further calculates the displacement by spatially differentiating the displacement. The represented strain data is calculated as elasticity information. Although the case where the TDI method is performed to generate the elasticity information has been described here, the present invention is not limited to this. For example, the TDI method may output the generated tissue movement speed information itself in order to image the spatial distribution of the tissue movement speed. The elasticity information is an example of tissue property information including a value (a value representing the tissue property) based on the tissue property (hardness) at each position in the subject. The MTI filter 132A is an example of a clutter removal filter.

  As described above, the signal processing circuit 130 performs various types of signal processing on the reflected wave data by the B-mode processing circuit 131, the Doppler calculation processing circuit 132, and the distortion distribution calculation circuit 133, so that the morphological information and blood flow information are obtained. , And generate elasticity information. Specifically, the signal processing circuit 130 applies a clutter removal filter that removes a clutter component to a reception data string obtained by performing ultrasonic transmission / reception a plurality of times at the same position, and receives the signal after the clutter removal filter is applied. Blood flow information is acquired from the data string. Further, the signal processing circuit 130 acquires the tissue property information from the received data string before application of the clutter removal filter. Further, the tissue property information is acquired based on a correlation calculation between a plurality of received data including the received data used for acquiring blood flow information.

  FIG. 2 is merely an example. For example, a blood flow signal removal filter for removing a signal derived from blood flow may be arranged in the previous stage of the tissue movement speed generation circuit 132C. That is, the tissue movement speed generation circuit 132C applies a blood flow signal removal filter to the data string of the reflected wave data, and generates tissue movement 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 the blood flow signal.

  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, and generates 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. Further, the ultrasonic scanning of each frame includes a first ultrasonic scanning and a second ultrasonic scanning.

  As shown in FIG. 3, the first ultrasonic scan and the second ultrasonic scan are performed in each frame. Here, the first ultrasonic scanning is scanning in which transmission / reception of ultrasonic waves is performed a plurality of times (number of ensembles) on the same scanning line. The signal processing circuit 130 generates blood flow information and elasticity information from the same data string by performing the color Doppler method and the TDI method on the result of the first ultrasonic scanning. Specifically, the signal processing circuit 130 applies an MTI filter 132A to the data sequence of the reflected wave data obtained by the first ultrasonic scanning of the nth frame, and performs an operation such as an autocorrelation operation. To generate blood flow information. In addition, tissue movement velocity information is generated by performing an autocorrelation operation or the like on the data sequence of the reflected wave data obtained by the first ultrasonic scanning of the nth frame (without passing through the MTI filter 132A). To do. The second ultrasonic scanning is a scan in which transmission / reception of ultrasonic waves is performed once for each scanning line. The signal processing circuit 130 generates morphological information from the result of the second ultrasonic scanning.

  As described above, the signal processing circuit 130 generates blood flow information and elasticity information from the result of the same ultrasonic scanning. In the first embodiment, the blood flow information and the elasticity information are generated from the same ultrasonic scanning result because the reflected wave data is collected with few clutter signals and capable of generating tissue strain information. Because it is done. That is, even if the operator does not actively vibrate the ultrasonic probe 101, distortion 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 positively exciting the ultrasonic probe 101 includes distortion information, and since there are few clutter signals derived from the vibration, blood flow information and Elasticity information can be generated.

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

  Returning to the description of FIG. The image processing circuit 140 performs image data (ultrasound image data) generation processing, various image processing on the image data, and the like. For example, the image processing circuit 140 converts (scan converts) the scanning mode of B-mode data (morphological information), blood flow information, and elasticity information generated by the signal processing circuit 130 into a display data format. As a result, the image processing circuit 140 calculates B-mode image data (morphological image data) representing the form of the structure of the subject, blood flow image data representing the blood flow movement in the subject, and tissue elasticity in the subject. Each elastic image data to be represented is generated. The image processing circuit 140 stores the generated image data and the image data subjected to various types of 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, and incidental information related to diagnosis such as patient information together with the image data, and stores the image memory 150 may be stored.

  Further, the image processing circuit 140 according to the first embodiment executes an acquisition function 141, an image generation function 142, and a composition function 143. Here, each processing function executed by the acquisition function 141, the image generation function 142, and the composition function 143 that are components of the control circuit 170 is recorded in the storage circuit 160 in the form of a program that can be executed by a computer, for example. Yes. The image processing circuit 140 is a processor that implements a function corresponding to each program by reading each program from the storage circuit 160 and executing the program. That is, the acquisition function 141 is a function that is realized when the image processing circuit 140 reads a program corresponding to the acquisition function 141 from the storage circuit 160 and executes it. The image generation function 142 is a function that is realized when the image processing circuit 140 reads a program corresponding to the image generation function 142 from the storage circuit 160 and executes it. The composition function 143 is a function realized by the image processing circuit 140 reading out a program corresponding to the composition function 143 from the storage circuit 160 and executing it. In other words, the image processing circuit 140 in a state where each program is read out has each function shown in the image processing circuit 140 of FIG. The functions of the acquisition function 141, the image generation function 142, and the composition function 143 will be described later.

  In FIG. 1, it is assumed that 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 are provided. A processing circuit may be configured in combination, and a function may be realized by each processor executing a program.

  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, It means a circuit such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). The processor implements a function by reading and executing a program stored in the storage circuit. Instead of storing the program in the storage circuit 160, the program may be directly incorporated in the processor circuit. In this case, the processor realizes the function by reading and executing the program incorporated in the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining a plurality of independent circuits to realize the function. Good. Furthermore, a plurality of components in FIG. 1 may be integrated into one processor to realize the function.

  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 by an operator after diagnosis, for example, and an ultrasonic image for display via the image processing circuit 140 It becomes data.

  The storage circuit 160 stores a control program for performing ultrasonic transmission / reception, image processing, and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), various data such as a diagnostic protocol and various body marks. . The storage circuit 160 is also used for storing image data stored in the image memory 150 as necessary. The data stored in the storage circuit 160 can be transferred to an external device via an interface unit (not shown).

  The control circuit 170 controls the entire processing of the ultrasonic diagnostic apparatus 1. Specifically, the control circuit 170 is based on various setting requests input from the operator via the input device 102, various control programs and various data read from the storage circuit 160, the transmission circuit 110, the reception circuit 120, Controls processing of the signal processing circuit 130, the image processing circuit 140, and the like. In addition, the control circuit 170 causes the display 103 to display ultrasonic image data stored in the image memory 150.

  The transmission circuit 110, the reception circuit 120, the signal processing circuit 130, the image processing circuit 140, the control circuit 170, and the like built in the apparatus main body 100 are a processor (CPU (Central Processing Unit), MPU (Micro-Processing Unit)). May be configured by hardware such as an integrated circuit or the like, or may be configured by a software modularized program.

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

  However, visibility is not always improved by simply synthesizing. For example, a blood flow image and an elastic image are generally colored and displayed, and thus the visibility may be deteriorated if they are superimposed. Specifically, the blood flow image is colored “red-blue” depending on the direction of blood flow. The elastic image is colored with a gradation that continuously changes from “blue-green-red” depending on the degree (size) of distortion. For this reason, when the blood flow image and the elasticity image are superimposed with a predetermined transparency, it is possible to distinguish, for example, whether the “red” pixel indicates the direction of blood flow or the degree of distortion. On the contrary, the visibility is degraded. Such a decrease in visibility cannot be solved by adjusting the transparency of the two or dividing the imaging region.

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

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

  In addition, 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 thereto. For example, the acquisition function 141 may acquire information other than the above information (for example, incidental information). Further, for example, the acquisition function 141 does not necessarily acquire the above information. For example, when the B mode data is not used in the following processing, the acquisition mode 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 generation function 142 is a B-mode image representing the form of a structure in the subject based on the result of ultrasonic scanning on the subject P, and a blood flow image in which a difference in blood flow information value is represented by a difference in hue. , And an elasticity image in which the difference in elasticity information value is expressed in gray scale. The image generation function 142 is an example of an image generation unit.

  4A and 4B are diagrams for explaining processing of the image generation function 142 according to the first embodiment. FIG. 4A illustrates the elasticity image 10 generated by the image generation function 142. FIG. 4B illustrates the blood flow image 20 generated by the image generation function 142. The broken line in FIG. 4B indicates that the position with the elastic image 10 in FIG. 4A is associated, 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 elastic information scanning method generated by the signal processing circuit 130 into a display data format. The data converted here is data in which the value representing the strain of the tissue at each sample point of the elasticity information is replaced with the pixel value of each pixel of the display image. Then, the image generation function 142 assigns a color corresponding to the pixel value to each pixel in the converted data according to a color look-up table (LUT) for elastic images. Here, in the elastic image color LUT, a gray scale color is set according to the pixel value. That is, the image generation function 142 displays the difference between the pixel values in the elastic image in gray scale. As an example, the image generation function 142 generates the elastic image 10 by assigning a dark gray to a hard part (part having a small distortion) and assigning a light gray to a soft part (a part having a large distortion). .

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

  As shown in FIG. 4B, the image generation function 142 converts the blood flow information scanning method generated by the signal processing circuit 130 into a display data format. The converted data is data in which a value representing blood flow at each sample point of blood flow information is replaced with a pixel value of each pixel of the display image. Then, the image generation function 142 assigns a color corresponding 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, a color including a different hue (color temperature) according to the pixel value is set. That is, the image generation function 142 displays the difference between the pixel values in the blood flow image in hue. As an example, when blood flow power is imaged as blood flow information, the image generation function 142 assigns dark red to a portion with high power and assigns bright red to a portion with low power. Thus, the 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 a hue other than red. In addition, the blood flow image 20 may be expressed in red and blue colors for each direction of blood flow. Furthermore, when displaying the velocity component and the dispersion component of the blood flow, two different color components are displayed. May be used to express a two-dimensional color change. In other words, the blood flow image 20 is expressed by at least a difference in hue among the three elements of color (hue, lightness, and saturation). That is, the difference in the values 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. .

  As described above, the image generation function 142 has the blood flow image 20 in which the difference in blood flow information value is expressed by at least a difference in hue, and the elasticity in which the difference in elastic information value is expressed by a difference other than the hue. An image 10 is generated.

  The composition function 143 generates a composite image by combining the blood flow image 20 and the elastic image 10. For example, the composition function 143 generates a composite image by superimposing the blood flow image 20 on a corresponding position on the elastic image 10. The synthesis function 143 is an example of a synthesis unit.

  FIG. 5 and FIG. 6 are diagrams for explaining processing of the composition function 143 according to the first embodiment. FIG. 5 illustrates a composite image 30 in which the elasticity image 10 in FIG. 4A and the blood flow image 20 in FIG. 4B are combined. FIG. 6 illustrates a display image 40 generated using the composite image 30.

  As shown in FIG. 5, the composition function 143 generates a composite image 30 by superimposing the blood flow image 20 on the elastic image 10. Here, since the elasticity image 10 and the blood flow image 20 are image data generated from the same ultrasonic scanning result, the positions of the sample points (pixels) of both image data correspond to each other. That is, the compositing function 143 superimposes the blood flow image 20 on the corresponding position on the elastic image 10 without aligning the two image data.

  Specifically, the synthesis function 143 extracts a blood flow region from the blood flow image 20. For example, the composition function 143 recognizes a region having Doppler information in the blood flow image 20 (for example, a region having a power value equal to or greater than a threshold value) as a blood flow region, and cuts out an image of the recognized blood flow region. In the example of FIG. 4B, the synthesis function 143 cuts out four shaded areas as blood flow areas. Then, the composition function 143 generates the composite image 30 by superimposing the cut out bloodstream region image on the corresponding position on the elastic image 10. In addition, you may permeate | transmit the image of the blood-flow area | region superimposed here with predetermined | prescribed permeability | transmittance. In the example of FIG. 5, the case where the power image is used as an example of the blood flow image 20 has been described.

  As shown in FIG. 6, the composition function 143 generates a display image 40 to be displayed on the display 103 by combining the composite image 30 and the B mode images 41A and 41B. Specifically, the display image 40 is divided into regions where B-mode images 41A and 41B, which are the same tomographic images, are displayed on the left and right.

  Specifically, the composition function 143 superimposes the composite image 30 in a non-transparent manner at a corresponding position on the B-mode image 41A. This position is determined based on, for example, the position of each sample point in the first ultrasonic scan and the second ultrasonic scan. In this way, by superimposing the composite image 30 on the B-mode image 41A in a non-transparent manner, it is possible to prevent the luminance component of the B-mode image 41A from being mixed in the region of the composite image 30 and reducing the visibility. .

  Further, the compositing function 143 displays the same B mode image 41B as the B mode image 41A in parallel next to the B mode image 41A on which the composite image 30 is superimposed. Also, the composition function 143 displays a frame line 42 corresponding to the range of the composite image 30 on the B-mode image 41B. By displaying the frame line 42, the state of the B-mode image (tomographic image) corresponding to the range of the composite image 30 can be easily browsed, so that the comparative observation of the composite image 30 and the B-mode image 41B becomes easy. .

  As described above, the composition function 143 generates the display image 40. The display image 40 generated by the combining 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 another image is not 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 at a predetermined transmittance at a corresponding position on the B-mode image 41. Further, for example, the composition function 143 may output the composite image 30 itself as the display image 40, or output an image obtained by superimposing the composite image 30 on the B-mode image 41 </ b> A as the display image 40. May be. Further, for example, the composition function 143 may display an image in which the B mode image 41 </ b> B is arranged next to the composite image 30 as the display image 40. That is, the display image 40 includes at least the composite image 30 and can be generated by appropriately combining with other images corresponding to positions.

  For example, FIG. 6 illustrates the case where the two B-mode images 41A and 41B are displayed side by side in the left and right directions. Parallel display is possible in various forms such as display and simultaneous display on different display devices. In addition, three or more images may be displayed in parallel. In the case of parallel display with three images, two images are B-mode images 41A and one image is a B-mode image 41B. Further, 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 flowchart showing a processing procedure of the ultrasonic diagnostic apparatus 1 according to the first embodiment. The processing procedure illustrated in FIG. 7 is started, for example, by receiving an instruction from the operator to start capturing the composite image 30 in a state where the ultrasonic probe 101 is in contact with the body surface of the subject P. .

  In step S101, the ultrasound diagnostic apparatus 1 starts imaging. For example, when receiving an instruction from the operator to start capturing the composite image 30, the control circuit 170 starts capturing the composite image 30. If step S101 is negative, the control circuit 170 does not start shooting and is in a standby state.

  If step S101 is affirmed, the ultrasonic probe 101 performs ultrasonic scanning on the subject P in step S102. For example, the ultrasonic probe 101 performs a first ultrasonic scan and a second ultrasonic 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 ultrasonic scanning to generate B mode data. In addition, the Doppler arithmetic processing circuit 132 applies a clutter removal filter to the reception data sequence collected by the first ultrasonic scanning, and generates blood flow information from the reception data sequence. Further, the strain distribution calculation circuit 133 calculates the displacement by time-integrating the moving speed after the start of the tissue deformation based on the tissue moving speed information acquired from the received data string before applying the clutter removal filter. Further, elasticity information is generated by spatially differentiating the displacement.

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

  In step S105, the composition function 143 generates composite image data. For example, the composition function 143 generates the composite image 30 by superimposing the blood flow image 20 on a corresponding position on the elastic image 10. The combining function 143 combines the display image 40 including the generated combined 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 illustrated in FIG.

  In step S <b> 107, the control circuit 170 determines whether an instruction to end shooting is received from the operator. Here, when Step S107 is denied, control circuit 170 shifts to processing of Step S102. That is, the ultrasonic diagnostic apparatus 1 performs ultrasonic scanning of the next frame, and generates and displays a composite image 30 of the next frame.

  When step S107 is affirmed, the ultrasound diagnostic apparatus 1 ends the process for generating and displaying the composite image 30. FIG. 7 is only an example. For example, the above processing procedures do not necessarily have to be executed in the order described above. For example, the above steps S101 to S107 may be executed by appropriately changing the order as long as the processing contents do not contradict each other.

  As described above, in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the acquisition function 141 acquires blood flow information and tissue property information based on the result of ultrasonic scanning on the subject. The image generation function 142 generates a blood flow image in which a difference in blood flow information value is expressed by at least a difference in hue, and a tissue property image in which a difference in tissue property information value is expressed by a difference other than the hue. To do. The synthesis function 143 generates a synthesized image by synthesizing the blood flow image and the tissue property image. For this reason, the ultrasonic diagnostic apparatus 1 according to the first embodiment can generate a composite image that appropriately represents blood flow and tissue properties.

  For example, the ultrasonic diagnostic apparatus 1 acquires the elastic image 10 and the blood flow image 20 in the same ultrasonic scan, that is, in the same cross section. For this reason, the ultrasonic diagnostic apparatus 1 is expected to improve the accuracy of diagnosis by superimposing both images accurately. Depending on the clinical department and examination type, the elastic image 10 and the blood flow image 20 are often used together, which is 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. Further, the ultrasonic diagnostic apparatus 1 does not need to switch the imaging mode for individually collecting the elastic image 10 and the blood flow image 20, and can reduce the diagnosis time.

  In the ultrasound diagnostic apparatus 1, the image generation function 142 generates a morphological image, a blood flow image, and a tissue property image based on the result of ultrasonic scanning on the subject. Then, the control circuit 170 causes the display 103 to display a display image including the composite image 30 obtained by combining the blood flow image and the tissue property image and a display image including the morphological image 41B. Thereby, the ultrasound diagnostic apparatus 1 can simultaneously browse the morphological image, the blood flow image, and the tissue property image without impairing the visibility.

(Second Embodiment)
In the first embodiment, when the blood flow image 20 and the elastic image 10 are combined, the blood flow image 20 drawn in hue and the elastic image 10 drawn in a single color gradation (for example, gray scale) However, 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 elastic image drawn with hue. Therefore, in the second embodiment, a case will be described in which the ultrasound diagnostic apparatus 1 combines a blood flow image drawn with a single color gradation and an elastic image drawn with a hue.

  The ultrasonic diagnostic apparatus 1 according to the second embodiment has the same configuration as the ultrasonic diagnostic apparatus 1 illustrated in FIG. 1, and part of the processing of the image generation function 142 and the synthesis function 143 is different. Therefore, in the second embodiment, the description will focus on the points that are different from the first embodiment, and the description of the points having the same functions as the configuration described in the first embodiment will be omitted.

  In the image generation function 142 according to the second embodiment, the difference in elasticity information value is expressed by at least a difference in hue, and the difference in blood flow information value is expressed by a difference other than the hue. A blood flow image is generated.

  8A and 8B are diagrams for explaining processing of the image generation function 142 according to the second embodiment. FIG. 8A illustrates an elastic image generated by the image generation function 142. FIG. 8B illustrates a blood flow image generated by the image generation function 142. Note that the broken line in FIG. 8B represents that the position of the elastic image in FIG. 8A is associated, 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 the elastic information generated by the signal processing circuit 130 into a display data format. Then, the image generation function 142 assigns a color corresponding to the pixel value to each pixel in the converted data according to a color look-up table (LUT) for elastic images. Here, in the color LUT for elastic images, colors including different hues (color temperatures) are set according to the pixel values. That is, the image generation function 142 assigns a gradation that continuously changes as “blue-green-red” as the hardness (distortion) changes from a small value (soft) to a large value (hard), An elastic image 50 is generated.

  8B, the image generation function 142 converts the blood flow information scanning method generated by the signal processing circuit 130 into a display data format. Then, the image generation function 142 assigns a gray scale corresponding to the pixel value to each pixel in the converted data in accordance with the blood flow image color LUT. In other words, when the power of blood flow is imaged as blood flow information, the image generation function 142 is a gray scale whose luminance changes as the power changes from a small value (soft) to a large value (hard). Is assigned to generate the blood flow image 60.

  The synthesis function 143 according to the second embodiment generates the synthesized image 70 by superimposing the elastic image 50 on the blood flow image 60.

  FIG. 9 is a diagram for explaining processing of the composition function 143 according to the second embodiment. As illustrated in FIG. 9, for example, the composition function 143 extracts a blood flow region from the blood flow image 60 and fills a region other than the extracted blood flow region with a predetermined luminance (for example, black). Then, the synthesis function 143 superimposes the elasticity image 50 on the blood flow image 60 filled with a region other than the blood flow region with a predetermined transparency (a degree of transparency that allows the lower blood flow image 60 to be viewed). Thus, the composite image 70 is generated. Thereby, the composite image 70 with a clear blood flow region is obtained.

  The synthesis function 143 may generate the composite image 70 by cutting out the blood flow region from the blood flow image 60 and superimposing the cut out blood flow region on the elastic image 50. Here, when assigning a single color gradation to the blood flow image 60, it is preferable not to be close to the hue of the color LUT of the elastic image 50.

  As described above, the ultrasonic diagnostic apparatus 1 according to the second embodiment synthesizes the blood flow image 60 drawn with the single color gradation and the elastic image 50 drawn with the hue, thereby combining the synthesized image 70. Is generated. Thereby, the ultrasonic diagnostic apparatus 1 according to the second embodiment can generate a composite image that appropriately represents blood flow and tissue properties.

(Third embodiment)
In the first and second embodiments described above, the case where the elastic image is generated using the TDI method has been described, but the embodiment is not limited thereto. For example, the ultrasonic diagnostic apparatus 1 may generate an elastic image based on a correlation calculation between adjacent frames. Therefore, in the third embodiment, a case will be described in which the ultrasound diagnostic apparatus 1 generates an elastic image based on a correlation calculation 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. 1, and a part of the processing of the signal processing circuit 130 is different. Therefore, in the third embodiment, description will be made mainly on points different from the first embodiment, and description of points having the same functions as those of the configuration described in the first embodiment will be omitted.

  FIG. 10 is a block diagram illustrating 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 distortion distribution calculation circuit 133, a Doppler calculation processing circuit 134, and a cross-correlation calculation circuit 135. The B mode processing circuit 131 and the distortion distribution calculation circuit 133 are the same as the B mode processing circuit 131 and the distortion distribution calculation circuit 133 shown in FIG.

  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 generation circuit 132B, and is different in that it does not include a tissue movement speed generation 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. That is, the Doppler arithmetic processing circuit 134 generates blood flow information by substantially the same processing as the Doppler arithmetic processing circuit 132.

  The 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 calculation circuit 133 that generates elasticity information.

  FIG. 11 is a diagram for explaining the processing of the cross-correlation arithmetic circuit 135 according to the third embodiment. FIG. 11 illustrates a scan sequence similar to that in 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 IQ signals (or RF signals) at the same position between adjacent frames, thereby expressing the tissue displacement between the frames. Generate displacement information. Specifically, as shown by the arrows in FIG. 11, the cross-correlation calculation circuit 135 acquires IQ signals from the first ultrasonic scans executed in the nth frame and the n + 1th frame, respectively. The cross-correlation calculation circuit 135 calculates the tissue correlation information between these frames by calculating the cross-correlation of IQ signals at the same position between the nth frame and the (n + 1) th frame. Then, the strain distribution calculation circuit 133 calculates elasticity information by spatially differentiating the tissue displacement generated by the cross correlation calculation circuit 135.

  As described above, the Doppler calculation processing circuit 134 can generate elasticity information (tissue property information) based on the correlation calculation between received data between adjacent frames. The elasticity information (elastic 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 frame or the (n + 1) th frame. As a result, it is possible to simultaneously display information of substantially the same time and substantially the same cross section.

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

  For example, in the configuration described in the first to third embodiments, in order to improve the performance of the MTI filter 132A, the data string (packet) of reflected wave data obtained by ultrasonic scanning of each frame is increased. 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.

  Regarding the collection 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 form that can collect reflected wave data at the same position over a plurality of frames. Run repeatedly. In addition, regarding the acquisition of tomographic information, the control circuit 170 executes partial ultrasonic scanning in which the scanning range is divided over a plurality of frames while switching the divided range. That is, the control circuit 170 executes partial ultrasonic scanning in which the scanning range is divided between the ultrasonic scanning of blood flow information repeatedly executed over a plurality of frames while switching the divided range.

  FIG. 12 is a diagram for explaining processing of the control circuit 170 according to the fourth embodiment. “B” shown in FIG. 12 indicates a range where ultrasonic scanning is performed using the transmission / reception conditions for the B mode. That is, the range in which the B-mode ultrasonic scanning is performed is divided into four divided ranges (first divided range to fourth divided range). In addition, “D” illustrated in FIG. 12 indicates a range in which ultrasonic scanning is performed using transmission / reception conditions for the color Doppler mode. For example, “D” shown in FIG. 12 is a range in which ultrasonic scanning performed by the high frame rate method is performed. That is, the ultrasonic scanning illustrated in FIG. 12 does not transmit the ultrasonic wave a plurality of times in the same direction and receive the reflected wave a plurality of times, as in a general color Doppler method, Sound wave transmission / reception is performed once. The control circuit 170 performs ultrasonic transmission / reception once for each of a plurality of scanning lines forming a scanning range as an ultrasonic scanning for the color Doppler mode, and acquires blood flow information using reflected waves for a plurality of frames. An ultrasonic scan based on the method (high frame rate method) is executed.

  First, the control circuit 170 performs B-mode ultrasonic scanning for the first divided range (see (1) in FIG. 12), and superimposes for color Doppler mode for the scanning range for one frame. Sound wave scanning is executed (see (2) in FIG. 12). Then, the control circuit 170 executes B-mode ultrasonic scanning for the first divided range (see (3) in FIG. 12), and superimposes for color Doppler mode for the scanning range for one frame. Sound wave scanning is executed (see (4) in FIG. 12). Then, the control circuit 170 executes B-mode ultrasonic scanning for the first divided range (see (5) in FIG. 12), and superimposes for color Doppler mode for the scanning range for one frame. Sound wave scanning is executed (see (6) in FIG. 12). Then, the control circuit 170 executes B-mode ultrasonic scanning for the first divided range (see (7) in FIG. 12), and superimposes for color Doppler mode for the scanning range for one frame. Sound wave scanning is executed (see (8) in FIG. 12).

Here, as illustrated in FIG. 12, the control circuit 170 sets the intervals at which the ultrasonic scanning for the color Doppler mode is performed at equal intervals. That is, the “point X” on the scanning range is scanned once by the ultrasonic scanning of (2), (4), (6) and (8) in FIG. 12, but the scanning interval is constant. It is controlled to be “T”. Specifically, the control circuit 170 sets the time required for each divided scan performed in the B-mode ultrasonic scan to be the same, and sets the intervals at which the color Doppler mode ultrasonic scan is performed to be equal intervals. For example, the control circuit 170 ensures that the time required for the divided scanning of the B-mode ultrasonic scanning performed in (1), (3), (5), and (7) in FIG. Control. The control circuit 170 makes the size of each division range, the number of scanning lines, the scanning line density, the depth, and the like the same. For example, if the number of scanning lines is the same, the time required for each divided scan of the ultrasonic scanning for the B mode is the same. The signal processing circuit 130 applies to a data string (“X _n−3 , X _n−2 , X _n−1 , X _n ,...” Shown in FIG. 12) at the same position between “D” frames. Then, processing such as correlation calculation is 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 the frame period for forming one tomographic image, and performs imaging and display of the blood flow information and elasticity information, so that the ultrasound diagnosis apparatus 1 performs substantially the same time and almost the same time. It is possible to simultaneously display information on the same cross section.

(Other embodiments)
In addition to the above-described embodiment, various other forms may be implemented.

(When morphological image, blood flow image, and elasticity image are generated by different ultrasound scans)
In the above-described embodiment, for example, the case where the blood flow image and the elasticity image are generated by the same ultrasonic scanning has been described, but the embodiment is not limited thereto. For example, the morphological image, the blood flow image, and the elasticity image may be generated by different ultrasonic scans.

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

  Here, the third ultrasonic scanning is executed to generate an elasticity image (elasticity information). In this case, for example, the signal processing circuit 130 generates tissue movement speed information from the reflected wave data obtained by the third ultrasonic scanning by the TDI method, and calculates elasticity information. The signal processing circuit 130 may generate an elastic image based on a correlation calculation between adjacent frames.

(Application of share wave elastography)
Further, in the above-described embodiment, a case is described in which an elastic image is generated by strain elastography that images strain (strain) generated by weak vibration generated by the action of bringing the ultrasonic probe 101 into contact with the body surface. However, the embodiment is not limited to this. For example, by applying acoustic radiation force (push pulse) from the body surface to living tissue to generate displacement based on shear wave, and observing the displacement at each point in the scanning section over time, shear wave Shear wave elastography for obtaining the elastic modulus from the propagation speed of may be applied.

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

  Here, the third ultrasonic scanning is an ultrasonic scanning for generating an elastic image (elastic information) by shear wave elastography. However, in shear wave elastography, shear waves generated by one push pulse transmission are attenuated along with propagation, so that one region of interest is scanned by dividing it into a plurality of small regions. FIG. 13 illustrates a case where the region of interest is scanned in three small regions, and one elastic image corresponding to the region of interest is obtained by combining the elastic images of the three small regions. Here, for convenience of explanation, the three small regions are denoted as small regions A, B, and C.

  That is, in the nth frame, a blood flow image is generated from the first ultrasonic scan, a morphological image is generated from the second ultrasonic scan, and an elastic image of the small region A is generated from the third ultrasonic scan. The Subsequently, in the (n + 1) 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 elastic image of the small region B is generated from the third ultrasonic scan. Is done. In the (n + 2) 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 elastic image of the small region C is generated from the third ultrasonic scan. The Here, by combining the elastic images of the small regions A, B, and C, it is possible to generate one elastic image corresponding to the region of interest. In other words, the elastic image generated by the shear wave elastography has a lower frame rate according to the number of small regions than the blood flow image and the morphological image. The elastic image generated by share wave elastography is the same as the elastic image generated by the strain elastography described in the above embodiment except that the frame rate is low. Available for display.

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

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

  In addition, the ASQ mode image is an image obtained by obtaining the degree of deviation (dispersion value) from the Rayleigh distribution of the signal amplitude distribution of the received signal by statistical filtering and imaging the dispersion value.

  The micro calcification-enhanced image is an image obtained by extracting fine calcification generated in the tissue to be observed from the B-mode image and imaging the extracted fine calcification.

  When the above attenuated image, ASQ mode image, and microcalcification-enhanced image are combined with a blood flow image as a tissue property image, the blood flow image is represented by a difference in hue, and the tissue property image is represented by a difference other than the hue. It is preferred to be expressed.

(Medical image processing device)
Further, the processing described in the above-described embodiment may be executed in a medical image processing apparatus.

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

  The input device 201 includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, and the like, receives various setting requests from an operator of the medical image processing apparatus 200, and receives various settings received. The request is transferred to each processing unit.

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

  The storage circuit 210 is a non-volatile storage device such as a semiconductor memory element such as a flash memory or 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 entire processing of the medical image processing apparatus 200.

  In addition, the processing circuit 220 executes 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 composition function 223 include functions similar to the acquisition function 141, the image generation function 142, and the composition function 143 described in the above embodiment.

  That is, the acquisition function 221 acquires blood flow information and tissue property information. From the blood flow information acquired by the acquisition function 221, the image generation function 222 is a blood in which a difference in blood flow information including a value based on blood flow at each position in the subject is expressed by at least a difference in hue. A flow image 20 is generated. Further, the image generation function 222 expresses the difference in the value of the tissue property information including the value based on the tissue property at each position in the subject from the tissue property information acquired by the acquisition function 221 with a difference other than the hue. The elastic 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 composition function 223 generates a composite image 30 by combining the blood flow image 20 and the elasticity image 10.

  The medical image processing apparatus 200 may acquire the generated blood flow image 20 and the 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 the modalities, respectively, and stores the acquired blood flow image 20 and the elasticity image 10 in the storage circuit 210. Then, the composition function 223 generates a composite image 30 by combining the blood flow image 20 and the elasticity image 10.

  In FIG. 14, the case where the composite image 30 is generated by combining the blood flow image 20 and the elastic image 10 has been described. However, the composite image 70 is generated by combining the blood flow image 60 and the elastic image 50. May be.

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

  In addition, among the processes described in the above embodiment, all or a part of the processes described as being automatically performed can be manually performed, or the processes described as being manually performed All or a part of the above can be automatically performed by a known method. In addition, the processing procedure, control procedure, specific name, and information including various data and parameters shown in the above-described document and drawings can be arbitrarily changed unless otherwise specified.

  In addition, the medical image processing method described in the above embodiment can be realized by executing a medical image processing program prepared in advance 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. The medical image processing program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, and a DVD, and can be executed by being read from the recording medium by the computer. it can.

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

  Although several embodiments of the present invention have been described, these embodiments are 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 changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 140 Image processing circuit 141 Acquisition function 142 Image generation function 143 Composition function

Claims (12)

Based on the result of the first ultrasonic scan for the subject, blood flow information including a value representing the blood flow at each position in the first region in the subject is acquired, and the second ultrasonic scan for the subject is acquired. Based on the result, an acquisition unit that acquires tissue property information including a value representing the tissue property in each position in the second region overlapping the first region;
A combining unit that generates a combined image by combining the first image based on the blood flow information and the second image based on the tissue property information;
With
The second ultrasonic scan includes generating a shear wave by applying an acoustic radiation force to the subject and observing a displacement due to the shear wave over time at each position in the second region. Ultrasound diagnostic device.   The ultrasonic diagnostic apparatus according to claim 1, wherein the acquisition unit acquires the tissue property information by analyzing a result of the second ultrasonic scan by a Doppler method. The blood flow information includes a power value as a value representing the blood flow,
The ultrasonic diagnostic apparatus according to claim 1, wherein the first image is a power image based on the power value. The first ultrasonic scan includes repeating the ultrasonic scan for the first region a plurality of times;
The acquisition unit acquires, for each position in the first region, a data string composed of reception data collected in each of the plurality of ultrasonic scans, and acquires the blood flow information based on the data string, The ultrasonic diagnostic apparatus as described in any one of Claims 1 thru | or 3. The acquisition unit acquires morphological information at each position in a third region that overlaps the first region and the second region, based on a result of a third ultrasonic scan on the subject,
The synthesizing unit generates the synthesized image by synthesizing the first image, the second image, and a third image based on the form information;
The ultrasound according to any one of claims 1 to 4, wherein the first ultrasound scan, the second ultrasound scan, and the third ultrasound scan are executed in a time-sharing manner as a series of scan sequences. Ultrasonic diagnostic equipment.   6. The ultrasonic diagnostic apparatus according to claim 5, wherein in the series of scan sequences, a time during which the first ultrasonic scan is executed is longer than a time during which the second ultrasonic scan is executed.   The ultrasonic diagnostic apparatus according to claim 5, wherein the series of scan sequences is repeated a plurality of times. Based on the result of the first ultrasonic scan for the subject, blood flow information including a value representing the blood flow at each position in the first region in the subject is acquired, and the second ultrasonic scan for the subject is acquired. On the basis of the result of the acquisition of tissue property information including a value representing the tissue property in each position in the second region overlapping the first region, based on the result of the third ultrasonic scan on the subject, An acquisition unit that acquires morphological information at each position in the third region overlapping the first region and the second region;
A combining unit that generates a combined image by combining the first image based on the blood flow information, the second image based on the tissue property information, and the third image based on the morphological information;
With
The first ultrasonic scan, the second ultrasonic scan, and the third ultrasonic scan are executed in a time-sharing manner as a series of scan sequences,
In the series of scan sequences, an ultrasonic diagnostic apparatus in which a time during which the first ultrasonic scan is executed is longer than a time during which the second ultrasonic scan is executed. The first ultrasonic scan includes repeating the ultrasonic scan for the first region a plurality of times;
The acquisition unit acquires, for each position in the first region, a data string composed of reception data collected in each of the plurality of ultrasonic scans, and acquires the blood flow information based on the data string, The ultrasonic diagnostic apparatus according to claim 8.   The ultrasonic diagnostic apparatus according to claim 8 or 9, wherein the series of scan sequences is repeated a plurality of times. Based on the result of the first ultrasonic scan for the subject, blood flow information including a value representing the blood flow at each position in the first region in the subject is acquired, and the second ultrasonic scan for the subject is acquired. Based on the result, an acquisition unit that acquires tissue property information including a value representing the tissue property in each position in the second region overlapping the first region;
A combining unit that generates a combined image by combining the first image based on the blood flow information and the second image based on the tissue property information;
With
The first ultrasonic scan includes repeating the ultrasonic scan for the first region a plurality of times;
The acquisition unit acquires, for each position in the first region, a data string composed of reception data collected in each of the plurality of ultrasonic scans, and acquires the blood flow information based on the data string, Ultrasonic diagnostic equipment. The blood flow information includes a power value as a value representing the blood flow,
The ultrasonic diagnostic apparatus according to claim 11, wherein the first image is a power image based on the power value.