阅读说明：本技术 超声诊断装置及其操作方法 (Ultrasonic diagnostic apparatus and method of operating the same ) 是由 孔栋建 李烔机 金洨槿 于 2018-03-28 设计创作，主要内容包括：根据一个公开的实施例,提供了一种用于处理剪切波弹性成像数据的方法,所述方法包括以下步骤：在对象的感兴趣区域处发射聚焦超声波束以便在对象的感兴趣区域中引起剪切波；获取引起剪切波的对象的超声图像；通过使用超声图像分别在多个测量点中的每个测量点处测量剪切波到达时间,其中,所述多个测量点中的每个测量点与发射聚焦超声波束的焦点间隔开预设距离；基于测量的剪切波到达时间检测感兴趣区域中的混响；以及显示混响检测信息。(According to disclosed embodiments, there are provided methods for processing shear wave elastography data, the method including the steps of emitting a focused ultrasound beam at a region of interest of a subject so as to induce a shear wave in the region of interest of the subject, acquiring an ultrasound image of the subject inducing the shear wave, measuring a shear wave arrival time at each of a plurality of measurement points by using the ultrasound image, respectively, wherein each of the plurality of measurement points is spaced apart from a focal point at which the focused ultrasound beam is emitted by a preset distance, detecting reverberation in the region of interest based on the measured shear wave arrival time, and displaying reverberation detection information.)

1, a method of processing shear wave elastography data relating to a subject using an ultrasound diagnostic apparatus, the method comprising:

inducing shear waves in a region of interest of a subject by emitting a focused ultrasound beam onto the region of interest of the subject;

acquiring ultrasound images of an object causing shear waves at a plurality of time points, respectively;

measuring shear wave arrival times at a plurality of measurement points, respectively, by using the ultrasound image, wherein the plurality of measurement points are spaced apart from a focal point on which the focused ultrasound beam is focused by a preset distance;

detecting reverberation in the region of interest based on the measured shear wave arrival times; and

displaying information about the detected reverberation.

2. The method according to claim 1, further comprising, before transmitting the focused ultrasound beam, transmitting th ultrasound signals to the subject and generating a reference ultrasound image by using ultrasound echo signals reflected from the subject,

wherein the step of obtaining an ultrasound image comprises: transmitting a second ultrasonic signal to the object causing the shear wave and obtaining a plurality of shear wave images at the plurality of time points, respectively, by using ultrasonic echo signals reflected from the object.

3. The method of claim 1, wherein the step of measuring shear wave arrival times comprises:

calculating a plurality of time points when the displacement of the tissue of the object respectively located at the plurality of measurement points respectively reaches a maximum value by comparing each of the plurality of shear wave images with a reference ultrasound image; and

determining the calculated plurality of time points as shear wave arrival times at the plurality of measurement time points, respectively.

4. The method of claim 1, wherein the step of detecting reverberation comprises:

determining th average shear wave arrival time as an average of the shear wave arrival times corresponding respectively to the plurality of measurement points;

determining an average of differences as second average shear wave arrival times, each of the differences being a difference between shear wave arrival times at two adjacent ones of the plurality of measurement points; and

the occurrence of reverberation is detected by comparing a preset threshold with a value obtained by dividing the th average shear wave arrival time by the second average shear wave arrival time.

5. The method of claim 1, wherein the step of detecting reverberation comprises:

calculating a shear wave velocity by dividing the average of the distances of the plurality of measurement points by the average of the shear wave arrival times measured at the plurality of measurement points, respectively;

calculating a second shear wave velocity by dividing the distance between two adjacent measurement points of the plurality of measurement points by the difference between the shear wave arrival times measured at the two adjacent measurement points, respectively; and

the occurrence of reverberation is detected based on the th shear wave velocity and the second shear wave velocity.

an ultrasonic diagnostic apparatus for processing shear wave elastography data about a subject, the ultrasonic diagnostic apparatus comprising:

an ultrasound probe configured to: inducing shear waves in a region of interest of a subject by emitting a focused ultrasound beam onto the region of interest of the subject;

a processor configured to: obtaining ultrasound images of a subject at a plurality of time points, respectively, measuring shear wave arrival times at a plurality of measurement points, respectively, spaced apart from a focus at which a focused ultrasound beam is focused by a preset distance, and detecting reverberation in a region of interest based on the measured shear wave arrival times; and

a display that displays information about the detected reverberation.

7. The ultrasonic diagnostic apparatus according to claim 6, wherein the ultrasonic probe is further configured to emit th ultrasonic signals to the subject before emitting the focused ultrasonic beam, and the processor is further configured to generate a reference ultrasonic image by using ultrasonic echo signals reflected from the subject, and

wherein the ultrasound image is a plurality of shear wave images obtained by the processor at the plurality of time points, respectively.

8. The ultrasonic diagnostic device according to claim 7, wherein the processor is further configured to: calculating a plurality of time points when the displacement of the tissue of the subject respectively located at the plurality of measurement points respectively reaches a maximum value by comparing each of the plurality of shear wave images with a reference ultrasound image, and determining the calculated plurality of time points as shear wave arrival times at the plurality of measurement time points.

9. The ultrasonic diagnostic apparatus according to claim 6, wherein the processor is further configured to determine an average of shear wave arrival times respectively corresponding to the plurality of measurement points as an th average shear wave arrival time, determine an average of differences as a second average shear wave arrival time, wherein each of the differences is a difference between shear wave arrival times at two adjacent measurement points of the plurality of measurement points, and detect occurrence of reverberation by comparing a preset threshold with a value obtained by dividing a th average shear wave arrival time by the second average shear wave arrival time.

10. The ultrasonic diagnostic device according to claim 9, wherein the processor is further configured to detect the occurrence of reverberation by comparing the th average shear wave arrival time with a preset reference time.

11. The ultrasonic diagnostic apparatus according to claim 6, wherein the processor is further configured to calculate an th shear-wave velocity by dividing an average of distances of the plurality of measurement points by an average of shear-wave arrival times measured at the plurality of measurement points, respectively, calculate a second shear-wave velocity by dividing a distance between two adjacent measurement points of the plurality of measurement points by a difference between shear-wave arrival times measured at the two adjacent measurement points, respectively, and detect occurrence of reverberation based on the th shear-wave velocity and the second shear-wave velocity.

12. The ultrasonic diagnostic apparatus according to claim 11, wherein the processor is further configured to detect occurrence of reverberation by comparing a value obtained by dividing a difference between the second shear-wave velocity and the -th shear-wave velocity by the -th shear-wave velocity with a preset threshold.

13. The ultrasonic diagnostic apparatus according to claim 12, wherein the processor is further configured to determine a value obtained by dividing a difference between the second shear-wave velocity and the th shear-wave velocity by the th shear-wave velocity as a Reliability Measurement Indicator (RMI), and

wherein the display further displays a reliability measurement indicator.

14. The ultrasonic diagnostic apparatus according to claim 6, wherein the display further displays information on the detected reverberation via a user interface including at least items of phrases, sentences, symbols, and colors.

15, a computer program product comprising a computer-readable storage medium including instructions for performing the method of any of claims 1-5, the method comprising:

inducing shear waves in a region of interest of a subject by emitting a focused ultrasound beam onto the region of interest of the subject;

acquiring ultrasound images of an object causing shear waves at a plurality of time points, respectively;

measuring shear wave arrival times at a plurality of measurement points, respectively, spaced apart from a focal point on which a focused ultrasonic beam is focused by a preset distance, by using an ultrasonic image;

detecting reverberation in the region of interest based on the measured shear wave arrival times; and

displaying information about the detected reverberation.

Technical Field

The present disclosure relates to ultrasonic diagnostic apparatuses, methods of controlling ultrasonic diagnostic apparatuses, and computer program products in which program instructions for executing the methods of controlling ultrasonic diagnostic apparatuses are stored.

Background

Recently, in the medical field, various types of medical imaging apparatuses have been widely used for visualizing and acquiring information on living tissues of a human body for early diagnosis or surgery for various diseases.

An ultrasonic diagnostic apparatus transmits ultrasonic signals generated by a transducer of a probe to a subject and receives information of echo signals reflected from the subject, thereby acquiring an image of the inside of the subject, in particular, the ultrasonic diagnostic apparatus is used for medical purposes including observing an internal region of the subject, detecting foreign objects, and evaluating injuries.

Further, the ultrasonic diagnostic apparatus may provide a luminance (B) mode image representing the reflection coefficient of an ultrasonic signal reflected from an object as a two-dimensional (2D) image, a doppler (D) mode image displaying an image of a moving object (particularly, blood flow) by using the doppler effect, an elastic mode image visualizing a difference between a response when a squeeze is applied to the object and a response when no squeeze is applied to the object, and the like.

Disclosure of Invention

Means for solving the problems

an apparatus and method for generating ultrasound elastography images by using shear waves and detecting the occurrence of reverberation in the ultrasound elastography images are provided.

an apparatus and method for displaying information about detected reverberation to inform of the occurrence of reverberation are also provided.

Advantageous effects of the disclosure

According to an embodiment of the present disclosure, occurrence of reverberation may be detected and information about the detected reverberation is displayed and notified to a user, thereby improving accuracy of elasticity measurement.

Further, when reverberation occurs, the user may be allowed to manipulate the probe so that severe reverberation does not occur, or a region of interest (ROI) may be moved to a region of mild reverberation, thereby facilitating elasticity measurement and improving user convenience.

Drawings

The present disclosure will now be described more fully hereinafter with reference to the accompanying detailed description, in which reference numerals refer to structural elements.

Fig. 1 is a block diagram of a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Fig. 2a to 2c show an ultrasonic diagnostic apparatus according to an embodiment.

Fig. 3 is a block diagram illustrating components of an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Fig. 4 is a flowchart of a method of detecting occurrence of reverberation in a region of interest (ROI) and displaying information on the reverberation performed by an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Fig. 5 is a diagram for explaining a method of causing a displacement in tissue of an ROI and calculating the displacement, which is performed by an ultrasonic diagnostic apparatus, according to an embodiment of the present disclosure.

Fig. 6 is a flowchart of a method of measuring shear wave arrival time by tissue displacement in a ROI performed by an ultrasonic diagnostic device according to an embodiment of the present disclosure.

Fig. 7a is a graphical representation of the coordinates of the positions of a plurality of scan lines in an ROI and the direction of focus of a focused ultrasound beam applied to the ROI in the depth direction.

Fig. 7b is a diagram for explaining a method of calculating a shear wave propagation velocity at a plurality of measurement points within an ROI, performed by an ultrasonic diagnostic apparatus, according to an embodiment of the present disclosure.

Fig. 7c is a graph showing the relationship between shear wave arrival time and tissue displacement measured by the ultrasonic diagnostic apparatus at each of a plurality of measurement points according to an embodiment of the present disclosure.

Fig. 8 is a flowchart of a method performed by an ultrasound diagnostic apparatus to detect the occurrence of reverberation based on shear wave arrival times at a plurality of measurement points within an ROI according to an embodiment of the present disclosure.

Fig. 9 is a graph showing shear wave arrival times measured at a plurality of measurement points, respectively, by an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Fig. 10 is a flowchart of a method performed by an ultrasound diagnostic apparatus to detect the occurrence of reverberation based on shear wave velocities calculated at a plurality of measurement points within an ROI according to an embodiment of the present disclosure.

Fig. 11a and 11b are graphs for explaining a method of determining a value of a reliability measurement index based on a shear wave velocity ratio performed by an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Fig. 12a and 12b are diagrams for explaining a method of displaying information on detected reverberation performed by an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure.

Detailed Description

Best mode for carrying out the invention

According to aspects of the present disclosure, methods of processing shear wave elastography data about a subject by using an ultrasound diagnostic apparatus include inducing shear waves in a region of interest of the subject by emitting a focused ultrasound beam onto the region of interest of the subject, obtaining ultrasound images of the subject inducing shear waves at a plurality of time points, respectively, measuring shear wave arrival times at a plurality of measurement points, respectively, by using the ultrasound images, wherein the plurality of measurement points are spaced apart from a focus at which the focused ultrasound beam is focused by a preset distance, detecting reverberation in the region of interest based on the measured shear wave arrival times, and displaying information about the detected reverberation.

The method may further include transmitting th ultrasonic signals to the subject and generating a reference ultrasonic image by using the ultrasonic echo signals reflected from the subject before transmitting the focused ultrasonic beam, and the step of obtaining the ultrasonic images may include transmitting second ultrasonic signals to the subject causing the shear waves and obtaining a plurality of shear wave images at the plurality of time points, respectively, by using the ultrasonic echo signals reflected from the subject.

The step of measuring the shear wave arrival time may comprise: calculating a plurality of time points when the displacement of the tissue of the object respectively located at the plurality of measurement points respectively reaches a maximum value by comparing each of the plurality of shear wave images with a reference ultrasound image; and determining the calculated plurality of time points as shear wave arrival times at the plurality of measurement time points, respectively.

The step of detecting reverberation may include determining an average of shear wave arrival times respectively corresponding to the plurality of measurement points as an th average shear wave arrival time, determining an average of differences as a second average shear wave arrival time, each of the differences being a difference between shear wave arrival times at two adjacent measurement points of the plurality of measurement points, and detecting occurrence of reverberation by comparing a preset threshold with a value obtained by dividing the th average shear wave arrival time by the second average shear wave arrival time.

The step of detecting reverberation may further include detecting the occurrence of reverberation by comparing the th average shear wave arrival time with a preset reference time.

The step of detecting reverberation may include calculating a shear wave speed by dividing an average of distances of the plurality of measurement points by an average of shear wave arrival times measured at the plurality of measurement points, respectively, calculating a second shear wave speed by dividing a distance between two adjacent measurement points of the plurality of measurement points by a difference between shear wave arrival times measured at the two adjacent measurement points, respectively, and detecting an occurrence of reverberation based on the shear wave speed and the second shear wave speed.

The step of detecting reverberation may further include detecting occurrence of reverberation by comparing a value obtained by dividing a difference between the second shear-wave velocity and the th shear-wave velocity by the th shear-wave velocity with a preset threshold.

The step of detecting reverberation may further include determining a value obtained by dividing a difference between the second shear-wave velocity and the th shear-wave velocity by the th shear-wave velocity as a Reliability Measurement Indicator (RMI), and the step of displaying information on the detected reverberation includes displaying the RMI on a display of the ultrasonic diagnostic apparatus.

The step of displaying information about the detected reverberation may comprise displaying information about the detected reverberation via a user interface comprising at least items of a phrase, sentence, symbol and color.

The step of displaying information on the detected reverberation may further include outputting the information on the detected reverberation in the form of a sound including at least of a buzzer, a melody, and a voice.

According to another aspect of the present disclosure, a ultrasonic diagnostic apparatus for processing shear wave elastography data about a subject includes an ultrasonic probe configured to induce shear waves in a region of interest of the subject by emitting a focused ultrasonic beam onto the region of interest of the subject, a processor configured to obtain ultrasonic images of the subject at a plurality of time points, respectively, measure shear wave arrival times at a plurality of measurement points, respectively, and detect reverberation in the region of interest based on the measured shear wave arrival times, wherein the plurality of measurement points are spaced apart from a focal point at which the focused ultrasonic beam is focused by a preset distance, and a display displaying information about the detected reverberation.

The ultrasound probe may transmit th ultrasound signals to the subject before transmitting the focused ultrasound beams, and the processor may generate a reference ultrasound image by using ultrasound echo signals reflected from the subject, wherein the ultrasound images are a plurality of shear wave images obtained by the processor at the plurality of time points, respectively.

The processor may calculate a plurality of time points when the displacement of the tissue of the object respectively located at the plurality of measurement points respectively reaches a maximum value by comparing each of the plurality of shear wave images with the reference ultrasound image, and determine the calculated plurality of time points as shear wave arrival times at the plurality of measurement time points.

The processor may determine an average of shear wave arrival times respectively corresponding to the plurality of measurement points as an th average shear wave arrival time, determine an average of differences as a second average shear wave arrival time, and detect occurrence of reverberation by comparing a preset threshold with a value obtained by dividing a th average shear wave arrival time by the second average shear wave arrival time, wherein each of the differences is a difference between shear wave arrival times at two adjacent measurement points of the plurality of measurement points.

The processor may detect the occurrence of reverberation by comparing the th average shear wave arrival time to a preset reference time.

The processor may calculate an th shear-wave velocity by dividing an average of distances of the plurality of measurement points by an average of shear-wave arrival times measured at the plurality of measurement points, respectively, calculate a second shear-wave velocity by dividing a distance between two adjacent measurement points of the plurality of measurement points by a difference between shear-wave arrival times measured at the two adjacent measurement points, respectively, and detect an occurrence of reverberation based on the th shear-wave velocity and the second shear-wave velocity.

The processor may detect the occurrence of reverberation by comparing a value obtained by dividing a difference between the second shear-wave velocity and the th shear-wave velocity by the th shear-wave velocity with a preset threshold.

The processor may determine a value obtained by dividing a difference between the second shear-wave velocity and the th shear-wave velocity by the th shear-wave velocity as RMI, and the display may display RMI.

The display may display information about the detected reverberation via a user interface including at least terms of phrases, sentences, symbols, and colors.

According to another aspect of the disclosure, the computer program products include a computer readable storage medium for performing a method of processing shear wave elastography data.

Embodiments of the present disclosure

This description describes the principles of the present disclosure and sets forth embodiments thereof to clarify the scope of the present disclosure and to enable one of ordinary skill in the art to practice the embodiments of the present disclosure. Embodiments of the present disclosure may take different forms.

The terms "module" or "unit" used herein may be implemented as software, hardware, firmware, or any combination of two or more thereof, and a plurality of "modules" or "units" may be formed as a single element or "modules" or "units" may include a plurality of elements according to an embodiment.

Hereinafter, the operational principles and embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In an exemplary embodiment, the image may include any medical image obtained by various medical imaging devices, such as a Magnetic Resonance Imaging (MRI) device, a Computed Tomography (CT) device, an ultrasound imaging device, or an X-ray device.

Further, in this specification, an "object" as the thing to be imaged may include parts of a human, animal or human or animal, for example, an object may include parts of a human (i.e., an organ or tissue) or a phantom.

Throughout the specification, an ultrasound image refers to an image of an object processed based on an ultrasound signal transmitted to and reflected from the object.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, the ultrasonic diagnostic apparatus 100 may include a probe 20, an ultrasonic transceiver 110, a controller 120, an image processor 130, or more displays 140, a storage 150 (e.g., memory), a communicator 160 (i.e., a communication device or interface), and an input interface 170.

The ultrasonic diagnostic apparatus 100 may be a cart-type ultrasonic diagnostic apparatus or a portable ultrasonic diagnostic apparatus. Examples of the portable ultrasonic diagnostic apparatus may include a smart phone, a laptop computer, a Personal Digital Assistant (PDA), and a tablet Personal Computer (PC), each of which may include a probe and a software application, but the embodiment is not limited thereto.

The probe 20 may include a plurality of transducers that may transmit ultrasonic signals to the subject 10 in response to transmit signals received by the probe 20 from the transmitter 113. the plurality of transducers may receive ultrasonic signals reflected from the subject 10 to produce receive signals. additionally, the probe 20 and the ultrasonic diagnostic apparatus 100 may be formed in bodies (e.g., disposed in a single housing), or the probe 20 and the ultrasonic diagnostic apparatus 100 may be formed separately (e.g., disposed in separate housings, respectively) but connected wirelessly or via a cable.

The controller 120 may control the transmitter 113 to cause the transmitter 113 to generate a transmit signal to be applied to each of the plurality of transducers based on the position and focus of the plurality of transducers included in the probe 20.

The controller 120 may control the ultrasound receiver 115 to generate ultrasound data based on the positions and focal points of the plurality of transducers by: the reception signals received from the probes 20 are converted from analog signals to digital signals, and the reception signals converted into digital form are added.

The image processor 130 may generate an ultrasound image by using the ultrasound data generated from the ultrasound receiver 115.

The display 140 may display the generated ultrasound image and various information processed by the ultrasound diagnostic apparatus 100. According to the present exemplary embodiment, the ultrasonic diagnostic apparatus 100 may include two or more displays 140. The display 140 may include a touch screen in combination with a touch panel.

The controller 120 may control the operation of the ultrasonic diagnostic apparatus 100 and the signal flow between internal elements of the ultrasonic diagnostic apparatus 100. The controller 120 may include: a memory for storing a program or data for performing the functions of the ultrasonic diagnostic apparatus 100; and a processor and/or microprocessor (not shown) for processing the program or data. For example, the controller 120 may control the operation of the ultrasonic diagnostic apparatus 100 by receiving a control signal from the input interface 170 or an external device.

The ultrasonic diagnostic apparatus 100 may include a communicator 160, and may be connected to external apparatuses such as a server, medical apparatuses, and portable devices (such as a smart phone, a tablet Personal Computer (PC), a wearable device, etc.) via the communicator 160.

The communicator 160 may include at least elements capable of communicating with external devices, for example, the communicator 160 may include at least of a short-range communication module, a wired communication module, and a wireless communication module.

The communicator 160 may receive control signals and data from an external device.

The memory 150 may store various data or programs for driving and controlling the ultrasonic diagnostic apparatus 100, input ultrasonic data and/or output ultrasonic data, ultrasonic images, applications, and the like.

The input interface 170 may receive user inputs for controlling the ultrasonic diagnostic apparatus 100, and may include a keyboard, buttons, a keypad, a mouse, a trackball, a toggle switch, a knob, a touch pad, a touch screen, a microphone, an action input device, a biometric input device, and the like. For example, the user input may include an input for manipulating a button, a keypad, a mouse, a trackball, a toggle switch, or a knob, an input for touching a touch pad or a touch screen, a voice input, a motion input, and a biological information input (e.g., iris recognition or fingerprint recognition), but the exemplary embodiments are not limited thereto.

An example of the ultrasonic diagnostic apparatus 100 according to the present exemplary embodiment is described below with reference to fig. 2a, 2b, and 2 c.

Fig. 2a, 2b, and 2c are diagrams illustrating an ultrasonic diagnostic apparatus according to an exemplary embodiment.

Referring to fig. 2a and 2b, the ultrasonic diagnostic apparatuses 200a and 200b may include a main display 221 and a sub-display 222 at least of the main display 221 and the sub-display 222 may include a touch screen.

The main display 221 and the sub-display 222 may display the ultrasound image and/or various information processed by the ultrasound diagnostic apparatus 200a or 200 b. The main display 221 and the sub-display 222 may provide a Graphical User Interface (GUI) to receive user input of data for controlling the ultrasonic diagnostic apparatus 200a or 200 b. For example, the main display 221 may display an ultrasound image, and the sub-display 222 may display a control panel for controlling the display of the ultrasound image as a GUI. The sub-display 222 may receive an input of data for controlling the display of the image through a control panel displayed as a GUI. The ultrasonic diagnostic apparatus 200a or 200b can control the display of the ultrasonic image on the main display 221 by using the input control data.

Referring to fig. 2b, the ultrasonic diagnostic apparatus 200b may include a control panel 230. The control panel 230 may include buttons, a trackball, a toggle switch, or a knob, and may receive data for controlling the ultrasonic diagnostic apparatus 200b from a user. For example, the control panel 230 may include a Time Gain Compensation (TGC) button 241 and a freeze button 242. The TGC button 241 is used to set a TGC value for each depth of the ultrasound image. In addition, when the input of the freeze button 242 is detected during scanning of the ultrasound image, the ultrasound diagnostic apparatus 200b may hold the frame image displayed at the point in time.

Buttons, trackballs, toggle switches, and knobs included in the control panel 230 may be provided as GUIs to the main display 221 or the sub-display 222.

Referring to fig. 2c, the ultrasonic diagnostic apparatus 200c may include a portable device. Examples of the portable ultrasonic diagnostic device 200c may include, for example, a smart phone (including a probe and an application), a laptop computer, a Personal Digital Assistant (PDA), or a tablet PC, but the exemplary embodiments are not limited thereto.

The ultrasonic diagnostic apparatus 200c may include the probe 20 and the body 223 the probe 20 may be connected to the side of the body 223 by a cable or wirelessly connected to the side of the body 223 may include the touch screen 224 may display ultrasonic images, various information processed by the ultrasonic diagnostic apparatus 200c, and a GUI.

Fig. 3 is a block diagram illustrating components of an ultrasonic diagnostic apparatus 300 according to an embodiment of the present disclosure.

Referring to fig. 3, the ultrasonic diagnostic apparatus 300 may include a probe 310, a processor 320, and a display 330 according to an embodiment, the ultrasonic diagnostic apparatus 300 may include the probe 310 and the processor 320 in addition to the display 330, furthermore, according to another embodiment, the ultrasonic diagnostic apparatus 300 may include components other than those shown in fig. 1.

The probe 310 transmits ultrasonic waves to a region of interest (ROI) of a subject and detects echo signals. In addition, the probe 310 causes a displacement in the ROI. In an embodiment of the present disclosure, the probe 310 may emit a focused beam onto the subject to cause displacement of the tissue of the subject. The probe 310 can control a sequence of ultrasonic signal outputs from piezoelectric elements arranged in an array to generate and output a focused ultrasonic beam. When the focused beam is emitted onto the subject, the focused beam causes deformation according to the movement of the tissue in the axial direction, thereby causing displacement of the tissue. The probe 310 may propagate shear waves due to the displacement of tissue in the object. When a displacement is caused in the subject, the ultrasonic diagnostic apparatus 300 may acquire an elastic mode ultrasonic image by scanning the ultrasonic image.

The processor 320 may be composed of or more hardware units, in an embodiment, the processor 320 may be composed of hardware units including a memory for storing at least of computer programs, algorithms, and application data, and a processor for processing the programs, algorithms, or application data stored in the memory, for example, the processor 320 may be composed of a processor including at least of a Central Processing Unit (CPU), a microprocessor, and a graphic processing unit, in which case the memory and the processor may be formed as a single chip, but are not limited thereto, the processor 320 may be implemented as or more software modules generated by executing program codes stored in the memory, according to another embodiment.

In this case, the processor 320 may correspond to at least of the controller 120 and the image processor 130 of FIG. 1, or a combination thereof.

According to an embodiment, the probe 310 may transmit an th ultrasound signal to the object, and the processor 320 may obtain a reference ultrasound image by using a th ultrasound echo signal reflected from the object, the probe 310 may transmit a second ultrasound signal to the object after transmitting the focused ultrasound beam onto the object, and the processor 320 may respectively obtain a plurality of shear wave images captured at a plurality of time points based on the second ultrasound echo signal reflected from the object.

The processor 320 may calculate the displacement of the sub-tissue in the object corresponding to the plurality of measurement points, respectively, by comparing each of the plurality of shear wave images with the reference ultrasound image, hi an embodiment, the processor 320 may calculate the displacement of the sub-tissue in the object by performing an autocorrelation or cross-correlation between the reference ultrasound image and each of the shear wave images, hi accordance with another embodiment, the displacement may be calculated by using a differential image between the ultrasound image obtained before the object is moved and the ultrasound image obtained after the object is moved (i.e., between the shear wave image and the reference ultrasound image) or by differentiating the obtained shear wave image with respect to time, hi accordance with an embodiment, the processor 320 may include a module such as a displacement calculator.

The processor 320 may measure the shear wave arrival time at a plurality of measurement points, respectively, which are spaced apart from the focal point, to which the focused light beam is emitted, by a preset distance, respectively. In an embodiment, the processor 320 may measure the shear wave arrival time from the displacement of the plurality of sub-tissues in the ROI, and specifically, the processor 320 may determine a time when the magnitude of the variation of the displacement of the sub-tissues is maximum as the shear wave arrival time. The processor 320 may calculate a time point when the displacement of the tissue in the object located at each of the plurality of measurement points is maximum, the measurement point being spaced apart from the focal point by a preset distance, and determine the calculated time point as a shear wave arrival time of each of the plurality of measurement points. In this case, the processor 320 may differentiate the plurality of detected tissue displacements with respect to time, calculate axial velocities with respect to time for the differentiated tissue displacements, respectively, and determine time points when the calculated axial velocities reach their maximum values as shear wave arrival times at the plurality of measurement points, respectively.

According to another embodiment, processor 320 may measure shear wave arrival times by calculating, via cross-correlation, a time delay between a displacement signal according to a change over time at measurement points of the plurality of measurement points and a displacement signal at another measurement point adjacent to the measurement point.

According to an embodiment, the processor 320 may determine an average of shear wave arrival times respectively measured at a plurality of measurement points as an th average shear wave arrival time, determine an average of differences as a second average shear wave arrival time (each difference being a difference between shear wave arrival times at two adjacent points of the plurality of measurement points), and detect an occurrence of reverberation by comparing a preset threshold with a value obtained by dividing a th average shear wave arrival time by the second average shear wave arrival time, in which case the processor 320 may detect the occurrence of reverberation when the th average shear wave arrival time is greater than a preset reference time.

According to an embodiment, the processor 320 may calculate the shear wave speed by dividing an average of distances of the plurality of measurement points by an average of shear wave arrival times measured at the plurality of measurement points, respectively, calculate the second shear wave speed by dividing a distance between two adjacent points of the plurality of measurement points by a difference between the shear wave arrival times measured at the two adjacent measurement points, respectively, and detect the occurrence of reverberation based on the th shear wave speed and the second shear wave speed.

According to an embodiment, the processor 320 may calculate a shear wave velocity ratio and obtain a reliability measure indicator based on the calculated shear wave velocity ratio.

The display 330 may display an operation state, an ultrasonic image, a UI, etc. of the ultrasonic diagnostic apparatus 300, for example, the display 330 may be constructed of at least physical devices including a Cathode Ray Tube (CRT) display, a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP) display, an Organic Light Emitting Display (OLED), a Field Emission Display (FED), a Light Emitting Diode (LED) display, a Vacuum Fluorescent Display (VFD), a Digital Light Processing (DLP) display, a Flat Panel Display (FPD), a three-dimensional (3D) display, and a transparent display, but is not limited thereto.

According to an embodiment, the display 330 may display information about the detected reverberation via a UI including at least terms of phrases, sentences, symbols, and colors.

According to an embodiment, the display 330 may display information about the detected reverberation together with an ultrasound image of the object in which case the ultrasound diagnostic apparatus 300 may operate in an elastic mode and the ultrasound image may be an elastic mode ultrasound image.

According to an embodiment, the ultrasonic diagnostic apparatus 300 may further include a speaker outputting information on the detected reverberation in the form of sound including at least of a beep, a melody, and a voice as a component thereof.

Reference numeral 300 is used hereinafter collectively to refer to an ultrasonic diagnostic apparatus according to an embodiment of the present disclosure. However, although reference numerals such as 100, 200a, 200b and 200c are used to denote the ultrasonic diagnostic apparatus according to the embodiments related to the specific drawings, other embodiments are not excluded and those having ordinary skill in the art will understand that the features of the embodiments can also be applied to other embodiments to which the features are applicable. A method of operating the ultrasonic diagnostic apparatus 300 will now be described with reference to fig. 4.

Fig. 4 is a flowchart of a method of detecting occurrence of reverberation in an ROI and displaying information on the reverberation performed by the ultrasonic diagnostic apparatus 300 according to an embodiment of the present disclosure.

In operation S410, the ultrasonic diagnostic apparatus 300 induces shear waves in the subject by emitting a focused ultrasonic beam onto the ROI of the subject. Referring to fig. 3 and 4, the probe 310 may cause displacement of the tissue of the subject by emitting a focused ultrasound beam onto the ROI of the subject. In this case, the focused ultrasound beam may comprise a push pulse. The region of the ROI illuminated by the focused ultrasound beam is called the focal point.

In operation S420, the ultrasonic diagnostic apparatus 300 obtains ultrasonic images of the object at a plurality of time points. When a focused ultrasonic beam is emitted onto a subject via the probe 310, a tissue displacement of the subject is caused at the focal point where the focused ultrasonic beam is focused. The focused ultrasound beam propagates in the depth direction, and the shear wave propagates in the direction perpendicular to the displacement and in the axial direction (i.e., from the point along the axis where the displacement occurs to both sides). Subsequently, the probe 310 transmits an ultrasonic signal such as a plane wave to the subject, and the processor 320 obtains shear wave images captured at a plurality of points in time by using the ultrasonic echo signal reflected from the subject. For example, shear wave images may be obtained at a frame rate of several thousand frames per second (fps) (exceeding 5000 fps).

In operation S430, the ultrasonic diagnostic apparatus 300 measures shear wave arrival times at a plurality of measurement points within the ROI, respectively. According to the embodiment, the ultrasonic diagnostic apparatus 300 may measure a time point when the magnitude of the change of each of the plurality of tissue displacements is maximum (the tissue displacements respectively correspond to the plurality of measurement points at the preset distance from the focal point), and determine the time point as the shear wave arrival time. Referring to the description with respect to fig. 3, processor 320 may calculate the displacement due to the motion of the sub-tissue in the object by comparing each shear wave image of the plurality of shear wave images with the reference ultrasound image.

According to the embodiment, the ultrasonic diagnostic apparatus 300 may differentiate the tissue displacement in the plurality of shear wave images with respect to time, calculate axial velocities with respect to time for the differentiated tissue displacements, respectively, and determine time points when the calculated axial velocities are maximum as shear wave arrival times at the plurality of measurement points, respectively.

According to an embodiment, the ultrasonic diagnostic apparatus 300 may determine an average of shear wave arrival times respectively measured at a plurality of measurement points as an th average shear wave arrival time, determine an average of differences as a second average shear wave arrival time (each difference being a difference between shear wave arrival times at two adjacent points of the plurality of measurement points), and detect occurrence of reverberation by comparing a preset threshold with a value obtained by dividing a th average shear wave arrival time by the second average shear wave arrival time, in which case, the ultrasonic diagnostic apparatus 300 may detect the occurrence of reverberation when the th average shear wave arrival time is greater than a preset reference time.

According to an embodiment, the ultrasonic diagnostic apparatus 300 may calculate the shear wave speed by dividing an average value of distances of a plurality of measurement points by an average value of shear wave arrival times at the plurality of measurement points, calculate the second shear wave speed by dividing a distance between two adjacent points of the plurality of measurement points by a difference between the shear wave arrival times respectively measured at the two adjacent measurement points, and detect occurrence of reverberation based on the shear wave speed and the second shear wave speed.

According to an embodiment, the ultrasonic diagnostic apparatus 300 may display information on the detected reverberation on the display 330, the ultrasonic diagnostic apparatus 300 may display the information on the detected reverberation via a UI including at least items of phrases, sentences, symbols, and colors, the ultrasonic diagnostic apparatus 300 may display the information on the detected reverberation together with the ultrasonic image of the object.

Although not shown as a separate operation in fig. 4, the ultrasonic diagnostic apparatus 300 may output information on the detected reverberation in the form of sounds including at least of a beep, a melody, and a voice.

Generally, during ultrasound elastography, reverberation occurs when an ultrasound signal transmitted to a subject is reflected between the surface of the probe 310 and tissue or between tissues. The reverberation can appear as a relatively bright blur band in an ultrasound image (e.g., a B-mode image). When measuring elasticity of an object having a thick fat layer, such as an obese patient, relatively severe reverberation may occur due to reflection between the surface of the probe and tissue or between tissues, otherwise, an elasticity value may be accurately measured due to mild reverberation. When reverberation occurs, the accuracy of RMI tends to decrease, and thus, a user cannot obtain a reliable elasticity value.

According to the embodiment described with reference to fig. 3 and 4, the ultrasonic diagnostic apparatus 300 may propagate shear waves in an ROI of a subject, measure shear wave arrival times at a plurality of measurement points, detect reverberation based on the shear wave arrival times, and display information on the detected reverberation, thereby improving the accuracy of elasticity measurement, furthermore, the ultrasonic diagnostic apparatus 300 may display the reverberation information together with the ultrasonic image , so that when reverberation occurs, a user may manipulate the probe 310 to prevent severe reverberation or may move the ROI to a region of mild reverberation, thereby facilitating elasticity measurement and improving user convenience.

Fig. 5 is a diagram for explaining a method of causing displacement of tissue within an ROI and calculating the displacement, which is performed by the ultrasonic diagnostic apparatus 300, according to an embodiment of the present disclosure. Fig. 6 is a flowchart of a method of measuring shear wave arrival time by tissue displacement within an ROI performed by the ultrasonic diagnostic apparatus 300 according to an embodiment of the present disclosure. A method of operating the ultrasonic diagnostic apparatus 300 will now be described in detail with reference to fig. 5 and 6.

Referring to fig. 5 and 6, the ultrasonic diagnostic apparatus 300 transmits -th ultrasonic signals 512 as reference pulses to the ROI of the subject and receives -th ultrasonic echo signals 514 reflected in response to the -th ultrasonic signals 512, and further, the ultrasonic diagnostic apparatus 300 generates a reference ultrasonic image 510 of the ROI based on the received -th ultrasonic echo signals 514 (operation S610).

According to an embodiment, when the ultrasonic diagnostic device 300 receives the th ultrasonic echo signal 514, the processor (320 of fig. 3) may generate the reference ultrasonic image 510 of the ROI based on the th ultrasonic echo signal 514 the reference ultrasonic image 510 may be an image showing the position of tissue before applying a force to the ROI the reference ultrasonic image 510 may be a B-mode image or an M-mode image of the ROI.

In operation S620, the ultrasonic diagnostic apparatus 300 transmits the second ultrasonic signal 530 as a push pulse to the focal point 520 within the ROI via the probe 310 and propagates the shear wave 532 due to the displacement generated in the tissue within the ROI. The second ultrasonic signal 530 may be a focused ultrasonic beam.

When a second ultrasound signal 530 is transmitted to the focal point 520 within the ROI, shear waves 532 may be generated in tissue located within the ROI. For example, a focused ultrasound beam emitted in the Z-axis direction toward the ROI may push tissue in the direction of the ultrasound pulse (axial direction), i.e., in the X-axis direction. Movement of tissue at focal point 520 in an axial direction may cause movement of adjacent tissue in an X-axis (axial) direction. When tissue adjacent to focal point 520 moves in the same direction, the motion may be sequentially propagated to tissue adjacent to the moving tissue. In this case, the force of the ultrasonic pulse that moves the tissue may be referred to as acoustic force (acoustic force).

When motion propagates to adjacent tissue, the acoustic force applied to focal point 520 may generate a wave that propagates away from focal point 520 as the origin in a direction (lateral direction) orthogonal to the direction of the ultrasonic pulse. A wave propagating in a direction orthogonal to the direction of the ultrasonic pulse may be referred to as a shear wave 532.

The propagation velocity of the shear wave 532 may be determined from the stiffness, young's modulus or shear modulus of the tissue. For example, the propagation velocity of the shear wave 532 may vary from 1m/s to 10m/s depending on the stiffness of the tissue. Further, the more rigid the tissue, the higher the propagation velocity of the shear wave 532 in the tissue.

Further, the relationship between the propagation velocity of the shear wave 532 through the tissue and the stiffness of the tissue can be shown in the following equation.

G＝ρ×C²

In this regard, G is the tissue stiffness, ρ is the tissue density, and C is the propagation velocity of the shear wave 532. The tissue density ρ may be considered a constant value in the ROI and may typically be a known value. Thus, tissue stiffness, which is indicative of the stiffness of the tissue, can be detected as a quantitative value by measuring the propagation velocity of the shear wave 532 through the tissue.

The shear wave 532 may be detected by measuring the displacement of the tissue in the direction of the ultrasonic pulse (axial direction). The displacement of the tissue may be the distance the tissue has moved in the axial direction relative to the reference ultrasound image 510. Further, the propagation velocity of the shear wave 532 through the sub-tissue in the ROI may be calculated based on a point in time when the displacement of the sub-tissue and the displacement of the tissue around the sub-tissue are maximum.

In operation S630, the ultrasonic diagnostic apparatus 300 transmits the third ultrasonic signal 540 as a tracking pulse to the ROI in which the shear wave 532 propagates and receives the third ultrasonic echo pulse 562. Referring to fig. 5, to detect displacement of tissue by acoustic forces, processor 320 may transmit a third ultrasound signal 540 to the ROI. In this case, in order to more accurately measure the propagation velocity of the shear wave 532, the processor 320 may transmit the plane wave as the third ultrasound signal 540 to the ROI. When a plane wave is transmitted as the third ultrasonic signal 540, the ultrasonic diagnostic apparatus 300 can capture the shear wave 532 at a frame rate of several thousand fps.

After transmission to the tissue, the third ultrasound signal 540 may be scattered by scatterers 560 in the tissue within the ROI. The third ultrasonic signal 540 scattered by the scatterer 560 may be reflected to the probe 310. In this case, the third ultrasonic signal 540 scattered by the scatterer 560 may be referred to as a third ultrasonic echo pulse 562.

In operation S640, the ultrasonic diagnostic apparatus 300 generates a shear wave image 550 of the ROI based on the received third ultrasonic echo pulse 562. Upon receiving the third ultrasound echo pulse 562, the processor 320 may generate an ultrasound image of the ROI. The image in the ultrasound image generated based on the third ultrasound echo pulse 562 that includes shear waves may be referred to as a shear wave image 550. When a plane wave is transmitted as the third ultrasound signal 540, the processor 320 may generate a shear wave image 550 at a frame rate of several thousand fps.

In operation S650, the ultrasound diagnostic device 300 detects tissue displacement in the ROI by comparing the shear wave image 550 with the reference ultrasound image 510 according to an embodiment, the processor 320 may shift the reference ultrasound image 510 and the shear wave image 550 down to baseband, respectively, and convert the results to demodulated data in which case the processor 320 may include a computation module for computing a phase difference between the reference ultrasound image 510 and the shear wave image 550 based on the demodulated data and determining displacement of the tissue by converting the computed phase difference to a distance of tissue movement in the ROI according to another embodiment, the processor 320 may interpolate the reference ultrasound image 510 and the shear wave image 550 and then detect a plurality of tissue displacements by computing a time delay in a scan line centered at the position of each axis via cross-correlation.

In operation S660, the ultrasonic diagnostic apparatus 300 measures a shear wave arrival time according to the detected tissue displacement according to an embodiment, the processor 320 may measure a shear wave arrival time according to a displacement of a plurality of tissues respectively located at a plurality of measurement points, the plurality of measurement points being spaced apart from the focal point 520 by a preset distance in an axial direction, in this case, the processor 320 may determine a time point when an amplitude of a change of each of the plurality of tissue displacements is maximum as the shear wave arrival time, to achieve the point, the processor 320 may differentiate the plurality of detected tissue displacements with respect to time, calculate an axial velocity with respect to time respectively for the differentiated tissue displacements, and determine a time point when the calculated axial velocity reaches its maximum as the shear wave arrival time respectively.

According to another embodiment, processor 320 measures shear wave arrival time by calculating, via cross-correlation, a time delay between the displacement signal as a function of time at the measurement point at which the shear wave arrival time is to be measured and the displacement signal at another measurement point, which another measurement point is adjacent to the measurement point or to the location where the shear wave was originally generated.

Fig. 7a is a graphical representation of the coordinates of the positions of a plurality of scan lines in an ROI and the direction of focus of a focused ultrasound beam applied to the ROI in the depth direction.

Referring to fig. 7a, the probe 310 may transmit a focused ultrasonic beam including a push pulse to the ROI of the subject in a depth (Z-axis) direction for a preset period of time. In this case, the shear wave may propagate in the axial (X-axis) direction due to displacement caused by the motion of the tissue in the ROI. The shear wave propagates away from the focal point where the focused ultrasound beam is transmitted in both X-axis directions. However, for convenience of explanation, only the positive X-axis direction (+ X direction) is shown in fig. 7a, and the negative X-axis direction (-X direction) is not shown.

A plurality of scanning lines (x)₁、x₂、x₃、x₄And x₅) Are arranged in the ROI such that they are spaced apart from the ultrasonic focus O by preset distances in the axial (X-axis) direction, respectively.Multiple scanning lines x₁、x₂、x₃、x₄And x₅May each extend in the depth (Z-axis) direction.

th scan line x₁May be spaced from the ultrasonic focus O by a distance d of _lFor example, distance d of _lMay be 5 mm-this is only an example of a numerical value and the th distance d₁Not limited thereto. Multiple scanning lines x₁、x₂、x₃、x₄And x₅Are spaced apart from each other by a second distance d₂For example, as the th scan line x₁And a second scanning line x₂Second distance d of the distance between₂May be 1.44 mm. This is merely an example of a numerical value, and the second distance d₂Not limited thereto.

Multiple scanning lines x₁、x₂、x₃、x₄And x₅May respectively include a plurality of measurement points arranged with a certain depth value in the axial (X-axis) direction. According to the embodiment, the ultrasonic diagnostic apparatus 300 may measure the shear wave arrival time from the displacements of the plurality of tissues corresponding to the plurality of measurement points in the ROI, respectively. The measurement of shear wave arrival time will now be described in detail with reference to figure 7 b.

Fig. 7b is a diagram for explaining a method of calculating a shear wave propagation velocity at a plurality of measurement points within the ROI, which is performed by the ultrasonic diagnostic apparatus 300, according to an embodiment of the present disclosure.

Referring to fig. 7b, the processor 320 of the ultrasonic diagnostic apparatus 300 may detect a displacement of the ROI based on a displacement of the tissue generated by the acoustic force and measure a shear wave arrival time based on the detected displacement. Shear wave 740 may propagate in an axial direction based on displacement of tissue. According to an embodiment, the processor 320 may compare the shear wave image 730 with the reference ultrasound image 720 to calculate displacements of a plurality of sub-tissues 711 to 715 of the tissue within the ROI, the plurality of sub-tissues 711 to 715 being arranged at the plurality of scan lines x, respectively₁、x₂、x₃、x₄And x₅At the corresponding position.

For example, processor 320 may detect th subgroup in reference ultrasound image 720 based on the cross-correlationThe position to which the tissue 711 moves in the th shear wave image 731 the th sub-tissue 711 may be the tissue located within the ROI that is arranged with the th scan line x₁Processor 320 may scan line x via ₁The processor 320 may detect a time point when the displacement of the th sub-tissue 711 is maximum based on the calculated displacement, the processor 320 may calculate a time point t when the displacement of the th sub-tissue 711 is maximum₁In this case, the processor 320 may set the time point t when the displacement of the th sub-tissue 711 is maximum as the shear wave 740 reaches the th sub-tissue 711₁Determined as for the th scan line x₁Time of arrival t of shear wave₁。

In the same manner as the above-described method, the processor 320 may measure the time points t when the shear waves respectively reach the plurality of sub-tissues 711 to 715 in the plurality of shear wave images 731 to 735₁To t₅And based on the point in time t₁To t₅To determine for a plurality of scan lines x₁To x₅Time of arrival of the shear wave.

Fig. 7c is a graph showing the relationship between shear wave arrival time and tissue displacement measured by the ultrasonic diagnostic apparatus 300 at each of a plurality of measurement points according to an embodiment of the present disclosure.

Referring to fig. 7b and 7c, the th sub-tissue 711 is displaced at a time point t₁Is at a maximum, thus at a point in time t₁Determined as the th shear wave arrival time (i.e., for scan line x of )₁Point of arrival time of the shear wave). Similarly, the displacement of the second sub-tissue 712 is at the point in time t₂Is at a maximum, thus at a point in time t₂Is determined as the second shear wave arrival time (i.e., for the second scan line x)₂Point of arrival time of the shear wave).

Referring to fig. 7a to 7c, the processor 320 may determine the distance d based on the th distance₁And a second distance d₂Calculating the velocity of the shear wave 740, a plurality of scan lines x₁To x₅Is spaced from the focal point O by a th distance d₁A second distance d₂For a plurality of scanning lines x₁To x₅Is measured in the scanning direction. This will be described in detail below with reference to fig. 9 and 10.

Fig. 8 is a flowchart of a method performed by the ultrasound diagnostic apparatus 300 of detecting the occurrence of reverberation based on shear wave arrival times at a plurality of measurement points within the ROI according to an embodiment of the present disclosure.

In operation S810, the ultrasonic diagnostic apparatus 300 determines an average value of shear wave arrival times measured at a plurality of measurement points, respectively, as an th average shear wave arrival time t_avg1According to the embodiment, the ultrasonic diagnostic apparatus 300 may calculate the th average shear wave arrival time t by adding all the time points when the displacement of the sub-tissue detected at the plurality of measurement points, respectively, is maximum and then dividing the resultant sum by the number n of measurement points according to the following equation_avg1。

Referring to fig. 7a to 7c, the ultrasonic diagnostic apparatus 300 may determine the ultrasonic diagnosis by comparing all time points (i.e., th shear wave arrival time t) when the displacement of the sub-tissue detected at the plurality of measurement points, respectively, reaches its maximum value₁To a fifth shear wave arrival time t₅) Add and divide the resulting sum by 5 (i.e., the number of measurement points) to calculate the th average shear wave arrival time t_avg1Wherein the measuring points are at a plurality of scanning lines x along the depth direction₁To x₅Are separated in the axial direction at the same depth.

In operation S820, the ultrasonic diagnostic apparatus 300 determines an average value of the differences as a second average shear wave arrival time t_avg2Each difference is the difference between the arrival times of the shear wave at two adjacent points in the plurality of measurement points. According to an embodiment, the ultrasonic diagnostic apparatus 300 may determine the phase difference by adding all the differences between the arrival times of the shear waves at two adjacent points of the plurality of measurement points and dividing the resulting sum by the two phases according to the following equationThe logarithm of adjacent measurement points (i.e., n-1) to calculate a second average shear wave arrival time t_avg2。

Referring to fig. 7a to 7c, the ultrasonic diagnostic apparatus 300 may calculate the second average shear wave arrival time t by performing the following operations_avg2: all differences between the shear wave arrival times at two adjacent points of the plurality of measurement points (e.g. second shear wave arrival time t)₂And th shear wave arrival time t₁Difference t between₂-t₁Third shear wave arrival time t₃And a second shear wave arrival time t₂Difference t between₃-t₂… … and a fifth shear wave arrival time t₅And fourth shear wave arrival time t₄Difference t between₅-t₄) Add up and then divide the resulting sum by the logarithm of two adjacent measurement points (i.e., 4 ═ 5-1).

In operation S830, the ultrasonic diagnostic apparatus 300 averages the arrival time t of the shear wave by _avg1Divided by the second mean shear wave arrival time_tavg2To calculate the shear wave arrival time ratio t_ratio. In an embodiment, the shear wave arrival time ratio t may be calculated according to the following equation_ratio。

In operation S840, the ultrasonic diagnostic apparatus 300 compares the shear wave arrival time ratio t_ratioThe value of the threshold α may be any value set according to the type, specification, etc. of the ultrasonic diagnostic apparatus 300, according to an embodiment, the value of the threshold α may be set based on a user input.

For example, the value of the threshold α may be 20, however, the value of the threshold α is not limited to the above.

In operation S840, when the shear wave arrival time ratio t_ratioThe ultrasonic diagnostic apparatus 300 detects reverberation when the value greater than the threshold α (operation S850.) according to an embodiment, when the shear wave arrival time ratio t is determined_ratioWhen the ratio is larger than the value of the threshold, the ultrasonic diagnostic apparatus 300 may determine that reverberation has occurred due to a fat layer or the like in the ROI.

When shear wave arrival time ratio t_ratioLess than the threshold α, the ultrasonic diagnostic apparatus 300 does not detect reverberation (operation S860)_ratioLess than the threshold value α, the ultrasonic diagnostic apparatus 300 can determine this as an elastic environment in which reverberation does not occur.

Although fig. 8 shows a case where the ultrasonic diagnostic apparatus 300 averages t according to the arrival times of the shear waves at a plurality of measurement points_avg1And the average value t of the differences between two adjacent ones of the measurement points_avg2According to another embodiment, when the th average shear wave arrival time t_avg1The ultrasonic diagnostic apparatus 300 may detect reverberation above the preset threshold β in this case, the threshold β may be any value that varies according to the frame rate of the shear wave image (730 of fig. 7 b).

Although not shown in fig. 8, the ultrasonic diagnostic apparatus 300 may be configured by averaging the th average shear wave arrival time t_avg1According to another embodiment, the ultrasonic diagnostic apparatus 300 can detect reverberation by comparing the th average shear wave arrival time t_avg1According to another embodiment, the ultrasonic diagnostic apparatus 300 can detect reverberation by comparing the measurement point ( scan line x of fig. 7 a) that is closest to the focus of the ultrasonic beam₁) At a shear wave arrival time t₁And compared to a preset threshold β to detect reverberation.

Fig. 9 shows an -th wavefront plot 910 and a second wavefront plot 920 of shear wave arrival times measured by the ultrasonic diagnostic apparatus 300 at a plurality of measurement points, respectively, according to an embodiment of the present disclosure.

The -th and 920-th wavefront plots 910 and 920, respectively, of fig. 9 are shown with respect to a scan line x extending in the depth (Z-axis) direction and separated from each other in the axial direction₁To x₅ wavefront plot 910 and second wavefront plot 920 show shear wave arrival times when no reverberation occurs and shear wave arrival times when reverberation occurs, respectively wavefront plot 910 and second wavefront plot 920 show capture of shear wave images at 6250fps, however, the values indicated on the wavefront plot 910 and second wavefront plot 920, respectively, are merely examples and embodiments of the present disclosure are not limited to capture and obtain shear wave images at 6250 fps.

The th wavefront plot 910 shows when multiple scan lines x_lTo x₅At a measurement point of 63mm, e.g. th shear wave arrival time t₁To a fifth shear wave arrival time t₅May be approximately 5.44ms, 6.72ms, 8.32ms, 9.28ms, and 10.88ms, respectively. The above values are exemplary.

Referring to fig. 8 and 9, the ultrasonic diagnostic apparatus 300 may determine the arrival time t of the th shear wave in the th wavefront graph 910 by₁To a fifth shear wave arrival time t₅All added and the resulting sum divided by 5 to calculate the th average shear wave arrival time t_avg1(operation S810.) in this case, the th average shear wave arrival time t_avg1The value of (5.44+6.72+8.32+9.28+ 10.88)/5-8.128 ms may be calculated.

Further, the ultrasonic diagnostic apparatus 300 may determine the second average shear wave arrival time t by calculating the average of the differences between the shear wave arrival times at two adjacent points in the measurement points_avg2(operation S820.) in the th wavefront plot 910, the second shear wave arrival time t₂And th shear wave arrival time t₁Difference between them, third shear wave arrival time t₃And a second shear wave arrival time t₂Difference between, fourth shear wave arrival time t₄With a third shear wave toTo time t₃The difference between and the fifth shear wave arrival time t₅And fourth shear wave arrival time t₄The sum of the differences is 5.44ms and the second average shear wave arrival time t_avg2Can be calculated as 1.36ms by dividing 5.44ms by 4.

In the th wavefront plot 910, the shear wave arrival time ratio t_ratioCan be calculated as 5.976. The ultrasonic diagnostic apparatus 300 may compare the shear wave arrival time t_ratioThe comparison with the preset threshold α is made (operation S840) — according to the embodiment, since the value of the threshold α is 20, the ultrasonic diagnostic apparatus 300 does not detect reverberation by using the value from the th wavefront graph 910 (operation S850).

The second wavefront plot 920 shows when multiple scan lines x are present_lIt can be seen that the shear wave arrival times in the second wavefront plot 920 are arranged at relatively narrow intervals along the axial (X-axis) direction compared to the shear wave arrival times in the wavefront plot 910₁To a fifth shear wave arrival time t₅May be about 9.92ms, 10.56ms, 10.88ms, 11.22ms, and 11.84ms, respectively. The above values are exemplary.

Similarly, referring to fig. 8 and 9, the ultrasonic diagnostic apparatus 300 may determine the arrival time t of the th shear wave in the second wavefront graph 920 by comparing the arrival time t of the shear wave in the second wavefront graph 920₁To a fifth shear wave arrival time t₅All added and the resulting sum divided by 5 to calculate the th average shear wave arrival time t_avg1(operation S810.) in the second wavefront plot 920, the th average shear wave arrival time t_avg1The value of (9.92+10.56+10.88+11.22+ 11.84)/5-10.884 ms may be calculated.

In addition, the ultrasonic diagnostic apparatus 300 may determine the second average shear wave arrival time t in the second wavefront plot 920_avg2(operation S820). In the second wavefront plot 920, the second shear wave arrival time t₂And th shear wave arrival time t₁Difference between them, third shear wave arrival time t₃And a second shear wave arrival time t₂Difference between, fourth shear wave arrival time t₄And third shear wave arrival time t₃The difference between and the fifth shear wave arrival time t₅And fourth shear wave arrival time t₄The sum of the differences is 1.92ms and the second average shear wave arrival time t_avg2Can be calculated as 0.48ms by dividing 1.92ms by 4.

In the second wavefront plot 920, the shear wave arrival time ratio t_ratioCan be calculated as 22.675. The ultrasonic diagnostic apparatus 300 may compare the shear wave arrival time t_ratioThe comparison with the preset threshold α is made (operation S840) — according to the embodiment, since the value of the threshold α is 20, the ultrasonic diagnostic apparatus 300 detects reverberation by using the value from the second wavefront graph 920 (operation S850).

Fig. 10 is a flowchart of a method of detecting occurrence of reverberation based on shear wave velocities calculated at a plurality of measurement points within an ROI performed by the ultrasonic diagnostic apparatus 300 according to an embodiment of the present disclosure.

In operation S1010, the ultrasonic diagnostic apparatus 300 calculates the th shear wave velocity swv by using an average of distances from a plurality of measurement points to the focal point and an average of shear wave arrival times measured at the plurality of measurement points, respectively₁According to an embodiment, the ultrasonic diagnostic apparatus 300 may calculate the th shear wave velocity swv by using the following equation₁。

Referring to fig. 7a and 10, a scan line x is scanned from the focal point O to the th₁May be 5 mm. Further, the distance between two adjacent scan lines may be 1.44 mm. However, the above values are exemplary. In this case, the average distance of the plurality of measurement points may be calculated as (5+6.44+7.88+9.32+ 10.76)/5-7.88 mm.

Referring to fig. 9 and 10, in the th wavefront plot 910, the th average shear wave arrival time is 8.128ms, and therefore, the th shear wave velocity swv₁It can be calculated as 0.969 m/s. However, the above values areBy way of example. In the second wavefront plot 920, the second average shear wave arrival time t_avg2Is 10.884ms, so the shear wave velocity swv₁It can be calculated as 0.72 m/s.

In operation S1020, the ultrasonic diagnostic apparatus 300 calculates a second shear wave velocity swv by using a difference between a distance between two adjacent points of the plurality of measurement points and shear wave arrival times respectively measured at the two adjacent measurement points₂. According to an embodiment, the ultrasonic diagnostic apparatus 300 may calculate the second shear wave velocity swv by using a difference between a distance between two arbitrary adjacent measurement points of the plurality of measurement points and a shear wave arrival time according to the following equation₂。

According to another embodiment, the ultrasonic diagnostic apparatus 300 may calculate a plurality of shear wave velocities by using a difference between a distance between two adjacent points of the plurality of measurement points and a shear wave arrival time and determine an average of the shear wave velocities as the second shear wave velocity swv₂。

Referring to figures 9 and 10, the second shear wave arrival time t is shown in the wavefront plot 910₂And th shear wave arrival time t₁The difference between is 1.28ms, and thus, the second shear wave velocity swv₂It can be calculated as 1.125m/s for 1.44mm/1.28 ms. Similarly, as shown in the second wavefront plot 920, the second shear wave arrival time t₂And th shear wave arrival time t₁The difference between is 0.64ms, and thus, the second shear wave velocity swv₂It can be calculated as 1.44mm/0.64 ms-2.25 m/s. The above values are exemplary.

In operation S1030, the ultrasonic diagnostic apparatus 300 calculates a shear wave velocity ratio swv_ratioAnd the shear wave velocity ratio swv_ratioAnd comparing with a preset threshold value gamma. According to an embodiment, the ultrasonic diagnostic apparatus 300 may perform the ultrasonic diagnosis by converting the second shear wave velocity swv according to the following equation₂And the th shear wave velocity swv₁BetweenIs divided by the th shear wave velocity swv₁To calculate the shear wave velocity ratio swv_ratio。

The value of the threshold value γ may be any value set according to the type, specification, and the like of the ultrasonic diagnostic apparatus 300. According to an embodiment, the value of the threshold γ may be set based on user input.

For example, the value of the threshold γ may be 0.5. However, the value of the threshold value γ is not limited to the above value.

In operation S1030, when the shear wave velocity ratio swv_ratioWhen it is larger than the threshold value γ, the ultrasonic diagnostic apparatus 300 detects reverberation (operation S1040). According to an embodiment, when the shear wave velocity ratio swv calculated in operation S1030_ratioAbove 0.5, the ultrasonic diagnostic apparatus 300 can detect the occurrence of reverberation.

Referring to fig. 9 and 10, in the th wavefront plot 910, the shear wave velocity ratio swv_ratioCan be calculated as (1.125-0.969)/0.969-0.16 because of the shear wave velocity ratio swv calculated in the th wavefront plot 910_ratioLess than 0.5, the ultrasonic diagnostic apparatus 300 does not detect reverberation.

In the second wavefront plot 920, the shear wave velocity ratio swv_ratioCan be calculated as (2.25-0.72)/0.72-2.125. Because of the shear wave velocity ratio swv calculated in the second wavefront plot 920_ratioGreater than 0.5, the ultrasonic diagnostic apparatus 300 detects reverberation.

Fig. 11a and 11b are graphs for explaining a method of determining a value of RMI based on a shear wave velocity ratio, which is performed by the ultrasonic diagnostic apparatus 300, according to an embodiment of the present disclosure.

Referring to fig. 11a, the ultrasonic diagnostic apparatus 300 may calculate a shear wave velocity ratio and determine RMI based on the calculated shear wave velocity ratio. RMI is an index value indicating the quality of a shear wave elastography image and may be replaced with a Reliability Index (RI) or a cost function.

According to an embodiment, when the shear wave velocity ratio has a value greater than or equal to 0 but less than 0.5, the ultrasonic diagnostic apparatus 300 may determine the value of RMI to be 1. In this case, the reliability is 100%, which means that no reverberation occurs. When the shear wave velocity ratio has a value greater than 0.5, the ultrasonic diagnostic apparatus 300 may determine the value of RMI as 0. In this case, the reliability is 0%, which means that reverberation has occurred.

Referring to fig. 11b, when the shear wave velocity ratio has a value greater than or equal to 0 but less than 0.5, the ultrasonic diagnostic apparatus 300 may determine the value of RMI to be 1 (like fig. 11 a). However, when the shear wave velocity ratio has a value greater than or equal to 0.5 but less than 1, the ultrasonic diagnostic apparatus 300 may determine the value of RMI according to the following equation.

RMI＝-2×swv_ratio+2

For example, when the calculated shear wave velocity ratio is 0.7, the ultrasonic diagnostic apparatus 300 may determine the value of RMI to be 0.6. In this case, the reliability of shear wave elastography can be expected to be 60%. Further, the ultrasonic diagnostic apparatus 300 can detect that the case where the shear wave velocity ratio is 0.5 or more is an environment in which reverberation has occurred.

When the shear wave velocity ratio is greater than or equal to 1, the ultrasonic diagnostic apparatus 300 may determine the value of RMI as 0.

Fig. 12a and 12b are diagrams for explaining a method of displaying information on detected reverberation on the display 330 performed by the ultrasonic diagnostic apparatus 300 according to an embodiment of the present disclosure.

Referring to fig. 12a, the ultrasonic diagnostic apparatus 300 may display an ROI interface 1220 and a reverberation information interface 1230 on the display 330 together with an ultrasonic image 1210 of an object according to an embodiment, the ultrasonic image 1210 may be a B-mode image of the object, the ROI interface 1220 is displayed in the ultrasonic image 1210, and the ROI interface 1220 is a UI indicating a position of a ROI set in the object.

The reverberation information interface 1230 may be displayed with an interface for displaying elasticity values and depth values with RMI according to embodiments, the reverberation information interface 1230 may be displayed in different colors according to the value of RMI, for example, when the RMI has values of 0, 0.5, and 1, respectively, the reverberation information interface may be shown in red, green, and blue, respectively.

Although not shown in fig. 12a and 12b, the reverberation information interface 1230 may display the value of RMI as a percentage (%) according to an embodiment. For example, when the value of RMI is 0.6, the reverberation information interface 1230 may display the value of RMI as 60% after conversion to a percentage.

Referring to fig. 12b, the ultrasonic diagnostic apparatus 300 may display an ROI interface 1220 and a reverberation information interface 1240 on the display 330 together with an ultrasonic image 1210 of an object the reverberation information interface 1240 may display reverberation information as at least of a phrase, sentence, symbol, for example, when reverberation is detected, the reverberation information interface 1240 may display reverberation information as a phrase or sentence, such as "reverberation" or "reverberation detected".

According to an embodiment, the ultrasonic diagnostic apparatus 300 may provide reverberation information in the form of sound including at least of buzzes, melodies, and voices via the UI, for example, the ultrasonic diagnostic apparatus 300 may guide the user by saying "reverberation detected" voice, or may inform the user of the reverberation by sounding "beep-beep".

In the embodiment shown in fig. 12a and 12b, the ultrasonic diagnostic apparatus 300 may display information on the detected reverberation together with the ultrasonic image 1210 of the object, thereby allowing the user to more easily and conveniently detect the occurrence of reverberation, thus improving user convenience.

Embodiments of the present disclosure may be implemented as a software program comprising instructions stored in a computer-readable storage medium.

The computer may refer to a device capable of retrieving instructions stored in a computer-readable storage medium and performing operations according to the embodiment in response to the retrieved instructions, and may include the ultrasonic diagnostic apparatus 300 according to the embodiment.

The computer-readable storage medium may be provided in the form of a non-transitory storage medium. In this case, the term "non-transitory" merely means that the storage medium does not include a signal and is tangible, and the term does not distinguish data semi-permanently stored in the storage medium from data temporarily stored in the storage medium.

In addition, when provided, the ultrasonic diagnostic apparatus 300 or the method according to the embodiment may be included in a computer program product. The computer program product may be used to conduct a transaction between a seller and a buyer as a commodity.

The computer program product may include a software program and a computer readable storage medium having the software program stored thereon. For example, the computer program product may include a product obtained by a manufacturer of the ultrasound diagnostic apparatus or through an electronic market (e.g., Google PlayStore)^TMAnd App Store^TM) A product in the form of an electronically distributed software program (e.g., a downloadable application), for such electronic distribution, at least portions of the software program may be stored on a storage medium or may be temporarily generated.

In a system composed of a server and a terminal (e.g., an ultrasound diagnostic apparatus), the computer program product may include a storage medium of the server or a storage medium of the terminal. Alternatively, in the case where a third device (e.g., a smartphone) is connected to a server or a terminal through a communication network, the computer program product may include a storage medium of the third device. Alternatively, the computer program product may comprise the software program itself, which is transferred from the server to the terminal or the third device or from the third device to the terminal.

Alternatively, two or more of the server, the terminal, and the third device may execute the computer program product to perform the method according to the embodiments in a distributed manner.

For example, a server (e.g., a cloud server, an artificial intelligence server, etc.) may run a computer program product stored therein to control a terminal in communication with the server to perform a method according to embodiments of the present disclosure.

As another example, the third device may execute a computer program product to control a terminal in communication with the third device to perform the method according to the embodiments as a specific example, the third device may remotely control the ultrasound diagnostic apparatus 300 to transmit ultrasound signals to a subject and generate an image of an internal region of the subject based on information related to signals reflected from the subject.

As another example, a third apparatus may execute a computer program product to directly perform a method according to embodiments based on values received from an accessory (e.g., a probe of a medical device).

In a case where the third apparatus executes the computer program product, the third apparatus may download the computer program product from the server and execute the downloaded computer program product. Optionally, a third apparatus may execute a computer program product preloaded therein to perform a method according to an embodiment of the present disclosure.

Furthermore, although the embodiments of the present disclosure have been shown and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made therein by those having ordinary skill in the art to which the present disclosure pertains without departing from the spirit of the present disclosure as claimed in the claims, and these modifications should not be individually understood from the technical spirit or point of view of the present disclosure.