Ultrasonic imaging method and ultrasonic imaging system

Abstract

The invention discloses an ultrasonic imaging method and an ultrasonic imaging system, and the method comprises the steps: transmitting a plurality of groups of first ultrasonic waves to a target tissue, and receiving ultrasonic echoes returned from the target tissue, so as to obtain a plurality of groups of first echo signals; the multiple sets of first echo signals are input into a trained neural network to obtain multiple sets of second echo signals, each set of first echo signals corresponds to one set of second echo signals, and the signal density of each set of second echo signals is higher than that of the corresponding set of first echo signals, the neural network is obtained through training by taking a first data set as an input data set and taking a second data set as a target data set, the first data set comprises a third echo signal, the second data set comprises a fourth echo signal, and the signal density of the fourth echo signal is higher than that of the third echo signal; and generating a multi-frame ultrasonic image according to the multiple groups of second echo signals. According to the method, the quality of the ultrasonic image can be improved while the ultrasonic imaging frame rate is not reduced.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic imaging technology, and more particularly to an ultrasonic imaging method and an ultrasonic imaging system. Background Art

[0002] Ultrasonic imaging is a medical imaging method that uses ultrasonic waves as an information carrier to detect, display, and diagnose human tissues and organs. Ultrasonic imaging is often used to determine the position, size, and shape of organs, determine the scope and physical properties of lesions, provide anatomical diagrams of some glands, and distinguish normal from abnormal fetuses, etc., and has a very wide range of applications in ophthalmology, obstetrics and gynecology, as well as the cardiovascular system, digestive system, urinary system, etc.

[0003] The quality of ultrasonic images is crucial for doctors' diagnosis. On the premise of ensuring the quality of ultrasonic images, the temporal resolution of ultrasonic images has become an increasingly important issue to consider. Improving the temporal resolution of ultrasonic images is particularly important in imaging tissues with obvious movement such as cardiac ultrasound. Since the heart is a beating tissue that beats about 60 times per second, if the frame rate is too low, phenomena such as motion artifacts in its images will be very obvious. That is to say, to obtain the structural information of the heart, a high frame rate is an inevitable requirement.

[0004] Currently, in cardiac ultrasound, the temporal resolution is mainly improved by sacrificing a certain image quality and reducing the number of transmissions. Obviously, the cost of this sacrifice is huge. Therefore, how to achieve high-image-quality imaging without sacrificing the temporal resolution has become an urgent problem to be solved. Summary of the Invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further detailed in the Detailed Description section. The Summary of the Invention section of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0006] An embodiment of the present invention provides an ultrasonic imaging method, and the method includes:

[0007] Transmitting multiple groups of first ultrasonic waves to a target tissue, receiving ultrasonic echoes returned from the target tissue to obtain multiple groups of first echo signals, and each group of the first echo signals corresponds to a frame of ultrasonic image;

[0008] Input multiple sets of the first echo signals into a trained neural network to obtain multiple sets of second echo signals, where each set of the first echo signals corresponds to a set of the second echo signals, and the signal density of each set of the second echo signals in the multiple sets of the second echo signals is higher than the signal density of the corresponding set of the first echo signals in the multiple sets of the first echo signals. Each set of the second echo signals corresponds to a frame of ultrasonic image.

[0009] Among them, the neural network is trained with the first data set as the input data set and the second data set as the target data set. The first data set contains third echo signals, and the second data set contains fourth echo signals. The signal density of the fourth echo signals is higher than the signal density of the third echo signals. Each set of the third echo signals and each set of the fourth echo signals respectively correspond to a frame of ultrasonic image.

[0010] Generate multiple frames of ultrasonic images according to the multiple sets of the second echo signals.

[0011] In one embodiment, the number of transmission positions of the first echo signals is less than the number of transmission positions specified by the Nyquist spatial sampling law.

[0012] The equivalent number of transmission positions of the second echo signals is greater than the number of transmission positions specified by the Nyquist spatial sampling law.

[0013] The number of transmission positions of the third echo signals is less than the number of transmission positions specified by the Nyquist spatial sampling law.

[0014] The number of transmission positions of the fourth echo signals is greater than the number of transmission positions specified by the Nyquist spatial sampling law.

[0015] In one embodiment, the receiving line density of the first echo signals is less than the receiving line density specified by the Nyquist spatial sampling law.

[0016] The equivalent receiving line density of the second echo signals is greater than the receiving line density specified by the Nyquist spatial sampling law.

[0017] The receiving line density of the third echo signals is less than the receiving line density specified by the Nyquist spatial sampling law.

[0018] The receiving line density of the fourth echo signals is greater than the receiving line density specified by the Nyquist spatial sampling law.

[0019] In one embodiment, the first echo signals, the second echo signals, the third echo signals and the fourth echo signals are fan-shaped scanning signals.

[0020] In the first echo signals and the third echo signals, the near-field signal density is higher than the far-field signal density.

[0021] The far-field signal density of the second echo signal is higher than that of the first echo signal, and the far-field signal density of the fourth echo signal is higher than that of the third echo signal.

[0022] In one embodiment, the steps of constructing the first data set and the second data set include:

[0023] Transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the fourth echo signal;

[0024] Extract the echo signals corresponding to some emission lines from the fourth echo signal to obtain the third echo signal.

[0025] In one embodiment, the steps of constructing the first data set and the second data set include:

[0026] Transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the fourth echo signal;

[0027] Interpolate the fourth echo signal to obtain the third echo signal;

[0028] Alternatively, transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the third echo signal;

[0029] Interpolate the third echo signal to obtain the fourth echo signal.

[0030] In one embodiment, the steps of constructing the first data set and the second data set include:

[0031] Transmit a second ultrasonic wave to the target tissue;

[0032] Receive the ultrasonic echo returned from the target tissue, perform beamforming with different receiving line densities to obtain the third echo signal and the fourth echo signal, and the receiving line density corresponding to the fourth echo signal is higher than that corresponding to the third echo signal.

[0033] In one embodiment, the first echo signal, the second echo signal, the third echo signal, and the fourth echo signal are radio frequency signals;

[0034] Alternatively, the first echo signal, the second echo signal, the third echo signal, and the fourth echo signal are baseband signals.

[0035] In one embodiment, the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal; the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal.

[0036] Another aspect of the embodiments of the present invention provides an ultrasonic imaging method, the method comprising:

[0037] Transmitting multiple groups of first ultrasonic waves to a target tissue, and receiving ultrasonic echoes returned from the target tissue to obtain multiple groups of first echo signals;

[0038] Generating multiple frames of first ultrasonic image data according to the multiple groups of first echo signals;

[0039] Inputting the multiple frames of first ultrasonic image data into a trained neural network to obtain multiple frames of second ultrasonic image data, wherein each frame of first ultrasonic image data corresponds to one frame of second ultrasonic image data, and the image quality of each frame of the second ultrasonic image data in the multiple frames of second ultrasonic image data is higher than the image quality of the corresponding frame of the first ultrasonic image data in the multiple frames of first ultrasonic image data.

[0040] Wherein, the neural network is trained with a first data set as an input data set and a second data set as a target data set. The first data set contains third ultrasonic image data, the second data set contains fourth ultrasonic image data, the third ultrasonic image data is generated according to a third echo signal, the fourth ultrasonic image data is generated according to a fourth echo signal, and the signal density of the fourth echo signal is higher than the signal density of the third echo signal.

[0041] Outputting the multiple frames of second ultrasonic image data.

[0042] In one embodiment, the number of transmission positions of the first echo signal is less than the number of transmission positions specified by the Nyquist spatial sampling law;

[0043] The number of transmission positions of the third echo signal is less than the number of transmission positions specified by the Nyquist spatial sampling law;

[0044] The number of transmission positions of the fourth echo signal is greater than the number of transmission positions specified by the Nyquist spatial sampling law.

[0045] In one embodiment, the receiving line density of the first echo signal is less than the receiving line density specified by the Nyquist spatial sampling law;

[0046] The receiving line density of the third echo signal is less than the receiving line density specified by the Nyquist spatial sampling law;

[0047] The receiving line density of the fourth echo signal is greater than the receiving line density specified by the Nyquist spatial sampling law.

[0048] In one embodiment, the first echo signal, the third echo signal, and the fourth echo signal are fan-shaped scan signals;

[0049] In the first echo signal and the third echo signal, the near-field signal density is higher than the far-field signal density;

[0050] The far-field signal density of the fourth echo signal is higher than that of the third echo signal.

[0051] In one embodiment, the steps of constructing the first data set and the second data set include:

[0052] Transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the fourth echo signal;

[0053] Extract the echo signals corresponding to some emission lines from the fourth echo signal to obtain the third echo signal;

[0054] Generate third ultrasonic image data according to the third echo signal, and generate the fourth ultrasonic image data according to the fourth echo signal.

[0055] In one embodiment, the steps of constructing the first data set and the second data set include:

[0056] Transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the fourth echo signal;

[0057] Interpolate the fourth echo signal to obtain the third echo signal;

[0058] Alternatively, transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the third echo signal;

[0059] Interpolate the third echo signal to obtain the fourth echo signal;

[0060] Generate third ultrasonic image data according to the third echo signal, and generate the fourth ultrasonic image data according to the fourth echo signal.

[0061] In one embodiment, the steps of constructing the first data set and the second data set include:

[0062] Transmit a second ultrasonic wave to the target tissue;

[0063] Receive the ultrasonic echoes returned from the target tissue, perform beamforming with different receive line densities to obtain the third echo signal and the fourth echo signal, where the receive line density corresponding to the fourth echo signal is higher than that corresponding to the third echo signal;

[0064] Generate third ultrasonic image data based on the third echo signal, and generate the fourth ultrasonic image data based on the fourth echo signal.

[0065] In one embodiment, the first echo signal, the second echo signal, the third echo signal, and the fourth echo signal are data after beamforming, data after envelope detection, or data after logarithmic compression.

[0066] In one embodiment, the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal; the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal.

[0067] Another aspect of the embodiments of the present invention provides an ultrasonic imaging system, including:

[0068] An ultrasonic probe;

[0069] A transmitting circuit for exciting the ultrasonic probe to transmit ultrasonic waves to the target tissue;

[0070] A receiving circuit for controlling the ultrasonic probe to receive the echo signal of the ultrasonic waves;

[0071] A processor for executing the ultrasonic imaging method as described above to generate an ultrasonic image;

[0072] A display for displaying the ultrasonic image.

[0073] The ultrasonic imaging method and the ultrasonic imaging system according to the embodiments of the present invention use a neural network to convert the first echo signal into a second echo signal with a higher signal density, which can improve the quality of the ultrasonic image while avoiding reducing the frame rate of the ultrasonic image. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] By describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more obvious. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0075] Figure 1 Shows a structural block diagram of an ultrasonic imaging system according to an embodiment of the present invention;

[0076] Figure 2 Schematic flowchart showing an ultrasonic imaging method according to an embodiment of the present invention;

[0077] Figure 3 Schematic diagram showing transmission lines and reception lines according to an embodiment of the present invention;

[0078] Figure 4 Schematic principle diagram showing an ultrasonic imaging method according to an embodiment of the present invention;

[0079] Figure 5 Schematic diagram showing a first echo signal and a second echo signal according to an embodiment of the present invention;

[0080] Figure 6 Schematic flowchart showing an ultrasonic imaging method according to another embodiment of the present invention. Detailed implementation manners

[0081] In order to make the objectives, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0082] In the following description, numerous specific details are given to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known to those skilled in the art are not described.

[0083] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0084] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the related listed items.

[0085] To thoroughly understand the present invention, detailed structures will be presented in the following description to illustrate the technical solutions proposed by the present invention. The alternative embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other embodiments.

[0086] Next, first refer to Figure 1 Describe an ultrasonic imaging system according to an embodiment of the present invention. Figure 1 FIG. 100 shows a schematic structural block diagram of an ultrasonic imaging system 100 according to an embodiment of the present invention.

[0087] As Figure 1 shown, the ultrasonic imaging system 100 includes an ultrasonic probe 110, a transmitting circuit 112, a receiving circuit 114, a processor 116, and a display 118. Further, the ultrasonic imaging system may further include a transmit / receive selection switch 120 and a beam synthesis module 122. The transmitting circuit 112 and the receiving circuit 114 may be connected to the ultrasonic probe 110 through the transmit / receive selection switch 120.

[0088] The ultrasonic probe 110 includes a plurality of transducer array elements. The plurality of transducer array elements may be arranged in a row to form a linear array, or arranged in a two-dimensional matrix to form a planar array. The plurality of transducer array elements may also form a convex array. The transducer array elements are used to emit ultrasonic waves according to the excitation electrical signal, or convert the received ultrasonic waves into electrical signals. Therefore, each transducer array element can be used to realize the mutual conversion between the electrical pulse signal and the ultrasonic wave, so as to emit ultrasonic waves to the tissue in the target area of the object to be measured, and can also be used to receive the ultrasonic wave echo reflected by the tissue.

[0089] During ultrasonic imaging, it is possible to control which transducer array elements are used to emit ultrasonic waves and which transducer array elements are used to receive ultrasonic waves through the transmit sequence and the receive sequence, or control the transducer array elements to be used for emitting ultrasonic waves or receiving the echoes of ultrasonic waves in time slots. The transducer array elements participating in the ultrasonic wave emission can be simultaneously excited by electrical signals to simultaneously emit ultrasonic waves; or, the transducer array elements participating in the ultrasonic beam emission can also be excited by a plurality of electrical signals with a certain time interval to continuously emit ultrasonic waves with a certain time interval.

[0090] During the ultrasonic imaging process, the transmitting circuit 112 generates a transmission sequence according to the control of the processor 116. The transmission sequence is used to control some or all of the multiple transducer elements to emit ultrasonic waves towards the target tissue. The transmission sequence parameters include the number of transducer element positions for transmission and the ultrasonic beam transmission parameters, such as amplitude, frequency, number of transmissions, transmission interval, transmission angle, waveform, focusing position, etc. In some cases, the transmitting circuit 112 is also used to perform phase delay on the transmitted beam, so that different transducer elements emit ultrasonic waves at different times, so that each transmitted ultrasonic beam can be focused in a predetermined region of interest. The transmission sequence parameters corresponding to different imaging modes may be different. After the echo signal is received by the receiving circuit 114 and processed by subsequent modules and corresponding algorithms, ultrasonic images of different imaging modes can be generated.

[0091] The receiving circuit 114 may include one or more amplifiers, analog-to-digital converters, etc. The amplifier is used to amplify the received echo signal after appropriate gain compensation, and the analog-to-digital converter is used to sample the analog echo signal at a predetermined time interval, so as to convert it into a digital signal. The digitized echo signal still retains amplitude information, frequency information, and phase information. The receiving circuit 114 sends the echo signal to the beam synthesis module 122 for processing.

[0092] The beam synthesis module 122 performs processing such as focusing delay, weighting, and channel summation on the echo signal, and then sends it to the processor 116. The processor 116 performs processing such as signal detection, signal enhancement, data conversion, and logarithmic compression on the echo signal to form an ultrasonic image. The ultrasonic image obtained by the processor 116 can be displayed on the display 118 or stored in the memory 124.

[0093] Optionally, the processor 116 can be implemented as software, hardware, firmware, or any combination thereof, and can use one or more application specific integrated circuits (ASICs), one or more general integrated circuits, one or more microprocessors, one or more programmable logic devices, or any combination of the foregoing circuits and / or devices, or other suitable circuits or devices. And, the processor 116 can control other components in the ultrasonic imaging system 100 to perform the corresponding steps of the methods in the various embodiments of this specification.

[0094] The display 118 is connected to the processor 116. The display 118 can be a touch display screen, a liquid crystal display screen, etc.; or, the display 118 can be an independent display such as a liquid crystal display or a television outside the ultrasonic imaging system 100; or, the display 118 can be the display screen of an electronic device such as a smart phone or a tablet computer, etc. Among them, the number of displays 118 can be one or more.

[0095] The display 118 can display the ultrasonic image obtained by the processor 116. In addition, while displaying the ultrasonic image, the display 118 can also provide a graphical interface for the user to perform human-computer interaction. One or more controlled objects are set on the graphical interface, and the user is provided with a human-computer interaction device to input operation instructions to control these controlled objects, so as to execute corresponding control operations. For example, an icon is displayed on the graphical interface, and the icon can be operated by using the human-computer interaction device to perform a specific function, such as drawing a region of interest box on the ultrasonic image, etc.

[0096] Optionally, the ultrasonic imaging system 100 can further include other human-computer interaction devices outside the display 118, which are connected to the processor 116. For example, the processor 116 can be connected to the human-computer interaction device through an external input / output port. The external input / output port can be a wireless communication module, a wired communication module, or a combination of both. The external input / output port can also be implemented based on USB, bus protocols such as CAN, and / or wired network protocols, etc.

[0097] Among them, the human-computer interaction device can include an input device for detecting the input information of the user. The input information can be, for example, a control instruction for the ultrasonic emission / reception timing, an operation input instruction for drawing points, lines, or boxes on the ultrasonic image, or can also include other instruction types. The input device can include one or a combination of multiple of a keyboard, a mouse, a roller, a trackball, a mobile input device (such as a mobile device with a touch display screen, a mobile phone, etc.), a multi-functional knob, etc. The human-computer interaction device can also include an output device such as a printer.

[0098] The ultrasonic imaging system 100 can also include a memory 124 for storing instructions executed by the processor, storing received ultrasonic echoes, storing ultrasonic images, etc. The memory can be a flash memory card, a solid-state memory, a hard disk, etc. It can be a volatile memory and / or a non-volatile memory, a removable memory and / or a non-removable memory, etc.

[0099] It should be understood that Figure 1 The components included in the illustrated ultrasonic imaging system 100 are only illustrative, and it can include more or fewer components. The present invention is not limited thereto.

[0100] Next, reference will be made to Figure 2 describe an ultrasonic imaging method according to an embodiment of the present invention. Figure 2 FIG. 4 is a schematic flowchart of an ultrasonic imaging method 200 according to an embodiment of the present invention.

[0101] As Figure 2 shown, an ultrasonic imaging method 200 according to an embodiment of the present invention includes the following steps:

[0102] In step S210, multiple groups of first ultrasonic waves are emitted to a target tissue, and ultrasonic echoes returned from the target tissue are received to obtain multiple groups of first echo signals, and each group of the first echo signals corresponds to a frame of ultrasonic image;

[0103] In step S220, the multiple groups of first echo signals are input into a trained neural network to obtain multiple groups of second echo signals, where each group of first echo signals corresponds to a group of second echo signals, and the signal density of each group of the second echo signals in the multiple groups of second echo signals is higher than the signal density of the corresponding group of first echo signals in the multiple groups of first echo signals, and each group of the second echo signals corresponds to a frame of ultrasonic image,

[0104] wherein, the neural network is trained with a first data set as an input data set and a second data set as a target data set, the first data set contains third echo signals, the second data set contains fourth echo signals, the signal density of the fourth echo signals is higher than the signal density of the third echo signals, and each group of the third echo signals and each group of the fourth echo signals respectively correspond to a frame of ultrasonic image;

[0105] In step S230, multiple frames of ultrasonic images are generated according to the multiple groups of second echo signals.

[0106] The ultrasonic imaging method 200 according to an embodiment of the present invention uses a neural network to convert the first echo signals into second echo signals with higher signal density, which can improve the quality of ultrasonic images while avoiding reducing the frame rate of ultrasonic images.

[0107] Specifically, in step S210, multiple groups of first ultrasonic waves are emitted to a target tissue, and first echo signals returned from the target tissue are received. Refer to Figure 1In an ultrasonic imaging system, a transmission circuit generates a transmission waveform, which is applied to one or more array elements in an ultrasonic probe to form a transmission beam. A transmit / receive selection switch controls the array elements to switch between transmission and reception. After transmission is completed, it is switched to the reception state. After the ultrasonic wave propagates to the imaging region and is scattered by the target tissue, at the same time, the array elements are switched to the reception state and receive the echo returned by the target tissue, and front-end processing such as signal amplification, analog-to-digital conversion, and receive coherent synthesis is performed on it. As the transmission lines and reception lines change, the above processing is repeated multiple times to obtain a set of first echo signals, and each set of first echo signals corresponds to one frame of ultrasonic image, which can specifically correspond to the whole or a part of one frame of ultrasonic image. The target tissue includes but is not limited to the heart.

[0108] The ultrasonic imaging method according to the embodiments of the present invention can be used for tissue imaging, and can also be applied to Doppler imaging mode and other imaging modes; it can be applied to conventional two-dimensional ultrasonic imaging, and can also be applied to three-dimensional ultrasonic imaging.

[0109] Exemplarily, the first echo signal can be an RF (radio frequency) signal or an IQ signal (i.e., a baseband signal). Among them, the RF signal is the echo signal before quadrature demodulation, and the IQ signal is the echo signal after quadrature demodulation. After quadrature demodulation, the echo signal is divided into two mutually orthogonal I and Q signals, where I and Q represent in-phase and quadrature respectively, and the two signals mainly retain the low-frequency part of the original signal.

[0110] Usually, when performing ultrasonic imaging of positions such as the heart, it is necessary to balance image quality and resolution. However, since the embodiments of the present invention will subsequently improve the signal density through a neural network and thus improve the image quality, therefore, an imaging method with a high frame rate and a low signal density can be adopted to obtain the first echo signal. Among them, methods such as reducing the number of transmission positions, reducing the reception line density, and reducing the transmission line density can be used to improve the imaging frame rate.

[0111] Specifically, the ultrasonic imaging system performs imaging by transmitting ultrasonic signals at different transmission line positions and receiving signals at the reception line positions, as Figure 3 shown. The number of reception lines is called the reception line density, and the number of transmission lines is called the transmission line density. The more transmission lines, the more information is obtained, and the better the quality of the corresponding ultrasonic image, but the longer the time required. In addition, the higher the reception line density, the greater the amount of calculation required, and the higher the requirement for hardware. Therefore, reducing the number of transmission positions, reception line density, transmission line density, etc. can improve the frame rate.

[0112] Exemplarily, reducing the number of emission positions and the receiving line density includes: making the number of emission positions of the first echo signal less than the number of emission positions specified by the Nyquist spatial sampling law, and / or making the receiving line density of the first echo signal less than the receiving line density specified by the Nyquist spatial sampling law.

[0113] Among them, the Nyquist spatial sampling law describes the minimum sampling frequency required for sampling a continuous signal in the spatial domain. The core idea of the Nyquist spatial sampling law is that the spectrum of the signal is limited. If sampling is performed at a sampling frequency lower than twice its highest frequency, aliasing will occur, resulting in the signal being unable to be accurately reconstructed. Therefore, for an image, in order to avoid aliasing and meet the resolution requirements, it is necessary to satisfy the repetition pitch 1 / x > 2fx, where x is the point pitch, that is, the receiving line pitch, and (-fx, fx) is the lateral frequency range of the image. It can be seen that usually during ultrasonic imaging, the number of emission positions needs to be greater than the number of emission positions specified by the Nyquist spatial sampling law, and the receiving line density needs to be greater than the receiving line density specified by the Nyquist spatial sampling law; while in the embodiments of the present invention, since the signal density will be increased by a neural network later, it is not necessary to meet the above requirements.

[0114] In step S220, as Figure 4 shown, input multiple groups of first echo signals into the trained neural network to obtain multiple groups of second echo signals, where each group of first echo signals corresponds to a group of second echo signals, the signal density of each group of second echo signals is higher than the signal density of the corresponding group of first echo signals, and each group of second echo signals corresponds to a frame of ultrasonic image.

[0115] The neural network of the embodiments of the present invention is used to increase the signal density of the first echo signal, thereby improving the image quality of the ultrasonic image data. The ultrasonic imaging system obtains multiple groups of first echo signals by using imaging parameters of high frame rate and low density. Although its imaging frame rate is high, the low signal density results in low image quality and cannot meet the requirements for spatial resolution. After increasing the signal density through the neural network, the finally obtained ultrasonic image data sequence has both a high frame rate and high image quality. Moreover, compared with increasing the signal density by means such as interpolation, using a neural network to increase the signal density has a faster operation speed and stronger real-time performance.

[0116] The neural network of the embodiment of the present invention is trained with the first data set as the input data set and the second data set as the target data set. Among them, the first data set contains multiple groups of third echo signals, and the second data set contains multiple groups of fourth echo signals. Each group of third echo signals and each group of fourth echo signals respectively correspond to a frame of ultrasonic image. Each group of third echo signals corresponds to a group of fourth echo signals, and the signal density of each group of fourth echo signals is higher than that of the group of third echo signals corresponding thereto. The third echo signal and the fourth echo signal are signals in the signal domain, which may specifically be radio frequency signals or baseband signals. By selecting a suitable neural network architecture and through continuous iteration, after the third echo signals in the first data set are input into the neural network, the data output by the neural network continuously approaches the corresponding fourth echo signals in the second data set. When the error is less than the set value, the training is completed. The finally trained neural network can convert multiple groups of first echo signals into second echo signals with higher signal density after obtaining them, thereby improving the image quality without reducing the frame rate. Exemplarily, the neural network includes, but is not limited to, convolutional neural network, recurrent neural network, adversarial neural network, and attention neural network, etc.

[0117] Exemplarily, the signal density of the fourth echo signal being higher than that of the third echo signal may include that the number of emission positions of the third echo signal is less than the number of emission positions specified by the Nyquist spatial sampling law, while the number of emission positions of the fourth echo signal is greater than the number of emission positions specified by the Nyquist spatial sampling law; or the receiving line density of the third echo signal is less than the receiving line density specified by the Nyquist spatial sampling law, while the receiving line density of the fourth echo signal is greater than the receiving line density specified by the Nyquist spatial sampling law. Thus, after training the neural network with the third echo signal and the fourth echo signal, after inputting the first echo signal with the number of emission positions less than the number of emission positions specified by the Nyquist spatial sampling law into the neural network, a second echo signal with the number of equivalent emission positions greater than the number of emission positions specified by the Nyquist spatial sampling law can be obtained; or, after inputting the first echo signal with the receiving line density less than the receiving line density specified by the Nyquist spatial sampling law into the neural network, a second echo signal with the receiving line density greater than the receiving line density specified by the Nyquist spatial sampling law can be obtained.

[0118] In some embodiments, the first echo signal, the second echo signal, the third echo signal, and the fourth echo signal are fan-shaped scan signals, that is, echo signals obtained by fan-shaped scan probes such as convex array and phased array. In the first echo signal and the third echo signal, the signal density of the near field is higher than that of the far field; the signal density of the far field of the second echo signal is higher than that of the far field of the first echo signal, and the signal density of the far field of the fourth echo signal is higher than that of the far field of the third echo signal. As Figure 5As shown, due to the different line densities per unit radian in the near field and the far field, the line density in the near field is higher than that in the far field for the fan-shaped scan signal, resulting in possible redundancy in the near field and insufficient lateral resolution in the far field. However, the far-field signal density of the fourth echo signal is higher than that of the third echo signal, so the above problems do not exist. The neural network trained based on the third echo signal and the fourth echo signal can also increase the far-field signal density of the second echo signal and solve the problem of insufficient lateral resolution in the near field and the far field in the first echo signal.

[0119] Exemplarily, the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal, and the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal. When the third echo signal and the fourth echo signal are signals collected by an ultrasonic imaging system, imaging methods with low signal density and high signal density can be respectively used for the same target tissue to obtain the third echo signal and the fourth echo signal. The frame rate of the fourth echo signal may be relatively low, but since it is not used for actual clinical diagnosis, the influence of the frame rate can be ignored. When the third echo signal or the fourth echo signal is a simulation signal, a third echo signal with low signal density and a fourth echo signal with high signal density can be obtained through simulation software.

[0120] In some embodiments, the third echo signal and the fourth echo signal can be obtained by signal extraction. Specifically, first, a second ultrasonic wave is emitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the fourth echo signal. The second ultrasonic wave can have a high emission line density. Then, the echo signals corresponding to some emission lines are extracted from the fourth echo signal to obtain the third echo signal. The third echo signal has a low emission line density, so the signal density of the fourth echo signal is higher than that of the third echo signal.

[0121] In another embodiment, the third echo signal and the fourth echo signal can be obtained by interpolation. Specifically, first, a second ultrasonic wave is emitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the fourth echo signal. The fourth echo signal is interpolated to reduce the signal density to obtain the third echo signal. Alternatively, a second ultrasonic wave is emitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the third echo signal; the third echo signal is interpolated to increase the signal density to obtain the fourth echo signal.

[0122] Alternatively, a second ultrasonic wave can also be emitted towards the target tissue; the ultrasonic echo returned from the target tissue is received, beamforming is performed with different receiving line densities to obtain a third echo signal and a fourth echo signal, wherein the receiving line density used for the fourth echo signal during beamforming is higher than that used for the third echo signal during beamforming, so that the signal density of the fourth echo signal is higher than that of the third echo signal.

[0123] In the above example, since both the third echo signal and the fourth echo signal are generated by emitting the second ultrasonic wave and receiving the echo, they have a high degree of matching. The neural network trained based on the third echo signal and the fourth echo signal can improve the signal density of the first echo signal while ensuring the imaging accuracy.

[0124] Finally, in step S230, multiple frames of ultrasonic images are generated according to multiple groups of second echo signals. Specifically, since the second echo signal is a radio frequency signal or a baseband signal, that is, a signal whose amplitude and phase are both modulated, in order to further obtain the amplitude information of the echo for imaging, envelope detection and logarithmic compression are also required.

[0125] Among them, the purpose of envelope detection is to extract the amplitude information from the radio frequency signal. Exemplarily, the Hilbert transform method can be used for envelope detection. The original signal undergoes the Hilbert transform to obtain the quadrature signal of the original signal. A complex analytic signal is constructed with the original signal as the real part and the quadrature signal obtained by the Hilbert transform as the imaginary part. The modulus of this signal is the envelope of the original signal. Alternatively, envelope detection can also be performed through IQ demodulation. IQ demodulation has frequency selectivity, can select specific frequency components for final imaging, and has strong anti-interference ability.

[0126] For the echo signal after envelope detection, the amplitude envelope line of the echo signal is obtained. Since the value range of the usually obtained envelope line after normalization is between [0, 1], while the display level of the ultrasonic imaging system is generally between [0, 255], the values on this envelope line cannot be directly used for imaging, and the original value range of the envelope line needs to be mapped to the display interval of the ultrasonic imaging system. In order to improve the ultrasonic imaging effect of the reflected echo signal in the non-strong focusing region, the mapping method adopted is logarithmic compression. Finally, coordinate transformation is performed on the data after logarithmic compression to obtain displayable ultrasonic image data, which is output to the display for display.

[0127] The ultrasonic imaging method 200 according to the embodiment of the present invention uses a neural network to convert the first echo signal into a second echo signal with a higher signal density, which can improve the quality of the ultrasonic image while avoiding reducing the frame rate of the ultrasonic image.

[0128] Another aspect of the embodiment of the present invention provides an ultrasonic imaging method, refer toFigure 6 , the ultrasonic imaging method 600 includes the following steps:

[0129] In step S610, multiple groups of first ultrasonic waves are transmitted to the target tissue, and ultrasonic echoes returned from the target tissue are received to obtain multiple groups of first echo signals;

[0130] In step S620, multiple frames of first ultrasonic image data are generated based on the multiple groups of first echo signals;

[0131] In step S630, multiple frames of the first ultrasonic image data are input into a trained neural network to obtain multiple frames of second ultrasonic image data, where each frame of the first ultrasonic image data corresponds to one frame of the second ultrasonic image data, and the image quality of each frame of the second ultrasonic image data in the multiple frames of the second ultrasonic image data is higher than the image quality of the corresponding frame of the first ultrasonic image data in the multiple frames of the first ultrasonic image data.

[0132] Wherein, the neural network is trained with a first data set as the input data set and a second data set as the target data set. The first data set contains third ultrasonic image data, and the second data set contains fourth ultrasonic image data. The third ultrasonic image data is generated based on third echo signals, and the fourth ultrasonic image data is generated based on fourth echo signals. The signal density of the fourth echo signals is higher than the signal density of the third echo signals.

[0133] In step S640, the multiple frames of the second ultrasonic image data are output.

[0134] The ultrasonic imaging method 600 according to the embodiment of the present invention is similar to the ultrasonic imaging method 200 described above. It also uses a high frame rate and low signal density method for ultrasonic imaging to ensure the frame rate of the ultrasonic image and improve the quality of the ultrasonic image through a neural network. The difference is that the neural network in this embodiment acts on the first ultrasonic image data in the image domain, and at least one frame of second ultrasonic image data is added between every two adjacent frames of the first ultrasonic image data. The data in the image domain can be data after beam synthesis, data after envelope detection, or data after logarithmic compression, etc. In comparison, the first echo signal or the second echo signal can be an RF (radio frequency) signal or an IQ signal (i.e., a baseband signal). The RF signal is the echo signal before quadrature demodulation, and the IQ signal is the echo signal after quadrature demodulation.

[0135] Since the neural network in this embodiment acts on the image domain, the first dataset for training the neural network contains multiple frames of third ultrasonic image data, and the second dataset contains multiple frames of fourth ultrasonic image data. The third ultrasonic image data and the fourth ultrasonic image data can also be the data after envelope detection or the data after logarithmic compression. Among them, the third ultrasonic image data corresponds to the fourth image data one by one. The third ultrasonic image data is generated according to the third echo signal, and the fourth ultrasonic image data is generated according to the fourth echo signal. The signal density of the fourth echo signal is higher than that of the third echo signal.

[0136] Exemplarily, the number of transmission positions of the third echo signal is less than the number of transmission positions specified by the Nyquist spatial sampling law, and the number of transmission positions of the fourth echo signal is greater than the number of transmission positions specified by the Nyquist spatial sampling law. Therefore, the trained neural network can convert the first ultrasonic image data into the second ultrasonic image data, where the number of transmission positions of the first echo signal used to generate the first ultrasonic image data is less than the number of transmission positions specified by the Nyquist spatial sampling law, while the equivalent number of transmission positions of the second ultrasonic image data is greater than the number of transmission positions specified by the Nyquist spatial sampling law.

[0137] And / or, the receiving line density of the third echo signal is less than the receiving line density specified by the Nyquist spatial sampling law, and the receiving line density of the fourth echo signal is greater than the receiving line density specified by the Nyquist spatial sampling law. Therefore, the trained neural network can convert the first ultrasonic image data into the second ultrasonic image data, where the receiving line density of the first echo signal used to generate the first ultrasonic image data is less than the receiving line density specified by the Nyquist spatial sampling law, while the equivalent receiving line density of the second ultrasonic image data is greater than the receiving line density specified by the Nyquist spatial sampling law.

[0138] In some embodiments, the first echo signal, the third echo signal, and the fourth echo signal are fan-shaped scanning signals; in the first echo signal and the third echo signal, the near-field signal density is higher than the far-field signal density, while the far-field signal density of the fourth echo signal is higher than the far-field signal density of the third echo signal. Due to the different line densities per unit radian in the near field and the far field of the fan-shaped scanning signal, the near-field line density is higher than the far-field line density, resulting in possible redundancy in the near field and insufficient lateral resolution in the far field. However, since the far-field signal density of the fourth echo signal is higher than the far-field signal density of the third echo signal, the above problems do not exist. The neural network trained based on the third ultrasonic image data and the fourth ultrasonic image data can also solve the problem of insufficient lateral resolution in the near field and the far field in the first echo signal.

[0139] Exemplarily, the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal; the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal.

[0140] In some embodiments, the third echo signal and the fourth echo signal can be obtained by signal extraction. Specifically, first, a second ultrasonic wave is transmitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the fourth echo signal. The second ultrasonic wave can have a high transmission line density. Then, the echo signals corresponding to some transmission lines are extracted from the fourth echo signal to obtain the third echo signal. The third echo signal has a low transmission line density. Therefore, the signal density of the fourth echo signal is higher than that of the third echo signal. Finally, third ultrasonic image data is generated based on the third echo signal, and fourth ultrasonic image data is generated based on the fourth echo signal.

[0141] In another embodiment, the third echo signal and the fourth echo signal can be obtained by interpolation. Specifically, first, a second ultrasonic wave is transmitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the fourth echo signal. The fourth echo signal is interpolated to reduce the signal density to obtain the third echo signal. Alternatively, a second ultrasonic wave is transmitted to the target tissue, and the ultrasonic echo returned from the target tissue is received to obtain the third echo signal; the third echo signal is interpolated to increase the signal density to obtain the fourth echo signal. Finally, third ultrasonic image data is generated based on the third echo signal, and fourth ultrasonic image data is generated based on the fourth echo signal.

[0142] Alternatively, a second ultrasonic wave can also be transmitted to the target tissue; the ultrasonic echo returned from the target tissue is received, and beamforming is performed with different receiving line densities to obtain the third echo signal and the fourth echo signal, where the receiving line density used for beamforming of the fourth echo signal is higher than that used for beamforming of the third echo signal, so that the signal density of the fourth echo signal is higher than that of the third echo signal. Finally, third ultrasonic image data is generated based on the third echo signal, and fourth ultrasonic image data is generated based on the fourth echo signal.

[0143] In the above examples, since both the third echo signal and the fourth echo signal are generated by transmitting the second ultrasonic wave and receiving the echo, there is a high degree of matching between them. The neural network trained based on the third ultrasonic image data and the fourth ultrasonic image data can improve the image quality of the first ultrasonic image while ensuring the imaging accuracy.

[0144] The ultrasonic imaging method 600 according to the embodiments of the present invention collects multiple frames of first ultrasonic image data in a high frame rate and low signal density manner, and inputs the actually collected multiple frames of first ultrasonic image data into the neural network. The neural network converts it into second ultrasonic image data with a higher signal density, which can improve the ultrasonic image quality while avoiding reducing the frame rate of the ultrasonic image.

[0145] An embodiment of the present invention further provides an ultrasonic imaging system for implementing the above ultrasonic imaging method 200 or ultrasonic imaging method 600. Now referring back to Figure 1 , the ultrasonic imaging system can be implemented as the ultrasonic imaging system 100 shown in Figure 1 . The ultrasonic imaging system 100 may include an ultrasonic probe 110, a transmitting circuit 112, a receiving circuit 114, a processor 116, and a display 118. Optionally, the ultrasonic imaging system 100 may further include a transmit / receive selection switch 120 and a beamforming module 122. The transmitting circuit 112 and the receiving circuit 114 can be connected to the ultrasonic probe 110 through the transmit / receive selection switch 120. Descriptions of the relevant components can refer to the relevant descriptions above and will not be elaborated here.

[0146] Among them, the transmitting circuit 112 is used to excite the ultrasonic probe 110 to emit ultrasonic waves to the target tissue; the receiving circuit 114 is used to control the ultrasonic probe 110 to receive the echo of the ultrasonic wave to obtain an echo signal; the processor 116 is used to execute the steps of the above ultrasonic imaging method 200 or ultrasonic imaging method 400. The processor 116 is also used to control the display 118 to display an ultrasonic image.

[0147] Only the main functions of the components of the ultrasonic imaging system are described above. For more details, refer to the relevant descriptions of the ultrasonic imaging method 200 and the ultrasonic imaging method 600. The ultrasonic imaging system according to the embodiment of the present invention collects multiple groups of first echo signals or multiple frames of first ultrasonic image data in a high frame rate and low signal density manner, and inputs the actually collected multiple groups of first echo signals or first ultrasonic image data into a neural network, and improves its signal density through the neural network, which can improve the quality of the ultrasonic image while avoiding reducing the frame rate of the ultrasonic image.

[0148] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as claimed in the appended claims.

[0149] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0150] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0151] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0152] Similarly, it should be understood that, in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be construed as reflecting the intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the inventive point lies in that the corresponding technical problems can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present invention.

[0153] Those skilled in the art can understand that, except for features that are mutually exclusive, any combination can be used for all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

[0154] In addition, those skilled in the art can understand that, although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments means that it is within the scope of the present invention and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0155] Each component embodiment of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some modules according to the embodiments of the present invention. The present invention can also be implemented as a device program (for example, a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0156] It should be noted that the above embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0157] As described above, it is only the specific implementation manner of the present invention or the description of the specific implementation manner. The protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all of them should be covered by the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An ultrasonic imaging method, characterized in that, the method includes: Transmitting multiple groups of first ultrasonic waves to a target tissue, and receiving ultrasonic echoes returned from the target tissue to obtain multiple groups of first echo signals, where each group of the first echo signals corresponds to a frame of ultrasonic image; Inputting the multiple groups of the first echo signals into a trained neural network to obtain multiple groups of second echo signals, where each group of the first echo signals corresponds to a group of the second echo signals, and the signal density of each group of the second echo signals in the multiple groups of second echo signals is higher than the signal density of the corresponding group of the first echo signals in the multiple groups of first echo signals, and each group of the second echo signals corresponds to a frame of ultrasonic image, wherein, the neural network is trained with a first data set as the input data set and a second data set as the target data set. The first data set contains third echo signals, the second data set contains fourth echo signals, the signal density of the fourth echo signals is higher than the signal density of the third echo signals, and each group of the third echo signals and each group of the fourth echo signals respectively correspond to a frame of ultrasonic image; Generating multiple frames of ultrasonic images according to the multiple groups of second echo signals.

2. The ultrasonic imaging method according to claim 1, characterized in that, the number of emission positions of the first echo signals is less than the number of emission positions specified by the Nyquist spatial sampling law; the equivalent number of emission positions of the second echo signals is greater than the number of emission positions specified by the Nyquist spatial sampling law; the number of emission positions of the third echo signals is less than the number of emission positions specified by the Nyquist spatial sampling law; the number of emission positions of the fourth echo signals is greater than the number of emission positions specified by the Nyquist spatial sampling law.

3. The ultrasonic imaging method according to claim 1 or 2, characterized in that, the receiving line density of the first echo signals is less than the receiving line density specified by the Nyquist spatial sampling law; the equivalent receiving line density of the second echo signals is greater than the receiving line density specified by the Nyquist spatial sampling law; the receiving line density of the third echo signals is less than the receiving line density specified by the Nyquist spatial sampling law; the receiving line density of the fourth echo signals is greater than the receiving line density specified by the Nyquist spatial sampling law.

4. The ultrasonic imaging method according to claim 1, characterized in that, the first echo signals, the second echo signals, the third echo signals and the fourth echo signals are fan-shaped scan signals; in the first echo signals and the third echo signals, the near-field signal density is higher than the far-field signal density; the far-field signal density of the second echo signals is higher than the far-field signal density of the first echo signals, and the far-field signal density of the fourth echo signals is higher than the far-field signal density of the third echo signals.

5. The ultrasonic imaging method according to claim 1, characterized in that, the steps of constructing the first data set and the second data set include: Transmitting second ultrasonic waves to a target tissue, and receiving ultrasonic echoes returned from the target tissue to obtain the fourth echo signals; Extract the echo signals corresponding to some transmit lines from the fourth echo signal to obtain the third echo signal.

6. The ultrasonic imaging method according to claim 1, wherein, the steps of constructing the first data set and the second data set include: transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the fourth echo signal; interpolate the fourth echo signal to obtain the third echo signal; alternatively, transmit a second ultrasonic wave to the target tissue, and receive the ultrasonic echo returned from the target tissue to obtain the third echo signal; interpolate the third echo signal to obtain the fourth echo signal.

7. The ultrasonic imaging method according to claim 1, wherein, the steps of constructing the first data set and the second data set include: transmit a second ultrasonic wave to the target tissue; receive the ultrasonic echo returned from the target tissue, perform beamforming with different receive line densities to obtain the third echo signal and the fourth echo signal, and the receive line density corresponding to the fourth echo signal is higher than the receive line density corresponding to the third echo signal.

8. The ultrasonic imaging method according to claim 1, wherein, the first echo signal, the second echo signal, the third echo signal and the fourth echo signal are RF signals; alternatively, the first echo signal, the second echo signal, the third echo signal and the fourth echo signal are baseband signals.

9. The ultrasonic imaging method according to claim 1, wherein, the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal; the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal.

10. An ultrasonic imaging method, wherein, the method includes: transmit multiple groups of first ultrasonic waves to the target tissue, and receive the ultrasonic echoes returned from the target tissue to obtain multiple groups of first echo signals; generate multiple frames of first ultrasonic image data according to the multiple groups of first echo signals; input the multiple frames of first ultrasonic image data into a trained neural network to obtain multiple frames of second ultrasonic image data, wherein each frame of the first ultrasonic image data corresponds to one frame of the second ultrasonic image data, and the image quality of each frame of the second ultrasonic image data in the multiple frames of second ultrasonic image data is higher than the image quality of the corresponding frame of the first ultrasonic image data in the multiple frames of first ultrasonic image data, wherein, the neural network is trained with the first data set as the input data set and the second data set as the target data set. The first data set contains third ultrasonic image data, and the second data set contains fourth ultrasonic image data. The third ultrasonic image data is generated according to the third echo signal, and the fourth ultrasonic image data is generated according to the fourth echo signal. The signal density of the fourth echo signal is higher than the signal density of the third echo signal; output the multiple frames of second ultrasonic image data.

11. The ultrasonic imaging method according to claim 10, wherein, The number of transmission positions of the first echo signal is less than the number of transmission positions specified by the Nyquist spatial sampling law; The number of transmission positions of the third echo signal is less than the number of transmission positions specified by the Nyquist spatial sampling law; The number of transmission positions of the fourth echo signal is greater than the number of transmission positions specified by the Nyquist spatial sampling law.

12. The ultrasonic imaging method according to claim 10 or 11, characterized in that the receiving line density of the first echo signal is less than the receiving line density specified by the Nyquist spatial sampling law; the receiving line density of the third echo signal is less than the receiving line density specified by the Nyquist spatial sampling law; the receiving line density of the fourth echo signal is greater than the receiving line density specified by the Nyquist spatial sampling law.

13. The ultrasonic imaging method according to claim 10, characterized in that the first echo signal, the third echo signal and the fourth echo signal are fan-shaped scan signals; in the first echo signal and the third echo signal, the near-field signal density is higher than the far-field signal density; the far-field signal density of the fourth echo signal is higher than the far-field signal density of the third echo signal.

14. The ultrasonic imaging method according to claim 10, characterized in that the steps of constructing the first data set and the second data set include: transmitting a second ultrasonic wave to a target tissue and receiving an ultrasonic echo returned from the target tissue to obtain the fourth echo signal; extracting echo signals corresponding to some transmission lines from the fourth echo signal to obtain the third echo signal; generating third ultrasonic image data according to the third echo signal and generating the fourth ultrasonic image data according to the fourth echo signal.

15. The ultrasonic imaging method according to claim 10, characterized in that the steps of constructing the first data set and the second data set include: transmitting a second ultrasonic wave to a target tissue and receiving an ultrasonic echo returned from the target tissue to obtain the fourth echo signal; interpolating the fourth echo signal to obtain the third echo signal; alternatively, transmitting a second ultrasonic wave to a target tissue and receiving an ultrasonic echo returned from the target tissue to obtain the third echo signal; interpolating the third echo signal to obtain the fourth echo signal; generating third ultrasonic image data according to the third echo signal and generating the fourth ultrasonic image data according to the fourth echo signal.

16. The ultrasonic imaging method according to claim 10, characterized in that the steps of constructing the first data set and the second data set include: transmitting a second ultrasonic wave to a target tissue; receiving an ultrasonic echo returned from the target tissue and performing beam synthesis with different receiving line densities to obtain the third echo signal and the fourth echo signal, and the receiving line density corresponding to the fourth echo signal is higher than the receiving line density corresponding to the third echo signal; generating third ultrasonic image data according to the third echo signal and generating the fourth ultrasonic image data according to the fourth echo signal.

17. The ultrasonic imaging method according to claim 10, It is characterized in that the first echo signal, the second echo signal, the third echo signal and the fourth echo signal are data after beam synthesis, data after envelope detection or data after logarithmic compression.

18. The ultrasonic imaging method according to claim 10, It is characterized in that the third echo signal is a signal collected by an ultrasonic imaging system or a simulation signal; the fourth echo signal is a signal collected by an ultrasonic imaging system or a simulation signal.

19. An ultrasonic imaging system, It is characterized in that comprising: an ultrasonic probe; a transmitting circuit for exciting the ultrasonic probe to emit ultrasonic waves towards a target tissue; a receiving circuit for controlling the ultrasonic probe to receive echo signals of the ultrasonic waves; a processor for executing the ultrasonic imaging method according to any one of claims 1-18 to generate an ultrasonic image; a display for displaying the ultrasonic image.

Images