Ultrasonic plane wave harmonic imaging method, medium and electronic equipment

Abstract

The invention provides an ultrasonic plane wave harmonic imaging method, a medium and electronic equipment. The method comprises the following steps: controlling a linear array with # imgabs 0 # array elements to perform transmitting and receiving acquisition, determining # imgabs 1 # angle plane waves for imaging, calculating excitation delay corresponding to each angle plane wave, and obtaining plane wave delay excitation of # imgabs 3 # array elements of a # imgabs 2 # group; repeating each plane wave delay excitation by # imgabs 4 # times to form excitation groups, and arranging the excitation groups to form different emission codes of # imgabs 5 # times; respectively performing positive pulse emission and negative pulse emission by using different emission codes of the generated # imgabs6 # to obtain code emission echo data of a # imgabs8 # channel of a # imgabs7 # group; performing specific harmonic decoding on the coded emission echo data to obtain harmonic echo data emitted by plane waves at # imgabs9 # angles; frequency domain beam forming and signal processing are carried out on the harmonic echo data of the # imgabs 10 # angle plane waves respectively, and a final ultrasonic image is obtained. According to the invention, the signal-to-noise ratio of the harmonic component in the plane wave echo signal can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic imaging, and in particular to an ultrasonic plane wave harmonic imaging method, medium and electronic equipment. Background Art

[0002] Harmonic imaging and plane wave imaging are two important ultrasound imaging techniques.

[0003] Harmonic imaging refers to the technology of using the harmonic components in ultrasound echoes for imaging. Due to the nonlinear characteristics of biological tissues, ultrasound will generate harmonic components when propagating in the human body, and its frequency is an integer multiple of the transmitted ultrasound frequency. Using harmonic components for imaging has many advantages, including improving imaging resolution, suppressing side lobes, eliminating echo wave artifacts, and reducing the thickness of the imaging section.

[0004] Plane wave imaging is a technology that uses plane waves of different inclination angles to perform imaging. The coherent superposition of images of plane waves at multiple angles can achieve pixel-level focusing effects. Compared with the traditional line-by-line focusing scanning mode, which requires hundreds of transmissions to obtain an image, plane waves only require a few to a dozen transmissions to complete an imaging operation, thus achieving an extremely high imaging frame rate.

[0005] Combining harmonic technology with plane wave technology can achieve high frame rate, high resolution, and high contrast at the same time, which is an effective way to achieve high-quality ultrasonic imaging and gain ultrasonic imaging diagnosis.

[0006] However, the nonlinear characteristics of biological tissues are not particularly significant, and the attenuation of ultrasound is frequency-dependent, so the energy of the harmonic components is much lower than that of the fundamental components, resulting in an extremely low signal-to-noise ratio of the harmonic signal and a very limited imaging depth of the harmonic mode. Summary of the invention

[0007] The purpose of the present application is to provide an ultrasonic plane wave harmonic imaging method, medium and electronic equipment, which can at least partially solve the above-mentioned technical problems existing in the prior art.

[0008] One aspect of the present application provides an ultrasonic plane wave harmonic imaging method. The method comprises: controlling a A linear array of transducer elements is used to transmit and receive data to determine the The excitation delay corresponding to each angle plane wave is calculated to obtain the total Group Plane wave delayed excitation of array elements; repeat each plane wave delayed excitation The excitation groups are arranged to form a total different transmission codes; using the generated Different transmission codes are used to transmit positive pulses and negative pulses respectively, and the Group The coded transmission echo data of the channel; performing specific harmonic decoding on the coded transmission echo data to obtain Harmonic echo data of plane wave transmission at angles; The harmonic echo data of the plane waves at each angle are subjected to frequency domain beam synthesis and signal processing to obtain the final ultrasonic image.

[0009] Furthermore, the delay excitation of each plane wave is repeated The excitation groups are arranged to form a total Different transmission codes include: delaying each plane wave excitation according to Spaced Repetition times to form an excitation group, and the excitation group is pressed The intervals are arranged in a predetermined order in time to form a common Different transmission codes.

[0010] Further, the incentive group is The intervals are arranged in a predetermined order in time to form a common Different transmission codes include: The intervals are arranged in time according to the patrol-precedence method, generating Different transmission codes, The arrangement according to the round-robin method includes: for the first The transmission code is The stimulus group is placed before the other stimulus groups in time, and the other stimulus groups are arranged in the original order, among which, Not greater than A positive integer.

[0011] Further, the use of the generated Different transmission codes are used to transmit positive pulses and negative pulses respectively, including: each time the generated After the positive pulse transmission of any one of the different transmission codes, a negative pulse transmission using the same transmission code follows.

[0012] Further, the encoding transmission echo data is subjected to specific harmonic decoding to obtain The invention discloses a method for obtaining harmonic echo data of plane wave emission at each angle, comprising: adding coded emission echo data of two adjacent positive pulses and negative pulses, eliminating fundamental wave information, and leaving only harmonic echo data; performing Fourier transform on the harmonic echo data, and constructing a frequency domain linear equation group according to the emission coding; solving the linear equation group of each frequency in the harmonic frequency band of the transducer, and obtaining the harmonic echo frequency domain data of the plane wave individually excited at each angle.

[0013] Further, constructing a frequency domain linear equation system according to the transmission coding includes: constructing the first linear equation system according to the following formula: The frequency domain linear equation of the transmit code is:

[0014]

[0015]

[0016] in, Representative The frequency domain echo data of the transmitted code is Representative The frequency domain harmonic echo data corresponding to the plane wave of angles, Represents the incentive group The phase rotation multiplier corresponding to the repetition is, represents the phase rotation multiplier corresponding to adjacent excitation groups, represents the imaginary unit, Represents the angular frequency of the Fourier transform.

[0017] Furthermore, solving the linear equations for each frequency in the harmonic frequency band of the transducer includes: if the harmonic frequency band of the transducer is , then by default The frequency component of the echo data outside the interval is 0. Among them, the Frequency domain beam synthesis is performed on the harmonic echo data of the plane wave at each angle, including: The harmonic echo data of the plane wave at each angle are respectively Frequency domain beamforming is performed within the .

[0018] Further, the calculation of the excitation delay corresponding to the plane wave at each angle includes: The following formula is used to calculate the The first The excitation delay corresponding to the plane wave of angles is:

[0019] in, Representative The first The excitation delay corresponding to the plane wave of angles is: Representative The inclination angle of the plane wave is Representative The horizontal coordinate of the transducer array element, represents the estimated speed of sound in the imaging area; According to the above formula, we can calculate all All the angles of the plane wave launch The excitation delay of each transducer array element.

[0020] Another aspect of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the ultrasonic plane wave harmonic imaging method described above are implemented.

[0021] Another aspect of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the ultrasonic plane wave harmonic imaging method described above are implemented.

[0022] The ultrasonic plane wave harmonic imaging method, medium and electronic device of one or more embodiments of the present application significantly increase the energy of ultrasound emitted per unit time by applying coded excitation to plane wave harmonic imaging, and decode harmonics in the frequency domain and perform beam synthesis. Under the premise of ensuring high frame rate, high resolution and high contrast, the signal-to-noise ratio of the harmonic signal is significantly improved and the imaging depth is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a flow chart of an ultrasonic plane wave harmonic imaging method according to an embodiment of the present application.

[0024] Figure 2 This is a schematic diagram of the corresponding relationship between the plane wave emission angle and its excitation delay according to an embodiment of the present application.

[0025] Figure 3 The present invention is a flowchart of generating a transmission code according to a patrol pre-position method according to an embodiment of the present application.

[0026] Figure 4 A schematic diagram comparing positive and negative pulse excitation according to an embodiment of the present application.

[0027] Figure 5 It is a schematic diagram of using three transmission codes to transmit positive pulses and negative pulses respectively according to an embodiment of the present application.

[0028] Figure 6A schematic block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0030] Ultrasonic plane wave harmonic imaging is an imaging technology with high frame rate, high resolution and high contrast. However, due to the low amplitude of the harmonic component and poor signal-to-noise ratio, the imaging depth of harmonic imaging is limited, which in turn prevents doctors from making reliable diagnoses of deep tissues.

[0031] The coded excitation technology can transmit more signal energy in the same time by transmitting ultrasound with a specific coding form, thereby significantly increasing the average transmission power and improving the signal-to-noise ratio of the echo signal. The present application provides an ultrasonic plane wave harmonic imaging method, which can overcome the disadvantage of poor signal-to-noise ratio and improve the practical value of the technology by applying coded excitation to plane wave harmonic imaging.

[0032] The ultrasonic plane wave harmonic imaging method, medium and electronic device of each embodiment of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0033] Figure 1 The present invention discloses a schematic flow chart of an ultrasonic plane wave harmonic imaging method according to an embodiment of the present invention. Figure 1 As shown, an ultrasonic plane wave harmonic imaging method according to an embodiment of the present application may include steps S1 to S5.

[0034] Step S1: Control with A linear array of transducer elements is used to transmit and receive data to determine the The excitation delay corresponding to each angle plane wave is calculated to obtain the total Group Plane wave delayed excitation of array elements.

[0035] Figure 2 A schematic diagram of the corresponding relationship between the plane wave emission angle and its excitation delay in one embodiment of the present application is disclosed. Figure 2 As shown, in order to make the linear array emit a plane wave with a specific angle, it is necessary to apply excitation to each transducer element at different time points.

[0036] Assume The inclination angle of a plane wave is , then the first The first The excitation delay corresponding to the plane wave of angles is: (1) in, Representative The first The excitation delay corresponding to the plane wave of angles is: Representative The inclination angle of the plane wave is Representative The horizontal coordinate of the transducer array element, Represents the estimated speed of sound in the imaged area.

[0037] Then, according to the above formula (1), we can get all All the angles of the plane wave launch The excitation delay of each transducer array element.

[0038] Step S2: Repeat each plane wave delay excitation The excitation groups are formed and these excitation groups are arranged to form a common Different transmission codes.

[0039] In some embodiments, each plane wave delayed excitation is Spaced Repetition times to form an incentive group, and then press these incentive groups The intervals are arranged in a predetermined order in time to form a common Different transmission codes.

[0040] Optionally, the stimulus groups can be grouped The intervals are arranged in time according to the patrol-precedence method, generating Different transmission codes.

[0041] Arrangement according to the round-robin method includes: The transmission code is The stimulus group is placed before the other stimulus groups in time, and the other stimulus groups are arranged in the original order, among which, Not greater than A positive integer.

[0042] Figure 3 A schematic diagram of a process for generating a transmission code according to a patrol pre-positioning method according to an embodiment of the present application is disclosed, wherein: Figure 3The plane waves at three different angles (i.e. ) and each angle plane wave is repeated twice (i.e. ), three different emission coding processes are generated. The details are as follows: like Figure 3 As shown, first, each angle plane wave is transformed into The interval excitation is repeated twice, that is, the 1st angle plane wave excitation is repeated twice, the 2nd angle plane wave excitation is repeated twice, and the 3rd angle plane wave excitation is repeated twice, to obtain three excitation groups, namely the 1st angle excitation group, the 2nd angle excitation group, and the 3rd angle excitation group.

[0043] Next, the three stimulus groups are arranged in time The intervals are arranged according to the patrol advance method to obtain three types of transmission codes.

[0044] For the first type of transmission coding, the first angle excitation group is ranked first, followed by the second angle excitation group and the third angle excitation group.

[0045] For the second transmission code, the second angle excitation group is ranked first, followed by the first angle excitation group and the third angle excitation group.

[0046] For the third transmission code, the third angle excitation group is ranked first, followed by the first angle excitation group and the second angle excitation group.

[0047] Step S3: Use the generated Different transmission codes are used to transmit positive pulses and negative pulses respectively, and the Group The channel's coded transmit echo data.

[0048] By changing the polarity of the excitation signal, positive and negative pulse excitation can be obtained. Figure 4 A comparative schematic diagram of positive and negative pulse excitation of an embodiment of the present application is disclosed. Figure 4 As shown, the solid line represents positive pulse excitation and the dotted line represents negative pulse excitation.

[0049] In step S3, each time the generated After the positive pulse transmission of any one of the different transmission codes, a negative pulse transmission using the same transmission code is followed. That is, for each transmission code, a positive pulse transmission and receiving collection are first performed, followed by a negative pulse transmission and receiving collection.

[0050] Figure 5 The use of an embodiment of the present application is disclosed Figure 3 The three transmission codes shown are schematic diagrams for transmitting positive pulses and negative pulses respectively. Figure 5 As shown, for Figure 3 The three transmission codes shown (i.e. ), the first transmission can be transmitted with a positive pulse of the first transmission code, the second transmission can be transmitted with a negative pulse of the first transmission code, the third transmission can be transmitted with a positive pulse of the second transmission code, the fourth transmission can be transmitted with a negative pulse of the second transmission code, the fifth transmission can be transmitted with a positive pulse of the third transmission code, and the sixth transmission can be transmitted with a negative pulse of the third transmission code. A total of six transmissions and receiving collections are performed.

[0051] Step S4: Perform specific harmonic decoding on the encoded transmission echo data to obtain Harmonic echo data of plane wave transmission at different angles.

[0052] In some embodiments, step S4 may include steps S41 to S43.

[0053] In step S41, the coded transmission echo data of two adjacent positive pulse and negative pulse transmissions are added. The change of excitation polarity will only change the polarity of the fundamental wave, but not the polarity of the harmonics, so such addition will eliminate the fundamental wave information and only leave the harmonic echo data.

[0054] In step S42, Fourier transform is performed on the harmonic echo data, and a frequency domain linear equation group is constructed according to the transmit coding.

[0055] In some embodiments, the first The frequency domain linear equation of the transmit code is: (2) in, Representative The frequency domain echo data of the transmitted code is Representative The frequency domain harmonic echo data corresponding to the plane wave of angles, Representatives within the incentive group The phase rotation multiplier corresponding to the repetition is, Represents the phase rotation multiplier corresponding to adjacent excitation groups.

[0056] It can be given by the following formula (3): (3) in, represents the imaginary unit, Represents the angular frequency of the Fourier transform.

[0057] It can be given by the following formula (4): (4) In step S43, the linear equations of each frequency are solved in the harmonic frequency band of the transducer to obtain the frequency domain data of harmonic echoes excited by the plane wave at each angle.

[0058] If the harmonic frequency band of the transducer is , then by default The frequency component of the echo data outside the interval is 0.

[0059] Step S5: The harmonic echo data of the plane waves at each angle are subjected to frequency domain beam synthesis and signal processing to obtain the final ultrasonic image.

[0060] Specifically, The harmonic echo data of the plane wave at each angle are respectively Frequency domain beamforming is performed in the image processing unit without the need for inverse Fourier transform to obtain time domain echo data. After that, coherent superposition, envelope extraction, logarithmic compression and other processing are performed to obtain the final ultrasound image.

[0061] Understandably, Figure 1 The steps S1 to S5 shown are only names given to the steps for distinguishing each other, and do not represent the order in which the steps are executed.

[0062] The ultrasonic plane wave harmonic imaging method of the present application significantly increases the energy of ultrasound emitted per unit time by applying coded excitation to plane wave harmonic imaging, and decodes harmonics in the frequency domain and performs beam synthesis. Under the premise of ensuring high frame rate, high resolution and high contrast, the signal-to-noise ratio of the harmonic signal is significantly improved and the imaging depth is increased.

[0063] The present application also provides a computer-readable storage medium. The storage medium stores a computer program, which, when executed by a processor, implements the above Figure 1 The steps of the ultrasonic plane wave harmonic imaging method are shown.

[0064] The present application also provides an electronic device 600 . Figure 6 A schematic block diagram of an electronic device 600 according to an embodiment of the present application is disclosed. Figure 6As shown, an electronic device 600 of an embodiment of the present application includes a processor 601, an internal bus 602, a network interface 603, a memory 604 and a non-volatile memory 605, and may also include hardware required for other services. The processor 601 can read the corresponding computer program from the non-volatile memory 605 into the memory 604 and then run it to implement the steps of the ultrasonic plane wave harmonic imaging method as described above. Of course, in addition to the software implementation, the present application does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic components.

[0065] It is understandable that, for the convenience of description, the above device is described by dividing the functions into modules. Of course, when implementing the present application, the functions of each module can also be implemented in the same or multiple software and / or hardware.

[0066] The ultrasonic plane wave harmonic imaging method, medium, and electronic device of one or more embodiments of the present application may have at least the following beneficial technical effects: (1) The coding scheme used is simple and effective; (2) The fundamental component is eliminated by adding positive and negative pulses to avoid the aliasing of the fundamental and harmonic components, and the amplitude of the harmonic component is increased by 2 times (the signal-to-noise ratio is times); (3) By including the excitation of all M angle plane waves in one transmission, the amplitude of the harmonic component is further increased to 2M times (signal-to-noise ratio is times); (4) By repeating K times in each angle plane wave excitation group, the amplitude of the harmonic component is further increased to 2MK times (signal-to-noise ratio is times); (5) The computation is simplified by performing decoding and beamforming within the harmonic frequency band.

[0067] The ultrasonic plane wave harmonic imaging method, medium and electronic device provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the ultrasonic plane wave harmonic imaging method, medium and electronic device in the embodiments of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. An ultrasonic plane wave harmonic imaging method, characterized in that: include: Control has A linear array of transducer elements is used to transmit and receive data to determine the The excitation delay corresponding to each angle plane wave is calculated to obtain the total Group Plane wave delayed excitation of array elements; Repeat each plane wave delay excitation The excitation groups are arranged to form a total Different transmission codes; Use the generated Different transmission codes are used to transmit positive pulses and negative pulses respectively, and the Group The channel's coded transmission echo data; The coded transmission echo data is subjected to specific harmonic decoding to obtain Harmonic echo data of plane wave transmission at each angle; right The harmonic echo data of the plane waves at each angle are subjected to frequency domain beam synthesis and signal processing to obtain the final ultrasonic image.

2. The method according to claim 1, characterized in that: Each plane wave delay excitation is repeated The excitation groups are arranged to form a total Different transmission codes, including: Each plane wave delay excitation is pressed Spaced Repetition times to form an excitation group, and the excitation group is pressed The intervals are arranged in a predetermined order in time to form a common Different transmission codes.

3. The method according to claim 2, characterized in that: The excitation group is The intervals are arranged in a predetermined order in time to form a common Different transmission codes, including: The stimulus group is pressed The intervals are arranged in time according to the patrol-precedence method, generating Different transmission codes, The arrangement according to the round-robin method includes: for the first The transmission code is The stimulus group is placed before the other stimulus groups in time, and the other stimulus groups are arranged in the original order, among which, Not greater than A positive integer.

4. The method according to claim 3, characterized in that: The use of the generated Different transmission codes for positive pulse and negative pulse transmission include: Each time you use the generated After the positive pulse transmission of any one of the different transmission codes, a negative pulse transmission using the same transmission code follows.

5. The method according to claim 4, characterized in that: The specific harmonic decoding is performed on the encoded transmission echo data to obtain Harmonic echo data for plane wave transmission at each angle, including: Add the coded transmission echo data of two adjacent positive pulses and negative pulses, eliminate the fundamental wave information, and only leave the harmonic echo data; Performing Fourier transformation on the harmonic echo data, and constructing a frequency domain linear equation group according to the transmission code; The linear equations of each frequency are solved in the harmonic frequency band of the transducer to obtain the frequency domain data of harmonic echoes excited by plane waves at each angle.

6. The method according to claim 5, characterized in that: The constructing of the frequency domain linear equations according to the transmission coding comprises: The following formula is used to construct the The frequency domain linear equation of the transmit code is: in, Representative The frequency domain echo data of the transmitted code is Representative The frequency domain harmonic echo data corresponding to the plane wave of angles, Represents the incentive group The phase rotation multiplier corresponding to the repetition is, represents the phase rotation multiplier corresponding to adjacent excitation groups, represents the imaginary unit, Represents the angular frequency of the Fourier transform.

7. The method according to claim 6, characterized in that: The linear equations for solving each frequency in the harmonic frequency band of the transducer include: If the harmonic frequency band of the transducer is , then by default The frequency component of the echo data outside the interval is 0. Among them, the Frequency domain beam synthesis is performed on the harmonic echo data of the plane wave at each angle, including: The harmonic echo data of the plane wave at each angle are respectively Frequency domain beamforming is performed within the .

8. The method according to claim 1, characterized in that: The calculation of the excitation delay corresponding to the plane waves at each angle comprises: The following formula is used to calculate the The first The excitation delay corresponding to the plane wave of angles is: in, Representative The first The excitation delay corresponding to the plane wave of angles is: Representative The inclination angle of the plane wave is Representative The horizontal coordinate of the transducer array element, represents the estimated speed of sound in the imaging area; According to the above formula, we can calculate all All the angles of the plane wave launch The excitation delay of each transducer array element.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the ultrasonic plane wave harmonic imaging method according to any one of claims 1 to 8 are implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the ultrasonic plane wave harmonic imaging method according to any one of claims 1 to 8 are implemented.

Images