阅读说明：本技术 超声显影装置和超声显影方法 (Ultrasonic developing apparatus and ultrasonic developing method ) 是由 张勇 杨成 于 2020-06-10 设计创作，主要内容包括：本发明涉及超声成像技术领域,涉及超声显影装置和超声显影方法,可以用于乳腺等疾病的诊断中,超声显影装置包括：编码发射模块用于激励换能器晶片阵列向待测区域连续发射N组超声平面波束,N为大于1的正整数；接收解码模块用于接收每组超声平面波束的回波；波束合成模块用于对接收到的各组超声平面波束的回波进行波束合成,对应获得连续的N帧显影图像；成像处理模块用于依次对N帧B模式图像进行斑点追踪,确定斑点在N帧B模式图像中的斑点变化信息；图像合成模块,用于将斑点变化信息的成像数据进行数据转换,获得包含斑点变化信息的B模式超声图像序列。超声显影装置和超声显影方法提高超声图像的分辨率,能够清楚显示微小血管血流状态。(The invention relates to the technical field of ultrasonic imaging, in particular to an ultrasonic developing device and an ultrasonic developing method, which can be used for diagnosing diseases such as mammary gland and the like, wherein the ultrasonic developing device comprises: the coding transmitting module is used for exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be detected, wherein N is a positive integer greater than 1; the receiving and decoding module is used for receiving the echo of each group of ultrasonic plane beams; the beam synthesis module is used for carrying out beam synthesis on the echoes of the received ultrasonic plane beams and correspondingly obtaining continuous N-frame developed images; the imaging processing module is used for sequentially carrying out speckle tracking on the N frames of B mode images and determining speckle change information of speckles in the N frames of B mode images; and the image synthesis module is used for performing data conversion on the imaging data of the speckle change information to obtain a B-mode ultrasonic image sequence containing the speckle change information. The ultrasonic developing device and the ultrasonic developing method improve the resolution of ultrasonic images and can clearly display the blood flow state of the tiny blood vessels.)

1. An ultrasonic developing apparatus, comprising:

the encoding and transmitting module is used for exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be detected, wherein N is a positive integer greater than 1;

a receive decoding module to receive echoes of each set of the ultrasound planar beams;

the beam synthesis module is used for carrying out beam synthesis on the received echoes of all groups of the ultrasonic plane beams and correspondingly obtaining continuous N-frame developed images;

an imaging processing module comprising a B-mode imaging module and a speckle tracking module; the B-mode imaging module is used for sequentially carrying out B-mode imaging on the N frames of developed images to obtain N frames of B-mode images; the speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images and determining speckle change information in the N frames of B mode images;

and the image synthesis module is used for synthesizing the speckle change information and the N frames of developed images to obtain a B-mode ultrasonic image sequence containing the speckle change information.

2. The ultrasonic imaging apparatus according to claim 1, wherein the coded transmission mode is configured to excite the transducer wafer array to continuously transmit N sets of ultrasonic planar beams toward the region to be measured by a pulse coded sequence;

the receiving and decoding module is used for carrying out matching decoding on the received echoes of each group of the ultrasonic plane beams.

3. The apparatus according to claim 1, wherein the coded transmission module is configured to excite the transducer wafer array to transmit the plurality of planar ultrasound beams of the nth set of planar ultrasound beams to the region under test along a plurality of different transmission angles through a pulse code sequence, where N is a positive integer greater than 1 and less than N.

4. The ultrasound imaging apparatus according to claim 3, wherein the beam-forming module is configured to perform beam-forming on the echoes of a plurality of ultrasound planar beams in the nth set of ultrasound planar beams to obtain an nth frame developed image, and the expression of the nth frame developed image is:

wherein x is the position of pixel points of the developed image of the nth frame in the direction parallel to the array of the transducer wafer;

z is the position of the pixel point of the nth frame developed image in the depth direction of the region to be detected;

x₁the position of the echo generated by the medium point corresponding to the pixel point of the developed image in the nth frame, which is received by the transducer wafer array;

alpha is the emission angle of the ultrasonic plane beam emitted by the transducer wafer array;

m is a positive integer greater than 1;

c is the propagation speed of the ultrasonic wave in the region to be detected;

the τ function represents: the time interval function from the time when the transducer wafer array sends out the ultrasonic plane wave to the medium point corresponding to the pixel point of the nth frame developed image to the time when the echo is received;

RF function representation: echo signals generated at the pixel positions of the n-th frame developed image are received by the transducer wafer array to form echo signal functions;

the s function represents: under a specific emission angle, developing an image function of the area to be detected;

the I function represents: and superposing the developed image functions of the area to be detected under a plurality of different emission angles to obtain an nth frame developed image function.

5. The sonography device according to claim 1, wherein said speckle tracking module is adapted to calculate an imaging variance of imaging data of corresponding pixels in adjacent frame B-mode images; determining static pixel points and dynamic pixel points according to the imaging variance; and tracking the change information of the imaging data of the dynamic pixel points to form spot change information.

6. The ultrasound imaging apparatus according to claim 1, wherein the imaging processing module further comprises a filtering module, the filtering module is configured to sequentially filter the N frames of B-mode images to suppress speckle noise;

the filtering module outputs the N frames of B-mode images after filtering to the speckle tracking module;

the speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images after speckle noise is suppressed, and determining speckle change information in the N frames of developed images;

the image synthesis module is used for displaying the spot change information of the developed image spots on the B-mode image of the corresponding frame in an overlapped mode.

7. The sonography device of claim 6, wherein said filtering module employs any one or more of an average filter, a median filter, a Lee filter, a Sigma filter, and a Frost filter to filter said speckle variation information to suppress speckle noise.

8. An ultrasonic imaging method, comprising the steps of:

exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be measured, wherein N is a positive integer greater than 1;

receiving echoes of each set of the ultrasound planar beams;

performing beam synthesis on the received echoes of each group of ultrasonic plane beams to correspondingly obtain continuous N-frame developed images;

sequentially carrying out B-mode imaging on the N developed images to obtain N frames of B-mode images;

sequentially carrying out speckle tracking on the N frames of B mode images, and determining speckle change information in the N frames of B mode images;

and synthesizing the speckle change information with the N frames of developed images to obtain a B-mode ultrasonic image sequence containing the speckle change information.

9. The method of ultrasonic imaging according to claim 8 wherein the exciting transducer wafer array continuously transmits N sets of planar ultrasonic beams to the region of interest, comprising:

through the pulse coding sequence, the transducer wafer array is excited to continuously emit N groups of ultrasonic plane wave beams to the area to be measured;

the step of receiving echoes for each set of the ultrasound planar beams further comprises: and carrying out matched decoding on the received echoes of each group of the ultrasonic plane beams.

10. The method of ultrasonic imaging according to claim 9 wherein the exciting transducer wafer array continuously transmits N sets of planar ultrasonic beams to the region of interest, comprising:

and exciting the transducer wafer array to emit a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to the region to be detected along a plurality of different emission angles through a pulse coding sequence, wherein N is a positive integer which is more than 1 and less than N.

Technical Field

The invention relates to the technical field of ultrasonic imaging, in particular to an ultrasonic developing device and an ultrasonic developing method.

Background

In a medical ultrasonic imaging system, an ultrasonic wave is reflected and scattered at a tissue interface of a scanning region, and an ultrasonic image in the scanning region is obtained by receiving and processing an echo signal containing tissue characteristic information.

Because the blood flow imaging has the limitations of resolution and sensitivity, and the tissue structure of the blood vessel of the human body is complex, the imaging is difficult especially for the tiny blood vessels with small blood flow and low blood flow speed; however, stable and reliable blood flow visualization of small blood vessels can assist a doctor in the purpose of discriminating the progress of a disease, for example, the degree of plaque stability from the internal blood supply of a carotid plaque.

The ultrasound imaging technology adopted by the related art at present is to clearly display the blood flow state of the tiny blood vessels by an imaging agent. However, since the imaging agent directly acts on the blood circulation, some people may have different degrees of allergic reactions to the imaging agent, and the risk is difficult to control.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides an ultrasound imaging apparatus and an ultrasound imaging method, which can clearly display the state of blood flow in a small blood vessel.

As a first aspect of the present invention, there is provided an ultrasonic developing device comprising:

the encoding and transmitting module is used for exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be detected, wherein N is a positive integer greater than 1;

a receive decoding module to receive echoes of each set of the ultrasound planar beams;

the beam synthesis module is used for carrying out beam synthesis on the received echoes of all groups of the ultrasonic plane beams and correspondingly obtaining continuous N-frame developed images;

an imaging processing module comprising a B-mode imaging module and a speckle tracking module; the B-mode imaging module is used for sequentially carrying out B-mode imaging on the N frames of developed images to obtain N frames of B-mode images; the speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images and determining speckle change information of speckles in the N frames of B mode images;

and the image synthesis module is used for synthesizing the speckle change information and the N frames of developed images to obtain a B-mode ultrasonic image sequence containing the speckle change information.

Optionally, the encoding and transmitting module is configured to excite the transducer wafer array to continuously transmit N groups of ultrasonic planar beams to the region to be measured through the pulse encoding sequence;

the receiving and decoding module is a receiving and decoding module and is used for matching and decoding the received echoes of each group of the ultrasonic plane beams.

Optionally, the encoding and transmitting module is configured to excite the transducer wafer array to transmit a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to the region to be detected along a plurality of different transmission angles through the pulse encoding sequence, where N is a positive integer greater than 1 and less than N.

Optionally, the beam forming module is configured to perform beam forming on echoes of a plurality of ultrasound planar beams in an nth group of ultrasound planar beams to obtain an nth frame developed image, where an expression of the nth frame developed image is:

wherein x is the position of pixel points of the developed image of the nth frame in the direction parallel to the array of the transducer wafer;

z is the position of the pixel point of the nth frame developed image in the depth direction of the region to be detected;

x₁the position of the echo generated by the medium point corresponding to the pixel point of the developed image in the nth frame, which is received by the transducer wafer array;

alpha is the emission angle of the ultrasonic plane beam emitted by the transducer wafer array;

m is a positive integer greater than 1;

c is the propagation speed of the ultrasonic wave in the region to be detected;

the τ function represents: the time interval function from the moment when the transducer wafer array sends out the ultrasonic plane wave to the medium point corresponding to the pixel point of the nth frame developed image to the moment when the echo is received;

RF function representation: the echo generated at the pixel point position of the nth frame developed image is received by the transducer wafer array to form an echo signal function;

the s function represents: under a specific emission angle, developing an image function of the area to be detected;

the I function represents: and superposing the developed image functions of the area to be detected under a plurality of different emission angles to obtain an nth frame developed image function.

Optionally, the blob tracking module is configured to calculate an imaging variance of imaging data of a corresponding pixel point in an adjacent frame B-mode image; determining static pixel points and dynamic pixel points according to the imaging variance; and tracking the change information of the imaging data of the dynamic pixel points to form spot change information.

Optionally, the imaging processing module further includes a filtering module, and the filtering module is configured to sequentially perform filtering processing on the N frames of B-mode images to suppress speckle noise;

the filtering module outputs the N frames of B-mode images after filtering to the speckle tracking module;

the speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images after speckle noise is suppressed, and determining speckle change information in the N frames of developed images;

the image synthesis module is used for displaying the spot change information of the developed image spots on the B-mode image of the corresponding frame in an overlapped mode.

Optionally, the filtering module performs filtering processing on the speckle variation information by using any one or more of a mean filter, a median filter, a Lee filter, a Sigma filter, and a Frost filter, so as to suppress speckle noise.

As a second aspect of the present invention, there is provided an ultrasonic developing method comprising the steps of:

exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be measured, wherein N is a positive integer greater than 1;

receiving echoes of each set of the ultrasound planar beams;

performing beam synthesis on the received echoes of each group of ultrasonic plane beams to correspondingly obtain continuous N-frame developed images;

sequentially carrying out B-mode imaging on the N developed images to obtain N frames of B-mode images;

sequentially carrying out speckle tracking on the N frames of B mode images, and determining speckle change information of speckles in the N frames of B mode images;

and synthesizing the speckle change information with the N frames of developed images to obtain a B-mode ultrasonic image sequence containing the speckle change information.

Optionally, the exciting transducer wafer array continuously emits N groups of ultrasonic planar beams to the region to be measured, including:

through the pulse coding sequence, the transducer wafer array is excited to continuously emit N groups of ultrasonic plane wave beams to the area to be measured;

the step of receiving echoes for each set of the ultrasound planar beams further comprises: and carrying out matched decoding on the received echoes of each group of the ultrasonic plane beams.

Optionally, the exciting transducer wafer array continuously emits N groups of ultrasonic planar beams to the region to be measured, including:

and exciting the transducer wafer array to emit a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to the region to be detected along a plurality of different emission angles through a pulse coding sequence, wherein N is a positive integer which is more than 1 and less than N.

The invention has the advantages that: the invention adopts N groups of ultrasonic plane beams to obtain N frames of developed images at a higher speed, shortens the time interval of adjacent frames, improves the resolution of ultrasonic images by combining beam synthesis and spot tracking, and can clearly display the blood flow state of the tiny blood vessels.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a block diagram of the first embodiment of the present invention.

Fig. 2 is a flow chart of an embodiment of the second aspect of the present invention.

Fig. 3 (left) is a diagram of conventional focused beam echoes received by a probe.

Fig. 3 (right) is a schematic diagram of the probe receiving the ultrasonic plane beam echo.

Fig. 4 (left) is a schematic diagram of a transducer wafer array transmitting and receiving a conventional focused beam.

Fig. 4 (right) is a schematic diagram of transducer wafer array transmit-receive ultrasound plane beam echoes.

Fig. 5 is a schematic diagram of the propagation of an ultrasonic plane beam in the region to be measured when the emission angle is 0 degrees.

Fig. 6 is a schematic diagram of propagation of an ultrasound plane beam in a region to be measured at an emission angle of α degrees (α is not 0).

Fig. 7 is a schematic diagram of a conventional single-pulse excitation imaging mode.

FIG. 8 is a schematic diagram of a pulse-coded excitation imaging mode.

Fig. 9 is a subsection of a spot in an ultrasound image of a thyroid gland.

Fig. 10 is an enlarged view of the area a in fig. 9.

Fig. 11 is an ultrasound diagram of the center of a spot in region a of fig. 9.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection can be mechanical connection or electrical connection; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As a first aspect of the present invention, there is provided an ultrasonic developing apparatus.

Example 1:

referring to fig. 1, the ultrasonic developing apparatus in the present embodiment includes:

and the coding transmitting module is used for exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to the region to be detected, wherein N is a positive integer greater than 1.

A receiving module for receiving echoes of each group of the ultrasound planar beams.

The beam synthesis module is used for carrying out beam synthesis on the received echoes of all groups of the ultrasonic plane beams, correspondingly obtaining continuous N frames of developed images and removing the artifacts in the N frames of developed images through an artifact removal algorithm; by performing beam synthesis on the echoes of each group of the ultrasonic plane beams, the contrast and the signal-to-noise ratio of each obtained frame of developed image can be improved.

The imaging processing module comprises a B-mode imaging module and a speckle tracking module; the B-mode imaging module is used for sequentially carrying out B-mode imaging on the N frames of developed images to obtain N frames of B-mode images; the speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images and determining speckle change information in the N frames of B mode imaging.

And the image synthesis module is used for synthesizing the speckle change information and the N frames of B mode images to obtain a B mode ultrasonic image sequence containing the speckle change information.

The image synthesis module can store the synthesized B-mode ultrasonic image sequence containing the speckle variation information in an image memory. The display module reads out the data in the image memory for display by scanning the image memory.

In the conventional ultrasonic imaging, multiple focused beams are transmitted to irradiate tissues for imaging (refer to fig. 3, left and 4), for example, single beam receiving is taken as an example, the focused beams need to be transmitted once for obtaining one receiving line, and if a frame of image has M scanning lines, a frame of image needs to be transmitted for M times; in a plane wave imaging mode (see right of fig. 3 and right of fig. 4), all array elements of the transducer are simultaneously excited to generate an ultrasonic plane wave parallel to the transducer, a sound field generated by the plane wave can effectively cover all regions of interest, all array elements also simultaneously receive echo signals after tissue scattering, and an ultrasonic image of the whole region can be obtained through the echo signals. Therefore, the plane wave only needs to be transmitted once to obtain one frame of image, and compared with the focused wave, the transmission frequency is reduced to 1/M. Even if the focused wave adopts a dual-beam, four-beam and other multi-beam parallel processing technology, the advantages of the plane wave in the aspect of reducing the transmission times are still considerable.

The tissue can be rapidly imaged by utilizing the ultrasonic plane wave beam (the speed of 1000 frames per second is preferred), the spots which can be displayed in a half-wavelength order are obviously moved in a short time between adjacent frames, the distribution of the spots is subjected to Gaussian fitting, the positions of the centers of the spots are positioned, and the high-resolution composite image of the spot change in the N frames of B-mode images is obtained by overlapping the spot change information of the N frames of B-mode images, so that the spot tracking is realized. The flow speed and direction of the fluid in the region to be measured can be deduced from the high-resolution composite image of the speckle variation.

Example 2:

referring to fig. 7 and 8, in order to improve the echo intensity of such tissues without reducing the resolution, the present embodiment provides an encoding and transmitting module in an ultrasound imaging apparatus based on embodiment 1, which is used to excite a transducer wafer array to continuously transmit N sets of ultrasound plane beams to a region to be measured through a pulse encoding sequence, for a small blood vessel with small blood flow and low blood flow rate, which has a problem of difficult imaging. The receiving and decoding module is used for carrying out decoding operation matched with the coding and transmitting module on the received echoes of each group of the ultrasonic plane beams.

In a conventional single-pulse-excitation ultrasound imaging system (see fig. 7), the transducer wafer of the probe receives the pulse excitation transmit ultrasound waves, and the resolution of the image depends on the impulse response of the transducer. In a coded excitation imaging system (see fig. 8), a coded signal with a long duration is used to excite a transducer, the pulse coded signal may be a series of long pulse sequences (such as barker codes) or a continuous signal with a certain duration (such as a chirp signal), and since the duration of the pulse coded signal is much longer than the pulse response time of the transducer, the energy carried by the signal can be increased, and the average power of an ultrasonic signal can be improved.

It should be explained that when the pulse code sequence is obtained by phase modulation or frequency modulation to excite the wafer array to transmit the ultrasonic plane beam, and when the echo of the ultrasonic plane beam is received, the received signal needs to be demodulated by using a corresponding demodulation method.

Example 3:

referring to fig. 5 and 6, since the single-angle plane wave has no focusing effect and low imaging contrast and signal-to-noise ratio, this embodiment provides, on the basis of embodiment 1, a coded transmitting module in the ultrasound imaging apparatus, configured to excite the transducer wafer array to transmit a plurality of ultrasound plane beams in the nth group of ultrasound plane beams to the region to be measured along a plurality of different transmitting angles through a pulse code sequence, where N is a positive integer greater than 1 and less than N.

It is to be explained that in a set of ultrasound plane beams, a plurality of ultrasound plane beams are comprised, each of said ultrasound plane beams being transmitted along a respective transmission angle, i.e. an echo of a set of ultrasound plane beams comprises echoes of a plurality of ultrasound plane beams, each of said echoes of an ultrasound plane beam being echoed along its respective reflection or scattering angle. To obtain a developed image of a specific frame, it is necessary to perform beamforming on the echoes of all the ultrasonic plane beams. The method comprises the steps of emitting a series of plane waves with different deflection angles, carrying out beam forming on echo data obtained by emitting at different angles, and then carrying out coherent superposition to improve the contrast and the signal-to-noise ratio of a final frame of image.

Specifically, the linear array probe is placed above the region to be measured (directly contacted with the surface of the medium in the region to be measured), and a beam forming module in the ultrasonic developing device is configured to perform beam forming on echoes of a plurality of ultrasonic planar beams in an nth group of ultrasonic planar beams to obtain an nth frame of developed image, where the expression of the nth frame of developed image is as follows:

wherein x is the position of pixel points of the developed image of the nth frame in the direction parallel to the array of the transducer wafer;

z is the position of the pixel point of the nth frame developed image in the depth direction of the region to be detected;

x₁and (c) the position of the echo generated by the medium point corresponding to the pixel point of the developed image in the nth frame, which is received by the transducer wafer array.

It should be explained that the tissue in the coverage space range of the emitted ultrasound plane beam can be displayed in the form of a developed image, where the pixel point is the minimum unit of the developed image, the medium point is the minimum unit of the tissue in the coverage space range of the ultrasound plane beam, and the brightness and the darkness of the corresponding pixel point are different due to the difference of the echo characteristics of the medium point.

Alpha is the emission angle of the ultrasonic plane beam emitted by the transducer wafer array;

c is the propagation speed of the ultrasonic wave in the region to be detected;

the τ function represents: the time interval function from the moment when the transducer wafer array sends out the ultrasonic plane wave to the medium point corresponding to the pixel point of the nth frame developed image to the moment when the echo is received;

RF function representation: the echo generated at the pixel point position of the nth frame developed image is received by the transducer wafer array to form an echo signal function;

the s function represents: and under a specific emission angle, developing an image function of the area to be measured.

Referring to fig. 5 and 6, for the case of no deflection, and α is 0 degrees, the formula is (3) instead The expression (2) shows that after single ultrasonic plane wave emission, echo signals obtained by array elements of the transducer wafer array along each transverse position are subjected to delay tau (alpha, x)₁X, z) are added.

And carrying out coherent superposition on the obtained developing image results under different emission angles, thereby obtaining the final developing image of the frame and improving the imaging quality of the final developing image of the frame. Wherein a series of different emission angles alpha is used_{i(i＝1，…m)}For each specific emission angle, a developed image corresponding to the specific emission angle can be obtained through the formula (2), and the developed images output under m different emission angles are subjected to coherent superposition to obtain a final developed image of one frame, namely the nth frame developed image.

Compared with the traditional line-by-line scanning imaging of focused waves, the ultrasonic plane wave imaging technology can obtain one frame of image by emitting once. The signal coherent combination obtained by the plane wave emission under a plurality of different emission angles can effectively improve the transverse resolution and the signal-to-noise ratio of the plane wave image. Experiment results show that the signal-to-noise ratio equivalent to that of the focusing wave can be achieved by coherent superposition of 9 angles; a coherent superposition of 17 angles achieves a lateral resolution comparable to that of the focused wave, while the number of shots of the plane wave is significantly reduced compared to the 83 shots required for the focused wave to form a frame of image.

The multi-angle coherent compounding can effectively improve the image quality of the plane wave imaging on the premise of keeping the frame rate advantage, so that the multi-angle coherent compounding can be applied to clinical application scenes with higher requirements on time resolution, and the ultrasonic plane wave technology based on the multi-angle coherent compounding can further promote the development of ultrasonic imaging in various clinical application fields.

Example 4:

in this embodiment, on the basis of embodiment 1, the speckle tracking module in the ultrasonic imaging apparatus is provided, and is configured to calculate an imaging variance of imaging data of a corresponding pixel point in an adjacent frame B-mode image; determining static pixel points and dynamic pixel points according to the imaging variance; and tracking the change information of the imaging data of the dynamic pixel points to form spot change information.

Specifically, the step of "tracking the change information of the imaging data of the dynamic pixel and forming the speckle change information" described in this embodiment specifically includes:

and determining the dynamic spots through the dynamic pixel points and the imaging data corresponding to the dynamic pixel points.

And determining the coordinates of the central dynamic pixel point positioned in the center of the dynamic spot through two-dimensional Gaussian surface fitting.

And determining the change information of the imaging data of the central dynamic pixel point as the spot change information of the dynamic spot.

If the coordinates of the central dynamic pixel point of the dynamic spot in the n-th frame of the B-mode image are needed to be obtained as shown in fig. 9 to 11, the two-dimensional gaussian surface fitting function is as follows:

taking logarithm of two sides of the formula (4), unfolding a square term, and finishing to obtain:

if the number of the dynamic pixel points of which the dynamic spots participate in the fitting is Z, writing the Z dynamic pixel points into a matrix form: a — B C, wherein:

a is a vector of Z1, the elements of which are:

a_i＝f_i×lnf_i(wherein i ═ 0, 1, 2 … … Z);

b is a matrix of Z5:

(wherein i ═ 0, 1, 2 … … Z);

c is a vector consisting of gaussian parameters:

for formulas (4) and (5):

g is the amplitude of Gaussian distribution;

x is the direction of the pixel point of the B-mode image of the nth frame parallel to the array of the transducer wafer;

z is the depth direction of the pixel point of the nth frame B mode image in the region to be detected;

for x₀The coordinate of the central dynamic pixel point in the x direction is shown;

for z₀The coordinate of the central dynamic pixel point in the z direction is obtained;

for σ_xThe standard deviation of each pixel point of the nth frame B mode image in the x direction is shown;

for σ_zThe standard deviation of each pixel point of the nth frame B mode image in the z direction is shown;

the column vectors of the Z participating fitting dynamic pixel point errors are: and E, fitting by using a least square method to ensure that the mean square error of the Z dynamic pixel points is minimum, namely:

when image data is processed, the amount of multiple data of pixel points is large, and for reducing the calculated amount, the matrix B is subjected to QR decomposition, namely: and B is QR, Q is an orthogonal matrix of Z and Z, R is an upper triangular matrix of Z and 5, and E is A-BC is derived as follows:

Q^TE＝Q^TA-Q^TBC＝Q^TA-RC (8)；

since Q is an orthogonal matrix, one can obtain:

order:

for formulas (7) to (9) above: wherein S is a 5-dimensional column vector; t is a Z-5 dimensional column vector; r₁5x5 upper triangular square matrix, mean square error:

for the above formula (10), when S ═ R₁C is the minimum value, so only need to solveCan find C^TX in (2)₀,z₀,σ_x,σ_z。

The ultrasonic plane wave beam can be used for imaging tissues quickly, the spots which are in half-wavelength magnitude are displayed by obviously moving in a short time between adjacent frames, the distribution of the spots is subjected to Gaussian fitting, the positions of the centers of the spots are positioned, and the high-resolution synthetic image of the spot change in the N frames of B-mode images is obtained by overlapping the spot change information of the N frames of B-mode images, so that the spot tracking is realized. The flow speed and direction of the fluid in the region to be measured can be deduced from the high-resolution composite image of the speckle variation.

Example 5:

in this embodiment, on the basis of embodiment 1, the imaging processing module in the ultrasonic imaging apparatus further includes a filtering module, where the filtering module is configured to sequentially perform filtering processing on N frames of B-mode images to suppress speckle noise; and the filtering module outputs the N frames of B-mode images after filtering to the speckle tracking module.

The speckle tracking module is used for sequentially carrying out speckle tracking on the N frames of B mode images after speckle noise is suppressed, and determining speckle change information in the N frames of B mode images.

The image synthesis module is used for displaying the spot change information of the B-mode image spots on the B-mode image of the corresponding frame in an overlapped mode. By overlapping and combining the speckle change information with the B-mode image, the B-mode ultrasonic image sequence stored in the image memory by the image combining module contains the speckle change information, so that the speckle change information of the B-mode image can be displayed in the image finally displayed by the display module.

The filtering module adopts any one or more of an average filter, a median filter, a Lee filter, a Sigma filter and a Frost filter to filter the speckle change information and inhibit speckle noise.

Specifically, when the imaging processing module performs filtering processing on the speckle variation information by using a Lee filter to suppress speckle noise, the local mean and local variance in a filtering window of 5x5 or 3x3 or other filtering windows are used to estimate the prior mean and variance of the speckle variation information, so as to perform filtering processing on the speckle variation information to suppress speckle noise.

As a second aspect of the present invention, there is provided an ultrasonic developing method.

Embodiment 1:

the ultrasonic developing method provided by the embodiment comprises the following steps:

s1: exciting the transducer wafer array to continuously transmit N groups of ultrasonic plane wave beams to a region to be measured, wherein N is a positive integer greater than 1;

s2: receiving echoes of each set of the ultrasound planar beams;

s3: performing beam synthesis on the received echoes of each group of ultrasonic plane beams, correspondingly obtaining continuous N frames of developed images, and removing artifacts in the N frames of developed images through an artifact removal algorithm; by performing beam synthesis on the echoes of each group of the ultrasonic plane beams, the contrast and the signal-to-noise ratio of each obtained frame of developed image can be improved.

S4: sequentially carrying out B-mode imaging on the N developed images to obtain N frames of B-mode images;

s5: sequentially carrying out speckle tracking on the N frames of B mode images, and determining speckle change information of speckles in the N frames of B mode images;

s6: and synthesizing the speckle variation information with the N frames of B mode images to obtain a B mode ultrasonic image sequence containing the speckle variation information. And storing the B-mode ultrasonic image sequence containing the speckle change information obtained after data conversion in an image memory. The display module reads out the data in the image memory for display by scanning the image memory.

The traditional ultrasonic imaging is to emit multiple focused beams to irradiate tissues for imaging, taking single beam receiving as an example, the focused beams need to pay the cost of emitting once when obtaining one receiving line, and if a frame of image has M scanning lines, a frame of image needs to be emitted for M times; in the plane wave imaging mode, all array elements of the transducer are simultaneously excited to generate an ultrasonic plane wave parallel to the transducer, a sound field generated by the plane wave can effectively cover all regions of interest, all array elements also simultaneously receive echo signals after tissue scattering, and the ultrasonic image of the whole region can be obtained through the echo signals. Therefore, the plane wave only needs to be transmitted once to obtain one frame of image, and compared with the focused wave, the transmission frequency is reduced to 1/M. Even if the focused wave adopts a dual-beam, four-beam and other multi-beam parallel processing technology, the advantages of the plane wave in the aspect of reducing the transmission times are still considerable.

The tissue can be rapidly imaged by utilizing the ultrasonic plane wave beam (the speed of 1000 frames per second is preferred), the spots which can be displayed in a half-wavelength order are obviously moved in a short time between adjacent frames, the distribution of the spots is subjected to Gaussian fitting, the positions of the centers of the spots are positioned, and the high-resolution composite image of the spot change in the N frames of B-mode images is obtained by overlapping the spot change information of the N frames of B-mode images, so that the spot tracking is realized. The flow speed and direction of the fluid in the region to be measured can be deduced from the high-resolution composite image of the speckle variation.

Embodiment 2:

in this embodiment, in addition to embodiment 1, in step S1 in embodiment 1: the method comprises the following steps of exciting a transducer wafer array to continuously emit N groups of ultrasonic plane wave beams to a region to be measured, wherein N is a positive integer greater than 1:

and through the pulse code sequence, the transducer wafer array is excited to continuously transmit N groups of ultrasonic plane wave beams to the region to be measured. And when the echoes of each group of the ultrasonic plane beams are received, matching and decoding the received echoes of each group of the ultrasonic plane beams, wherein the decoding algorithm is matched with the encoding algorithm during encoding transmission.

Since it is difficult to visualize a small blood vessel having a small blood flow rate and a low blood flow rate, the resolution is not reduced in order to increase the echo intensity of such a tissue. In a conventional single-pulse-excitation ultrasonic imaging system, a transducer wafer of a probe receives pulse excitation to transmit ultrasonic waves, and the resolution of an image depends on the impulse response of the transducer. In the coded excitation imaging system, a coded signal with a longer duration is used for exciting the transducer, the pulse coded signal can be a series of long pulse sequences (such as a barker code) or a continuous signal with a certain duration (such as a chirp signal), and the duration of the pulse coded signal is far longer than the pulse response time of the transducer, so that the energy carried by the signal can be increased, and the average power of an ultrasonic signal can be improved.

It should be explained that when the pulse code sequence is obtained by phase modulation or frequency modulation to excite the wafer array to transmit the ultrasonic plane beam, and when the echo of the ultrasonic plane beam is received, the received signal needs to be demodulated by using a corresponding demodulation method.

Embodiment 3:

in this embodiment, in addition to embodiment 1, in step S1 in embodiment 2: the method comprises the following steps of exciting a transducer wafer array to continuously emit N groups of ultrasonic plane wave beams to a region to be measured, wherein N is a positive integer greater than 1:

and exciting the transducer wafer array to emit a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to the region to be detected along a plurality of different emission angles through a pulse coding sequence, wherein N is a positive integer which is more than 1 and less than N.

Because the single-angle plane wave has no focusing effect and low imaging contrast and signal-to-noise ratio, the contrast and the signal-to-noise ratio of the final frame of image are improved by transmitting a series of plane waves with different deflection angles, performing beam synthesis on echo data obtained by transmitting the plane waves at different angles and then performing coherent superposition.

Embodiment 4:

in this embodiment, in addition to embodiment 3, in step S3 in embodiment 3: performing beam forming on the received echoes of each group of the ultrasonic plane beams, and correspondingly obtaining continuous N-frame developed images, wherein the method comprises the following steps: performing beam synthesis on echoes of a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to obtain an nth frame developed image, wherein the expression of the nth frame developed image is as follows:

wherein x is the position of pixel points of the developed image of the nth frame in the direction parallel to the array of the transducer wafer;

z is the position of the pixel point of the nth frame developed image in the depth direction of the region to be detected;

x₁the position of the echo generated by the medium point corresponding to the pixel point of the developed image in the nth frame, which is received by the transducer wafer array;

alpha is the emission angle of the ultrasonic plane beam emitted by the transducer wafer array;

c is the propagation speed of the ultrasonic wave in the region to be detected;

the τ function represents: the time interval function from the moment when the transducer wafer array sends out the ultrasonic plane wave to the medium point corresponding to the pixel point of the nth frame developed image to the moment when the echo is received;

RF function representation: the echo generated at the pixel point position of the nth frame developed image is received by the transducer wafer array to form an echo signal function;

the s function represents: and under a specific emission angle, developing an image function of the area to be measured.

Performing beam synthesis on the received echoes of each group of ultrasonic plane beams to correspondingly obtain continuous N-frame developed images; specifically, the method comprises the following steps: and the beam forming module in the ultrasonic developing device is used for carrying out beam forming on echoes of a plurality of ultrasonic plane beams in the nth group of ultrasonic plane beams to obtain the nth frame of developed image.

For the case of no deflection, and α is 0 degrees, the formula is (3) to obtain The expression (2) shows that after single ultrasonic plane wave emission, echo signals obtained by array elements of the transducer wafer array along each transverse position are subjected to delay tau (alpha, x)₁X, z) are added.

And carrying out coherent superposition on the obtained developing image results under different emission angles, thereby obtaining the final developing image of the frame and improving the imaging quality of the final developing image of the frame. Wherein a series of different emission angles alpha is used_{i(i＝1，。。。m)}For each specific emission angle, a developed image corresponding to the specific emission angle can be obtained through the formula (2), and the developed images output under m different emission angles are subjected to coherent superposition to obtain a final developed image of one frame, namely the nth frame developed image.

Embodiment 5:

in this embodiment, in addition to embodiment 1, in step S5 in embodiment 1: sequentially carrying out speckle tracking on the N frames of B mode images, and determining speckle change information of speckles in the N frames of B mode images, wherein the speckle change information comprises the following steps:

s51: calculating the imaging variance of imaging data of corresponding pixel points in adjacent frame B mode images;

s52: determining static pixel points and dynamic pixel points according to the imaging variance;

s53: and tracking the change information of the imaging data of the dynamic pixel points to form spot change information.

The ultrasonic plane wave beam can be used for imaging tissues quickly, the spots which are in half-wavelength magnitude are displayed by obviously moving in a short time between adjacent frames, the distribution of the spots is subjected to Gaussian fitting, the positions of the centers of the spots are positioned, and the high-resolution synthetic image of the spot change in the N frames of B-mode images is obtained by overlapping the spot change information of the N frames of B-mode images, so that the spot tracking is realized. The flow speed and direction of the fluid in the region to be measured can be deduced from the high-resolution composite image of the speckle variation.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.