阅读说明：本技术 一种螺旋超声断层成像方法及系统 (Spiral ultrasonic tomography method and system ) 是由 尉迟明 丁明跃 张求德 宋俊杰 刘阔林 刘昭辉 周亮 全朝辉 方小悦 武云 周权 于 2019-09-29 设计创作，主要内容包括：本发明属于超声成像领域,公开了一种螺旋超声断层成像方法及系统,其中方法是在超声探头沿Z轴匀速位移的前提下,利用超声探头的同步旋转或超声探头内发射阵元的循环切换,使各个超声波发射时刻下发射阵元的位置随时间在三维空间中的变化轨迹沿一条螺旋线或曲线分布；在超声探头沿Z轴匀速位移的过程中超声探头发射超声波并接收采集回波数据,采集到的回波数据经存储、及数据后处理即可实现对待测对象的超声断层成像。本发明通过对超声扫描过程中发射阵元的位置变化进行控制,得到的新型的螺旋超声断层三维扫描方法及相应系统,可以实现快速连续不间断的数据获取,保证在Z轴方向上获得更高的空间分辨率；也可利用多层冗余数据,提高图像信噪比。(The invention belongs to the field of ultrasonic imaging, and discloses a spiral ultrasonic tomography method and a system, wherein the method is characterized in that on the premise that an ultrasonic probe is displaced along a Z axis at a constant speed, the change track of the position of a transmitting array element in a three-dimensional space along with time at each ultrasonic transmitting time is distributed along a spiral line or a curve by utilizing the synchronous rotation of the ultrasonic probe or the cyclic switching of the transmitting array element in the ultrasonic probe; the ultrasonic probe transmits ultrasonic waves and receives collected echo data in the process that the ultrasonic probe moves at a constant speed along the Z axis, and the collected echo data can be stored and subjected to data post-processing to realize ultrasonic tomography of an object to be detected. According to the novel spiral ultrasonic tomography three-dimensional scanning method and the corresponding system, the position change of the transmitting array element in the ultrasonic scanning process is controlled, so that the rapid, continuous and uninterrupted data acquisition can be realized, and the higher spatial resolution can be obtained in the Z-axis direction; and the signal-to-noise ratio of the image can be improved by utilizing multiple layers of redundant data.)

1. A spiral ultrasonic tomography method is characterized in that on the premise that an ultrasonic probe is displaced along a Z axis at a constant speed, the synchronous rotation of the ultrasonic probe or the cyclic switching of transmitting array elements in the ultrasonic probe according to a preset hour direction is utilized, so that the changing tracks of the positions of the transmitting array elements in a three-dimensional space along with time when ultrasonic waves are transmitted are distributed along a spiral line or a curve mainly composed of a plurality of spiral lines; the ultrasonic probe transmits ultrasonic waves and receives collected echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed, and the collected echo data can realize ultrasonic tomography of an object to be detected through storage and data post-processing;

when the ultrasonic probe transmits ultrasonic waves every time, one array element serves as a transmitting array element, other array elements serve as receiving array elements, and echo data received by the receiving array elements carry tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe specifically comprises:

(i) carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the ultrasonic probe to rotate according to the preset rotation angular velocity, wherein the rotation angular velocity vector is kept fixed; or

(ii) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the ultrasonic probe to rotate according to the preset rotation angular velocity, wherein the vector magnitude of the rotation angular velocity is kept fixed, and the vector direction is switched according to the preset switching frequency; or

(iii) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the transmitting array elements in the ultrasonic probe to carry out circular switching according to the preset fixed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement; or

(iv) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the transmitting array elements in the ultrasonic probe to carry out circular switching according to the preset changed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement, and the changing frequency of the hour hand direction also meets the preset requirement;

the data post-processing specifically comprises: rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging image; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

2. The helical ultrasonic tomography method as claimed in claim 1, wherein the ultrasonic probe sequentially excites and transmits the ultrasonic waves at equal time intervals during the uniform displacement of the ultrasonic probe along the Z-axis, or the ultrasonic probe sequentially excites and transmits the ultrasonic waves according to the pre-selected partial array elements.

3. The helical ultrasonic tomography method as set forth in claim 1, wherein the ultrasonic probe is a ring-shaped ultrasonic probe or a concave array ultrasonic probe having a plurality of array elements uniformly distributed.

4. A helical ultrasonic tomography method as claimed in claim 3, wherein for the cyclic switching of the transmitting elements in the ultrasonic probe in the preset clockwise direction, the switching is performed by the participation of a plurality of adjacent elements in the ring-shaped ultrasonic probe or by the participation of a plurality of elements at fixed intervals in the ring-shaped ultrasonic probe.

5. A helical ultrasonic tomography method as claimed in claim 3, wherein for the cyclic switching of the transmitting elements in the ultrasonic probe in the preset clockwise direction, the switching is the switching of all the elements in the ring-shaped ultrasonic probe.

6. A spiral ultrasonic tomography device is characterized by comprising an ultrasonic probe, a Z-axis motion subsystem, a memory and a data post-processing module, wherein,

the Z-axis motion subsystem is used for driving the ultrasonic probe to move at a constant speed along the Z axis and enabling the ultrasonic probe to synchronously rotate, so that the change tracks of the positions of the transmitting array elements in the three-dimensional space along with time at the time of transmitting each ultrasonic wave are distributed along a spiral line or a curve mainly composed of a plurality of spiral lines;

the ultrasonic probe is used for transmitting ultrasonic waves and receiving and acquiring echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed; the ultrasonic probe comprises a plurality of array elements, wherein when ultrasonic waves are transmitted each time, one array element is used as a transmitting array element, other array elements are used as receiving array elements, and echo data received by each receiving array element carries tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z axis along the preset Z-axis direction and the preset displacement rate, and simultaneously keep the ultrasonic probe to rotate according to the preset rotation angular velocity, and the rotation angular velocity vector keeps fixed; or, the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z-axis along a preset Z-axis direction and a preset displacement rate, and simultaneously keep the ultrasonic probe to rotate according to a preset rotation angular velocity, the vector magnitude of the rotation angular velocity is kept fixed, and the vector direction is switched according to a preset switching frequency;

the memory is used for storing echo data acquired by the ultrasonic probe;

the data post-processing module is used for rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging graph; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

7. A spiral ultrasonic tomography device is characterized by comprising an ultrasonic probe, a Z-axis motion subsystem, a memory and a data post-processing module, wherein,

the Z-axis motion subsystem is used for driving the ultrasonic probe to move at a constant speed along the Z axis;

the transmitting array elements in the ultrasonic probe can be circularly switched according to a preset hour direction, so that the changing tracks of the positions of the transmitting array elements in the three-dimensional space along with time at each ultrasonic transmitting time are distributed along a spiral line or a curve mainly composed of a plurality of spiral lines; the ultrasonic probe is used for transmitting ultrasonic waves and receiving and acquiring echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed; the ultrasonic probe comprises a plurality of array elements, wherein when ultrasonic waves are transmitted each time, one array element is used as a transmitting array element, other array elements are used as receiving array elements, and echo data received by each receiving array element carries tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z axis along the preset Z-axis direction and the preset displacement rate, and meanwhile, the transmitting array elements in the ultrasonic probe are kept to perform circular switching according to the preset fixed hour-hand direction, and the switching frequency of the transmitting array elements meets the preset requirement; or, the ultrasonic probe can perform uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate under the driving of the Z axis motion subsystem, and simultaneously keep the transmitting array elements in the ultrasonic probe to perform circular switching according to the preset changed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement, and the changing frequency of the hour hand direction also meets the preset requirement;

the memory is used for storing echo data acquired by the ultrasonic probe;

the data post-processing module is used for rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging graph; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

8. The helical ultrasonic tomography apparatus as claimed in claim 6 or 7, further comprising a bed for carrying the object to be measured and preferably capable of providing water as an ultrasonic couplant medium between the ultrasonic probe and the object to be measured.

9. The helical ultrasonic tomography apparatus as set forth in claim 8, further comprising a water treatment subsystem for filtering impurities in the water as the ultrasonic couplant medium, removing bubbles from the water, and controlling water circulation.

Technical Field

The invention belongs to the field of ultrasonic imaging, and particularly relates to a spiral ultrasonic tomography method and system.

Background

Ultrasonic imaging refers to transmitting ultrasonic waves to an object to be scanned by using an ultrasonic probe, enabling the ultrasonic waves to interact with the object to be scanned in a reflection, scattering, diffraction and the like, then detecting ultrasonic echoes, and analyzing and processing echo data to obtain an ultrasonic reflection image. The ultrasonic imaging technology is widely applied to clinical medical detection of ophthalmology, obstetrics and gynecology, gastroenterology and the like. Compared with other image modes, the clinical ultrasonic detection has the advantages of no radiation to human bodies, low detection cost, real-time imaging and the like. In the last two thirty years, with the improvement of the manufacturing and processing technology of the ultrasonic probe and the rapid development of the computer technology, the ultrasonic tomography technology has made great progress. The ultrasonic tomography technology uses an ultrasonic probe to transmit ultrasonic waves, simultaneously detects ultrasonic echoes scattered from the periphery of an object to be imaged, and reconstructs various acoustic parameters including a reflection map, a sound velocity map and an attenuation map according to echo data.

Ultrasound tomography belongs to the field of ultrasound imaging and also requires the use of ultrasound excitation followed by the reception of echoes. The difference is that the ultrasonic tomography receiving aperture is far larger than that of the common B-mode ultrasound, and the transmission echoes can be obtained, so that more imaging modes are derived; but also, therefore, the amount of data obtained is larger and the computational complexity is higher.

Ultrasound tomography generally uses a single array element transmit, excitation acquisition mode where all other array elements receive. Because the array elements are more in number and the receiving aperture is large, the spatial resolution is higher. After the single-section scanning is finished, the motor moves for a certain distance and then is static, each array element on the circular array is sequentially excited, all the array elements receive at the same time, and the scanning of a second layer is finished; the process is repeated to realize the scanning imaging of the three-dimensional space. In the field of tomographic scanning, such a scanning mode is called a step-and-scan mode. The mode needs to go through repeated stepping and stopping, so that the shaking of the ultrasonic transmission medium is easily caused, and artifacts are caused; moreover, because the scanning is stopped and then the movement is carried out, the three-dimensional scanning time is very long, and the comfort of the patient is greatly influenced; on the other hand, the tomography of the step-and-scan method can only reflect the section information of a specific position when the motor stops, and accurate data cannot be obtained between sections, so that missed diagnosis may be caused, and the resolution of the image obtained by the method in the Z-axis direction is low. At present, the mainstream tomography scanning mode is mainly a stepping mode, and a novel three-dimensional scanning mode is urgently needed to shorten the scanning time and improve the Z-axis resolution.

Disclosure of Invention

Aiming at the defects of the conventional mainstream tomography step scanning mode, the invention aims to provide a spiral ultrasonic tomography method and a system, wherein the position change of an emission array element in the ultrasonic scanning process is controlled, so that the emission array element emits in a spiral track or an approximate spiral track, and the obtained novel spiral ultrasonic tomography three-dimensional scanning method and the corresponding system can realize rapid, continuous and uninterrupted data acquisition and ensure that higher spatial resolution is obtained in the Z-axis direction; and the signal-to-noise ratio of the image can be improved by utilizing multiple layers of redundant data.

In order to achieve the above object, according to one aspect of the present invention, there is provided a spiral ultrasonic tomography method, which is characterized in that under the premise that an ultrasonic probe is displaced along a Z axis at a constant speed, by using synchronous rotation of the ultrasonic probe or cyclic switching of transmitting array elements in the ultrasonic probe in a preset hour-hand direction, the changing trajectory of the positions of the transmitting array elements in a three-dimensional space along with time at the time of transmitting each ultrasonic wave is distributed along a spiral line or along a curve mainly composed of a plurality of spiral lines; the ultrasonic probe transmits ultrasonic waves and receives collected echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed, and the collected echo data can realize ultrasonic tomography of an object to be detected through storage and data post-processing;

when the ultrasonic probe transmits ultrasonic waves every time, one array element serves as a transmitting array element, other array elements serve as receiving array elements, and echo data received by the receiving array elements carry tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe specifically comprises:

(i) carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the ultrasonic probe to rotate according to the preset rotation angular velocity, wherein the rotation angular velocity vector is kept fixed; or

(ii) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the ultrasonic probe to rotate according to the preset rotation angular velocity, wherein the vector magnitude of the rotation angular velocity is kept fixed, and the vector direction is switched according to the preset switching frequency; or

(iii) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the transmitting array elements in the ultrasonic probe to carry out circular switching according to the preset fixed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement; or

(iv) Carrying out uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate, and simultaneously keeping the transmitting array elements in the ultrasonic probe to carry out circular switching according to the preset changed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement, and the changing frequency of the hour hand direction also meets the preset requirement;

the data post-processing specifically comprises: rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging image; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

As a further preferred aspect of the present invention, during the uniform displacement of the ultrasonic probe along the Z-axis, the ultrasonic probe sequentially excites and transmits the ultrasonic waves at equal time intervals, or the ultrasonic probe sequentially excites and transmits the ultrasonic waves according to the pre-selected partial array elements.

As a further preferred aspect of the present invention, the ultrasonic probe is a ring-shaped ultrasonic probe or a concave array ultrasonic probe, and has a plurality of array elements uniformly distributed.

As a further preferred aspect of the present invention, for the cyclic switching of the transmitting array elements in the ultrasound probe in the preset hour direction, the switching is performed by participation of a plurality of adjacent array elements in the ring-shaped ultrasound probe, or by participation of a plurality of array elements at fixed intervals in the ring-shaped ultrasound probe.

In a further preferred embodiment of the present invention, the cyclic switching of the transmitting elements in the ultrasound probe in the predetermined clockwise direction is performed by switching all the elements in the ring-shaped ultrasound probe.

According to another aspect of the present invention, there is provided a helical ultrasonic tomography apparatus comprising an ultrasonic probe, a Z-axis motion subsystem, a memory, and a data post-processing module, wherein,

the Z-axis motion subsystem is used for driving the ultrasonic probe to move at a constant speed along the Z axis and enabling the ultrasonic probe to synchronously rotate, so that the change tracks of the positions of the transmitting array elements in the three-dimensional space along with time at the time of transmitting each ultrasonic wave are distributed along a spiral line or a curve mainly composed of a plurality of spiral lines;

the ultrasonic probe is used for transmitting ultrasonic waves and receiving and acquiring echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed; the ultrasonic probe comprises a plurality of array elements, wherein when ultrasonic waves are transmitted each time, one array element is used as a transmitting array element, other array elements are used as receiving array elements, and echo data received by each receiving array element carries tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z axis along the preset Z-axis direction and the preset displacement rate, and simultaneously keep the ultrasonic probe to rotate according to the preset rotation angular velocity, and the rotation angular velocity vector keeps fixed; or, the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z-axis along a preset Z-axis direction and a preset displacement rate, and simultaneously keep the ultrasonic probe to rotate according to a preset rotation angular velocity, the vector magnitude of the rotation angular velocity is kept fixed, and the vector direction is switched according to a preset switching frequency;

the memory is used for storing echo data acquired by the ultrasonic probe;

the data post-processing module is used for rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging graph; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

According to still another aspect of the present invention, there is provided a helical ultrasonic tomography apparatus comprising an ultrasonic probe, a Z-axis motion subsystem, a memory, and a data post-processing module, wherein,

the Z-axis motion subsystem is used for driving the ultrasonic probe to move at a constant speed along the Z axis;

the transmitting array elements in the ultrasonic probe can be circularly switched according to a preset hour direction, so that the changing tracks of the positions of the transmitting array elements in the three-dimensional space along with time at each ultrasonic transmitting time are distributed along a spiral line or a curve mainly composed of a plurality of spiral lines; the ultrasonic probe is used for transmitting ultrasonic waves and receiving and acquiring echo data in the process that the ultrasonic probe moves along the Z axis at a constant speed; the ultrasonic probe comprises a plurality of array elements, wherein when ultrasonic waves are transmitted each time, one array element is used as a transmitting array element, other array elements are used as receiving array elements, and echo data received by each receiving array element carries tomography information of a local area of an object to be detected near a plane where the ultrasonic probe is located;

the ultrasonic probe can be driven by the Z-axis motion subsystem to perform uniform-speed displacement along the Z axis along the preset Z-axis direction and the preset displacement rate, and meanwhile, the transmitting array elements in the ultrasonic probe are kept to perform circular switching according to the preset fixed hour-hand direction, and the switching frequency of the transmitting array elements meets the preset requirement; or, the ultrasonic probe can perform uniform-speed displacement along the Z axis along the preset Z axis direction and the preset displacement rate under the driving of the Z axis motion subsystem, and simultaneously keep the transmitting array elements in the ultrasonic probe to perform circular switching according to the preset changed hour hand direction, wherein the switching frequency of the transmitting array elements meets the preset requirement, and the changing frequency of the hour hand direction also meets the preset requirement;

the memory is used for storing echo data acquired by the ultrasonic probe;

the data post-processing module is used for rearranging and encoding the stored echo data to arrange the echo data into an arrangement sequence received by the ultrasonic probe, then calculating and reconstructing to obtain each tomogram, then arranging each tomogram in sequence to carry out three-dimensional reconstruction, and finally carrying out logarithmic compression and color or gray mapping to obtain a three-dimensional imaging graph; the fault map is any one of a reflection reconstruction fault map, a sound velocity reconstruction fault map and an attenuation coefficient reconstruction fault map.

As a further preferred embodiment of the present invention, the spiral ultrasonic tomography apparatus further includes a bed body, which is used for bearing the object to be measured and is preferably capable of providing water as an ultrasonic coupling agent medium between the ultrasonic probe and the object to be measured.

As a further preferred embodiment of the present invention, the spiral ultrasonic tomography apparatus further comprises a water treatment subsystem for filtering impurities in the water as the ultrasonic couplant medium, removing air bubbles in the water, and controlling water circulation.

Compared with the prior art, the spiral tomography method and the spiral tomography system have the advantages that the transmitting array elements sequentially transmit in a spiral track or an approximate spiral track (the spiral track can be a spiral line with fixed screw pitch, for example, the approximate spiral track can be a curve formed by parts of a plurality of spiral lines, for example), and receive echo data. The scanning process is continuous and uninterrupted, and the acquired echo data cover the whole three-dimensional space, so that the resolution and the contrast in the Z-axis direction are greatly improved, the ultrasonic tomography imaging quality is improved, meanwhile, the scanning time is shortened, artifacts are reduced, the comfort level of a patient is improved, and the popularization and the application of equipment are facilitated.

In the invention, the ultrasonic probe is used for generating ultrasonic waves, and after the ultrasonic waves interact with an object to be imaged in a reflection, transmission and the like, the ultrasonic probe can also be used for receiving the acted echo. Similar to conventional ultrasonic detection, after ultrasonic wave is transmitted by excitation each time, the acquisition system starts to receive echo after short delay, records enough signal length, and transmits echo data to the calculation server after encoding; and the server decodes the multilayer echo data and rearranges the data according to the transmission sequence of the actual physical array elements. The invention can further calculate the position of the array element in the space at each transmitting moment according to the probe motion speed and the array element transmitting time interval, complete the accurate modeling of a coordinate system, and realize the spiral track ultrasonic fault reconstruction process by referring to the reconstruction method of the two-dimensional ultrasonic image. In addition, the post-processing of the subsequent data can be performed asynchronously, so that the time for applying an ultrasonic detection process to the object to be detected can be reduced; after the scanning is finished and the echo data are stored, the stored echo data can be independently subjected to data post-processing.

Drawings

Fig. 1A is a schematic diagram of a motion trajectory of a transmitting array element in a first embodiment of the present invention.

Fig. 1B is a schematic diagram of another motion trajectory of a transmitting array element in the first embodiment of the present invention.

Fig. 2 is a plan view of a spiral track according to a first embodiment of the present invention.

Fig. 3 is a flowchart of a spiral trajectory ultrasonic tomography method in an embodiment of the present invention.

Fig. 4 is a system composition diagram of a spiral trajectory imaging system according to a second embodiment of the present invention.

Fig. 5 is a schematic diagram of system signals and data flow according to a second embodiment of the present invention.

Fig. 6A is a reconstructed thigh slice in a second embodiment of the invention.

Fig. 6B is a three-dimensional perspective view of a reconstructed thigh according to a second embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The ultrasonic tomography method based on the spiral track scanning mode can be carried out according to the following steps during specific operation:

s1: acquiring external input information, and setting scanning parameters including a screw pitch, an emission mode, a coding mode, a scanning layer number and the like;

the acquisition of the spiral track of the transmitting array element, taking the probe as a ring probe as an example, can adopt any one of the following 3 ways:

i. the transmitting array element is not changed, and the whole probe is translated along the Z axis on one hand, and simultaneously rotates around the Z axis according to the preset fixed hour-hand direction; for example, when the fixed hour hand direction is preset to be counterclockwise, the whole probe is translated along the Z axis on one hand, and simultaneously rotates counterclockwise around the Z axis on the other hand; the same principle is carried out in the clockwise direction;

the transmitting array element is not changed, the whole probe is translated along the Z axis on one hand, and simultaneously rotated around the Z axis in a mode of changing clockwise-anticlockwise hour-hand period, and the clockwise direction of one rotation is changed when one screw pitch is reached; for example, the probe as a whole translates along the Z-axis, while simultaneously rotating around the Z-axis in the clockwise direction in a clockwise direction, followed by a counterclockwise direction, followed by a clockwise direction, followed by a counterclockwise direction.

The probe only translates along the Z axis, and the transmitting array elements are circularly switched according to a preset fixed clockwise direction (such as an anticlockwise direction) (the moving direction of the ultrasonic probe along the Z axis is recorded as the positive direction of the Z axis, the switching in the anticlockwise direction meets the right-hand rule, and the switching in the clockwise direction meets the left-hand rule);

the probe only moves along the Z axis, and the transmitting array elements are circularly switched according to the preset changing clockwise direction (such as the anticlockwise direction-the clockwise direction-the anticlockwise direction with periodic change). The frequency of array element switching can be preset, and the frequency of change in the hour hand direction can also be preset; the frequency of the array element switching may be an integer multiple of the frequency of the change in the clockwise direction.

When the mode i is adopted, the thread pitch is related to and influenced by the translation speed and the rotation angular speed; and the rotation angle alpha of each layer can only be equal to 360 degrees, and correspondingly obtained transmitting array element trajectory lines are distributed along a complete spiral line.

When the mode ii is adopted, the thread pitch is related to the magnitude of the translational velocity and the magnitude of the rotational angular velocity and is simultaneously influenced by the magnitude of the translational velocity and the magnitude of the rotational angular velocity; the rotation angle alpha of each layer can be equal to 360 degrees or less than 360 degrees, and correspondingly obtained transmitting array element track lines are formed by combining a plurality of sections of spiral lines.

When the modes iii and iv are adopted, the thread pitch is related to the translation speed and the array element switching frequency and is simultaneously influenced by the translation speed and the array element switching frequency; and at this moment, the rotation angle α of each layer may be equal to 360 degrees or less than 360 degrees, and the corresponding obtained transmitting array element trajectory lines are distributed along a complete spiral line or along a part of the spiral line.

In addition, for the ultrasonic probe, the ultrasonic wave may be sequentially excited and transmitted at equal time intervals, or partial array elements in the probe may be selected in advance to be sequentially excited and transmitted, that is, the ultrasonic wave is sequentially excited and transmitted according to the partial array elements selected in advance.

S2: the industrial personal computer sends an excitation acquisition instruction, and an excitation acquisition system starts to emit ultrasonic waves and receives echo data;

s3: the storage and calculation server receives the original data transmitted by the acquisition system and stores the original data to be subsequently processed;

s4: the server rearranges and decodes the received original data to arrange the echo data into an arrangement sequence received by the physical probe, and reconstructs a fault map by using a reconstruction algorithm, wherein the fault map comprises a reflection map, a sound velocity map and an attenuation map;

s5: and (3) performing post-processing such as contrast enhancement on the tomogram, mapping and visualizing the tomogram according to a pre-stored color table, and finally performing three-dimensional reconstruction and display.

Correspondingly, the ultrasonic tomography system based on the spiral track scanning mode in the invention can comprise an ultrasonic probe, a motion control subsystem, an excitation acquisition subsystem and a calculation server, wherein:

the ultrasonic probe is used for generating ultrasonic waves, and after the ultrasonic waves interact with an object to be imaged in a reflection mode, a transmission mode and the like, the ultrasonic probe can also be used for receiving echoes after the interaction;

the motion control subsystem is used for controlling the probe to move along the Z-axis direction in a uniform speed mode, so that three-dimensional ultrasonic echo information of an object to be imaged is continuously acquired;

the excitation acquisition subsystem is used for generating a high-voltage excitation signal to drive the probe to generate ultrasonic waves, and the acquisition subsystem is used for collecting echo signals, digitizing and transmitting the echo signals to the server;

the computing server can be used for receiving the echo data packet sent by the acquisition system, decoding and rearranging the data format, then reconstructing the ultrasonic tomogram by using an algorithm, and finally reconstructing a three-dimensional stereogram by using the multilayer tomogram.

The ultrasonic probe can be sequentially excited to transmit ultrasonic waves at equal time intervals, and the ultrasonic probe is driven to translate along the Z axis by matching with the motion control subsystem, so that the motion trail of the transmitting array element is spiral or approximately spiral; after each excitation, the acquisition system starts to receive the echo after a short delay, records enough signal length, and transmits the encoded echo data to the calculation server; the server decodes the multilayer echo data and rearranges the data according to the transmitting sequence of the actual physical array elements; and calculating the position of the array element in the space at each transmitting moment according to the probe motion speed and the array element transmitting time interval, finishing accurate modeling of a coordinate system, and realizing the spiral track ultrasonic fault reconstruction process by referring to a reconstruction method of a two-dimensional ultrasonic image.

Besides the above components, the ultrasonic tomography system based on the spiral track scanning mode can additionally be provided with other matched components, such as a bed body, a water treatment subsystem and an industrial control computer, wherein:

the bed body is used for bearing each component of the system and also used for bearing a scanning object; because a certain distance exists between the probe and an object to be scanned, an aqueous medium is required to be used as an ultrasonic couplant, and the water treatment system is used for filtering impurities in the couplant water, removing bubbles in the water and controlling water circulation; the industrial control computer can be used as a control center of the whole system and can be simultaneously used as a human-computer interaction interface to undertake the tasks of controlling and coordinating all the components.