Ultrasonic imaging method and device

Abstract

This application discloses an ultrasonic imaging method and apparatus. The method comprises: utilizing an external magnetic field to concentrate a magnetic ultrasonic contrast agent in a target area; emitting ultrasonic waves to the target area to activate the magnetic ultrasonic contrast agent, causing it to scintillate; detecting ultrasonic echoes from the target area; and generating an ultrasonic image of the target area using the ultrasonic echo signals. The above technical solution utilizes an external magnetic field to concentrate the magnetic ultrasonic contrast agent in the target area, thereby reducing the mechanical index of the ultrasonic wave used in ultrasonic scintillation imaging.

Description

Technical Field

[0001] The present application relates to the field of ultrasonic imaging, and in particular to an ultrasonic imaging method and device. Background Art

[0002] In order to enhance the imaging effect of ultrasound images, ultrasound contrast agents are generally used. As a new type of ultrasound contrast agent, droplet-based ultrasound contrast agents (such as nanodroplets) are widely used.

[0003] Droplet-based ultrasound contrast agents can be imaged using scintigraphy. To achieve scintigraphy, ultrasound waves with high pressures are required to activate the scintillation of the droplets. However, using high pressures can result in an ultrasound mechanical index that exceeds the specified safety range. Summary of the Invention

[0004] The present application provides an ultrasonic imaging method and device, which can realize ultrasonic scintigraphy while reducing the mechanical index.

[0005] In a first aspect, an ultrasound imaging method is provided, comprising: utilizing an external magnetic field to gather a magnetic ultrasound contrast agent in a target area; emitting ultrasound waves to the target area to activate the magnetic ultrasound contrast agent so that the magnetic ultrasound contrast agent exhibits a flickering phenomenon; detecting an ultrasound echo of the target area; and generating an ultrasound image of the target area using the ultrasound echo signal.

[0006] In a possible implementation, the magnetic field strength of the target area is greater than or equal to 4800 Gs.

[0007] In a possible implementation, the mechanical index of the ultrasound wave is less than 1.9.

[0008] In a possible implementation, the time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave is greater than or equal to 5 ms.

[0009] In one possible implementation, generating an ultrasonic image of the target area using the ultrasonic echo signal includes: obtaining an imaging sequence of the target area using the ultrasonic echo signal; and performing autocorrelation processing on adjacent images in the imaging sequence using an autocorrelation algorithm to generate the ultrasonic image.

[0010] In a possible implementation, the ultrasound image is generated based on 2-20 consecutive frames in the imaging sequence.

[0011] In a possible implementation, the magnetic ultrasound contrast agent is a magnetic nanodroplet.

[0012] In a second aspect, an ultrasonic imaging device is provided, comprising: a magnetic targeting module for concentrating a magnetic ultrasonic contrast agent in a target area; an ultrasonic transmitting module for transmitting ultrasonic waves to the target area to activate the magnetic ultrasonic contrast agent so that the magnetic ultrasonic contrast agent exhibits a flickering phenomenon; an ultrasonic detection module for detecting an ultrasonic echo of the target area; and an ultrasonic image generation module for generating an ultrasonic image of the target area using the ultrasonic echo signal.

[0013] In a possible implementation, the magnetic field strength of the target area is greater than or equal to 4800 Gs.

[0014] In a possible implementation, the mechanical index of the ultrasound wave is less than 1.9.

[0015] In a possible implementation, the time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave is greater than or equal to 5 ms.

[0016] In a possible implementation, the ultrasound image generation module is configured to: obtain an imaging sequence of the target area using the ultrasound echo signal; and perform autocorrelation processing on adjacent images in the imaging sequence using an autocorrelation algorithm to generate the ultrasound image.

[0017] In a possible implementation, the ultrasound image is generated based on 2-20 consecutive frames in the imaging sequence.

[0018] In a possible implementation, the magnetic ultrasound contrast agent is a magnetic nanodroplet.

[0019] In the related art, the ultrasonic contrast agent is in a flowing state (e.g., the ultrasonic contrast agent will flow with the blood). The embodiment of the present application utilizes an external magnetic field to gather the magnetic ultrasonic contrast agent in the target area, so that the energy of the ultrasonic wave can be accumulated by the ultrasonic contrast agent in the target area. Since the ultrasonic contrast agent in the target area can accumulate the energy of the ultrasonic wave, even if the sound pressure of the ultrasonic wave emitted toward the target area is lower, it is possible to activate the scintillation phenomenon of the ultrasonic contrast agent. It can be seen that the embodiment of the present application makes it possible to achieve ultrasonic scintillation imaging under the premise of reducing the mechanical index. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flowchart of an ultrasonic imaging method provided in an embodiment of the present application.

[0021] Figure 2 It is a flowchart of another ultrasonic imaging method provided in an embodiment of the present application.

[0022] Figure 3It is a structural schematic diagram of an ultrasonic imaging device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] For ease of understanding, first combine Figure 1 The general process of ultrasound imaging is introduced.

[0024] Step S12: sending ultrasonic waves to the target area.

[0025] The ultrasonic wave can be generated by an ultrasonic wave transmitting module. The ultrasonic wave transmitting module may include, for example, a driving circuit, an oscillator, and other components. The target area mentioned herein may be the area to be ultrasonically imaged. The target area may be, for example, a tissue portion of a human or animal body, such as the human lungs or the animal liver.

[0026] Step S13: detecting the ultrasonic echo of the target area.

[0027] The ultrasonic echo of the above-mentioned ultrasonic wave can be detected and / or received. The ultrasonic echo may include a reflection signal formed by the target area reflecting the above-mentioned ultrasonic wave. The ultrasonic echo may refer to an acoustic signal or an electrical signal corresponding to the acoustic signal. The ultrasonic echo can be detected and / or received by an ultrasonic echo detection module. The ultrasonic echo detection module may, for example, include a conversion device that converts the acoustic wave into an electrical signal. The conversion device may, for example, include one or more of a piezoelectric ceramic and an AD module. Taking the ultrasonic echo as an electrical signal as an example, in some embodiments, the electrical signal can be stored in a storage medium (or a real-time storage medium) for subsequent operations.

[0028] Step S14: Generate an ultrasonic image of the target area using the ultrasonic echo signal.

[0029] The ultrasound image may be generated, for example, by an ultrasound signal reconstruction module, which may perform one or more of the following processes on the ultrasound echo (or the electrical signal corresponding to the ultrasound echo) to obtain the ultrasound image: beamforming, filtering, and frame processing.

[0030] The above describes the general process of ultrasound imaging. To enhance ultrasound images, ultrasound contrast imaging (CEU) is often used. This technology offers advantages such as fast imaging speed, low cost, and high image quality. Consequently, ultrasound imaging has become an indispensable imaging modality in both clinical and basic research.

[0031] Ultrasound contrast imaging requires the use of ultrasound contrast agents. There are many types of ultrasound contrast agents, including microbubble-based and droplet-based ones.

[0032] Microbubble-based ultrasound contrast agents contain air bubbles. These bubbles effectively reflect ultrasound waves, enhancing imaging. However, microbubble-based ultrasound contrast agents are large and cannot easily penetrate the spaces between vascular endothelial cells. Therefore, microbubble-based ultrasound contrast agents have difficulty penetrating deep into tissues (such as targeted tissues like tumors).

[0033] The size of droplet-based ultrasound contrast agents can be made relatively small. In some embodiments, droplet-based ultrasound contrast agents can be made nanometer-sized. Therefore, the ultrasound contrast agent is sometimes also referred to as nanodroplets. The size of nanodroplets can be, for example, less than 800 nm. Droplet-based contrast agents (especially nanodroplets) can easily penetrate the gaps between vascular endothelial cells, thereby penetrating deep into tissues (such as targeted tissues such as tumors). Therefore, droplet-based contrast agents, as a new generation of ultrasound contrast agents, have gradually been widely used in ultrasound contrast imaging or drug delivery.

[0034] Droplet-based ultrasound contrast agents have a liquid core. Using the same imaging method as microbubble-based ultrasound contrast agents for this type of ultrasound contrast agent results in poor imaging. This is because the bubbles within microbubble-based ultrasound contrast agents generate strong ultrasonic echoes, ensuring the display of ultrasound images. However, under ultrasound waves of the same sound pressure, ultrasound contrast agents with liquid cores produce weaker ultrasonic echoes, resulting in hypoechoic conditions, which significantly reduces the effectiveness of ultrasound contrast agents.

[0035] To enhance the imaging effect of droplet-based ultrasound contrast agents, scintigraphy has been introduced. Scintigraphy involves using high-pressure ultrasound (e.g., a mechanical index of 2-5) to activate the droplet-based ultrasound contrast agent, causing the core of the droplet-based ultrasound contrast agent to transition from a liquid to a gaseous state. The gaseous core then reflects the ultrasound, generating a strong ultrasound echo. This strong ultrasound echo is then used to enhance imaging.

[0036] The following describes the reason why the mechanical index of ultrasound waves in ultrasound scintigraphy is relatively high, taking a section of a human arm as a target area for ultrasound scintigraphy.

[0037] Before performing ultrasonic scintigraphy on the target area, a droplet-based ultrasound contrast agent is pre-injected into the arm's blood vessels. At this point, the droplet-based ultrasound contrast agent flows into the target area along with the blood flow in the arm's blood vessels. An ultrasonic transmitter then transmits ultrasound waves of relatively high sound pressure to the target area, activating the droplet-based ultrasound contrast agent that has flowed into the target area. The activated ultrasound contrast agent can generate a strong ultrasound echo, thereby ensuring enhanced imaging. If the droplet-based ultrasound contrast agent that has flowed into the target area is not activated after the ultrasonic transmitter transmits a frame of ultrasound waves to the target area, when the ultrasonic transmitter transmits ultrasound waves to the target area again, the droplet-based ultrasound contrast agent that has flowed into the target area will flow out of the target area, causing the droplet-based ultrasound contrast agent that has flowed into the target area to remain unable to be activated, and scintigraphy cannot be achieved. In other words, to ensure that droplet-based ultrasound contrast agents can be instantly activated by ultrasound, the ultrasound pressure is generally set relatively high (i.e., the ultrasound mechanical index is relatively high), resulting in a mechanical index exceeding the safety range specified by the US Food and Drug Administration (FDA). Therefore, how to achieve ultrasound scintigraphy while maintaining a low mechanical index is an urgent problem to be solved.

[0038] Based on the above issues, an embodiment of the present application proposes an ultrasound imaging method that utilizes an external magnetic field to concentrate a magnetic ultrasound contrast agent in a target area. An ultrasound transmitter can then continuously emit low-mechanical-index ultrasound waves to the magnetic ultrasound contrast agent concentrated in the target area. The accumulated low-mechanical-index ultrasound waves then activate the magnetic ultrasound contrast agent in the target area, causing the magnetic ultrasound contrast agent to scintillate. In this way, the technical solution of the present application can achieve the technical effect of reducing the mechanical index of ultrasound waves used in ultrasound scintillation imaging.

[0039] Figure 2 This is a flow chart of another ultrasonic imaging method provided in an embodiment of the present application. Figure 2 Steps S22-S24 of the imaging method 20 are the same as Figure 1 Therefore, for the parts of the imaging method 20 not described in detail, reference can be made to the above embodiment of the imaging method 10.

[0040] The following describes steps S21 to S24 of the imaging method 20 .

[0041] Step S21 : Using an external magnetic field to gather the magnetic ultrasound contrast agent in the target area.

[0042] The external magnetic field can be generated by a magnet, which can be, for example, a permanent magnet or an electromagnet. The external magnetic field can be, for example, one or more gradient magnetic fields, which are not specifically limited in this application. The magnetic ultrasonic contrast agent can be a magnetic substance that responds to ultrasonic signals, for example, the magnetic ultrasonic contrast agent can be a magnetic droplet or a magnetic nanodroplet. The magnetic ultrasonic contrast agent can be aggregated to the target area by the magnetic field of the target area. This aggregation can also be called enrichment. The magnetic field strength of the target area can be greater than or equal to 4800 Gs, thereby ensuring the aggregation effect of the magnetic ultrasonic contrast agent.

[0043] Step S22: emitting ultrasonic waves to the target area to activate the magnetic ultrasonic contrast agent, so that the magnetic ultrasonic contrast agent exhibits a scintillation phenomenon.

[0044] The embodiments of the present application do not specifically limit the mechanical index of ultrasound. As an example, the mechanical index of ultrasound can be less than 5. As another example, the mechanical index of ultrasound can be less than 1.9. Thus, the mechanical index can be ensured to be within the safety range specified by the FDA while activating the ultrasound contrast agent.

[0045] Step S23: detecting ultrasonic echoes in the target area.

[0046] The embodiments of the present application do not impose any specific limitation on the detection time of the ultrasonic echo. As an example, the time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave may be greater than or equal to 5 ms. Thus, the detection quality of the ultrasonic echo signal can be guaranteed, and the quality of ultrasonic imaging can be further guaranteed.

[0047] Step S24: Generate an ultrasonic image of the target area using the ultrasonic echo signal.

[0048] The embodiments of the present application do not specifically limit the method for generating an ultrasonic image. As an example, an ultrasonic image of a target area can be generated based on each frame of detected ultrasonic echo signals. As another example, an imaging sequence of the target area can be obtained using the detected ultrasonic echo signals, and then an autocorrelation algorithm can be used to perform autocorrelation processing on adjacent images in the imaging sequence, and finally an ultrasonic image can be generated based on the autocorrelation processing results.

[0049] The embodiment of the present application does not specifically limit the type of the autocorrelation algorithm. As an example, the autocorrelation algorithm may be an inter-frame difference method.

[0050] As an example and not a limitation, in the embodiment of the present application, 2-20 consecutive frames in the imaging sequence may be processed using an autocorrelation algorithm to generate an ultrasound image, thereby ensuring the imaging quality of the ultrasound image.

[0051] In some embodiments, steps S21 - S24 may be used to perform real-time cyclic imaging to obtain continuous ultrasound images.

[0052] Combined with the above Figure 1 and Figure 2 The method embodiment of the present application is described in detail. Figure 3 The device embodiment of the present application is described in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so for parts not described in detail, reference can be made to the previous method embodiment.

[0053] Figure 3 It is a structural schematic diagram of an ultrasonic imaging device provided in an embodiment of the present application. Figure 3 The ultrasonic imaging device 30 shown in FIG may include a magnetic targeting module 31, an ultrasonic transmitting module 32, an ultrasonic detecting module 33, and an ultrasonic image generating module 34. These modules are described in detail below.

[0054] The magnetic targeting module 31 can be used to concentrate the magnetic ultrasound contrast agent in a target area.

[0055] The ultrasound transmitting module 32 can be used to transmit ultrasound to the target area to activate the magnetic ultrasound contrast agent, causing the magnetic ultrasound contrast agent to exhibit a scintillation phenomenon.

[0056] The ultrasonic detection module 33 may be used to detect ultrasonic echoes of a target area.

[0057] The ultrasound image generation module 34 may be configured to generate an ultrasound image of the target area using the ultrasound echo signal.

[0058] Optionally, the magnetic field strength of the target area is greater than or equal to 4800 Gs.

[0059] Optionally, the mechanical index of the ultrasound is <1.9.

[0060] Optionally, the time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave is greater than or equal to 5 ms.

[0061] Optionally, the ultrasound image generation module is configured to: obtain an imaging sequence of the target area using ultrasound echo signals; and perform autocorrelation processing on adjacent images in the imaging sequence using an autocorrelation algorithm to generate an ultrasound image.

[0062] Optionally, the ultrasound image is generated based on 2-20 consecutive frames in an imaging sequence.

[0063] Optionally, the magnetic ultrasound contrast agent is a magnetic nanodroplet.

[0064] This application achieves ultrasound scintigraphy at a low mechanical index by focusing a magnetic ultrasound contrast agent on the target area to be imaged through an external magnetic field. This reduces the biothermal effect caused by a high mechanical index and further avoids damage to biological tissue. Furthermore, the low mechanical index scintigraphy method described in this application also provides new insights into in vivo ultrasound super-resolution.

[0065] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An ultrasonic imaging method, characterized in that: The method comprises: Using an external magnetic field to focus magnetic ultrasound contrast agents in the target area; emitting ultrasonic waves to the target area to activate the magnetic ultrasonic contrast agent, so that the magnetic ultrasonic contrast agent exhibits a scintillation phenomenon; detecting an ultrasonic echo of the target area; generating an ultrasonic image of the target area using the ultrasonic echo signal; The magnetic ultrasound contrast agent is a magnetic nanodroplet, the mechanical index of the ultrasound wave is less than 1.9, the ultrasound echo is the echo of the ultrasound wave, and the target area is a tissue area in a human or animal body.

2. The method according to claim 1, characterized in that The magnetic field strength of the target area is greater than or equal to 4800 Gs.

3. The method according to claim 1, characterized in that The time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave is greater than or equal to 5 ms.

4. The method according to claim 1, wherein The step of generating an ultrasonic image of the target area by using the ultrasonic echo signal includes: obtaining an imaging sequence of the target area using the ultrasonic echo signal; An autocorrelation algorithm is used to perform autocorrelation processing on adjacent images in the imaging sequence to generate the ultrasound image.

5. The method according to claim 4, characterized in that The ultrasound image is generated based on 2-20 consecutive frames in the imaging sequence.

6. An ultrasonic imaging device, characterized in that: include: a magnetic targeting module for concentrating a magnetic ultrasound contrast agent in a target area; an ultrasonic transmitting module, configured to transmit ultrasonic waves to the target area to activate the magnetic ultrasonic contrast agent, causing the magnetic ultrasonic contrast agent to exhibit a scintillation phenomenon; an ultrasonic detection module, configured to detect ultrasonic echoes of the target area; an ultrasonic image generating module, configured to generate an ultrasonic image of the target area using the ultrasonic echo signal; The magnetic ultrasound contrast agent is a magnetic nanodroplet, the mechanical index of the ultrasound wave is less than 1.9, the ultrasound echo is the echo of the ultrasound wave, and the target area is a tissue area in a human or animal body.

7. The device according to claim 6, characterized in that The magnetic field strength of the target area is greater than or equal to 4800 Gs.

8. The device according to claim 6, characterized in that The time interval between the detection time of the ultrasonic echo and the emission time of the ultrasonic wave is greater than or equal to 5 ms.

9. The device according to claim 6, characterized in that The ultrasound image generation module is used for: obtaining an imaging sequence of the target area using the ultrasonic echo signal; An autocorrelation algorithm is used to perform autocorrelation processing on adjacent images in the imaging sequence to generate the ultrasound image.

10. The device according to claim 9, characterized in that The ultrasound image is generated based on 2-20 consecutive frames in the imaging sequence.

Images