Photoacoustic imaging method and photoacoustic imaging system

Abstract

The invention discloses a photoacoustic imaging method and a photoacoustic imaging system, and the method comprises the steps: obtaining the ultrasonic image data of an imaging target, and determining the biological tissue type of the imaging target based on the features of the ultrasonic image data; a luminous flux distribution result corresponding to the biological tissue type is determined, and the luminous flux distribution result is generated after a simulation target tissue corresponding to the biological tissue type of the imaging target is irradiated by laser in the simulation imaging process of the simulation target tissue; the light source is used for representing luminous flux distribution conditions of biological tissues relative to the body surface under different imaging depths; obtaining photoacoustic image data of the imaging target; determining compensation parameters of the photoacoustic image data based on the luminous flux distribution result; compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data; and generating a photoacoustic image according to the compensated photoacoustic image data. According to the invention, the quality and precision of the photoacoustic image can be improved.

Description

Technical Field

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

[0002] Photoacoustic imaging combines the high contrast of optical imaging and the high resolution of ultrasound imaging, and is a new type of biomedical imaging method. Its principle is to use the thermal expansion of biological tissues caused by laser irradiation in the photoacoustic effect, receive the acoustic signal generated by mechanical vibration through the ultrasonic transducer, and reflect the optical absorption characteristics of biological tissues by reconstructing the initial sound pressure field. According to the system structure characteristics of photoacoustic imaging, photoacoustic imaging can be roughly divided into three categories: photoacoustic tomography (PAT), photoacoustic microscopy (PAM) and photoacoustic endoscopy (PAE). Among them, the PAT system can be applied to large-scale biological imaging, has a large field of view and high penetration depth, and is the imaging mode with the most clinical transformation potential among the existing photoacoustic imaging modes.

[0003] In photoacoustic imaging, it is often simplified by assuming that the incident light is evenly distributed on the surface and inside of the tissue and that the energy does not decay with depth. In fact, most biological tissues are turbid media with high scattering and opaque characteristics. When the laser is transmitted in the tissue, it is both absorbed and scattered. The absorption and scattering of the laser and the distribution of the light flux by tissue structures of different components are all uneven. In addition, as the incident depth of the laser in the tissue continues to increase, the penetration ability of the laser is weakened, the distribution of the light energy is dispersed, and the light flux is significantly reduced. These factors will not only reduce the accuracy and imaging depth of the photoacoustic image, but also cause deviations in the calculation results of blood oxygen saturation. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] An embodiment of the present invention provides a photoacoustic imaging method, the method comprising:

[0006] Acquiring ultrasound image data of an imaging target, and determining a biological tissue type of the imaging target based on features of the ultrasound image data;

[0007] Determine a light flux distribution result corresponding to the biological tissue type, wherein the light flux distribution result is generated after laser irradiation of the simulated target tissue during simulated imaging of the simulated target tissue corresponding to the biological tissue type of the imaging target, and the light flux distribution result is used to characterize the light flux distribution of the biological tissue type relative to the body surface at different imaging depths;

[0008] Acquiring photoacoustic image data of the imaging target corresponding to the ultrasound image data, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process;

[0009] determining a compensation parameter of the photoacoustic image data based on the light flux distribution result;

[0010] Compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data;

[0011] A photoacoustic image is generated according to the compensated photoacoustic image data.

[0012] In one embodiment, determining the light flux distribution result corresponding to the biological tissue type of the imaging target includes:

[0013] Retrieving the light flux distribution result corresponding to the biological tissue type stored in advance from a database, wherein the light flux distribution result is obtained by performing simulated imaging on a simulated target tissue corresponding to the biological tissue type of the imaging target in advance;

[0014] Alternatively, simulated imaging is performed on a simulated target tissue corresponding to the biological tissue type of the imaging target in real time to obtain the light flux distribution result.

[0015] In one embodiment, performing simulated imaging on a simulated target tissue corresponding to the biological tissue type of the imaging target to obtain the light flux distribution result includes:

[0016] Establishing a simulated target tissue corresponding to the biological tissue type, and constructing a simulated laser light source above the simulated target tissue to simulate laser irradiation of the simulated target tissue;

[0017] Obtaining constraint conditions of propagation characteristics of the laser in the simulated target tissue;

[0018] The constraint condition is solved to obtain the light flux distribution result incident on the simulation target tissue.

[0019] In one embodiment, determining the light flux distribution result corresponding to the biological tissue type includes:

[0020] Providing at least two options of alternative luminous flux distribution results on the display interface;

[0021] A selection instruction for the option is received, and a light flux distribution result corresponding to the biological tissue type is determined from among the candidate light flux distribution results according to the selection instruction.

[0022] In one embodiment, the light flux distribution result includes a two-dimensional light flux distribution result of the simulated target tissue at different imaging depths relative to the body surface.

[0023] In one embodiment, the light flux distribution result includes a one-dimensional distribution result of the light flux of the simulated target tissue at different imaging depths relative to the body surface.

[0024] In one embodiment, the one-dimensional distribution result of the light flux includes the one-dimensional distribution result of the light flux at the center position of the simulated imaging section in the simulated target tissue at different imaging depths.

[0025] In one embodiment, compensating the photoacoustic image data based on the compensation parameter includes: compensating the photoacoustic intensity signals at different imaging depths based on the compensation parameter.

[0026] In one embodiment, the acquiring the photoacoustic image data of the imaging target corresponding to the ultrasound image data comprises: acquiring first photoacoustic image data of the imaging target corresponding to the ultrasound image data at a first wavelength;

[0027] The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the first photoacoustic image data based on the compensation parameter to obtain compensated first photoacoustic image data.

[0028] In one embodiment, the acquiring of the photoacoustic image data of the imaging target corresponding to the ultrasound image data further includes:

[0029] Acquire second photoacoustic image data of the imaging target corresponding to the ultrasound image data at a second wavelength, where the second wavelength is different from the first wavelength;

[0030] The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the second photoacoustic image data based on the compensation parameter to obtain compensated second photoacoustic image data;

[0031] Generating a photoacoustic image according to the compensated photoacoustic image data includes: performing blood oxygen reconstruction on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

[0032] In one embodiment, the light flux distribution result includes a first light flux distribution result corresponding to the first wavelength and a second light flux distribution result corresponding to the second wavelength, and the compensation parameter includes a first compensation parameter determined based on the first light flux distribution result and a second compensation parameter determined based on the second light flux distribution result;

[0033] The compensating the photoacoustic image data according to the compensation parameter includes: compensating the first photoacoustic image data according to the first compensation parameter, and compensating the second photoacoustic image data according to the second compensation parameter.

[0034] Another aspect of the present invention provides a photoacoustic imaging method, the method comprising:

[0035] Acquiring ultrasound image data of an imaging target, and determining a biological tissue type of the imaging target based on features of the ultrasound image data;

[0036] Acquiring photoacoustic image data of the imaging target corresponding to the ultrasound image data, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process;

[0037] determining a compensation parameter of the photoacoustic image data based on the biological tissue type;

[0038] Compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data;

[0039] A photoacoustic image is generated according to the compensated photoacoustic image data.

[0040] In one embodiment, the acquiring the photoacoustic image data of the imaging target corresponding to the ultrasound image data comprises: acquiring first photoacoustic image data of the imaging target corresponding to the ultrasound image data at a first wavelength;

[0041] The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the first photoacoustic image data based on the compensation parameter to obtain compensated first photoacoustic image data.

[0042] In one embodiment, the acquiring of the photoacoustic image data of the imaging target corresponding to the ultrasound image data further includes:

[0043] Acquire second photoacoustic image data of the imaging target corresponding to the ultrasound image data at a second wavelength, where the second wavelength is different from the first wavelength;

[0044] The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the second photoacoustic image data based on the compensation parameter to obtain compensated second photoacoustic image data;

[0045] Generating a photoacoustic image according to the compensated photoacoustic image data includes: performing blood oxygen reconstruction on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

[0046] Another aspect of the present invention provides a photoacoustic imaging system, the photoacoustic imaging system comprising:

[0047] Photoacoustic probe;

[0048] A laser, used for emitting laser light to an imaging target, so that the imaging target returns a photoacoustic signal;

[0049] A receiving circuit, used for controlling the photoacoustic probe to receive the photoacoustic signal;

[0050] A processor, configured to execute the photoacoustic imaging method as described above, so as to generate a photoacoustic image based on the photoacoustic signal;

[0051] A display is used to display the photoacoustic image.

[0052] The photoacoustic imaging method and the photoacoustic imaging system of the embodiments of the present invention compensate the photoacoustic image data in a targeted manner according to the light flux distribution result corresponding to the biological tissue type of the imaging target, thereby achieving the effect of enhancing the intensity of the photoacoustic signal and improving the imaging depth, and optimizing the quality and accuracy of the photoacoustic image. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0054] Figure 1 A structural block diagram of a photoacoustic imaging system according to an embodiment of the present invention is shown;

[0055] Figure 2 A schematic flow chart showing a photoacoustic imaging method according to an embodiment of the present invention;

[0056] Figure 3 A schematic diagram showing an ultrasound image according to an embodiment of the present invention;

[0057] Figure 4 A schematic diagram showing simulation imaging of a simulation target tissue corresponding to biological tissue information of an imaging target according to an embodiment of the present invention;

[0058] Figure 5 A schematic diagram showing a simulated photoacoustic imaging section of a simulated target tissue according to an embodiment of the present invention;

[0059] Figure 6 A schematic diagram showing a two-dimensional distribution result of light flux according to an embodiment of the present invention;

[0060] Figure 7 A schematic diagram showing a one-dimensional distribution result of luminous flux according to an embodiment of the present invention;

[0061] Figure 8 A schematic flow chart of a photoacoustic imaging method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0063] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0064] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0065] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0066] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0067] Next, first refer to Figure 1 A photoacoustic imaging system according to an embodiment of the present invention is described. Figure 1 FIG. 1 is a schematic structural block diagram of a photoacoustic imaging system 100 according to an embodiment of the present invention.

[0068] like Figure 1 As shown, the photoacoustic imaging system 100 includes a laser 110, a photoacoustic probe 112, a transmitting circuit 114, a receiving circuit 116, a processor 118, and a display 120. Further, the photoacoustic imaging system may also include a transmitting / receiving selection switch 122 and a beamforming module 124, and the transmitting circuit 114 and the receiving circuit 116 may be connected to the photoacoustic probe 112 through the transmitting / receiving selection switch 122.

[0069] The laser 110 is used to emit laser light to the imaging target. After emitting laser light to the imaging target, the receiving circuit 116 can receive the photoacoustic signal returned by the imaging target under the excitation of the laser light through the photoacoustic probe 112. The photoacoustic signal is directly or after being processed and sent to the processor 118, which processes the photoacoustic signal to obtain photoacoustic image data of the imaging target.

[0070] In one embodiment of the present application, the laser 110 can be connected to the transmit / receive selection switch 122, and the transmit / receive selection switch 122 controls the emission of the laser. The laser 120 can also be connected to the photoacoustic probe 112 through an optical transmission tool, and the optical fiber bundle is coupled to the photoacoustic probe 112. The optical fiber bundle is used to transmit the laser to both sides of the photoacoustic probe 110, and the imaging target is irradiated by back-lighting. In some implementations, the laser 120 and the optical fiber bundle can be coupled to the inside of the photoacoustic probe 112, wherein the photoacoustic probe 112 also includes a plurality of transducer array elements for ultrasonic imaging. In this way, the photoacoustic probe 112 can be used not only for conventional ultrasonic imaging, but also for photoacoustic imaging.

[0071] The multiple transducer array elements in the photoacoustic probe 112 are arranged in a two-dimensional array, and the multiple transducer array elements can also form a convex array. The transducer array element is used to transmit ultrasonic waves according to the excitation electrical signal, or convert the received ultrasonic waves into electrical signals, so each transducer array element can be used to realize the mutual conversion between the electrical pulse signal and the ultrasonic wave, thereby realizing the transmission of ultrasonic waves to the tissue of the imaging target, and can also be used to receive the ultrasonic wave echo reflected by the tissue.

[0072] When performing ultrasonic imaging, the transmitting sequence and receiving sequence can be used to control which transducer array elements are used to transmit ultrasonic waves and which transducer array elements are used to receive ultrasonic waves, or control the transducer array elements to transmit ultrasonic waves or receive ultrasonic echoes in time slots. The transducer array elements involved in ultrasonic emission can be excited by electrical signals at the same time, thereby simultaneously transmitting ultrasonic waves; or, the transducer array elements involved in ultrasonic beam emission can also be excited by several electrical signals with a certain time interval, thereby continuously transmitting ultrasonic waves with a certain time interval.

[0073] During the ultrasonic imaging process, the transmitting circuit 114 generates a transmitting sequence according to the control of the processor 118, and the transmitting sequence is used to control some or all of the multiple transducer array elements to transmit ultrasonic waves to the target tissue. The transmission sequence parameters include the number of transducer array element positions used for transmission and the ultrasonic beam transmission parameters, such as amplitude, frequency, number of transmissions, transmission interval, transmission angle, waveform, focal position, etc. In some cases, the transmitting circuit 114 is also used to phase delay the transmitted beam so that different transducer array elements transmit ultrasonic waves at different times so that each transmitted ultrasonic beam can be focused on a predetermined area of ​​interest. The transmission sequence parameters corresponding to different imaging modes may be different. After the ultrasonic echo signal is received by the receiving circuit 116 and processed by subsequent modules and corresponding algorithms, ultrasonic images of different imaging modes can be generated.

[0074] The receiving circuit 116 may include one or more amplifiers, analog-to-digital converters, etc. The amplifier is used to amplify the received ultrasonic echo signal or photoacoustic signal after appropriate gain compensation, and the analog-to-digital converter is used to sample the analog echo signal at a predetermined time interval to convert it into a digitized signal. The digitized echo signal still retains amplitude information, frequency information, and phase information. The receiving circuit 116 sends the ultrasonic echo signal or photoacoustic signal to the beamforming module 124 for processing.

[0075] The beamforming module 124 performs focusing delay, weighting and channel summing on the ultrasound echo signal or the photoacoustic signal, and then sends it to the processor 118. The processor 118 performs signal detection, signal enhancement, data conversion, logarithmic compression and other processing on the ultrasound echo signal or the photoacoustic signal to form an ultrasound image or a photoacoustic image. The ultrasound image or the photoacoustic image obtained by the processor 118 can be displayed on the display 120 or stored in the memory 124.

[0076] Optionally, the processor 118 may be implemented as software, hardware, firmware or any combination thereof, and may use a single or multiple application specific integrated circuits (ASICs), a single or multiple general purpose integrated circuits, a single or multiple microprocessors, a single or multiple programmable logic devices, or any combination of the aforementioned circuits and / or devices, or other suitable circuits or devices. Furthermore, the processor 118 may control other components in the photoacoustic imaging system 100 to perform the corresponding steps of the methods in various embodiments of the present specification.

[0077] The display 120 is connected to the processor 118, and the display 120 may be a touch screen, a liquid crystal display, etc.; or, the display 120 may be an independent display such as a liquid crystal display, a television, etc., which is independent of the photoacoustic imaging system 100; or, the display 120 may be a display screen of an electronic device such as a smart phone or a tablet computer, etc. The number of the display 120 may be one or more.

[0078] The display 120 can display the ultrasound image or photoacoustic image obtained by the processor 118. In addition, while displaying the ultrasound image or photoacoustic image, the display 120 can also provide the user with a graphical interface for human-computer interaction. One or more controlled objects are set on the graphical interface, and the user is provided with a human-computer interaction device to input operation instructions to control these controlled objects, thereby performing corresponding control operations. For example, an icon is displayed on the graphical interface, and the icon can be operated using the human-computer interaction device to perform a specific function, such as drawing a region of interest box on the ultrasound image.

[0079] Optionally, the photoacoustic imaging system 100 may further include other human-machine interaction devices in addition to the display 120, which are connected to the processor 118. For example, the processor 118 may be connected to the human-machine interaction device through an external input / output port, and the external input / output port may be a wireless communication module, or a wired communication module, or a combination of the two. The external input / output port may also be implemented based on USB, bus protocols such as CAN, and / or wired network protocols.

[0080] The human-computer interaction device may include an input device for detecting user input information, which may be, for example, a control instruction for ultrasonic emission / reception timing, an operation input instruction for drawing points, lines, or frames on an ultrasonic image or a photoacoustic image, or other instruction types. The input device may include a keyboard, a mouse, a scroll wheel, a trackball, a mobile input device (such as a mobile device with a touch screen, a mobile phone, etc.), a multi-function knob, etc., or a combination of multiple thereof. The human-computer interaction device may also include an output device such as a printer.

[0081] The photoacoustic imaging system 100 may further include a memory 124 for storing instructions executed by the processor, storing received ultrasound echoes or photoacoustic signals, storing ultrasound images or photoacoustic images, etc. The memory may be a flash memory card, a solid-state memory, a hard disk, etc. It may be a volatile memory and / or a non-volatile memory, a removable memory and / or a non-removable memory, etc.

[0082] It should be understood that Figure 1 The components included in the photoacoustic imaging system 100 are only exemplary, and the system may include more or fewer components, which is not limited in the present invention.

[0083] Next, we will refer to Figure 2 A photoacoustic imaging method according to an embodiment of the present invention is described. Figure 2 FIG. 2 is a schematic flow chart of a photoacoustic imaging method 200 according to an embodiment of the present invention.

[0084] like Figure 2 As shown, a photoacoustic imaging method 200 according to an embodiment of the present invention includes the following steps:

[0085] In step S210, ultrasonic image data of an imaging target is acquired, and a biological tissue type of the imaging target is determined based on features of the ultrasonic image data;

[0086] In step S220, a light flux distribution result corresponding to the biological tissue type of the imaging target is determined, wherein the light flux distribution result is generated after laser irradiation of the simulated target tissue during simulated imaging of the simulated target tissue corresponding to the biological tissue type of the imaging target, and the light flux distribution result is used to characterize the light flux distribution of the biological type at different imaging depths relative to the body surface;

[0087] In step S230, photoacoustic image data of the imaging target corresponding to the ultrasound image data is acquired, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process;

[0088] In step S240, a compensation parameter of the photoacoustic image data is determined based on the light flux distribution result;

[0089] In step S250, the photoacoustic image data is compensated based on the compensation parameter to obtain compensated photoacoustic image data;

[0090] In step S260, a photoacoustic image is generated according to the compensated photoacoustic image data.

[0091] According to the photoacoustic imaging method 200 of the embodiment of the present invention, compensation parameters are determined according to the light flux distribution results corresponding to the biological tissue type of the imaging target, and the photoacoustic image data is compensated in a targeted manner according to the compensation parameters, thereby achieving the effect of enhancing the intensity of the photoacoustic signal and improving the imaging depth, and optimizing the quality and accuracy of the photoacoustic image.

[0092] Specifically, in step S210, ultrasonic image data of the imaging target is acquired. The ultrasonic image data can be acquired from a storage medium or based on real-time ultrasonic imaging. In the real-time photoacoustic imaging process, the photoacoustic imaging system can switch between the ultrasonic imaging mode and the photoacoustic imaging mode. Before performing photoacoustic imaging, the ultrasonic imaging mode is first entered. Specifically, the tissue imaging mode (i.e., B mode) in the ultrasonic imaging can be entered. In the tissue imaging mode, the ultrasonic probe is controlled to transmit ultrasonic waves to the imaging target, and the ultrasonic echo signal is received. The ultrasonic echo signal is processed by logarithmic compression, dynamic range adjustment, digital scan conversion, etc. to obtain ultrasonic image data for reflecting the tissue morphological structure of the imaging target, i.e., tissue image data. The ultrasonic image data can be displayed on the display interface of the ultrasonic imaging system for the user to observe the tissue structure of the imaging target.

[0093] Next, the biological tissue type of the imaging target is determined based on the ultrasound image data. The biological tissue type may be an organ or part corresponding to the imaging target, for example, the biological tissue type of the imaging target may be determined to be thyroid tissue, breast tissue or other organs or parts based on the ultrasound imaging data. Alternatively, the biological tissue type may be a structural type of the imaging target, for example, the imaging target simply includes a skin layer and a uniform tissue layer, or the imaging target includes a skin layer, a muscle layer, a vascular layer, etc., or the structural type of the imaging target may be further refined. The photoacoustic imaging system may pre-set a variety of structural types of imaging targets, and determine the structural type actually corresponding to the imaging target according to the ultrasound image. The acquisition method of the biological tissue type may be automatic recognition based on machine learning, a neural network training model, etc., or it may be a user-defined structure based on the features of the ultrasound image data, and the ultrasound image data is displayed on the interface, and is manually determined by the user. In step S220, the light flux distribution result corresponding to the biological tissue type of the imaging target is determined, wherein the light flux distribution result is generated after the laser irradiates the simulated target tissue during the simulated imaging process of the simulated target tissue corresponding to the biological tissue type of the imaging target, and is used to characterize the light flux distribution of the biological tissue type relative to the body surface at different imaging depths.

[0094] Among them, the pre-stored light flux distribution result corresponding to the biological tissue type of the imaging target can be called from the database, and the light flux distribution result in the database is obtained by pre-simulating the imaging of the simulated target tissue corresponding to the biological tissue information of the imaging target. Specifically, multiple simulated target tissues can be simulated in advance, and the laser irradiation of the simulated target tissue is simulated during the simulation imaging process to obtain the light flux distribution result of each simulated target tissue, and the corresponding relationship between the light flux distribution result and the biological tissue type of the simulated target tissue is recorded. In the actual imaging process, the light flux distribution result of the simulated target tissue most similar to the biological tissue type of the imaging target is retrieved from the database for optimization of the photoacoustic image. If the optimized photoacoustic image still cannot reach the expected level, the user can also adjust the biological tissue information in a targeted manner and re-call a better light flux distribution result to optimize the photoacoustic image until the expected effect is achieved. In the photoacoustic imaging process, the light flux distribution result corresponding to the pre-stored biological tissue type is used, which can greatly save the time and space of photoacoustic image processing and improve the doctor's inspection efficiency while ensuring the quality of the photoacoustic image.

[0095] Alternatively, the simulated target tissue corresponding to the biological tissue type of the imaging target can also be simulated in real time to obtain the light flux distribution result. The real-time acquisition process can be to obtain the light flux distribution result based on the parameters of the biological tissue type, such as depth, etc., after identifying the biological tissue type. The depth here can be the default, conventional, and does not need to be measured. It is based on the doctor's prior knowledge, such as the depth of the skin, the depth of the thyroid or the breast, etc. It can also be the parameter obtained by the doctor in real time based on the data of the ultrasound image. In this case, the light flux distribution result obtained by simulation based on the tissue parameters obtained in real time may be more accurate and more targeted for individual photoacoustic images.

[0096] Thereby, the matching degree between the simulation target tissue and the imaging target is improved, and the accuracy of the light flux distribution result is further improved. For example, simulation analysis software such as COMSOL can be used to simulate the imaging of the simulation target tissue.

[0097] In the process of simulated imaging, it is necessary to construct a simulated target tissue model corresponding to the biological tissue type according to the clinical use scenario of photoacoustic imaging, and to construct a simulated laser light source above the simulated target tissue to simulate the laser irradiation of the simulated target tissue. Figure 4 Two optical fiber bundles are arranged on both sides of the photoacoustic probe, and the laser source is incident at an angle of 13° between the plane of the photoacoustic probe and the vertical direction through two optical fibers, ensuring that the two-dimensional detection surface of the photoacoustic probe and the irradiation area of ​​the optical fiber bundle maintain a coplanar mode during the imaging process.

[0098] The simulated target tissue is divided into three layers: gel pad layer, skin layer and mammary gland layer. The gel pad is a colorless, transparent, sound-conducting material with a thickness of about 4-5 mm and an absorption coefficient of μ. a and the reduced scattering coefficient μ′ s The gel pad can make the laser propagate basically in a straight line, while at the same time the sound attenuation is as low as possible. It is used clinically to better fit the imaging site and improve the quality of photoacoustic images. The skin layer is below the gel pad. When the laser enters the human tissue, the first thing it contacts is the skin. Due to the influence of the coupling matching factors between the medium layers during the light transmission process and the presence of melanin in the skin layer, the reflection and absorption of light by the skin layer is very obvious. The thickness of the skin layer is generally about 1-1.5mm, and its absorption coefficient μ a and the reduced scattering coefficient μ′ s As the skin color of different races changes, individual differences are large, and can be adjusted according to actual needs. The breast layer is the target imaging area of ​​clinical photoacoustic imaging. Its thickness exceeds the limit depth (5cm) that can be achieved by current photoacoustic imaging, and its absorption coefficient μ a and the reduced scattering coefficient μ′ sA fixed value can be used. All the above layers are considered to be homogeneous tissues.

[0099] According to the biological tissue type of the above-mentioned simulation target tissue, the following can be established: Figure 5 The three-layer simulation model of 200 mm×200 mm×154 mm shown keeps a sufficient distance between the actual photoacoustic imaging area and the boundary of the simulation model, so that the premise of the subsequent application constraint conditions is established.

[0100] Next, the constraint conditions describing the propagation characteristics of the laser in the simulated target tissue are obtained, and the solution is performed according to the biological tissue information of the simulated target tissue and the constraint conditions to obtain the light flux distribution result of the laser incident on the simulated target tissue.

[0101] Specifically, the input of the light source can be regarded as two light spots parallel to and below the surface of the simulated target tissue, with a size of 5 cm × 1 cm and a depth of d z ,in:

[0102] d z = l t ×cosα

[0103] Among them, l t is the mean free path of light propagating in the first layer of medium; cosα is the cosine value of the optical fiber incident angle after refraction.

[0104] Since the refractive indexes of gel and tissue are similar, the boundary condition between the gel pad and the skin layer can be described by the following equation:

[0105]

[0106] Where Φ(r) is the luminous flux per unit time; D = 1 / (3(μ a +μ′ s )); is the vector differential operator; n is the normal vector pointing into the tissue.

[0107] Due to the attenuation of light in tissue and sufficient boundary distance, the other boundaries of the cube model can be constrained by zero flux conditions. The radiation transmission equation can be used to describe the propagation process of light in the global model, but since its accurate analytical solution is very difficult to obtain, the scattering equation or the diffusion equation is generally used to approximate the solution in actual use. The scattering equation is used here to describe the forward model of the statistical motion law of photon density waves in highly scattering media. For homogeneous media, the photon scattering model is equivalent to the Helmholtz equation:

[0108]

[0109] in,

[0110] At the same time, the energy input of the incident light source S can be described as

[0111]

[0112] After completing the equation input in the simulation software, mesh division and calculation can be performed to obtain the following Figure 6 The two-dimensional distribution results of the light flux of the simulated target tissue at different imaging depths relative to the body surface are shown. Furthermore, the one-dimensional distribution results of the light flux of the simulated target tissue at different imaging depths relative to the body surface can also be obtained. The one-dimensional distribution results of the light flux can be the one-dimensional distribution results of the light flux at the center position of the simulated imaging section in the simulated target tissue, such as Figure 7 The one-dimensional distribution result of the light flux can also be a one-dimensional distribution result of the light flux obtained by statistically analyzing the light flux distribution data at multiple positions on the simulated imaging section. The one-dimensional distribution result of the light flux can actually be regarded as a compensation surface, because for the photoacoustic data at the same depth, the compensation parameters of the light flux are the same.

[0113] In some embodiments, the light flux distribution result corresponding to the biological tissue type may be determined in combination with user interaction. Specifically, at least two options of alternative light flux distribution results may be provided on the display interface, a selection instruction for the above options may be received, and the light flux distribution result corresponding to the actual biological tissue type of the imaging target may be determined from the alternative light flux distribution results according to the received selection instruction.

[0114] Exemplarily, when retrieving the light flux distribution result corresponding to the biological tissue type, the parameter information of the imaging target and the parameter information of the photoacoustic coupling material disposed on the surface of the imaging target can also be combined. The photoacoustic coupling material can be a water-based polymer gel coated on the skin surface of the imaging target, or the photoacoustic coupling material can be a gel pad that can be directly placed between the photoacoustic probe and the skin, etc., to play a coupling role and enable clearer imaging. The parameter information of the imaging target includes but is not limited to the thickness of each layer of tissue in the imaging target, such as the thickness of the skin layer and the thickness of the tissue layer; the parameter information of the photoacoustic coupling material includes but is not limited to the thickness of the photoacoustic coupling material.

[0115] The parameter information of the imaging target can also be determined in combination with user interaction. Specifically, an interactive interface for inputting parameter information can be provided on the display interface, and the parameter information of the imaging target is received through the interactive interface. Furthermore, a measurement tool can be provided on the ultrasound image to facilitate the user to measure parameters such as the thickness of each layer of tissue on the ultrasound image.

[0116] Alternatively, image recognition may be performed on the ultrasound image data to automatically obtain the biological tissue type and parameter information of the imaging target, and obtain the corresponding light flux distribution result based on the biological tissue type and parameter information, thereby eliminating the need for manual measurement by the user and improving measurement efficiency.

[0117] Reference Figure 3 , which shows the carotid artery and the nearby thyroid tissue, which are mainly divided into a gel cushion layer, a skin layer and a tissue layer. Through automatic or manual measurement, it can be known that the thickness of the gel cushion layer is about 3.5 mm, the thickness of the skin layer is about 1.5 mm, and below the skin layer is a mixed tissue containing muscle, carotid artery blood vessels and thyroid gland, with a depth range of 5 mm-25 mm. Based on the above information, the matching light flux distribution results can be retrieved in the database, or real-time modeling can be used to obtain the matching light flux distribution results.

[0118] Next, in step S230, photoacoustic image data of the imaging target is obtained, and the photoacoustic image data is obtained based on the actual photoacoustic imaging process. The imaging target can be photoacoustically imaged in real time to obtain the photoacoustic image data, or the photoacoustic image data stored after the imaging target is photoacoustically imaged can be obtained.

[0119] In the photoacoustic imaging process, the laser is controlled to emit laser pulses to the imaging target and receive the photoacoustic signal returned by the imaging target. Specifically, the laser pulse can be emitted to the imaging target through the optical fiber bundle coupled to the photoacoustic probe. When the imaging target absorbs the light energy, it will cause heating and thermal expansion, thereby generating a photoacoustic signal to propagate outward. For example, after the laser generates a laser pulse, feedback information can be returned to the processor, and the feedback information may include the actual sending time of the laser pulse. The processor can calculate the interval duration of receiving the photoacoustic signal according to a preset algorithm, and control the photoacoustic probe through a receiving circuit to receive the photoacoustic signal returned from the imaging target. After receiving the photoacoustic signal, the processor can remove the noise in the photoacoustic signal, and then obtain the photoacoustic image data of the imaging target through beam synthesis, image reconstruction and other processing.

[0120] Furthermore, in the process of photoacoustic imaging, it is necessary to use at least two lasers of different wavelengths for photoacoustic imaging to obtain photoacoustic image data corresponding to lasers of different wavelengths. A first laser having a first wavelength is emitted to the imaging target, a first photoacoustic signal corresponding to the first laser is received, and the first photoacoustic image data is obtained according to the first photoacoustic signal. Also, a second laser having a second wavelength is emitted to the imaging target, a second photoacoustic signal corresponding to the second laser is received, and the second photoacoustic image data is obtained according to the second photoacoustic signal. The first wavelength is different from the second wavelength, for example, the first laser is a short wavelength and the second laser is a long wavelength. Specifically, the laser can be controlled to alternately emit the first laser and the second laser to the imaging target to obtain the first photoacoustic signal and the second photoacoustic signal returned by the imaging target.

[0121] In step S240, compensation parameters of the photoacoustic image data are determined based on the light flux distribution result. Specifically, when the light flux distribution result is a one-dimensional light flux distribution result, light flux data of different imaging depths can be obtained according to the light flux distribution result, and the light flux data of different imaging depths can be determined as compensation parameters at corresponding depths, thereby obtaining one-dimensional compensation parameters. When the light flux distribution result is a two-dimensional light flux distribution result, light flux data of different imaging depths and different widths can be obtained according to the light flux distribution result, and the light flux data of different imaging depths and different widths can be determined as compensation parameters at corresponding imaging depths and corresponding widths, thereby obtaining two-dimensional compensation parameters. Alternatively, other operations can be performed on the light flux distribution result to obtain compensation parameters of the photoacoustic image data.

[0122] Next, in step S250, the photoacoustic image data is compensated based on the compensation parameters to obtain compensated photoacoustic image data. Specifically, the photoacoustic intensity signals at different imaging depths are compensated based on the compensation parameters.

[0123] For example, according to the principle of photoacoustic effect, the light absorption energy density A(r) under short pulse laser can be described as: A(r) = μ(r) × F(r), that is

[0124] μ(r)=A(r) / F(r)

[0125] Among them, r represents the position coordinate, F represents the luminous flux, and μ represents the absorption coefficient.

[0126] Therefore, when the compensation parameter is a one-dimensional compensation parameter, the compensated photoacoustic image data at different imaging depths is divided by the compensation parameter at the corresponding depth, and the compensated photoacoustic image data can be obtained. When the compensation parameter is a two-dimensional compensation parameter, the compensated photoacoustic image data at different imaging depths and different widths is divided by the compensation parameter at the corresponding depth and corresponding width, and the compensated photoacoustic image data can be obtained.

[0127] Exemplarily, when performing simulated imaging on a simulated target tissue, lasers of different wavelengths are simulated to irradiate the simulated target tissue, and light flux distribution results corresponding to lasers of different wavelengths are obtained. Specifically, the light flux distribution result includes a first light flux distribution result corresponding to the first wavelength and a second light flux distribution result corresponding to the second wavelength, and the compensation parameters obtained based on the light flux distribution results include a first compensation parameter determined based on the first light flux distribution result and a second compensation parameter determined based on the second light flux distribution result. When compensating the photoacoustic image data according to the compensation parameters, the first photoacoustic image data is compensated according to the first compensation parameter, and the second photoacoustic image data is compensated according to the second compensation parameter, so as to obtain the compensated first photoacoustic image data and the second photoacoustic image data, respectively.

[0128] Finally, in step S260, a photoacoustic image is generated according to the compensated photoacoustic image data. Specifically, blood oxygen reconstruction can be performed on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

[0129] Oxygen saturation (SaO2) refers to the percentage of oxygenated hemoglobin in the blood to all bindable hemoglobin, that is, the concentration of blood oxygen in the blood. In clinical practice, the oxygen content in the blood is assessed by testing arterial oxygen saturation. Under different physiological states, the metabolism of various organs and tissues of the human body is different, and the need for blood flow is also different. For example, compared with normal tissue, cancerous tissue usually presents the characteristics of "high blood and low oxygen". Dual-wavelength tissue detection technology based on photoacoustic imaging, that is, according to the different optical absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin in the near-infrared light region, detects blood flow signals and blood oxygen saturation in human tissues by emitting two specific wavelengths of infrared light, and then judges the benign or malignant nature of the tumor by comparing the blood oxygen content in diseased tissue and healthy tissue.

[0130] Specifically, the content of deoxyhemoglobin corresponding to each pixel and the content of oxygenated hemoglobin corresponding to each pixel can be obtained according to the pixel value of each pixel in the compensated first photoacoustic image data and the compensated second photoacoustic image data, and according to the extinction coefficient of deoxyhemoglobin corresponding to the first laser, the extinction coefficient of oxygenated hemoglobin corresponding to the first laser, the extinction coefficient of deoxyhemoglobin corresponding to the second laser, and the extinction coefficient of oxygenated hemoglobin corresponding to the second laser, SO2 is the blood oxygen saturation of the target pixel, and the blood oxygen saturation corresponding to each pixel is obtained according to the content of deoxyhemoglobin and the content of oxygenated hemoglobin corresponding to each pixel.

[0131] Afterwards, the blood oxygen saturation value corresponding to each pixel can be used as the pixel value of the pixel, or the blood oxygen saturation value of each pixel can be calculated according to a preset algorithm to obtain the pixel value of the pixel. According to the pixel value of each pixel, the blood oxygen saturation image of the imaging target can be obtained.

[0132] In summary, the photoacoustic imaging method 200 of the embodiment of the present invention determines the compensation parameters according to the light flux distribution results corresponding to the biological tissue information of the imaging target, and compensates the photoacoustic image data in a targeted manner according to the compensation parameters, thereby achieving the effect of enhancing the intensity of the photoacoustic signal and improving the imaging depth, and optimizing the quality and accuracy of the photoacoustic image.

[0133] Next, we will refer to Figure 8 A photoacoustic imaging method according to another embodiment of the present invention is described. Figure 8 FIG. 8 is a schematic flow chart of a photoacoustic imaging method 800 according to an embodiment of the present invention.

[0134] like Figure 8 As shown, a photoacoustic imaging method 800 according to an embodiment of the present invention includes the following steps:

[0135] In step S810, ultrasonic image data of an imaging target is acquired, and a biological tissue type of the imaging target is determined based on features of the ultrasonic image data;

[0136] In step S820, photoacoustic image data of the imaging target corresponding to the ultrasound image data is acquired, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process;

[0137] In step S830, a compensation parameter of the photoacoustic image data is determined based on the biological tissue type;

[0138] In step S840, the photoacoustic image data is compensated based on the compensation parameter to obtain compensated photoacoustic image data;

[0139] In step S850, a photoacoustic image is generated according to the compensated photoacoustic image data.

[0140] The main difference between the photoacoustic imaging method 800 of the embodiment of the present invention and the photoacoustic imaging method 200 described above is that in step S830, the compensation parameters of the photoacoustic image data are determined based on the biological tissue type, and the method is not limited to first determining the light flux distribution result corresponding to the biological tissue type and then determining the compensation parameters based on the light flux distribution result. For example, the compensation parameters for the photoacoustic image data at different depths can be pre-set, and different biological tissue types correspond to different compensation parameters. The compensation parameters can be set based on experience or by machine learning and other methods. This embodiment does not limit this. The acquisition of the compensation parameters can be based not only on the light flux distribution result, but also on other parameters corresponding to the biological tissue, such as the absorption and attenuation coefficient of the biological tissue itself.

[0141] Exemplarily, in step S820, first photoacoustic image data of the imaging target at a first wavelength corresponding to the ultrasound image data is acquired, and second photoacoustic image data of the imaging target at a second wavelength corresponding to the ultrasound image data is acquired, and the second wavelength is different from the first wavelength. In step S840, the first photoacoustic image data is compensated based on the compensation parameter to obtain the compensated first photoacoustic image data, and the second photoacoustic image data is compensated based on the compensation parameter to obtain the compensated second photoacoustic image data. In step S850, blood oxygen reconstruction is performed on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

[0142] The photoacoustic imaging method 800 of the embodiment of the present invention determines compensation parameters according to the light flux distribution results corresponding to the biological tissue information of the imaging target, and compensates the photoacoustic image data in a targeted manner according to the compensation parameters, thereby achieving the effect of enhancing the intensity of the photoacoustic signal and improving the imaging depth, and optimizing the quality and accuracy of the photoacoustic image.

[0143] The embodiment of the present invention further provides a photoacoustic imaging system, which is used to implement the above-mentioned photoacoustic imaging method 200 or photoacoustic imaging method 800. Figure 1 , the photoacoustic imaging system can be implemented as Figure 1The photoacoustic imaging system 100 shown in the figure may include a laser 110, a photoacoustic probe 112, a transmitting circuit 114, a receiving circuit 116, a processor 118 and a display 120. Optionally, the photoacoustic imaging system 100 may also include a transmitting / receiving selection switch 122 and a beamforming module 124. The transmitting circuit 114 and the receiving circuit 116 may be connected to the photoacoustic probe 112 through the transmitting / receiving selection switch 122. The laser 110 is used to transmit a laser to an imaging target so that the imaging target returns a photoacoustic signal; the receiving circuit 116 is used to control the photoacoustic probe 112 to receive the photoacoustic signal; the processor 118 is used to execute the photoacoustic imaging method 200 or the photoacoustic imaging method 800 as described above to generate a photoacoustic image based on the photoacoustic signal. The display 120 is used to display the photoacoustic image. The relevant description of each component can refer to the relevant description above, and will not be repeated here.

[0144] The above only describes the main functions of the components of the photoacoustic imaging system. For more details, refer to the relevant descriptions of the photoacoustic imaging method 200 and the photoacoustic imaging method 800. The photoacoustic imaging system 100 of the embodiment of the present invention compensates the photoacoustic image data in a targeted manner according to the light flux distribution result corresponding to the biological tissue information of the imaging target, thereby achieving the effect of enhancing the intensity of the photoacoustic signal and improving the imaging depth, and optimizing the quality and accuracy of the photoacoustic image.

[0145] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0146] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0147] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0148] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0149] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0150] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0151] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0152] The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functions of some modules according to embodiments of the present invention. The present invention can also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0153] It should be noted that the above embodiments illustrate rather than limit the invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of means, several of these means may be embodied by the same hardware item. The use of first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

[0154] The above is only a specific embodiment of the present invention or an explanation of a specific embodiment. The protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A photoacoustic imaging method, characterized in that: The method comprises: Acquiring ultrasound image data of an imaging target, and determining a biological tissue type of the imaging target based on features of the ultrasound image data; Determine a light flux distribution result corresponding to the biological tissue type, wherein the light flux distribution result is generated after laser irradiation of the simulated target tissue during simulated imaging of the simulated target tissue corresponding to the biological tissue type of the imaging target, and the light flux distribution result is used to characterize the light flux distribution of the biological tissue at different imaging depths relative to the body surface; Acquiring photoacoustic image data of the imaging target corresponding to the ultrasound image data, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process; determining a compensation parameter of the photoacoustic image data based on the light flux distribution result; Compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data; A photoacoustic image is generated according to the compensated photoacoustic image data.

2. The photoacoustic imaging method according to claim 1, characterized in that: The determining of the light flux distribution result corresponding to the biological tissue type of the imaging target comprises: Retrieving the light flux distribution result corresponding to the biological tissue type stored in advance from a database, wherein the light flux distribution result is obtained by performing simulated imaging on a simulated target tissue corresponding to the biological tissue type of the imaging target in advance; Alternatively, simulated imaging is performed on a simulated target tissue corresponding to the biological tissue type of the imaging target in real time to obtain the light flux distribution result.

3. The photoacoustic imaging method according to claim 2, characterized in that: Performing simulated imaging on a simulated target tissue corresponding to the biological tissue type of the imaging target to obtain the light flux distribution result includes: Establishing a simulated target tissue corresponding to the biological tissue type, and constructing a simulated laser light source above the simulated target tissue to simulate laser irradiation of the simulated target tissue; Obtaining constraint conditions of propagation characteristics of the laser in the simulated target tissue; The constraint condition is solved to obtain the light flux distribution result incident on the simulation target tissue.

4. The photoacoustic imaging method according to claim 1, characterized in that: The determining of the light flux distribution result corresponding to the biological tissue type comprises: Providing at least two options of alternative luminous flux distribution results on the display interface; A selection instruction for the option is received, and a light flux distribution result corresponding to the biological tissue type is determined from among the candidate light flux distribution results according to the selection instruction.

5. The photoacoustic imaging method according to claim 1, characterized in that: The light flux distribution result includes a two-dimensional distribution result of the light flux of the simulated target tissue at different imaging depths relative to the body surface.

6. The photoacoustic imaging method according to claim 1, characterized in that: The light flux distribution result includes a one-dimensional distribution result of the light flux of the simulated target tissue at different imaging depths relative to the body surface.

7. The photoacoustic imaging method according to claim 6, characterized in that: The one-dimensional distribution result of the light flux includes the one-dimensional distribution result of the light flux at the center position of the simulated imaging section in the simulated target tissue at different imaging depths.

8. The photoacoustic imaging method according to claim 1, characterized in that: The compensating the photoacoustic image data based on the compensation parameter includes: compensating the photoacoustic intensity signals at different imaging depths based on the compensation parameter.

9. The photoacoustic imaging method according to claim 1, characterized in that: The acquiring the photoacoustic image data of the imaging target corresponding to the ultrasound image data comprises: acquiring first photoacoustic image data of the imaging target corresponding to the ultrasound image data at a first wavelength; The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the first photoacoustic image data based on the compensation parameter to obtain compensated first photoacoustic image data.

10. The photoacoustic imaging method according to claim 9, characterized in that: The acquiring of the photoacoustic image data of the imaging target corresponding to the ultrasonic image data further includes: Acquire second photoacoustic image data of the imaging target corresponding to the ultrasound image data at a second wavelength, where the second wavelength is different from the first wavelength; The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the second photoacoustic image data based on the compensation parameter to obtain compensated second photoacoustic image data; Generating a photoacoustic image according to the compensated photoacoustic image data includes: performing blood oxygen reconstruction on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

11. The photoacoustic imaging method according to claim 10, characterized in that: The luminous flux distribution result includes a first luminous flux distribution result corresponding to the first wavelength and a second luminous flux distribution result corresponding to the second wavelength, and the compensation parameter includes a first compensation parameter determined based on the first luminous flux distribution result and a second compensation parameter determined based on the second luminous flux distribution result; The compensating the photoacoustic image data according to the compensation parameter includes: compensating the first photoacoustic image data according to the first compensation parameter, and compensating the second photoacoustic image data according to the second compensation parameter.

12. A photoacoustic imaging method, characterized in that: The method comprises: Acquiring ultrasound image data of an imaging target, and determining a biological tissue type of the imaging target based on features of the ultrasound image data; Acquiring photoacoustic image data of the imaging target corresponding to the ultrasound image data, wherein the photoacoustic image data is obtained based on an actual photoacoustic imaging process; determining a compensation parameter of the photoacoustic image data based on the biological tissue type; Compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data; A photoacoustic image is generated according to the compensated photoacoustic image data.

13. The photoacoustic imaging method according to claim 12, characterized in that: The acquiring the photoacoustic image data of the imaging target corresponding to the ultrasound image data comprises: acquiring first photoacoustic image data of the imaging target corresponding to the ultrasound image data at a first wavelength; The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the first photoacoustic image data based on the compensation parameter to obtain compensated first photoacoustic image data.

14. The photoacoustic imaging method according to claim 13, characterized in that: The acquiring of the photoacoustic image data of the imaging target corresponding to the ultrasonic image data further includes: Acquire second photoacoustic image data of the imaging target corresponding to the ultrasound image data at a second wavelength, where the second wavelength is different from the first wavelength; The compensating the photoacoustic image data based on the compensation parameter to obtain compensated photoacoustic image data includes: compensating the second photoacoustic image data based on the compensation parameter to obtain compensated second photoacoustic image data; Generating a photoacoustic image according to the compensated photoacoustic image data includes: performing blood oxygen reconstruction on the compensated first photoacoustic image data and the compensated second photoacoustic image data to obtain a blood oxygen saturation image.

15. A photoacoustic imaging system, characterized in that: The photoacoustic imaging system comprises: Photoacoustic probe; A laser, used for emitting laser light to an imaging target, so that the imaging target returns a photoacoustic signal; A receiving circuit, used for controlling the photoacoustic probe to receive the photoacoustic signal; A processor, configured to execute the photoacoustic imaging method according to any one of claims 1 to 14, so as to generate a photoacoustic image based on the photoacoustic signal; A display is used to display the photoacoustic image.

16. A storage medium having a computer program stored thereon, applied to a photoacoustic imaging system, wherein the computer program, when executed by a processor, implements the method according to any one of claims 1 to 14.

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