Phantoms and methods for sagittal plane transmission detection for three-dimensional ultrasound imaging devices

Abstract

This application belongs to the field of quality inspection of medical device imaging diagnostic equipment, specifically relating to a phantom and method for sagittal plane transmission imaging testing of a three-dimensional ultrasound imaging device. The phantom includes: a top panel, an acoustic window, a target group, and an aggregate of background ultrasound-simulated tissue material; the top panel is located above the acoustic window, and the connection between the top panel and the acoustic window forms an inner cavity; the target group and the aggregate of background ultrasound-simulated tissue material are located within the inner cavity; during sagittal plane transmission imaging performance testing, the tissue-simulated phantom is suspended in the imaging area of ​​a hemispherical ultrasound array, and the imaging area also contains degassed water; each target in the target group extends horizontally and is perpendicular to the sagittal plane of the breast to be imaged. This improves the convenience and accuracy of sagittal plane transmission imaging performance testing and has good practicality.

Description

Technical Field

[0001] This application belongs to the field of quality inspection of medical device imaging diagnostic equipment, and specifically relates to a phantom and method for sagittal plane transmission detection of three-dimensional ultrasound imaging equipment. Background Technology

[0002] Breast cancer is a malignant tumor that occurs in the epithelial tissue of the breast and is one of the leading diseases threatening women's lives and health. Compared with advanced breast cancer, benign breast lumps have a relatively better prognosis after treatment. Early and accurate localization and diagnosis of the nature of breast lumps can provide important reference for clinical treatment.

[0003] There are various methods for diagnosing breast diseases clinically, and the effectiveness of each method varies. Ultrasonic Computed Tomography (USCT) is a promising diagnostic technique for early-stage breast tumors. It uses a hemispherical ultrasound array probe to directly perform three-dimensional scanning imaging of the breast in water. Its imaging modes include sound velocity measurement imaging mode using transmitted wave signals and sound attenuation mode. According to quality system requirements and relevant regulations, all measuring instruments used for quality inspection by medical device manufacturers or professional quality inspection institutions must be periodically verified or calibrated. Imaging quality inspection of three-dimensional ultrasound imaging equipment using a hemispherical ultrasound array probe requires the use of a tissue phantom.

[0004] For ultrasound tomography devices with hemispherical ultrasound arrays, conventional tissue phantoms are no longer suitable for detecting their sagittal transmission imaging performance. Summary of the Invention

[0005] To address the above issues, this application provides a phantom and method for sagittal plane transmission detection of three-dimensional ultrasound imaging equipment, providing a tissue-like phantom suitable for detecting the sagittal plane transmission imaging performance of three-dimensional ultrasound tomography equipment.

[0006] In a first aspect, this application provides a phantom for sagittal plane transmission detection in a three-dimensional ultrasound imaging device, comprising:

[0007] The aggregate formed by the upper panel, acoustic window, target group, and background ultrasound-mimicking tissue material;

[0008] The upper panel is located above the acoustic window, and the upper panel and the acoustic window are connected to form an inner cavity;

[0009] The target group and the aggregate formed by the background ultrasound tissue-like material are located in the inner cavity;

[0010] During the sagittal plane transmission imaging performance test, the tissue-like phantom is suspended in the imaging area of ​​the hemispherical ultrasound array, and the imaging area also contains degassed water.

[0011] Each target in the target group extends horizontally and is perpendicular to the sagittal plane of the breast to be imaged.

[0012] Furthermore, the acoustic window is a hollow truncated cylinder made of thermoplastic plastic or heat-cured polyurethane rubber with a thickness of 50μm to 300μm.

[0013] Furthermore, the material of the top panel is acrylic glass, ABS plastic, or PVC plastic;

[0014] The top panel is equipped with various through holes or threaded holes.

[0015] Furthermore, the acoustic window includes an arc-shaped portion, a front cover portion, and a rear cover portion;

[0016] Each target is cylindrical and has a preset diameter;

[0017] Each target is horizontally penetrated along the central axis of the acoustic window to the front end cover portion and the rear end cover portion, and is embedded in the aggregate formed by the background ultrasound-simulated tissue material.

[0018] Furthermore, it also includes:

[0019] Multiple suspension screws;

[0020] The upper panel is provided with multiple through holes or threaded holes, and the multiple suspension screws are provided in the multiple through holes or threaded holes.

[0021] Furthermore, it also includes:

[0022] Multiple T-shaped columns;

[0023] The upper panel is provided with multiple through holes or threaded holes, and the T-shaped post is arranged in an inverted T shape in the multiple through holes or threaded holes. The head of the T-shaped post is located below the upper panel or the head of the T-shaped post is embedded in the aggregate formed by the background ultrasonic tissue-like material.

[0024] Furthermore, it also includes: a protective perimeter;

[0025] After the upper panel and the sound window are connected by adhesive, the protective ring is set at the adhesive joint between the upper panel and the sound window.

[0026] Furthermore, the material of each target in the target group is a first water-based polymer gel-based composite material;

[0027] The background ultrasonic tissue-mimicking material is a second water-based polymer gel-based composite material.

[0028] Furthermore, each target in the target group is a sound velocity target or a sound attenuation target;

[0029] When the target is a sound velocity target, the range of ultrasonic longitudinal wave velocity of the target is 1400 m / s to 1620 m / s.

[0030] When the target is an acoustic attenuation target, the slope of the ultrasonic longitudinal wave acoustic attenuation coefficient of the target ranges from 0 dB / (cm·MHz) to 2.0 dB / (cm·MHz).

[0031] Secondly, this application provides a method for sagittal plane transmission detection in a three-dimensional ultrasound imaging device, wherein the three-dimensional ultrasound imaging device is equipped with a hemispherical ultrasound array, and the method uses the phantom described in the first aspect above, the method comprising:

[0032] The phantom is suspended in the imaging region of a hemispherical ultrasonic array, and the imaging region also contains degassed water.

[0033] Turn on the imaging device and set all the array elements of the hemispherical ultrasound array to transmit-receive state, so that the ultrasound emitted by the array element on one side of the acoustic window passes through the background ultrasound tissue-like material aggregate and / or target and is received by the array element on the other side of the acoustic window.

[0034] Using each target embedded in the aggregate formed by the background ultrasound tissue-like material as the imaging target of transmission imaging, a three-dimensional image indicating the diameter or relative position of each target is obtained.

[0035] By segmenting the ultrasonic transmission image of the scanning plane perpendicular to the longitudinal extension direction of the target using display software, a sound velocity measurement image or a sound attenuation distribution image in three-dimensional mode is obtained.

[0036] The tissue-simulating phantom provided in this application can be used to measure hemispherical three-dimensional ultrasound equipment or similar surrounding probe equipment with rotating scanning structures. In terms of structural design, the phantom features acoustic windows that are transmissive in three directions: front, back, left, right, and bottom. A cylindrical target embedded in the background ultrasonic tissue-simulating material serves as the imaging target for the ultrasonic transmission imaging mode, enabling the measurement and evaluation of the sagittal plane transmission imaging performance of the imaging equipment. The phantom is maintainable; a maintenance fluid can be injected through the maintenance holes to maintain the stability of the composition of the ultrasonic tissue-simulating material inside the phantom, greatly increasing its service life. This improves the convenience and accuracy of sagittal plane transmission imaging performance testing, making it highly practical. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the various embodiments disclosed in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only a few embodiments disclosed in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] The accompanying drawings used in the description of the embodiments or prior art are briefly introduced below.

[0039] Figure 1 This is a schematic diagram of the appearance of a phantom from a stereoscopic perspective for sagittal plane transmission detection of a three-dimensional ultrasound imaging device, provided in an embodiment of this application.

[0040] Figure 2 This is a schematic diagram of the cross-section and internal perspective structure of a phantom for sagittal plane transmission detection of a three-dimensional ultrasound imaging device provided in the embodiments of this application.

[0041] Figure 3 This is a schematic diagram of the phantom's lateral view for sagittal plane transmission detection in a three-dimensional ultrasound imaging device, provided in an embodiment of this application.

[0042] Figure 4 This is a schematic diagram of ultrasonic scanning section segmentation of the ultrasonic tomography imaging device provided in the embodiments of this application;

[0043] Figure 5 This is a schematic diagram of an embodiment of the phantom used for sagittal plane transmission detection of a three-dimensional ultrasound imaging device provided in this application.

[0044] Figure 6 This is a schematic diagram of the clinical implementation of the hemispherical ultrasound tomography device provided in the embodiments of this application;

[0045] Figure 7 This is a schematic diagram of the three-dimensional structural segmentation of a standing human body ultrasound transmission image.

[0046] Figure label:

[0047] 1. Tissue-like phantom; 2. Top panel; 3. Acoustic window; 4. Background ultrasound tissue-like material; 5. Suspension screw; 6. T-shaped column; 7. Sealing rubber; 8. Protective ring; 9. Target; 10. Maintenance hole; 11. Hemispherical 3D ultrasound imaging device probe; 12. Hemispherical 3D ultrasound imaging device array probe element; 13. Degassed water body; 14. Sagittal plane; 15. Sagittal / transverse plane; 16. Subject; 17. Equipment bed. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings.

[0049] In the description of the embodiments of this application, words such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.

[0050] In the description of the embodiments in this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. Furthermore, unless otherwise stated, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple terminals refer to two or more terminals.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0052] In the description of the embodiments in this application, "some embodiments" are mentioned, which describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0053] In the description of the embodiments of this application, the terms "first, second, third, etc." or module A, module B, module C, etc. are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that, where permitted, a specific order or sequence can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0054] In the description of the embodiments of this application, the reference numerals for the steps, such as S110, S120, etc., do not necessarily indicate that the steps will be executed in this manner. Where permissible, the order of the steps can be interchanged or executed simultaneously.

[0055] The following section introduces the technical background and some terminology of this application.

[0056] The breast is an organ unique to mammals. In women of childbearing age, mammary gland tissue accounts for about 1 / 3 to 1 / 2 or even more of the breast, with the remainder being fat, fibrous connective tissue, etc. Among them, the suspensory ligaments of the breast play a role in supporting and fixing the breast; the skin, superficial fascia, and deep fascia on the surface of the breast are structures that enclose and separate the breast; blood vessels, lymphatic vessels, nerves, etc. are responsible for blood supply, lymphatic return, and sensory conduction.

[0057] Ultrasound longitudinal waves can propagate in both solids and liquids, exhibiting strong penetrating power. Ultrasonic computed tomography (USCT) is one of the most promising technologies for the early detection and diagnosis of breast tumors. USCT uses an ultrasound transducer to perform tomographic imaging of the breast submerged in degassed water. USCT utilizes degassed water as the coupling medium between the ultrasound transducer and the breast, providing excellent acoustic performance. While primarily used for three-dimensional ultrasound imaging of the breast, USCT can also be used for tomographic imaging of the limbs or brain.

[0058] like Figure 6 As shown, when performing three-dimensional scanning tomographic imaging of a human breast using an ultrasound tomography device, subject 16 lies prone on the device bed 17, with one breast immersed in degassed water, allowing the breast to droop naturally. Figure 4 As shown, the probe 11 of the breast ultrasound tomography device has an array of elements 12 arranged along a hemispherical cap. The cavity surrounding the array elements 12 is the hemispherical ultrasound array imaging area, which is filled with degassed water to form a hemispherical degassed water body that contains the breast to be imaged. The array elements 12 include multiple sets of ultrasound transducers, arranged vertically or along the z-axis, with each set of ultrasound transducers located at different heights, and can have 256 or even 2048 elements.

[0059] Figure 4 This is a schematic diagram of ultrasonic scanning section segmentation using a three-dimensional ultrasonic tomography (3D ultrasound) imaging device, which can be compared with... Figure 7 The schematic diagram of the three-dimensional structural segmentation of the standing human ultrasound transmission image shown serves as a reference. To achieve independent single-variable control, the three-dimensional ultrasound field is decomposed into coronal imaging detection and sagittal / transverse imaging detection. The coronal plane consists of horizontal planes perpendicular to the rotational symmetry axis z of the hemispherical array center, while the sagittal / transverse plane consists of planar directions coplanar with the symmetry axis of the hemispherical array. Since the sagittal and transverse planes have 90° rotational symmetry, their detection directions are equivalent and can therefore be combined into one.

[0060] Specifically, the gas content of the degassed water used in USCT breast imaging media should be ≤0.6-2 ppm (0.6-2 mg / L), with the bubble content approaching zero and the pressure at 0.1-0.2 MPa. This can greatly avoid interference from ultrasound signal scattering and ensure stable sound velocity and imaging accuracy.

[0061] In sagittal transillumination imaging of the breast, the probes emit and receive ultrasound waves from opposite sides of the breast. The sound waves penetrate the tissue longitudinally along the sagittal plane, carrying information such as sound attenuation and velocity. The transmitted sound waves are reconstructed to recreate the sound velocity and attenuation, converting the transmitted energy distribution into a two-dimensional grayscale image. This visually displays the tissue homogeneity, attenuation differences, and structural morphology within the sagittal plane, making it suitable for imaging with large thickness and a wide field of view.

[0062] like Figure 4 , Figure 5 and Figure 6 As shown, in a breast ultrasound scenario, the sagittal plane extends along the longitudinal section of the subject and is perpendicular to the chest wall. Relative to the subject, a series of sagittal planes extend in the left-right direction (e.g., parallel to the xoz plane) and are arranged parallel to each other in the front-back direction. Alternatively, from the upper pole to the lower pole of the breast, each height corresponds to a sagittal plane, and continuous slices form a series of sagittal planes. In actual imaging, a series of sagittal planes are imaged as dozens of sagittal plane images, which are then combined into three-dimensional volumetric data. USCT, through its three-dimensional reconstruction algorithm, can achieve sub-millimeter spatial resolution, with a sensitivity of up to 92% for detecting microcalcifications in dense breast tissue. The lesion detection rate is more than 40% higher than that of traditional ultrasound, meeting the needs of early tumor detection.

[0063] In breast ultrasound scenarios, USCT transmission imaging modes are divided into sound velocity imaging mode and sound attenuation imaging mode. It can invert and measure the sound velocity or sound attenuation value of ultrasound longitudinal wave inside the breast and display the sound velocity and sound attenuation distribution and quantitative value of various tissues inside the breast in real time.

[0064] Referring to the foregoing description, conventional tissue phantoms are no longer suitable for detecting the sagittal transmission imaging performance of three-dimensional ultrasonic tomography equipment with multiple ultrasonic transducers.

[0065] This application provides a maintainable tissue-like phantom, which, based on the structural characteristics of ultrasound computed tomography (CT) equipment, is lightweight and simple in principle, and can conveniently, efficiently and accurately conduct the detection and evaluation of the sagittal transmission imaging performance of ultrasound CT equipment.

[0066] like Figure 5 As shown, this tissue phantom is a passive device used to test the sagittal plane transmission sound velocity imaging performance and sagittal plane transmission sound attenuation imaging performance of a hemispherical three-dimensional ultrasound tomography imaging device.

[0067] like Figure 1 , Figure 2 , Figure 3 and Figure 5As shown, in use, this tissue-simulating model 1 includes an externally visible upper panel 2, an acoustic window 3, an internally embedded target group 9 that is not visible to the outside, and an aggregate or tissue-simulating body 4 formed by background ultrasonic tissue-simulating material.

[0068] This sagittal transmissive imaging phantom has acoustic windows that can transmit in three directions: front, back, left, right, and down. The upper panel 2 is located above the acoustic window 3. The connection between the upper panel 2 and the acoustic window 3 can be regarded as the outer shell of the phantom.

[0069] Within the truncated cylindrical cavity enclosed by the acoustic window 3, background ultrasound tissue-mimicking material is filled and formed into the cavity, creating an aggregate of background ultrasound tissue-mimicking material (TMM). For example... Figure 5 As shown, when set in degassed water, each target in the target group 9 embedded in the aggregate extends horizontally or parallel to the y-direction and is perpendicular to the sagittal plane of the breast to be imaged. It is used for ultrasound imaging detection and serves as a measurement target.

[0070] The top panel 2 is made of acrylic glass (polymethyl methacrylate, PMMA), ABS plastic (acrylonitrile-butadiene-styrene polymer, ABS plastic), or PVC plastic (polyvinyl chloride). It is manufactured by cutting sheet material according to the design dimensions of the top panel or by direct thermoforming followed by injection molding. The various through holes or threaded holes in the top panel 2 are formed by stamping.

[0071] like Figure 1 , Figure 2 and Figure 3 As shown, the upper panel 2 is provided with several through holes or threaded holes, and several suspension screws 5 are connected to the through holes or threaded holes, and are evenly arranged in a regular polygonal pattern on the upper panel 2. Specifically, the suspension screws are provided with threaded portions, and after being installed on the upper panel 2, the threaded portions of the suspension screws 5 are located above the upper panel 2. During performance testing, after the suspension device is connected to the suspension screws, the suspension device suspends the entire phantom vertically in the hemispherical ultrasound array imaging area. The suspension device can be flexibly selected and will not be described in detail further.

[0072] like Figure 1 , Figure 2 and Figure 3As shown, the acoustic window 3 is a truncated cylinder, made of thermoplastic plastic or thermo-vulcanized polyurethane rubber (TPU) with a thickness of 50μm to 300μm. Thus, when the upper panel and acoustic window are connected, they form a whole shell, surrounding the aggregate formed by the background ultrasonic tissue-like material, providing a sealing and protective function. In addition to its structural function, the acoustic window 3 also serves as a window for sound waves to pass through and enter the phantom; its material and thickness can accurately and effectively simulate the acoustic characteristics of human epidermal tissue.

[0073] Background: The ultrasonic tissue-mimicking material aggregates are used to mimic the ultrasonic properties of human soft tissue. They are a second type of water-based polymer gel-based composite material. The aggregates are transparent gels with uniform texture and stable morphology, and are used as a whole to simulate the soft tissue within the breast.

[0074] Specifically, the sound velocity of the background ultrasound tissue-like material was (1540±10) m / s, and the slope of the sound attenuation coefficient ranged from (0.70±0.05) dB / (cm·MHz) to (0.50±0.05) dB / (cm·MHz). These parameters were all measured at a temperature of (23±3)℃.

[0075] In some embodiments, the upper panel 2 and the acoustic window 3 are connected by adhesive bonding to maintain the internal space sealing. To increase structural rigidity and ensure reliable and secure connection, a protective ring 8 is provided at the adhesive joint between the upper panel 2 and the acoustic window 3. This strengthens the connection between the upper panel 2 and the acoustic window 3, protects the adhesive joint, and helps prevent the overall structure of the model from falling off and being damaged.

[0076] like Figure 1 , Figure 2 and Figure 3 As shown, the arc-shaped portion of the acoustic window 3 is not closed and opens upwards. The arc-shaped portion, front cover portion, and rear cover portion of the acoustic window 3 combine to form a truncated cylindrical shell. Correspondingly, the cross-section of the protective ring 8 is a T-shaped structure. Where it overlaps with the upper panel 2, the protective ring 8 is a closed rectangular ring; where it overlaps with the acoustic window 3, the protective ring 8 is a closed arc-shaped flange or a flat flange. Specifically, where it connects with the arc-shaped portion of the acoustic window 3, the protective ring 8 is an arc-shaped flange; where it connects with the front cover portion or the rear cover portion of the acoustic window 3, the protective ring 8 is a flat flange. The protective ring 8 can...

[0077] like Figure 1 , Figure 2 and Figure 3 As shown, the upper panel 2 is also evenly provided with several through holes or threaded holes. Several T-shaped posts 6 are fixed to the upper panel 2 in an inverted T shape, with the head of the T-shaped posts located below the upper panel 2 and the tail of the T-shaped posts located in the through holes or threaded holes.

[0078] like Figure 2 and Figure 3 As shown, the head of the T-shaped column is disc-shaped. Background ultrasound-simulated tissue material is filled and formed into an aggregate within the cavity, and the head of the T-shaped column is embedded within the aggregate 4 formed by the background ultrasound-simulated tissue material. Thus, the aggregate is connected to the upper panel 2 via the T-shaped column.

[0079] like Figure 2 and Figure 3 As shown, each measurement target is cylindrical in shape, and the diameter of the target 9 ranges from 0mm to 20mm, such as 4mm, 8mm, etc. Each target 9 is horizontally set along the central axis of the arc-shaped part of the acoustic window 3, and each target is embedded in the background ultrasonic tissue-like material and its aggregates 4.

[0080] Each measurement target is cylindrical in shape. Compared with regular polygonal cross-sections such as triangular or quadrangular prisms, the circular cross-section has the same dimensions (such as radius) in all vertical directions, which is beneficial to the isotropic nature of the detection indicators and ensures the consistency of the detection results.

[0081] The targets used for measurement are made of a first-generation aqueous polymer gel-based composite material. The target material and the background ultrasound tissue-mimicking material do not interwet or corrode each other, and can maintain the stability of their respective components for a long time.

[0082] Each target 9 is classified as either a sound velocity target or a sound attenuation target based on the transmission imaging mode. A single phantom can contain individual sound velocity targets and sound attenuation targets, or a combination thereof. When it is a sound velocity target, the ultrasonic longitudinal wave velocity of the target ranges from 1400 m / s to 1620 m / s. When it is a sound attenuation target, the slope of the ultrasonic longitudinal wave sound attenuation coefficient of the target ranges from 0 dB / (cm·MHz) to 2.0 dB / (cm·MHz).

[0083] When a combination of sound velocity targets and sound attenuation targets is included in the same phantom, in transmission imaging mode, both sound velocity targets and sound attenuation targets will be in the sound field without interfering with each other, because the materials of the targets can transmit sound waves. During detection, sound velocity targets and sound attenuation targets can be detected and imaged simultaneously in the same experiment, but different modal algorithms are used for sound velocity targets and sound attenuation targets.

[0084] Targets are used to test the imaging capability of three-dimensional ultrasound scanning imaging equipment in the sagittal plane under transmission imaging mode. Acquiring and analyzing the measurement and imaging results of acoustic velocity targets or acoustic attenuation targets of various sizes under computed tomography imaging equipment, and combining this with quantitative indicators of the equipment's transmission imaging performance, can serve as the test results for the equipment's transmission imaging performance.

[0085] The targets at different locations only represent the transmission resolution capability of the imaging device at that location. If the performance indicators of the imaging device are the same for multiple targets uniformly distributed at different locations in the sound field, then the sound velocity resolution capability of the imaging device in that sound field is a fixed value.

[0086] Naturally, the number of targets 9 can be set according to requirements. To minimize the mutual obstruction of sound waves, the targets are positioned so that they are horizontally parallel to each other along the central axis of the arc-shaped portion of the acoustic window 3, and are distributed as dispersedly as possible within the aggregates formed by the background ultrasound-mimicking tissue material. Referring to the foregoing description, the targets 9 and the aggregates 4 are made of aqueous polymer gel-based composite materials with different formulations, and their morphology and properties remain stable.

[0087] like Figure 2 As shown, a maintenance hole 10 is provided near the edge of the upper panel 2. This hole serves as a channel for injecting background ultrasonic tissue-like material into the phantom, and also as an inlet for liquid injection and air extraction during the maintenance of the background ultrasonic tissue-like material. Figure 1 and Figure 3 As shown, after filling, the maintenance hole is sealed by a highly elastic sealing rubber 7. After the sealing rubber 7 completely covers the maintenance hole 10, the edge part is attached to the upper panel 2.

[0088] The tissue-like body 4, composed of background ultrasonic tissue-like material, is the core part of the phantom. Variations in its composition, state, and acoustic properties will cause it to fail as a background medium. The liquid contained in the background ultrasonic tissue-like material may evaporate and be lost through the gaps in the phantom shell, or the background ultrasonic tissue-like material may lose water and shrink after prolonged use. In the case of severe water loss, the aggregates formed by the background ultrasonic tissue-like material may completely fail and become irreversible.

[0089] Specifically, the background ultrasonic tissue-simulating material of this tissue-simulating phantom is maintainable and can be routinely maintained using an aqueous maintenance solution. Specifically, the aqueous maintenance solution can be injected using a syringe needle after removing the sealing rubber 7 to expose the maintenance hole 10. This aqueous maintenance solution is specially formulated and suitable for this background ultrasonic tissue-simulating material.

[0090] Specifically, the routine maintenance cycle is related to the temperature and humidity environment of the tissue-simulating phantom, and the maintenance cycle can be flexibly determined according to local climate conditions. In this way, the aggregates formed by the background ultrasound tissue-simulating material are maintainable, and routine maintenance by replenishing the maintenance solution can greatly increase the service life of the phantom and extend its lifespan.

[0091] The tissue-like phantom designed and manufactured according to the technical solution of this application is specifically used for the testing and evaluation of the sagittal transmission mode imaging performance of a hemispherical array ultrasound tomography imaging device. By designing the distribution of target groups along the circumference of the arc-shaped portion of the acoustic window 3 or the radial direction of the aggregate, the imaging capability of the ultrasound tomography imaging device in the sagittal plane, based on sound velocity or sound attenuation parameters, can be measured. During sagittal transmission mode imaging performance testing, each target embedded in the background ultrasound tissue-like material and its diameter are used as the imaging target and quantitative indicator for the transmission imaging mode. By measuring the diameter of the target through sagittal imaging and comparing the measurement result with the nominal diameter of the target, the sagittal imaging performance can be detected.

[0092] The following details the sagittal transmissivity phantom for testing provided in this application from multiple aspects, including the principle design, structural design, material selection, structural component processing or manufacturing, overall phantom assembly, on-site installation, and performance testing scenarios.

[0093] like Figure 1 As shown, the structure of the phantom 1 includes a top panel 2, an acoustic window 3, and a target assembly 9. The phantom 1 has a single-sided truncated cylindrical shape. The arc-shaped portion of the acoustic window 3 is not closed and opens upwards. The arc-shaped portion of the acoustic window 3, the front cover portion, and the rear cover portion are combined to form a truncated cylindrical shell.

[0094] Each cylindrical target with a preset diameter in target group 9 is positioned at a preset location within the cavity enclosed by the acoustic window, perpendicular to the sagittal plane. Naturally, the dimensions of the different targets are precisely manufactured, and their placement is precisely designed and arranged.

[0095] Subsequently, the upper panel 2 is placed over the opening side of the arc-shaped portion of the acoustic window 3, and the upper panel 2 and the acoustic window 3 are then bonded together to achieve connection. Each bonded joint is well-sealed to maintain the internal space, i.e., the aforementioned inner cavity, as a closed space with an opening. At this point, the upper panel 2 and the acoustic window 3 form a closed inner cavity, within which a target group is placed as the imaging target.

[0096] Before covering the opening side of the arc-shaped portion of the sound window 3 with the upper panel 2, the T-shaped post 6 is placed in the corresponding bolt hole of the upper panel 2, wherein the disc-shaped head of the T-shaped post is located below the upper panel 2, and the threaded tail or rod-shaped tail of the T-shaped post extends above the upper panel 2, such that the connection length between the threaded tail or rod-shaped tail and the upper panel is 10mm.

[0097] Before covering the opening side of the arc-shaped portion of the sound window 3 with the upper panel 2, the suspension screw 5 is placed in the corresponding bolt hole of the upper panel 2, wherein the head of the suspension screw 5 is located below the upper panel 2, and the threaded end of the suspension screw 5 extends above the upper panel 2.

[0098] To ensure that the upper panel 2 and the sound window 3 are reliably connected and remain firmly connected under external force, the protective ring 8 is fastened to the joint position of the upper panel 2 and the sound window 3, or is bonded to the upper panel 2 and the sound window 3 respectively.

[0099] After fastening the protective ring 8 to the joint between the upper panel 2 and the acoustic window 3, the ultrasonic tissue-like material is filled into the inner cavity through the maintenance hole 10, forming an aggregate as an imaging background. It is foreseeable that the ultrasonic tissue-like material filled into the inner cavity will have an irregular shape; for convenience, it will be referred to as a tissue-like body in this document. After filling, as shown... Figure 2 and Figure 3 As shown, within the inner cavity, the T-shaped cylindrical head disk is embedded in an aggregate 4 formed by background ultrasound-simulated tissue material. Each cylindrical target 9 is embedded in this tissue-simulated body, with a fixed orientation or distance relative to the upper panel 2, serving as a measurement target for imaging detection.

[0100] After the ultrasonic tissue-like material is injected into the cavity, the T-shaped column is embedded in the tissue-like body in an inverted T shape, connecting the entire tissue-like body to the upper panel 2. This allows the upper panel to bear most of the weight of the tissue-like body, reducing or even completely eliminating the weight ratio of the tissue-like body and target borne by the acoustic window. On the other hand, under the action of gravity and internal pressure, after filling, the ultrasonic tissue-like material fits tightly with all parts of the acoustic window, providing a sealing effect.

[0101] Subsequently, the maintenance hole 10 is sealed with a highly elastic sealing rubber 7, thereby isolating the simulated tissue inside the cavity from the external environment. The acoustic window 3, with a thickness of 50μm-300μm, can effectively simulate the acoustic characteristics of human epidermal tissue.

[0102] like Figure 1 As shown, after delivery to the user, the upper panel 2 is equipped with several suspension screws 5, such as three; and the threads of the suspension screws 5 are exposed. When using the phantom to test the sagittal imaging performance, the suspension device is connected to the phantom through the suspension screws 5, suspending the entire phantom in the hemispherical ultrasound array imaging area.

[0103] The ultrasonic tissue-mimicking material is a second water-based polymer gel-based composite material, which is a solid gel. Under the condition of (23±3)℃, the measured sound velocity is (1540±10) m / s, and the measured sound attenuation coefficient slope ranges from (0.70±0.05) dB / (cm·MHz) to (0.50±0.05) dB / (cm·MHz).

[0104] The acoustic window, acting as a passageway for sound waves to enter and exit the phantom, is designed to mimic the acoustic properties of human skin tissue in terms of material and thickness. Specifically, the acoustic window 3 is made of thermoplastic material, such as heat-cured polyurethane rubber (TPU).

[0105] Specifically, the acoustic window 3 can be obtained by cutting and pasting or hot pressing a rigid film with a thickness of 50μm to 300μm, and its overall shape is a single-sided truncated cylinder.

[0106] In ultrasound imaging, equipment testing, and algorithm verification, ultrasound-simulated tissue materials are used to simulate normal human tissue (such as normal breast tissue) and can generally be considered as the background. Target lesions, such as tumors, cysts, calcifications, and nodules, are the core observation targets and can generally be considered as the foreground. Since the background ultrasound-simulated tissue material simulates normal tissue, its sound velocity, attenuation, and acoustic impedance are almost identical to normal breast / human tissue. During imaging, it appears as a uniform, featureless, and abnormal signal-free region, providing a uniform and stable acoustic substrate, constituting the background environment for ultrasound imaging and detection, and serving to highlight the target structure corresponding to the target lesion.

[0107] like Figure 2 and Figure 3 As shown, each target extends parallel from one end of acoustic window 3 to the other. The positioning and location accuracy of the targets are satisfied by the manufacturing process and will not be elaborated further.

[0108] Targets are classified into acoustic velocity targets or acoustic attenuation targets based on the transmission imaging mode. When the target is an acoustic velocity target, its ultrasonic longitudinal wave velocity ranges from 1400 m / s to 1620 m / s. When the target is an acoustic attenuation target, its ultrasonic longitudinal wave acoustic attenuation coefficient slope ranges from 0 dB / (cm·MHz) to 2.0 dB / (cm·MHz). Naturally, different material formulations result in different acoustic parameters.

[0109] Naturally, the number of targets 9 can be set according to requirements. The targets are positioned parallel to each other and distributed as dispersedly as possible within the simulated tissue, while minimizing acoustic wave obstruction. Typically, the diameter of the targets 9 is no greater than 20mm, such as 4mm or 8mm.

[0110] Sound velocity targets or sound attenuation targets are used to test the imaging capability of three-dimensional ultrasound scanning imaging equipment in the sagittal plane in transmission imaging mode. Figure 5 This is a schematic diagram illustrating the use of this tissue-like phantom for testing the transmission imaging performance of a hemispherical three-dimensional ultrasound imaging device. Figure 5 As shown, the ultrasonic probe 11 is a hemispherical ultrasonic probe array, and its array elements 12 have radiation surfaces distributed on the inner side of the hemisphere. The overall structure of the hemispherical space is a semi-enclosed water tank. The water injected into the water tank needs to be degassed and is called degassed water body 13.

[0111] When the phantom is used for sagittal transmission imaging performance testing, the suspension nut and suspension screw 5 of the suspension device are threaded together, and the entire phantom is suspended vertically within the imaging area of ​​the hemispherical ultrasound array. Naturally, the imaging area also contains degassed water. The orientation of the front and rear cover portions of the acoustic window 3 is adjusted to align with the plane of the human body along its height or length, so that the sound velocity target or sound attenuation target is perpendicular to the sagittal plane along its axis. This ensures that the central axis of symmetry of the phantom coincides with the longitudinal central axis of the hemispherical ultrasound array.

[0112] Take measures to remove air bubbles attached to the acoustic window to prevent them from disrupting the sound field.

[0113] Turn on the imaging device and set it to full-element transmit-receive mode. Align the radiating surface with the acoustic window 3 of the phantom. The array elements inside the probe will automatically perform electronic scanning to obtain three-dimensional images of each sound velocity target or sound attenuation target within the phantom. The display software will then segment the ultrasound transmission image of the scanning plane perpendicular to the longitudinal extension direction of the targets inside the phantom, i.e., the sound velocity or sound attenuation distribution image on the sagittal plane.

[0114] After testing the sagittal imaging performance using the phantom, remove the phantom from the deaerated water, wipe off any water on the surface with a soft towel, and store it properly.

[0115] When testing the performance of sagittal transmission mode imaging, different diameter targets can be used in combination during resolution measurement, such as 2mm cylindrical targets and 4mm cylindrical targets. If the imaging device can clearly image a target, the resolution can be considered to have reached that level.

[0116] In summary, this tissue-simulating phantom can measure hemispherical 3D ultrasound devices or similar surrounding probe devices with rotating scanning structures. Unlike existing similar products, this tissue-simulating phantom features acoustic windows that are transmissive in three directions (front, back, left, right, and bottom). A cylindrical target embedded in the background ultrasonic tissue-simulating material serves as the imaging target for the ultrasonic transmission imaging mode, enabling the measurement and evaluation of the sagittal transmission imaging performance of hemispherical 3D ultrasound devices or similar devices with rotating structures. The phantom is maintainable; a maintenance fluid can be injected through the maintenance holes to maintain the stability of the composition of the ultrasonic tissue-simulating material inside the phantom, significantly increasing its service life.

[0117] It should be noted that the shapes, relative dimensions, and positional relationships of the components shown in the accompanying drawings are merely illustrative representations to clearly illustrate the technical solution and are not drawn to the exact manufacturing scale of the actual product. The proportional relationships of length, width, thickness, angles, and spacing between different components in the drawings do not constitute a precise limitation of the actual structure, nor do they have a definite proportional meaning. Those skilled in the art should not infer the actual or relative dimensions of the components based on the visual proportions in the drawings when understanding the technical solution. The actual shape, size, and fit of each component should be based on the description in the specification and actual manufacturing or design requirements. The method of drawing the drawings does not constitute any limitation on the scope of protection of the claims.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. A phantom for sagittal plane transmission detection of a three-dimensional ultrasound imaging device, characterized in that, include: The aggregate formed by the upper panel, acoustic window, target group, and background ultrasound-mimicking tissue material; The upper panel is located above the acoustic window, and the upper panel and the acoustic window are connected to form an inner cavity; The target group and the aggregate formed by the background ultrasound tissue-like material are located in the inner cavity; During the sagittal plane transmission imaging performance test, the tissue-like phantom is suspended in the imaging area of ​​the hemispherical ultrasound array, and the imaging area also contains degassed water. Each target in the target group extends horizontally and is perpendicular to the sagittal plane of the breast to be imaged.

2. The phantom as described in claim 1, characterized in that, The acoustic window is a hollow, truncated cylinder made of thermoplastic plastic or heat-cured polyurethane rubber with a thickness of 50μm to 300μm.

3. The phantom as described in claim 1, characterized in that, The top panel is made of acrylic glass, ABS plastic, or PVC plastic; The top panel is equipped with various through holes or threaded holes.

4. The phantom as described in claim 3, characterized in that, The acoustic window includes an arc-shaped portion, a front cover portion, and a rear cover portion; Each target is cylindrical and has a preset diameter; Each target is horizontally penetrated along the central axis of the acoustic window to the front end cover portion and the rear end cover portion, and is embedded in the aggregate formed by the background ultrasound-simulated tissue material.

5. The phantom of claim 3, wherein, Also includes: Multiple suspension screws; The upper panel is provided with multiple through holes or threaded holes, and the multiple suspension screws are provided in the multiple through holes or threaded holes.

6. The phantom of claim 3, wherein, Also includes: Multiple T-shaped columns; The upper panel is provided with multiple through holes or threaded holes, and the T-shaped post is arranged in an inverted T shape in the multiple through holes or threaded holes. The head of the T-shaped post is located below the upper panel or the head of the T-shaped post is embedded in the aggregate formed by the background ultrasonic tissue-like material.

7. The phantom of claim 3, wherein, Also includes: Protective ring; After the upper panel and the sound window are connected by adhesive, the protective ring is set at the adhesive joint between the upper panel and the sound window.

8. The phantom as described in any one of claims 1 to 7, characterized in that, The material of each target in the target group is a first water-based polymer gel-based composite material; The background ultrasonic tissue-mimicking material is a second water-based polymer gel-based composite material.

9. The phantom as described in any one of claims 1 to 7, characterized in that, Each target in the target group is a sound velocity target or a sound attenuation target. When the target is a sound velocity target, the range of ultrasonic longitudinal wave velocity of the target is 1400 m / s to 1620 m / s. When the target is an acoustic attenuation target, the slope of the ultrasonic longitudinal wave acoustic attenuation coefficient of the target ranges from 0 dB / (cm·MHz) to 2.0 dB / (cm·MHz).

10. A method for sagittal plane transmission detection in a three-dimensional ultrasound imaging device, characterized in that, The three-dimensional ultrasound imaging device is equipped with a hemispherical ultrasound array, and the method uses a phantom as described in any one of claims 1-9, the method comprising: The phantom is suspended in the imaging region of a hemispherical ultrasonic array, and the imaging region also contains degassed water. Turn on the imaging device and set all the array elements of the hemispherical ultrasound array to transmit-receive state, so that the ultrasound emitted by the array element on one side of the acoustic window passes through the background ultrasound tissue-like material aggregate and / or target and is received by the array element on the other side of the acoustic window. Using each target embedded in the aggregate formed by the background ultrasound tissue-like material as the imaging target of transmission imaging, a three-dimensional image indicating the diameter or relative position of each target is obtained. By segmenting the ultrasonic transmission image of the scanning plane perpendicular to the longitudinal extension direction of the target using display software, a sound velocity measurement image or a sound attenuation distribution image in three-dimensional mode is obtained.

Images