Mammary gland coupling, fixing and shaping device and method for ultrasonic imaging of mammary gland

Abstract

The present invention provides a mammary gland coupling, fixing and shaping device and method for ultrasound imaging of mammary glands, which device relates to the field of ultrasonic imaging. In the device, an inner ring of an SGCA couplant shapes, on a coronal plane at each depth, a mammary gland into a circle concentric with an annular array transducer, and limits the slope of sagging skin of the mammary gland on a sagittal plane and a cross section; an inner ring of a support table is configured to support the inner ring of the SGCA couplant and pull the mammary gland and fix and shape the mammary gland in the inner ring of the SGCA couplant; the inner ring of the SGCA couplant and an outer ring of the SGCA couplant are used for coupling between the mammary gland and the annular array transducer; and the annular array transducer is used to perform ultrasonic scanning imaging on the mammary gland. The present invention solves the problems of the use of debubbled water for coupling during scanning leading to excess preparation time and thus affecting the inspection throughput, motion artifacts being formed on an image due to slight movements of the mammary gland during scanning, and the scanning effect being poor due to various mammary gland shapes.

Description

Breast coupling fixation and shaping device and method for breast ultrasound imaging

Technical field

[0001] The present invention belongs to the field of ultrasonic imaging, and more particularly, relates to a breast coupling fixation and shaping device and method for breast ultrasonic imaging. [Background Technology]

[0002] Ultrasound tomography technology has the advantages of traditional ultrasound, such as safety and lack of radiation. Similar to X-CT and MRI, it can also be used for offline film reading and diagnosis. Not only does it reconstruct images using reflected echo information, similar to traditional ultrasound, but it can also reconstruct transmission images using transmission information. Ultrasound tomography systems generally use a multi-element surround probe to scan objects, such as the currently popular annular array probe, or a surround probe formed by splicing multiple linear arrays. Currently, ultrasound tomography technology is primarily used for early detection of breast cancer and is gradually being applied to other medical applications, such as musculoskeletal imaging of the limbs, carotid artery imaging, and brain imaging. Compared to traditional handheld ultrasound devices that primarily use reflected signals for image reconstruction, USCT systems use a large number of array elements around the imaging object, with reflected signals used for structural (reflection) image reconstruction and transmitted signals for functional (sound velocity and attenuation) image reconstruction.

[0003] Traditional handheld breast ultrasound examinations use a linear array probe placed close to the breast skin, using approximately 10ml of liquid gel coupling agent. The probe can be rotated and translated to provide multi-angle observation of breast tissue. The accuracy of the examination results depends on the physician's technique and experience. The prone scanning position for breast USCT is similar to that of breast MRI. USCT uses mechanical motion and a pre-designed scanning path to reconstruct multi-slice tomographic images or whole-breast 3D images, minimizing the impact of device operation on diagnostic results. At the same time, the clinical application of USCT systems also faces new challenges:

[0004] (1) Degassed water is usually used as the coupling medium. Each patient requires about 30 liters of pure warm water. The degassing, heating, filling, draining, and cleaning processes extend the entire scanning cycle and reduce patient throughput. Disposable use also wastes water resources.

[0005] (2) The state of the breast in the scanning room is uncertain. Deep breathing or slight movement of the breast during scanning may cause motion artifacts in USCT images;

[0006] (3) The shape and size of the breast vary from person to person. In the coronal plane, the breast is not an ideal circle and is often eccentrically located. In the sagittal and transverse planes, if the outer contour of the breast is not restricted, the ultrasound may propagate outside the imaging plane, and the transmission signal may be detected with a poor signal-to-noise ratio or cannot be detected, seriously affecting the image quality.

[0007] [Summary of the invention]

[0008] In response to the defects of the prior art, the purpose of the present invention is to provide a breast coupling fixation and shaping device and method for breast ultrasound imaging, aiming to solve the problem that the state of the breast in the scanning room of the existing breast USCT system is uncertain, and deep breathing or slight movement of the breast during the scanning process may cause motion artifacts in the USCT image.

[0009] To achieve the above-mentioned object, on the one hand, the present invention provides a breast coupling fixation and shaping device for breast ultrasound imaging, comprising: an SGCA outer ring coupling agent, an SGCA inner ring coupling agent, an inner ring support platform, and an outer ring support platform;

[0010] The inner diameter of the SGCA outer ring coupling agent is the same as the outer diameter of the SGCA inner ring coupling agent, and the SGCA outer ring coupling agent is located on the outside of the SGCA inner ring coupling agent; the inner ring support platform is located on the bottom side of the SGCA inner ring coupling agent; the outer ring support platform is located on the bottom side of the outer ring coupling agent; the outer diameter of the SGCA outer ring coupling agent is tightly fitted with the acoustic window of the annular array transducer; when the annular array transducer is used to scan the breast, the breast is located on the inner side of the SGCA inner ring coupling agent for coupling, fixation and shaping; the inner side of the SGCA inner ring coupling agent is divided into three areas, namely a hemisphere, a cone and a cylinder from top to bottom; the hemisphere is used to shape the chest wall area of ​​the breast; the cone is used to shape the middle part of the breast; the cylinder is used to shape the nipple and areola area of ​​the breast; the breast is shaped into a circle concentric with the annular array transducer on the coronal plane at each depth, limiting the slope of the breast skin sagging on the sagittal and transverse planes;

[0011] The inner ring support platform is used to support the SGCA inner ring coupling agent, and to pull the breast to be fixed and shaped in the SGCA inner ring coupling agent; the SGCA inner ring coupling agent and the SGCA outer ring coupling agent are used for coupling between the breast and the annular array transducer; the SGCA outer ring coupling agent is used to fill the gap between the SGCA inner ring coupling agent and the annular array transducer; the annular array transducer is used to perform ultrasonic scanning and imaging of the breast.

[0012] Further preferably, the gap between the SGCA outer ring coupling agent and the SGCA inner ring coupling agent is filled with pure water.

[0013] Further preferably, a liquid gel coupling agent or pure water lubrication is used to fill the gap between the acoustic window and the SGCA outer ring coupling agent;

[0014] Further preferably, the outer diameter of the SGCA outer ring coupling agent is consistent with the inner diameter of the acoustic window of the annular array transducer, and the outer diameter of the SGCA outer ring coupling agent is 180mm to 220mm, and the inner diameter of the optimally used annular array transducer is 220mm; the outer diameter of the inner ring coupling agent is related to the size of the breast to be scanned, and the outer diameter of the inner ring coupling agent is 120mm to 180mm, and is designed to be 150mm based on current clinical application experience; the height of the SGCA inner ring coupling agent and the SGCA outer ring coupling agent is higher than 100mm, and the height can be determined according to actual application.

[0015] Further preferably, the horizontal inclination angles of the starting slope and the ending slope of the hemisphere corresponding to the slope of the cone are 50° to 90°.

[0016] Further preferably, according to the morphology and size of the mammary gland, the SGCA inner ring coupling agent with different inner diameters is selected and replaced.

[0017] Further preferably, the inner ring support platform includes a negative pressure pumping hole, a negative pressure cavity and an anti-backflow negative pressure hole, which are used to attract the mammary gland to be fixed and shaped into the SGCA inner ring coupling agent by providing negative pressure.

[0018] On the other hand, based on the breast coupling fixation and shaping device provided above, the present invention provides a corresponding breast coupling fixation and shaping method for breast ultrasound imaging, comprising the following steps:

[0019] S1: Based on the size of the breast to be scanned, select the appropriate SGCA inner ring coupling agent and place it in the center of the scanning chamber;

[0020] S2: Place the breast to be scanned inside the inner ring of the SGCA coupling agent and guide the breast to be scanned to the center of the scanning area;

[0021] S3: The annular array transducer is moved up and down outside the SGCA outer ring coupling agent to perform an initial scan of the breast to be scanned, determining the coupling state between the breast to be scanned and the SGCA inner ring coupling agent, as well as the shape of the breast;

[0022] S4: Based on the coupling state between the breast and the SGCA inner ring coupling agent and the shape of the breast, the posture of the breast to be scanned is readjusted, and the scanning parameters and imaging parameters are determined.

[0023] Further preferably, water is added to the SGCA inner ring coupling agent both before and after S2 to ensure that there is no air between the breast to be scanned and the SGCA inner ring coupling agent.

[0024] Further preferably, in step S2, negative pressure is used to attract the breast to be scanned and fix it in the SGCA inner ring coupling agent.

[0025] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0026] The present invention provides a breast coupling, fixation and shaping device and method for breast ultrasound imaging, wherein the inner side of an SGCA inner ring coupling agent is divided into three areas, namely, a hemisphere, a cone and a cylinder from top to bottom; the hemisphere is used to shape the breast sphere; the cone is used to shape the middle part of the breast; and the cylinder is used to shape the nipple area of ​​the breast; the breast is shaped into a circle concentric with the annular array transducer on the coronal plane at each depth, and the slope of the breast skin sagging is limited on the sagittal plane and the transverse plane; during the scanning process, the entire breast is wrapped by the inner ring coupling agent, and the gap between the inner ring coupling agent and the breast is filled with a small amount of pure water (less than 50 ml) injected in advance. The slight negative pressure guides the nipple into the scanning center area, while also making the SGCA inner ring coupling agent fit the breast more closely, so that the breast is stabilized in the scanning center; the problem that slight movement of the scanning object will form motion artifacts on the image is solved, and the fixed or restricted placement area of ​​the scanning object reduces the motion artifacts of the image.

[0027] The present invention provides a breast coupling, fixation, and shaping device and method for breast ultrasound imaging. In the device, SGCA outer ring coupling agent and SGCA inner ring coupling agent are used instead of degassed water. Compared to using degassed water as a coupling medium (the degassing, heating, filling, draining, and cleaning processes prolong the entire scanning cycle and reduce patient throughput, and single-use is also a waste of water), the SGCA provided by the present invention is composed of purified water, glycerin, a moisturizer, and a preservative. These materials are environmentally friendly and degrade rapidly. They are in a solid gel state at room temperature, have a certain toughness, and can be manufactured uniformly and free of impurities. This can avoid the problems of pure water coupling agent heating and bubbles, and reduce preparation time before scanning.

[0028] The present invention provides a breast-coupled fixation and shaping device and method for breast ultrasound imaging, wherein the horizontal inclination angles corresponding to the starting and ending slopes of the hemisphere and the slope of the cone are 50° to 90°. According to Snell's law, the energy intensity of ultrasound energy penetrating the surface of the imaging object and entering the tissue is negatively correlated with the incident angle, while the deflection direction of ultrasound propagation is positively correlated with the incident angle. When the ultrasound propagation direction deviates too much, the ultrasound energy entering the tissue is low and deviates from the scanning plane, resulting in a low signal-to-noise ratio of the reflected and transmitted signals detected by the annular probe, affecting image reconstruction. Therefore, when the horizontal inclination angles corresponding to the starting and ending slopes of the hemisphere and the slope of the cone are 50° to 90°, the outer contour of the breast can be restricted in the sagittal and transverse planes, limiting the ultrasound incident angle to a range while ensuring that most of the intensity passes through the breast skin. Furthermore, the nipple region can be fixed in the center, facilitating accurate delineation of lesion location.

[0029] The present invention provides a breast coupling fixation shaping device and method for breast ultrasound imaging, wherein the breast is shaped into a circle concentric with the annular array transducer on the coronal plane at each depth. The propagation path of the coupling medium and the breast, including the deflection angle and propagation distance, can be kept consistent, and the outer contour of the breast can be predicted in advance, which is conducive to simplifying the imaging parameters.

Brief Description of the Drawings

[0030] FIG1 is a schematic diagram of the spatial position of a ring-shaped ultrasound probe and a breast when coupled with deaerated water according to an embodiment of the present invention;

[0031] FIG2( a ) is a schematic diagram showing the relationship between the deflection angle and the incident angle of ultrasound waves at the interface between the coupling medium and the breast skin according to an embodiment of the present invention;

[0032] FIG2( b ) is a schematic diagram showing the relationship between the intensity reflectivity and transmittance of ultrasound provided by an embodiment of the present invention;

[0033] FIG3( a ) is a three-dimensional model design diagram of an ultrasonic solid coupling agent provided in an embodiment of the present invention;

[0034] FIG3( b ) is a general design diagram of the inner ring of the ultrasonic solid coupling agent provided in an embodiment of the present invention;

[0035] FIG3( c ) is a detailed design diagram of the inner ring of the ultrasonic solid coupling agent provided in an embodiment of the present invention;

[0036] FIG4 is a breast pretreatment device provided by an embodiment of the present invention;

[0037] FIG5 is a schematic diagram of a breast scanning and breast shaping process using a solid coupling agent according to an embodiment of the present invention;

[0038] FIG6( a ) is a physical diagram of pure water coupling provided by an embodiment of the present invention;

[0039] FIG6( b ) is a physical diagram of a solid coupling agent coupling provided by an embodiment of the present invention;

[0040] FIG6( c ) is a physical diagram of a complete set of solid coupling agent molds provided in an embodiment of the present invention;

[0041] FIG7(a) is an ultrasound tomographic reflection image and three-dimensional three-view images of a breast without breast shaping using water coupling, provided by an embodiment of the present invention;

[0042] FIG7( b ) is an ultrasonic tomographic reflection image and three-dimensional three-view images after breast reshaping using solid coupling agent coupling according to an embodiment of the present invention;

[0043] FIG8( a ) is a tomographic image of the same breast before breast reshaping provided by an embodiment of the present invention;

[0044] FIG8( b ) is a three-dimensional image of the same breast before breast reshaping provided by an embodiment of the present invention;

[0045] FIG8( c ) is a tomographic image of the same breast after breast reshaping provided by an embodiment of the present invention;

[0046] FIG8( d ) is a three-dimensional image of the same breast after breast reshaping provided by an embodiment of the present invention;

[0047] FIG9 is a comparison diagram of the amplitude of the transmission image signal before and after shaping provided by an embodiment of the present invention. [Specific implementation method]

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0049] On one hand, the present invention provides a method and apparatus for coupling, fixing, and shaping the breast using ultrasonic solid gel coupling agent (SGCA). The method includes using SGCA instead of degassed water as a coupling agent for an ultrasonic tomography system, applying micro-negative pressure to guide the breast to the center of the scan area and fix it. By analyzing the propagation patterns of ultrasound in the ultrasonic tomography system, a breast shaping strategy using an SGCA inner ring coupling agent is proposed. Furthermore, an apparatus for achieving breast coupling, fixing, and shaping is designed, comprising an SGCA outer ring coupling agent, an SGCA inner ring coupling agent, a coupling agent support, and other accessories.

[0050] Using SGCA instead of deaerated water reduces pre-scan preparation time; negative pressure or other methods are used to guide the breast nipple to the middle scanning area and fix the entire breast; an SGCA inner ring coupling agent is provided to divide the breast into three areas, shaping the breast into a circle concentric with the annular array transducer on the coronal plane at each depth, and limiting the slope of the breast skin sagging on the sagittal and transverse planes to ensure that ultrasound can penetrate the breast skin with sufficient intensity and that the transmitted signal does not deviate from the scanning plane and can be well detected by the contralateral piezoelectric sensor;

[0051] Among them, the coronal plane is a plane that is defined by medicine and is a plane that divides the human body into two parts, front and back, along the height of the human body from top to bottom when the human body is standing.

[0052] Sagittal plane: The plane that divides the body into two parts along the front-back direction is called the sagittal plane;

[0053] Transverse plane: A plane parallel to the ground that divides the body into upper and lower parts.

[0054] Specific information about the device is as follows: The SGCA outer ring couplant is a cylindrical couplant ring with an outer diameter of 220 mm and an inner diameter of 150 mm. It is approximately 120 mm high and can be adjusted to suit the application. The SGCA inner ring couplant has an outer diameter of 150 mm and an inner diameter that is a combination of hemispheres, cones, cylinders, and other shapes designed based on shaping conditions. Specific details are shown in Table 1. The couplant support consists of a support platform for the outer ring couplant and a support platform for the inner ring couplant. The outer ring support platform is similar in shape to the outer ring couplant, while the inner ring support platform contains negative pressure pumping holes, a negative pressure cavity, and negative pressure holes for backflow prevention. The inner ring support platform can be adjusted to suit the height of the SGCA inner ring couplant. The outer diameter of the SGCA outer ring coupling agent fits tightly with the acoustic window of the annular array transducer. During scanning, the annular probe moves up and down to rub the SGCA outer ring coupling agent. Liquid gel coupling agent or pure water can usually be used for lubrication to fill the gap between the acoustic window and the SGCA outer ring coupling agent. The gap between the SGCA outer ring coupling agent and the SGCA inner ring coupling agent may be affected by the manufacturing process. In general, pure water is used to fill the gap between the two.

[0055] Table 1

[0056] The fixation and shaping of the mammary gland mainly relies on the negative pressure structure of the SGCA inner ring coupling agent and the inner ring support platform. Before scanning, a small amount of pure water needs to be poured into the SGCA inner ring coupling agent. Through the external negative pressure device, negative pressure is formed between the inner ring coupling agent and the mammary gland from the negative pressure pumping hole, negative pressure cavity, and anti-backflow negative pressure hole, so that the mammary gland is stretched downward and tightly fixed to the inner ring coupling agent.

[0057] On the other hand, based on the above-mentioned breast coupling, fixing and shaping device, the present invention provides a corresponding breast ultrasound tomography method, comprising the following steps:

[0058] Step 1: Before the volunteer lies on the scanning bed, clean the breast with a disposable wet towel to remove oil and sweat, keep the breast skin hydrophilic, measure the breast size, first place the SGCA outer ring coupling agent on the coupling agent support, select the SGCA inner ring coupling agent of similar size, and place the SGCA coupling agent in the center of the scanning chamber;

[0059] Step 2: Put a small amount of water into the SGCA inner ring coupling agent in advance to ensure that there is no air between the SGCA inner ring coupling agent and the breast skin;

[0060] Step 3: The volunteer lies prone on the examination table as instructed. The breast is placed in the SGCA inner ring coupling agent in the scanning chamber. The volunteer leans toward the breast scanning side and places the breast into the scanning chamber as much as possible while maintaining a comfortable prone position. The breast will be guided to the center of the scanning area. The nipple area is fixed in Zone III of the SGCA inner ring coupling agent.

[0061] Step 4: After the volunteer lies down comfortably and the negative pressure suction guides the breast to the correct position, an appropriate amount of pure water is injected into the scanning cavity to further couple and remove air;

[0062] Step 5: Perform a quick scan (pre-scan) of the entire breast to determine the coupling status between the breast and the SGCA inner ring coupling agent, as well as the shape of the breast;

[0063] Step 6: Use the pre-scan results to confirm whether the volunteer's prone position needs to be fine-tuned. A pre-scan takes about 20 seconds, and the average time to fine-tune the position based on the pre-scan results is about 1 minute.

[0064] Step 7: Determine the formal scanning and imaging parameters. Scanning parameters such as scanning depth and inter-slice spacing are set based on the results of the whole-breast pre-scan. More importantly, the acoustic parameters of different breast layers can also be roughly calculated and applied to the standard scan.

[0065] Step 8: Repeat the above steps to scan the other breast. The average time for scanning one breast is about 8 minutes, including pre-scan, fine-tuning the posture, and standard scan.

[0066] The technical solution of the present invention is described in detail below from the following three aspects:

[0067] First, the reasons why solid gel coupling agent replaces deaerated water are:

[0068] Deaerated water is a commonly used coupling medium. As shown in Figure 1, the acoustic window of the ring probe indirectly contacts the breast skin through the deaerated water, which has no effect on fixing or shaping the breast. Currently, each patient requires nearly 30 liters of deaerated water, which must be heated to a comfortable temperature in winter. Integrating defoaming and heating and insulation devices into the system increases system complexity and may pose safety issues for patients. Using an external exhaust heating device, the water processed in half an hour is barely enough for one person. Although water treatment and scanning can be performed in parallel, the defoaming, heating, filling, draining, and cleaning processes extend the entire scanning cycle and reduce patient throughput. Disposable water is also a waste of water.

[0069] Based on this, the present invention proposes a solid gel coupling agent (SGCA) as an alternative to deaerated water. SGCA is composed of purified water, glycerin, a moisturizer, and a preservative. These materials are environmentally friendly and degrade rapidly. The solid gel coupling agent has a similar ultrasound coupling effect to pure water and liquid gel coupling agents. It is in a solid gel state at room temperature, has a certain toughness, and can be made uniform and free of impurities, which can avoid the problems of pure water coupling agent heating and bubbles. The solid coupling agent can be made into a designed shape and is simple and easy to replace. Compared with the scanning water tank filling and draining process, the time consumed is greatly reduced. The acoustic parameters of SGCA were measured at room temperature (20°C). The propagation speed of ultrasound in SGCA is approximately 1485±2m / s, close to the propagation speed in water (1480±2m / s). After propagating the same distance (220mm), the amplitude of propagation in SGCA is 93.6% of that in water. At the same time, other indicators of SGCA also meet the medical standards for ultrasonic medical couplers.

[0070] Secondly, the control requirements of ultrasonic incident angle:

[0071] The law of ultrasonic reflection and transmission follows Snell's law. The energy intensity of ultrasonic waves penetrating the surface of the imaging object and entering the tissue is negatively correlated with the angle of incidence, and the deflection direction of ultrasonic propagation is positively correlated with the angle of incidence of the ultrasound. When the direction of ultrasonic propagation deviates too much, the ultrasonic energy entering the tissue is low and will deviate from the scanning plane. The signal-to-noise ratio of the reflected and transmitted signals detected by the annular probe is low, affecting image reconstruction. Figure 2(a) is a schematic diagram of the relationship between the deflection angle and the angle of incidence of ultrasonic waves at the interface between the coupling medium and the breast skin provided by an embodiment of the present invention; Figure 2(b) is a schematic diagram of the relationship between the intensity reflectivity and transmittance of ultrasonic waves provided by an embodiment of the present invention; combining Figures 2(a) and 2(b) can basically determine the conditions that the reshaped breast needs to meet in the sagittal and coronal planes.

[0072] The detailed explanation is as follows. The present invention analyzes the law of ultrasonic propagation in the probe of the annular array transducer. The Snell's law formula for ultrasonic propagation is:

[0073] Among them, θ i ,θ r and θ τ are the angle of incidence, angle of reflection, and angle of refraction respectively; c0 and c1 are the speed of sound of the coupling medium and the skin respectively; in general, the angle of incidence is equal to the angle of reflection, and the angle between the angle of incidence and the angle of reflection is 2θ i , the deflection angle of the ultrasonic propagation direction can be calculated as:

[0074] According to the law of conservation of energy, the energy reflection coefficient and transmission coefficient of ultrasound can be written as:

[0075] Where ρ0 and ρ1 are the densities of the coupling medium and the skin, respectively;

[0076] From the above formula and Figure 2(a), it is easy to infer that when the sound velocity of the coupling medium is equal to the sound velocity of the breast skin, ultrasonic propagation will not be deflected. The greater the difference in sound velocity between the coupling medium and the breast skin, the larger the deflection angle. The sound velocity and acoustic impedance of breast skin are actually slightly greater than those of pure water. When ultrasound reaches the skin, if the incident angle is too large, total reflection will occur. The sound velocity of breast skin varies from person to person, ranging from 1537 to 1720 m / s. The sound velocity of water can reach 1540 m / s at 50°C, which is too hot for human skin. In most cases, the sound velocity of water or other liquid gel coupling media is different from the sound velocity of breast skin at room temperature. The best solution to prevent acoustic wave deflection is to keep the sound velocity of the coupling medium and breast skin the same or nearly the same, but this is almost impossible to achieve in practical applications. When the sound velocity of the coupling medium is lower than that of the breast skin, which is closer to actual clinical application, the deflection angle increases with increasing incident angle, and increasing the sound velocity of the coupling medium can reduce the deflection angle.

[0077] When the coupling medium is pure water at 20°C, the speed of sound in water is approximately 1480 m / s. Figure 2(b) shows the effect of the ultrasonic incident angle on the deflection angle of ultrasonic waves penetrating breast skin. When the incident angle is less than 40°, the deflection angle is within 7°. Figure 2(b) shows that the reflection coefficient and transmission coefficient depend on the incident angle. When the incident angle is less than 40°, the transmission coefficient is above 87%. When the incident angle increases from 40° to 60°, the transmission coefficient drops sharply. If the incident angle exceeds 61.8°, the ultrasonic wave will be totally reflected from the surface of the breast skin, and the ultrasonic wave will not be able to enter the breast tissue. Therefore, after the coupling medium is determined, controlling the incident angle is an effective way to ensure high-intensity ultrasonic penetration of breast skin.

[0078] In the coronal plane, if the position of each transmitting array element is used as the origin of the view, the shape of the breast will be different; assuming that the breast tissue is homogeneous and isotropic, and the sound velocity of the breast tissue is the same as that of the coupling medium, the propagation direction of the transmitted wave will not be deflected in the coronal plane; when the ultrasound wave propagates directly to the opposite side along the diameter, the distance from the breast skin at different positions to the acoustic window is different, so the distance propagated in the coupling medium and breast tissue each time the ultrasound wave is transmitted is different, and the same conclusion applies to the propagation of ultrasound in other directions; in fact, the sound velocity of the breast tissue is different from that of the coupling medium, and not only the propagation velocity and propagation distance of the breast must be considered, but also the deflection angle, and the image reconstruction parameters need to be corrected according to the actual shape of the breast for each scan; under the simple model assumption, there are still some complex parameters that need to be optimized; if the breast contour is reshaped to be concentric with the annular transducer, the propagation path of the coupling medium and the breast, including the deflection angle and propagation distance, can be kept consistent, and the outer contour of the breast can be predicted in advance, which is conducive to simplifying the imaging parameters;

[0079] Ultrasound waves propagate in three dimensions and may propagate outside the imaging plane, so the deflection angle of ultrasound propagation must be very small in the sagittal and transverse planes. The conclusions for the sagittal and transverse planes are the same, taking the transverse plane as an example. The shape of the breast on the sagittal plane is shown in Figure 2(b), which shows that the slope of the skin contour changes with depth, so the incident angle is different at each depth. A tomographic image is a projection of an image of a certain thickness. Changing the slope of the breast skin may cause the thickness of the skin or other tissue in the reflected image to change. The incident angle that varies with depth also causes inconsistent ultrasound intensity propagating into the breast. The same breast tissue may have different grayscales, leading to misdiagnosis of lesions. When the ultrasound propagation direction deviates too much, it will deviate from the scanning plane, and the transmitted signal detected by the ring probe may have a low signal-to-noise ratio, resulting in a poor transmission image. If the outer contour of the breast can be restricted in the sagittal and transverse planes, the ultrasound incident angle can be limited to a certain range, ensuring that most of the intensity can pass through the breast skin. In addition, the nipple area can be fixed in the center area, which helps to accurately describe the location of the lesion.

[0080] Thirdly, the necessity of SGCA inner ring coupling agent:

[0081] Based on the above-mentioned requirements for the breast contour in the sagittal and transverse planes during the propagation of ultrasound, and the fact that slight movement of the scanned object will form motion artifacts in the image, fixing or restricting the placement area of ​​the scanned object can reduce the motion artifacts of the image; the scanning plane of the circular probe in the circular array transducer of ultrasonic tomography is fixed to the plane where the probe is located. For the circular probe that moves up and down, the ideal scanning object is a cylinder placed concentrically with the circular probe; the shape of the breast is very different from a cylinder and needs to be reshaped. The fingers, wrists, joints and other parts need to be fixed in position and placed in the middle of the scanning area; it is necessary to design relevant models for shaping according to the actual situation of the imaging object, and to design relevant usage methods and devices.

[0082] Figure 3(a) is a three-dimensional model design diagram of an ultrasonic solid couplant provided in an embodiment of the present invention; Figure 3(b) is an overall design diagram of the inner ring of the ultrasonic solid couplant provided in an embodiment of the present invention; Figure 3(c) is a detailed design diagram of the inner ring of the ultrasonic solid couplant provided in an embodiment of the present invention; Table 1 is a table of detailed dimensions of the inner ring of the ultrasonic solid couplant provided in an embodiment of the present invention;

[0083] A more detailed explanation is as follows:

[0084] Based on the size and shape of the breast, the SGCA inner ring coupling agent was proposed. The breast is divided into three regions, as shown in Figures 3(a) to 3(c). Region I is a part of the sphere close to the chest, Region III is a cylinder, which is the nipple area, and the rest is Region II, which is an area without a cone. These three regions are circles of different diameters on the coronal plane and are concentric with the ring probe at each coronal depth. and are the starting slope and ending slope of region I, respectively. is the slope of region II; by controlling the angle The incident angle of ultrasound can be controlled, and these horizontal tilt angles can be limited to 50°~90°, so that the incident angle is less than 40° in the sagittal and transverse planes. When ultrasound passes through the breast skin and reaches the internal tissue of the breast, the energy transmission coefficient of ultrasound is theoretically greater than 87%, and the deflection angle is less than 7°; in practical applications, the angle The angles are set at approximately 75°, 55°, and 60°, respectively. Zones I and II do not use 90° because the reflected waves from the breast skin will reflect multiple times between the probe acoustic window and the breast skin, resulting in multiple reflection artifacts on the reflected image. Zone III, where the effects of multiple reflections can be ignored, has a diameter of 40 mm and is used to guide the areola and secure the nipple. The detailed parameters of the SGCA mold are shown in Table 1. In clinical trials, the breast cannot be identical to the molded part; a small amount of water is required to remove air and fill the gap between the breast and the SGCA inner ring coupling agent.

[0085] The module is placed in the center of the scanning area. During the scanning process, the entire breast is wrapped by the SGCA inner ring coupling agent. The gap between the SGCA inner ring coupling agent and the mammary gland is filled with a small amount of pure water (less than 50ml) injected in advance. The slight negative pressure guides the nipple into the scanning center area, while also making the SGCA inner ring coupling agent fit the breast better and stabilize the breast in the scanning center.

[0086] The USCT system utilizes full-field echo information, reconstructing reflection images from reflected signals and transmission (acoustic velocity and attenuation) images from transmitted signals. Therefore, the signal-to-noise ratio of both reflected and transmitted signals is crucial for image reconstruction. Because the ideal imaging object for USCT is a cylinder, the reshaped breast should meet the following requirements:

[0087] a. The shape of the breast in the coronal plane is similar to a circle, and the coronal plane at each depth is concentric with the annular array transducer;

[0088] b. The slope of the breast skin contour in the sagittal and transverse planes should be limited to ensure that ultrasound can penetrate the breast skin with sufficient intensity and that the transmitted signal does not deviate from the scanning plane and can be well detected by the contralateral piezoelectric sensor;

[0089] c. The shape of the breast in the prone position is similar to an irregular cone or hemisphere. The reshaped breast can be a combination of hemispheres, cones, cylinders, etc., and is circular in the coronal plane. Placing the reshaped SGCA inner ring coupling agent at the center of the scan to fit the breast can well meet requirement a. Further analysis of the oblique incidence law of ultrasound can understand the deflection direction and propagation efficiency of ultrasound. By adjusting the slope of the SGCA inner ring coupling agent in the sagittal and transverse planes, the incident angle of ultrasound can be controlled.

[0090] Example

[0091] This embodiment provides a device for coupling, fixing, and shaping using a solid coupling agent, as shown in FIG4 , comprising: an SGCA outer ring coupling agent, an SGCA inner ring coupling agent, and a coupling agent support. FIG5 is a schematic diagram of the breast scanning and breast shaping process using a solid coupling agent according to an embodiment of the present invention. FIG6( a ) is a physical diagram of pure water coupling according to an embodiment of the present invention. FIG6( b ) is a physical diagram of solid coupling agent coupling according to an embodiment of the present invention. FIG6( c ) is a physical diagram of a complete set of solid coupling agent molds according to an embodiment of the present invention.

[0092] Based on the above settings, as shown in Figure 7(a), the ultrasound tomographic reflection image and three-dimensional three-view image of the breast without reshaping using water coupling are obtained; as shown in Figure 7(b), the ultrasound tomographic reflection image and three-dimensional three-view image of the breast after reshaping using solid coupling agent coupling are obtained. It can be clearly seen from Figure 7(a) that the unshaped breasts have different shapes, and the boundaries between breast skin, fat, and glands cannot be distinguished. The image performance of different areas of the same breast is also inconsistent, and a lack of continuity can be seen in the three-dimensional image. The image quality of the breast after reshaping in Figure 7(b) is significantly improved, and the shape is regular, and the breast tissue has obvious regularity in grayscale.

[0093] Figure 8(a) is a cross-sectional image of the same breast before reshaping provided by an embodiment of the present invention; Figure 8(b) is a three-dimensional image of the same breast before reshaping provided by an embodiment of the present invention; Figure 8(c) is a cross-sectional image of the same breast after reshaping provided by an embodiment of the present invention; Figure 8(d) is a three-dimensional image of the same breast after reshaping provided by an embodiment of the present invention; it can be seen that the reshaped breast can clearly diagnose breast lumps, while the unreshaped breast cannot see lumps. Figure 9 is a comparison diagram of the amplitude of the transmission image signal before and after reshaping provided by an embodiment of the present invention; Table 2 is a comparison table of the signal-to-noise ratio (SNR) of the transmission signal before and after reshaping provided by an embodiment of the present invention.

[0094] Table 2

[0095] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A breast coupling fixation and shaping device for breast ultrasound imaging, characterized in that: include: SGCA outer ring coupling agent, SGCA inner ring coupling agent, inner ring support table and outer ring support table; The inner diameter of the SGCA outer ring coupling agent is the same as the outer diameter of the SGCA inner ring coupling agent, and the SGCA outer ring coupling agent is located on the outside of the SGCA inner ring coupling agent; the inner ring support platform is located on the bottom side of the SGCA inner ring coupling agent; the outer ring support platform is located on the bottom side of the outer ring coupling agent; the outer diameter of the SGCA outer ring coupling agent is tightly fitted with the acoustic window of the annular array transducer; when the annular array transducer is used to scan the breast, the breast is located on the inner side of the SGCA inner ring coupling agent for coupling, fixation and shaping; the inner side of the SGCA inner ring coupling agent is divided into three areas, which are a hemisphere, a cone and a cylinder from top to bottom; the hemisphere is used to shape the chest wall area of ​​the breast; the cone is used to shape the middle part of the breast; the cylinder is used for the nipple and areola area of ​​the breast; the breast is shaped into a circle concentric with the annular array transducer on the coronal plane at each depth, and the slope of the sagging of the breast skin is limited on the sagittal plane and the transverse plane; The inner ring support platform is used to support the SGCA inner ring coupling agent, and to pull the breast to be fixed and shaped in the SGCA inner ring coupling agent; the SGCA inner ring coupling agent and the SGCA outer ring coupling agent are used for coupling between the breast and the annular array transducer; the SGCA outer ring coupling agent is used to fill the gap between the SGCA inner ring coupling agent and the annular array transducer; the annular array transducer is used to perform ultrasonic scanning and imaging of the breast.

2. The breast coupling fixation and shaping device according to claim 1, characterized in that: The gap between the SGCA outer ring coupling agent and the SGCA inner ring coupling agent is filled with pure water.

3. The breast coupling fixation and shaping device according to claim 1 or 2, characterized in that: Liquid gel coupling agent or pure water lubrication is used to fill the gap between the acoustic window and the SGCA outer ring coupling agent.

4. The breast coupling fixation and shaping device according to claim 1, characterized in that: The outer diameter of the SGCA inner ring coupling agent is 120 mm to 180 mm; the outer diameter of the SGCA outer ring coupling agent is 180 mm to 220 mm; the height of the SGCA inner ring coupling agent and the SGCA outer ring coupling agent is higher than 100 mm.

5. The breast coupling fixation and shaping device according to claim 1 or 4, characterized in that: The horizontal inclination angles corresponding to the starting slope and the ending slope of the hemisphere and the slope of the cone are 50° to 90°.

6. The breast coupling fixing and shaping device according to claim 1, characterized in that: According to the morphology and size of the mammary gland, choose to replace the SGCA inner ring coupling agent with different inner diameters.

7. The breast coupling fixation and shaping device according to claim 1 or 6, characterized in that: The inner ring support platform includes a negative pressure water pumping hole, a negative pressure cavity and an anti-backflow negative pressure hole, which are used to provide negative pressure to attract the mammary gland to be fixed and shaped into the SGCA inner ring coupling agent.

8. A breast coupling fixation and shaping method based on the breast coupling fixation and shaping device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Select the appropriate SGCA inner ring coupling agent based on the size of the breast to be scanned and place it in the center of the scanning chamber; S2: Place the breast to be scanned inside the inner ring coupling agent of SGCA and guide the breast to be scanned to the center of the scanning area; S3: The annular array transducer is moved up and down on the outside of the SGCA outer ring coupling agent to perform an initial scan of the breast to be scanned, and the coupling state between the breast to be scanned and the SGCA inner ring coupling agent and the shape of the breast are determined; S4: Based on the coupling state between the breast and the SGCA inner ring coupling agent and the shape of the breast, the posture of the breast to be scanned is readjusted, and the scanning parameters and imaging parameters are determined.

9. The breast coupling fixation shaping method according to claim 8, characterized in that: Water was added to the SGCA inner ring coupling agent before and after S2 to ensure that there was no air between the breast to be scanned and the SGCA inner ring coupling agent.

10. The breast coupling fixation shaping method according to claim 8 or 9, characterized in that: In step S2, negative pressure is used to attract the breast to be scanned and fix it in the inner ring coupling agent of SGCA.

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