CN110755113A

CN110755113A - Tissue-imitated phantom for detecting three-dimensional imaging performance of ultrasonic tomography equipment

Info

Publication number: CN110755113A
Application number: CN201911242655.9A
Authority: CN
Inventors: 张迪; 牛凤岐; 朱承纲; 程洋
Original assignee: Institute of Acoustics CAS
Current assignee: Institute of Acoustics CAS
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-02-07

Abstract

The invention discloses a tissue phantom for detecting three-dimensional imaging performance of an ultrasonic tomography device, which is in a round table shape and comprises: a phantom shell, an acoustic window (3), a support plate (6), a background tissue imitating material (14) and a plurality of oval target bodies; the phantom shell is formed by fixedly connecting an upper panel (2), a lower panel (13) and a supporting plate (10), the phantom shell and an acoustic window (3) stuck to the side surface of the circular truncated cone form a closed space, a background tissue imitation material (14) is filled in the closed space, and a plurality of oval target bodies are embedded in the closed space; an inlet for filling a background tissue-imitating material (14) is formed in the supporting plate (10), and a plugging rubber is attached to the inlet; and a supporting and protecting plate (6) is fixed outside the supporting plate (10). The tissue-imitated body model can be used for detecting and evaluating the three-dimensional imaging performance of the ultrasonic tomography equipment.

Description

Tissue-imitated phantom for detecting three-dimensional imaging performance of ultrasonic tomography equipment

Technical Field

The invention belongs to the field of quality detection of medical instruments, and particularly relates to a tissue-imitated body model for detecting three-dimensional imaging performance of ultrasonic tomography equipment.

Background

B-ultrasonic and X-CT, magnetic resonance imaging, nuclear medicine imaging are the four most practical diagnostic imaging techniques in the present day, and B-ultrasonic is the top of the four in terms of popularity. Particularly under specific conditions in China, the B-mode ultrasound technology is not only used for routine diagnosis of various diseases, but also is generally used in the fields of birth control, eugenics and reproductive health. The performance and quality of the Chinese characters are related to economic benefits of manufacturers and hospitals, and the health and the welfare of the whole Chinese nation including offspring and offspring are affected. In view of this, the national authorities have established and released the corresponding technical standards as legal compliance for their life-long quality supervision.

In clinic, doctors make diagnosis according to the information provided by the ultrasonic scanning sonogram, so the image quality is considered as the primary factor for measuring the quality of the B-ultrasonic product and judging whether the B-ultrasonic works normally or not. According to international consensus, the technical indicators (i.e. performance) characterizing the image quality include dead zone, depth of detection, axial (longitudinal) resolution, lateral (transverse) resolution, pitch resolution, contrast resolution, and geometric errors of display and measurement, etc. The material technical means which can make objective, rapid, vivid and quantitative evaluation on the performance and quality of the B ultrasonic equipment in all links of development, production, sale, use, maintenance and legal management (quality supervision and inspection, metrological verification, import and export commodity inspection) of the B ultrasonic equipment only has an imitated tissue ultrasonic phantom. An ultrasonic Tissue simulation Phantom is translated from English Tissue simulation ultrasonic Phantom, namely a human physical model simulating soft Tissue in the aspect of ultrasonic propagation characteristics, and is a passive testing device which is composed of an ultrasonic Tissue simulation material (TM material for short), a plurality of testing targets embedded in the material, an acoustic window, a shell, an indicating decoration panel and the like. The tissue-imitated ultrasonic body model is specified equipment for executing national technical standards and metrological verification procedures, and has the characteristics of a standard device.

With the development of electronic technology and biomedical engineering, more and more medical ultrasonic-based diagnosis and treatment methods and equipment appear. Such as ultrasonic computed tomography (USCT), which is a promising technique for early breast tumor detection and diagnosis. The technology scans and images the mammary gland in a water tank through a ring array ultrasonic transducer, and the imaging modes comprise a B ultrasonic mode using ultrasonic reflected wave signals, an acoustic velocity measurement imaging mode using transmitted wave signals and an acoustic attenuation mode. The ultrasonic scanning tomography can be realized in various ways, such as forming a series of tomography images through longitudinal mechanical scanning of an annular array, forming tomography images after mechanical scanning of a plurality of pairs of transducers and spatial sampling, or performing electronic scanning tomography by using a spatial semi-ellipsoidal array transducer. The ultrasonic tomography device generally uses deaerated water as a coupling medium between a transducer and a human body, is mainly used for three-dimensional ultrasonic scanning imaging of breasts, and can also be used for tomography imaging of limbs and other parts.

All of the meters used for quality testing are periodically certified or calibrated as required by the medical instrument manufacturing industry and professional quality testing agencies quality systems. The tissue-imitated ultrasonic phantom belongs to a tissue substitute and is not a measuring instrument, a standard device in the sense of metrology does not exist, and the metrological verification or calibration cannot be implemented, but a rule of regular detection and comparison is formed from the end of the last century because the quality of ultrasonic diagnostic equipment is directly influenced, and the rule is accepted and followed by related fields. As an ultrasonic tomography imaging device of a medical instrument, a tissue-imitated phantom is supposed to be used for imaging performance and quality inspection. At present, aiming at the new ultrasonic imaging diagnostic equipment of USCT, the current tissue-imitating body model is no longer suitable for detecting the performance of the USCT.

Disclosure of Invention

The invention aims to overcome the technical defects and provides a tissue-imitated body model for detecting the three-dimensional imaging performance of an ultrasonic tomography device, which can be specially used for inspecting the three-dimensional imaging performance of the ultrasonic tomography device and is an ultrasonic passive device.

In order to achieve the above object, the present invention provides a tissue phantom for detecting three-dimensional imaging performance of an ultrasonic tomography apparatus, wherein the tissue phantom is in a circular truncated cone shape, and comprises: a phantom shell, an acoustic window, a support guard plate and a background tissue-imitating material; the phantom shell is formed by fixedly connecting an upper panel, a lower panel and a supporting plate, the phantom shell and an acoustic window stuck to the side surface of the circular truncated cone form a closed space, background tissue imitating materials are filled in the closed space, and a plurality of oval target bodies are embedded in the closed space; an inlet filled with a background tissue-imitating material is formed in the supporting plate, a plugging rubber is attached to the inlet, and a supporting plate is fixed outside the supporting plate.

As an improvement of the device, the phantom housing and the supporting plate are made of hard structural plastics.

As an improvement of the device, the sound window adopts a polyester film with the thickness of 50-100 mu m.

As an improvement of the device, the acoustic window is connected with the upper panel, the lower panel and the supporting plate, and the included angle between the tangent plane of the acoustic window and the lower panel ranges from 60 degrees to 90 degrees.

As a modification of the above device, a first support column and a second support column are arranged between the upper panel and the lower panel; the first support column is sleeved with a first sound absorption sleeve, the second support column is sleeved with a second sound absorption sleeve, and the first sound absorption sleeve and the second sound absorption sleeve are made of sound absorption materials.

As an improvement of the device, the inlet on the supporting plate comprises a first round hole and a second round hole which are respectively blocked by a first blocking rubber and a second blocking rubber, and the first blocking rubber and the second blocking rubber are both made of vacuum rubbers.

As an improvement of the device, the background tissue-imitating material is a water-based polymer gel-based composite material; the background tissue-imitating material is maintained through maintenance liquid, and the maintenance liquid is injected through the first plugging rubber and the second plugging rubber.

As an improvement of the device, the oval lump target body comprises a large oval body and a small oval body, and the materials of the oval lump target body are aqueous polymer gel basesThe volume range of the large ovoid is 30-200 cm³The volume range of the small ovoid is 2-30cm³(ii) a The oval target body can be maintained by using special maintenance liquid.

As an improvement of the device, the large ovoid and the small ovoid are arranged between the upper panel and the lower panel, and the projection positions and the shape marks of the large ovoid and the small ovoid embedded in the background imitated tissue material are drawn on the outer surfaces of the upper panel and the lower panel.

As an improvement of the device, the supporting plate is provided with two countersunk head screw holes, the supporting plate is correspondingly provided with two countersunk head screw holes, and the supporting plate are fixed together through a first fixing bolt and a second fixing bolt.

The invention has the advantages that:

1. compared with the prior similar products, the tissue-imitated phantom designed and manufactured according to the invention is specially used for detecting the three-dimensional imaging performance of the ultrasonic tomography equipment and evaluating the three-dimensional discovery and measurement capability of the focus;

2. the invention can detect and measure the three-dimensional imaging performance of the ultrasonic tomography imaging equipment for scanning and imaging the annular array in different circumferential directions by the distribution design of the ovoid targets;

3. according to the invention, the oval target with a specified size and volume is embedded in the tissue-imitating material, so that quality detection, guarantee measurement and performance evaluation can be carried out on the three-dimensional imaging capability and the three-dimensional target image volume quantitative measurement capability of the equipment;

4. by the design of the inclined plane sound window, the invention avoids the false image caused by multiple reflections between the transducer and the sound window;

5. the tissue-imitating body model has original maintainability, and the service life of the body model can be greatly prolonged by regular maintenance and injection maintenance.

Drawings

FIG. 1 is a side external view of a tissue phantom simulated for three-dimensional imaging performance detection of an ultrasonic tomography device according to the invention;

FIG. 2 is a perspective view of the inside of an acoustic window of a phantom of tissue of the present invention for three-dimensional imaging performance testing of an ultrasonic tomography device;

FIG. 3 is a side sectional view of a phantom of the invention used for three-dimensional imaging performance testing of an ultrasonic tomography device;

fig. 4 is a schematic diagram of a tissue phantom simulated embodiment for detecting the three-dimensional imaging performance of the ultrasonic tomography device.

Reference numerals:

1. tissue phantom 2, upper panel 3 and acoustic window

6. Supporting and protecting plate 10, supporting plate 11 and small egg-shaped body

12. Large ovoid 13, lower panel 14, background tissue-imitating material

15. Annular array transducer 51, first support column 52, second support column

61. First round hole 62, second round hole 71, first fixing bolt

72. Second fixing bolt 81, first plugging rubber 82 and second plugging rubber

91. First sound-absorbing sleeve 92, second sound-absorbing sleeve

Detailed Description

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

All of the meters used for quality testing are periodically certified or calibrated as required by the medical instrument manufacturing industry and professional quality testing agencies quality systems. The ultrasonic tissue-imitating body model belongs to a tissue substitute, and has formed a rule of regular detection and comparison from the end of the last century because the ultrasonic tissue-imitating body model directly influences the judgment on whether the quality of ultrasonic diagnostic equipment is qualified or not, and is recognized and followed by various related fields. The product corresponding to the invention is used for quality detection and evaluation of the ultrasonic tomography equipment, and is used for three-dimensional imaging volume calibration and imaging performance detection of the ultrasonic imaging equipment.

The tissue-imitating body model is used specially for detecting and evaluating the comprehensive imaging performance and focus discovering ability of ultrasonic tomography imaging equipment and is one passive ultrasonic device for ensuring the quality of medical ultrasonic equipment. Ultrasonic computed tomography (USCT) generally uses a ring array ultrasonic transducer to scan and image a human body (such as breast) in a water tank, and the imaging modes include a B-mode using ultrasonic reflected wave signals, a sound velocity measurement imaging mode using transmitted wave signals, and an acoustic attenuation mode. The ultrasonic scanning tomography can be realized in various ways, such as forming a series of tomography images through longitudinal mechanical scanning of an annular array, forming tomography images after mechanical scanning of a plurality of pairs of transducers and spatial sampling, or performing electronic scanning tomography by using a spatial semi-ellipsoidal array transducer. The ultrasonic tomography device generally uses deaerated water as a coupling medium between a transducer and a human body, is mainly used for three-dimensional ultrasonic scanning imaging detection of breasts, and can also be used for tomography imaging of limbs and other parts.

As shown in fig. 1 and fig. 2, the invention provides a tissue phantom for detecting three-dimensional imaging performance of an ultrasonic tomography device, wherein the tissue phantom 1 is in a circular truncated cone shape and comprises: a phantom housing, an acoustic window 3, a support plate 6, a background tissue-mimicking material 14, and a plurality of ovoid target bodies. The phantom shell consists of an upper panel 2, a lower panel 13, a first supporting column 51, a second supporting column 52 and a supporting plate 10, and the phantom shell and the supporting plate 6 are made of hard structural plastics; preferably, the rigid structural plastic is organic glass (PMMA, chemical name is polymethyl methacrylate) material, and may be other structural plastics, such as ABS acrylonitrile-butadiene-styrene terpolymer, polyvinyl chloride plastic, and the like. The upper panel 2 and the lower panel 13 form the upper and lower surfaces of the circular truncated cone shape. The phantom shell is formed by gluing an upper panel 2, a lower panel 13, a first supporting column 51, a second supporting column 52 and a supporting plate 10, a closed space is formed together with a sound window 3 formed by the side surface, a background-simulating Tissue Material (TMM) 14 is filled in the closed space, the sound window 3 is connected with the upper panel 2, the lower panel 13 and the supporting plate 10, and the included angle range between the section of the sound window 3 and the lower panel 13 is 60-90 degrees. The angle is determined by the distance of the acoustic window 3 from the transducer surface and the longitudinal dimension of the transducer, the angle being such that multiple reflections between the acoustic window 3 and the transducer are avoided. The first and

second support columns

51 and 52 are sleeved with first and second sound-absorbing

sleeves

91 and 92, and the materials are sound-absorbing materials for absorbing incident sound waves to avoid multiple reflection artifacts caused by reflected sound waves. The corresponding positions and sizes of the large ovoid 12 and the small ovoid 11 embedded in the background tissue-imitating material 14 are marked on the outer sides of the upper panel 2 and the lower panel 13. The acoustic window 3 is made of a polyester film material with the thickness of 50-100 mu m and is used for simulating the acoustic characteristics of human epidermal tissues.

The background tissue-imitating material 14 is a material for imitating acoustic parameters of human soft tissues, the material is a water-based polymer gel matrix composite material, the sound velocity of the ultrasonic tissue-imitating material (TMM) is (1540 +/-10) m/s, the slope of the sound attenuation coefficient of the ultrasonic tissue-imitating (TM) material is (0.7 +/-0.05) dB/(cm.MHz), and the tissue-imitating material parameters are all temperature of [ (23 +/-3) DEG C]The obtained value was measured under the conditions of (1). The target body of the ovoid comprises a large ovoid 12 and a small ovoid 11, and the volume range of the large ovoid 12 is (30-200 cm)³) The volume range of the small ovoid 11 is (2-30 cm)³) Accurate calibration volume V of ovoid₀And the dimensions of the long and short axes are accurately measured and given as phantom parameters. The ovoid has the same acoustic attenuation and acoustic velocity as the background mock tissue material, the ovoid acoustic velocity: (1540. + -.10) m/s (23 ℃ C. + -3 ℃ C.), slope of acoustic attenuation coefficient: 0.70 +/-0.05 dB/cm/MHz (23 +/-3 ℃), but the ovoid target and the background tissue-imitating material have different backscattering, so that the ovoid target and the background tissue-imitating material can be displayed as an imaging area with gray scale contrast with the background tissue-imitating material in a B-ultrasonic imaging instrument.

As shown in FIG. 2, the large and

small ovoids

12 and 11 embedded within the background mock tissue material 14 are preferably placed at different depths to be staggered on the ultrasound image to avoid occlusion. To make full use of space, the two ovoids are preferably placed in an intermediate position between the upper and

lower plates

2, 13, as far away from the upper and

lower plates

2, 13 as possible.

As shown in fig. 3. The support plate 10 serves to support and hold the phantom steady to the tissue phantom. The supporting plate 10 is formed with a first circular hole 61 and a second circular hole 62 for passage of the tissue-mimicking material 14. The two round holes are sealed by a first sealing rubber 81 and a second sealing rubber 82 which are adhered with excellent elasticity, and the round holes are used as liquid injection and air suction inlets during the maintenance of the imitated tissue material.

Two countersunk head screw holes are formed in the supporting plate 6, two identical countersunk head screw holes are formed in the corresponding positions of the supporting plate 10, the first fixing bolt 71 penetrates through one countersunk head screw hole of the supporting plate 6 and the corresponding countersunk head screw hole in the supporting plate 10, the second fixing bolt 72 penetrates through the other countersunk head screw hole of the supporting plate 6 and the corresponding countersunk head screw hole in the supporting plate 10, and therefore the supporting plate 6 and the supporting plate 10 are fixed together.

The tissue-imitating material 14 is a core part of the ultrasonic phantom, and the functional failure is caused by the variation of the composition, the state and the acoustic characteristics of the tissue-imitating material, the tissue-imitating material of the ultrasonic tissue-imitating phantom has maintainability, liquid contained in the tissue-imitating material can be evaporated and lost through gaps of a shell of the phantom, the tissue-imitating material can lose water and shrink after the phantom is used for a long time, and the phantom can be completely failed and cannot be recovered under the condition of severe water loss. The tissue-imitating material can be maintained daily by using an aqueous maintenance solution, and the aqueous maintenance solution can be injected by using an injection needle through a first plugging rubber 81 and a second plugging rubber 82 at the bottom; the aqueous maintenance liquid is specially prepared for the tissue-imitating material. The daily maintenance period is related to the temperature and humidity environment of the phantom. The service life of the phantom can be greatly prolonged by daily supplementing and maintaining liquid for maintenance.

Fig. 4 is a schematic diagram of the tissue phantom used for detecting the imaging performance of an ultrasonic tomography imaging device, and the whole structure is in a closed or semi-closed water tank, and degassing treatment is usually required. The device in the embodiment uses a circular array transducer 15, i.e. the transducer is arranged in a partial or full circular arc. The phantom 1 is placed in water, typically with the lower panel 13 placed on a horizontal platform submerged in water. It is often necessary to have the water level of the water bath for ultrasonic coupling higher than the top panel of the phantom. The center of the phantom is ensured to coincide with the center of the transducer, and measures are taken to remove bubbles attached to the acoustic window. Starting imaging equipment, setting the imaging equipment in a transmitting-receiving state of all array elements, adjusting the upper and lower positions of an ultrasonic probe, and enabling a radiation surface to be aligned with a phantom acoustic window to obtain a two-dimensional image of a material and a structure in a phantom;

switching the imaging device to a three-dimensional (3D) imaging function, acquiring and storing a plurality of two-dimensional images, then performing three-dimensional reconstruction and measuring the volume of the ovoid target;

if the volume of some oval target measured by the instrument is v, the calibration value of the target volume is v₀Then the volumetric measurement error is:

|(v－v₀)/v₀|×100％

after the test, the mold is taken out of the water and the surface is wiped off with a soft towel or the like.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The utility model provides a imitative tissue phantom that is used for three-dimensional imaging performance of ultrasonic tomography equipment to detect which characterized in that, imitative tissue phantom is round platform form, includes: a phantom shell, an acoustic window (3), a support plate (6), a background tissue imitating material (14) and a plurality of oval target bodies; the phantom shell is formed by fixedly connecting an upper panel (2), a lower panel (13) and a supporting plate (10), the phantom shell and an acoustic window (3) stuck to the side surface of the circular truncated cone form a closed space, a background tissue imitation material (14) is filled in the closed space, and a plurality of oval target bodies are embedded in the closed space; an inlet for filling a background tissue-imitating material (14) is formed in the supporting plate (10), and a plugging rubber is attached to the inlet; and a supporting and protecting plate (6) is fixed outside the supporting plate (10).

2. The tissue phantom according to claim 1, wherein the phantom housing and the support plate (6) are both made of rigid structural plastic.

3. The phantom according to claim 1, wherein the acoustic window (3) is a 50-100 μm thick polyester film.

4. The tissue-mimicking phantom according to claim 3, wherein the acoustic window (3) is connected to the upper panel (2), the lower panel (13) and the support plate (10), and an angle between a tangent plane of the acoustic window (3) and the lower panel (13) is in a range of 60 ° to 90 °.

5. The tissue phantom according to claim 1, characterized in that a first support column (51) and a second support column (52) are provided between the upper panel (2) and the lower panel (13); the first support column (51) is sleeved with a first sound absorption sleeve (91), the second support column (52) is sleeved with a second sound absorption sleeve (92), and the first sound absorption sleeve (91) and the second sound absorption sleeve (92) are made of sound absorption materials.

6. The tissue phantom according to claim 1, wherein the inlet of the support plate (10) comprises a first round hole (61) and a second round hole (62) which are respectively blocked by a first blocking rubber (81) and a second blocking rubber (82), and the first blocking rubber (81) and the second blocking rubber (82) are made of vacuum rubber.

7. The tissue phantom according to claim 6, wherein the background tissue mimicking material (14) is an aqueous polymer gel-based composite; the background tissue imitating material (14) is maintained by maintenance liquid, and the maintenance liquid is injected by a first plugging rubber (81) and a second plugging rubber (82).

8. The tissue-mimicking phantom according to claim 1, wherein the ovoid target comprises a large ovoid (12) and a small ovoid (11), the materials of the ovoid target are aqueous polymer gel-based composite materials, and the volume of the large ovoid (12) ranges from 30cm to 200cm³The volume range of the small ovoid (11) is 2-30cm³(ii) a The ovoid target bodyThe maintenance can be performed by using a special maintenance liquid.

9. The phantom according to claim 8, characterized in that the large ovoid (12) and the small ovoid (11) are arranged between the upper panel (2) and the lower panel (13), and the outer surfaces of the upper panel (2) and the lower panel (13) are painted with the projected position and the outline of the large ovoid (12) and the small ovoid (11) embedded in the background phantom material (14).

10. The tissue phantom according to claim 1, wherein the supporting plate (6) is provided with two countersunk screw holes, the supporting plate (10) is correspondingly provided with two countersunk screw holes, and the supporting plate (10) and the supporting plate (6) are fixed together through a first fixing bolt (71) and a second fixing bolt (72).