Small animal CT (Computed Tomography) vascular motif and experimental preparation method

Abstract

The invention discloses a small animal CT blood vessel mold body and an experiment preparation method, the small animal CT blood vessel mold body comprises catheters, a main hollow tube and two rubber plugs, the two ends of the main hollow tube are each connected with one rubber plug in an inserted mode to seal the interior of the main hollow tube, and the catheters with different inner diameters are arranged in the main hollow tube; the two ends of the catheter penetrate through the adjacent rubber plugs respectively to extend to the outer side, and the designed blood vessel model body can simulate the structural characteristics of ultra-thin blood vessels under different parts in a small animal body and the distribution state of a contrast agent in the blood vessels; therefore, a controllable, standardized and repeatable angiography experimental platform is provided for calibration of a CT system, research and development of a novel contrast agent and design of a small animal angiography imaging scheme, the technical method is simple and easy to implement, and an important basis is provided for further development, application and popularization of an angiography technology.

Description

Technical Field

[0001] The present invention relates to the technical field of vascular disease research, and in particular to a small animal CT vascular phantom and an experimental preparation method thereof. Background Art

[0002] Vascular disease is one of the major issues threatening human health worldwide. As an imaging technology with high spatial resolution, fast imaging and easy operation, CT (computed tomography) has unique advantages in vascular imaging. By injecting high-attenuation contrast agents, the distribution of contrast agents in blood vessels can be carefully observed, and three-dimensional reconstruction of blood vessels can be achieved, providing a reliable basis for the detection of microvascular lesions in important areas such as cerebral blood vessels.

[0003] However, there are many limitations in current small animal experiments. Due to the small size of small animals, the diameter of their blood vessels is often only a few hundred microns to tens of microns. In addition, there are large differences in physiological structure and metabolic levels between individuals. After the contrast agent is injected into the blood vessels using traditional injection methods, the concentration of contrast agent in the blood vessels is difficult to accurately control and reproduce. Therefore, it is impossible to obtain a quantitative relationship between the injection dose and the minimum vascular diameter that the system can distinguish by accurately controlling the injection dose in the experiment, and it is also difficult to fully evaluate the vascular resolution limit of the CT system. This has restricted the further development and application promotion of vascular imaging technology to a certain extent.

[0004] Therefore, a new small animal CT vascular phantom and experimental preparation method are urgently needed to solve the above technical problems. Summary of the invention

[0005] The present invention aims to solve the above technical problems, namely, to solve the problem that in existing experiments, it is impossible to obtain a quantitative relationship between the injection dose and the minimum vascular diameter that the system can distinguish by accurately controlling the injection dose, and it is also difficult to comprehensively evaluate the vascular resolution limit of the CT system, which to a certain extent restricts the further development and application promotion of vascular imaging technology.

[0006] To this end, in a first aspect, the present invention provides a small animal CT vascular phantom, comprising a catheter, a main hollow tube and two rubber plugs, wherein a rubber plug is inserted at both ends of the main hollow tube to seal the interior of the main hollow tube, a plurality of catheters with different inner diameters are arranged in the main hollow tube, and the two ends of the catheters respectively penetrate through adjacent rubber plugs to extend to the outside.

[0007] In a specific embodiment of the above-mentioned small animal CT vascular phantom, the main hollow tube is made of PMMA material.

[0008] In a specific embodiment of the above-mentioned small animal CT vascular phantom, the material of the catheter is PE or PU.

[0009] In a specific implementation of the above-mentioned small animal CT vascular phantom, an additional hollow tube is sheathed on the outer side of the main hollow tube.

[0010] In a specific embodiment of the above-mentioned small animal CT vascular phantom, the small animal CT vascular phantom further includes a seal, and the seal is used to seal the port of the catheter.

[0011] In a specific embodiment of the above-mentioned small animal CT vascular phantom, the sealing member is a laryngeal clamp, a rubber pad is bonded to the inner wall of the laryngeal clamp, the outer walls of both ends of the main hollow tube are respectively covered with the laryngeal clamps, and the two ends of the catheter are respectively inserted between the rubber pad and the main hollow tube, so that the port of the catheter is sealed by tightening the laryngeal clamp to squeeze the rubber pad.

[0012] In a specific embodiment of the above-mentioned small animal CT vascular phantom, the sealing member is a clip, and the two ends of the catheter are respectively clamped with the clips to achieve sealing.

[0013] In a second aspect, the present invention further provides an experimental preparation method of a small animal CT vascular phantom as described in the first aspect, comprising an experimental tool, wherein the experimental tool comprises an extended needle, a rubber seat, a syringe and an injection needle, wherein the injection needle is mounted on the syringe, and the syringe is used to inject a contrast agent into a catheter. The experimental preparation method comprises the following steps: The extended needle is passed through the two rubber stoppers and the main hollow tube at the same time; Passing the catheter through the inside of the elongated needle, and then moving the elongated needle relative to the catheter to be pulled out from the rubber stopper and the main hollow tube; Inject liquid into the main hollow tube and seal it with two rubber stoppers; The injection needle is passed through the rubber seat, and one end of the catheter is inserted into the injection needle and extended to the needle plug of the injection needle, and then the injection needle is retracted so that the needle tip of the injection needle is inserted into the rubber seat; Injecting contrast medium into the catheter through an injection needle using a syringe; After the injection is completed, the two ends of the catheter are sealed.

[0014] In a specific embodiment of the experimental preparation method of the above-mentioned small animal CT vascular phantom, the small animal CT vascular phantom further includes a laryngeal clamp, a rubber pad is bonded to the inner wall of the laryngeal clamp, the outer walls of both ends of the main hollow tube are respectively covered with the laryngeal clamp, and the outer walls of both ends of the main hollow tube are respectively covered with the laryngeal clamp, and the step of "sealing the two ends of the catheter" specifically includes: The two ends of the conduit are respectively inserted between the adjacent rubber pad and the outer wall of the main hollow pipe, and then the throat clamp is controlled to tighten and squeeze the rubber pad to seal the port of the conduit.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The vascular phantom designed in the present invention can simulate the structural characteristics of extremely fine blood vessels in different parts of small animals, as well as the distribution state of contrast agents in blood vessels, thereby providing a controllable, standardized and repeatable vascular imaging experimental platform for the calibration of CT systems, the development of new contrast agents and the design of small animal vascular angiography imaging schemes. The technical method is simple and easy to implement, providing an important basis for the further development and application promotion of vascular imaging technology.

[0016] 2. The rubber seat designed by the present invention is used to insert the catheter into the injection needle before injecting the contrast agent into the catheter. Then, the port of the injection needle is inserted into the rubber seat to achieve sealing. In this way, the contrast agent is directly injected into the catheter through the syringe. In this way, the injection needle can be reused, and the catheter part inserted into the injection needle can also be reused, which reduces the experimental cost and saves resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which: Figure 1 It is a schematic diagram of the structure of the small animal CT vascular phantom provided by the present invention; Figure 2 It is a schematic diagram of the structure in which the catheter is installed through an extended needle; Figure 3 It is a schematic diagram of the structure in which the injection needle is inserted into the rubber seat; Figure 4 It is a schematic diagram of the structure of the clamp; Figure 5 It is a structural diagram of the throat hoop.

[0018] List of reference numerals: 1. Main hollow tube; 2. Rubber plug; 3. Catheter; 4. Additional hollow tube; 5. Extension needle; 6. Rubber seat; 7. Injection needle; 8. Clip; 9. Laryngeal clamp; 91. Rubber pad. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are used to define components, only for the convenience of distinguishing the above components, and unless otherwise stated, the above terms have no special meanings and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] The present invention relates to the field of vascular disease research technology, and in particular to a small animal CT vascular phantom and an experimental preparation method. The purpose is to solve the problem that in existing experiments, it is impossible to obtain a quantitative relationship between the injection dose and the minimum vascular diameter that can be distinguished by the system by accurately controlling the injection dose, and it is also difficult to comprehensively evaluate the vascular resolution limit of the CT system, which to a certain extent restricts the further development and application promotion of vascular imaging technology. To this end, the present invention provides a small animal CT vascular phantom and an experimental preparation method, comprising a catheter, a main hollow tube and two rubber plugs, wherein a rubber plug is inserted at both ends of the main hollow tube to seal the inside of the main hollow tube, a plurality of catheters with different inner diameters are arranged in the main hollow tube, and the two ends of the catheters respectively penetrate through adjacent rubber plugs to extend to the outside. The vascular phantom designed by the present invention can simulate the structural characteristics of extremely fine blood vessels at different parts of the small animal body, as well as the distribution state of contrast agents in the blood vessels, thereby providing a controllable, standardized and repeatable vascular imaging experimental platform for the calibration of CT systems, the development of new contrast agents and the design of small animal vascular angiography imaging schemes. The vascular phantom can be used to simulate the CT imaging effects of different blood vessel diameters at different parts of different imaging objects under different contrast agent concentrations. The technical method is simple and easy to implement, and provides an important basis for the further development and application promotion of vascular imaging technology.

[0023] The small animal CT vascular phantom and the experimental preparation method provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0024] See also Figure 1The present invention provides a small animal CT vascular phantom, comprising a catheter 3, a main hollow tube 1 and two rubber plugs 2, wherein a rubber plug 2 is inserted at both ends of the main hollow tube 1 to seal the inside of the main hollow tube 1, a plurality of catheters 3 with different inner diameters are arranged in the main hollow tube 1, and the two ends of the catheter 3 respectively penetrate through adjacent rubber plugs 2 to extend to the outside.

[0025] In the above embodiment, catheter 3 is used to simulate blood vessels in small animals. The density of catheter 3 should be close to that of biological soft tissue, and the attenuation of X-rays by the material of catheter 3 should be similar to that of biological tissue. The material of catheter 3 can be selected from polymer materials such as PE or PU. Multiple catheters 3 have different inner diameters, which can simulate the characteristics of fine blood vessels in different parts of different small animals, making the entire vascular model more widely used and more flexible. Regarding the inner diameter of catheter 3, this application does not make specific restrictions, for example, such as 20um, 50um, 100um, 200um.

[0026] In the above embodiment, the main hollow tube 1 is a cylinder, and the outer diameter of the main hollow tube 1 is close to the diameter of the imaging part of the simulated small animal, with a difference of 0-2 mm. The material density of the main hollow tube 1 should be close to the density of soft tissue, so, for example, the material of the main hollow tube 1 is PMMA. Different biological soft tissue components can be simulated by injecting different liquids into the main hollow tube 1 through a syringe.

[0027] In one embodiment, an additional hollow tube 4 is sleeved outside the main hollow tube 1, and the additional hollow tube 4 can be made of metal materials such as aluminum. The diameter and thickness of the additional hollow tube 4 can be adjusted, and can be used to simulate non-soft tissue materials of different organisms or different parts, such as bones.

[0028] In one embodiment, the small animal CT vascular phantom further includes a seal, which is used to seal the port of the catheter 3 .

[0029] There are several implementations regarding the specific structure of the seal.

[0030] The first implementation method is to refer to Figure 5 The sealing member is a throat hoop 9, a rubber pad 91 is bonded to the inner wall of the throat hoop 9, and throat hoop 9 is respectively sleeved on the outer walls of both ends of the main hollow tube 1. The two ends of the conduit 3 are respectively inserted between the rubber pad 91 and the main hollow tube 1, so that the port of the conduit 3 is sealed by tightening and squeezing the rubber pad 91 through the throat hoop 9. The throat hoop 9 contacts the conduit 3 through the rubber pad 91, which protects the conduit 3 and reduces the risk of the conduit 3 being damaged due to direct contact and squeezing with the throat hoop 9. In addition, the rubber pad 91 can be deformed under pressure to further block the port of the conduit 3 and play a sealing role. Since the throat hoop 9 can adjust the tightening force, the squeezing force can be adjusted, which is more conducive to ensuring the sealing effect.

[0031] In a second embodiment, the small animal CT vascular phantom further comprises two clamps 8, which are used to clamp the ends of the catheter 3 to achieve sealing. The structure of the clamps 8 is as follows: Figure 4 shown.

[0032] Since the diameter of the conduit 3 is small, the clamp 8 is used to directly clamp the end of the conduit 3. The extrusion force of this method is limited and cannot be adjusted. Therefore, in order to ensure the sealing effect, the end of the conduit 3 is sealed by a throat clamp 9 as a preferred embodiment of the present application.

[0033] In the prior art, in experiments on small animals, the contrast agent concentration in the blood vessels is uncertain after the injected contrast agent undergoes metabolic circulation in the animal body, and the blood vessel diameter is also uncertain. However, through the vascular phantom designed in this application, we can prepare various known concentrations of contrast agents in vitro and inject them into the catheter of the vascular phantom. The contrast agent concentration will naturally not be metabolized, that is, to achieve the purpose of precision and control. The known concentration of contrast agent can be used to calculate the amount of contrast agent injected in different small animal experiments, so that the quantitative relationship between the injection dose and the minimum vascular diameter that can be distinguished by the system can be obtained by accurately controlling the injection dose through the vascular phantom experiment. It provides an important basis for comprehensively evaluating the vascular resolution limit of the CT system, which is conducive to the development and application promotion of vascular imaging technology.

[0034] In another embodiment, see Figure 2-3 The present application also provides an experimental preparation method for a small animal CT vascular phantom, including an experimental tool, the experimental tool including an extended needle 5, a rubber seat 6, a syringe and an injection needle 7, the injection needle 7 is installed on the syringe, and the syringe is used to inject a contrast agent into a catheter 3. The experimental preparation method includes the following steps: S1, insert the extended needle 5 through the two rubber stoppers 2 and the main hollow tube 1 at the same time; S2, passing the catheter 3 through the inside of the extended needle 5, and then moving the extended needle 5 relative to the catheter 3 to be pulled out from the rubber stopper 2 and the main hollow tube 1; S3, injecting liquid into the main hollow tube 1 and sealing it through two rubber stoppers 2; the liquid is changed according to the different soft tissues simulated; S4, insert the injection needle 7 through the rubber seat 6, insert one end of the catheter 3 into the injection needle 7 and extend it to the needle plug of the injection needle 7, and then retract the injection needle 7 so that the needle port of the injection needle 7 is inserted into the rubber seat 6; S5, injecting contrast agent into the catheter 3 through the injection needle 7 using a syringe; S6, after the injection is completed, the two ends of the catheter 3 are sealed.

[0035] Since the catheter 3 has a small diameter and cannot pass through the rubber stopper 2 directly, steps S1-S2 are performed, and the extended needle 5 is used to first pass through the rubber stopper 2 and the main hollow tube 1, and then the catheter 3 is passed through the extended needle 5, and then the extended needle 5 is pulled out from the rubber stopper 2 and the main hollow tube 1. Due to the elasticity of the rubber stopper 2, the extended catheter 3 can be sealed with the catheter 3 after being pulled out. Repeat steps S1-S2 to install multiple catheters 3 with different inner diameters.

[0036] In step S4, the injection needle 7 is first passed through the rubber seat 6, and then the other end of the catheter 3 is passed through the injection needle 7 and extended into the needle plug, and then the injection needle 7 is withdrawn a little so that the needle tip stays in the rubber seat 6, so that the needle hole of the injection needle 7 can be closed, and when the contrast agent is injected through the syringe, the contrast agent can only enter the catheter 3. The present application unifies the injection method of the contrast agent, and the injection needle 7 and the catheter 3 of this injection method can be reused, saving costs.

[0037] In the above embodiment, preferably, the small animal CT vascular phantom further includes a throat clamp 9, a rubber pad 91 is bonded to the inner wall of the throat clamp 9, and throat clamps 9 are respectively sleeved on the outer walls of both ends of the main hollow tube 1. The step of "sealing the two ends of the catheter 3" specifically includes: The two ends of the conduit 3 are respectively inserted between the adjacent rubber pads 91 and the outer wall of the main hollow pipe 1 , and then the throat clamp 9 is controlled to tighten and squeeze the rubber pad 91 to seal the end of the conduit 3 .

[0038] The vascular phantom designed by the present invention can be installed with a variety of catheters with different inner diameters, and the main hollow tube and the additional hollow tube can be used to simulate the structural characteristics of very fine blood vessels in different parts of small animals. By customizing the contrast agent concentration and injecting it into the catheter, the distribution of the contrast agent in the blood vessel can be simulated. Finally, by performing CT imaging and reconstruction on the vascular phantom, the imaging effect of catheters with different inner diameters under different concentrations of contrast agents can be observed, so as to obtain the relationship between the intravascular contrast agent concentration and the system's vascular resolution ability, solving the problem in existing experiments that the quantitative relationship between the minimum vascular diameter that can be resolved by the system cannot be obtained by accurately controlling the injection dose. It also provides an experimental platform for the development of more lasting contrast effects and lower doses of contrast agents.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A small animal CT vascular phantom, characterized in that: It includes a catheter, a main hollow tube and two rubber plugs. One rubber plug is inserted at both ends of the main hollow tube to seal the inside of the main hollow tube. A plurality of catheters with different inner diameters are arranged in the main hollow tube, and the two ends of the catheters respectively penetrate the adjacent rubber plugs to extend to the outside.

2. The small animal CT vascular phantom according to claim 1, characterized in that: The main hollow tube is made of PMMA.

3. The small animal CT vascular phantom according to claim 1, characterized in that: The material of the catheter is PE or PU.

4. The small animal CT vascular phantom according to claim 1, characterized in that: An additional hollow tube is sleeved on the outer side of the main hollow tube.

5. The small animal CT vascular phantom according to claim 1, characterized in that: The small animal CT vascular phantom further includes a seal, which is used to seal the port of the catheter.

6. The small animal CT vascular phantom according to claim 5, characterized in that: The sealing member is a throat clamp, a rubber pad is bonded to the inner wall of the throat clamp, the throat clamps are respectively sleeved on the outer walls of both ends of the main hollow tube, and the two ends of the conduit are respectively inserted between the rubber pad and the main hollow tube, so that the port of the conduit is sealed by tightening the throat clamp to squeeze the rubber pad.

7. The small animal CT vascular phantom according to claim 5, characterized in that: The sealing member is a clip, and the two ends of the catheter are respectively clamped with the clips to achieve sealing.

8. An experimental preparation method of a small animal CT vascular phantom according to any one of claims 1 to 7, characterized in that: The experimental tool comprises an extended needle, a rubber seat, a syringe and an injection needle, wherein the injection needle is mounted on the syringe, and the syringe is used to inject a contrast agent into a catheter. The experimental preparation method comprises the following steps: The extended needle is passed through the two rubber stoppers and the main hollow tube at the same time; Passing the catheter through the inside of the elongated needle, and then moving the elongated needle relative to the catheter to be pulled out from the rubber stopper and the main hollow tube; Inject liquid into the main hollow tube and seal it with two rubber stoppers; The injection needle is passed through the rubber seat, and one end of the catheter is inserted into the injection needle and extended to the needle plug of the injection needle, and then the injection needle is retracted so that the needle tip of the injection needle is inserted into the rubber seat; Injecting contrast medium into the catheter through an injection needle using a syringe; After the injection is completed, the two ends of the catheter are sealed.

9. The experimental preparation method of the small animal CT vascular phantom according to claim 8, characterized in that: The small animal CT vascular phantom further comprises a laryngeal clamp, a rubber pad is bonded to the inner wall of the laryngeal clamp, the outer walls of both ends of the main hollow tube are respectively covered with the laryngeal clamp, and the outer walls of both ends of the main hollow tube are respectively covered with the laryngeal clamp, and the step of "sealing the two ends of the catheter" specifically comprises: The two ends of the conduit are respectively inserted between the adjacent rubber pad and the outer wall of the main hollow pipe, and then the throat clamp is controlled to tighten and squeeze the rubber pad to seal the port of the conduit.

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