CN110353720B - Synchrotron radiation X-ray micro CT and fixing device for living body imaging of small animal limbs - Google Patents

Abstract

The utility model provides a synchrotron radiation X-ray micro CT and fixing device suitable for little animal four limbs live body formation of image, fixing device is including being used for placing the objective table of little animal after anesthesia, fix stand and the lid dress on the objective table, with objective table top and the confined plumbous lid all around, synchrotron radiation light source includes fixing device, fixing device's objective table fixes on the rotatory sample stage of synchrotron radiation X-ray micro CT, and sleeve axle center and rotatory sample stage rotation axle center coaxial setting on the objective table, this fixing device of device can wholly and locally fix living animal, can avoid the trunk position outside the four limbs joint to receive the influence of high-dose ray simultaneously, and the survival of the living animal of maximum protection is convenient for carry out long-term animal experiment.

Description

Synchrotron radiation X-ray micro-CT and fixation device for live imaging of limbs of small animals

technical field

The invention relates to a synchrotron radiation X-ray micro-CT and a fixing device suitable for live imaging of limbs of small animals.

Background technique

Sports injuries have the characteristics of high recurrence rate and difficult regeneration and repair. They mainly occur in the bones and joints of the extremities, often accompanied by soft tissue injuries. Imaging evaluation is an important means to study the healing of limb injuries in small animals. At present, commonly used imaging methods include microCT, MRI, etc., but limited by the spatial resolution, it is difficult for conventional methods to achieve three-dimensional imaging at ultra-high resolution.

With the emergence of synchrotron radiation X-ray micro-CT (Synchrotron radiation micro, CT, SR, μCT), its high luminous flux, high collimation, and high coherence characteristics can perform three-dimensional imaging of tissue micromorphological structures, and the resolution can reach submicron level. Using synchrotron radiation technology to analyze the three-dimensional microstructure of limb bones, joints and soft tissues has important research significance. There are no methods and technical parameters for live imaging of small animal limbs in the disclosed inventions.

Moreover, due to the high radiation doses of SR and μCT, which will affect the survival of small animals, it is often necessary to take the isolated tissues for imaging after the animals are killed, and it is impossible to dynamically observe the real-time healing changes in the animals. Conventional small animal immobilization devices generally use methods such as suspension or clamps to fix and brake the target area. There is no specific device for immobilizing limbs, and there is no protective device for high radiation doses. Therefore, conventional small animal immobilization devices It is not suitable for live imaging of small animals with synchrotron radiation, and there is no small animal fixation device for live imaging of synchrotron radiation among the disclosed inventions.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention proposes a live imaging system dedicated to the limbs of small animals, which can adjust the fixed position according to the size of the animal, prevent the torso from being irradiated with large doses of radiation, and ensure the survival of small animals after synchrotron radiation scanning. Synchrotron radiation X-ray micro-CT and fixation device suitable for live imaging of limbs of small animals.

The purpose of the present invention is achieved by adopting the following technical solutions:

A fixing device suitable for live imaging of small animal limbs, including a stage for placing small animals after anesthesia, a column fixed on the stage and a cover mounted on the stage, and the upper and surrounding sides of the stage A closed lead cover, the four uprights are distributed around the small animal and correspond to the positions of the limbs of the small animal, three of the uprights are fixed with ropes for fixing the limbs of the small animal, and the other upright is fixed with a vertical The sleeve is provided, the inside of the sleeve is hollow to form a cavity for the small animal to be imaged to pass through and position it, and the lead cover is provided with a through hole matching the size of the sleeve at the corresponding position of the sleeve , after the lead cover is mounted on the stage, the sleeve stretches out from the lead cover, and the positioning of the limb to be imaged by the sleeve refers to: the diameter of the cavity is larger than the diameter of the bone of the limb to be imaged in a small animal, but Slightly smaller than the outer diameter of the muscle of the limb to be imaged so that it snaps into place when the limb to be imaged passes through.

Further, the stage is provided with a plurality of through holes to form a column fixing hole for fixing the column, the inner wall of the column fixing hole is a threaded structure, and the bottom outer wall of the column is provided with an inner thread corresponding to the column fixing hole. Matching external thread.

Further, the fixing clip includes a column clamping part and a sleeve clamping part, the column clamping part is connected with the sleeve clamping part, the column clamping part includes a groove whose width matches the column diameter, and A column fixing nut is installed on one side of the groove. After the column is inserted into the groove, the column is fixed in the groove through the column fixing nut. The clamping part of the sleeve is a clamp, and the clamp passes through the The sleeve fixing nut adjusts the tightness of the clamping. The sleeve is installed in the clamp, and the sleeve is fixed in the clamp by tightening the sleeve fixing nut.

Further, the cavity of the sleeve is in the shape of a truncated cone with a small top and a large bottom, and the inner wall of the top opening of the cavity is provided with an elastic ring for clamping the calf or thigh muscles of the small animal.

A synchrotron radiation X-ray micro-CT suitable for live imaging of small animal limbs, comprising the above-mentioned fixing device, the stage of the fixing device is fixed on the rotating sample stage of the synchrotron radiation light source, and the stage is covered with The cylinder axis is set coaxially with the rotation axis of the rotary sample stage.

Further, the specific parameters of the synchrotron radiation light source are set, the energy of the light source is set to 15keV, the effective imaging resolution of the CCD detector is set to 3.25um, and the exposure time is set to 100ms.

Further, a high-resolution camera is set to capture 1080 original tomo images, 5 dark images, and 18 flat and gap images.

Further, the PITRE software used by the synchrotron radiation source is set to perform slice reconstruction of the data, and the VGstudio3.0 software is used to perform three-dimensional visualization of the reconstructed data.

Further, set the distance between the rotation axis and the CCD detector to be 10cm.

Further, the small animals are mice, rats or rabbits.

Owing to adopting above-mentioned structure, the present invention has following advantage:

1) The present invention provides a special fixation device for live imaging of small animal limbs for synchrotron radiation X-ray micro-CT imaging. At the same time, it can avoid the influence of high-dose radiation on the trunk, protect the survival of small animals to the greatest extent, and facilitate long-term animal experiments;

2) The present invention uses specific imaging parameters to realize high-precision and high-resolution imaging of limb bones, joints and soft tissues. Compared with microCT imaging, the resolution is higher, and the microstructure display is clearer, which is helpful for further analysis of limb bones, Three-dimensional microstructural characteristics of joints and soft tissues, in-depth understanding of the relationship between the structure of the motor system and biological functions.

Description of drawings

Fig. 1 is the structural representation of fixing device of the present invention;

Fig. 2 is the structural representation of lead cover of the present invention;

Fig. 3 is the structural representation of column of the present invention;

Fig. 4 is a schematic structural view of the fixing clip of the present invention;

Fig. 5 is the structural representation of synchrotron radiation X-ray micro-CT;

Figure 6 is a comparison of synchrotron radiation X-ray micro-CT and microCT scanning results.

In the figure: 1. stage; 2. column; 3. sleeve; 4. fixing clip; 5. lead cover; 6. column fixing hole; 7. fixed part; 8. threaded part; 9. through hole; 10 1. Column fixing nut; 11. Column clamping part; 12. Sleeve fixing nut; 13. Sleeve clamping part; 14. Light source; 15. Monochromatic light mirror; 16. Rotating sample stage; 17. CCD detector.

Detailed ways

A specific implementation of a synchrotron radiation light source and a fixing device suitable for live imaging of limbs of small animals will be described in detail below with reference to the accompanying drawings and specific examples.

As shown in Figures 1 to 6, a synchrotron radiation X-ray micro-CT suitable for live imaging of small animal limbs includes an object stage 1 fixed on a rotating sample stage 16 of a synchrotron radiation X-ray micro-CT. The object table 1 is used to place an anesthetized small animal. In the present embodiment, the small animal refers to a rodent, preferably a mouse, a rat or a rabbit. The object table 1 is a rectangular plate structure, and the object table 1 There are a plurality of column fixing holes 6 arranged in an array, the column fixing holes 6 are through holes, and the inner wall thereof is a threaded structure, and the column fixing holes 6 of the stage 1 are internally threaded with four columns 2, small animals After being placed on the stage 1, four uprights 2 are installed around the small animal, three of which are connected with the three legs of the small animal through ropes, thereby preventing the limbs of the small animal from moving during the imaging process, and the other one is fixed on the upright There is a fixing clip 4, the fixing clip 4 is used to fix the sleeve 3, keep the sleeve 3 stable and placed vertically, the fourth leg used for synchrotron radiation scanning passes through the sleeve 3 from bottom to top, Make the ankle joint of the fourth leg pass through the top opening of the sleeve 3, so that the fourth leg is fixed through the sleeve 3. After the small animal is properly fixed, cover the lead cover 5, and the fourth leg is covered by the lead cover 5. Protrude from the through hole 9 of the lead cover 5, and the protruding part is the target area for synchrotron radiation scanning.

Fig. 2, Fig. 3, Fig. 4, show the detailed view of stage, column, sleeve, fixing clamp and lead cover, the effect of described column fixing hole 6 is to fix column 2 on the one hand, can be in on the other hand After the lead cover 5 is covered, the circulation of the internal and external air is realized through the column fixing hole 6 to ensure the survival of the animal to be imaged. The column 2 is a cylindrical structure, composed of a fixed part 7 and a threaded part 8 at the bottom. The fixing part 7 is used for fixing the rope to connect with the limbs of the small animal, and the fixing clip 4 can be installed at the same time. Body size adjustment corresponding fixed position. The fixed clip 4 includes a column clamping part 11 and a sleeve clamping part 13, the column clamping part 11 is connected with the sleeve clamping part 13, the column clamping part 11 is a groove, and one side of the groove is installed There is a column fixing nut 10. After the column is inserted in the groove, the column fixing nut 10 fixes the column in the groove. The sleeve clamping part 13 is a clamp, and the clamp passes through the sleeve fixing nut 12 To adjust the tightness, the sleeve 3 is installed in the clamp, and the sleeve 3 is fixed in the clamp by tightening the sleeve fixing nut 12. By adjusting the height of the clamp on the column 2, on the one hand, the first scanning point is fixed. The four legs prevent it from shaking. On the other hand, by adjusting the position of the sleeve 3, guide the feet of the small animal to pass through the sleeve 3, so as to ensure that the ankle joint is exposed from the top of the sleeve 3, which is convenient for the subsequent fourth leg to pass through the lead. The through hole 9 is exposed on the cover 5 .

The sleeve 3 has a hollow circular platform structure, and is divided into models with different heights and inner diameters according to the size of the small animal. The inner wall of the opening at the top of the inner chamber of the sleeve is provided with a hole for the legs of the small animal to pass through and to facilitate the clamping of the small animal's calf. Elastic ring, the elastic ring is made of elastic material, the opening of the elastic ring is slightly smaller than the diameter of the calf of the small animal, when the leg of the small animal is stuck in the sleeve 3, the elastic ring at the top of the sleeve 3 will hold the calf of the small animal The part is fixed, so that the ankle joint of the small animal protrudes from the sleeve 3, and the elastic ring prevents the calf from moving during the imaging process, thereby ensuring that the ankle joint of the small animal is fixed. In this way, the ankle joint of the small animal is fixed by the sleeve 3. The cartridge 3 is fixed by the sleeve holding portion 13 of the fixing clip 4 .

The lead cover 5 is a cover-shaped structure made of lead material, which can prevent radiation from penetrating. The lead cover 5 has a through hole 9 on its surface. When the lead cover 5 is used to cover the torso of the small animal, the lower limb to be scanned can protrude from the through hole 9 for scanning.

When performing synchrotron radiation imaging, as shown in Figure 5, the synchrotron radiation light source includes a light source 14, a monochromator 15, a rotating sample stage 16 and a CCD detector 17, and the light source 14 is used to provide parallel light with energy at 8.0, 72.5 keV , the monochromator 15 is used to convert light into a highly coherent monochromatic beam, the rotating sample stage 16 is fixed downstream of the light source 14, and the CCD detector 17 is located on an adjustable guide rail. After the mouse was anesthetized, it was properly fixed on the stage 1 to ensure that the scanning position was at the rotation center of the rotating sample stage 16. In order to ensure the highest imaging quality and the relatively lowest radiation dose, the following scanning parameters were used: the energy of the light source 14 was set to 15keV, the effective imaging resolution of the CCD detector 17 is set to 3.25um, the distance between the sample and the detector is set to 10cm (both phase contrast and absorption contrast), and the exposure time is set to 100ms (to reduce the scanning time). The resolution camera captures 1080 original tomo images, 5 dark images, and 18 flat and gap images. The PITRE software was used for slice reconstruction of the data, and the VG studio3.0 software was used for three-dimensional visualization of the reconstructed data.

Figure 6 is a comparison of microCT and SRμCT imaging of mouse ankle joints, in which A in Figure 6 is a comparison of cross-section and distorted surface; B in Figure 6 is the gray value distribution map of the lined area; C in Figure 6 is SRμCT Structural diagram of the ankle joint. It can be seen that compared with microCT imaging, SRμCT shows more clearly the details of the ankle joint.

The above are preferred embodiments of the present invention, but those skilled in the art should understand that various changes are made to the present invention in form and details without departing from the spirit and scope of the present invention defined by the appended claims. , all belong to the protection scope of the present invention.

Claims (8)

1. A fixing device suitable for live imaging of toy limbs, characterized in that: the device comprises an object table (1) for placing a small animal after anesthesia, upright posts fixed on the object table (1) and a lead cover (5) for covering the upper part and the periphery of the object table (1), wherein four upright posts are distributed on the periphery of the small animal and correspond to the positions of the limbs of the small animal, three upright posts are fixedly provided with ropes for fixing the limbs of the small animal, the other upright post is fixedly provided with a vertically arranged sleeve through a fixing clamp (4), a cavity for the small animal to pass through and locate the limbs to be imaged is formed in the sleeve, the inner wall of an opening at the top of the cavity is provided with an elastic ring for clamping the muscles of the small animal's lower leg or thigh, the lead cover (5) is provided with a through hole matched with the sleeve in size at the position corresponding to the sleeve, and the lead cover (5) is covered on the object table (1) and then extends out of the lead cover (5);

the object stage (1) is provided with a plurality of through holes to form an upright post fixing hole (6) for fixing an upright post, the inner wall of the upright post fixing hole (6) is of a threaded structure, and the outer wall of the bottom of the upright post is provided with external threads matched with the internal threads of the upright post fixing hole (6);

the fixing clamp is characterized in that the fixing clamp (4) comprises a column clamping part (11) and a sleeve clamping part (13), the column clamping part (11) is connected with the sleeve clamping part (13), the column clamping part (11) comprises a groove with the width matched with the diameter of the column, a column fixing nut (10) is arranged on one side of the groove, the column is fixed in the groove through the column fixing nut (10) after being inserted into the groove, the sleeve clamping part (13) is a clamp, the clamp adjusts clamping tightness through the sleeve fixing nut (12), the sleeve is arranged in the clamp, and the sleeve is fixed in the clamp through screwing the sleeve fixing nut (12).

2. The fixation device for in vivo imaging of small animal extremities as claimed in claim 1, wherein: the cavity of the sleeve forms a round table with small top and large bottom.

3. Synchrotron radiation X-ray micro-CT suitable for the living imaging of small animal limbs, comprising a fixing device according to claim 1 or 2, characterized in that: the object stage (1) of the fixing device is fixed on a synchronous radiation X-ray micro CT rotary sample stage (16), and the axis of a sleeve on the object stage (1) is coaxial with the rotary axis of the rotary sample stage (16).

4. Synchrotron radiation X-ray micro-CT suitable for the living imaging of small animal limbs according to claim 3, characterized in that: specific parameters of the synchrotron radiation X-ray micro CT are set, the energy of the light source (14) is set to 15keV, the effective imaging resolution of the CCD detector (17) is set to 3.25um, and the exposure time is set to 100ms.

5. Synchrotron radiation X-ray micro-CT suitable for in vivo imaging of small animal limbs according to claim 4, characterized in that: setting a high-resolution camera to capture 1080 original tomo images, 5 dark images and 18 flat and gap images.

6. Synchrotron radiation X-ray micro-CT suitable for in vivo imaging of small animal limbs according to claim 4, characterized in that: and setting PITRE software adopted by synchrotron radiation X-ray micro CT to reconstruct the data in a slicing way, and adopting VG studio3.0 software to perform three-dimensional visualization on the reconstructed data.

7. Synchrotron radiation X-ray micro-CT suitable for in vivo imaging of small animal limbs according to claim 4, characterized in that: the distance between the rotation axis and the CCD detector (17) is set to be 10cm.

8. Synchrotron radiation X-ray micro-CT suitable for in vivo imaging of small animal limbs according to claim 5, characterized in that: the small animal is a mouse, a rat or a rabbit.

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