CN106901764A - A kind of PET/CT image quality detection body mould of apery head and preparation method thereof - Google Patents

Abstract

A kind of PET/CT image quality the invention discloses apery head detects body mould and preparation method thereof, including：The PET/CT image quality detection mould of the apery head has the body mould body of human body head configuration, and the body mould body is internally provided with least one dismountable replacement module；Dismountable replacement module is selected from one or more in brain tumor analog module, the image co-registration degree test module of PET/CT, the correction for attenuation test module of PET/CT, PET performance parameter tests module or CT performance parameter test modules.Body mould of the invention is the quality testing body mould with morphological feature, it is capable of human body head profile, structure and the focus of simulating realistic, can be used for carrying out quality control to human body head PET/CT imagers, can be also used for find PET/CT imagers optimal sweep parameter, for demonstration lesson, for tracer screening etc. aspect, be with a wide range of applications.

Description

A PET/CT imaging quality detection phantom imitating human head and its preparation method

technical field

The invention relates to the field of PET/CT quality assurance and quality control, in particular to a human head-like PET/CT imaging quality detection phantom and a preparation method thereof.

Background technique

In recent years, with the rapid development of medical imaging technology, multimodal joint imaging technology has received extensive attention, such as PET/CT (Positron Emission Tomography/Computed Tomography, Positron Emission Tomography/X-ray Computed Tomography) Among them, PET can obtain functional and metabolic information very well, which belongs to functional imaging and has high sensitivity to diseased tissues, but its spatial resolution is low, and PET information cannot be accurately positioned; CT can provide high High-resolution images, but because they belong to anatomical imaging, they cannot reflect the functional changes of tissues well. The combination of PET and CT (PET/CT multimodal two-in-one imaging system) can make up for the shortcomings of PET imaging and CT imaging alone, and realize the complementarity of functional images and anatomical image information, thereby providing more and more accurate information.

At present, the phantoms used for quality control of PET/CT imagers have problems such as single types and simple structures. The performance parameters of the CT part cannot perform quality control on the imaging quality of the combined use of PET/CT. Therefore, there is an urgent need for a matching phantom suitable for PET/CT imagers.

Contents of the invention

Aiming at the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a PET/CT imaging quality detection phantom imitating a human head. The phantom of the present invention is a three-dimensional structural quality detection phantom with morphological characteristics, which can simulate the real shape, structure and focus of the human brain, and can be used for quality control of the PET/CT imager of the human head. It can be used to find the optimal scanning parameters of PET/CT imager, to teach and demonstrate, to screen tracers, etc., and has a wide range of applications.

To achieve the above object, the present invention adopts the following technical solutions:

The first aspect of the present invention provides a PET/CT imaging quality detection phantom imitating a human head, comprising: a phantom body having the shape of a human head, at least one detachable replacement module;

The detachable replacement module is selected from one of the brain tumor simulation module, PET/CT image fusion test module, PET/CT attenuation correction test module, PET performance parameter test module or CT performance parameter test module or Various.

Preferably, the detachable replacement module is located inside the phantom body above the brain.

Preferably, the brain tumor simulation module is a hollow sphere structure; the hollow sphere structure is perfused with a tracer.

More preferably, the tracer is 18F-FDG (fluorodeoxyglucose, fluorodeoxyglucose) solution.

Preferably, the PET/CT image fusion test module includes: at least one of a line source and a hollow sphere or a cube; the line source, hollow sphere or cube can be used for the image fusion test independently.

The line source is an aluminum tubular structure, and a tracer, such as FDG solution, can be perfused inside;

The hollow sphere or cube is filled with a tracer, such as FDG solution.

More preferably, a plurality of hollow spheres with different diameters form a circumference, and the centers of the hollow spheres are on the same circumferential layer; or the hollow spheres are arranged in a row according to their diameters.

If the image fusion test module of PET/CT includes a line source and a hollow sphere, there is no special restriction on the relative positions of the line source and the hollow sphere, for example, the line source can be set outside the circle formed by multiple hollow spheres .

During the test, the FGD solution was injected into the line source and the hollow sphere for PET/CT scanning, and the image fusion accuracy was obtained based on the obtained scanning images.

The PET/CT image fusion test module can also be used to test the low contrast resolution of PET.

The low-contrast resolution test method of PET is: use multiple hollow spheres with different diameters to test the low-contrast resolution of PET. During the test, inject tracers into multiple hollow spheres and perform PET scanning. According to the obtained scanning images Determines low contrast resolution.

Preferably, the attenuation correction test module of PET/CT includes: at least one hollow cylindrical insert, the hollow cylindrical insert is divided into two parts, one part is located in the phantom body, and the other part is located in the phantom body outside.

Both the part of the hollow cylindrical insert inside the phantom body and the part outside the phantom body are filled with a tracer, such as FDG solution.

The part of the hollow cylindrical insert inside the phantom body and the part outside the phantom body are connected by threads.

During the test, the tracer is injected into the part of the hollow cylindrical insert located inside the phantom body and the part outside the phantom body, and a PET/CT scan is performed. According to the scanned image of the part of the hollow cylindrical insert located inside the phantom body The accuracy of the attenuation correction is determined by counting images of the portion of the hollow cylindrical insert located within the phantom body.

Preferably, the PET performance parameter testing module is composed of several groups of cylinders with different diameters.

The cylinder is a hollow or solid structure.

When the cylinder is a hollow structure, it is used to test the system resolution under the high contrast structure, and the tracer (such as FGD solution) is filled in the cylinder during the test.

When the cylinder is a solid structure, it is used to test the system resolution under low contrast structure, and the tracer is filled in the area outside the cylinder during the test.

During the test, the PET scan is performed after the tracer is filled, and the resolution is determined according to the smallest size (diameter) that can be resolved in the scanned image.

Preferably, the CT performance parameter testing module includes: a CT spatial resolution testing module, a CT density resolution testing module and a radiation dose testing module;

The CT spatial resolution test module is composed of several groups of round holes with different diameters, and the distance between each row of round holes is the same as the diameter of the row of round holes.

The distance between the rows may be a fixed distance; it may not be specifically limited.

The CT density resolution testing module is composed of several groups of circular holes with different diameters distributed radially; the diameters of the circular holes in each group are the same, and the circular holes are filled with materials of different contrasts.

The radiation dose testing module includes: an ionization chamber probe and a chamber for placing the ionization chamber probe; the ionization chamber probe is connected with an external radiation meter for measuring radiation dose during CT scanning.

Preferably, the cross section of the chamber where the ionization chamber probe is placed is circular or rectangular.

In view of the deficiencies in the prior art above, the object of the present invention is to provide a method for preparing a human head-like PET/CT imaging quality inspection phantom. The phantom of the present invention is a three-dimensional structural quality detection phantom with morphological characteristics, which can simulate the real shape, structure and focus of the human brain, and can be used for quality control of the PET/CT imager of the human head. It can be used to find the optimal scanning parameters of PET/CT imager, to teach and demonstrate, to screen tracers, etc., and has a wide range of applications.

To achieve the above object, the present invention adopts the following technical solutions:

The second aspect of the present invention provides a method for preparing the above-mentioned human-like head PET/CT imaging quality detection phantom, the steps are as follows:

(1) Construct a phantom body with the shape of the human head according to the CT scan data of the human head;

(2) At least one detachable replacement module is arranged inside the constructed phantom body.

In step (1), the bone structure of the phantom body is three-dimensionally printed using bone tissue equivalent materials, and the skin and other internal tissues of the phantom body are three-dimensionally printed using soft tissue equivalent materials.

Alternatively, the skeletal structure of the phantom body is three-dimensionally printed using bone tissue equivalent materials, the skin of the phantom body, that is, the scalp part, is three-dimensionally printed using ordinary materials, and other tissues inside the phantom body are made of prepared soft tissue equivalent materials Perform priming.

The bone tissue equivalent material, the soft tissue equivalent material, and the common material are all existing materials, and the prepared soft tissue equivalent material is existing or prepared agarose gel:

For example, the bone tissue equivalent material is a high-density resin with a Shore hardness greater than 90 in existing 3D printing materials.

The soft tissue equivalent material is EVA resin with lower density in existing 3D printing materials.

The common material is a common plastic material in existing 3D printing materials.

The prepared soft tissue equivalent material is prepared agarose gel.

For above-mentioned deficiencies in the prior art, the object of the present invention is to provide the PET/CT imaging quality detection phantom of above-mentioned human head in the quality control of PET/CT imager, find the optimal scanning parameter of PET/CT imager, Use in teaching demonstrations and/or screening of tracers. The phantom of the present invention is a three-dimensional structural quality detection phantom with morphological characteristics, which can simulate the real shape, structure and focus of the human brain, and can be used for quality control of the PET/CT imager of the human head. It can be used to find the optimal scanning parameters of PET/CT imager, to teach and demonstrate, to screen tracers, etc., and has a wide range of applications.

To achieve the above object, the present invention adopts the following technical solutions:

The third aspect of the present invention provides the quality control of the PET/CT imaging quality detection phantom of the human head in the PET/CT imager, searching for the optimal scanning parameters of the PET/CT imager, teaching demonstration and/or demonstration. use in the screening of tracers.

Beneficial effects of the present invention:

(1) The PET/CT imaging quality detection phantom imitating the human head of the present invention has a three-dimensional structure, which can simulate the shape and structure of the human head in terms of external shape and internal structure. In addition, the PET/CT imaging quality detection phantom of the human head of the present invention has one or more detachable replacement modules, wherein one replacement module is a preset lesion structure for simulating tumors in the human head; Other replacement modules can be used to test the parameters of the PET/CT instrument, so as to evaluate the performance of the PET/CT instrument according to the measured parameters.

(2) The PET/CT imaging quality detection phantom of the imitation human head of the present invention can simulate real human head craniocerebral shape, structure and lesion, can be used for carrying out quality control to human head PET/CT imager, also can It can be used to find the optimal scanning parameters of the PET/CT imager, be used for teaching demonstration, and be used for tracer screening, etc., and has a wide range of applications.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute improper limitations to the present application.

Fig. 1 is the structural representation of phantom body of the present invention;

Fig. 2 is the structural representation of the tumor simulation module in the PET/CT imaging quality detection phantom of humanoid head of the present invention (side view sectional view);

Fig. 3 is the line source structure schematic diagram (front view) of the image fusion degree test module in the PET/CT imaging quality detection phantom of human head of the present invention;

Fig. 4A is a top view of the hollow sphere of the image fusion test module in the PET/CT imaging quality test phantom of the human head of the present invention.

Fig. 4B is a front view of the hollow sphere of the image fusion test module in the PET/CT imaging quality test phantom of the human head of the present invention.

Fig. 5 is the structural representation of the attenuation correction test module of PET/CT in the PET/CT imaging quality detection phantom of human head of the present invention;

6A is a cross-sectional view of a PET high-contrast resolution module;

6B is a cross-sectional view of a PET low-contrast resolution module;

Figure 7A: Schematic diagram of the structure of the CT spatial resolution test module;

Figure 7B: Schematic diagram of the structure of the CT density resolution test module;

Figure 8: Schematic diagram of the radiation dose test module;

Among them, 1-skin, 2-skeleton, 3-removable replacement module, 4-brain tissue, 5-hollow sphere, 6-first line source, 7-second line source, 8-hollow cylindrical plug-in, 9-hollow The part of the cylindrical insert located inside the phantom body, 10 - the part of the hollow cylindrical insert located outside the phantom body, 11 - the ionization chamber probe, and 12 - the radiation meter.

detailed description

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

As introduced in the background technology, the phantoms used for quality control of PET/CT imagers in the prior art have problems such as single types and simple structures, and cannot perform quality control on the imaging quality of PET/CT combined use. Based on this, the present invention proposes a human head-like PET/CT imaging quality detection phantom and a preparation method thereof.

In one embodiment of the present application, a PET/CT imaging quality detection phantom imitating the human head is provided, as shown in Figure 1, the shape of the phantom body simulates the shape of the real human head and brain , At least one detachable replacement module 3 is provided at the position above the brain inside the phantom body; the detachable replacement module 3 can be a cuboid or a cylinder, and its shape is not limited here. The phantom body comprises skin 1 , bone 2 , detachable replacement module 3 and brain tissue 4 .

For example, after the overall production of the phantom body is completed, a cuboid A is picked at the brain above the phantom body, and after the cuboid A is removed, a corresponding detachable replacement module 3 can be selected and installed on the phantom according to the test requirements. superior. When there is no need to install a replacement module, the cuboid A can be put back on the phantom body. At this time, the phantom is in the form of a complete human head and brain.

The detachable replacement module 3 is selected from one of the brain tumor simulation module, PET/CT image fusion test module, PET/CT attenuation correction test module, PET performance parameter test module or CT performance parameter test module or more.

For example, the replacement module B1 is used to simulate the brain tumor simulation module;

The replacement module C1 is the image fusion test module of PET/CT, and the replacement module C2 is the attenuation correction test module of PET/CT;

The replacement module D1 is a PET performance parameter test module, and the replacement module D2 is another PET performance parameter test module, etc.;

The replacement module E1 is a CT performance parameter testing module, and the replacement module E2 is another CT performance parameter testing module.

As a preferred solution, a sphere structure is used to simulate the shape of the tumor in the human head, as shown in Figure 2, after the sphere structure is perfused with a tracer, such as 18F-FDG (fluorodeoxyglucose, fluorodeoxyglucose) solution, it can be carried out under PET. imaging.

As a preferred solution, the PET/CT image fusion test module includes: at least one of a line source and a hollow sphere 5 or a cube; the line source, the hollow sphere 5 or a cube can be used for image fusion testing alone.

The line source is an aluminum tubular structure, as shown in FIG. 3 , including a first line source 6 and a second line source 7 , and tracers such as FDG solution can be perfused inside the first line source 6 and the second line source 7 .

The hollow sphere 5 or cube is filled with a tracer, such as FDG solution.

Preferably, a plurality of hollow spheres 5 with different diameters form a circle, and the centers of the hollow spheres 5 are on the same circumferential layer, as shown in Figure 4A; or the hollow spheres 5 are arranged in a row according to the diameter, as Figure 4B.

If the image fusion test module of PET/CT includes the line source and the hollow sphere 5, then there is no special restriction on the relative position of the line source and the hollow sphere 5, for example, the line source can be arranged on a plurality of hollow spheres 5. outside of the circle.

During the test, the FGD solution is injected into the line source and the hollow sphere 5 for PET/CT scanning, and the accuracy of image fusion is obtained according to the obtained scanning images.

The above PET/CT image fusion test module can also be used to test the low contrast resolution of PET.

The test method is: use multiple hollow spheres 5 with different diameters to test the low-contrast resolution of PET. During the test, inject FDG solution into the multiple hollow spheres 5, perform PET scanning, and determine the low-contrast resolution according to the obtained scanned images.

As a preferred solution, the attenuation correction test module of PET/CT includes: at least one hollow cylindrical insert 8, the hollow cylindrical insert 8 is divided into two parts, one part is located in the phantom body, and the other part is located in the phantom body. Outside the body of the phantom, as shown in Figure 5.

Both the part 9 of the hollow cylindrical insert inside the phantom body and the part 10 of the hollow cylindrical insert outside the phantom body are filled with a tracer, such as FDG solution.

Since the FDG solution needs to be contained in the hollow cylindrical insert, its material is required not to react with the FDG solution.

Preferably, the part 9 of the hollow cylindrical insert located inside the phantom body and the part 10 of the hollow cylindrical insert located outside the phantom body are connected by threads.

During the test, FDG solution is injected into the part 9 where the hollow cylindrical insert is located inside the phantom body and the part 10 where the hollow cylindrical insert is located outside the phantom body, and PET/CT scanning is performed, and the hollow cylindrical insert obtained according to the scan is located in the phantom body The accuracy of the attenuation correction was determined by counting the portion 9 images and the portion 10 images of the hollow cylindrical insert located outside the phantom body.

As a preferred solution, the PET performance parameter testing module includes: a PET high-contrast resolution module and a PET low-contrast resolution module;

Among them, the PET high-contrast resolution module is used to test the system resolution under the high-contrast structure. Specifically, there are 6 regions of circular holes in the disc-shaped plexiglass, and the diameters of the circular holes in different regions are different. A cross-sectional view of the circular hole structure is shown in Figure 6A.

When testing, fill the tracer in the round hole.

The PET low-contrast resolution module is used to test the system resolution under the low-contrast structure. Specifically, the module consists of 6 groups of solid cylinders with different diameters. The cross-sectional view is shown in Figure 6B.

During testing, the area outside the cylinder is filled with tracer.

As a preferred solution, the CT performance parameter testing module includes: a CT spatial resolution testing module (ie high contrast resolution), a CT density resolution testing module (ie low contrast resolution) and a radiation dose testing module.

Among them, the high-contrast resolution of CT refers to the ability to distinguish the smallest target when the contrast between the target and the background in the image is greater than 10%, usually represented by the size of the smallest periodic structure target (such as a hole or line pair) that can be resolved .

In one embodiment of the present invention, the high-contrast resolution is tested with hole-like structures of different diameters, specifically, circular holes of different diameters are arranged in a disc-shaped plexiglass, and the distance between each row of circular holes is the same as The circular holes have the same diameter, and the smallest circular hole that can be distinguished subjectively in the image is the spatial resolution of CT. The distribution of the circular holes is shown in Figure 7A.

The low-contrast resolution of CT is the ability to distinguish the smallest target when the contrast between the target and the background in the image is less than 1%. It is usually expressed by the size of the smallest object that can be distinguished and the corresponding contrast.

Specifically, the module consists of ten groups of circular holes with different diameters, which are distributed radially, as shown in Figure 7B. The three circular holes in each group have the same diameter, and the three circular holes contain materials with different contrasts, for example , and the contrast ratios are 0.3%, 0.5%, and 1.0%, respectively.

It should be noted that, in the structures shown in Fig. 6A, Fig. 6B, Fig. 7A and Fig. 7B, the number of round holes/cylindrical regions and the number of round holes/cylindrical regions in each region shown in the figure below are only used as To exemplify and illustrate, rather than limit the present invention. The specific number can be increased or decreased according to actual needs.

The radiation dose test module, as shown in Figure 8, includes: an ionization chamber probe 11 and a chamber where the ionization chamber probe 11 is placed; the ionization chamber probe 11 is connected with an external radiation meter 12 for measuring CT scanning radiation dose.

Preferably, the cross section of the chamber where the ionization chamber probe 11 is placed is circular or rectangular.

In order to enable those skilled in the art to understand the technical solution of the present application more clearly, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

The test materials used in the examples of the present invention are all conventional test materials in the field, and can be purchased through commercial channels.

Example 1:

1. The structure and material of the phantom body:

The overall shape of the phantom is the shape of a simulated human head. Specifically, a simulated human head model is constructed based on CT scan data of a real human head, and a simulated human head model is produced by 3D printing technology based on the constructed model.

(1) Selection of model materials:

All bone 2 structures of the human head are 3D printed using bone tissue equivalent materials; the skin 1 of the human head and other internal tissues (brain tissue 4) of the human head are all 3D printed using soft tissue equivalent materials.

Among them, the bone tissue equivalent material is a high-density resin with a Shore hardness greater than 90 in existing 3D printing materials.

The soft tissue equivalent material is EVA resin with lower density in existing 3D printing materials.

(2) The structure of the phantom:

The phantom includes: a phantom body, on which there is a detachable replacement module 3 (for example, as shown in FIG. 1 , located at the upper brain of the human head model). When the detachable replacement module 3 is installed on the phantom body, the phantom is in the shape of a complete human head. Wherein, the detachable replacement module 3 may be a cuboid or a cylinder, and its shape is not limited here.

After the detachable replacement module is removed, other replacement modules can be installed on the phantom body to test corresponding parameters through the replacement module.

Other replacement modules can be: brain tumor simulation module, PET/CT image fusion test module, PET/CT attenuation correction test module, PET performance parameter test module, CT performance parameter test module.

Example 2:

1. The structure and material of the phantom body:

The overall shape of the phantom is the shape of a human head. Specifically, a human head model is constructed according to CT scan data of a real human head, and a human head model is produced by 3D printing technology according to the constructed model.

(1) Selection of model materials:

All bones 2 structures of the human head are printed with bone equivalent materials, the skin 1 of the human head is made with ordinary materials, and other tissues (brain tissue 4) inside the human head are printed with prepared soft tissue equivalent materials. Infusion molding.

The bone equivalent material is a high-density resin with a Shore hardness greater than 90 in existing 3D printing materials.

Ordinary materials are common plastic materials in existing 3D printing materials.

The prepared soft tissue equivalent material is prepared agarose gel.

(2) The structure of the phantom:

The phantom comprises: a phantom body, two detachable replacement modules 3 are arranged in the phantom body (for example, as shown in Figure 1, be positioned at the top brain position of human head model), wherein, a replacement module is Internal tumor simulation module, preset lesion structure, used to simulate tumors in the human head; other replacement modules can be selected from PET/CT image fusion test module, PET/CT attenuation correction test module, PET performance parameter test The module or CT performance parameter test module is used to test the parameters of the PET/CT instrument, so as to evaluate the performance of the PET/CT instrument according to the measured parameters.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

1. a kind of PET/CT image quality of apery head detects body mould, it is characterised in that including：With human body head profile Body mould body, the body mould body is internally provided with least one dismountable replacement module；

Dismountable replacement module is selected from brain tumor analog module, the image co-registration degree test module of PET/CT, PET/ One or more in the correction for attenuation test module of CT, PET performance parameter tests module or CT performance parameter test modules.

2. the PET/CT image quality of apery head according to claim 1 detects body mould, it is characterised in that described removable The replacement module for unloading is located at the brain localization of the top inside body mould body.

3. the PET/CT image quality of apery head according to claim 1 and 2 detects body mould, it is characterised in that described Brain tumor analog module is hollow ball structure；Tracer is perfused with the hollow ball structure.

4. the PET/CT image quality of apery head according to claim 1 and 2 detects body mould, it is characterised in that described The image co-registration degree test module of PET/CT includes：At least one in line source and hollow ball or square；

The line source is aluminum tubular structure, and inside can irrigate tracer；

Tracer is filled with the hollow ball or square.

5. the PET/CT image quality of apery head according to claim 1 and 2 detects body mould, it is characterised in that described The correction for attenuation test module of PET/CT, including：At least one hollow cylinder plug-in unit, the hollow cylinder plug-in unit is divided into two Point, a part is located to be had in human body head outline body mould body, and it is external that another part is located at body calligraphy or painting model.

6. the PET/CT image quality of apery head according to claim 1 and 2 detects body mould, it is characterised in that described PET performance parameter test modules, are made up of the cylinder of some groups of different-diameters；

The cylinder is hollow or solid construction.

7. the PET/CT image quality of apery head according to claim 1 and 2 detects body mould, it is characterised in that described CT performance parameter test modules, including：CT spatial resolutions test module, CT density resolutions test module and radiation agent are measured Die trial block；

The CT spatial resolutions test module is made up of the circular hole of some groups of different-diameters, each to arrange the distance between circular hole and institute It is identical in the diameter of row's circular hole；

The CT density resolutions test module is made up of the circular hole of some groups of different-diameters for radially distributing；Each group The diameter of circular hole is identical, and the material filled with different contrast in circular hole.

8. the PET/CT image quality of apery head according to claim 7 detects body mould, it is characterised in that the radiation Dosage test module, including：The chamber that ionisation chamber is popped one's head in and placement ionisation chamber is popped one's head in；The ionisation chamber probe and outside radiation Gauge is connected, for measuring dose of radiation during CT scan.

9. the PET/CT image quality of the apery head described in any one of claim 1-8 detects the preparation method of body mould, and it is special Levy and be, step is as follows：

(1) CT scan data according to human body head builds the body mould body with human body head profile；

(2) at least one dismountable replacement module is set in the inside of the body mould body for building.

10. the PET/CT image quality of the apery head described in any one of claim 1-8 detects body mould in PET/CT imagers Quality control, the purposes found in the optimal sweep parameter of PET/CT imagers, demonstration lesson and/or the screening of tracer.