CN212466008U - PET/CT performance detection die body - Google Patents

Abstract

The utility model relates to a PET/CT performance detection die body, PET/CT performance detection die body comprise PET image quality detection module and CT performance detection module, and two modules connect into whole, once can detect PET performance and CT performance, and the clean shot has increased 24 mm clean shots and 7mm clean shots except including 6 hollow balls that distribute according to the standard specification, can detect the PET image quality of small focus, can the qualitative aassessment spatial resolution. The card of lower extreme on the plug-in components of lung is in PET image quality detection module top cap recess and PET image quality detection module bottom recess, avoids the plug-in components of lung to float because of density is less than water and leads to the die body installation difficulty in the die body, makes the solution of dispensing easy and the time short, reduces radiopharmaceutical activity loss, alleviates the ionizing radiation to the experimenter. The image evaluation method can automatically analyze and process the image quality of the die Body image data acquired by PET/CT equipment of different brands and models, and is also suitable for the NEMA IEC Body die Body. Can be analyzed off-line, and does not occupy the time of a PET/CT device.

Description

PET/CT performance detection die body

Technical Field

The utility model relates to a medical field's test instrument especially relates to a PET/CT performance detection die body.

Background

With the wide application of PET/CT, the performance requirements of people on PET/CT are gradually improved, and the research on PET/CT performance detection technology is widely concerned.

The quality of the PET image is presented as a terminal for the quality of the PET/CT performance, and is an important performance parameter of the PET/CT. The CT device is mainly used for describing anatomical characteristics such as size, position, morphology and the like of lesions; however, many diseased tissues have CT values that differ only slightly from normal tissues, and therefore, low contrast resolution of CT is also important for PET/CT devices. The generation of the PET/CT fusion image is obtained by registering and fusing two images independently generated by the PET device and the CT device through software, but the precision of image fusion is still influenced by factors such as the displacement of a scanning bed, the displacement of human organs and the like, so that the detection of the PET/CT registration precision is very important.

At present, the performance parameters of the PET/CT apparatus are usually detected internationally according to the performance detection methods specified in the NEMA NU 2 series of standards and the IEC 616751 series of standards. The two standards are revised and mutually quoted for several times, the detection methods of multiple parameters in the current version are the same, wherein the detection methods of the image quality are completely the same, the PET image quality is detected by measuring the contrast and the background change rate, and the accuracy of scattering correction and attenuation correction is detected by measuring the residual error of the lung; the PET/CT registration accuracy is detected by measuring the spherical center deviation of a sphere in three directions of x, y and z in a PET image and a CT image.

According to the detection method of image quality in the current standard, a NEMA IEC Body phantom produced by American DSC company is generally used at home and abroad to detect the PET image quality, the scattering correction and attenuation correction accuracy and the PET/CT registration accuracy in the PET/CT equipment. The phantom simulates a heat range by means of 4 hollow spheres of different sizes filled with the radioactive contrast agent fluorodeoxyglucose solution (FDG solution), called thermal spheres; simulating a cold focus by 2 hollow balls with different sizes and filled with pure water, wherein the hollow balls are called cold balls; the hot ball and the cold ball can be used for measuring contrast and background change rate, and the higher the contrast and the lower the background change rate, the better the PET/CT equipment PET image quality is. Simulating the lungs by means of a hollow tube filled with a low density foam inside, called a pulmonary insert; the pulmonary inserter can be used for measuring lung error residual, and the lower the lung error residual is, the higher the scattering correction and attenuation correction accuracy of the PET/CT device is. The thermal sphere of the phantom may also be used to measure the center of sphere deviation, with lower center of sphere deviation indicating higher PET/CT registration accuracy. With the rapid development of the PET/CT technology, the image quality detection method specified in the existing phantom and standard cannot completely cover the performance detection requirement of the current PET/CT device with time, and the following 4 problems mainly exist:

1. in recent years, the PET/CT technology level is increasing, and more applied to early clinical diagnosis of diseases such as nervous system, tumor and cardiovascular system, etc., and tiny lesions are discovered so as to avoid missing the best period of disease treatment. However, the minimum size of a sphere used for detecting image quality parameters in the NEMA IEC Body phantom is 10mm, and the requirement for image quality detection of a tiny focus cannot be met.

2. The existing detection die body and the method can not meet the detection requirement of CT low contrast resolution of PET/CT equipment:

the NEMA IEC Body motif cannot detect CT low contrast resolution, and the Catphan motif is required to detect the parameter.

The Catphan phantom has a large volume, and if the Catphan phantom is scanned with the NEMA IEC Body phantom at the same time, the PET image is scattered, so the NEMA IEC Body phantom and the Catphan phantom cannot be scanned at the same time, that is, the detection of three parameters of the quality of the PET image, the accuracy detection of scattering correction and attenuation correction, and the PET/CT registration accuracy cannot be synchronously performed with the detection of the CT low contrast resolution at one time; if scanning is performed twice, the detection time and experimental error are increased due to factors such as die body placement position difference and repeatability error.

Moreover, the Catphan motif is a special detection motif of the CT equipment, comprises a plurality of detection modules with high contrast resolution, low contrast resolution, image uniformity, layer thickness, thread pitch, CT value and the like, and has higher cost; however, the resolution of the PET image is low, the resolution of the CT image is high, and in order to meet the fusion condition of the PET/CT image, the performance of the CT part of the PET/CT equipment is generally lower than that of the common CT equipment; therefore, the use of the Catphan motif to detect the CT part of PET/CT not only greatly increases the detection cost, but also can not obtain the ideal detection effect.

Thirdly, the current CT metrological verification regulations jjjg 961-. However, the background CT value of the detection module with low contrast resolution performance of the Catphan phantom CT is about 40HU under the tube voltage of 120kV (the most common detection condition), and the CT value of the water equivalent material is (0 +/-5) HU, so the background material of the low contrast resolution module of the Catphan phantom CT does not meet the water equivalent characteristic and does not meet the detection requirement of the CT low contrast resolution. In addition, the maximum diameter of the serial detection plug-in embedded in the Catphan motif low-contrast resolution module is 15mm, corresponding to the actual scanned image, a circular spot with the diameter of 15mm usually contains at most about 100 pixel points, and from the statistical viewpoint, if cnr (contrast ratio) calculation is performed, such sample amount cannot meet the statistical requirement, so that the objective evaluation result of low-contrast resolution is directly influenced, and the detection requirement cannot be met.

3. The current standards specify an image quality evaluation method: selecting cross-sectional images of hot balls and cold balls, drawing a region of interest (ROI) with a corresponding diameter on each ball, and drawing 12 ROIs with the same size as the ROI drawn on the ball on the background of an upper die body of the cross-sectional image of the center of the ball, as shown in FIG. 3; ROI are drawn on other layers at +/-1 cm and +/-2 cm positions on two sides of a tangent layer close to the center of the sphere; 60 background ROIs per size, 12 per layer, 5 layers; recording the average count of background on each ROI; and substituting the data into corresponding formulas to calculate various parameters such as contrast, background change rate and the like. In practical application of the evaluation method, there are the following problems:

PET/CT equipment produced by some manufacturers is provided with an image quality evaluation function, images can be analyzed according to the method, but the method is usually only suitable for data acquired by PET/CT equipment of the same brand model and needs to be carried out on an operating system provided with the PET/CT equipment; for the PET/CT equipment in hospitals, the process takes a long time, and the clinical diagnosis is seriously delayed when the machine is occupied for a long time.

If the PET/CT is not equipped with an operating system for data analysis or the PET/CT is not equipped with an image quality evaluation function, manual data acquisition and calculation are required to be carried out on the image according to an image quality evaluation method specified in the NEMA standard. Manual data acquisition requires manual selection of a section layer where a sphere center is located, a total of 360 ROIs are drawn in a background area according to the edge of each sphere in an image, and average counting in each ROI is recorded, so that the process is extremely complicated, time is consumed, and human errors are introduced, so that the same data result is different, and objective evaluation on the image quality of equipment cannot be performed.

4. Since PET devices perform functional metabolic imaging using radionuclides as imaging agents, each performance measurement of PET/CT requires the use of a radiopharmaceutical configured phantom. Because the NEMA IEC Body die Body has design defects, the pulmonary plug-in can not be fixed on the lower bottom of the die Body or in a clamping groove of a top cover, and the density of the pulmonary plug-in is far less than that of water, when the die Body is subjected to radiopharmaceutical configuration, the pulmonary plug-in is easy to float on the surface of a solution and is difficult to install, the dispensing time is prolonged, and therefore the ionizing radiation dose received by experimenters is increased. In addition, the half-life of the radionuclide in the FDG solution is short, and the phantom needs to be reconfigured if the dosing time is too long, which results in the drug activity not meeting the minimum activity requirement for the phantom.

In view of the above-mentioned defects existing in the existing mold body, the inventor of the present invention has made continuous research and design, and after repeatedly trying out samples and improving, finally, has created the utility model with practical value.

Disclosure of Invention

An object of the utility model is to overcome the defect that current die body exists, and provide a PET/CT performance detection die body, make its image quality that satisfies small focus detect the requirement, improve and detect the precision to it is more practical.

The utility model discloses a another aim at overcomes the defect that current die body exists, and provides a PET/CT performance detection die body, and the technical problem that solve makes its CT that satisfies PET/CT equipment low contrast resolution detection demand, improves and detects the precision to be suitable for the practicality more.

Another object of the present invention is to provide a PET/CT performance detecting mold, which is simple in structure and easy to use, and is more practical.

The utility model discloses a still another aim at provides a PET/CT performance detection die body, and the technical problem that solve changes the operation when making its medicine configuration, reduces the time of dispensing to the ionizing radiation that the experimenter received has been reduced, thereby is suitable for the practicality more.

The utility model discloses a still another aim at provides a PET/CT performance detection die body, and the technical problem that solve makes its a scan can realize the detection of multinomial parameters such as PET image quality, CT low contrast resolution, PET/CT registration accuracy, and length and experimental error when avoiding the multiple scanning because of the increase that factors such as die body locating position difference, repeatability error cause the detection to be suitable for the practicality more.

The utility model discloses a still another aim at provides a PET/CT performance detection die body, and the technical problem that solve makes its CT low contrast resolution detection module, and after the actual formation of image, the pixel is enough in the low contrast plug-in components, accords with the statistics requirement, can carry out objective evaluation.

The purpose of the utility model and the technical problem thereof are realized by adopting the following technical scheme. The basis the utility model provides a PET/CT performance detection die body, including PET image quality detection module and CT performance detection module, wherein the PET image quality detection module that is located the upper portion passes through bolted connection with the CT performance detection module that is located the lower part and is a whole.

In the PET/CT performance detection mold body, the PET image quality detection module is a cavity structure and is composed of a hollow sphere, a top cover of the PET image quality detection module, a lung plug-in, an upper bottom of the PET image quality detection module, and a lower bottom of the PET image quality detection module; the cross section of the PET image quality detection module is in a shape imitating a trunk;

the PET image quality detection module top cover is fixed on the upper bottom and the upper surface of the PET image quality detection module through bolts, a lung plug-in top cover groove is formed in the middle of the lower surface of the PET image quality detection module top cover, a lung plug-in lower groove is formed in the middle of the lower bottom of the PET image quality detection module, the lung plug-in is located in the center of the PET image quality detection module, the lung plug-in is a hollow pipe and filled with foam, a PET image quality detection module top cover round hole with the same area as the lower end of the PET image quality detection module top cover is formed in the center of the upper bottom of the PET image quality detection module, and a PET image quality detection module upper bottom water injection hole for injecting water is formed in;

the upper part of the lung plug-in is inserted in a groove of a top cover of the lung plug-in, and the lower part of the lung plug-in is arranged in a groove of the lower bottom of the lung plug-in;

the hollow spheres are added by 2 besides 6 hollow spheres distributed according to standard specification, and the sphere centers of 8 hollow spheres are positioned on the same horizontal section; the inner diameters of the first hollow sphere, the second hollow sphere, the third hollow sphere, the fourth hollow sphere, the fifth hollow sphere and the sixth hollow sphere which are distributed according to the current standard are respectively 37mm, 28mm, 22mm, 17mm, 13mm and 10mm, and the inner diameters of the added 2 hollow spheres, namely the seventh hollow sphere and the eighth hollow sphere, are respectively 7mm and 4 mm; the centers of the seventh hollow ball and the eighth hollow ball are positioned on a circle with the diameter of 66mm and taking the central shaft of the lung plug-in piece cylinder as the circle center, the circle where the centers of the seventh hollow ball and the eighth hollow ball are positioned is concentric with the circle where the centers of the first hollow ball, the second hollow ball, the third hollow ball, the fourth hollow ball, the fifth hollow ball and the sixth hollow ball are positioned, the eighth hollow ball is positioned at 12 o 'clock, and the seventh hollow ball is positioned at 10 o' clock;

8 clean balls pass through the PET image quality detection module top cover round hole that sets up at PET image quality detection module upper base middle part through the capillary and link to each other with PET image quality detection module top cover. In the PET/CT performance detection mold body, the CT performance detection module is composed of a CT low-contrast resolution module, a CT performance detection module upper bottom, a CT performance detection module lower bottom, and a CT performance detection module bottom cover;

the CT low-contrast plugins penetrating through the CT low-contrast resolution module are distributed in a regular triangle and embedded into the background of the CT low-contrast resolution module, the CT low-contrast plugins are respectively a first CT low-contrast plugin, a second CT low-contrast plugin and a third CT low-contrast plugin, the low-contrast resolutions of the first CT low-contrast plugin, the second CT low-contrast plugin and the third CT low-contrast plugin are respectively 0.5%, 1.0% and 1.5%, and the diameters of the low-contrast plugins are the same;

the center of the upper bottom of the CT performance detection module is provided with an upper bottom groove of the CT performance detection module, and the upper part of the CT low-contrast resolution module is embedded in the upper bottom groove of the CT performance detection module; the outer edge of the upper bottom of the CT performance detection module and the outer edge of the lower bottom of the CT performance detection module are provided with 6 mutually corresponding through holes penetrating through the whole CT performance detection module, the outer edge of the lower bottom of the PET image quality detection module is provided with non-through holes corresponding to the through holes of the upper bottom of the 6 CT performance detection modules and the through holes of the lower bottom of the 6 CT performance detection modules, 6 long bolts penetrate through the through holes of the lower bottom of the 6 CT performance detection modules and the through holes of the upper bottom of the 6 CT performance detection modules and are fixed in the non-through holes of the lower bottom of the 6 PET image quality detection modules, and the PET image quality detection module and the CT performance detection modules are fixed together;

the CT performance detection module is characterized in that a CT performance detection module bottom round hole closely matched with a CT performance detection module bottom is formed in the center of the lower bottom of the CT performance detection module, the CT performance detection module bottom is screwed in the CT performance detection module bottom round hole in the lower bottom of the CT performance detection module through threads and connected into a whole, and a CT performance detection module lower water injection hole is formed in the lower bottom of the CT low-contrast resolution module.

In the PET/CT performance detection die body, the CT low-contrast resolution module is made of a non-metal CT artifact-free material, and is a cake-shaped module, and a background material of the CT low-contrast resolution module is water equivalent.

The PET/CT performance detection phantom is characterized in that the hollow spheres are hot spheres and cold spheres, wherein the third hollow sphere, the fourth hollow sphere, the fifth hollow sphere, the sixth hollow sphere, the seventh hollow sphere and the eighth hollow sphere are hot spheres, the first hollow sphere and the second hollow sphere are cold spheres, all the hot spheres are filled with fluorodeoxyglucose solution, the fluorodeoxyglucose solution in the hot spheres has the same activity concentration, all the cold spheres are filled with pure water, and the activity concentration of the fluorodeoxyglucose solution filled in the PET image quality detection module cavity is 1/4 of the activity concentration of the fluorodeoxyglucose solution in the hot spheres.

Compared with the prior art, the utility model obvious advantage and beneficial effect have. It has at least the following advantages:

1. the utility model discloses can be used to the accuracy detection and the PET CT registration accuracy detection that PET image quality detected, scattering correction and attenuation were rectified, can realize the whole detection items of NEMA IEC Body die Body, in addition, increase two internal diameters and be 7mm and 4 mm's clean shot respectively, not only can detect the PET image quality of small focus, can also roughly carry out qualitative aassessment to spatial resolution simultaneously.

2. The utility model discloses can be used to detect the low contrast resolution of CT, the low contrast resolution of CT detects this substrate material water equivalence of module is good, after injecting water in the die body, takes place partial volume effect when having avoided the formation of image of different materials, reduces experimental error.

And 3, the diameter of the CT low-contrast resolution plug-in is large enough, after actual imaging, the number of pixel points in the low-contrast plug-in is enough, the statistical requirement is met, the requirement of the objective evaluation method for the CT low-contrast resolution can be met, the CT low-contrast resolution can be respectively 1.5%, 1.0% and 0.5%, and the detection requirements of PET/CT of different grades are met.

The CT performance detection module can generate a CT image of water or water equivalent tissue large enough to detect the uniformity of the CT image.

5. The utility model can realize the detection of multiple parameters such as PET image quality, scattering correction and attenuation correction accuracy, PET/CT registration precision, CT low contrast resolution, CT image uniformity and the like at the same time by one-time scanning; the method avoids the increase of detection time and experimental error due to factors such as die body arrangement position difference and repeatability error in multiple scanning.

6. The utility model adopts a PET/CT performance detection mold body and an image evaluation method, which can automatically analyze and process the image quality of the data collected by PET/CT devices of different brands and models; can realize PET image quality, scattering correction and attenuation correction accuracy and the automatic analysis and the calculation of PET/CT registration accuracy, the software not only is applicable to the utility model discloses the die Body still can be used to NEMA IEC Body die Body. The off-line analysis can be realized, and the time of a PET/CT device is not occupied.

7. The utility model discloses when carrying out the configuration of radiopharmaceutical, the plug-in components of lung can the snap-on be in PET image quality detection module goes to the bottom draw-in groove or top cap draw-in groove, avoided the plug-in components of lung to be less than water because of density and float and lead to the die body installation difficulty in the die body for the operation is changeed in die body configuration process, makes the time of dispensing shorten, reduces the ionizing radiation dose to the experimenter, effectively alleviates the ionizing radiation that the process of dispensing caused to the experimenter.

8. The utility model discloses a die body design is detachable design, but each test section exclusive use also can make up the use.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a diagram of the data analysis method specified in the NEMA standard.

FIG. 2 is an external schematic view of the PET/CT performance detecting mold body of the present invention.

FIG. 3 is a cross-sectional view of the PET/CT performance detecting mold body of the present invention.

Fig. 4 is a distribution diagram of the position of the hollow sphere of the horizontal section of the hollow sphere center of the present invention.

Figure 5A is the utility model discloses PET image quality detection module top cap cuts open the picture with the clean shot.

Fig. 5B is the utility model discloses PET image quality detection module top cap and clean shot spatial structure schematic diagram.

Fig. 6 is the utility model discloses PET image quality detection module upper base structure sketch map.

Fig. 7 is the utility model discloses PET image quality detection module goes to the bottom structure sketch map.

Fig. 8 is an internal structure diagram of the PET image quality detection module of the present invention.

Fig. 9 is a top view of the CT performance detection module of the present invention.

Fig. 10A is a plan view of the CT low contrast resolution module of the present invention.

Fig. 10B is a perspective view of the CT low contrast resolution module of the present invention.

Fig. 11 is the bottom schematic view of the CT performance testing module of the present invention.

Fig. 12 is a schematic view of the bottom cover of the CT performance testing module of the present invention.

Fig. 13 is the internal structure diagram of the CT performance testing module after the installation.

Fig. 14 is an internal structure schematic diagram of the PET/CT performance detection die body of the present invention.

Fig. 15 is a framework diagram of the image quality analysis process of the present invention.

Figure 16 is a bar graph comparing test results of the same PET/CT apparatus using the present invention and the nemiec Body phantom, respectively.

Figure 17 uses the utility model discloses carry out image quality to three different PET/CT equipment and detect contrast histogram.

FIG. 18: the Catphan phantom was used to detect CT low contrast resolution images under the micromirror.

FIG. 19: and (3) verifying the equivalence of the bottom water of the CT low-contrast resolution module under the micromirror.

Wherein: the left image is the image without water filling, and the right image is the image after water filling.

FIG. 20: use the utility model discloses the CT low contrast resolution power image under the measuring micromirror.

FIG. 21: pure water and CT low contrast resolution module background boundary position noise measurement effect graph under the micro-mirror.

FIG. 22: three modes under the micro-mirror are used for collecting images according to the image uniformity CT value.

a: background, b: boundary, c: pure water

FIG. 23. interface diagram analysis of PET image quality under micromirror and accuracy of scatter correction and attenuation correction.

FIG. 24 is a PET/CT registration accuracy analysis interface diagram under the micromirror.

Wherein:

1: PET image quality detection module

1-1: first hollow sphere 1-2: second hollow sphere

1-3 parts of third hollow sphere and 1-4 parts of fourth hollow sphere

1-5 parts of fifth hollow sphere and 1-6 parts of sixth hollow sphere

1-7 parts of seventh hollow sphere and 1-8 parts of eighth hollow sphere

1-9: lung plug-in

1-10: a top cover of the PET image quality detection module,

1-10-1: lung plug-in top cover groove

1-11: the upper bottom of the PET image quality detection module,

1-11-1: a top cover round hole of the PET image quality detection module,

1-11-2: PET image quality detection module upper bottom water injection hole

1-12: PET image quality detection module goes to bottom

1-12-1: lung plug-in components recess that goes to bottom

2: CT performance detection module

2-1: CT low contrast resolution module

2-1-1: first CT low contrast insert 2-1-2: second CT Low contrast plug-in

2-1-3: third CT Low contrast plug-in

2-2: CT performance detection module upper bottom

2-2-1: upper bottom groove of CT performance detection module

2-3: lower bottom of CT performance detection module

2-3-1: lower bottom water injection hole of CT performance detection module

2-3-2: CT performance detection module bottom round hole

2-4: CT performance detection module bottom cover

Detailed Description

To further illustrate the technical means and effects of the present invention for achieving the objectives of the present invention, the following detailed description of the embodiments, structures, methods and steps of the PET/CT performance detecting mold body according to the present invention is provided with the accompanying drawings and the preferred embodiments.

Referring to fig. 2-14, a PET/CT performance detecting mold body according to a preferred embodiment of the present invention mainly includes: a PET image quality detection module 1 and a CT performance detection module 2, wherein: wherein the PET image quality detecting module 1 located at the upper portion and the CT performance detecting module 2 located at the lower portion are connected as a whole by bolts (as shown in fig. 2).

Referring to fig. 3, the PET image quality detection module is designed based on a detection method regarding image quality in the current standards at home and abroad. The PET image quality detection module 1 is of a cavity structure, and the inner height is 180 mm. The cross section of the die body is in a shape imitating a trunk, and the wall thickness of the die body is 3 mm. The PET image quality detection module 1 is composed of hollow spheres, a PET image quality detection module top cover 1-10, lung inserts 1-9, a PET image quality detection module upper bottom 1-11 and a PET image quality detection module lower bottom 1-12.

Referring to fig. 4, 5A and 5B, the hollow spheres are used for detecting PET image quality, except for 6 hollow spheres specified by the current standard, an eighth hollow sphere 1-8 with an inner diameter of 4mm and a seventh hollow sphere 1-7 with an inner diameter of 7mm are added at positions close to lung inserts 1-9 to detect image quality of a micro-lesion, the 6 hollow spheres are respectively a sixth hollow sphere 1-6 with an inner diameter of 10mm, a fifth hollow sphere 1-5 with an inner diameter of 13mm, a fourth hollow sphere 1-4 with an inner diameter of 17mm, a third hollow sphere 1-3 with an inner diameter of 22mm, a second hollow sphere 1-2 with an inner diameter of 28mm and a first hollow sphere 1-1 with an inner diameter of 37mm according to the current standard, wall thicknesses of all the hollow spheres are not greater than 1mm, and sphere centers of all the hollow spheres are located on the same horizontal cross section, as shown in fig. 5A and 5B. As the spheres are filled with radioactive solution in the detection process, if the distances among the hollow spheres are too close, mutual interference can be caused, so that the spherical centers 1-7 and 1-8 of the seventh hollow sphere are positioned on a circle which takes the axis of the lung plug-in 1-9 as the center and has the diameter of 66mm, the circle is concentric with the circles where the spherical centers of the first hollow sphere 1-1, the second hollow sphere 1-2, the third hollow sphere 1-3, the fourth hollow sphere 1-4, the fifth hollow sphere 1-5 and the sixth hollow sphere are positioned, the spherical centers of the 1-8 of the eighth hollow sphere are positioned at 12 o 'clock position, and the spherical centers 1-7 of the seventh hollow sphere are positioned at 10 o' clock position; the position distribution of the 8 hollow spheres can not generate mutual interference, and the simulation of the micro focus can be realized while the current standard is met, so that the aim of image quality detection is fulfilled. The horizontal cross section where the sphere centers of all the hollow spheres are located is 70mm away from the lower surface of the PET image quality detection module top cover 1-10, and all the hollow spheres are connected with the PET image quality detection module top cover 1-10 through capillaries.

The hollow ball is divided into a hot ball and a cold ball, and other 6 balls are hot balls except that the first hollow ball and the second hollow ball are cold balls.

Referring to fig. 5A, 5B and 8, the diameter of the upper surface of the top cover 1-10 of the PET image quality detection module is 190mm, the diameter of the lower surface of the top cover 1-10 of the PET image quality detection module is 154mm, and a lung inserter top cover groove 1-10-1 with a diameter of 50mm is formed in the center of the lower surface of the top cover 1-10 of the PET image quality detection module and is used for connecting the lung inserter 1-9, as shown in fig. 7. The lung inserts 1-9 are located in the center of the PET image quality detection module 1, and the interior of a hollow tube with an outer diameter of 50mm and a wall thickness of 4mm is filled with foam for simulating lung attenuation.

Referring to fig. 6, a top cover circular hole 1-11-1 of the PET image quality detection module, which has the same area as the lower end of the top cover 1-10 of the PET image quality detection module, is formed in the center of the upper bottom 1-11 of the PET image quality detection module, the top cover circular hole 1-11-1 of the PET image quality detection module is completely and closely matched with the top cover 1-10 of the PET image quality detection module, and two top water injection holes 1-11-2 of the PET image quality detection module are formed in the upper bottom 1-11 of the PET image quality detection module and used for injecting water.

Referring to fig. 7, the center of the lower bottom 1-12 of the PET image quality detection module is provided with a lower groove 1-12-1 of the pulmonary inserter with a diameter of 50mm for installing the pulmonary inserter 1-9. After the top cover 1-10 of the PET image quality detection module is arranged on the upper bottom 1-11 of the PET image quality detection module and is fixed by small bolts, the upper end of the lung plug-in 1-9 is clamped in the lower bottom groove 1-12-1 of the lung plug-in and the lower end of the lung plug-in 1-9 is clamped in the lower bottom groove 1-12-1 of the lung plug-in. The bottom of the PET image quality detection module 1 is provided with 6 non-through threaded holes for connecting the CT performance detection module 2. The bottom of the PET image quality detection module 1 is connected with the CT performance detection module 2 through 6 bolts in a downward connection mode.

Referring to fig. 9-14, the CT performance detection module 2 is similar to the PET image quality detection module 1 in structure, and has the same cross section. The CT performance detection module 2 consists of a CT low-contrast resolution module 2-1, a CT performance detection module upper bottom 2-2, a CT performance detection module lower bottom 2-3 and a CT performance detection module bottom cover 2-4.

Referring to fig. 9, the height of the cavity of the CT performance detection module 2 is 19.5mm, and the center of the upper bottom 2-2 of the CT performance detection module is provided with an upper bottom groove 2-2-1 of the CT performance detection module, which has a diameter of 150mm and a depth of 0.5mm, for embedding the CT low-contrast resolution module 2-1.

Referring to fig. 10A and 10B, the CT low contrast resolution module 2-1 is made of non-metal material without CT artifacts and is a pie module with a diameter of 150mm and a thickness of 20 mm. The background material water equivalent of the CT low-contrast resolution module 2-1 is good, 3 CT low-contrast plug-ins penetrating through the CT low-contrast resolution module 2-1 are distributed in a regular triangle and embedded in the background of the CT low-contrast resolution module 2-1, the CT low-contrast resolutions corresponding to the 3 CT low-contrast plug-ins are respectively 0.5% for the first CT low-contrast plug-in 2-1-1, 1.0% for the second CT low-contrast plug-in 2-1-2 and 1.5% for the third CT low-contrast plug-in 2-1-3, the diameters of the 3 CT low-contrast plug-ins are all 20mm, and therefore when objective evaluation is carried out on the CT low-contrast resolutions, enough pixel points are arranged in the CT low-contrast plug-ins.

Referring to fig. 11, the lower bottom 2-3 of the CT performance testing module is provided with two water injection holes 2-3-1 for injecting water, the middle of the lower bottom 2-3 of the CT performance testing module is provided with a circular hole 2-3-2 of the CT performance testing module bottom cover with the diameter of 170mm, and the circular hole 2-3-2 of the CT performance testing module bottom cover is closely matched with the circular hole 2-4 of the CT performance testing module bottom cover.

Referring to FIG. 12, the diameter of the upper surface of the bottom cover 2-4 of the CT performance testing module is 170mm, and the diameter of the lower surface is 180 mm. The circular hole 2-3-2 of the CT performance detection module bottom cover is in threaded connection with the CT detection module bottom cover 2-4.

Referring to fig. 13 and 14, the center of the upper bottom 2-2 of the CT performance detection module is provided with an upper bottom groove 2-2-1 of the CT performance detection module, and the upper part of the CT low-contrast resolution module 2-1 is embedded in the upper bottom groove 2-2-1 of the CT performance detection module; the outer edge of the upper bottom 2-2 of the CT performance detection module and the outer edge of the lower bottom 2-3 of the CT performance detection module are provided with 6 mutually corresponding through holes penetrating through the whole CT performance detection module 2, the outer edge of the lower bottom 1-12 of the PET image quality detection module is provided with non-through holes corresponding to the through holes of the upper bottom 2-2 of the 6 CT performance detection modules and the through holes of the lower bottom 2-3 of the 6 CT performance detection modules, 6 long bolts penetrate through the through holes of the lower bottoms 2-3 of the 6 CT performance detection modules and the through holes of the upper bottom 2-2 of the 6 CT performance detection modules and are fixed in the non-through holes of the lower bottoms 1-12 of the 6 PET image quality detection modules, and the PET image quality detection module 1 and the CT performance detection module 2 are fixed together;

the center of the lower bottom 2-3 of the CT performance detection module is provided with a circular hole 2-3-2 of the CT performance detection module bottom closely matched with the bottom 2-4 of the CT performance detection module, the CT performance detection module bottom 2-4 is screwed in the circular hole 2-3-2 of the CT performance detection module bottom 2-3 of the CT performance detection module bottom and is connected into a whole, and the lower bottom 2-3 of the CT performance detection module is provided with a water injection hole 2-3-1 of the lower bottom of the CT low-contrast resolution module.

Referring to fig. 15, the matched image quality analysis module programs the data analysis methods specified in the current standards to perform automated analysis and calculation of PET image quality, scatter correction, and attenuation correction accuracy; and finding the sphere center in the PET image by calculating the center of gravity of the hot sphere, and finding the sphere center in the CT image by fitting the sphere edge so as to complete the calculation of the PET/CT registration accuracy. The image evaluation method of the PET/CT performance detection motif mainly comprises the following steps:

step 100: initially, step 200 is performed;

step 200: importing image data, and importing PET/CT Dicom image data into an image import module; after completion, step 300 is executed;

step 300: displaying images, namely displaying a PET image 310, a CT image 320 and a PET/CT fusion image 330 in an image display module; after the completion, selecting to execute the step 400 or 600;

step 400: delineating the ROI according to NEMA standard in an image ROI region selection module, wherein the delineation comprises the following steps: 1-8 parts of eighth hollow spheres, 1-7 parts of seventh hollow spheres, 60 parts of 7 mm-diameter circular background ROIs, 1-6 parts of sixth hollow spheres, 60 parts of 10 mm-diameter circular background ROIs, 1-5 parts of fifth hollow spheres, 60 parts of 13 mm-diameter circular background ROIs, 1-4 parts of fourth hollow spheres, 60 parts of 17 mm-diameter circular background ROIs, 1-3 parts of third hollow spheres, 60 parts of 22 mm-diameter circular background ROIs, 1-2 parts of second hollow spheres, 60 parts of 28 mm-diameter circular background ROIs, 1-1 parts of first hollow spheres, 60 parts of 37 mm-diameter circular background ROIs and 1-9 ROIs with 30 mm-diameter circular lung inserts; after completion, step 500 is performed;

step 500: recording the intra-ROI counts, recording the intra-ROI counts in step 400; after completion, step 510 and step 520 are executed;

step 510: evaluating the quality of the PET image, and calculating the contrast and background change rate of each hot ball and each cold ball in a PET image quality module according to a PET image quality evaluation formula specified in a NEMA standard; after completion, step 515 is performed;

step 515: displaying the PET image quality evaluation result, and displaying the contrast and background change rate of each hot ball and each cold ball;

step 520: evaluating the accuracy of the scattering correction and the attenuation correction, and calculating the lung residual error in a calibration accuracy evaluation module according to a scattering correction and attenuation correction accuracy evaluation formula specified in a NEMA standard; after completion, go to step 525;

step 525: displaying the evaluation results of the accuracy of the scattering correction and the attenuation correction, and displaying the residual error of the lung;

step 600: drawing a hot ball ROI, and drawing an ROI of a sixth hollow ball 1-6, an ROI of a fifth hollow ball 1-5, an ROI of a fourth hollow ball 1-4 and an ROI of a third hollow ball 1-3 in the image ROI area selection module; after completion, step 610 and step 620 are executed;

step 610: calculating the center of a PET hot ball, and calculating the center of a sixth hollow ball 1-6, the center of a fifth hollow ball 1-5, the center of a fourth hollow ball 1-4 and the center of a third hollow ball 1-3 by adopting a threshold segmentation algorithm; after completion, step 700 is performed;

step 620: calculating the center of the CT hot ball, and calculating the center of a sixth hollow ball 1-6, the center of a fifth hollow ball 1-5, the center of a fourth hollow ball 1-4 and the center of a third hollow ball 1-3 by using an RANSAC algorithm; after completion, step 700 is performed;

step 700: in a PET/CT registration precision evaluation module, calculating the deviation between the center of a PET hot ball and the center of a CT hot ball according to IEC standard, and calculating the deviation between the center of a PET ball and the center of a CT ball of a sixth hollow ball 1-6, a fifth hollow ball 1-5, a fourth hollow ball 1-4 and a third hollow ball 1-3; after completion, 800 is performed;

step 800: and displaying the configuration precision result of the PET/CT, and displaying the deviation of the PET spherical center and the CT spherical center of the sixth hollow sphere 1-6, the fifth hollow sphere 1-5, the fourth hollow sphere 1-4 and the third hollow sphere 1-3.

The PET image quality detection module is configured with radiopharmaceuticals as specified in the image quality detection methods of the current standards. Wherein the spheres of the first hollow sphere 1-1 and the second hollow sphere 1-2 are filled with pure water as cold spheres, and the spheres of the third hollow sphere 1-3, the fourth hollow sphere 1-4, the fifth hollow sphere 1-5 and the sixth hollow sphere 1-6 are filled with fluorodeoxyglucose solution (FDG solution) as hot spheres, the utility model discloses the spheres of the seventh hollow sphere 1-7 and the eighth hollow sphere 1-8 that increase are filled with FDG solution as hot spheres, and the activity concentration of fluorodeoxyglucose solution (FDG solution) in all hot spheres is the same. The middle part of the PET image quality detection module 1 is inserted with pulmonary plug-ins 1-9, and the cavity of the PET image quality detection module 1 is filled with fluorodeoxyglucose solution (FDG solution), wherein the activity concentration is 1/4 of the fluorodeoxyglucose solution (FDG solution) in the hot bulb.

And filling pure water into the CT performance detection module 2, and fixing the PET image quality detection module 1 and the CT performance detection module 2 through 6 bolts. The phantom is placed flat on an examination couch and scanned using a conventional PET/CT scanning protocol. After scanning and image reconstruction end, copy data to built-in from PET/CT operating system the utility model discloses both can end data acquisition in the computer of image quality analysis software.

The PET image is imported into image quality analysis software, so that the automatic analysis and processing of the PET image quality, the scattering correction and the attenuation correction accuracy can be carried out, and a calculation result is given. After the PET image and the CT image are respectively imported into image quality analysis software, the PET/CT registration precision can be calculated and a calculation result is given. And reading the CT image and evaluating the low contrast resolution of the CT. The experimental results obtained are as follows:

verification of the detection function of the PET image quality and of the accuracy of the scatter correction and attenuation correction

The actual detection result shows, the utility model discloses can realize PET image quality and scattering correction and the detection of decay correction accuracy according to the regulation of current standard. Use respectively the utility model discloses and NEMA IEC Body die Body carries out the detection of PET image quality and scattering correction and decay correction accuracy to same PET CT equipment, as shown in table 1 and fig. 16, to same detection project, the utility model discloses and the testing result of NEMA IEC Body die Body have comparability.

TABLE 1 detection of the same PET/CT equipment using the utility model and NEMA IEC Body model

Use the utility model discloses PET CT to many different brand models carries out the performance detection, and the actual testing result shows, the utility model discloses can realize the detection of small focus image quality to can carry out obvious grade division to the ability that different equipment presented small focus image, like table 2 and figure 17. In addition, combine table 1 and fig. 17 to know, the image quality of small focus detects and can not produce the interference to the conventional image quality detection of current standard, promptly the utility model discloses can realize the image quality detection of small focus when according with current standard.

TABLE 2. use the utility model discloses carry out image quality to three different PET/CT equipment and detect

Injecting: A. and B, the two devices can not detect the 4mm small balls, so that the data of the 4mm small balls are null.

CT performance detection functional verification

The CT low contrast resolution is presented by measuring and calculating the difference between the CT values of the background in and around the CT low contrast resolution insert, with a difference of 10HU for low contrast resolution of 1.0% and a difference of 5HU for low contrast resolution of 0.5%. Heretofore, the CT low contrast resolution module is usually used for detection using a Catphan phantom, which does not satisfy the water equivalent characteristics of the background material, does not meet the detection requirements of the CT low contrast resolution (see table 3), has a large difference with the CT value of the surrounding cladding material, and causes a partial volume effect during the co-imaging, resulting in a large error when measuring the difference between the CT values of the backgrounds in and around the CT low contrast resolution insert, as shown in fig. 18.

TABLE 3 CATphan motif CT Low contrast resolution Module background and in-card CT values

Position of	Background ROI1	Background ROI2	1.0% low contrast insert
				CT number (HU)	37.58	38.79	49.19

The utility model discloses can scan the detection that realizes PET image quality, CT low contrast resolution isoparametric in step, shorten check-out time by a wide margin. The material-water equivalence of the CT low-contrast resolution module substrate is good, in a CT image, the CT low-contrast resolution module background can be almost integrated with pure water in a die body, and partial volume effect of surrounding cladding materials and module background materials due to large difference of CT values is avoided, as shown in figure 19. The diameters of the 3 CT low-contrast plug-ins are all 20mm, so that when objective evaluation is carried out on the CT low-contrast resolution, the number of pixel points in the plug-ins is far larger than 100, and the statistical requirement is met; equal area ROIs were drawn inside and around the 3 inserts and the CT value and standard deviation SD within each ROI were measured as shown in fig. 20. The difference between the CT values and the CNR (contrast to noise ratio) are calculated, and the results are shown in Table 4, the CT low-contrast resolution corresponding to 3 plugins is 1.5%, 1.0% and 0.5%, respectively, and the detection requirements of PET/CT of different grades can be met.

TABLE 4 CT Low contrast resolution test results

Filling the CT performance detection module with water, and measuring the CT values and standard deviations SD of the background boundary positions of pure water and the CT low-contrast resolution module and the background central position (shown in figure 21) in a CT actual imaging picture; CT value and standard deviation of the low contrast resolution module background central point of CT and boundary position and CT and standard deviation do not have obvious difference, and noise level is lower, like table 5, promptly the utility model discloses can obtain the even image of large area water or equivalent tissue, the event the utility model discloses the low contrast resolution detection module of CT can also be used for the detection of CT image homogeneity. CT value measurements were performed in the CT low contrast resolution module background, CT low contrast resolution module background and water junction location, pure water, respectively, as shown in fig. 22. The measurement results show that the difference between the CT value of the CT low-contrast resolution module background and the pure water CT value is about 3HU, the difference between the CT value of the CT low-contrast resolution module background and the water junction position and the pure water CT value is about 2.5HU, the water equivalent requirement is met, and the difference between the computed CT image uniformity results under the three acquisition modes is small, as shown in Table 6.

TABLE 5 CT values and SD measurements of background junction of pure water and CT low contrast resolution modules

TABLE 6 CT image homogeneity measurements

3. Software functional verification

The utility model discloses the image quality analysis software who is equipped with can realize PET image quality parameter and scatter correction and decay automatic analysis and calculation of correction accuracy to show above-mentioned testing result with the mode of contrast, background rate of change, lung residual error, as figure 23; sphere center positioning of spheres in PET and CT images can be achieved to calculate PET/CT registration accuracy, as in fig. 24. In addition, software does not rely on PET/CT operating system, is not only applicable to the utility model discloses, still can be used to NEMA IEC Body die Body to can carry out analysis processes to the PET/CT detection data of each model of each brand, have the universality.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above description, and although the present invention has been disclosed with the preferred embodiment, it is not limited to the present invention, and any skilled person in the art can make modifications or changes equivalent to the equivalent embodiment without departing from the scope of the present invention, but all the modifications, equivalent changes and modifications of the above embodiments by the technical spirit of the present invention still fall within the scope of the present invention.

Claims (5)

1. A PET/CT performance detection die body is characterized in that: the device comprises a PET image quality detection module (1) and a CT performance detection module (2), wherein the PET image quality detection module (1) positioned at the upper part and the CT performance detection module (2) positioned at the lower part are connected into a whole through bolts.

2. The PET/CT performance detection phantom according to claim 1, wherein the PET image quality detection module (1) has a cavity structure and is composed of a hollow sphere, a PET image quality detection module top cover (1-10), a lung plug-in (1-9), a PET image quality detection module upper bottom (1-11) and a PET image quality detection module lower bottom (1-12); the cross section of the PET image quality detection module (1) is in a shape imitating a trunk;

wherein, a top cover (1-10) of the PET image quality detection module is fixed on the upper top surface of an upper bottom (1-11) of the PET image quality detection module through bolts, a lung inserter top cover groove (1-10-1) is arranged in the middle of the lower surface of the top cover (1-10) of the PET image quality detection module, a lung inserter lower bottom groove (1-12-1) is arranged in the middle of a lower bottom (1-12) of the PET image quality detection module, the lung inserter (1-9) is a hollow tube which is filled with foam, a PET image quality detection module top cover round hole (1-11-1) with the same area as the lower end of the top cover (1-10) of the PET image quality detection module is arranged in the center of the upper bottom (1-11) of the PET image quality detection module, the upper bottom (1-11) of the PET image quality detection module is provided with water injection holes (1-11-2) for injecting water into the upper bottom of the PET image quality detection module;

the upper part of the lung plug-in (1-9) is inserted in the groove (1-10-1) of the top cover of the lung plug-in, and the lower part of the lung plug-in (1-9) is arranged in the groove (1-12-1) of the lower bottom of the lung plug-in;

the hollow spheres are added by 2 besides 6 hollow spheres distributed according to standard specification, and the sphere centers of 8 hollow spheres are positioned on the same horizontal section; the inner diameters of a first hollow sphere (1-1), a second hollow sphere (1-2), a third hollow sphere (1-3), a fourth hollow sphere (1-4), a fifth hollow sphere (1-5) and a sixth hollow sphere (1-6) which are distributed according to the current standard are 37mm, 28mm, 22mm, 17mm, 13mm and 10mm respectively, and the inner diameters of the added 2 hollow spheres, namely a seventh hollow sphere (1-7) and an eighth hollow sphere (1-8), are 7mm and 4mm respectively; the spherical centers of the seventh hollow ball (1-7) and the eighth hollow ball (1-8) are positioned on a circle which takes the central shaft of the cylinder of the lung plug-in piece (1-9) as the center and has a diameter of 66mm, the circle where the spherical centers of the seventh hollow ball (1-7) and the eighth hollow ball (1-8) are positioned is concentric with the circle where the spherical centers of the first hollow ball (1-1), the second hollow ball (1-2), the third hollow ball (1-3), the fourth hollow ball (1-4), the fifth hollow ball (1-5) and the sixth hollow ball (1-6) are positioned, the eighth hollow ball (1-8) is positioned at 12 o 'clock, and the seventh hollow ball (1-7) is positioned at 10 o' clock;

8 hollow balls penetrate through a top cover round hole (1-11-1) of the PET image quality detection module arranged in the middle of the upper bottom (1-11) of the PET image quality detection module through a capillary tube and are connected with a top cover (1-10) of the PET image quality detection module.

3. The PET/CT performance detection phantom according to claim 1, wherein the CT performance detection module (2) is composed of a CT low contrast resolution module (2-1), a CT performance detection module upper bottom (2-2), a CT performance detection module lower bottom (2-3), and a CT performance detection module bottom cover (2-4);

the CT low-contrast plugins penetrating through the CT low-contrast resolution module (2-1) are distributed in a regular triangle and embedded into the background of the CT low-contrast resolution module (2-1), the CT low-contrast plugins are a first CT low-contrast plugin (2-1-1), a second CT low-contrast plugin (2-1-2) and a third CT low-contrast plugin (2-1-3), the low-contrast resolutions of the first CT low-contrast plugin (2-1-1), the second CT low-contrast plugin (2-1-2) and the third CT low-contrast plugin (2-1-3) are 0.5%, 1.0% and 1.5%, and the diameters of the CT low-contrast plugins are the same;

the center of the upper bottom (2-2) of the CT performance detection module is provided with an upper bottom groove (2-2-1) of the CT performance detection module, and the upper part of the CT low-contrast resolution module (2-1) is embedded in the upper bottom groove (2-2-1) of the CT performance detection module; the outer edge of the upper bottom (2-2) of the CT performance detection module and the outer edge of the lower bottom (2-3) of the CT performance detection module are provided with 6 mutually corresponding through holes which penetrate through the whole CT performance detection module (2), non-through holes corresponding to the through holes of the upper bottom (2-2) of the 6 CT performance detection modules and the through holes of the lower bottom (2-3) of the 6 CT performance detection modules are arranged at the outer edges of the lower bottoms (1-12) of the PET image quality detection modules, 6 long bolts penetrate through holes of 6 lower bottoms (2-3) of the CT performance detection modules and through holes of 6 upper bottoms (2-2) of the CT performance detection modules and are fixed in non-through holes of 6 lower bottoms (1-12) of the PET image quality detection modules, and the PET image quality detection modules (1) and the CT performance detection modules (2) are fixed together;

the center of the lower bottom (2-3) of the CT performance detection module is provided with a CT performance detection module bottom round hole (2-3-2) which is closely matched with the CT performance detection module bottom cover (2-4), the CT performance detection module bottom cover (2-4) is screwed in the CT performance detection module bottom cover round hole (2-3-2) of the lower bottom (2-3) of the CT performance detection module through threads and is connected into a whole, and the lower bottom (2-3) of the CT performance detection module is provided with a CT low-contrast-resolution module bottom water injection hole (2-3-1).

4. The PET/CT performance detection phantom according to claim 3, wherein said CT low contrast resolution module (2-1) is made of non-metallic CT artifact free material, and is a pie-shaped module, and the background material of the CT low contrast resolution module (2-1) is water equivalent.

5. The PET/CT performance detection phantom according to claim 2, wherein the hollow spheres are hot spheres and cold spheres, wherein the third hollow ball (1-3), the fourth hollow ball (1-4), the fifth hollow ball (1-5), the sixth hollow ball (1-6), the seventh hollow ball (1-7) and the eighth hollow ball (1-8) are hot balls, the first hollow ball (1-1) and the second hollow ball (1-2) are cold balls, the fluorodeoxyglucose solution is filled in all the hot sphere bodies, the activity concentration of the fluorodeoxyglucose solution in the hot sphere bodies is the same, pure water is filled in all the cold spheres, and the cavity of the PET image quality detection module (1) is filled with the fluorodeoxyglucose solution with the activity concentration being 1/4 of the activity concentration of the fluorodeoxyglucose solution in the hot spheres.

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