A CT spiral scanning multi-planar reconstruction image axial performance test phantom

Abstract

The invention relates to a CT scanning and reconstructing image axial performance test phantom, the main body of which is an organic glass cube or a cuboid, tungsten beads and tungsten wires for measuring the spatial resolution of CT spiral scanning and reconstructing images are respectively arranged in the main body along the three axes of X, Y and Z, 1 to 5 metal wires for measuring the layer thickness deviation of CT spiral scanning and reconstructing images are arranged on six surfaces of the main body, the metal wires are all obliquely arranged on the surface where they are located, equidistant, parallel and centrally symmetrically arranged, the highest end of the metal wire located below and the lowest end of the adjacent metal wire located above are on the same horizontal line, and the angle between the metal wire and the relevant surface is 18.4° to 45°. The invention has reasonable design, simple structure, firmness and reliability, convenient use and easy maintenance, can meet the requirements of CT spiral scanning multi-plane reconstructing image axial performance test, and can also be used for measuring CT axial scanning and reconstructing image performance.

Description

Technical Field

[0001] The present invention relates to the technical field of medical CT scanning and reconstruction image performance testing, in particular to axial performance testing of CT spiral scanning and reconstruction images, and specifically to an axial performance testing phantom of CT spiral scanning and multi-plane reconstruction images. Background Art

[0002] At present, the medical CT scanning systems equipped in my country's medical institutions have completed the update from single-row axial scanning CT to multi-row spiral scanning CT.

[0003] When CT scans are performed in clinical diagnostic examinations, spiral scanning is used for cardiac and cerebrovascular angiography and chest and abdominal disease examinations (that is, the subject lying flat on the examination bed moves with the bed when the X-rays are rotated, commonly known as "spiral scanning"). It has the advantages of fast scanning and imaging speeds, but its disadvantage is that the image quality is not as good as that of the so-called "axial scanning" in which the examination bed does not move during scanning.

[0004] During CT scanning, in order to accurately determine the morphology of the lesion and avoid misdiagnosis or missed diagnosis, medical staff often use spiral scanning technology to perform multi-axial plane reconstruction after scanning and reconstructing the Z-axis tomographic XY plane image (cross-sectional image), to obtain sagittal images (the ZY plane perpendicular to the ground along the anterior-posterior diameter of the human body lying flat, i.e. the Z axis, is the sagittal plane) and coronal images (the XZ plane parallel to the ground along the left-right diameter of the human body, i.e. the X axis, is the coronal plane), or three-dimensional reconstruction at any angle.

[0005] There is no quality management standard for the performance of spiral scanning 3D reconstruction images. CT manufacturers claim that they are isotropic, but there are no detailed technical indicators and certification documents. When hospitals conduct clinical radiological diagnosis, they use their CT system to axially scan existing detection phantoms to reconstruct XY plane image performance parameters to estimate the morphology and resolution of lesion 3D images. This is a technical rigor defect, especially for wide beam multi-row spiral CT scanning systems. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a CT spiral scanning multi-plane reconstruction image axial performance test phantom, the phantom has a reasonable design, a simple structure, is firm and reliable, is easy to use and maintain. The phantom can be used for CT spiral scanning multi-plane reconstruction image axial performance test, provides measured data for the performance evaluation of reconstructing lesion three-dimensional images, and can also be used for measuring the performance of CT axial scanning reconstruction images.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A CT spiral scanning multi-planar reconstruction image axial performance test phantom, characterized by comprising:

[0009] The main body is a plexiglass cube or cuboid with a top, bottom, left, right, front and back.

[0010] The material of the body can also be other organic lightweight solid materials, such as polycarbonate PC, polystyrene PS, nylon or bakelite.

[0011] A tungsten wire is arranged in the body along the Z-axis direction for measuring the "spatial resolution" of CT spiral scanning multi-planar reconstruction images, that is, high contrast resolution. The diameter of the tungsten wire is 0.05-0.15mm. A string of tungsten beads is arranged along the X-axis and Y-axis directions for measuring the "spatial resolution" of CT spiral scanning multi-planar reconstruction images, that is, high contrast resolution. The tungsten bead string includes a plurality of tungsten beads. The diameter of the tungsten beads is 0.2-0.3mm, and the bead spacing is 5mm. The three tungsten wires and tungsten bead strings do not overlap or cross each other on the same plane.

[0012] The advantages of this design are: the data used for the three-dimensional reconstruction of the spiral scanning image is obtained from the continuous scanning acquisition when the examination bed (Z-axis direction) moves. The performance of the point-shaped images of the tungsten wire segment and the tungsten bead on the XY plane transverse to the Z axis is almost indistinguishable. The difference in the spatial resolution MTF value measured by two point-shaped images on the same plane is less than 0.5Lp / cm (measured in the range of 5-16Lp / cm), and the two values ​​are equal or one is higher and the other is lower. In the reconstructed YZ plane transverse to the X-axis and the XZ plane transverse to the Y axis, the hardening artifact of the tungsten wire in a single direction is obvious, and the tungsten bead is isotropic in the three-dimensional scanning and is not affected by the hardening artifact. The MTF value measured by the bead point image in the same XZ or YZ plane can be higher than 1.0Lp / cm than the MTF value calculated by the tungsten wire segment point image. Therefore, this scheme sets the tungsten wire in the Z-axis direction and sets the tungsten bead string in the X and Y axis directions (bead spacing 5mm). The MTF value of the spatial resolution of each image with various scanning layer thicknesses can be continuously measured in the Z-axis direction and within the tungsten wire length range, but it cannot be measured in the X-axis or Y-axis direction, that is, only the spatial resolution of the bead image image can be measured.

[0013] The six surfaces of the body are each provided with 1 to 5 tungsten wires with a diameter of 0.1 to 0.3 mm for measuring the layer thickness deviation of CT spiral scanning multi-planar reconstruction images. The tungsten wires are all obliquely arranged on the surface, with the left side lower and the right side higher or the left side higher and the right side lower, equidistantly and in parallel. The highest end of the tungsten wire located at the bottom and the lowest end of the adjacent tungsten wire located at the top are on the same horizontal line. The angle between the oblique lines on the top and bottom for measuring the scanning layer thickness deviation across the Z axis and the front or back of the body is α1, the angle between the oblique lines on the front and back for measuring the scanning layer thickness deviation across the X axis and the left or right side of the body is α2, and the angle between the oblique lines on the left and right sides for measuring the scanning layer thickness deviation across the Y axis and the top or bottom of the body is α3. The angles α1, α2, and α3 are 18.4° to 45°.

[0014] The tungsten wire on the surface of the body can also be made of copper wire, steel wire or tin wire;

[0015] Furthermore, the tungsten wires on the six surfaces of the organic glass body are arranged in grooves on the surface of the body, three tungsten wires are arranged on the top and bottom, two tungsten wires are arranged on the left, right, front and back, the diameter of the tungsten wire is selected to be 0.1 mm, all the tungsten wires are arranged symmetrically with the center of the surface, and the angles α1, α2 and α3 are all 26.6°;

[0016] Further,

[0017] The main body has a first through hole formed along the X-axis direction.

[0018] The body has a second through hole formed along the Y axis.

[0019] The main body has a third through hole formed along the Z axis.

[0020] The tungsten wire and tungsten bead string used to measure the "spatial resolution" of the image are respectively arranged at the central axis position of the cylindrical support protection rod adapted to the above-mentioned through hole;

[0021] Furthermore, the main body is a cuboid, the long side of which is along the Z-axis direction, and the four sides of the main body along the Z-axis direction are provided with plane or arc chamfers;

[0022] The test phantom provided by the present invention has the advantages of reasonable design, simple structure, firmness and reliability, easy use and maintenance, etc. It has high test efficiency and can meet the requirements of axial performance testing of CT spiral scanning multi-plane reconstruction images, and can also be used for measuring the performance of CT axial scanning reconstruction images.

[0023] The test phantom of the present invention has high testing efficiency. With the data of a single spiral scan of the test phantom, all commercially available spiral CT scanning systems can reconstruct three plane images of XY, XZ and YZ. The relevant software is compiled using existing image processing technology to measure the layer thickness deviation (mm) and spatial resolution MTF (Lp / mm) of the reconstructed image.

[0024] The software measures the layer thickness deviation (mm) of the reconstructed image, that is, analyzes the "half-width" length of the metal wire image corresponding to the three plane images XY, XZ and YZ obtained by computing the tomography test model reconstruction, and calculates the precise value of the scanning reconstruction layer thickness.

[0025] The software measures the image spatial resolution MTF (Lp / mm), that is, the software analyzes the point image of a triaxially arranged tungsten wire (for example, 0.05mm diameter, total length 50-200mm) or tungsten bead obtained by computing the tomography test model reconstruction plane, analyzes its two-dimensional line spread function based on the point spread function of the prior art, calculates and gives a modulation transfer function curve (MTF), and marks the contrast on the curve and the corresponding spatial resolution value, line pairs / centimeter (Lp / cm).

[0026] If a known water phantom is connected in front of or behind the test phantom described in the present invention and relevant software is compiled using existing image processing technology, the following properties of the spiral scanning water phantom reconstructed multi-plane image can be measured: CT value of water, image noise, uniformity and low contrast detectability (LCD). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention has the following accompanying drawings:

[0028] Figure 1 Schematic diagram of the test phantom.

[0029] Figure 2 Schematic diagram of the test model.

[0030] Figure 3 The schematic diagram below the test model is as follows:

[0031] Figure 4 Schematic diagram of the left and right sides of the test phantom.

[0032] Figure 5 Schematic diagram of the front of the test phantom.

[0033] Figure 6 Schematic diagram of the back of the test phantom.

[0034] Figures 7 to 11 Schematic diagram of the specific number of metal wires.

[0035] Fig.12 Schematic diagram of the layout of three tungsten wires and tungsten beads DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0037] See attached Figure 1-12 , Figure 1 is a three-dimensional schematic diagram of the present invention, facing the rear 6 of the mold body, Figure 2 to Figure 6 It is a schematic diagram of the six-sided development of the present invention, which is developed based on the front 5 of the model body.

[0038] The present invention is a phantom for testing the axial performance of CT spiral scanning multi-plane reconstruction images, comprising:

[0039] The body 20 is a cube or a rectangular parallelepiped having three pairs of surfaces: an upper surface 1, a lower surface 2, a left surface 3, a right surface 4, a front surface 5, and a rear surface 6 (see Figure 1 ), the material of the main body 20 is selected from organic lightweight solid materials, preferably organic materials with a density close to that of water, such as polycarbonate PC, high-density polyethylene, polystyrene PS, plexiglass (PMMA, also known as acrylic), nylon or bakelite, etc. In this embodiment, plexiglass is selected.

[0040] Tungsten wires and tungsten beads are arranged in the body along the X, Y, and Z axis directions for measuring the "spatial resolution" of CT spiral scanning multi-planar reconstruction images, i.e., high contrast resolution. Specifically, the following implementation scheme can be adopted (see Fig.12 ): A tungsten wire 10 is arranged along the Z axis direction, and a string of tungsten beads is arranged along the X and Y axis directions respectively. The X axis is the first tungsten bead string 13, and the Y axis is the second tungsten bead string 14. The bead spacing is 5mm. The three tungsten wires and tungsten bead strings (referring to the tungsten wire 10, the first tungsten bead string 13, and the second tungsten bead string 14, a total of three) do not overlap or cross each other on the same plane. The diameter of the tungsten wire is 0.05-0.15mm, and the diameter of the tungsten beads is 0.2-0.3mm. The three tungsten wires and tungsten bead strings do not overlap or contact each other, which means that there are no intersecting and crossing contact points between the tungsten wire 10 and the two tungsten bead strings 13 and 14 in space; when setting the support rod (support protection rod), non-overlapping means that there are no intersecting and crossing contact points between the three protective tungsten wires and the support rods of the tungsten bead strings in space, in order to avoid overlapping of the scanned images; Fig.12 An embodiment of a tungsten wire and tungsten bead string layout is given. Figure 1 Supporting and protecting rods for fixing tungsten wires and tungsten beads are inserted into the middle holes 7, 8 and 9. The diameter of the tungsten wire is 0.05-0.15 mm, among which 0.05 mm, 0.07 mm, 0.1 mm, 0.12 mm and 0.15 mm are all selectable diameters.

[0041] The tungsten wire 10 and the tungsten beads 13 and 14 in the body 20 are respectively perpendicular to the three pairs of surfaces of the mold body. Fig.12As shown, the tungsten wire 10 in the Z-axis direction is perpendicular to the front (the patient's supine head position - i.e., the CT gantry position) and the back (the patient's foot position), the tungsten bead string 14 in the Y-axis direction is perpendicular to the top and bottom, and the tungsten bead string 13 in the X-axis direction is perpendicular to the left and right. The spatial arrangement of the tungsten wire and the tungsten bead string takes into account the uniformity of the reconstructed image and avoids the interference of X-ray scanning hardening artifacts.

[0042] The six surfaces of the body 20 are provided with 1 to 5 metal wires 30 for measuring the deviation of the layer thickness of the CT spiral scanning reconstructed image. The metal wires can be tungsten wires, copper wires, steel wires or tin wires. The number of metal wires on each surface can be the same, for example, 2, 3, 4 or 5. The number of metal wires on each surface can also be different. The material of the metal wires can be the same or different. The design and selection can be based on the length of the phantom and the ratio between the length of the metal wire image and the thickness of the scanning layer. For details, please refer to Figures 7 to 11 .exist Figure 2 to Figure 6 (Schematic diagram of the six surfaces of the mold body) In the given embodiment, two metal wires are provided on the front, back, left and right surfaces, and three metal wires are provided on the upper and lower surfaces respectively; the metal wires in this embodiment are tungsten wires.

[0043] The metal wires 30 are all disposed obliquely on the surface, parallel to each other and arranged at equal distances.

[0044] One embodiment of the present invention is: three metal wires are arranged on the upper 1 and lower 2 plane views for collecting layer thickness information of cross-sectional (XY plane) scanning and reconstruction images (either spiral scanning or axial scanning). The metal wire 30 can be arranged obliquely so that the left side is low and the right side is high, or so that the left side is high and the right side is low. The highest end 31 of the metal wire located at the bottom and the lowest end 32 of the adjacent metal wire located at the top are on the same horizontal line. The purpose of such arrangement is: within the length of the model, continuous layer thickness information can be collected on each layer of the image reconstructed by wide-range spiral scanning (or axial scanning), that is, the projection of the metal wire 30 will not be interrupted or overlapped during multi-layer continuous scanning and reconstruction.

[0045] In the left 3 and right 4 plane views, two metal wires are set to collect the layer thickness information of the coronal plane (XZ plane) scanning and reconstruction image.

[0046] In the anterior 5 and posterior 6 plane views, two metal wires are set to collect the layer thickness information of the sagittal plane (YZ plane) scan and reconstruction image.

[0047] The metal wires 30 provided on the six surfaces of the main body 20 are preferably tungsten wires. The tungsten wires can be attached to the surface of the mold or can be provided under the surface layer of the mold by other methods. Figures 1 to 6In the embodiment, the metal wire (tungsten wire) 30 is arranged in the groove 301 on the surface of the body 20, and three tungsten wires are arranged on the upper side 1 and the lower side 2, and two tungsten wires are arranged on the left side 3, the right side 4, the front side 5, and the back side 6. Due to the "partial volume effect" of CT scanning imaging, also known as the "volumetric effect", the "image contrast" of the image reconstructed by scanning different layer thicknesses with metal wires of the same material and wire diameter in the same background material can vary greatly. The tungsten wire diameter of 0.1 to 0.3 mm is the preferred value after experiments with various materials and wire diameters, among which 0.1 mm, 0.2 mm, and 0.3 mm are all diameters that can be selected.

[0048] The parallel metal wires (tungsten wires) can be offset on the surface of the phantom (i.e., set close to one side), but the better solution is: all tungsten wires are set symmetrically with the center of the surface, so that the tungsten wires are evenly distributed, and the test positioning and data processing programming are more convenient. For details, see Figures 1 to 6 .

[0049] The angle between the oblique lines on the upper surface 1 and the lower surface 2 for measuring the transverse plane (transverse Z axis) scanning layer thickness deviation and the front surface 5 or the rear surface 6 of the body 20 is α1, the angle between the oblique lines on the front surface 5 and the rear surface 6 for measuring the sagittal plane (transverse X axis) scanning layer thickness deviation and the left surface 3 or the right surface 4 of the body 20 is α2, and the angle between the oblique lines on the left surface 3 and the right surface 4 for measuring the coronal plane (transverse Y axis) scanning layer thickness deviation and the upper surface 1 or the lower surface 2 of the body 20 is α3, and the angles α1, α2, and α3 are 18.4° to 45°, and the angles α1, α2, and α3 can be different or the same. When the angle is 45°, the length of the wire scanning reconstruction image is equal to the scanning reconstruction layer thickness. When the angle is 18.4°, the length of the wire scanning reconstruction image is three times the scanning reconstruction layer thickness (the projection relationship is: 1 / tanα), which can improve the measurement accuracy of thin layers, but also increase the difficulty of phantom placement. The optimal selection of the angles α1, α2, and α3 is 26.6°, and the "half-height width" length of the wire scanning reconstruction image is twice the scanning reconstruction layer thickness. In this way, a series of products can be formed.

[0050] The tungsten wire and tungsten bead string mentioned in the present invention can be directly set in the mold body, for example, it is made into one piece when the mold body is formed. In order to facilitate the processing and manufacturing of the mold body and also to facilitate the testing and use of the mold body, the main body 20 mentioned in the present invention has a through hole 7, 8, 9 along the three axes of X, Y, and Z. The tungsten wire and tungsten bead string are set in the inner axis position of a cylindrical support protection rod made of the same material as the mold body (not shown in the figure), and the size of the support protection rod is matched with the size of the through hole. In this way, the manufacturing accuracy is guaranteed, and the assembly and use are convenient.

[0051] The main body 20 can be a cube or a cuboid (including 6 rectangular faces, or 2 square faces at the front and back, and 4 rectangular faces at the top, bottom, left and right). Specifically, different shapes and sizes can be selected according to different needs to design an independent phantom or be combined with other CT imaging performance test modules to form a multifunctional test phantom.

[0052] As an optional embodiment, the side length of the phantom can be 7 to 24 cm. For example, cubic phantoms such as 7*7*7, 9*9*9, 11*11*11, 12*12*12, 15*15*15, 17*17*17, 20*20*20, 22*22*22 or 24*24*24 cm are all optional embodiments; for a rectangular phantom, its Z-axial length can be 1.1, 1.3, 1.5, 1.7 or 2.0 times the length of the front and back sides respectively. Such a rectangular test phantom can be used in a head phantom or an abdomen phantom; a cubic test phantom with a side length of 20, 22 or 24 cm can be used independently.

[0053] The specific configuration of the metal wire 30 is shown in Figures 7 to 11 , the dotted line in the figure is only used to indicate that "the highest end 31 of the metal wire 30 located below and the lowest end 32 of the adjacent metal wire 30 located above are on the same horizontal line."

[0054] Figure 7 The figure shows a metal wire 30 with an angle α 1、2、3 The angle is 45°, which can be used for scanning test with a layer thickness of 10 mm;

[0055] Figure 8 The figure shows two metal wires 30, with an angle α 1、2、3 is 26.56° (approximately 26.6°);

[0056] Fig. 9 The figure shows three metal wires 30, with an angle α 1、2、3 It is 18.4°, which can be used for scanning tests with a layer thickness of 5 mm.

[0057] The main body 20 mentioned in the present invention can be a cube or a rectangular parallelepiped, and the long side of the rectangular parallelepiped is along the Z-axis direction.

[0058] In order to be used in conjunction with other test phantoms, the four edges of the main body 20 along the Z-axis direction of the present invention may be provided with plane chamfers or arc surface chamfers.

[0059] The test model described in the present invention, its test usage method and data processing method can all be carried out with reference to the existing technology and will not be described in detail.

[0060] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0061] Attachment:

[0062] Brief Instructions for Using the "CT Spiral Scanning Multi-planar Reconstruction Image Axial Performance Test Phantom"

[0063] The test phantom can be designed into an independent phantom in different shapes and sizes according to different needs, or combined with other CT imaging performance test modules to form a multifunctional test phantom.

[0064] When testing the axial performance index of CT spiral scanning and reconstruction images, place the phantom on the scanning bed near the gantry end, with the phantom Z axis parallel to the scanning center axis. Adjust the bed height, and adjust the center of the phantom to the system scanning center axis under the guidance of the positioning light. Scan one front and one side positioning image. On the system image display interface, check and calibrate the placement of the phantom correctly, that is, the top and bottom are horizontal, the left and right sides are vertical, and the front and back sides are vertical.

[0065] Develop a spiral scanning acquisition plan: set standard kV, mA, scanning time per circle, scanning range (length), pitch, layer thickness (it is best to choose the thinnest layer thickness for spiral acquisition) and reconstruction algorithm, etc. Design the reconstruction layer thickness, click the system axial reconstruction program, the system automatically reconstructs the Z, Y, and X three-axis plane images, sends the reconstructed images to the image workstation, and copies the DICOM image data using the optical drive.

[0066] The software compiled using existing image processing technology can measure the layer thickness deviation (mm) and spatial resolution MTF (Lp / mm) of the reconstructed image. The layer thickness deviation can also be measured with the naked eye using the DICOM inspection software "RadiAnt DICOM Viewer (64-bit) Medixant".

Claims

1. A CT spiral scanning multi-planar reconstruction image axial performance test phantom, characterized in that: include: The body (20) is a rectangular parallelepiped having a top (1), a bottom (2), a left side (3), a right side (4), a front side (5), and a back side (6). The body (20) is made of an organic light solid material, including polycarbonate PC, polystyrene PS, organic glass, nylon or bakelite. Tungsten beads (13, 14) and tungsten wires (10) for measuring the spatial resolution, i.e., high contrast resolution, of CT spiral scanning reconstructed images are arranged in the body (20) along the three axes of X, Y, and Z, wherein a string of tungsten beads (13, 14) is arranged along the X and Y axes respectively, the diameter of the tungsten beads is 0.2-0.3 mm, and the distance between the beads is 5 mm, and a tungsten wire (10) is arranged along the Z axis, the diameter of the tungsten wire is 0.05-0.15 mm, and the three tungsten wires and tungsten beads arranged in the three axes are on the same plane and do not overlap or cross each other; The six surfaces of the body (20) are each provided with 2 to 5 metal wires (30) for measuring the layer thickness deviation of the CT spiral scanning reconstructed image. The metal wires (30) are all arranged obliquely on the surface, with the left side lower and the right side higher or the left side higher and the right side lower, equidistantly and in parallel. The highest end (31) of the metal wire located at the bottom and the lowest end (32) of the metal wire located at the top adjacent thereto are located on the same horizontal line. The oblique lines on the top (1) and the bottom (2) for measuring the layer thickness deviation of the scanning transverse to the Z axis are aligned with the front (5) or the back (6) of the body (20). The angle between the front (5) and rear (6) oblique lines for measuring the scanning layer thickness deviation across the X-axis and the left (3) or right (4) of the main body (20) is α2, and the angle between the left (3) and right (4) oblique lines for measuring the scanning layer thickness deviation across the Y-axis and the top (1) or bottom (2) of the main body (20) is α3, the angles α1, α2, and α3 are 18.4° to 45°, the diameter of the metal wire is 0.1 to 0.3 mm, and the metal wire is tungsten wire, copper wire, steel wire, or tin wire.

2. The CT spiral scanning multi-planar reconstruction image axial performance test phantom according to claim 1, characterized in that: The body (20) is an organic glass body, and the metal wires (30) provided on the six surfaces thereof are tungsten wires. The metal wires (30) are arranged in grooves (301) on the surface of the body (20), and three tungsten wires are respectively provided on the top (1) and the bottom (2), and two tungsten wires are respectively provided on the left (3), the right (4), the front (5), and the back (6). The diameter of the tungsten wire is selected to be 0.1 mm, and all the tungsten wires are symmetrically arranged with respect to the center of the surface on which they are located, and the angles α1, α2, and α3 are all 26.6°.

3. The CT spiral scanning multi-planar reconstruction image axial performance test phantom according to claim 1 or 2, characterized in that: The body (20) is provided with a first through hole (7) along the X-axis direction. The body (20) is provided with a second through hole (8) along the Y-axis direction. The body (20) is provided with a third through hole (9) along the Z-axis direction. The tungsten beads (13, 14) and the tungsten wire (10) are respectively arranged at the center of a supporting protection rod matched with the first to third through holes (7, 8, 9).

4. The CT spiral scanning multi-planar reconstruction image axial performance test phantom according to claim 1 or 2, characterized in that: The main body (20) is a rectangular parallelepiped, with its long side along the Z-axis direction; the four sides of the main body (20) along the Z-axis direction are provided with plane or arc chamfers.

5. The CT spiral scanning multi-planar reconstruction image axial performance test phantom according to claim 3, characterized in that: The main body (20) is a rectangular parallelepiped, with its long side along the Z-axis direction; the four sides of the main body (20) along the Z-axis direction are provided with plane or arc chamfers.

Images