Radiation shielding agent for CT examination

Abstract

The present invention relates to a radiation shielding agent for CT examination, wherein the shielding agent exhibits excellent uniformity while reducing the occurrence of artifacts compared to conventional shielding agents. The present invention is to provide a shielding agent for CT imaging, which comprises: a gadolinium layer being 2 to 8 mm in thickness and containing 100 to 150 cc of 0.25 to 1 mmol gadobutrol; an aluminum layer having a thickness of 1 to 5 mm; and a polyurethane layer having a thickness of 5 to 15 mm.

Description

Radiation shielding for CT scans

[0001] The present invention relates to a radiation shielding agent for CT examination.

[0002]

[0003] X-ray imaging equipment detects radiation passing through a subject with a radiation detector to visualize the interior of the subject, i.e. the body's anatomical structures or structures. It is used in hospitals for the diagnosis and treatment of patients, and in various industrial settings for non-destructive testing of various structures. The radiation used in these equipment is a type of invisible light with energy, including alpha rays, beta rays, gamma rays, X-rays, and electromagnetic waves emitted when radioactive elements decay. It has strong penetrability into living organisms. The use of radiation, which began with Röntgen's discovery in 1895, has been useful in various fields for a long time, and has contributed greatly to the diagnosis and treatment of patients, especially in the medical field. Recently, with the advancement of cutting-edge technology, digital X-ray imaging equipment combined with digital technology has been developed, and this has contributed greatly to more accurate and rapid diagnosis and effective treatment of diseases than before.

[0004] However, invisible radiation emitted from radiation generators (i.e., radiation sources) can have harmful effects on the human body. Even small doses of radiation can cause genetic or cellular mutations and lead to various cancers. Furthermore, genetic mutations are passed down from generation to generation, making it crucial to avoid excessive or unnecessary radiation exposure. Therefore, radiation exposure is often limited to only certain parts of a patient's body requiring X-rays, or radiation shielding is used to protect the remaining areas.

[0005] Meanwhile, despite the use of these radiation shielding agents, there have been problems such as artifacts occurring on the patient surface where the shielding agent is placed, or uniformity deteriorating the image quality.

[0006] To solve these problems, the inventors of the present invention invented a radiation shielding agent for CT that has excellent uniformity while reducing the occurrence of artifacts by laminating gadobutrol, aluminum, and polyurethane having shielding properties.

[0007]

[0008] One aspect of the present invention is to provide a shielding agent for CT imaging comprising a gadolinium layer having a thickness of 2 to 8 mm containing 100 to 150 cc of gadobutrol having a thickness of 0.25 to 1 mmol; an aluminum layer having a thickness of 1 to 5 mm; and a polyurethane layer having a thickness of 5 to 15 mm.

[0009]

[0010] One aspect of the present invention provides a shielding agent for CT imaging comprising a gadolinium layer having a thickness of 2 to 8 mm containing 100 to 150 cc of gadobutrol having a thickness of 0.25 to 1 mmol; an aluminum layer having a thickness of 1 to 5 mm; and a polyurethane layer having a thickness of 5 to 15 mm.

[0011] As an example of the present invention, the gadolinium layer may contain 110 to 140 cc of gadobutrol at 0.4 to 0.7 mmol.

[0012] As an example of the present invention, the gadolinium layer may have a thickness of 3 to 6 mm; the aluminum layer may have a thickness of 2 to 4 mm; and the polyurethane layer may have a thickness of 6 to 13 mm.

[0013] As an example of the present invention, the shielding agent may have a radiation shielding power of 40 to 60%.

[0014] As an example of the present invention, the shielding agent may be used for shielding the gonads in abdominal CT, shielding the eyes in ORBIT CT, and any one of PET CT.

[0015]

[0016] The radiation shielding agent for CT examination of the present invention has excellent uniformity while reducing the occurrence of artifacts compared to conventional shielding agents.

[0017]

[0018] Fig. 1 is a diagram showing the laminated structure of the shielding agent of the present invention.

[0019] Figure 2 is a photograph showing the actual appearance of the shielding agent of the present invention.

[0020] Figure 3 is a photograph showing the results of Example 3.

[0021]

[0022] One aspect of the present invention provides a shielding material (100) for CT imaging comprising a gadolinium layer (110) having a thickness of 2 to 8 mm containing 100 to 150 cc of gadobutrol of 0.25 to 1 mmol; an aluminum layer (120) having a thickness of 1 to 5 mm; and a polyurethane layer (130) having a thickness of 5 to 15 mm.

[0023] The above-mentioned gadolinium layer (110) is a layer containing gadobutrol, and the above-mentioned gadobutrol can form a gadolinium layer in a known manner. In one specific example, the gadobutrol can be manufactured by placing it in a container made of a known resin, or by adsorbing gadobutrol in the above range onto a known resin. In one example of the present invention, the gadobutrol solution can be manufactured by placing it in a polyethylene material container having a size of 200 (W) x 150 (D).

[0024] The above gadobutrol is a type of MRI contrast agent containing gadolinium and having an asymmetric macrocycle, and is sold under the trade names Gadovist or Gadavist. It is sold under the trade names Gadovist or Gadavist. The contrast action of gadobutrol consists of a nonionic complex composed of a gadolinium cation and a macrocyclic ligand, 2,2,2-((10-1,3,4-trihydroxybutan-2-yl)-1,4,7,10-tetraazacyclodotehcan-1,4,7-triyl)triacetic acid (hereinafter referred to as butrol).

[0025] The above gadolinium layer (110) may contain 100 to 150 cc of gadobutrol of 0.25 to 1 mmol, in one specific example, 110 to 140 cc of gadobutrol of 0.4 to 0.7 mmol, and in one example, 120 cc of gadobutrol of 0.5 mmol. As an example, the original solution of Gadovist (gadobutrol) (100%) may be diluted (50%) in sterile distilled water and placed in a polyethylene container measuring 200 (W) x 150 (D). If the concentration and / or content of gadobutrol outside the above range is included, the desired effect of the present invention cannot be obtained.

[0026] The above gadolinium layer (110) may have a thickness of 2 to 8 mm, more specifically 3 to 6 mm, and as an example, the gadolinium layer may have a thickness of 5 mm. If the gadolinium layer is formed with a thickness outside the above range, the desired effect of the present invention cannot be obtained. In this case, if the gadolinium layer is manufactured by adsorbing gadobutrol onto a resin, the thickness of the adsorbed gadobutrol can be controlled to form the thickness of the gadolinium layer, and if the gadobutrol is manufactured by containing it in a container made of a known resin, the thickness of the gadolinium layer can be controlled to form the thickness of the container.

[0027] The radiation emitted during a CT scan is multi-energy, and materials with high atomic numbers and high density are primarily used for radiation shielding. Therefore, a layer of high-atomic number gadolinium acts as a primary filter, while the scattered radiation generated is secondarily absorbed by an aluminum layer, acting as an additional filter. The further weakened strands are triple-absorbed by the polyurethane layer, allowing a homogenized beam of radiation to be delivered to the subject.

[0028] Since the structure generally used for radiation shielding limits the examination area, there is no shielding other than the existing bismuth, and bismuth also generates artifacts and affects the image, so it is only used for chest CT examinations. However, materials with low atomic numbers have low radiation shielding rates, but the effect of artifacts is small, so a shielding material that forms a multi-layer structure composed in order of atomic number from high to low is used, so that scattered rays and low-energy radiation generated as they pass through each layer are removed, and the beam is homogenized to provide a better image.

[0029] The above aluminum layer (120) is formed to a thickness of 1 to 5 mm and is a layer capable of shielding scattered rays from radiation, and can be manufactured and formed by a known method. More specifically, the thickness of the aluminum layer may be 2 to 4 mm, for example, 3 mm. If the aluminum layer is formed outside the above thickness range, the shielding efficiency of beta rays may be somewhat reduced, or it may be difficult to achieve a lightweight shielding agent, and thus the desired effects of the present invention may not be obtained.

[0030] The above polyurethane layer (130) is formed to a thickness of 5 to 15 mm, and can improve the usability of the sealant of the present invention. Specifically, the polyurethane layer may have a thickness of 6 to 13 mm, or, for example, 10 mm.

[0031] In one specific example of the present invention, the shielding agent may have a radiation shielding power of 40 to 60%, more specifically, 45 to 55%, and as an example, 50%. The present invention is composed of the above-described gadolinium layer (110), aluminum layer (120), and polyurethane layer (130), and thus has excellent radiation shielding power and can achieve a level similar to that of conventional radiation shielding agents.

[0032] The above shielding agent can be used in various fields requiring radiation shielding, and specifically, can be used in medical settings, and as a specific example of the present invention, can be used for shielding the gonads in abdominal CT, shielding the eyes in ORBIT CT, and any one of PET CT.

[0033]

[0034] Hereinafter, one or more specific examples will be described in more detail through examples. However, these examples are intended to exemplify one or more specific examples, and the scope of the present invention is not limited to these examples.

[0035]

[0036] Manufacturing Example 1: Manufacturing of the shielding agent of the present invention

[0037] The shielding agent of the present invention and comparative examples were produced.

[0038] Gadovist (Bayer AG, Germany) and aluminum, polyurethane (SSW25, density - 25 kg / m) 3 ) is composed of three layers in the order of . For the gadovist layer, the capacity is 120 cc, the size is 200 (W) x 150 (D) x 5 (H) mm, and 100% original solution and 75%, 50%, and 25% diluted with sterilized distilled water are used. For the aluminum layer, the size is 430 x 200 x 5 mm, 430 x 200 x 3 mm, and the polyurethane layer is a single configuration with the size of 430 x 200 x 100 mm.

[0039] As a result, a shielding agent was produced as shown in Fig. 2.

[0040] As comparative examples, aluminum alone (AL 3 mm), gadolinium alone (GD 100% 5 mm, GD 75% 5 mm, GD 50% 5 mm, GD 25% 5 mm), aluminum + gadolinium composite (AL3 mm + GD 100%, AL3 mm + GD 75%, AL3 mm + GD 25%), and a control group, a conventional shielding body bismuth-coated latex (F&L Medical Products Co. 0.060 mmPb equivalent, USA) measuring 430 x 200 x 1 mm were used.

[0041]

[0042] Example 1: Confirmation of radiation shielding power

[0043] The radiation shielding power of the shielding agent of the present invention and the control shielding agent was compared and confirmed.

[0044] Specifically, the CT equipment used was GE's Revolution Apex (General Electric Health Care, UK), and the subjects were RSD Pelvis Phantoms (SPL-164, Radiology Support Devices Inc, USA) and ACR Phantom (Model #438, Gammex TMI, USA). For dose measurement and image quality evaluation, a fluorescent glass dosimeter (GD-352M, 12 mm, FGD-1000 reader, Asahi Techno Glass Co, Shizuoka, Japan) and the ACR phantom Accreditation Program were used.

[0045] Dosimetry was performed by attaching a glass dosimeter to the surface of RSD Pelvis Phantoms and placing a shield composed of 3 mm aluminum, 100 mm polyurethane, and 100%, 75%, 50%, and 25% Gadobis, and a shield composed of 5 mm aluminum, 100 mm polyurethane, 100%, 75%, 50%, and 25% Gadobis, and bismuth on top of them to measure the dose. For image quality evaluation, the same shield was placed on the top center of the ACR Phantom and the experiment was conducted. The inspection conditions were 120 kVp, 150 mAs, Noise Index 14.4, thickness 2.5 mm, and algorithm set to STD and performed with axial scan type.

[0046] As a result, as confirmed in Table 1, some aluminum+gadolinium complexes showed high shielding power levels (AL3mm+ GD 100%, AL3mm+ GD 75%) and high synergy levels (AL3mm+ GD 25%), but it was confirmed that the shielding agent of the present invention showed high shielding power and synergy levels.

[0047] The value of AL and GD corresponding to the composition shielding force is added together. Synergy level AL 3mm 15.52% GD 100% 5mm 43.24% GD 75% 5mm 36.41% GD 50% 5mm 28.69% GD 25% 5mm 21.50% AL 3mm + GD 100% 54.55% 58.76% -4.21% AL 3mm + GD 75% 53.06% 51.93% 1.13% The present invention (AL 3mm + GD 50%) 50.43% 44.21% 6.22% AL 3mm + GD 25% 43.59% 37.02% 6.57% Bismuth 48.52%

[0048]

[0049] Example 2: Uniformity Verification

[0050] The uniformity of the shielding agent of the present invention and the control shielding agent was compared and confirmed.

[0051] Specifically, the experimental results of Example 1 were converted, and as a result, as confirmed in Table 2, it can be seen that the shielding agent of the present invention has uniform values ​​in the upper, lower, left, right, and central portions.

[0052] Composition Top Bottom Left Right Center RR (100 mm) Non-shield 0.5 7 1.1 7 0.9 10.5 5 0.0 2 9 9.93 mm Bismuth 5 0.6 5 5.2 1 1 1.0 4 7.3 18.6 9 7.65 mm AL3 mm + GD 100% 35.9 13.6 5 3 5 4.8 6 4.8 1 9 8.08 mm AL3 mm + GD 75% 27.7 7 3.4 4.7 8 4.2 8 3.9 4 9 8.18 mm Invention (AL3 mm + GD 50%) 18.8 5 2.6 12.9 2.5 7 2.7 6 9 8.39 mm AL3 mm + GD 25% 8.9 2.1 9 1.8 2 1.5 8 1.0 9 8.73 mm

[0053]

[0054] Example 3: Checking image quality

[0055] The radiation shielding power of the shielding agent of the present invention and the control shielding agent was compared and confirmed.

[0056] Specifically, the shielding agent of the present invention manufactured in Manufacturing Example 1 and a comparative example were used. For dose measurement, a glass dosimeter was attached to the surface of the phantoms, and each shielding agent was placed on top of it to measure the dose. For image quality evaluation, the same shielding agent was placed on the upper center of the phantom, and uniformity, SNR, and CNR were measured.

[0057] [Calculation formula]

[0058] SNR = CT#t / SDb, CNR = (CT#t- CT#b) / SDb

[0059] (CT#t: attenuation coefficient value (CT number) of the region of interest (ROI blue circle), SDb is the noise (standard deviation) of the background region (ROI red circle) (CT#b is the attenuation coefficient value of the background region (ROI red circle)))

[0060]

[0061] As a result, as confirmed in Fig. 3, it can be seen that the shielding agent of the present invention has a lower noise value and less artifacts (a phenomenon in which the image is burned out) than when no shielding agent is used (NON).

[0062]

[0063] The present invention has been described above, focusing on preferred embodiments thereof. Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered illustrative rather than limiting. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

A 2 to 8 mm thick gadolinium layer containing 100 to 150 cc of 0.25 to 1 mmol of gadobutrol; an aluminum layer 1 to 5 mm thick; and A shielding material for CT imaging comprising a polyurethane layer having a thickness of 5 to 15 mm.

2. In paragraph 1, A shielding agent for CT scanning, wherein the gadolinium layer contains 110 to 140 cc of 0.4 to 0.7 mmol of gadobutrol.

3. In paragraph 1, The above gadolinium layer has a thickness of 3 to 6 mm; The above aluminum layer has a thickness of 2 to 4 mm; and The above polyurethane layer is a shielding material for CT scanning having a thickness of 6 to 13 mm.

4. In paragraph 1, The above shielding agent is a shielding agent for CT scanning having a radiation shielding power of 40 to 60%.

5. In paragraph 1, The above shielding agent is a CT imaging shielding agent used for shielding the gonads in abdominal CT, shielding the eyes in ORBIT CT, and any one of PET CT.

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