Radiation imaging tool, imaging device, method for imaging, and optical microscope

Abstract

To acquire an image on the dynamic state of a material in a living body, while keeping the physiological activity of the living body.SOLUTION: A radiation imaging tool includes: a container 10 for storing a test sample 91, in which a medium 92 containing a radioactive nuclide that the test sample 91 takes in is placed on a container inner side 10c of a bottom surface 10b and the bottom surface 10b transmits the radiation 93a discharged from the radioactive nuclide; a shielding body 21 arranged on the outer side of the container of the bottom surface 10b, for blocking light 99 radiated to the test sample 91 and transmitting the radiation 93a; and a scintillator 22 arranged on the opposite side of the shielding body 21 to the side where the container 10 is arranged, the scintillator discharging fluorescence 93b when irradiated with the radiation 93a.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for imaging radiation emitted by a radionuclide incorporated in a subject, an imaging device comprising said apparatus and an imaging method using said apparatus, and an optical microscope incorporating said apparatus. [Background technology]

[0002] Fertilizers are essential in modern agriculture. In recent years, the price of fertilizers such as phosphate rock has been rising sharply due to the depletion of mineral resources and the influence of the world situation. Since Japan relies on imports of chemical fertilizers from overseas, in order to practice sustainable agriculture, it is necessary to efficiently cultivate crops with small amounts of fertilizer by managing the amount of fertilizer used.

[0003] Examples of soil improvement items include diagnosing the condition of the soil and supplementing the soil with only the fertilizer elements that are lacking, and utilizing soil microorganisms that contribute to the absorption of inorganic elements. Examples of crop improvement items include clarifying the mechanism by which crops absorb fertilizer. For example, Patent Document 1 discloses a technology for acquiring images of the dynamics of substances within plants in real time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-111681 A Summary of the Invention [Problem to be solved by the invention]

[0005] If the mechanism by which agricultural crops absorb fertilizers, i.e., the mechanism by which plants absorb elements, could be elucidated in more detail, it is expected that the ability of agricultural crops to absorb fertilizers could be further improved. Agricultural crops are plants, and the physiological activity of living plants requires irradiation with light to perform photosynthesis. However, in the technology of Patent Document 1, the subject plant is shaded during image acquisition, and its physiological activity is reduced. In order to clarify the mechanism by which plants absorb elements in more detail, a technology is required that clarifies the dynamics of substances within the plant while maintaining the physiological activity of the plant.

[0006] An object of the present invention is to obtain images relating to the dynamics of substances in a living body while maintaining the physiological activity of the living body. [Means for solving the problem]

[0007] The present invention for solving the above problems includes, for example, the following aspects.

[0008] (Section 1) a container for accommodating a subject, the container having a bottom surface on an inner side of the container on which a medium containing a radionuclide to be taken in by the subject is placed, the bottom surface being transparent to radiation emitted from the radionuclide; a light shielding body disposed on the bottom surface on an outer side of the container, the light shielding body blocking light irradiated onto the subject and transmitting the radiation; a scintillator that is disposed on the opposite side of the light shielding body from the container and emits fluorescent light when irradiated with the radiation; A radiation imaging device comprising: (Section 2) Item 1, an imaging apparatus according to item 1, wherein the bottom surface is further transparent to light that is irradiated onto the subject. (Section 3) Item 1. The imaging device of item 1, wherein the light blocking body is integral with the container. (Section 4) 4. The imaging apparatus of any one of claims 1 to 3, wherein the light shield is carbon graphite having a thickness of 10 μm to 25 μm. (Section 5) 4. The imaging apparatus of any one of claims 1 to 3, wherein the light shield is aluminum having a thickness of 12 μm to 24 μm. (Section 6) An imaging device according to any one of claims 1 to 5, an imaging element for imaging the fluorescence emitted from the scintillator; A radiation imaging device comprising: (Section 7) Item 7. The imaging device according to item 6, further comprising an objective lens disposed between the scintillator and the imaging element, for focusing the fluorescence onto the imaging element. (Section 8) Item 8. An optical microscope incorporating the imaging device according to item 6 or 7. (Section 9) A step of housing a subject in a container, the step being to place a medium containing a radionuclide to be taken up by the subject on the inside of the container at the bottom, and to transmit radiation emitted from the radionuclide through the bottom; a step of placing a light shield on the outer side of the container of the bottom surface to block light irradiated to the subject and transmit the radiation; a step of disposing a scintillator on the opposite side of the light shielding body from the container, converting the transmitted radiation into fluorescent light and emitting the fluorescent light; capturing an image of the fluorescence emitted from the scintillator using an imaging element; A radiation imaging method comprising: (Section 10) a light-shielding body on which a subject is placed, the light-shielding body having a medium containing a radionuclide to be taken up by the subject placed on its surface, the light-shielding body blocking light irradiated onto the subject and transmitting radiation emitted from the radionuclide; a scintillator that is disposed on the opposite side of the light shielding body from the culture medium and emits fluorescence when irradiated with the radiation; an imaging element for imaging the fluorescence emitted from the scintillator; A radiation imaging device comprising: (Section 11) A step of placing a subject on a light-shielding body, the step being to place a medium containing a radionuclide to be taken up by the subject on the surface of the light-shielding body, thereby blocking light irradiated onto the subject and allowing radiation emitted from the radionuclide to pass through; a step of disposing a scintillator on the side of the light shielding body opposite to the medium, converting the transmitted radiation into fluorescence and emitting the fluorescence; capturing an image of the fluorescence emitted from the scintillator using an imaging element; A radiation imaging method comprising: Effect of the Invention

[0009] According to the present invention, images relating to the dynamics of substances in a living body can be obtained while maintaining the physiological activity of the living body. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a radiation imaging device according to an embodiment; [Diagram 2] 1 is a perspective view of a radiation imaging device according to an embodiment; [Diagram 3] FIG. 3 is an exploded perspective view of the imaging device shown in FIG. 2. [Figure 4] 3 is a cross-sectional view of the imaging device shown in FIG. 2 taken along line AA. [Diagram 5] FIG. 1 is a diagram showing a schematic configuration when a radiation imaging device according to an embodiment is incorporated into an optical microscope. [Figure 6] FIG. 6 is a diagram showing a schematic configuration of an optical microscope incorporating the radiation imaging device shown in FIG. 5. [Figure 7] FIG. 13 is a diagram showing a schematic configuration of a radiation imaging device according to another embodiment. [Figure 8] FIG. 13 is a diagram showing a schematic configuration of a radiation imaging device according to still another embodiment. [Figure 9] 1 shows the imaging results according to Example 1, which are examples of visualization of the phosphate absorption capacity of rice seedlings depending on differences in root morphology. [Figure 10]13 shows the imaging results according to Example 2, which are examples of visualization of the function of Arabidopsis thaliana roots absorbing phosphate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description and drawings, the same reference numerals denote the same or similar components, and therefore, redundant description of the same or similar components will be omitted.

[0012] [Imaging instruments and devices] Fig. 1 is a diagram showing a schematic configuration of a radiation imaging device according to an embodiment. Fig. 2 is a perspective view of a radiation imaging device according to an embodiment. Fig. 3 is an exploded perspective view of the imaging device shown in Fig. 2. Fig. 4 is a cross-sectional view taken along line AA of the imaging device shown in Fig. 2. Hereinafter, a radiation imaging device according to an embodiment will be described with reference to Figs. 1 to 4.

[0013] A radiation imaging device 100 according to one embodiment includes a container 10 that contains a subject 91, a light shielding body 21, a scintillator 22, and an image sensor 23. In this embodiment, of the components included in the imaging device 100, the container 10, the light shielding body 21, and the scintillator 22 excluding the image sensor 23 constitute a radiation imaging instrument, and the imaging device 100 includes the imaging instrument and the image sensor 23. The image sensor 23, together with the light shielding body 21 and the scintillator 22, constitutes a radiation imaging device 20.

[0014] The container 10 is a container for containing a subject 91, and a medium 92 containing a radionuclide to be taken in by the subject 91 is placed on the bottom surface 10b on the side of the container interior 10c. The bottom surface 10b transmits radiation 93a emitted from the radionuclide taken in by the subject 91. An opening 10a is provided on the upper surface of the container 10. The area of ​​the opening 10a is larger than the area of ​​the bottom surface 10b (in this embodiment, the area of ​​the surface 12a of the partition body 12 visible from the container interior 10c), and the area of ​​the bottom surface 10b is approximately the same as or larger than the area of ​​the imaging surface of the radiation imaging device 20. This ensures a field of view when the device 100 is incorporated into an optical microscope 200 to observe the subject 91, and makes it possible to image and observe the surroundings of the subject 91. Illustratively, the diameter of the opening 10a is about 50 mm, the diameter of the opening in the bottom surface 10b is about 25 mm, and the distance from the opening 10a to the bottom surface 10b (depth of the space inside the container 10c) is about 14 mm.

[0015] In this embodiment, the container 10 includes a laminated structure of an upper cylindrical body 11, a partition body 12, and a lower cylindrical body 13. The upper cylindrical body 11 and the lower cylindrical body 13 are cylindrical members having openings on their upper and lower surfaces, respectively. The partition body 12 is a sheet-like or film-like member, and is disposed between the upper cylindrical body 11 and the lower cylindrical body 13. As a result, in this embodiment, the surface 12a of the partition body 12 constitutes the bottom surface 10b of the container 10. In this embodiment, the upper cylindrical body 11 and the lower cylindrical body 13 are fixed using fixing bolts 14.

[0016] For example, the upper cylindrical body 11 can be made of acrylic, and the lower cylindrical body 13 can be made of stainless steel or acrylic. If the lower cylindrical body 13 is made of stainless steel, the lower cylindrical body 13 can have high durability even if it is thin. If the lower cylindrical body 13 can be made thin, the distance between the subject 91 and the radiation imaging device 20 when capturing the radiation 93a emitted from the subject 91 can be shortened, and a clearer image can be obtained. For the partition 12, a resin sheet or film having a thickness of about 8 μm to about 11 μm can be used. Preferably, the partition 12 is a transparent film made of polyethylene or polyvinylidene chloride having a thickness of about 10 μm. As a result, in this embodiment, the bottom surface 10b of the container 10 can further transmit the light 99 irradiated to the subject 91.

[0017] The subject 91 is placed on the container interior 10c side of the bottom surface 10b of the container 10 together with the culture medium 92, and takes in the radioactive nuclide contained in the culture medium 92. The radioactive nuclide taken in by the subject 91 emits radiation 93a, and an image relating to the dynamics of the substance inside the subject 91 is obtained by the radiation imaging device 100 according to one embodiment. In this embodiment, the subject 91 is a plant, including an agricultural crop.

[0018] The medium 92 contains radioactive nuclides and is placed on the inside 10c of the container 10 on the bottom surface 10b of the container 10 together with the subject 91. The medium 92 is placed so as to cover the periphery of the subject 91, for example. For the medium 92, for example, soil, water, or an artificial medium such as agar or rock wool can be used. In this embodiment, a tube 16 for supplying water or a solution to the medium 92 is provided in the container 10, and it is possible to pour a liquid into the medium 92 placed inside the container using a pump (not shown). This maintains the physiological activity of the subject 91. In this embodiment, the tube 16 is fixed to the upper surface of the container 10 using a fixing member 17 and a fixing bolt 18. For example, the tube 16 is made of stainless steel, and the fixing member 17 is made of acrylic.

[0019] Radionuclides are tracer elements, e.g.32 When P is used, it is mixed in the medium 92 as a compound such as phosphoric acid. The radiation emitted by the radioactive nuclides is, for example, α-rays, β-rays, and γ-rays, and excites the phosphor contained in the scintillator 22, causing the phosphor to emit fluorescence. Examples of radioactive nuclides include 32 Besides P, various commercially available tracer elements can be used. Preferably, the available radionuclides are β-emitting, e.g. 3 H, 14 C. 32 P, 33 P, 35 S, 45 Ca, 87 Rb, 115 In, 176 Radionuclides such as Lu and X-ray emitting nuclides such as 55 Radioactive nuclides such as Fe.

[0020] The light shield 21 blocks light 99 irradiated to the subject 91 and transmits radiation 93a emitted from a radioactive nuclide incorporated in the subject 91. The light shield 21 is disposed on the bottom surface 10b of the container 10 on the outer side of the container. Preferably, the light shield 21 blocks light 99 incident on the scintillator 22 through the opening 10a of the container 10. Illustratively, the light shield 21 may be made of carbon graphite having a thickness of about 10 μm to about 25 μm or aluminum having a thickness of about 12 μm to about 24 μm. More preferably, when carbon graphite is used for the light shield 21, the thickness of the light shield 21 is about 17 μm, and when aluminum is used for the light shield 21, the thickness of the light shield 21 is about 22 μm.

[0021] The scintillator 22 emits fluorescence 93b when irradiated with radiation 93a. The scintillator 22 is disposed on the side of the light shielding body 21 opposite to the side on which the container 10 is disposed. Preferably, the surface of the scintillator 22 facing the container 10 is covered with the light shielding body 21. For example, the scintillator 22 may be terbium-activated gadolinium oxysulfide (GOS) or lutetium aluminum garnet crystal (Lu3Al5O 12 :Ce +) can be used. When irradiated with radiation (e.g., β rays), GOS emits fluorescence at about 540 nm, and LuAG(Ce) emits fluorescence at about 535 nm. Illustratively, when GOS is used for the scintillator 22, the thickness of the scintillator 22 is about 10 μm, and when LuAG(Ce) is used for the scintillator 22, the thickness of the scintillator 22 is about 1 mm.

[0022] In addition to the examples of GOS and LuAG(Ce), the scintillator 22 can be a solid scintillator using crystals or powders of inorganic substances such as NaI, CsI, and ZnS, or crystals of organic substances such as anthracene and naphthalene, or various known liquid scintillators.

[0023] The imaging element 23 captures the fluorescence 93b emitted from the scintillator 22. Illustratively, the imaging element 23 is a CMOS image sensor or a CCD image sensor. Preferably, the imaging element 23 is a photon-counting type CMOS image sensor. In this embodiment, the imaging element 23, together with the light shielding body 21 and the scintillator 22, constitutes the radiation imaging device 20, and the imaging surface of the imaging element 23 captures only the fluorescence 93b emitted from the scintillator 22. The radiation imaging device 20 is attached to a housing 29 via an attachment portion 26. A peripheral circuit (not shown) for reading and processing a signal from the imaging element 23 and a communication interface unit (not shown) for transmitting and receiving data to and from another computer are provided in the housing 29.

[0024] For example, the resolution of the image sensor 23 is about 20 μm, and the image sensor 23 can capture an image every second. When a plant is used as the subject 91, this resolution of about 20 μm is a resolution that allows the degree of accumulation of the radioactive nuclide, which is the tracer element, to be determined for each plant cell. By capturing an image every second, the radiation imaging device 100 according to an embodiment can also obtain video information regarding the dynamics of the substance in the subject 91.

[0025] According to the radiation imaging device of one embodiment and the radiation imaging apparatus including the same, it is possible to obtain an image related to the dynamics of a substance in a living body while maintaining the physiological activity of the living body. The light shielding body 21 is made of a material and has a thickness that blocks the light 99 irradiated to the subject 91 but transmits the radiation 93a emitted from the radioactive nuclide taken up by the subject 91. As a result, the radiation imaging device of one embodiment and the radiation imaging apparatus including the same are able to obtain an image related to the dynamics of a substance in the subject 91 while maintaining the physiological activity of the subject 91 in a state in which the subject 91 is irradiated with light for photosynthesis without being placed in a light-shielded space such as a darkroom.

[0026] [Optical microscope] Fig. 5 is a diagram showing a schematic configuration when a radiation imaging device according to an embodiment is incorporated into an optical microscope. Fig. 6 is a diagram showing a schematic configuration of an optical microscope in which the radiation imaging device shown in Fig. 5 is incorporated.

[0027] As shown in comparison with FIG. 1 and FIG. 5, the light shield 21 and the scintillator 22 included in the radiation imaging device 100 according to one embodiment are attached to an objective lens 41 and incorporated into an optical microscope 200.

[0028] As shown in FIG. 5, the scintillator 22 and the light shielding body 21 are arranged in this order toward the container 10 on the object side 41a of the objective lens 41. The surface of the scintillator 22 facing the container 10 is covered with the light shielding body 21. In this embodiment, the scintillator 22 and the light shielding body 21 are attached to the objective lens 41 using an extendable cylindrical body 42 (lens barrel 42). The space surrounded by the light shielding body 21, the cylindrical body 42, and the objective lens 41, and the optical system from the observation side 41b of the objective lens 41 to the image sensor 23 are light-shielded, and the fluorescence 93b emitted from the scintillator 22 enters the image sensor 23 through the space shielded from ambient light and the light-shielded optical system. In the optical microscope 200 capable of fluorescence observation, the optical system between the observation side 41b of the objective lens 41 and the image sensor 23 is an internal configuration of the optical microscope 200, and is light-shielded to prevent ambient light from entering.

[0029] The optical microscope 200 can switch between a plurality of objective lenses by rotating the revolver 49. The optical microscope 200 can switch between, for example, an objective lens 40 according to an embodiment to which the scintillator 22 and the light shield 21 are attached, and an objective lens 45 for fluorescence observation for observing fluorescence emitted from a subject that has been fluorescently labeled in advance. This allows the optical microscope 200 to perform fluorescence observation and bright-field observation on the same subject 91 from which an image relating to the dynamics of a substance in the subject 91 has been obtained. Note that the same objective lens 45 as that used in fluorescence observation can be used during bright-field observation. Irradiation light is changed between bright-field observation and fluorescence observation.

[0030] [Imaging method] A radiation imaging method according to an embodiment is a method for imaging radiation using a radiation imaging device. The imaging method according to an embodiment described below is similar to the imaging device in terms of common configurations unless otherwise specified, and therefore duplicated descriptions will be omitted.

[0031] A radiation imaging method according to one embodiment includes the steps of placing a subject 91 in a container 10, placing a culture medium 92 containing a radioactive nuclide to be taken up by the subject 91 on the inside 10c side of the container at the bottom surface 10b, and allowing radiation 93a emitted from the radioactive nuclide to pass through the bottom surface 10b, placing a light shield 21 on the outside side of the container at the bottom surface 10b to block light irradiated to the subject 91 and allow radiation 93a to pass through, placing a scintillator 22 on the opposite side of the light shield 21 from the container 10, converting the transmitted radiation 93a into fluorescent light 93b and emitting it, and capturing an image of the fluorescent light 93b emitted from the scintillator 22 using an imaging element 23.

[0032] According to the radiation imaging method of the embodiment, like the radiation imaging device, it is possible to obtain an image of the dynamics of a substance in a living body while maintaining the physiological activity of the living body. Furthermore, for example, when the living body of the subject 91 is a plant and the medium 92 is soil, the radiation imaging method of the embodiment can evaluate the uptake of nutrients in the soil into the plant. Although the degree of adsorption of phosphate differs depending on the soil, according to the radiation imaging method of the embodiment, it is possible to visualize the difference in the ability of each soil to retain inorganic nutrients such as phosphate.

[0033] [Other formats] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0034] In the above embodiment, the surface 12a of the partition 12 forms the bottom surface 10b of the container 10, but the member forming the bottom surface 10b of the container 10 is not limited to the partition 12. Instead of the partition 12, the bottom surface 10b of the container 10 may be formed using a light shielding body 21. In this case, as shown in Fig. 7, the partition 12 is omitted and the light shielding body 21 is integrated with the container 10, so that the surface 21a of the light shielding body 21 facing the container 10 forms the bottom surface 10b of the container 10.

[0035] Furthermore, as long as the medium 92 is one that contains and retains liquid but does not have fluidity, such as soil or rock wool, the radiation imaging device 100 can be configured without the container 10, as shown in Fig. 8. In this case, the radiation imaging device 100 includes a light shielding body 21 on which a subject 91 is placed, the light shielding body 21 having a surface 21a on which a medium 92 containing a radioactive nuclide to be taken up by the subject 91 is placed, the light shielding body 21 shields light 99 irradiated to the subject 91 and transmits radiation 93a emitted from the radioactive nuclide, a scintillator 22 that is disposed on the opposite side of the light shielding body 21 from the medium 92 and emits fluorescence 93b when irradiated with radiation 93a, and an image sensor 23 that images the fluorescence 93b emitted from the scintillator 22.

[0036] Also in this case, the method of imaging radiation using the radiation imaging device 100 from which the container 10 is omitted includes the steps of placing the subject 91 on the light-shielding body 21, placing a culture medium 92 containing a radioactive nuclide to be taken up by the subject 91 on the surface 21a, blocking light 99 irradiated to the subject 91 and allowing radiation 93a emitted from the radioactive nuclide to pass through, arranging a scintillator 22 on the side of the light-shielding body 21 opposite the culture medium 92, converting the transmitted radiation 93a into fluorescent light 93b and emitting it, and imaging the fluorescent light 93b emitted from the scintillator 22 using the imaging element 23.

[0037] In the above-described embodiment, the subject 91 is a plant including an agricultural crop, but the subject 91 is not limited to a plant. The subject 91 may be, for example, a microorganism, a cultured cell, or a sliced ​​tissue section, as long as it is capable of incorporating a radioactive nuclide therein. The radiation imaging instrument and the radiation imaging device including the same according to an embodiment are capable of acquiring an image relating to the dynamics of a substance in such a tissue section in a state in which the tissue section is irradiated with ambient light, without being placed in a light-shielded space such as a darkroom.

[0038] In the above-described embodiment, carbon graphite or aluminum is used for the light shielding body 21, but the material of the light shielding body 21 is not limited to these. The light shielding body 21 may be of any material and have any thickness as long as it blocks the light 99 irradiated to the subject 91 but transmits the radiation 93a, and for example, amorphous carbon may be used for the light shielding body 21.

[0039] In the embodiment described above, the radiation imaging device 100 according to one embodiment is incorporated into the optical microscope 200 illustrated in Fig. 6, but the optical microscope incorporating the imaging device 100 is not limited to this type of microscope. As long as the light for photosynthesis can be irradiated onto the subject 91, the optical microscope incorporating the imaging device 100 is not limited to the inverted microscope illustrated in Fig. 6 and may be an upright microscope. The method of irradiating the subject 91 with light is also not limited to the transmission type illustrated in Fig. 6 and may be an epi-illumination type.

[0040] The following examples of the present invention will make the features of the present invention clearer. EXAMPLES

[0041] In Example 1, a plant was used as a subject, and images relating to the dynamics of substances within the plant were actually obtained. Rice seedlings were prepared as the subject plants, and images were continuously taken of the rice seedlings absorbing phosphoric acid, a fertilizer component. An imaging device without a container (see FIG. 8) was used to obtain the images. The tracer elements were 32 P (hereinafter, also referred to as P-32) was used. Images were taken of each of the roots with different morphologies. The results are shown in Figure 9.

[0042] Figure 9 (A) shows an image comparing the uptake of P-32 tracer (100 kBq) in a crown root without lateral roots (1) and a seminal root with developed lateral roots (2). Areas with high concentrations of P-32 tracer are shown in white in the image. The image also confirmed that P-32 tracer accumulated in the lateral roots of the seminal root with developed lateral roots (2).

[0043] Figure 9(B) is a graph plotting the image intensity every 20 seconds starting 60 seconds after the start of image acquisition. Image intensity was plotted for crown roots without lateral roots (1) and seminal roots with developed lateral roots (2). The image intensity of the roots without lateral roots (1) reached a steady state after 80 seconds, whereas the roots with lateral roots (2) showed 1.4 times the intensity of the roots without lateral roots (1) after about 3 minutes. The signal of the roots with lateral roots (2) continued to increase during the next 10 minutes of imaging. This suggests that the roots with lateral roots have a higher ability to absorb phosphorus, a fertilizer component, and that the absorption contribution differs depending on the root morphology. EXAMPLES

[0044] In Example 2, Arabidopsis thaliana was prepared as a subject plant, and images were continuously acquired during accumulation of phosphoric acid, a fertilizer component, in the roots, in the same manner as in Example 1. The results are shown in FIG.

[0045] Figure 10(A) shows a series of images showing the accumulation of P-32 tracer (100 kBq) in the roots. The first three images of the series were taken within about 1 second of starting imaging. At about 100 milliseconds after the start of imaging (first image), the image is a little blurry, but at about 500 milliseconds (second image), the image is generally clear, and from about 1 second (third image) onwards, clear images with stable image quality were obtained.

[0046] Thus, according to this embodiment, it was shown that a clear image can be obtained even with a short imaging time of about 1 second or less. Since a clear image can be obtained even with a short imaging time, it was shown that when images are taken continuously, the behavior of a substance can be tracked in almost real time. It is expected that a smoother image can be obtained by extending the imaging time of one image.

[0047] Figure 10(B) shows an image of the distribution of P-32 tracer observed after a certain time had passed since the P-32 tracer was absorbed into the roots for 10 minutes. As shown in the figure, it was confirmed that the P-32 tracer was not uniformly accumulated in the root region of Arabidopsis thaliana, but was accumulated in specific cells. [Explanation of symbols]

[0048] 10 containers 11 Upper cylindrical body 12 Partition 13 Lower cylindrical body 14 Fixing bolt 16 tubes 17 Fixing member 18 Fixing bolt 20 Radiation imaging device 21 Shading body 22 Scintillator 23 Image sensor 26 Mounting part 29 Case 40 Objective lens with scintillator and light shield attached 41 Objective Lens 42 Cylindrical body (telescope tube) 45 Objective lens for fluorescence observation 49 Nosepiece 91 Subjects 92 Culture medium 93a Radiation 93b Fluorescence 99 light 100 Imaging device 200 Optical Microscope

Claims

1. a container for accommodating a subject, the container having a bottom surface on an inner side of the container on which a medium containing a radionuclide to be taken in by the subject is placed, the bottom surface being transparent to radiation emitted from the radionuclide; a light shielding body disposed on the bottom surface on an outer side of the container, the light shielding body blocking light irradiated onto the subject and transmitting the radiation; a scintillator that is disposed on the opposite side of the light shielding body from the container and emits fluorescent light when irradiated with the radiation; A radiation imaging device comprising:

2. The imaging apparatus of claim 1 , wherein the bottom surface is further transparent to light that is irradiated onto the subject.

3. The imaging apparatus of claim 1 , wherein the light shield is integral with the container.

4. 4. The imaging apparatus of claim 1, wherein the light blocking body is carbon graphite having a thickness of 10 μm to 25 μm.

5. 4. The imaging apparatus of claim 1, wherein the light shield is aluminum having a thickness of 12 μm to 24 μm.

6. An imaging apparatus according to claim 1 ; an imaging element for imaging the fluorescence emitted from the scintillator; A radiation imaging device comprising:

7. The imaging device of claim 6 , further comprising an objective lens disposed between the scintillator and the image sensor to focus the fluorescent light onto the image sensor.

8. An optical microscope incorporating the imaging device of claim 6.

9. A step of housing a subject in a container, the step being to place a medium containing a radionuclide to be taken up by the subject on the inside of the container at the bottom, and to transmit radiation emitted from the radionuclide through the bottom; a step of placing a light shield on the outer side of the container of the bottom surface to block light irradiated to the subject and transmit the radiation; a step of disposing a scintillator on the opposite side of the light shielding body from the container, converting the transmitted radiation into fluorescent light and emitting the fluorescent light; capturing an image of the fluorescence emitted from the scintillator using an imaging element; A radiation imaging method comprising:

10. a light-shielding body on which a subject is placed, the light-shielding body having a medium containing a radionuclide to be taken up by the subject placed on its surface, the light-shielding body blocking light irradiated onto the subject and transmitting radiation emitted from the radionuclide; a scintillator that is disposed on the opposite side of the light shielding body from the culture medium and emits fluorescence when irradiated with the radiation; an imaging element for imaging the fluorescence emitted from the scintillator; A radiation imaging device comprising:

11. A step of placing a subject on a light-shielding body, the step being to place a medium containing a radionuclide to be taken up by the subject on the surface of the light-shielding body, thereby blocking light irradiated onto the subject and allowing radiation emitted from the radionuclide to pass through; a step of disposing a scintillator on the side of the light shielding body opposite the medium, converting the transmitted radiation into fluorescence and emitting the fluorescence; capturing an image of the fluorescence emitted from the scintillator using an imaging element; A radiation imaging method comprising:

Images