JP2019049438A - Scintillator array, radiation detector, radiation computed tomographic imaging device, and collimator with radiation filter - Google Patents

Abstract

To provide a scintillator array and radiation detector that can detect radiation of two or more different energies.SOLUTION: A scintillator array composed of a plurality of first-dimensionally or two-dimensionally arrayed unit cells comprises: a plurality of scintillator elements 11 that has a first surface and second surface located on a mutually opposite side; and a plurality of radiation filter parts 21. The plurality of scintillator elements 11 includes: a plurality of first scintillator elements 11A; and a plurality of second scintillator elements 11B, and the plurality of radiation filter parts 21 includes a plurality of first radiation filter parts 21B that has a first radiation absorption characteristic. Each unit cell U includes: one of the plurality of first scintillator elements; one of the plurality of second scintillator elements; and one of the plurality of first radiation filter parts. In each unit cell, one of the plurality of first radiation filter parts 21B is selectively arranged above the first surface of one of the plurality of second scintillator elements 11B.SELECTED DRAWING: Figure 1

Description

  The present application relates to a scintillator array, a radiation detector, a radiation computed tomography apparatus and a collimator with a radiation filter.

  In the field of radiation imaging apparatuses, in order to identify the elemental composition of a part constituting the inside of a subject, techniques of detecting radiation of two or more different energies and imaging the subject have been studied. Conventionally, for example, techniques for detecting radiation of two or more different energies by the following method are known. (1) Two or more energy sources irradiate a subject using different radiation sources (Patent Document 1). (2) The drive voltage of the radiation source is switched to irradiate radiation of two or more energy to the subject. (3) A radiation detector in which two or more detectors having different detection sensitivities to radiation energy are stacked is used.

Unexamined-Japanese-Patent No. 2006-167463

  In the method of (1), the entire apparatus becomes large. According to the method of (2), since the timings of applying radiation of different energies are not simultaneous, there is a possibility that the captured image may be blurred when the subject moves. In addition, the number of times of radiation irradiation increases, and the time of radiation irradiation becomes longer. According to the method of (3), the configuration of the radiation detector becomes complicated.

  In view of such problems, the present application provides a scintillator array, a radiation detector, a radiation computed tomography apparatus, and a collimator with a radiation filter, which has a relatively simple structure and can detect radiation of two or more different energies. Do.

  The scintillator array of the present disclosure is a scintillator array constituted by a plurality of unit cells arranged in one or two dimensions, and includes a plurality of scintillator elements having first and second surfaces opposite to each other. And a plurality of radiation filter units, the plurality of scintillator elements including a plurality of first scintillator elements and a plurality of second scintillator elements, and the plurality of radiation filter units have a plurality of first radiation absorption characteristics. Each unit cell includes a first radiation filter unit, and each unit cell includes one of the plurality of first scintillator elements and one of the plurality of second scintillator elements, and one of the plurality of first radiation filter units. In the unit cell, one of the plurality of first radiation filter units is one of the plurality of second scintillator elements. It is selectively positioned above the first surface.

  The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction, and in each unit cell, one of the plurality of first scintillator elements and the plurality of second scintillator elements One of them may be arranged in the first direction.

  The plurality of scintillator elements further include a plurality of third scintillator elements, the plurality of radiation filter units further include a plurality of second radiation filter units having a second radiation absorption characteristic, and each unit cell is a plurality of the plurality of unit cells And one of the plurality of second radiation filter units, and in each unit cell, one of the plurality of second radiation filter units is the one of the plurality of third scintillator elements. It may be selectively disposed above one of the first surfaces.

  The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction, and in each unit cell, one of the plurality of first scintillator elements, the plurality of second scintillator elements And one of the plurality of third scintillator elements may be arranged in the first direction.

  The plurality of scintillator elements further include a plurality of fourth scintillator elements, and the plurality of radiation filter units further include a plurality of third radiation filter units having a third radiation absorption characteristic, and each of the unit cells is The unit further includes one of a plurality of fourth scintillator elements and one of the plurality of third radiation filter units, and in each unit cell, one of the plurality of third radiation filter units is the plurality of fourth scintillator elements It may be selectively disposed above one of the first surfaces.

  The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction, and in each unit cell, one of the plurality of first scintillator elements and the plurality of second scintillator elements And one of the plurality of third scintillator elements and one of the plurality of fourth scintillator elements are arranged in the first direction, and one of the plurality of third scintillator elements is arranged in the first direction. One of the one scintillator element and one of the plurality of second scintillator elements may be adjacent to each other in the second direction.

  The plurality of scintillator elements further include a plurality of fifth scintillator elements and a plurality of sixth scintillator elements, and the plurality of radiation filter units include a plurality of fourth radiation filter units having a fourth radiation absorption characteristic and a fifth radiation The unit cell further includes a plurality of fifth radiation filter units having absorption characteristics, and each unit cell includes one of the plurality of fifth scintillator elements, one of the plurality of sixth scintillator elements, and the plurality of fourth radiation filter units. And one of the plurality of fifth radiation filter units, and in each unit cell, one of the plurality of fourth radiation filter units and one of the plurality of fifth radiation filter units are the Above the plurality of first surfaces of one of a plurality of fifth scintillator elements, and the plurality of ones of a sixth scintillator element One of the plurality of fifth scintillator elements and one of the plurality of sixth scintillator elements are arranged in the second direction in each unit cell, and each of the unit cells is selectively disposed. And one of the plurality of fifth scintillator elements and one of the plurality of sixth scintillator elements are respectively one of the plurality of second scintillator elements and one of the plurality of fourth scintillator elements in the first direction. It may be adjacent.

  The plurality of scintillator elements further include a plurality of seventh scintillator elements, a plurality of eighth scintillator elements, and a plurality of ninth scintillator elements, and the plurality of radiation filter units have a plurality of sixth radiation absorption characteristics. A radiation filter unit, a plurality of seventh radiation filter units having seventh radiation absorption characteristics, and a plurality of eighth radiation filter units having eighth radiation absorption characteristics, each unit cell comprising the seventh scintillator elements One, one of the plurality of eighth scintillator elements, one of the plurality of ninth scintillator elements, one of the plurality of sixth radiation filter units, and one of the plurality of seventh radiation filter units, And one of a plurality of seventh radiation filter units, and in each unit cell, the plurality of sixth radiation filters One of the plurality of seventh radiation filter portions, and one of the plurality of eighth radiation filter portions are disposed above the first surface of one of the plurality of seventh scintillator elements, And the first surface of one of the eight scintillator elements and the first surface of one of the ninth scintillator elements are selectively disposed, respectively, in each unit cell. One of the seven scintillator elements, one of the plurality of eighth scintillator elements, and one of the plurality of ninth scintillator elements are arranged in the first direction, and one of the plurality of seventh scintillator elements One, one of the plurality of eighth scintillator elements, and one of the plurality of ninth scintillator elements is one of the plurality of third scintillator elements, the plurality of fourth scintillator elements May be adjacent to each at one and one said second direction of the plurality of sixth scintillator element.

  Each of the plurality of first radiation filter parts is at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni, Cu, Mo, Ag, Ta, W, Pt and Au. May be included.

  Each of the plurality of first radiation filter portions includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, Each of the two radiation filter parts may include a second metal plate made of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt and Au.

  Each of the plurality of first radiation filter portions includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, Each of the two radiation filter units includes a second metal plate made of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt, and Au, and each of the plurality of third radiation filter units includes: It is selected from the group consisting of Mo, Ag, Ta, W, Pt and Au, and the first metal plate consisting of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu And a second metal plate made of at least one element, wherein the first metal plate of the plurality of first radiation filter portions and the plurality of third radiation filter portions The first metal plates are connected to each other in the second direction, and the second metal plates of the plurality of second radiation filter units and the second metal plates of the plurality of third radiation filter units are the first In the direction of, they may be connected to each other.

  The scintillator array may further include reflective members disposed between the plurality of scintillator elements and on the first surface of the plurality of scintillator elements.

  The scintillator array may further comprise a collimator disposed on the reflective member.

  A part of the collimator may be inserted into the reflecting member.

  The plurality of radiation filter portions may be provided on the reflection member.

  The collimator may have a grid shape surrounding an area above the plurality of first surfaces of each scintillator element, and the plurality of radiation filter units may be selectively provided in a part of the grid shape.

  The radiation detector of the present disclosure includes the scintillator array according to any one of the above and a plurality of light detection elements arranged to face the second surface of the plurality of scintillator elements of the scintillator array.

  A radiation computed tomography apparatus of the present disclosure includes a radiation source, the radiation detector, the radiation source, and a control unit that processes a detection signal output from the radiation detector.

  The radiation-filtered collimator of the present disclosure is a radiation-filtered collimator disposed on the incident surface of an array section including a plurality of scintillator elements arranged in one or two dimensions, and includes a plurality of shielding plates and a plurality of radiations. And a plurality of collimating spaces arranged in one dimension or two dimensions on the incident plane, the plurality of shielding plates having a predetermined height in a direction perpendicular to the incident plane. The plurality of radiation filter sections are selectively disposed in at least a portion of the plurality of collimated spaces, and the plurality of shielding plates block or attenuate the radiation, and the plurality of radiation filters are formed. The part has a predetermined radiation absorption characteristic.

  The plurality of collimating spaces are arranged in a first direction, and each of the plurality of collimating spaces has a strip shape extending in a second direction different from the first direction, and the plurality of collimating spaces are the first The plurality of first collimating spaces and the plurality of second collimating spaces alternately arranged in the direction, and the plurality of radiation filter units include a plurality of first radiation filter units having a first radiation absorption characteristic, and the plurality The first radiation filter unit may be disposed in each of the plurality of second collimating spaces.

  The plurality of collimating spaces include a plurality of third collimating spaces, the plurality of radiation filter units include a plurality of second radiation filter units having a second radiation absorption characteristic, and the plurality of second radiation filter units are Each of the plurality of third collimating spaces may be disposed.

  The plurality of collimated spaces are two-dimensionally arranged in a first direction and a second direction different from the first direction, each of the plurality of collimated spaces has a rectangular shape, and the plurality of collimated spaces are a plurality of The first collimating space, the plurality of second collimating spaces, the plurality of third collimating spaces, and the plurality of fourth collimating spaces, each of the first collimating space, the second collimating space, the third collimating space and the fourth collimating space The plurality of radiation filter units are arranged in two rows and two columns adjacent to one direction and the second direction, and the plurality of radiation filter units have a plurality of first radiation filter units having a first radiation absorption characteristic, and a second radiation absorption characteristic A plurality of first radiation filters and a plurality of third radiation filters having a third radiation absorption characteristic; Are disposed in the plurality of second collimating spaces, the plurality of second radiation filter portions are respectively disposed in the plurality of third collimating spaces, and the plurality of third radiation filter portions are disposed in the plurality of fourth collimating spaces. It may be disposed in the collimating space, respectively.

  According to the present disclosure, a scintillator array capable of detecting radiation of two or more different energies, a radiation detector, a radiation computed tomography apparatus, and a collimator with a radiation filter are realized.

(A) And (b) is a top view and sectional drawing of the scintillator array by 1st Embodiment, (c) is a top view of the scintillator by other examples. (A) And (b) is a top view and sectional drawing of a scintillator array by a 2nd embodiment. (A) is a top view of the scintillator array by 3rd Embodiment, (b) and (c) is sectional drawing of a scintillator array. (A) is a top view of the scintillator array by 4th Embodiment, (b) and (c) is sectional drawing of a scintillator array. (A) is a top view of the scintillator array by 5th Embodiment, (b) (c) and (d) is sectional drawing of a scintillator array. (A) And (b) is a top view and sectional drawing of the scintillator array by 6th Embodiment, (c) is a top view of a collimator with a radiation filter. (A) And (b) is a top view and sectional drawing of the scintillator array by the other example of 6th Embodiment, (c) is a top view of a collimator with a radiation filter. (A) And (b) is a top view and a sectional view of a scintillator array according to a seventh embodiment. (A) And (b) is a top view and sectional drawing of the radiation detector by 8th Embodiment. It is a figure which shows energy distribution of the X-ray which permeate | transmitted 1 mm, 3 mm, and 5 mm thick Al plate. It is a figure which shows energy distribution of the X-ray which permeate | transmitted 1 mm and 3 mm-thick Cu board. It is a figure which shows energy distribution of the X-ray which permeate | transmitted the metal plate of a different element.

  Hereinafter, embodiments of the scintillator array, radiation detector, radiation computed tomography apparatus, and collimator with radiation filter will be described with reference to the drawings. The scintillator array and radiation detector of the present disclosure can be suitably used for medical radiation imaging devices such as X-ray CT imaging devices and industrial radiation imaging devices such as industrial X-ray inspection devices. In the present disclosure, radiation includes X-rays, γ-rays, positrons and the like. Moreover, in the following embodiments, the same reference numerals may be given to the same components and the detailed description may be omitted.

First Embodiment
Fig.1 (a) is a top view of the scintillator array 101 of this embodiment, FIG.1 (b) is sectional drawing of the scintillator array 101 in the 1B-1B line of Fig.1 (a). The scintillator array 101 includes a plurality of scintillator elements 11 and a plurality of radiation filter units 21. The plurality of scintillator elements 11 are arranged in one or two dimensions. In the present embodiment, as shown in FIG. 1A, the plurality of scintillator elements 11 are arranged in two dimensions, in the x direction of the xy plane and in the y direction. In the following embodiments, the scintillator array comprises the scintillator elements 11 arranged in a 6 × 4 array or the scintillator elements 11 arranged in a 6 × 6 array, but the number of scintillator elements is not limited to these examples. It is not limited to. Moreover, in the following examples, although the repeating unit of the periodic structure in a scintillator array is mainly demonstrated, the repeating unit provided with the same structure is arrange | positioned according to the number of scintillators.

  Each scintillator element 11 has a first surface 11 a and a second surface 11 b located opposite to the first surface 11 a. In the present embodiment, the first surface 11a and the second surface 11b have a rectangular shape. For this reason, the scintillator element 11 further has four side surfaces.

The scintillator element 11 includes a light emitting material or a fluorescent material that emits light such as fluorescence upon incidence of radiation. For example, the scintillator element 11 may be made of a ceramic scintillator material such as gadolinium oxysulfide (GOS) or gadolinium-gallium-aluminum garnet (GGAG). GOS has a composition of Gd ₂ O ₂ S activated with at least one selected from, for example, Pr, Ce and Tb. GGAG, for example Ce, and activated with at least one member selected from Pr, etc. _{(Gd 1-x Lu x)} 3 + a (Ga u Al 1-u) 5-a O 12 (x = 0~0.5, u It has a main composition of = 0.2 to 0.6, and a =-0.05 to 0.15). What substituted at least one part of this Gd to Y may be used. The luminescent or fluorescent material by radiation is not limited to the examples described above. The scintillator element 11 may be made of another fluorescent material.

  In the present embodiment, the scintillator array 101 further includes a reflecting member 31. The reflecting member 31 is located between the plurality of scintillator elements 11 and on the first surface 11 a of each scintillator element 11. The reflecting member 31 has a characteristic of reflecting the light emitted by the scintillator element 11. For example, the reflective member 31 includes white titanium oxide powder and a resin such as epoxy. The light generated by the radiation incident on each scintillator element 11 is incident on the adjacent scintillator element 11 by the reflection member 31 and is suppressed from being detected by the light detection element provided on the adjacent scintillator element 11. That is, crosstalk in the scintillator array 101 is suppressed. The plurality of scintillator elements 11 provided with the reflection member 31 are referred to as an array unit 41.

  As shown in FIG. 1A, the plurality of scintillator elements 11 include a plurality of first scintillator elements 11A and a plurality of second scintillator elements 11B. The scintillator array 101 is composed of a plurality of unit cells U arranged in one or two dimensions in the xy plane. The unit cell U includes one of the plurality of first scintillator elements 11A and one of the plurality of second scintillator elements 11B. In the present embodiment, in each unit cell U, the first scintillator element 11A and the second scintillator element 11A are included. The scintillator elements 11B are arranged in the x direction. Further, the plurality of radiation filter units 21 include a plurality of first radiation filter units 21B.

  The unit cells U are two-dimensionally arranged along the x direction and the y direction. In each unit cell U, one of the plurality of first radiation filter units 21 (21B) is selectively disposed above the first surface 11a of the second scintillator element 11B. In the present embodiment, the first radiation filter unit 21 (21B) is disposed on the reflecting member 31 covering the first surfaces 11a of the plurality of second scintillator elements 11B. That is, the first radiation filter unit 21 (21B) is disposed above the first surface 11a of the plurality of second scintillator elements 11B via the reflection member 31.

  The first radiation filter unit 21 (21B) has a first radiation absorption characteristic. The first radiation filter unit 21 (21B) selectively absorbs and attenuates part of energy components of incident radiation, and transmits other components. Here, the absorption means absorbing radiation at a rate of more than 0 and 100% or less. More specifically, the first radiation filter portion 21 (21B) is selected from the group consisting of Mg, Al, Ti, Sn, Fe, Co, Ni, Cu, Mo, Ag, Ta, W, Pt and Au. It has a metal plate containing at least one element, or a resin layer in which metal powder of at least one of these elements is dispersed. The thickness of the metal plate or the resin layer is, for example, about several hundred μm to several mm.

  In the present embodiment, in the array of the plurality of scintillator elements 11, the first scintillator elements 11A and the second scintillator elements 11B are alternately positioned in the x direction, and the first scintillator elements 11A and the second scintillator elements 11A are in the y direction. The scintillator elements 11B are each continuous. For this reason, the metal plates included in the plurality of first radiation filter portions 21 are connected to one another in the y direction, and are strip-shaped positioned above the first surfaces 11a of the plurality of second scintillator elements 11B and extending in the y direction. The first radiation filter plate 22B is configured. The first radiation filter plate 22B is fixed to, for example, the surface 31a of the reflecting member 31 located above the first surface 11a of the second scintillator element 11B by an adhesive or the like. The surface of the scintillator array 101 provided with the first radiation filter plate 22B is referred to as an incident surface 101a. However, the metal plates included in the plurality of first radiation filter units 21 (21B) may not be connected to each other. In this case, as shown in FIG. 1 (c), the plurality of first radiation filter pieces 22B 'are located above the first surfaces 11a of the plurality of second scintillator elements 11B.

  When radiation, for example, X-rays, enter the incident surface 101a of the scintillator array 101, X-rays of the same energy distribution enter the unit cell U, and if the attenuation of X-rays at the reflecting member 31 is not taken into consideration, the first X-rays having the same energy distribution as the X-rays incident on the unit cell U are incident on the first surface 11 a of the scintillator element 11A. On the other hand, X-rays transmitted through the first radiation filter section 21B and having a part of energy band components attenuated are incident on the first surface 11a of the second scintillator element 11B. Therefore, it is possible to simultaneously detect X-rays of different energy by the first scintillator element 11A and the second scintillator element 11B.

  The positions of the first surface 11a of the first scintillator element 11A and the first surface 11a of the second scintillator element 11B are not the same in the xy plane. However, by performing image processing with unit cell U as one pixel, it is possible to realize a dual energy scintillator array. For example, light detection elements are respectively provided on the second surface 11b of the first scintillator element 11A and the second surface 11b of the second scintillator element 11B, and the two detection signals obtained by fluorescence are X-rays of different energies in the same pixel Image processing as a signal by In addition, when acquiring data also in three dimensions, ie, the thickness direction, or performing image processing using the scintillator array 101, the unit cell U constitutes one voxel.

  According to the above-described signal processing, the number of pixels is halved with respect to the number of scintillator elements 11 in the x direction. In order to make the number of pixels the same as the number of scintillator elements 11, data may be generated by interpolation during image processing. For example, the average of the signal S1 by the light detection element that detects the fluorescence of the first scintillator element 11A of the unit cell U and the signal S2 by the light detection element that detects the fluorescence of the first scintillator element 11A of the adjacent unit cell U The obtained signal and the signal from the light detection element that detects the fluorescence of the second scintillator element 11B of the unit cell U may be subjected to image processing as two signals of X-rays of different energy in the same pixel. A reduction in resolution can be suppressed by performing such signal processing also on the signal from the light detection element that detects the fluorescence of the second scintillator element 11B of each unit cell U.

  The scintillator array 101 can be manufactured, for example, by forming the array unit 41 and arranging a metal plate to be the plurality of radiation filter units 21 on the upper surface 31 a of the array unit 41. The array unit 41 can be manufactured by, for example, the manufacturing method disclosed in JP-A-2017-37096, JP-A-2015-172580, and JP-A-2013-228355. The first radiation filter plate 22B is disposed so as to cover the upper side of the first surface 11a of the second scintillator element 11B on the upper surface 31a of the array unit 41 created. The first radiation filter plate 22B can be fixed to the upper surface 41a by, for example, an adhesive. Thereby, the scintillator array 101 is completed.

  In the scintillator array 101, the array unit 41 has a single energy scintillator array structure, and can be manufactured by a known manufacturing method as described above. Thus, dual energy scintillator arrays can be manufactured without major changes in the structure of the single energy scintillator array, ie without significant increases in manufacturing costs. Moreover, according to the scintillator array 101 of the present disclosure, radiation can be detected in two different energy bands without irradiating radiation of a plurality of energies simultaneously or switching. Therefore, in the radiation computed tomography apparatus provided with the scintillator array 101 of the present disclosure, the number of radiation sources can be reduced to one, and control of the radiation sources can be simplified.

Second Embodiment
Fig.2 (a) is a top view of the scintillator array 102 of this embodiment, FIG.2 (b) is sectional drawing of the scintillator array 102 in the 2B-2B line of Fig.2 (a). The scintillator array 102 is different from the scintillator array 101 of the first embodiment in that a unit cell U includes three scintillator elements.

  As shown in FIG. 2A, the plurality of scintillator elements 11 include a plurality of first scintillator elements 11A, a plurality of second scintillator elements 11B, and a plurality of third scintillator elements 11C. The unit cell U includes one of the plurality of first scintillator elements 11A, one of the plurality of second scintillator elements 11B, and one of the plurality of third scintillator elements 11C, and in the present embodiment, each unit cell In U, the first scintillator element 11A, the second scintillator element 11B, and the third scintillator element 11C are arranged in the x direction.

  The plurality of radiation filter units 21 includes a plurality of first radiation filter units 21B and a plurality of second radiation filter units 21C. In each unit cell U, one of the plurality of first radiation filter units 21B and one of the plurality of second radiation filter units 21C are located above the first surface 11a of the second scintillator element 11B and the third scintillator It is selectively disposed above the first surface 11a of the element 11C. In the present embodiment, the plurality of first radiation filter units 21B and the plurality of second radiation filter units 21C are disposed on the reflective member 31 covering the first surfaces 11a of the plurality of scintillator elements 11.

  The second radiation filter unit 21C has a second radiation absorption characteristic. The second radiation filter unit 21C selectively absorbs and attenuates part of energy components of the incident radiation, and transmits other components. Similar to the first radiation filter unit 21B, the second radiation filter unit 21C is more specifically Mg, Al, Ti, Sn, Fe, Co, Ni, Cu, Mo, Ag, Ta, W, Pt and Au. The metal plate containing the at least 1 element chosen from the group which consists of, or the resin layer which the metal powder of these at least 1 sort (s) of elements disperse | distributed. The thickness of the metal plate is, for example, about several hundred μm to several mm.

  The second radiation absorption characteristic is different from the first radiation absorption characteristic. For this reason, the element which comprises the metal plate contained in 1st radiation filter part 21B and the element which comprises the metal plate contained in 2nd radiation filter part 21C differ. Alternatively, when the metal plate of the second radiation filter unit 21C is formed of the same element as the metal plate of the first radiation filter unit 21B, the radiation absorption characteristics of the two filter units are different due to the difference in thickness of the metal plate. .

  Preferably, the metal plate included in the first radiation filter portion 21B is made of one of the above elements, the first metal having a relatively small specific gravity, and the second metal having a relatively large specific gravity, and the second radiation The metal plate included in the filter portion 21C is made of the other of the first metal and the second metal. Among the above elements, the first metal having a relatively small specific gravity is, for example, Mg, Al, Ti, Sn, Fe, Co, Ni and Cu, and the second metal having a relatively large specific gravity is, for example, Mo, Ag , Ta, W, Pt and Au. For example, the first radiation filter unit 21B includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Sn, Fe, Co, Ni, and Cu, and the second radiation filter unit 21C. Includes a second metal plate made of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt and Au.

  Alternatively, the metal plate included in the first radiation filter unit 21B and the metal plate included in the second radiation filter unit 21C may be respectively configured by two different elements selected from the above-described first metals, It may be respectively composed of two different elements selected from two metals.

  Similar to the first embodiment, the metal plates included in the plurality of second radiation filter units 21C are connected to one another in the y direction, and are positioned above the first surface 11a of the plurality of third scintillator elements 11C. The radiation filter plate 22C is configured. For example, the second radiation filter plate 22C is fixed to the surface 31a of the reflecting member 31 located above the first surface 11a of the third scintillator element 11C by an adhesive or the like. The same reference numerals as in FIG. 1 are used for the same members, for example.

  When radiation, for example, X-rays, enter the incident surface 102a of the scintillator array 102, X-rays of the same energy distribution enter the unit cell U, and if attenuation of X-rays at the reflecting member 31 is not taken into consideration, the first X-rays having the same energy distribution as the X-rays incident on the unit cell U are incident on the first surface 11 a of the scintillator element 11A. On the other hand, X-rays transmitted through the first radiation filter section 21B and having a part of energy band components attenuated are incident on the first surface 11a of the second scintillator element 11B. In addition, in the first surface 11a of the third scintillator element 11C, the component of the energy band different from the X-rays transmitted through the second radiation filter portion 21C and incident on the first surface 11a of the second scintillator element 11B is attenuated. X-rays are incident. Therefore, it is possible to simultaneously detect X-rays of different energies by the first scintillator element 11A, the second scintillator element 11B and the third scintillator element 11C.

  In the present embodiment, the unit cell U includes three scintillator elements 11. A multi-energy scintillator array can be realized by performing image processing with unit cell U as one pixel. Further, as described in the first embodiment, in order to make the number of pixels in the x direction be the same as the number of scintillator elements 11, data may be generated by interpolation in image processing.

Third Embodiment
Fig.3 (a) is a top view of the scintillator array 103 of this embodiment, FIG.3 (b) and FIG.3 (c) are the scintillator arrays in the 3B-3B line and 3C-3C line of FIG. 3 (a). FIG. The scintillator array 103 is different from the scintillator array 101 of the first embodiment in that the unit cell U includes four scintillator elements.

  As shown in FIG. 3A, the plurality of scintillator elements 11 include a plurality of first scintillator elements 11A, a plurality of second scintillator elements 11B, a plurality of third scintillator elements 11C, and a plurality of fourth scintillator elements 11D. . The unit cell U includes one of a plurality of first scintillator elements 11A, one of a plurality of second scintillator elements 11B, one of a plurality of third scintillator elements 11C, and one of a plurality of fourth scintillator elements 11D. It is. In the present embodiment, in each unit cell U, the first scintillator elements 11A and the second scintillator elements 11B are arranged in the x direction. The third scintillator element 11C and the fourth scintillator element 11D are arranged in the x direction, and are adjacent to the first scintillator element 11A and the second scintillator element 11B in the y direction.

  The plurality of radiation filters 21 includes a plurality of first radiation filters 21B, a plurality of second radiation filters 21C, and a plurality of third radiation filters 21D. In each unit cell U, one of the plurality of first radiation filter units 21B, one of the plurality of second radiation filter units 21C, and one of the plurality of third radiation filter units 21D are second It is selectively disposed above the first surface 11a of the scintillator element 11B, above the first surface 11a of the third scintillator element 11C, and above the first surface 11a of the fourth scintillator element 11D. In the present embodiment, the plurality of second radiation filter units 21C and the plurality of third radiation filter units 21D are disposed on the reflective member 31 covering the first surfaces 11a of the plurality of scintillator elements 11.

  The first radiation filter unit 21B, the second radiation filter unit 21C, and the third radiation filter unit 21D each have a first radiation absorption characteristic, a second radiation absorption characteristic, and a third radiation absorption characteristic. The first radiation filter unit 21B, the second radiation filter unit 21C, and the third radiation filter unit 21D selectively absorb and attenuate a part of energy components of the incident radiation, and transmit other components. In the first radiation filter unit 21B, the second radiation filter unit 21C, and the third radiation filter unit 21D, the energy components to be absorbed and the ratio thereof are different from each other. More specifically, the first radiation filter unit 21B, the second radiation filter unit 21C, and the third radiation filter unit 21D are Mg, Al, Ti, Sn, Fe, Co, Ni, Cu, Mo, Ag, Ta, It has a metal plate containing at least one element selected from the group consisting of W, Pt and Au, or a resin layer in which metal powder of at least one of these elements is dispersed. The thickness of the metal plate is, for example, about several hundred μm to several mm.

  In the present embodiment, the first radiation filter unit 21B includes the first metal plate, the second radiation filter unit 21C includes the second metal plate, and the third radiation filter unit 21D includes the first metal plate and the second metal plate. Including the board. The first metal plate is formed of one of the above elements, the first metal having a relatively small specific gravity, and the second metal having a relatively large specific gravity, and the metal plate included in the second radiation filter portion 21C is And the other of the first metal and the second metal. Among the above elements, the first metal having a relatively small specific gravity is, for example, Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, and the second metal having a relatively large specific gravity is, for example, Mo, Ag , Ta, W, Pt and Au. For example, the first radiation filter portion 21B includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, and the second radiation filter portion 21C Includes a second metal plate made of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt and Au. Further, the third radiation filter unit 21D includes a first metal plate and a second metal plate made of these elements.

  The first metal plates included in the plurality of first radiation filter units 21B are connected to each other in the y direction, and the first metal plates of the plurality of second scintillator elements 11B are arranged above the first surface 11a and the plurality of fourth scintillator elements 11D. A strip-shaped first radiation filter plate 22B is formed above the surface 11a and extends in the y direction. Further, the second metal plates included in the plurality of second radiation filter units 21C are connected to each other in the x direction, and above the first surface 11a of the plurality of third scintillator elements 11C and of the plurality of fourth scintillator elements 11D. A strip-shaped second radiation filter plate 22C which is located above the first surface 11a and extends in the x direction is configured. Therefore, the first radiation filter plate 22B and the second radiation filter plate 22C are located above the first surface 11a of the fourth scintillator element 11D in a crossing state. As shown in FIG. 3B, in the present embodiment, the first radiation filter plate 22B is located above the first surface 11a of the second scintillator element 11B and above the first surface 11a of the fourth scintillator element 11D. The surface 31 a of the reflection member 31 is fixed by an adhesive or the like. Further, as shown in FIG. 3C, in the present embodiment, the second radiation filter plate 22C is located above the first surface 11a of the second scintillator element 11B and above the first surface 11a of the fourth scintillator element 11D. The first radiation filter plate 22B is fixed by an adhesive or the like. However, the second radiation filter plate 22C may be fixed to the surface 31a of the reflecting member 31, and the first radiation filter plate 22B may be fixed to the second radiation filter plate 22C.

  When radiation, for example, X-rays, enter the incident surface 103a of the scintillator array 103, X-rays of the same energy distribution enter the unit cell U, and if the attenuation of X-rays at the reflecting member 31 is not taken into consideration, the first X-rays having the same energy distribution as the X-rays incident on the unit cell U are incident on the first surface 11 a of the scintillator element 11A. On the other hand, X-rays transmitted through the first radiation filter section 21B and having a part of energy band components attenuated are incident on the first surface 11a of the second scintillator element 11B. In addition, in the first surface 11a of the third scintillator element 11C, the component of the energy band different from the X-rays transmitted through the second radiation filter portion 21C and incident on the first surface 11a of the second scintillator element 11B is attenuated. X-rays are incident. The first surface 11a of the fourth scintillator element 11D transmits X-rays transmitted through the third radiation filter portion 21D and incident on the first surface 11a of the second scintillator element 11B and the first surface 11a of the third scintillator element 11C X-rays are incident with components of different energy bands attenuated. Therefore, it is possible to simultaneously detect X-rays of different energies by the first scintillator element 11A, the second scintillator element 11B, the third scintillator element 11C and the fourth scintillator element 11D.

  In the present embodiment, the unit cell U includes four scintillator elements 11. A multi-energy scintillator array can be realized by performing image processing with unit cell U as one pixel. Further, as described in the first embodiment, in order to make the number of pixels in the x direction and y direction the same as the number of scintillator elements 11, data may be generated by interpolation in image processing.

  Further, in the present embodiment, the third radiation filter portion 21D includes the first metal plate and the second metal plate, but a third metal plate configured by an element different from the first metal plate and the second metal plate. May be included. In this case, the first metal plate of the first radiation filter portion 21B and the second metal plate of the second radiation filter portion 21C have a rectangular shape not connected to the metal plate on the adjacent element preferable.

Fourth Embodiment
FIG. 4 (a) is a plan view of the scintillator array 104 according to the present embodiment, and FIGS. 4 (b) and 4 (c) are scintillator arrays taken along lines 4B-4B and 4C-4C of FIG. 4 (a). 10 is a cross-sectional view of FIG. The scintillator array 104 is different from the scintillator array 101 of the first embodiment in that the unit cell U includes six scintillator elements. The positions and structures of the first scintillator element 11A to the fourth scintillator element 11D and the first radiation filter unit 21B to the third radiation filter unit 21D are the same as, for example, the scintillator array 103 of the third embodiment. Hereinafter, points different from the scintillator array 103 will be particularly described.

  As shown in FIG. 4A, the plurality of scintillator elements 11 further include a plurality of fifth scintillator elements 11E and a plurality of sixth scintillator elements 11F. The unit cell U further includes one of the plurality of fifth scintillator elements 11E and one of the plurality of sixth scintillator elements 11F. In the present embodiment, in each unit cell U, the fifth scintillator element 11E and the sixth scintillator element 11F are arranged in the y direction, and are adjacent to the second scintillator element 11B and the fourth scintillator element 11D in the x direction. ing.

  The plurality of radiation filter units 21 further include a plurality of fourth radiation filter units 21E and a plurality of fifth radiation filter units 21F. In each unit cell U, one of the plurality of fourth radiation filter units 21E and one of the plurality of fifth radiation filter units 21F are located above the first surface 11a of the fifth scintillator element 11E and the sixth scintillator It is selectively disposed above the first surface 11a of the element 11F. In the present embodiment, the plurality of fourth radiation filter units 21E and the plurality of fifth radiation filter units 21F are disposed on the reflecting member 31 covering the first surfaces 11a of the plurality of scintillator elements 11.

  The fourth radiation filter unit 21E and the fifth radiation filter unit 21F each have a fourth radiation absorption characteristic and a fifth radiation absorption characteristic. The fourth radiation filter unit 21E and the fifth radiation filter unit 21F selectively absorb and attenuate part of energy components of the incident radiation, and transmit other components. In the first radiation filter unit 21B to the fifth radiation filter unit 21F, the energy components to be absorbed and the ratio thereof are different from each other.

  The fourth radiation filter unit 21E and the fifth radiation filter unit 21F are also metal plates containing at least one element selected from the group consisting of Al, Ti, Fe, Co, Ni, Ag, Sn, Ta, W, Pt and Au. Or it has the resin layer which the metal powder of these at least 1 sort (s) of elements disperse | distributed. The thickness of the metal plate is, for example, about several hundred μm to several mm.

  In the present embodiment, the fourth radiation filter unit 21E includes a fourth metal plate. The fourth metal plate is formed of one of the above elements, the first metal having a relatively small specific gravity, and the second metal having a relatively large specific gravity. Preferably, the fourth metal plate is made of an element different from the first metal plate and the second metal plate. The fifth radiation filter unit 21F includes a second metal plate and a fourth metal plate.

  The fourth metal plates included in the plurality of fourth radiation filter units 21E are connected to one another in the y direction, and the first metal plates of the plurality of sixth scintillator elements 11F are arranged above the first surface 11a of the plurality of fifth scintillator elements 11E. A strip-shaped fourth radiation filter plate 22E which is located above the surface 11a and extends in the y direction is configured. Above the first surface 11a of the sixth scintillator element 11F, the second radiation filter plate 22C and the fourth radiation filter plate 22E are positioned in a state of crossing each other. As shown in FIG. 4B, in the present embodiment, the fourth radiation filter plate 22E is located above the first surface 11a of the fifth scintillator element 11E and above the first surface 11a of the sixth scintillator element 11F. The surface 31 a of the reflection member 31 is fixed by an adhesive or the like. Further, as shown in FIG. 4C, in the present embodiment, the second radiation filter plate 22C is fixed to the first radiation filter plate 22B and the fourth radiation filter plate 22E by an adhesive or the like. However, the fourth radiation filter plate 22E may be fixed to the surface 31a of the reflecting member 31, and the first radiation filter plate 22B and the fourth radiation filter plate 22E may be fixed to the second radiation filter plate 22C.

  When radiation, for example, X-rays, enter the incident surface 104a of the scintillator array 104, X-rays of the same energy distribution enter the unit cell U, and if attenuation of X-rays at the reflecting member 31 is not taken into consideration, the first X-rays having the same energy distribution as the X-rays incident on the unit cell U are incident on the first surface 11 a of the scintillator element 11A. On the other hand, X ray which penetrates the 5th radiation filter part 21F from the 1st radiation filter part 21B to the 6th scintillator element 11F from the 1st surface 11a of the 2nd scintillator element 11B, and a part of energy band ingredient has attenuated Is incident. Therefore, it is possible to simultaneously detect X-rays of different energies by the first scintillator element 11A to the sixth scintillator element 11F.

  In the present embodiment, the unit cell U includes six scintillator elements 11. A multi-energy scintillator array can be realized by performing image processing with unit cell U as one pixel. Further, as described in the second embodiment, in order to make the number of pixels in the x direction and y direction the same as the number of scintillator elements 11, data may be generated by interpolation in image processing.

  In the present embodiment, the fifth radiation filter portion 21F includes the second metal plate and the fourth metal plate, but is a fifth metal plate formed of an element different from the second metal plate and the fourth metal plate. May be included. In this case, the first metal plate of the first radiation filter portion 21B, the second metal plate of the second radiation filter portion 21C, and the fourth metal plate of the fourth radiation filter portion 21E are connected to the metal plates on adjacent elements. It is preferable to have the rectangular shape which is not carried out.

Fifth Embodiment
5 (a) is a plan view of the scintillator array 105 of this embodiment, and FIGS. 5 (b), 5 (c) and 5 (d) are lines 5B-5B, 5C of FIG. 5 (a). It is sectional drawing of the scintillator array 105 in -5C line and 5D-5D line.

  The scintillator array 105 is different from the scintillator array 104 of the fourth embodiment in that the unit cell U includes nine scintillator elements. The positions and structures of the first scintillator element 11A to the sixth scintillator element 11F and the first radiation filter unit 21B to the fifth radiation filter unit 21F are the same as, for example, the scintillator array 104 of the fourth embodiment. Hereinafter, points different from the scintillator array 104 will be particularly described.

  As shown in FIG. 5A, the plurality of scintillator elements 11 further include a plurality of seventh scintillator elements 11G, a plurality of eighth scintillator elements 11H, and a plurality of ninth scintillator elements 11I. Further, the unit cell U further includes one of the plurality of seventh scintillator elements 11G, one of the plurality of eighth scintillator elements 11H, and one of the plurality of ninth scintillator elements 11I. In the present embodiment, in each unit cell U, the seventh scintillator element 11G, the eighth scintillator element 11H and the ninth scintillator element 11I are arranged in the x direction, and the third scintillator element 11C, the fourth scintillator element 11D and The sixth scintillator element 11F is adjacent to each other in the y direction.

  The plurality of radiation filters 21 further include a plurality of sixth radiation filters 21G, a plurality of seventh radiation filters 21H, and a plurality of eighth radiation filters 21I. In each unit cell U, one of the plurality of sixth radiation filter units 21G, one of the plurality of seventh radiation filter units 21H and one of the plurality of eighth radiation filter units 21I are the seventh It is selectively disposed above the first surface 11a of the scintillator element 11G, above the first surface 11a of the eighth scintillator element 11H, and above the first surface 11a of the ninth scintillator element 11I. In the present embodiment, the plurality of sixth radiation filter units 21G, the plurality of seventh radiation filter units 21H, and the plurality of eighth radiation filter units 21I are disposed on the reflecting member 31 covering the first surface 11a of the plurality of scintillator elements 11. Is located in

  The sixth radiation filter unit 21G, the seventh radiation filter unit 21H, and the eighth radiation filter unit 21I each have a sixth radiation absorption characteristic, a seventh radiation absorption characteristic, and an eighth radiation absorption characteristic. The sixth radiation filter unit 21G, the seventh radiation filter unit 21H, and the eighth radiation filter unit 21I selectively absorb and attenuate part of energy components of incident radiation and transmit other components. In the first radiation filter unit 21B to the eighth radiation filter unit 21I, the energy components to be absorbed and the ratio thereof are different from each other.

  The sixth radiation filter unit 21G, the seventh radiation filter unit 21H and the eighth radiation filter unit 21I are also made of Mg, Al, Ti, Fe, Sn, Co, Ni, Cu, Mo, Ag, Ta, W, Pt and Au. And a resin layer in which metal powder of at least one element of at least one element is dispersed. The thickness of the metal plate is, for example, about several hundred μm to several mm.

  In the present embodiment, the sixth radiation filter unit 21G includes a sixth metal plate. The sixth metal plate is formed of one of the above elements, a first metal having a relatively small specific gravity, and a second metal having a relatively large specific gravity. Preferably, the sixth metal plate is made of an element different from the first metal plate, the second metal plate, and the fourth metal plate. The seventh radiation filter unit 21H includes a first metal plate and a sixth metal plate. The eighth radiation filter unit 21I includes a fourth metal plate and a sixth metal plate.

  The sixth metal plates included in the plurality of sixth radiation filter units 21G are connected to each other in the x direction, and are located above the first surface 11a of the ninth scintillator element 11I from the plurality of seventh scintillator elements 11G, y A strip-shaped fourth radiation filter plate 22E extending in the direction is configured. Above the first surface 11 a of the eighth scintillator element 11 H, the first radiation filter plate 22 B and the sixth radiation filter plate 22 G are located in a state of crossing each other. Further, the fourth radiation filter plate 22E and the sixth radiation filter plate 22G are positioned above the first surface 11a of the ninth scintillator element 11I in a cross state. As shown in FIG. 5D, in the present embodiment, the sixth radiation filter plate 22G is formed on the first surface 11a of the eighth scintillator element 11H and the ninth scintillator element 11I in the first radiation filter plate 22B and It is fixed to the fourth radiation filter plate 22E by an adhesive or the like. However, the sixth radiation filter plate 22G may be fixed to the surface 31a of the reflecting member 31, and the first radiation filter plate 22B and the fourth radiation filter plate 22E may be fixed to the sixth radiation filter plate 22G.

  When radiation, eg, X-rays, enter the incident surface 105a of the scintillator array 105, X-rays of the same energy distribution enter the unit cell U, and if attenuation of X-rays at the reflecting member 31 is not taken into consideration, X-rays having the same energy distribution as the X-rays incident on the unit cell U are incident on the first surface 11 a of the scintillator element 11A. On the other hand, from the first surface 11a of the second scintillator element 11B to the first surface 11a of the ninth scintillator element 11I, the first radiation filter portion 21B transmits the eighth radiation filter portion 21I, and a component of a part of the energy band X-rays are attenuated. Therefore, it is possible to simultaneously detect X-rays of different energies by the first scintillator element 11A to the ninth scintillator element 11I.

  In the present embodiment, a unit cell U includes nine scintillator elements 11. A multi-energy scintillator array can be realized by performing image processing with unit cell U as one pixel. Further, as described in the second embodiment, in order to make the number of pixels in the x direction and y direction the same as the number of scintillator elements 11, data may be generated by interpolation in image processing.

  In the present embodiment, the seventh radiation filter portion 21H includes the first metal plate and the sixth metal plate, but a seventh metal plate made of an element different from the first metal plate and the sixth metal plate. May be included. The eighth radiation filter portion 21I includes the fourth metal plate and the sixth metal plate, but includes the eighth metal plate configured of an element different from the fourth metal plate and the sixth metal plate. It is also good. In this case, it is preferable that the first metal plate, the second metal plate, and the sixth metal plate have a rectangular shape not connected to the metal plate on the adjacent scintillator element.

Sixth Embodiment
FIG. 6 (a) is a plan view of the scintillator array 106 of the present embodiment, and FIG. 6 (b) is a cross-sectional view of the scintillator array 106 taken along line 6B-6B of FIG. 6 (a).

  The scintillator array 106 differs from the scintillator arrays 101 to 105 of the first to fifth embodiments in that the scintillator array 106 is provided with a collimator. In this embodiment, an example in which a collimator is provided in the scintillator array 102 of the second embodiment will be described, but a collimator can be similarly provided in the scintillators of the other embodiments.

The scintillator array 106 includes an array portion 41 on the incident surface 106 a side, and a collimator 51 disposed on the reflecting member 31 of the array portion 41. The collimator 51 has an effect of suppressing distortion of the object image due to the radiation or enhancing the resolution by suppressing radiation which is incident obliquely to the first surface 11 a of the scintillator element 11. In the embodiment shown in FIGS. 6A and 6B, radiation incident obliquely to the z axis is blocked or attenuated in the xz plane. The collimator 51 includes a plurality of shielding plates 52 having a predetermined height in the z-axis direction and extending in the y-direction. The shielding plate 52 is disposed between the regions above the first surfaces 11 a of the two adjacent scintillator elements 11 in the x direction.
The first radiation filter plate 22B and the second radiation filter plate 22C are disposed, for example, between the shielding plates 52. The first radiation filter plate 22 </ b> B and the second radiation filter plate 22 </ b> C may be fixed to the shielding plate 52 or may be fixed to the upper surface 41 a of the array unit 41.

  FIG. 7A is a plan view of a scintillator array 106 'according to another embodiment of the present embodiment, and FIG. 7B is a cross-sectional view of the scintillator array 106' taken along line 7B-7B in FIG. 7A. It is. The scintillator array 106 ′ shown in FIGS. 7A and 7B includes an array unit 41 and a collimator 51 ′ disposed on the reflecting member 31 of the array unit 41. The collimator 51 ′ has a grid shape surrounding the upper side of the first surface 11 a of each scintillator element 11. Thereby, the collimator 51 'blocks or attenuates radiation incident obliquely to the z-axis in the xz plane and the yz plane. When the scintillator array 106 ′ includes the collimator 51 ′, the first radiation filter plate 22B and the second radiation filter plate 22C do not have a strip shape, but have a rectangular shape corresponding to a grid. It is preferable to use one radiation filter piece 22B 'and a second radiation filter piece 22C'.

  By providing the collimator 51 ′, it is possible to further suppress distortion of the subject image due to radiation and to improve resolution.

  In the present embodiment, although the embodiments in which the collimators 51 or 51 ′ are provided in the scintillator arrays 101 to 105 according to the first to fifth embodiments have been described, the scintillator arrays 101 to 105 according to the first to fifth embodiments are described. The scintillator array may be configured by providing a collimator with a radiation filter in the array unit 41. That is, as described above, the scintillator array may be configured by the radiation filter attached collimator in which the plurality of radiation filter portions are provided in the collimator 51 or 51 ', and the array portion including the plurality of scintillator elements.

  FIG. 6C shows a plan view of the radiation filter-equipped collimator 110 disposed on the upper surface 41 a which is the incident surface of the array unit 41 including the plurality of scintillator elements 11. FIG. 6 (b) is a cross-sectional view of the scintillator array 106, but also shows the cross section of the radiation filter-equipped collimator 110 disposed in the array section 41. The radiation filter-equipped collimator 110 includes a collimator 51 and a plurality of radiation filter units 21.

  The collimator 51 includes a plurality of shielding plates 52. As described above, the shielding plate 52 has a predetermined height in the z-axis direction, that is, the direction perpendicular to the upper surface 41a (incident surface), and is arranged in one or two dimensions on the upper surface 41a. A plurality of collimating spaces 53 are formed. The collimating space 53 is defined by the shielding plate 52 at least in at least one direction in the xy plane, and the shielding plate 52 absorbs or attenuates radiation that is incident on the collimating space from a direction oblique to the z-axis. When the radiation passes through the collimating space 53, radiation in which the component obliquely incident on the upper surface 41a is reduced is obtained. In the example shown in FIG. 6C, the plurality of collimating spaces 53 have a strip shape extending in the y-axis direction, and are arranged in the x-axis direction. Both ends in the y-axis direction of each shielding plate 52 may be held by a support member (not shown) or the like.

  The plurality of collimating spaces 53 includes a plurality of first collimating spaces 53A, a plurality of second collimating spaces 53B, and a plurality of third collimating spaces 53C. The first collimating space 53A, the second collimating space 53B, and the third collimating space 53C are repeatedly arranged in this order in the x direction.

  The plurality of radiation filter units 21 includes a plurality of first radiation filter units 21B and a plurality of second radiation filter units 21C in the present embodiment. The plurality of first radiation filter units 21B and the plurality of second radiation filter units 21C are respectively disposed in the plurality of second collimating spaces 53B and the plurality of third collimating spaces 53C. Specifically, the plurality of first radiation filter plates 22B and the plurality of second radiation filter plates 22C are respectively disposed in the plurality of second collimating spaces 53B and the plurality of third collimating spaces 53C. The radiation filter portion is not disposed in the plurality of first collimating spaces 53A.

  A first scintillator element 11A, a second scintillator element 11B and a plurality of first collimating spaces 53A, a plurality of second collimating spaces 53B and a plurality of third collimating spaces 53C of the collimator 110 with radiation filter are arranged in the x-axis direction. The scintillator array 106 can be configured by disposing the radiation filter attached collimator 110 on the upper surface 41 a of the array unit 41 so as to coincide with the third scintillator element 11 C.

  FIG. 7 (c) shows a plan view of a radiation filter equipped collimator 111 used in the scintillator array 106 'shown in FIGS. 7 (a) and 7 (b).

  The collimator 51 'comprises a plurality of shielding plates. The plurality of shielding plates constitute a grid in which collimated spaces having a plurality of rectangular shapes are two-dimensionally arranged in the x-axis direction and the y-axis direction. The shielding plates may be arranged in any way as long as they constitute a grid. For example, the collimator 51 ′ includes a plurality of shielding plates 52 extending in the y direction and arranged in the x-axis direction, and a shielding plate 52 ′ disposed between the plurality of shielding plates 52. The shielding plates 52, 52 The grid may be configured by '.

  The shielding plates 52 and 52 'have a predetermined height in the z-axis direction, and have a rectangular shape on the upper surface 41a to form a plurality of two-dimensionally arranged collimating spaces 53.

  In the present embodiment, the plurality of collimating spaces 53 include a plurality of first collimating spaces 53A, a plurality of second collimating spaces 53B, and a plurality of third collimating spaces 53C. The plurality of first collimating spaces 53A, the plurality of second collimating spaces 53B, and the plurality of third collimating spaces 53C are arrayed in a row in the y-axis direction, respectively. The row of collimating spaces 53B and the row of third collimating spaces 53C are arranged in the x-axis direction.

  The plurality of radiation filter units 21 includes a plurality of first radiation filter units 21B and a plurality of second radiation filter units 21C in the present embodiment. The plurality of first radiation filter units 21B and the plurality of second radiation filter units 21C are respectively disposed in the plurality of second collimating spaces 53B and the plurality of third collimating spaces 53C. The radiation filter portion is not disposed in the plurality of first collimating spaces 53A.

  A first scintillator element 11A, a second scintillator element 11B and a plurality of first collimating spaces 53A, a plurality of second collimating spaces 53B and a plurality of third collimating spaces 53C of the collimator 111 with radiation filter are arranged in the y-axis direction. The scintillator array 106 ′ can be configured by arranging the collimator 111 with the radiation filter on the upper surface 41 a of the array unit 41 so as to coincide with the third scintillator element 11 C.

  In the present embodiment, the radiation filter attached collimator 111 adapted to the scintillator array 102 of the second embodiment has been described, but according to the number and arrangement of the scintillator elements constituting the unit cell of the array unit 41, It is possible to realize a radiation-filtered collimator 111 adapted to the scintillator arrays 101 to 105 of the fifth embodiment or scintillator arrays of other configurations.

Seventh Embodiment
FIG. 8A is a plan view of the scintillator array 107 according to this embodiment, and FIG. 8B is a cross-sectional view of the scintillator array 107 taken along line 8B-8B in FIG. 8A. The scintillator array 107 is different from the scintillator array 106 of the sixth embodiment in that a part of the collimator 51 'is embedded in the reflecting member 31 of the array unit 41. Specifically, a part of the shielding plate 52 constituting the collimator 51 ′ is inserted into the groove 41 c provided on the upper surface 41 a of the array unit 41. This structure facilitates alignment between the collimator 51 and the array unit 41.

Eighth Embodiment
Fig.9 (a) is a top view of the radiation detector 108 of this embodiment, FIG.9 (b) is sectional drawing of the radiation detector 108 in the 9B-9B line | wire of FIG. 9 (a). The radiation detector 108 includes the scintillator array of any of the first to seventh embodiments and a plurality of light detection elements. 9 (a) and 9 (b), the radiation detector 108 includes the scintillator array 106 'of the sixth embodiment and a plurality of light detection elements 61. The light detection element 61 is a photoelectric conversion element that converts incident light into an electric signal, and may be, for example, a photodiode such as a silicon photodiode, or may be a photon counter.

  The plurality of light detection elements 61 are disposed to face the second surface 11 b of the scintillator element 11 of the scintillator array 106 ′. For example, so that the second surface 11b of each scintillator element 11 faces and is in contact with the light receiving surface 61a of the light detection element 61, the plurality of light detection elements 61 Are arranged at the same arrangement pitch.

  The radiation detector 108 can simultaneously detect radiation of different energy by converting the fluorescence intensity of each scintillator element of the scintillator array into an electrical signal.

  Further, according to a radiation computed tomography apparatus provided with the radiation detector 108, a radiation source, and a control unit for processing a detection signal output from the radiation detector 108, one type of radiation emitted from the radiation source Even then, radiation transmitted through the subject at different energy bands can be detected simultaneously.

  The arrangement of the first scintillator elements 11A to the ninth scintillator elements 11I in the unit cell U in the above embodiment is an example, and the scintillator elements may be arranged in another arrangement. For example, in the unit direction of the scintillator array 102 of the second embodiment, three scintillator elements are the second scintillator element 11B, the third scintillator element 11C, and the first scintillator element 11A in this order, the third scintillator element 11C, the first scintillator element 11A, the second scintillator element 11B, or the first scintillator element 11A, the third scintillator element 11C, and the second scintillator element 11B, may be arranged in this order. The arrangement of scintillator elements in the y direction is also the same and is not limited to the above embodiment.

(Experimental example)
Using X-rays as radiation, changes in the energy distribution of X-rays due to transmission through a metal plate were investigated. The energy distribution of X-rays transmitted through 1 mm, 3 mm and 5 mm thick Al plates and 1 mm and 3 mm thick Cu plates was determined by simulation using the density and mass absorption coefficient of the elements.

  FIG. 10 shows the result of the Al plate, and FIG. 11 shows the result of the Cu plate. For comparison, the energy distribution of X-rays detected without being transmitted through the metal plate (distribution corresponding to "none" in the figure) is also shown.

  As shown in FIG. 10, the Al plate absorbs and attenuates X-rays, particularly in the energy band of 20 to 60 keV. Further, since the amount of absorption of X-rays varies depending on the thickness of the Al plate, the peak wavelength of X-rays transmitted through the Al plate having different thicknesses is shifted. As shown in FIG. 11, since Cu is an element heavier than Al, it can be seen that the Cu plate absorbs and attenuates X-rays more than the Al plate.

  FIG. 12 shows a simulation result of the energy distribution of X-rays transmitted through the metal plate different in element. A 3 mm thick Al plate, a 1 mm thick Cu plate, a 0.1 mm thick Ta plate and a 3 mm thick Be plate were used. The spectrum of each element shows the relative distribution to the maximum value. For this reason, the intensity of the energy distribution between different elements is not shown correctly. As can be seen from FIG. 12, it can be seen that the energy bands absorbed differ depending on the type of element.

  Therefore, it can be seen that, by using the scintillator array of the present disclosure, it is possible to simultaneously detect energy in the same pixel at different times.

  The scintillator array and radiation detector of the present disclosure can be suitably used in medical and industrial radiography apparatuses.

11 scintillator element 11A first scintillator element 11B second scintillator element 11C third scintillator element 11D fourth scintillator element 11E fifth scintillator element 11F sixth scintillator element 11G seventh scintillator element 11H eighth scintillator element 11I ninth scintillator element 11a ninth scintillator element 11a ninth 1 surface 11 b Second surface 21 Radiation filter unit 21B First radiation filter unit 21C Second radiation filter unit 21D Third radiation filter unit 21E Fourth radiation filter unit 21F Fifth radiation filter unit 21G Sixth radiation filter unit 21H Seventh radiation Filter section 21I eighth radiation filter section 22B first radiation filter plate 22B 'first radiation filter piece 22C second radiation filter plate 22C' second radiation filter piece 22E fourth radiation Ray filter plate 22G sixth radiation filter plate 31 reflecting member 31a surface 41 array portion 41a upper surface 41c groove 51, 51 'collimator 52 shielding plate 53, 53A to 53C collimating space 61 light detecting element 61a light receiving surface 101 to 106, 106', 107 scintillator array 101a to 106a incident surface 108 radiation detector

Claims (22)

A scintillator array comprising a plurality of unit cells arranged in one or two dimensions, the scintillator array comprising:
A plurality of scintillator elements having first and second surfaces opposite to each other;
Equipped with multiple radiation filters,
The plurality of scintillator elements include a plurality of first scintillator elements and a plurality of second scintillator elements,
The plurality of radiation filter units include a plurality of first radiation filter units having a first radiation absorption characteristic,
Each unit cell is
One of the plurality of first scintillator elements and one of the plurality of second scintillator elements;
One of the plurality of first radiation filter units,
Including
In each unit cell, one of the plurality of first radiation filter portions is selectively disposed above the first surface of one of the plurality of second scintillator elements. The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction,
The scintillator array according to claim 1, wherein in each unit cell, one of the plurality of first scintillator elements and one of the plurality of second scintillator elements are arranged in the first direction. The plurality of scintillator elements further include a plurality of third scintillator elements,
The plurality of radiation filter units further include a plurality of second radiation filter units having a second radiation absorption characteristic,
Each unit cell further includes one of the plurality of third scintillator elements and one of the plurality of second radiation filter units,
2. The scintillator according to claim 1, wherein in each unit cell, one of the plurality of second radiation filter portions is selectively disposed above the first surface of one of the plurality of third scintillator elements. array. The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction,
In each unit cell, one of the plurality of first scintillator elements, one of the plurality of second scintillator elements, and one of the plurality of third scintillator elements are arranged in the first direction. The scintillator array according to 3. The plurality of scintillator elements further include a plurality of fourth scintillator elements,
The plurality of radiation filter units further include a plurality of third radiation filter units having a third radiation absorption characteristic,
Each unit cell further includes one of the plurality of fourth scintillator elements and one of the plurality of third radiation filter units,
The scintillator according to claim 3, wherein in each unit cell, one of the plurality of third radiation filter portions is selectively disposed above the first surface of one of the plurality of fourth scintillator elements. array. The plurality of unit cells are two-dimensionally arranged in a first direction and a second direction different from the first direction,
In each unit cell
One of the plurality of first scintillator elements and one of the plurality of second scintillator elements are arranged in the first direction, and
One of the plurality of third scintillator elements and one of the plurality of fourth scintillator elements are arranged in the first direction, and one of the plurality of first scintillator elements and the plurality of second scintillator elements The scintillator array according to claim 5, wherein the scintillator array is adjacent to one in the second direction. The plurality of scintillator elements further include a plurality of fifth scintillator elements and a plurality of sixth scintillator elements,
The plurality of radiation filter units further include a plurality of fourth radiation filter units having a fourth radiation absorption characteristic and a plurality of fifth radiation filter units having a fifth radiation absorption characteristic,
Each unit cell includes one of the plurality of fifth scintillator elements, one of the plurality of sixth scintillator elements, one of the plurality of fourth radiation filter units, and one of the plurality of fifth radiation filter units. Further include
In each unit cell, one of the plurality of fourth radiation filter units and one of the plurality of fifth radiation filter units are located above the plurality of first surfaces of the plurality of fifth scintillator elements, and And 6) selectively disposed above the plurality of first surfaces of one of the sixth scintillator elements,
In each unit cell, one of the plurality of fifth scintillator elements and one of the plurality of sixth scintillator elements are arranged in the second direction, and one of the plurality of fifth scintillator elements and the plurality of The scintillator array according to claim 5, wherein one of the sixth scintillator elements is adjacent to one of the plurality of second scintillator elements and one of the plurality of fourth scintillator elements in the first direction. The plurality of scintillator elements further include a plurality of seventh scintillator elements, a plurality of eighth scintillator elements, and a plurality of ninth scintillator elements.
The plurality of radiation filter units are a plurality of sixth radiation filter units having a sixth radiation absorption characteristic, a plurality of seventh radiation filter units having a seventh radiation absorption characteristic, and a plurality of eighth radiation having an eighth radiation absorption characteristic. Further includes a filter section,
Each unit cell includes one of the plurality of seventh scintillator elements, one of the plurality of eighth scintillator elements, one of the plurality of ninth scintillator elements, and one of the plurality of sixth radiation filter units. And one of the plurality of seventh radiation filter units and one of the plurality of seventh radiation filter units,
In each unit cell, one of the plurality of sixth radiation filter units, one of the plurality of seventh radiation filter units, and one of the plurality of eighth radiation filter units are the plurality of seventh scintillators. Selectively disposed above the first surface of one of the elements, above the first surface of one of the eighth scintillator elements, and above the first surface of one of the ninth scintillator elements. Yes,
In each unit cell, one of the plurality of seventh scintillator elements, one of the plurality of eighth scintillator elements, and one of the plurality of ninth scintillator elements are arranged in the first direction, and And one of the plurality of seventh scintillator elements, one of the plurality of eighth scintillator elements, and one of the plurality of ninth scintillator elements is one or more of the plurality of third scintillator elements. The scintillator array according to claim 7, wherein the scintillator array is adjacent to one of the fourth scintillator elements of claim 1 and one of the plurality of sixth scintillator elements in the second direction, respectively.   Each of the plurality of first radiation filter parts is at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni, Cu, Mo, Ag, Ta, W, Pt and Au. The scintillator array according to any one of claims 1 to 8, comprising a metal plate.   Each of the plurality of first radiation filter portions includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, 9. The scintillator array according to any one of claims 3 to 8, wherein each of the two radiation filter parts comprises a second metal plate consisting of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt and Au. . Each of the plurality of first radiation filter parts includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu,
Each of the plurality of second radiation filter parts includes a second metal plate made of at least one element selected from the group consisting of Mo, Ag, Ta, W, Pt and Au,
Each of the plurality of third radiation filter portions includes a first metal plate made of at least one element selected from the group consisting of Mg, Al, Ti, Fe, Sn, Co, Ni and Cu, Mo, Ag, Ta And a second metal plate made of at least one element selected from the group consisting of W, Pt and Au,
The first metal plates of the plurality of first radiation filter portions and the first metal plates of the plurality of third radiation filter portions are connected to each other in the second direction,
The second metal plate of the plurality of second radiation filter portions and the second metal plate of the plurality of third radiation filter portions are connected to each other in the first direction. The scintillator array described in.   The scintillator array according to any one of claims 1 to 11, further comprising a reflecting member disposed between the plurality of scintillator elements and on the first surface of the plurality of scintillator elements.   The scintillator array of claim 12, further comprising a collimator disposed on the reflective member.   14. The scintillator array of claim 13, wherein a portion of the collimator is inserted into the reflective member.   The scintillator array according to claim 11, wherein the plurality of radiation filter units are provided on the reflection member.   The collimator has a grid shape surrounding an area above the plurality of first surfaces of each scintillator element, and the plurality of radiation filter portions are selectively provided in a part of the grid shape. The scintillator array according to 13 or 14. 17. The scintillator array according to any one of claims 1 to 16,
A plurality of light detection elements disposed to face the second surface of the plurality of scintillator elements of the scintillator array;
Radiation detector with. A radiation source,
A radiation detector according to claim 17;
A radiation computed tomography apparatus, comprising: the radiation source; and a control unit that processes a detection signal output from the radiation detector. A radiation filter-equipped collimator disposed on an incident surface of an array portion including a plurality of scintillator elements arranged in one or two dimensions,
With multiple shields,
Equipped with multiple radiation filters,
The plurality of shielding plates have a predetermined height in a direction perpendicular to the incident surface, and form a plurality of collimated spaces arranged in one or two dimensions on the incident surface,
The plurality of radiation filter units are selectively disposed in at least a part of the plurality of collimate spaces,
The plurality of shielding plates block or attenuate the radiation,
The collimator with a radiation filter, wherein the plurality of radiation filter parts have predetermined radiation absorption characteristics. The plurality of collimated spaces are arranged in a first direction, and each of the plurality of collimated spaces has a strip shape extending in a second direction different from the first direction,
The plurality of collimating spaces include a plurality of first collimating spaces and a plurality of second collimating spaces alternately arranged in the first direction,
The plurality of radiation filter units includes a plurality of first radiation filter units having a first radiation absorption characteristic, and the plurality of first radiation filter units are respectively disposed in the plurality of second collimate spaces. The collimator with a radiation filter according to 19. The plurality of collimating spaces include a plurality of third collimating spaces,
The plurality of radiation filter units include a plurality of second radiation filter units having a second radiation absorption characteristic, and the plurality of second radiation filter units are respectively disposed in the plurality of third collimated spaces. 20. The collimator with radiation filter according to 20. The plurality of collimated spaces are two-dimensionally arranged in a first direction and a second direction different from the first direction, and each of the plurality of collimated spaces has a rectangular shape.
The plurality of collimating spaces include a plurality of first collimating spaces, a plurality of second collimating spaces, a plurality of third collimating spaces, and a plurality of fourth collimating spaces,
The first collimating space, the second collimating space, the third collimating space, and the fourth collimating space are arranged in two rows and two columns adjacent in the first direction and the second direction,
The plurality of radiation filter units include a plurality of first radiation filter units having a first radiation absorption characteristic, a plurality of second radiation filter units having a second radiation absorption characteristic, and a plurality of third radiation having a third radiation absorption characteristic. Including a filter section,
The plurality of first radiation filter units are respectively disposed in the plurality of second collimating spaces,
The plurality of second radiation filter units are respectively disposed in the plurality of third collimate spaces,
20. The radiation filter-equipped collimator according to claim 19, wherein the plurality of third radiation filter units are respectively disposed in the plurality of fourth collimating spaces.

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