JP2008304349A - Scintillator member and x-ray ct system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scintillator member which efficiently detects a plurality of kinds of X rays whose energy levels are different from each other, can be worked easily, is less deteriorated with X rays, and is suitable for X-ray detectors. <P>SOLUTION: A plurality of scintillator layers 111-113 are arranged in the direction of X-ray transmission, optical transmission members such as a microlens array 120, an optical fiber 130, etc., are provided for each scintillator element 110 constituting the scintillator layers, and light emitted from the scintillator element 110 is transmitted to an optical detection element 140. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a scintillator member and an X-ray CT apparatus, and more particularly to a scintillator member that emits light in response to X-rays and an X-ray CT apparatus having such a scintillator member in an X-ray detector.

2. Description of the Related Art Conventionally, an imaging method for obtaining an image in which a predetermined tissue of a subject is distinguished from other tissues and emphasized is used as an image for examination or diagnosis. As one of such imaging methods, for example, the energy level (energy) of the absorbed X-rays
X-ray imaging or X-ray CT imaging of a subject by combining a plurality of scintillator materials with different levels, and obtaining a plurality of images representing the same subject with different X-ray energies used for depiction. A method of performing a subtraction process or the like is known.

  As a general X-ray detector used for X-ray imaging or X-ray CT imaging, a scintillator layer in which a plurality of scintillator elements are arranged, and a light detection element layer in which a plurality of light detection elements are arranged, A combination of individual scintillator elements and individual photodetector elements so as to correspond to each other is known.

  By the way, the following detectors can be considered as X-ray detectors used when performing the above-described imaging method.

  For example, an X-ray detector in which a plurality of combinations of a scintillator layer in which a plurality of scintillator elements are arranged and a light detection element layer in which a plurality of photodetection elements are arranged in multiple layers is considered (first 1 X-ray detector).

  Further, for example, N types of scintillator layers having different X-ray energy levels absorbed by the scintillator element and wavelengths of light emitted from the element are sequentially stacked to be multilayered, and for each region corresponding to one scintillator element A color filter layer in which N types of color filters (filters) for separating light emission having different wavelengths are provided in a direction perpendicular to the X-ray transmission direction, and a plurality of photodetectors respectively corresponding to the color filters are X-rays An X-ray detector configured by overlapping a light detection element layer provided in a direction perpendicular to the transmission direction is considered (second X-ray detector).

  Further, for example, a plurality of scintillator elements arranged in the X-ray transmission direction and having different energy levels of X-rays to be absorbed, and light detection arranged to face each scintillator element in a direction perpendicular to the X-ray transmission direction For example, Patent Document 1 proposes an X-ray detector in which an X-ray detection element configured by an element is arranged in a direction perpendicular to the X-ray transmission direction (third X-ray detector).

Also, for example, an optical substrate having a structure in which optical fibers are bundled, a needle-like scintillator provided on the optical substrate, which emits light in response to radiation and has a needle-like crystal structure, and the needle-like property A color scintillator having a coating scintillator that coats the scintillator and reacts with radiation having a different energy from the radiation that reacts with the acicular scintillator and emits light with a different color and emission lifetime from the acicular scintillator. color
image sensor (image) having a scintillator), a filter mechanism that sorts light generated by the color scintillator for each wavelength, and a timing adjustment mechanism that adjusts the timing of receiving light (timing).
sensor) is proposed by, for example, Patent Document 2 (fourth X-ray detector).

JP 2001-174564 A JP 2005-106541 A

  However, according to the first X-ray detector, since a general X-ray detector using a scintillator element is simply multi-layered, there is an advantage that manufacturing and assembly are easy. Unlike X-ray detectors of the above, it is necessary to limit the energy level of X-rays absorbed by the upper scintillator element so that X-rays of a predetermined energy level with which the lower scintillator element reacts reach the lower scintillator layer. is there. For this reason, the upper photodetection element is damaged by the X-rays passing through the upper scintillator element and deteriorated and the product life is shortened, or noise (noise) is generated in the output signal of the photodetection element by the X-ray. ) May occur.

  In addition, according to the second X-ray detector, since the light detection element is not damaged and deteriorated by the transmitted X-ray, there is no need to worry about the product life of the light detection element or generation of noise. On the other hand, since a plurality of color filters are provided in an area having a size corresponding to one scintillator element, in each color filter, the amount of emitted light that actually passes out of emitted light having a passable wavelength is Since the amount of light is reduced in accordance with the area of the color filter, there is a problem that the light emission detection efficiency is deteriorated, and as a result, the X-ray detection efficiency is deteriorated.

  In addition, according to the third X-ray detector, the problems with the first and second X-ray detection elements are solved, but with a structure in which the light detection element is sandwiched between scintillator elements (cells). Therefore, high processing accuracy is required, and it is expected that problems in manufacturing and assembly, such as technical difficulties, problems such as an increase in man-hours and manufacturing costs (cost), and the like will occur.

  Further, according to the fourth X-ray detector, the problems with the first and second X-ray detection elements are solved, but the X-ray detection efficiency is reduced because the filter mechanism is provided. That is expected.

  In view of the above circumstances, the present invention efficiently detects a plurality of types of X-rays having different energy levels, is relatively easy to process, and has little deterioration due to X-rays, and such a scintillator member It is an object to provide an X-ray CT apparatus having an X-ray detector.

  In a first aspect, the present invention provides a plurality of scintillator layers in which a plurality of scintillator layers arranged in a direction perpendicular to the X-ray transmission direction are arranged in the X-ray transmission direction, and the scintillator. There is provided a scintillator member comprising a plurality of light transmission members each provided with a light transmission member for transmitting light emitted from the element for each of the scintillator elements.

  In a second aspect, the present invention provides the scintillator member according to the first aspect, wherein the scintillator layer has a large number of scintillator elements arranged in a matrix.

  In a third aspect, the present invention provides a light transmission layer in which a plurality of light transmission members provided in a plurality of scintillator elements constituting one scintillator layer are parallel to the scintillator layer for each of the plurality of scintillator layers. The scintillator member according to the first aspect or the second aspect is provided. The light transmission member has X-ray transparency.

  In a fourth aspect, the present invention provides the scintillator member according to the third aspect, wherein the scintillator layer and the light transmission layer are alternately arranged in the X-ray transmission direction.

  In a fifth aspect, the present invention provides the scintillator member according to any one of the first to third aspects, wherein the light transmission member includes a lens or an optical fiber.

  In a sixth aspect, the present invention is the first aspect, further comprising a plurality of light detection elements each provided with a light detection element that detects light emitted from the scintillator element by the light transmission member for each of the scintillator elements. A scintillator member according to any one of the fifth aspects is provided.

  In a seventh aspect, the present invention provides the scintillator member according to the sixth aspect, wherein the plurality of photodetecting elements are arranged along a plane parallel to the X-ray transmission direction.

In an eighth aspect, the present invention is based on projection data of a plurality of views obtained by scanning an imaging target with an X-ray using an X-ray source and an X-ray detector having a scintillator member. X-ray CT (Computed)
A plurality of scintillator layers in which a plurality of scintillator layers in which the scintillator members are arranged in a direction perpendicular to the X-ray transmission direction are arranged in the X-ray transmission direction; Provided is an X-ray CT apparatus comprising a plurality of light transmission members each provided with a light transmission member for transmitting light emitted from the scintillator elements for each of the scintillator elements.

  According to the scintillator member of the present invention, a plurality of scintillator elements are arranged in the X-ray transmission direction, and each scintillator element is provided with a light transmission member that transmits light emitted from the element. Detection efficiency does not decrease, X-rays are directly irradiated to the light detection element, do not suffer damage or generate unnecessary signal noise, and are composed of members having a relatively general shape It can be. As a result, it is possible to efficiently detect a plurality of types of X-rays having different energy levels, realize a scintillator member that is relatively easy to process and has little deterioration due to X-rays. In addition, an X-ray CT apparatus having such a scintillator member in the X-ray detector can be realized.

  The best mode for carrying out the invention will be described below with reference to the drawings. Note that the present invention is not limited to the best mode for carrying out the invention.

  FIG. 1 is a block diagram of an X-ray CT apparatus. This apparatus is an example of the best mode for carrying out the present invention. An example of the best mode for carrying out the present invention relating to an X-ray CT apparatus is shown by the configuration of the apparatus. An example of the best mode for carrying out the present invention relating to the scintillator member is shown by a part of the configuration of the present apparatus.

As shown in FIG. 1, the apparatus includes a scanning gantry 2, an imaging table 4, and an operation console 6. The scanning gantry 2 has an X-ray tube 20. X-rays (not shown) emitted from the X-ray tube 20 are collimated by a collimator 22 to form a fan-shaped X-ray beam, ie, a fan beam (fan).
beam) The X-ray detector 24 is irradiated with the X-ray detector 24 after being shaped (collimation). The X-ray detector 24 has a large number of X-ray light conversion elements arranged in an array in accordance with the spread of the X-ray beam. The configuration of the X-ray detector 24 will be described later.

  In the space between the X-ray tube 20 and the X-ray detector 24, an imaging target is mounted on the imaging table 4 and carried in. The X-ray tube 20, the collimator 22, and the X-ray detector 24 constitute an X-ray irradiation / detection device. The X-ray irradiation / detection apparatus will be described later.

A data collection unit 26 is connected to the X-ray detector 24. The data collection unit 26 outputs detection signals corresponding to individual X-ray light conversion elements of the X-ray detector 24 to digital data (digital).
data). The detection signal corresponding to the X-ray light conversion element is a signal representing the projection of the object to be imaged by X-rays. Hereinafter, this is also referred to as projection data or simply data.

X-ray irradiation from the X-ray tube 20 is controlled by an X-ray controller 28. The connection relationship between the X-ray tube 20 and the X-ray controller 28 is not shown. The collimator 22 is a collimator controller (collimator).
controller 30). The connection relationship between the collimator 22 and the collimator controller 30 is not shown.

  The components from the X-ray tube 20 to the collimator controller 30 described above are mounted on the rotating unit 34 of the scanning gantry 2. The rotation of the rotating unit 34 is controlled by the rotation controller 36. The connection relationship between the rotating unit 34 and the rotation controller 36 is not shown.

  The operation console 6 has a data processing device 60. The data processing device 60 is configured by, for example, a computer. A control interface (interface) 62 is connected to the data processing device 60. The control gantry 2 and the imaging table 4 are connected to the control interface 62. The data processing device 60 controls the scanning gantry 2 and the imaging table 4 through the control interface 62.

  The data acquisition unit 26, the X-ray controller 28, the collimator controller 30, and the rotation controller 36 in the scanning gantry 2 are controlled through the control interface 62. Note that illustration of individual connections between these units and the control interface 62 is omitted.

  A data collection buffer 64 is connected to the data processing device 60. A data collection unit 26 of the scanning gantry 2 is connected to the data collection buffer 64. Data collected by the data collection unit 26 is input to the data processing device 60 through the data collection buffer 64.

  A storage device 66 is connected to the data processing device 60. The storage device 66 stores projection data input to the data processing device 60 through the data collection buffer 64 and the control interface 62, respectively. The storage device 66 also stores a program for the data processing device 60. When the data processing device 60 executes the program, the operation of this device is performed.

The data processing device 60 performs image reconstruction using the projection data collected in the storage device 66 through the data collection buffer 64. For image reconstruction, for example, filtered back projection (filtered back projection)
back projection) method or the like is used.

A display device 68 and an operation device 70 are connected to the data processing device 60. The display device 68 is configured by a graphic display or the like. The operation device 70 is a pointing device.
device) and a keyboard.

  The display device 68 displays the reconstructed image and other information output from the data processing device 60. The operation device 70 is operated by a user and inputs various instructions and information to the data processing device 60. The user operates the present apparatus interactively using the display device 68 and the operation device 70.

  FIG. 2 is a diagram showing a schematic configuration of the X-ray detector 24. As shown in the figure, the X-ray detector 24 is a multi-channel X-ray detector in which a large number of X-ray light conversion elements 24 (ik) are arranged in a two-dimensional matrix. The X-ray detector 24 as a whole forms an X-ray detection surface curved in a cylindrical concave shape. The X-ray detector 24 is not limited to a two-dimensional array, and may be a one-dimensional array.

  Here, i is a channel number, for example, i = 1, 2,. k is a column number, for example, k = 1, 2,. The X-ray light conversion elements 24 (ik) each have the same column number k and constitute a light conversion element array. In addition, the light conversion element row | line | column of the X-ray detector 24 is not restricted to 16 row | line | columns, The appropriate plural or single may be sufficient.

  FIG. 3 is a diagram showing the interrelationship among the X-ray tube 20, the collimator 22, and the X-ray detector 24 in the X-ray irradiation / detection apparatus. 3A is a diagram showing a state seen from the front of the scanning gantry 2, and FIG. 3B is a diagram showing a state seen from the side. As shown in the figure, the X-rays emitted from the X-ray tube 20 are shaped by the collimator 22 into a fan-shaped X-ray beam 400 and irradiated to the X-ray detector 24.

  FIG. 3A shows the spread of the fan-shaped X-ray beam 400 in one direction. Hereinafter, this direction is also referred to as a width direction. The width direction of the X-ray beam 400 coincides with the channel arrangement direction in the X-ray detector 24. (B) shows the expansion of the X-ray beam 400 in the other direction. Hereinafter, this direction is also referred to as a thickness direction of the X-ray beam 400. The thickness direction of the X-ray beam 400 coincides with the parallel arrangement direction of the plurality of X-ray light conversion element arrays in the X-ray detector 24. The two spreading directions of the X-ray beam 400 are perpendicular to each other.

  FIG. 4 is a diagram illustrating a relationship between the X-ray irradiation / detection apparatus and the imaging target 8. For example, as shown in FIG. 4, the imaging object 8 placed on the imaging table 4 is carried into the X-ray irradiation space with the body axis intersecting the X-ray beam 400 as described above. The scanning gantry 2 has a cylindrical structure including an X-ray irradiation / detection device inside.

  The X-ray irradiation space is formed in the inner space of the cylindrical structure of the scanning gantry 2. An image of the imaging target 8 sliced by the X-ray beam 400 is projected onto the X-ray detector 24. The X-ray detector 24 detects X-rays transmitted through the imaging target 8 for each X-ray light conversion element array. The thickness th of the X-ray beam 400 irradiated to the imaging object 8 is adjusted by the opening degree of the aperture of the collimator 22.

In parallel with the rotation of the X-ray irradiation / detection device, the X-ray irradiation / detection device performs relative imaging with respect to the imaging target 8 by continuously moving the imaging table 4 in the body axis direction of the imaging target 8. It will turn along a spiral trajectory surrounding the object 8. As a result, the so-called helical scan (helical scan)
scan) is performed. If the X-ray irradiation / detection device is rotated while the imaging table 4 is stopped, an axial scan is performed.

  Projection data of a plurality of views (for example, about 1000) per scan rotation is collected. The projection data is collected by a series of X-ray detector 24 -data collection unit 26 -data collection buffer 64. Image reconstruction is performed by the data processing device 60 based on the projection data collected in this way.

  Here, the configuration of the X-ray detector 24 will be described in detail. The X-ray detection surface of the X-ray detector 24 has a scintillator member in which a predetermined number of X-ray light conversion elements 24 (ik) are developed in the i direction and the k direction as one module. It is configured by connecting multiple directions. Note that the X-ray detection surface of the X-ray detector 24 may be formed of a single scintillator member.

FIG. 5 is a diagram showing a schematic configuration of a main part of the X-ray detector 24 for one module. In the figure, when i, j, and k are three directions perpendicular to each other, i is a direction parallel to a row of the two-dimensional matrix. k is a direction parallel to the columns of the two-dimensional matrix. j is the direction in which the X-ray beam arrives, that is, the X-ray transmission direction. 5A is a cross-sectional view when one scintillator member 100 is viewed in the i direction, and FIG. 5B is a perspective view of one scintillator member 100 seen from the j direction. Lens array (micro
(lens array) layer 121 is a view, and (c) is a view when scintillator member 100 is seen through from the j direction and optical fiber group 131 as a component is viewed.

  As shown in the figure, the scintillator member 100 has a plurality of scintillator layers 111 to 113. Each scintillator layer is configured by arranging a plurality of scintillator elements 110 that absorb X-rays and emit light in a two-dimensional matrix. The scintillator layers 111 to 113 are arranged substantially parallel to the ik plane with a predetermined interval in the j direction. Further, each scintillator element 110 constituting the scintillator layer is aligned so that the region overlaps between the scintillator layers 111 to 113 when viewed in the j direction, and the channel number i and the column number k are the same. A combination of three scintillator elements overlapping in the j direction corresponds to the X-ray light conversion element 24 (ik). The scintillator element 110 is molded with a light reflective material except for the light exit surface. Here, although the number of scintillator layers is three here, the number is not limited thereto.

  The scintillator member 100 also has a plurality of microlens array layers 121-123. The microlens array layer is formed by arranging a plurality of macrolens arrays 120 made of a material having X-ray transparency such as glass or plastic, in a matrix. In the microlens array 120, the light incident surface 120a is arranged on the light emitting surface 110b side of the scintillator element 110 constituting the scintillator layer, and the light emitted from the scintillator element 110 is condensed on the light emitting unit 120b. Here, the scintillator element 110 has a light emitting surface 110b in the j direction, that is, the X-ray transmission direction, and the microlens array 120 has a light incident surface 120a disposed at a position facing the light emitting surface 110b. One microlens array 120 is provided for each scintillator element 110. The microlens array layers 121 to 123 correspond to the scintillator layers 111 to 113, respectively.

  The scintillator member 100 also has a plurality of optical fiber groups 131 to 133. The optical fiber group is composed of a plurality of optical fibers 130 made of a material having X-ray transparency such as glass and plastic. The optical fiber 130 is mainly arranged to extend in, for example, the k direction along a plane parallel to the ik plane, and the light incident portion 130a that is one end of the optical fiber 130 is a microlens that constitutes a microlens array layer. It is optically coupled to the light emitting portion 120b of the array 120. Instead of the microlens array, a light reflection plate or the like may be used to guide light emitted from the scintillator element 110 to the light incident portion 130a of the optical fiber 130. Alternatively, instead of the microlens array, a light reflector that surrounds the entire inner surface with a light reflecting plate except for a predetermined opening, that is, an opening through which light emitted from the scintillator element 110 is incident and an opening through which the light is emitted is provided. You may make it connect the light-incidence part 130a of an optical fiber to the opening part for light emission emission of the light reflector. The light emitting part 130 b of the optical fiber 130 is collected on one side of the scintillator member 100. The optical fiber groups 131 to 133 correspond to the microlens array layer groups 121 to 123, respectively.

  The scintillator layer, the microlens array layer, and the optical fiber group are alternately arranged on the base 150 in this order in the j direction, that is, the X-ray transmission direction. One light transmission layer is formed.

  The scintillator member 100 also has a plurality of light detection element groups 141 to 143. Each photodetecting element group includes a plurality of photodetecting elements 140 that detect light and convert it into an electrical signal. The light detection element 140 is arranged with the light receiving surface 140a facing the light emitting portion 130b side of the optical fiber 130. One photodetecting element 140 is provided for each scintillator element 110. The light detection element group is surrounded by an X-ray absorbing member such as tungsten or molybdenum and is provided in a non-irradiated region of the X-ray beam, and is parallel to the j direction, that is, the X-ray transmission direction. Arranged along the surface. The photodetecting element groups 141 to 143 correspond to the scintillator layers 111 to 113, respectively.

As described above, the X-ray detector 24 is configured by a combination of a plurality of scintillator layers, a plurality of microlens array layers, a plurality of optical fiber groups, and a plurality of photodetector elements, and the scintillator elements of each scintillator layer The light emitted by absorbing X-rays is transmitted by the microlens array and the optical fiber, detected by the light detection element, and converted into an electrical signal. As the scintillator element 110, for example, cesium iodide (Cs) is used, but is not limited thereto. Further, as the light detection element 140, for example, a photodiode (photo)
diode) is used, but is not limited to this.

  In the X-ray detector 24 having such a configuration, since the multicolor X-rays pass through the plurality of scintillator elements 110 in series, the X-rays that cause scintillation in each scintillator element 110 due to the energy dependency of the X-ray attenuation coefficient are Each energy distribution will be different. That is, the plurality of scintillator elements 110 absorb X-rays having different energy levels.

  For example, when the energy distribution of X-rays irradiated to the most upstream scintillator element of X-ray transmission is as shown by e1 in FIG. 6, the energy distribution of X-rays irradiated to the next scintillator element is By reducing the low-energy photons, e.g., e2, and the X-rays irradiated to the scintillator element located next to the photon are further reduced by e.g. e3. The energy distribution is as follows.

  The difference between e1 and e2 corresponds to the amount absorbed by the first scintillator element. The difference between e2 and e3 corresponds to the absorption by the next scintillator element. e3 corresponds to the absorption by the last scintillator element. That is, as the depth of transmission of X-rays increases, relatively low energy photons decrease and high energy photons remain, so-called X-ray quality hardening occurs.

  Signals obtained by detecting such X-rays having different radiation qualities, that is, X-rays having different energy distribution regions, are obtained through the photodetectors 140 of the corresponding system. Therefore, tomographic images having different clinical significance can be obtained by reconstructing images based on the X-ray detection signals of the respective systems.

  An X-ray detection signal containing a large amount of low energy components is suitable, for example, for reconstructing a fat image. An X-ray detection signal containing a lot of high energy components is suitable for reconstructing a bone density image, for example. Note that the X-ray detection signal having a moderate energy distribution is suitable for reconstructing a general-purpose image.

  The photographing operation of this apparatus will be described. FIG. 8 is a flowchart of the operation of this apparatus. As shown in the figure, in step 912, the operator inputs a scan plan through the operation device 70. The scan plan includes the number of images reconstructed from the data of one scan in addition to the scan time, scan range, X-ray irradiation conditions, and the like.

  The scan plan is input by, for example, an input screen displayed on the display device 68. For example, a GUI simulating three push buttons is displayed on the input screen for specifying the number of images. The three push buttons display numbers representing the number of images on each surface.

  The number 1 means obtaining one image. This also means that the tomographic images for 4 slices are all added and averaged. The number 2 means obtaining two images. This also means that four slices of tomographic images are averaged by two adjacent slices. The number 4 means that four images are obtained. This also means that four slices of tomographic images are individually imaged. The operator designates a desired number using a pointing device or the like.

  This apparatus operates under the operation of the operator and control by the data processing apparatus 60 in accordance with the input scan plan. In step 914, scan positioning is performed. That is, the operator operates the operation device 70 to move the imaging table 4 so that the center of the imaging region of the imaging object 8 coincides with the rotation center (isocenter) of the X-ray irradiation / detection device.

  After such scan positioning is performed, scanning is performed in step 916. That is, the X-ray irradiation / detection device is rotated around the imaging target 8 and, for example, 1000 views of projection data per rotation are collected in the data collection buffer 64.

  Data correction is performed in step 918 after scanning or in parallel with scanning. Data correction includes, for example, X-ray intensity correction, channel sensitivity correction, temperature correction, and the like. As a result, corrected data for four slices is obtained for a plurality of systems having different X-ray quality.

  In step 920, the addition average corresponding to the number of designated images is performed on the data of four slices of the plurality of systems. That is, for each system, when the number of designated images is 1, the data for four slices is totaled and averaged. When it is 2, half the data is averaged and when it is 4, the averaging is not performed.

  Based on the addition averaged data, image reconstruction is performed for each system in step 922. Image reconstruction is performed by, for example, a filtered back projection method. Thereby, a tomographic image is reconstructed. Of course, the addition averaging may be performed on the reconstructed image instead of being performed in step 918.

  Next, in step 924, an image is displayed. As a result, for each system, for example, an image as shown in FIG. (A) of the figure is a case where the number of images is 1, (b) is a case where the number of images is 2, and (c) is a case where the number of images is 4.

  Thereby, for example, a fat image and a bone density image can be obtained in one scan in addition to the general-purpose image.

  According to this embodiment, a plurality of scintillator elements 110 are arranged in the X-ray transmission direction, and the microlens array 120 and the optical fiber 130 that transmit light emitted from the elements are provided for each scintillator element 110. Therefore, the detection efficiency of light emission from the scintillator element 110 does not decrease, the X-rays are not directly irradiated on the light detection element 140, and no damage or generation of unnecessary signal noise occurs. It can be set as the structure comprised from a member of a typical shape. As a result, it is possible to efficiently detect a plurality of types of X-rays having different energy levels, realize a scintillator member that is relatively easy to process and has little deterioration due to X-rays. Further, an X-ray CT apparatus having such a scintillator member in the X-ray detector 24 can be realized.

  In addition, according to the present embodiment, since the processing is easy as described above, the scintillator layer can be easily multi-layered, and the multi-layer is not limited to two or three layers as long as the characteristics of the scintillator element allow. Is possible.

  In addition, according to the present embodiment, since the plurality of light detection elements are arranged along the plane parallel to the j direction, that is, the X-ray transmission direction, the light detection elements can be made difficult to receive. Deterioration and electrical noise from the light detection element can be suppressed.

  In this embodiment, a combination of a microlens array and an optical fiber is used as a light transmission member that transmits light emitted from the scintillator element to the light detection element, but is not limited thereto. For example, an optical substrate in which an optical fiber or another optical waveguide is incorporated into the substrate may be used as all or part of the light transmission member. For example, an optical fiber having a specially processed end that functions like a microlens array may be used as the light transmission member.

  In this embodiment, the energy level of the X-rays that each scintillator layer reacts with changes in the energy distribution of the X-rays incident on the next scintillator layer due to X-ray absorption in the upper scintillator layer, Although the case where the energy level of the absorbed X-ray is changed has been described, the energy level of the X-ray absorbed by each scintillator layer may be originally different, for example, high, medium, and low.

It is a block diagram of an apparatus which is an example of an embodiment of the invention. It is a schematic diagram of the detector array in the apparatus shown in FIG. It is a schematic diagram of the X-ray irradiation / detection apparatus in the apparatus shown in FIG. It is a schematic diagram of the X-ray irradiation / detection apparatus in the apparatus shown in FIG. It is a schematic diagram of the principal part of a detector array. It is a figure which shows the energy distribution of a polychromatic X-ray. It is a flowchart of operation | movement of the apparatus shown in FIG. It is a schematic diagram of the image which the apparatus shown in FIG. 1 displays.

Explanation of symbols

2 Scanning gantry 6 Operation console 8 Imaging object 20 X-ray tube 22 Collimator 24 X-ray detector 24 (ik) X-ray light conversion element 26 Data collection unit 28 X-ray controller 30 Collimator controller 34 Rotation unit 36 Rotation controller 36 Data processing device 62 control interface 64 data collection buffer 66 storage device 68 display device 70 operation device 100 scintillator member 110 scintillator element 111,112,113 scintillator layer 120 microlens array 121,122,123 microlens array layer 130 optical fiber 131,132,133 Optical fiber group 140 Photodetection element 141, 142, 143 Photodetection element group 400 X-ray beam

Claims (8)

A plurality of scintillator layers formed by arranging a plurality of scintillator layers in the X-ray transmission direction by arranging a plurality of scintillator elements in a direction perpendicular to the X-ray transmission direction;
A scintillator member comprising: a plurality of light transmission members each provided with a light transmission member for transmitting light emitted from the scintillator elements for each of the scintillator elements.   The scintillator member according to claim 1, wherein the scintillator layer includes a large number of scintillator elements arranged in a matrix.   The plurality of light transmission members provided in a plurality of scintillator elements constituting one scintillator layer form a light transmission layer parallel to the scintillator layer for each of the plurality of scintillator layers. The scintillator member according to 1.   The scintillator member according to claim 3, wherein the scintillator layer and the light transmission layer are alternately arranged in the X-ray transmission direction.   The scintillator member according to any one of claims 1 to 3, wherein the light transmission member includes a lens or an optical fiber.   6. The apparatus according to claim 1, further comprising a plurality of light detection elements each provided with a light detection element that detects light emission transmitted from the scintillator element by the light transmission member for each of the scintillator elements. The scintillator member according to 1.   The scintillator member according to claim 6, wherein the plurality of light detection elements are arranged along a plane parallel to the X-ray transmission direction. An X-ray CT apparatus for reconstructing an image based on projection data of a plurality of views obtained by scanning an imaging target with an X-ray using an X-ray source and an X-ray detector having a scintillator member,
The scintillator member is
A plurality of scintillator layers formed by arranging a plurality of scintillator layers in the X-ray transmission direction by arranging a plurality of scintillator elements in a direction perpendicular to the X-ray transmission direction;
An X-ray CT apparatus comprising: a plurality of light transmission members each provided with a light transmission member that transmits light emitted from the scintillator elements for each of the scintillator elements.

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