JPH08160145A - X-ray detector - Google Patents

Abstract

PURPOSE: To improve the assembling accuracy of an X-ray detector by finely dividing a scintillator in the arranging direction of photodiodes. CONSTITUTION: A photoelectric conversion section 1 is constituted by arranging a plurality of photodiodes 3 two-dimensional on the upper surface of a substrate 2. A collimator 4 is provided above the section 1. The collimator 4 controls the incident direction of X rays and is constituted by arranging a plurality of partition plates in a grid-like state in a frame body. A scintillator 7 which converts X rays passed through the collimator 4 into light is provided between the collimator 4 and section 1. The scintillator 7 is constituted by closely arranging a large number of columnar members 8 composed of CsI, etc., two- dimensionally so that the scintillator 7 can be divided finely by the members 8 in the arranging direction of the photodiodes 3. Therefore, no positional deviation occurs between the photodiodes 3 and scintillator 7 and between the scintillator 7 and collimator 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray detector used in an X-ray CT apparatus or the like.

[0002]

2. Description of the Related Art X-ray C used for obtaining an X-ray tomographic image
The T apparatus includes a bed, an X-ray tube that irradiates a subject on the bed with X-rays, an X-ray detector that is arranged to face the subject with the X-ray tube interposed therebetween, and the X-ray. An X-ray tomographic image is provided which includes a detector and rotary scanning means for rotationally scanning the X-ray tube around the body axis of the subject, and reconstructs the detection signal output from the X-ray detector into image data. Is getting

The X-ray detector of such an X-ray CT apparatus is
The scintillator includes a collimator that controls the incident direction of X-rays, a scintillator that detects the X-rays that have passed through the collimator to generate scintillation light, and a photodiode that converts the scintillation light generated by the scintillator into an electric signal. The scintillation light generated in 1 is detected by a photodiode and a detection signal is output. The collimator, scintillator, and photodiode that form such an X-ray detector are arranged in a one-dimensional direction because the X-rays emitted from the X-ray tube have a fan-shaped spread. A plurality of (for example, 512) detection elements arranged in an array are configured.

[0004]

By the way, in the case of assembling such an X-ray detector, conventionally, a scintillator is superposed on a photodiode, and a collimator is further superposed on the scintillator to assemble the X-ray detector. There is. For this reason, conventionally, it is necessary to assemble the photodiode and the scintillator, and the photodiode + scintillator and the collimator so as not to cause a positional deviation, and it takes a long time to assemble the X-ray detector, and there is a problem that skilled skill is required. there were.

Further, when such an X-ray detector is attached to a rotation frame of an X-ray CT apparatus, an image with high resolution is actually required, so that the center of the detection element constituting the X-ray detector is at the X-axis. The X-ray detector needs to be attached to the rotation frame so as to be offset by 1/4 pitch from the center of the line bundle, which poses a problem that high attachment accuracy is required. The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an X-ray detector capable of improving the assembling accuracy.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 proposes a scintillation light which senses an X-ray passing through the collimator for regulating the incident direction of the X-ray. In the X-ray detector, which has a scintillator that generates a scintillator and a photodiode that converts the scintillation light generated by the scintillator into an electric signal, and arranges these collimator, scintillator and photodiode in at least one-dimensional direction, The scintillator is finely divided in the arrangement direction of the collimator and the photodiode.

According to a second aspect of the present invention, a collimator that regulates the incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and scintillation light that is generated by the scintillator is electrically generated. In a X-ray detector having a photodiode for converting into a signal, and arranging the collimator, the scintillator and the photodiode in at least one-dimensional direction, the photodiode is finely divided in the arrangement direction of the collimator and the scintillator. It is characterized by having done.

According to a third aspect of the present invention, a collimator that regulates an incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and scintillation light that is generated by the scintillator is electrically generated. In a X-ray detector having a photodiode for converting into a signal and arranging the collimator, the scintillator and the photodiode in at least one-dimensional direction, the collimator is finely divided in the arrangement direction of the scintillator and the photodiode. It is characterized by having done.

According to a fourth aspect of the present invention, a collimator that regulates the incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and scintillation light that is generated by this scintillator is electrically generated. An X-ray detector having a photodiode for converting into a signal and arranging the collimator, the scintillator, and the photodiode in at least one-dimensional direction, in which the scintillator and the photodiode are finely divided in the arrangement direction of the collimator. It is characterized by having done.

According to a fifth aspect of the present invention, a collimator for controlling the incident direction of X-rays, a scintillator for sensing the X-rays passing through the collimator to generate scintillation light, and a scintillation light generated by the scintillator are electrically generated. An X-ray detector having a photodiode for converting into a signal and arranging the collimator, the scintillator, and the photodiode in at least a one-dimensional direction, in which the collimator and the scintillator are finely divided in the arrangement direction of the photodiode. It is characterized by having done.

According to a sixth aspect of the present invention, a collimator that regulates the incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and scintillation light that is generated by the scintillator is electrically generated. An X-ray detector having a photodiode for converting into a signal and arranging the collimator, the scintillator, and the photodiode in at least a one-dimensional direction, in which the collimator and the photodiode are finely divided in the arrangement direction of the scintillator. It is characterized by having done.

According to a seventh aspect of the present invention, a collimator for controlling the incident direction of X-rays, a scintillator for detecting the X-rays passing through the collimator to generate scintillation light, and a scintillation light generated by the scintillator are electrically generated. A photodiode for converting into a signal, and an X-ray detector comprising these collimators, scintillators, and photodiodes arranged in at least a one-dimensional direction, wherein the collimators, the scintillators, and the photodiodes are arranged in their arrangement direction. It is characterized by being finely divided. The invention according to claim 8 is
The X-ray detector according to any one of claims 1, 4, 5 and 7 is characterized in that scintillator blocks are laminated in the X-ray incident direction.

[0013]

In the invention according to claim 1, since the scintillator is finely divided in the arrangement direction of the collimator and the photodiode, there is no positional deviation between the photodiode and the scintillator and between the scintillator and the collimator. The X-ray detector can be easily assembled.

According to the second aspect of the present invention, the photodiodes are finely divided in the arrangement direction of the collimator and the scintillator, whereby the accuracy of attachment to the rotation frame can be eased.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.
It will be described with reference to FIGS. In FIGS. 1 and 2, reference numeral 1 denotes a photoelectric conversion unit of an X-ray detector. As shown in FIG. 3, the photoelectric conversion unit 1 has a plurality of photodiodes 3 arranged on a top surface of a substrate 2 in a two-dimensional direction. It is constructed and set up.

A collimator 4 is provided above the photoelectric conversion unit 1. This collimator 4 regulates the incident direction of X-rays, and as shown in FIG. 1, is formed by arranging a plurality of partition plates 6 inside the frame 5 in a grid pattern.

A scintillator 7 for converting the X-rays passing through the collimator 4 into light is provided between the collimator 4 and the photoelectric converter 1. This scintillator 7
As shown in FIG. 4, a plurality of columnar members 8 made of CsI or the like are densely arranged in the two-dimensional direction, and these columnar members 8 subdivide the photodiode 3 in the arrangement direction. (See FIG. 1).

Incidentally, reference numeral 9 in FIG. 1 denotes a reflecting member for reflecting the light from the scintillator 7, and this reflecting member 9 also serves as a supporting member for supporting the scintillator 7. The X-ray detector having such a structure is assembled by adhering and fixing the scintillator 7 to the upper surface of the photoelectric conversion unit 1 and further adhering and fixing the collimator 4 to the upper surface of the scintillator 7. At this time, since the scintillator 7 is subdivided in the arrangement direction of the photodiode 3 by the columnar member 8, there is no displacement between the photodiode 3 and the scintillator 7, and between the scintillator 7 and the collimator 4.

Therefore, according to the first embodiment of the present invention, the X-ray detector can be assembled in a short time without requiring skilled skill. Next, a second embodiment of the present invention will be described with reference to FIGS. In FIG. 5 and FIG. 6, 11 is a collimator that regulates the incident direction of X-rays. As shown in FIG. 6, this collimator 11 has a plurality of partition plates 13 arranged in a grid inside a frame body 12. Is configured.

A scintillator 14 is adhesively fixed to the lower surface of the collimator 11. This scintillator 14
Is for converting X-rays that have passed through the collimator 11 into light. As shown in FIG. 7, a plurality of scintillator members 15 having a size corresponding to the lattice window formed by the partition plate 13 of the collimator 11 are arranged in a two-dimensional direction. The scintillator members 15 are arranged and a light shielding member 16 is provided between the scintillator members 15.

On the lower surface of the scintillator 14, a photoelectric conversion section 17 for photoelectrically converting light from the scintillator 14 is adhered and fixed via an adhesive layer 20. As shown in FIG. 8, the photoelectric conversion unit 17 is configured by arranging a large number of photoelectric conversion elements 19 on a top surface of a substrate 18 in a two-dimensional direction, and these photoelectric conversion elements 19 form the scintillator member 15. It is subdivided in the arrangement direction (see FIG. 5).

The scintillator 14 is a photoelectric conversion element 19
Directly bonded and fixed to. Further, the photoelectric conversion elements 19 are arranged on the upper surface of the substrate 18 all over at an equal pitch, and the judgment of which scintillator 14 the photoelectric conversion elements 19 receive is determined after the detector is mounted on the rotation frame. , X-ray irradiation, and photoelectric conversion element 19
By observing the output of, the shadow from the collimator 11 to another shadow is distinguished as one channel. That is, the output of the photoelectric conversion element 19 in the shadow of the collimator 11 is
Since the output is lower than the output of the other photoelectric conversion elements 19, one channel is provided between the photoelectric conversion elements 19 in the shadow of the collimator 11.

In the X-ray detector having such a structure, the photoelectric conversion section 17 for photoelectrically converting the light from the scintillator 14 is subdivided in the direction in which the scintillator member 15 is arranged by a large number of photoelectric conversion elements 19. 1/4 from the center of the X-ray flux
X-ray CT the X-ray detector so that it is offset by the pitch
High resolution images can be obtained without attaching to the rotation frame of the device.

Therefore, according to the second embodiment of the present invention, the mounting accuracy of the X-ray detector on the rotation frame of the X-ray CT apparatus can be relaxed. Next, a third embodiment of the present invention will be described with reference to FIGS.
Will be described with reference to. In FIGS. 9 and 10, 21
Is a photoelectric conversion unit of the X-ray detector, and this photoelectric conversion unit 21
11, a plurality of photodiodes 23 are two-dimensionally arranged on the upper surface of the substrate 22, as shown in FIG.

A scintillator 24 is adhesively fixed to the upper surface of the photoelectric conversion section 21. This scintillator 24
Is for converting X-rays into light, and as shown in FIG.
A light blocking member 26 is provided between a plurality of scintillator members 25 arranged in the dimensional direction.

On the upper surface of the scintillator 24, a collimator 27 that regulates the incident direction of X-rays is adhered and fixed. As shown in FIG. 10, this collimator 27 is configured by arranging a plurality of partition plates 29 inside the frame 28 in a grid pattern, and these partition plates 29 allow the photodiodes 23 to be arranged in the mounting direction. It is subdivided.

A reference numeral 30 in FIG. 9 is a reflecting member for reflecting the light from the scintillator 24, and this reflecting member 30 also serves as a supporting member for supporting the scintillator 24. In the X-ray detector having such a configuration, the scintillator 24 is bonded and fixed to the upper surface of the photoelectric conversion unit 21, and the scintillator 24 is further attached.
The collimator 27 is bonded and fixed to the upper surface of the assembly. At this time, the collimator 27 is subdivided in the arrangement direction of the photodiodes 23 by the partition plate 29.
There is no displacement between the scintillator 24 and the collimator 27.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 13 and 14. In FIG. 13, reference numeral 1 denotes a photoelectric conversion unit in which a plurality of photodiodes 3 are arranged in a matrix on the upper surface of a substrate 2, and a scintillator 7 and a collimator 4 are provided above the photoelectric conversion unit 1 in the figure. Has been.

The scintillator 7 is constructed by stacking a plurality of scintillator blocks 7a, 7b, 7c, 7d in the X-ray incident direction (vertical direction in the figure). These scintillator blocks 7a, 7b, 7c, 7d are shown in FIG.
As shown in FIG. 4, it is composed of a large number of columnar crystallized CsI8, and when X-rays enter these CsI8, CsI8
The scintillation light is generated from.
In the figure, 30 is an adhesive.

The collimator 4 has a plurality of X-ray entrance windows 4a corresponding to the photodiodes 3, and these X-ray entrance windows 4a regulate the X-ray entrance direction. Reference numeral 9 in the figure denotes a reflecting member that reflects the light from the scintillator 7, and this reflecting member 9 also serves as a supporting member that supports the scintillator 7.

The X-ray detector constructed as described above is assembled by adhering and fixing the scintillator 7 to the upper surface of the photoelectric conversion unit 1 and further adhering and fixing the collimator 4 to the upper surface of the scintillator 7. At this time, the scintillator 7 has a large number of Cs.
Since it is composed of sI8, there is no displacement between the photodiode 3 and the scintillator 7, and between the scintillator 7 and the collimator 4.

Further, when CsI or the like is used for the scintillator 7, at present, a crystal having a sufficient length in the X-ray path direction of the columnar crystal cannot be obtained, so that sufficient X-ray absorption cannot be obtained. Therefore, as shown in FIG.
8 scintillator blocks 7a, 7b, 7c, 7
By stacking d in the incident direction of X-rays to form the scintillator 7, sufficient absorption of X-rays can be obtained.

In each of the above-mentioned embodiments, the X-ray detector in which the photodiodes are arranged in the two-dimensional direction has been described, but it is also applicable to the X-ray detector in which the photodiodes are arranged only in the one-dimensional direction. Is. Further, all of the photoelectric conversion unit, the scintillator and the collimator may be subdivided.

[0034]

As described above, according to the present invention, it is possible to provide the X-ray detector capable of improving the assembling accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an X-ray detector according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an X-ray detector according to the same embodiment.

FIG. 3 is a configuration diagram of a photoelectric conversion unit of the X-ray detector according to the embodiment.

FIG. 4 is a configuration diagram of a scintillator of the X-ray detector according to the embodiment.

FIG. 5 is a sectional view showing a main part of an X-ray detector according to a second embodiment of the present invention.

FIG. 6 is a perspective view of an X-ray detector according to the same embodiment.

FIG. 7 is a configuration diagram of a scintillator of the X-ray detector according to the embodiment.

FIG. 8 is a configuration diagram of a photoelectric conversion unit of the X-ray detector according to the embodiment.

FIG. 9 is a sectional view showing an essential part of an X-ray detector according to a third embodiment of the present invention.

FIG. 10 is a perspective view of the X-ray detector according to the embodiment.

FIG. 11 is a configuration diagram of a photoelectric conversion unit of the X-ray detector according to the embodiment.

FIG. 12 is a configuration diagram of a scintillator of the X-ray detector according to the same embodiment.

FIG. 13 is a sectional view showing an essential part of an X-ray detector according to a fourth embodiment of the present invention.

FIG. 14 is a cross-sectional view showing a configuration of a scintillator block of the same embodiment.

[Explanation of symbols]

 1, 17, 21 ... Photoelectric conversion section 3, 19, 23 ... Photodiode 5, 12, 28 ... Collimator 7, 14, 24 ... Scintillator 7a, 7b, 7c, 7d ... Scintillator block

Claims (8)

[Claims] 1. A collimator for restricting an incident direction of X-rays, a scintillator for detecting the X-rays passing through the collimator to generate scintillation light, and a photodiode for converting the scintillation light generated by the scintillator into an electric signal. And an X-ray detector having these collimators, scintillators, and photodiodes arranged in at least one-dimensional direction, wherein the scintillators are finely divided in the arrangement direction of the collimators and the photodiodes. X-ray detector. 2. A collimator for controlling the incident direction of X-rays, a scintillator for detecting the X-rays passing through the collimator to generate scintillation light, and a photodiode for converting the scintillation light generated by the scintillator into an electric signal. And an X-ray detector in which these collimators, scintillators, and photodiodes are arranged in at least a one-dimensional direction, wherein the photodiodes are finely divided in the arrangement direction of the collimators and the scintillators. X-ray detector. 3. A collimator for controlling the incident direction of X-rays, a scintillator for generating scintillation light by sensing the X-rays passing through the collimator, and a photodiode for converting the scintillation light generated by this scintillator into an electric signal. And an X-ray detector in which these collimators, scintillators, and photodiodes are arranged in at least one-dimensional direction, wherein the collimator is finely divided in the arrangement direction of the scintillators and the photodiodes. X-ray detector. 4. A collimator that regulates the incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and a photodiode that converts the scintillation light generated by the scintillator into an electrical signal. And an X-ray detector having these collimators, scintillators, and photodiodes arranged in at least a one-dimensional direction, wherein the scintillators and the photodiodes are finely divided in the arrangement direction of the collimators. X-ray detector. 5. A collimator that regulates the incident direction of X-rays, a scintillator that senses the X-rays that have passed through the collimator, and generates scintillation light, and a photodiode that converts the scintillation light generated by the scintillator into an electrical signal. And an X-ray detector in which these collimators, scintillators, and photodiodes are arranged in at least a one-dimensional direction, wherein the collimators and the scintillators are finely divided in the arrangement direction of the photodiodes. X-ray detector. 6. A collimator for controlling the incident direction of X-rays, a scintillator for detecting the X-rays passing through the collimator to generate scintillation light, and a photodiode for converting the scintillation light generated by the scintillator into an electric signal. And an X-ray detector in which the collimator, the scintillator, and the photodiode are arranged in at least one-dimensional direction, wherein the collimator and the photodiode are finely divided in the arrangement direction of the scintillator. X-ray detector. 7. A collimator for controlling the incident direction of X-rays, a scintillator for detecting the X-rays passing through the collimator to generate scintillation light, and a photodiode for converting the scintillation light generated by the scintillator into an electric signal. And an X-ray detector having these collimators, scintillators, and photodiodes arranged in at least a one-dimensional direction, wherein the collimator, the scintillators, and the photodiodes are finely divided in their arrangement direction. And an X-ray detector. 8. The X-ray detector according to claim 1, wherein the scintillator blocks are laminated in the X-ray incident direction.