JPH10314157A - X-ray detector and x-ray ct device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate aberration of a detecting element array and a collimator array by inserting one tip of a collimator plate into a groove provided at a scintillator material and inserting the side part of a collimator plate into a vertical groove equivalent to a channel interval provided at the side face of a holding plate. SOLUTION: The detecting element array 1 of the detecting module of an X-ray detector for a CT device is fixed to the polygon faces of module members 2a and 2b and arranges the collimator array 3 between the members 2a and 2b. The array 3 consists of the collimator plate 5 over a detecting part and holding plates 6a and 6b, and an X-ray detecting element 7 obtained by composing a scintillator and a photoelectric tranceducer is arranged on the substrate of the array 1. A part of the plate 5 is fit into a gap (groove) between the channels of the element 7 on the substrate of the array 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray detector capable of reducing image deterioration due to X-rays scattered by a subject and performing more accurate measurement, and an X-ray detector using the same. The present invention relates to a line CT apparatus.

[0002]

2. Description of the Related Art A detection element of an X-ray CT apparatus measures attenuation of a part of a subject on a line (measurement path) connecting a focus of an X-ray tube and the center of the detection element. Scattered X-rays cause an error in the measurement. When the scattered X-rays are incident, the output of the detection element is increased, and the measurement is performed so that the attenuation of the subject on the measurement path is apparently reduced. When such errors increase, the resolution of a CT image reconstructed using these data decreases. In particular, there is a problem in that a low contrast resolution called a density resolution is lowered. In addition, the CT value inside the ossicle, which is clinically called rib artifact, sinks and a black area appears on the image, or C in the liver.
Phenomena such as the T value varying from place to place occur.

FIG. 23 shows a schematic configuration of an ionization chamber detector which is a kind of an X-ray detector. A high voltage electrode plate 41 and a signal electrode plate 42 are alternately arranged in parallel, and a high voltage electrode plate 41 and a signal electrode plate are arranged. An ionization space 48 that contributes to the detection output is formed between the two. This ionization chamber detector has electrode plates 41, 4
2 has a certain collimator effect, and the sensitivity of the X-rays 44 incident obliquely is much lower than the sensitivity of the X-rays 43 incident from the X-ray tube (source of X-ray) focal point.

FIG. 24 shows a schematic configuration of a solid state detector which is a kind of an X-ray detector. A scintillator 45, a photoelectric conversion element 46 (hereinafter referred to as a detection element) disposed at the rear end thereof, and a scintillator It is composed of a partition plate 47 that partitions between 45. Since this solid state detector has no collimator effect, the channel width of the X-rays 44 incident obliquely is smaller than the channel width of the X-rays 43 incident from the focal point of the X-ray tube. Therefore, there is not much difference in sensitivity between the X-ray 43 incident from the X-ray tube focal direction and the X-ray 44 incident obliquely. Therefore, even at the level of scattered radiation that was not a significant problem as an image artifact in the ionization chamber detector,
Solid-state detectors often suffer from image quality degradation.

[0005] The above problems in the solid state detector can be solved by disposing a channel direction collimator plate at the detector incidence part. Specifically, as shown in FIG.
It is solved by providing. The partition plate 47 can prevent the emission and scattering of the incident X-rays from the scintillator from entering the adjacent channel and causing crosstalk. Note that the element boundary portion partitioned by the partition plate 47 has no sensitivity to incident X-rays in terms of configuration.

The incoming X-rays are absorbed by the partition plate 47 (collimator plate in the channel direction) and do not reach the rear. Therefore, in consideration of the efficiency of use of incident X-rays, it is desirable to dispose a collimator plate (not shown) at the boundary of the detection element where the detection element has no sensitivity. When the collimator plate is arranged at the boundary of the detection element where the detection element has no sensitivity, if the alignment accuracy is poor, the incident X-rays may cast a shadow of the partition plate 47 on the sensitive part of the detection element. Become. This effect degrades the uniformity of the output between channels or within a channel, and eventually causes artifacts in the obtained image.

As described above, the partition plate 47 is provided on the front surface of the detecting element.
Is installed, its alignment accuracy affects the performance of the entire detector. In particular, the alignment accuracy of the collimator
Even if there is a slight displacement (about 0.5 mm) in the slice direction, the characteristics of the detection element hardly change, but it is necessary to be strict in the channel direction.

However, when positioning the collimator plate in which the detection element array arranged in a polygonal shape and all the channels are integrally assembled, in some channels where the channel pitches of both channels are not uniform over all the channels of the detector. Although the positioning is optimally performed, the other channels are misaligned. In order to ensure a uniform channel pitch over all channels, the alignment when assembling the detector element array in a polygonal shape is highly accurate in one place if the cumulative error in all channels is to be suppressed. There is a need to do.

However, when the number of detection element arrays is about 40 to 50, if it is attempted to reduce the total positional deviation to 50 μm or less, it must be assembled at 1 μm or less per location, which is extremely difficult.

As described above, a problem arises when the alignment of the detection element array and the collimator array are separately assembled and then aligned. For example, USP
As shown in US Pat. No. 4,338,521, when the detection element array and the collimator array in the channel direction are accurately matched, a positioning pin is provided on the detection element array.
There is a mounting method in which a collimator array is combined based on these pins. However, in this method, the shapes of the detection element array and the collimator array are complicated, the man-hour is required, and the number of channels of the detection element array and the collimator array must be the same.

The size of the detection element array is limited by the size of the detection conversion element. The photodiode, which is a representative of the detection element, is made of silicon, and its size is determined according to the wafer size used. If the size of the light receiving element array is within the size of the light receiving element array, it is possible to increase the size. However, if the size of the light receiving element array is increased, the number of element arrays that can be manufactured from one silicon wafer decreases, and accordingly, the silicon wafer Utilization rate is reduced and becomes expensive. At present, as a practical dimension range, one side of the light receiving element array is about 20 to 30 mm.

Even if a large-area light-receiving element array can be used, when the detection element array is arranged in a polygon in the container, if the length of one side of the polygon is increased, the arcs are approximated and arranged. The displacement on the polygon surface becomes large, which causes image artifacts due to measurement errors. For this reason, the size of one side of the polygon is limited to about 30 mm at a radius of about 1000 mm of the standard detection element array of the current CT apparatus.

On the other hand, the size of the collimator array is not limited by the used portion. In addition, since the collimator plates are arranged on an arc, there is no problem of misalignment when the detection element array is arranged in a polygonal shape. For this reason, for the collimator array, it is advantageous to increase the size of the collimator array within a range in which processing and assembly are easy, for the purpose of manufacturing with high accuracy and low cost. Furthermore, when the collimator array is arranged in a container by increasing the size of the collimator array, the number of connecting portions between the collimator arrays requiring relative positional accuracy is reduced, and the assembly is facilitated.

[0014]

However, according to the conventional X-ray detector for a CT apparatus, in order to secure the relative positional accuracy between the detection element array and the collimator array, the reference pins and the reference pins are fitted to the detection element array and the collimator array. When the holes are fitted and assembled, it is necessary to match both with the smaller inner dimensions of each detection element array, and the collimator array must be reduced to about 30 mm inevitably. However, there is a problem that the number of steps increases.

As a method of aligning the X-ray detection element and the collimator plate, a method of extending the partition plate 47 inserted into the channel separation gab of the X-ray detection element in the X-ray incident direction to serve as a collimator plate is also available. Conceivable. However, in this method, there is a problem how to accurately position the partition plate 47. The detection element is formed on an X-ray detection element such as a photodiode 46 mounted on a printed circuit board. Therefore, the photodiodes 46 are arranged on the same plane in the array. Finally, by arranging the detection element array in a detector container in a polygonal shape, each channel is arranged substantially on an arc.
Since the arc is approximated by a polygon, strictly speaking, each element is located at an offset from the ideal position,
Actually, the positional deviation is slight, and no remarkable deviation occurs when reconstructing an image.

However, the partition plate 47 is connected to the detection element array 51.
When the collimator plate 49 is extended perpendicularly from the plane of (2) (50 is a substrate), the angle with respect to the incident X-ray is different between the central portion and the end portion of the detection element array 51 as shown in FIG. In addition, the size of the shadow of the incident X-ray generated by the partition plate 47 differs for each channel, and the output and characteristics of each photodiode 46 change, thereby deteriorating the measurement accuracy. In order to avoid this, it is necessary to arrange the collimator plates 49 to be inserted into each channel radially so as to be directed to the focal position of the X-ray tube after the completion of assembly. As described above, it is possible to radially attach the partition plate 47 to be inserted into the detection element array with high accuracy by providing a guide member or using a jig, but it is not easy to secure the accuracy. Also, the number of steps for assembly increases.

An object of the present invention is to provide an X-ray detector capable of reducing the number of assembling steps, eliminating the displacement between the detection element array and the collimator array, and improving the detection characteristics. It is another object of the present invention to provide an X-ray CT apparatus using an X-ray detector which has improved detection characteristics by eliminating a displacement between a detection element array and a collimator array.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a scintillator material for irradiating an X-ray transmitted through a subject, and a device for generating visible light generated by the X-ray irradiating the scintillator material. A predetermined number of X-ray detection elements for electrical conversion,
And a collimator plate that separates the X-ray detection elements from each other to form a channel and removes scattered X-rays incident from a direction other than the focal direction of the X-ray generation source according to the total number of channels of the X-ray detection element. A detection element array having each of collimator arrays provided on the X-ray incident side of the X-ray detection element, and an X-ray detector including a holding plate for holding the detection element array from both side surfaces; A groove for channel separation is provided, one end of the collimator plate is inserted into the groove, a vertical groove corresponding to a channel interval is provided on at least a part of a side surface of the holding plate, and a side portion of the collimator plate is provided in the vertical groove. The X-ray detector is inserted.

According to this structure, when the collimator array is assembled to the detection element array, the tip and side portions are positioned by the scintillator material and the holding plate, so that there is no positional displacement between the detection element array and the collimator array. Is inserted into the channel separation gab of the detection element, so that the collimator plate and the channel boundary of the detection element can be automatically aligned,
An X-ray detector having excellent X-ray detection characteristics can be obtained.
In addition, since the collimator array can be set wider in the channel direction than the element array, the work of radially arranging the collimator plates can be performed collectively, and the method of arranging the partition plates radially for each detection element array can be performed. In comparison, man-hours required for alignment of components and setup for assembly can be reduced.

The above-mentioned object is to provide an X-ray that has passed through a subject.
Measuring the X-ray attenuation of the subject using an X-ray detector that converts the X-rays into visible light with a scintillator material and converts the X-rays into light-electricity using a detection element array having a predetermined number of X-ray detection elements. In the X-ray CT apparatus for obtaining a CT image by X-ray detection, the X-ray detector separates the X-ray detection elements from each other to form a channel, and detects scattered X-rays incident from directions other than the focal direction of the X-ray source. A collimator plate to be removed is provided, and one end of the collimator plate is inserted into a groove provided for channel separation in the scintillator material, and is provided on at least a part of a side surface of a holding plate that holds the detection element array from both side surfaces. This is achieved by an X-ray CT apparatus having a configuration in which a side portion of the collimator plate is inserted into a vertical groove corresponding to the channel spacing.

According to this configuration, when assembling the collimator array to the detection element array, the front end and the side are positioned by the scintillator material and the holding plate, and the displacement between the detection element array and the collimator array is eliminated, An X-ray CT apparatus equipped with an X-ray detector having excellent detection characteristics can be obtained. Therefore, the deterioration of the CT image due to the displacement between the detection element array and the collimator array is reduced, and the measurement accuracy can be improved.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a detection module of an X-ray detector for a CT apparatus according to an embodiment of the present invention. The detection element array 1 includes module members 2a and 2b
The collimator array 3 is disposed between the module members 2a and 2b. The collimator array 3 and the holding plates 6a and 6b are screws 4
Are attached to the module members 2a and 2b. The collimator array 3 includes a collimator plate 5 disposed above the detection unit and holding plates 6a for holding the collimator plate 5 from both sides.
6b. An X-ray detection element 7 in which a scintillator and a photoelectric conversion element (both not shown) are combined is provided on the substrate of the detection element array 1, and the respective outputs are provided via a connector 8 provided at the other end. It can be connected to an external circuit (not shown). Module member 2
A screw hole 9 for attaching the detection element array 1 to a detector container (not shown) is provided on the side surface of “a”.

FIG. 2 shows a right side view of the detection module of FIG. X arranged on the substrate of the detection element array 1
A part of the collimator plate 5 is fitted in a gap (groove) between the channels of the line detecting element 7. Detection element array 1
Are attached to the polygon surfaces of the module members 2a and 2b by screws 10.

FIG. 3 shows a section in the circumferential direction of the collimator plate 5 of the detection module 1 of FIG. Holding plate 6
The detection element array 1 is mounted in a polygonal shape such that each of the collimator plates 5 radially mounted by a and 6b is combined with the gap between the channels. At this time, the collimator plate 5 is arranged at the boundary between the adjacent detection element arrays 1 so that

FIG. 4 shows the details of the collimator array 3. The collimator plate 5 is disposed on the holding plates 6a and 6b at a predetermined angle and pitch. As a method of arranging the collimator plate 5 at a predetermined angle and pitch, the holding plate 6
A groove (not shown) is provided on the side surface of each of the holding plates 6a and 6b, and the collimator plate 5 is inserted therein and fixed with an adhesive, or the positioning of the collimator plate 5 is performed using a jig.
There is a method of applying an adhesive to the side surface of 6b and fixing it while pressing. A plurality of screw holes 11 are provided on side surfaces of the holding plates 6a and 6b, and the module members 2a and 2b can be attached.

FIG. 5 shows a detailed configuration of the detection element array 1. The detection element array 1 includes a long plate-shaped substrate 12, an X-ray detection element 7 mounted on an upper surface thereof, and a connector 8 disposed at an end. The width of the substrate 12 is
The width is set to be the same as the width of the installed X-ray detection element 7. Also,
The mounting holes 13 are provided on both sides of the X-ray detecting element 7 on the substrate 12.
Is provided.

FIG. 6 shows a process of manufacturing the detection element array 1 of FIG. (A) shows a state where the photodiode array 14 is mounted on the surface of the substrate 12, and (b) shows a state where the scintillator material 15 is adhered to the light receiving surface of the photodiode array 14 with a transparent adhesive. On the scintillator material 15, light emitted from the scintillator 15 due to incident X-rays is efficiently emitted from the photodiode 14.
The reflection layer 16 is provided to guide the light to the light receiving surface. The reflective layer 16 can be formed by vapor deposition of aluminum or the like having high light reflectance, or by applying a white paint to the surface. The width of the scintillator material 15 attached to the photodiode 14 is slightly larger than that of the photodiode 14. Next, a groove 15a reaching the photodiode 14 is formed in the scintillator material 15 as shown in FIG. By performing groove processing also on both ends, the scintillator 15 has a finish that matches the width of the photodiode 14. The width of the groove 15a is larger than the thickness of the collimator plate 5.

FIG. 7 is a front view showing a state where the collimator 3 and the detection element array 1 are assembled. Holding plate 6 not shown
The module members 2a, 2b are attached by screws 4 outside the a, 6b. The module members 2a, 2
On the polygon surface b, three detection element arrays 1-1 and l
−2 and 1-3 are attached by screws 10.
In FIG. 7, the two leftmost detection element arrays 1-1, l
Reference numeral -2 indicates a state where the attachment with the screw 10 is completed. Also, the third detection element array 1-3 from the left shows a state in the middle of mounting.

FIG. 8 shows a cross-sectional view of the unit of FIG. Referring to FIG. 8, the collimator plate 5 and the X-ray detection element 7
Can understand each other's positional relationship. The radially arranged collimator plates 5 are positioned so as to fit into the grooves provided in the scintillator 15 on the detection element array 1, and then attached to the polygon surface. Collimator plate 5
On the other hand, the detection element array 1 is arranged in a polygon shape.
For this reason, the channel near the center of the detection element array 1 is parallel to the groove and the collimator plate 5, but at the end of the channel, the collimator plate 5 is inserted into the groove 15a slightly obliquely. However, if the width of the detection element array 1 is about 30 mm, the thickness of the scintillator 15 into which the collimator plate 5 is inserted is about 1 mm, and the radius of the polygon surface on which the detection element array 1 is arranged is about 1000 mm, the detection element The inclination of the collimator plate 5 at the end channel of the array 1 is 1
If the width of the groove 15a is set to be about 20 mm to 30 mm wider than the thickness of the collimator plate 5, a sufficient clearance for assembly can be obtained.

The collimator plate 5 inserted into the groove 15a of the scintillator 15 functions as a partition plate for preventing light emitted from the inside of the scintillator due to incident X-rays from leaking to an adjacent channel, and is also provided outside the side surface of the scintillator 15. It serves as a reflector that reflects the emitted light and returns it to the light receiving surface of the photodiode 14. For this reason, if the reflective layer 16 is provided on at least the surface of the collimator plate 5 at the portion inserted into the groove 15a of the scintillator 15, the detection power can be increased. Then, the module members 2a, 2b
When a predetermined number of the detection element arrays 1 are arranged in a polygon on the above, the detection element module is completed.

Next, another method of assembling the detection element module will be described with reference to FIGS.

In the above method, the collimator array 3 is assembled in advance and incorporated in the detection element module. On the other hand, in the method described below, the detection element array 1 is fixed in a polygonal shape, and then the collimator plate 5 is attached. Insert and assemble. First, as shown in FIG. 9, the holding plates 6a and 6b are attached to the inside of the module members 2a and 2b with the screws 4. Radial grooves for attaching the collimator plate 5 are formed in the holding plates 6a and 6b in advance.
The detection element array 1 is attached to the polygon surfaces of the module members 2a and 2b with screws 10.

FIG. 10 shows a holding plate 6a having a polygonal surface.
6b shows a state in which the detection element array 1 is attached. As shown in FIG. 11, the side portion of the collimator plate 5 is inserted along the groove 60 provided on the side wall of the holding plates 6a and 6b, and the tip end of the collimator plate 5 is inserted into the channel separation groove 15a of the detection element array 1. Inserted. The collimator plate 5 blocks the incident scattered X-rays, and the tip of the collimator plate 5 not only separates the channel to prevent crosstalk but also prevents the scintillator 1 from scattering.
5 functions as a reflector for efficiently guiding the light emission to the light receiving surface of the photodiode. If a reflective layer having high light reflectance is provided on the surface of the portion in contact with the side surface of the scintillator 15, the output of the X-ray detecting element 7 can be increased.

Therefore, as shown in FIG. 12B, a light reflecting layer 23 is provided on the surface of the collimator plate 5. Alternatively, as shown in FIGS. 13A and 13B, even when the light reflecting layer 23 is provided only in a portion inserted into the scintillator 15, the light emitted from the scintillator 15 can be used efficiently. The detection power can be increased. After the collimator plate 5 provided with the light reflection layer 23 is inserted into the holding plates 6a and 6b and the groove 15a of the detection element array 1 in this order, and the collimator plate 5 is fixed with an adhesive, the detection element module can be assembled. Complete.

FIG. 14 shows the positional relationship between the holding plate 6 and the detection element array 1. As shown in FIGS. 15A and 15B, when the width of the groove 60 formed in the holding plate 6 (6a, 6b) is constant, the alignment between the detection element array 1 and the holding plate 6 becomes considerably large. If it is not performed accurately, the operation of inserting the collimator plate 5 becomes difficult. On the other hand, as shown in FIG. 16, the width of the groove 60 provided in the support plate 6 (6a, 6b) is different in the radial direction, and the outer width is increased (the inner width w2 is smaller than the outer width w2). In the case where the width is larger than the width w1, the alignment between the detection element array 1 and the holding plate 6 does not cause any problem even if it is slightly rough. In this case, the position of the collimator plate 5 is determined by the groove 60 of the detection element array 1 and the groove 60 on the narrow w1 side.

FIG. 17 shows a groove 6 for fixing the collimator plate 5.
Reference numeral 0 denotes a holding plate 6 (6a, 6b) having a configuration provided only on a part of the X-ray incidence side. As shown in FIG. 17B, the formation portion of the groove 60 protrudes downward, and the holding plate 6 has an L-shaped cross-sectional shape. In this configuration, even when the alignment between the holding plate 6 and the detection element array 1 is slightly rough, the collimator plate 5 can be inserted in accordance with the channel separation groove position of the detection element array 1.

FIG. 18 shows a state in which the collimator plate 5 is held by the holding plate 6 having the structure shown in FIG. 17 ((a) is a front sectional view, and (b) is a side sectional view). The side surface of one end of the collimator plate 5 is fitted into the groove 60 of the holding plate 6, and the collimator plate 5
Is positioned by fitting into the groove 15a of the detection element array 1.

FIG. 19 shows a state in which the detecting element module 1 is disposed inside the detector container. The completed modules 17 are arranged on a predetermined arc inside the container. The modules 17 are fixed to the side wall 18 of the detector container such that the distance between the modules becomes a predetermined value.

FIG. 20 shows a state where the module 17 is housed in the detector container. The collimator plate 5 and the holding plates 6a and 6b are screwed to the polygon surface of the module member 2 while being sandwiched by the module members 2a and 2b.
Fixed by 0. The detection element array 1 and the collimator array 5 in this state are housed so as to be located at the center of the space surrounded by the container side wall 18, the bottom plate 19 of the detector container, and the front cover 21, and the outer surface of the module member 2a. Is in contact with the container side wall 18.

Next, a second embodiment will be described with reference to FIGS. FIG. 21 shows a detection module in which the detection element array 1 and the collimator array 5 are combined. A polygon surface is formed on the holding plates 6a and 6b, and the detection element array 1 is attached to the inner surface. The holding plates 6a and 6b are provided with two screw holes 9 for attachment to the detector container on the side surface. An X-ray detection element 7 in which a scintillator and a photoelectric conversion element (photodiode) are combined is arranged on the substrate of the detection element array 1, and each output of the X-ray detection element 7 is connected to a connector 8 provided at the other end. Can be sent to an external circuit. The second embodiment is different from the holding plate 6 of the first embodiment.
Only the part where the (6a, 6b) and the module member 2 (2a, 2b) are integrated is different, and there is no change in the overall configuration.

FIG. 22 shows a detailed structure of the support plate 6 (only the holding plate 6a is shown). In the figure, (a) is a front view, (b) is a sectional view, and (c) is a bottom view. Holding plate 6
The fan-shaped outer diameter portion is a polygon surface, and a screw hole 22 for attaching the detection element array 1 is provided at the center of each surface (six in FIG. 22) corresponding to each of the polygon detection element arrays 1. Is provided. Also in this embodiment, the method of assembling by inserting a part of the collimator plate 5 into the channel separation groove portion of the detection element array 1 is the first method.
This is the same as the embodiment. After the assembled detection module is placed in the detector container, it is fixed and completed.

[0042]

As described above, according to the present invention, the relative positioning between the detection element array and the collimator array can be automatically performed at the time of assembling. X with good detection characteristics
A line detector and an X-ray CT apparatus using the same can be obtained. In addition, since the collimator array can be set wider in the channel direction than the element array, the work of radially arranging the collimator plates can be performed collectively.
Compared with the method of arranging the partition plates radially for each detection element array, the number of steps required for alignment of components and preparation for assembly can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a detection module of an X-ray detector for a CT device according to an embodiment of the present invention.

FIG. 2 is a right side view of the detection module of FIG.

FIG. 3 is a circumferential sectional view of a collimator plate portion of the detection module of FIG. 1;

FIG. 4 is a perspective view showing details of a collimator array.

FIG. 5 is a diagram showing an appearance of a detection element array.

6 shows a process of manufacturing the detection element array of FIG. 5,
(A) shows the state of only the substrate and the photodiode array, (b) shows the state where a scintillator material provided with a reflective layer on the substrate and the photodiode is bonded, and (c) shows the groove processing of the scintillator material in each channel. Indicates a separated state.

FIG. 7 is a front view showing a state where the collimator and the detection element array are assembled.

FIG. 8 shows a cross section of FIG.

FIG. 9 is a front view showing another configuration of the detection module according to the first embodiment.

FIG. 10 is a view showing a cross section of the detection module of FIG. 9;

FIG. 11 is a view showing a longitudinal section of FIG. 9;

FIG. 12 shows a first embodiment of a collimator plate,
(A) is a front view, (b) is a side sectional view.

FIG. 13 shows a second embodiment of the collimator plate,
(A) is a front view, (b) is a side sectional view.

FIG. 14 is a cross-sectional view illustrating a mutual positional relationship between a collimator plate, a holding plate, and a detection element.

FIG. 15 shows a configuration of a holding plate having a uniform groove width in each part,
(A) is a front view, (b) is a sectional view.

FIG. 16 is a front view showing a configuration of a holding plate having different groove widths in a radial direction.

17A and 17B show a holding plate having a configuration in which the collimator plate holding portion is limited to a part on the side of the X-ray incidence portion, where FIG.
Is a sectional view.

18A and 18B show a state where the collimator plate is held by the holding plate having the configuration shown in FIG. 17, wherein FIG. 18A is a front sectional view, and FIG.

FIG. 19 is a diagram showing an arrangement of modules on a detector.

FIG. 20 is a diagram illustrating a cross-sectional view of the detector according to the embodiment.

FIG. 21 is a diagram illustrating an appearance of a module according to a second embodiment.

FIG. 22 is a diagram illustrating a holding plate of the collimator,
(A) is a front view, (b) is a cross-sectional view, and (c) is a bottom view.

FIG. 23 is a schematic diagram illustrating the effect of scattered X-rays obliquely entering an ionization chamber detector, which is a type of X-ray detector.

FIG. 24 is a schematic diagram illustrating the effect of scattered X-rays obliquely entering a solid-state detector that is a type of X-ray detector.

FIG. 25 is an explanatory diagram showing that when a partition plate of a detection element array of a solid state detector is extended to be a collimator plate, a shadow portion of incident X-rays is generated in an end channel by the partition plate.

[Explanation of symbols]

 Reference Signs List 1 detection element array 2a, 2b module member 3 collimator array 5 collimator plate 6, 6a, 6b holding plate 7 X-ray detection element 9, 11 screw hole 12 substrate 15 scintillator material 15a, 60 groove 16 reflection layer 18 container side wall 19 bottom plate 21 Front cover 23 Light reflection layer

Claims (2)

[Claims] 1. A scintillator material to be irradiated with X-rays transmitted through a subject, a predetermined number of X-ray detection elements for photoelectrically converting visible light generated by the X-rays irradiated to the scintillator material,
And a collimator plate which separates the X-ray detection elements from each other to form a channel and removes scattered X-rays incident from a direction other than the focal direction of the X-ray source. In the X-ray detector including a detection element array having each of collimator arrays provided on the X-ray incidence side of the X-ray detection element, and a holding plate for holding the detection element array from both sides, a channel separation is performed on the scintillator material. A groove for inserting the one end of the collimator plate into the groove, a vertical groove corresponding to a channel interval is provided on at least a part of a side surface of the holding plate, and a side portion of the collimator plate is inserted into the vertical groove. An X-ray detector characterized in that: 2. The method according to claim 1, wherein the X-rays transmitted through the subject are visualized by a scintillator material, and the X-rays are subjected to photoelectric conversion by a detection element array having a predetermined number of X-ray detection elements. In an X-ray CT apparatus for obtaining a CT image by measuring attenuation of X-rays in a sample portion, the X-ray detector separates X-ray detection elements from each other to form a channel, and an X-ray source A collimator plate for removing scattered X-rays incident from a direction other than the focal direction of the light emitting device. One end of the collimator plate is inserted into a groove provided for channel separation in the scintillator material, and holds the detection element array from both side surfaces. An X-ray CT apparatus, wherein a side portion of the collimator plate is inserted into a vertical groove corresponding to a channel interval provided on at least a part of a side surface of the holding plate. [0001]