JPH0525383U - X-ray detector for X-ray CT device - Google Patents

Abstract

(57) [Abstract] [Purpose] The relative positional relationship between the scintillator surface and the light-reflecting film of each X-ray detection element array is maintained in a constant state without variations, and variations in sensitivity characteristics are reduced to achieve high measurement. Provided is an X-ray detector for an X-ray CT apparatus, which can obtain accuracy. [Structure] The entire surface of each X-ray detection element array on the X-ray incident side has a property of high and uniform surface light reflectance and high X-ray transmittance, and can maintain a constant distance from the surface of the scintillator. A light reflection plate made of a thin metal plate is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an X-ray detector for an X-ray CT apparatus, and in particular, it reduces variations in sensitivity characteristics among a large number of X-ray detection element arrays that are arranged adjacent to each other in a detector case to achieve high measurement. It relates to an X-ray detector suitable for obtaining accuracy.

[0002]

[Prior Art]

 An X-ray detector for a conventional X-ray CT apparatus will be described with reference to FIGS. 5 is an overall perspective view showing the appearance of the X-ray detector, FIG. 6 is a sectional view taken along line VI-VI of FIG. 6 showing a polygonal arrangement of the X-ray detection element array, and FIG. 7 is an explanatory view of the configuration of the X-ray detection element array. 7A is a perspective view showing the appearance, FIG. 8B is a detailed sectional view taken along the line VIIb-VIIb of FIG. 7A, and FIG. 8 is an explanatory view of the manufacturing process of the X-ray detection element array.

As shown in FIGS. 5 and 6, the X-ray detector includes a detector case 2 formed in an arc shape around the focal point of the X-ray tube 1, and an X-ray entrance for removing scattered rays. A collimator 3 provided, a plurality of X-ray detection element arrays 4 arranged in a polygonal shape with respect to the focal point of the X-ray tube 1 in the detector case 2, and incident light converted by each X-ray detection element array 4. It is composed of a connector 5 and the like for transmitting X-ray signals to an external amplifier. 6 is a subject. In addition, as shown in FIGS. 7A and 7B, the X-ray detection element array 4 is a multi-channel array in which a plurality of light receiving elements are arranged in parallel on the substrate 7 with an adhesive 10 at a predetermined pitch. Of the photoelectric conversion element 8, the photoelectric conversion element 8 and the scintillator 9 which are fixedly adhered to each other through the transparent adhesive 11 and emit light according to the intensity of the incident X-ray, and the light receiving elements of the photoelectric conversion element 8 are separated from each other. It is composed of a partition plate 13 and the like inserted in the groove 12 thus formed. For the photoelectric conversion element 8, for example, a silicon photodiode having a PIN type structure is used, and the partition plate 13 has both longitudinal ends thereof fixed to the photoelectric conversion element 8 or the substrate 7 with an adhesive 14.

Next, a manufacturing process of the detection element portion of the X-ray detection element array 4 will be described with reference to FIG. First, as shown in FIG. 8 (a), a silicon photodiode 8 constituting a light receiving element for several channels is adhered onto a substrate 7 with an adhesive 10 shown in FIG. 7 (b), and the adhered silicon photodiode 8 is adhered onto the adhered silicon photodiode 8. The plate-shaped scintillator 9 processed to have a predetermined thickness is arranged so that the light emitting surface of the scintillator 9 exactly corresponds to the sensitive portions of the light receiving elements of the silicon photodiode 8 in FIG. The transparent adhesive 11 having a high light transmittance shown in b) is used to bond in the state shown in FIG. 8B. In this case, the area of the silicon photodiode 8 is slightly larger than the area of the scintillator 9 as shown in FIG. 8 (b). Then, as shown in FIG. 8C, a plurality of grooves 12 are formed in parallel with the scintillator 9 to separate the respective channels of the silicon photodiode 8. The groove 12 is processed until the bottom of the groove 12 reaches a depth reaching the silicon photodiode 8 as shown in FIG. 7B. Then, as shown in FIG. 8D, the partition plate 13 is inserted into the processed groove 12, and both ends of the inserted partition plate 13 are bonded and fixed with an adhesive (14 shown in FIG. 7A). Complete.

The X-ray detection element array 4 completed by the above process is arranged in a polygon shape in the detector case 2 adjacent to the focal point of the X-ray tube 1 in a polygonal shape. Make up. In this case, on the surface of the X-ray detection element array 4 on the X-ray incident side, as shown in FIG. 4, the light emitted from the scintillator 9 is efficiently incident on the silicon photodiode 8 to reduce the output of the X-ray detector. In order to prevent this, a light reflecting film 15 made of a material having a high light reflectance, such as a polyester film having aluminum vapor-deposited thereon, is provided.

[0006]

[Problems to be solved by the device]

 In the above-mentioned conventional X-ray detector, when a plurality of X-ray detecting element arrays 4 are arranged in the detector case 2, the surface 9a on the X-ray incidence side of each scintillator 9 and the surface 9a are installed. The relative positional relationship with the light-reflecting film 15, that is, the contact state between them and the gap between them was different both within the X-ray detection element array 4 and between adjacent X-ray detection element arrays 4. The reason for this difference is that the thickness dimensions of the silicon photodiode 8 and the scintillator 9 are almost constant, so that the layer thickness of the adhesive 10, 11 is uniform, but mainly As shown in FIG. 4, the difference was in the amount of protrusion of the upper end of the partition plate 13 protruding from the surface 9a. This variation in the relative positional relationship between the surface 9a and the light reflecting film 15 causes a problem that the sensitivity characteristics of the detected X-rays vary and a high-quality image cannot be obtained. Therefore, each scintillator has a problem. It has been required to keep the relative positional relationship between the surface 9a of 9 and the light reflecting film 15 constant.

In view of the above-mentioned problems of the prior art, the present invention varies the relative positional relationship between the scintillator surface and the light reflecting film of each X-ray detection element array, which are arranged adjacent to each other in the detector case. It is an object of the present invention to provide an X-ray detector for an X-ray CT apparatus, which can maintain high stability in a constant state, reduce variations in sensitivity characteristics, and obtain high measurement accuracy.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a scintillator that emits light according to the intensity of incident X-rays, and a multi-channel photoelectric conversion element having a light-receiving surface bonded to the scintillator and the other surface disposed on a substrate. , An X-ray detection device array in which a plurality of X-ray detection device arrays each including a partition plate inserted into a groove for separating each channel of the photoelectric conversion device are arranged adjacent to each other in a detector case. In the line detector, the entire surface of the X-ray incidence side of each of the X-ray detection element arrays arranged adjacent to each other has a high surface light reflectance and a uniform surface reflectance, and a high X-ray transmittance. A light reflection plate made of a thin metal plate that can maintain a certain distance from the surface of the above is arranged.

[0009]

[Action]

 With the above configuration, the relative positional relationship between the surface of each scintillator and the light reflection plate is not affected by the individual protrusion amount of the partition plate upper end protruding from the surface, and the relative positional relationship is detected by each X-ray detection. It is possible to maintain a constant state without variation over the entire X-ray incidence side of the element array. Therefore, it is possible to reduce variations in sensitivity characteristics between the X-ray detection element arrays and obtain high measurement accuracy.

[0010]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. In the figure, the same symbols as those in FIGS. 4 to 8 indicate the same components. 1 is a side sectional view of the X-ray detector in the channel separation direction, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is an enlarged view of a main part of FIG.

In the figure, reference numeral 16 denotes a thin metal light reflection plate disposed on the entire surface of the scintillator surface 9a of each X-ray detection element array 4, and replaces the conventional light reflection film. The light reflection plate 16 is made of a material such as aluminum or stainless steel that has a high surface light reflectance and is uniform and has a high X-ray transmittance. Then, as shown in FIG. 3, in order to maintain a certain distance from the scintillator surface 9a, for example, the thickness is set to 0.3 mm so as to have a predetermined rigidity, and the surface of the metal is mirror-finished. The partition plate 13 is formed of a thin plate and is pressed against the upper end of the partition plate 13 protruding from the surface 9a through the packing material 17 and the light shielding plate 18, and arranged in a polygonal shape corresponding to the arrangement of the X-ray detection element array 4.

With the above configuration, the relative positional relationship between each scintillator surface 9a and the light reflection plate 16 is not affected by the individual projection amount of the upper end of the partition plate 13 projecting from the surface 9a, and The positional relationship can be maintained in a constant state without variation over the entire X-ray incident side of each X-ray detection element array 4. Therefore, it is possible to reduce variations in sensitivity characteristics among the X-ray detection element arrays 4, and it is possible to obtain a high-quality image and high measurement accuracy.

[0013]

[Effect of the device]

 As described above, the X-ray detector for the X-ray CT apparatus of the present invention has a high surface light reflectance and a uniform surface light reflectance on the entire X-ray incidence side of each X-ray detection element array arranged adjacent to each other. Moreover, since the light reflection plate made of a thin metal plate having a property of high X-ray transmittance and capable of maintaining a constant distance from the surface of the scintillator is arranged, the relative position between the scintillator surface and the light reflection plate is set. The relationship can be made uniform, and the sensitivity characteristic of each X-ray detection element array can be made uniform without fluctuation, and an X-ray detector with high measurement accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view of an X-ray detector according to an embodiment of the present invention in a channel separation direction.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a side sectional view showing a light reflecting film in a conventional X-ray detecting element array.

FIG. 5 is an overall perspective view showing the appearance of a conventional X-ray detector.

6 is a VI-VI sectional view of FIG. 6 showing a polygonal arrangement of an X-ray detection element array.

7A and 7B are explanatory views of the configuration of an X-ray detection element array, in which FIG. 7A is a perspective view showing the external appearance, and FIG.
IIb is a detailed view of a cross section.

FIG. 8 is an explanatory diagram of the manufacturing process of the X-ray detection element array.

[Explanation of symbols]

 2 Detector Case 4 X-ray Detecting Element Array 7 Substrate 8 Photoelectric Conversion Element (Silicon Photodiode) 9 Scintillator 9a Surface 13 Partition Plate 15 Light Reflecting Film 16 Light Reflecting Plate

Claims (1)

[Scope of utility model registration request] 1. A scintillator that emits light according to the intensity of incident X-rays, a multi-channel photoelectric conversion element having a light-receiving surface bonded to the scintillator and the other surface disposed on a substrate, and each of the photoelectric conversion elements. In an X-ray detector for an X-ray CT apparatus, a plurality of X-ray detection element arrays each including a partition plate inserted in a groove for separating channels are arranged adjacent to each other in a detector case. The entire surface of each of the arrayed X-ray detection element arrays on the X-ray incidence side has a property of high surface light reflectance and uniformity and high X-ray transmittance, and can maintain a constant distance from the surface of the scintillator. An X-ray detector for an X-ray CT apparatus, which is provided with a light reflecting plate made of a thin metal plate.