JPH0619461B2 - X-ray CT detector - Google Patents
X-ray CT detectorInfo
- Publication number
- JPH0619461B2 JPH0619461B2 JP30183989A JP30183989A JPH0619461B2 JP H0619461 B2 JPH0619461 B2 JP H0619461B2 JP 30183989 A JP30183989 A JP 30183989A JP 30183989 A JP30183989 A JP 30183989A JP H0619461 B2 JPH0619461 B2 JP H0619461B2
- Authority
- JP
- Japan
- Prior art keywords
- scintillator
- detector
- ray
- light
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000005562 fading Methods 0.000 claims description 23
- 230000006866 deterioration Effects 0.000 claims description 11
- 230000005855 radiation Effects 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000004061 bleaching Methods 0.000 claims description 5
- 239000007844 bleaching agent Substances 0.000 claims description 2
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 239000010408 film Substances 0.000 description 39
- 230000035945 sensitivity Effects 0.000 description 22
- 238000000295 emission spectrum Methods 0.000 description 6
- 239000003973 paint Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 238000002834 transmittance Methods 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Apparatus For Radiation Diagnosis (AREA)
- Nuclear Medicine (AREA)
- Measurement Of Radiation (AREA)
Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、Ｘ線ＣＴ装置に用いられ被写体を透過したＸ
線を検出して被写体の断層像を得るためのＸ線ＣＴ用検
出器に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an X-ray that is used in an X-ray CT apparatus and transmits an object.
The present invention relates to an X-ray CT detector for detecting a line and obtaining a tomographic image of a subject.
（従来の技術） 従来、この種のＸ線ＣＴ用検出器として、例えば第６図
に示すようなものがある。図においてこの検出器１００
は、複数のシンチレータ素子１０１ａが接着されて成る
シンチレータ１０１と光電変換手段としてのフォトダイ
オード１０２とが接着剤１０３により接着されて組み合
され、フォトダイオード１０２は基板１０４に組み立て
られている。シンチレータ１０１のＸ線入射面及び側面
には、光反射率を有する反射剤としての白色ペイントが
塗布されて光反射層１０５が形成されており、各シンチ
レータ素子１０１ａから発する光が光反射層１０５で反
射して効率良くフォトダイオード１０２に入射するよう
にされている。(Prior Art) Conventionally, as an X-ray CT detector of this type, there is one shown in FIG. 6, for example. In the figure, this detector 100
The scintillator 101 formed by adhering a plurality of scintillator elements 101a and the photodiode 102 as the photoelectric conversion means are adhered and combined by the adhesive 103, and the photodiode 102 is assembled on the substrate 104. The X-ray incidence surface and the side surface of the scintillator 101 are coated with white paint as a reflecting agent having a light reflectance to form a light reflection layer 105, and the light emitted from each scintillator element 101a is reflected by the light reflection layer 105. The light is reflected and efficiently incident on the photodiode 102.
上記検出器１００が設けられたＸ線ＣＴ装置により被写
体の撮影を行う際には、被写体にＸ線が照射され、被写
体を通過したＸ線が第６図中矢印方向にシンチレータ１
０１に入射し、それによりシンチレータ１０１で発生し
た光がフォトダイオード１０２に入射し、フォトダイオ
ード１０２は映像信号としての電気信号を次の信号処理
系に送る。そして、Ｘ線ＣＴ装置はこの映像信号に基い
て被写体の断層像（ＣＴ像）を構成し表示する。When a subject is photographed by the X-ray CT apparatus provided with the detector 100, the subject is irradiated with X-rays, and the X-rays that have passed through the subject scintillator 1 in the direction of the arrow in FIG.
The light generated by the scintillator 101 is incident on the photodiode 102, and the photodiode 102 sends an electric signal as a video signal to the next signal processing system. Then, the X-ray CT apparatus constructs and displays a tomographic image (CT image) of the subject based on this video signal.
（発明が解決しようとする課題） しかしながら上記した従来技術の場合には、次に説明す
るような課題があった。(Problems to be Solved by the Invention) However, in the case of the above-described conventional technique, there are the following problems.
シンチレータ材料にはＸ線照射により着色部分（ｃｏｌ
ｏｕｒ ｃｅｎｔｅｒ）を生じる性質があり、上記シン
チレータ１０１にこのような着色部分が生じると、シン
チレータ１０１で発生した可視光は着色部分に吸収され
てシンチレータの光出力が低下し、検出器１００の感度
が低下する。第７図はＧｄ２Ｏ２Ｓ：Ｐｒセラミックか
ら成るシンチレータへのＸ線照射線量と検出器の感度と
の関係を示す図である。第７図に示すように、シンチレ
ータへのＸ線照射線量が多いほど検出器の感度が低下す
る。そして、このようなシンチレータの放射線劣化によ
る検出器の感度低下により、Ｘ線ＣＴ装置におけるＣＴ
値の変動やアーチファクトが生じるという問題があっ
た。The scintillator material is colored by X-ray irradiation (col
If there is such a colored portion in the scintillator 101, visible light generated in the scintillator 101 is absorbed in the colored portion, the light output of the scintillator is lowered, and the sensitivity of the detector 100 is reduced. descend. FIG. 7 is a diagram showing the relationship between the X-ray irradiation dose to the scintillator made of Gd 2 O 2 S: Pr ceramic and the sensitivity of the detector. As shown in FIG. 7, the higher the X-ray irradiation dose to the scintillator, the lower the sensitivity of the detector. Then, due to the decrease in the sensitivity of the detector due to the radiation deterioration of the scintillator, CT in the X-ray CT apparatus is
There was a problem that fluctuations in values and artifacts occurred.
例えば第８図に示すように、小さな被写体１１１を何回
か撮影した後に大きな被写体１１２を撮影する場合に
は、まず小さな被写体１１１撮影時には、Ｘ線管球１１
３から発生したＸ線は被写体１１１を透過して検出器１
００を照射するが、このとき検出器１００において、被
写体１１１を透過したＸ線が照射する小部分１００ａの
Ｘ線照射線量はＸ線管球１１３からのＸ線が被写体１１
１を透過せずに直接照射する部分１００ｂのＸ線照射量
より少なくなり、検出器１００の感度分布はチャンネル
間で段差を生じるようになる。この後大きな被写体１１
２を撮影すると、検出器１００の感度分布に段差がある
ために表示画像にアーチファクトが現れる。For example, as shown in FIG. 8, when the large subject 112 is photographed after the small subject 111 is photographed several times, first, when the small subject 111 is photographed, the X-ray tube 11 is used.
X-rays generated from the detector 3 pass through the subject 111 and the detector 1
00, but at this time, in the detector 100, the X-ray irradiation dose of the small portion 100a irradiated by the X-rays transmitted through the subject 111 is the X-ray from the X-ray tube 113.
The amount of X-ray irradiation becomes smaller than that of the portion 100b that directly irradiates 1 without passing through 1, and the sensitivity distribution of the detector 100 has a step difference between channels. After this, a large subject 11
When 2 is photographed, an artifact appears in the display image because the sensitivity distribution of the detector 100 has a step.
また、小さな被写体１１１を撮影せずに大きな被写体１
１２のみを撮影する場合には、このような感度段差は生
じないが、検出器１００はシンチレータの放射線劣化に
よりほぼ全チャンネルにわたって均一に感度が低下する
ので、ＣＴ値の変動が生じる。In addition, the large subject 1 without photographing the small subject 111
When only 12 is imaged, such a sensitivity step does not occur, but since the sensitivity of the detector 100 deteriorates uniformly over almost all channels due to radiation deterioration of the scintillator, CT value fluctuations occur.
本発明は上記した従来技術の課題を解決するためになさ
れたもので、その目的とするところは、シンチレータの
放射線劣化による検出精度の低下を防止し、ＣＴ像を表
示ずる際には表示画像の画質低下を防止することができ
るＸ線ＣＴ用検出器を提供することにある。The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object thereof is to prevent a decrease in detection accuracy due to radiation deterioration of a scintillator and to display a display image when a CT image is displayed. An object of the present invention is to provide a detector for X-ray CT capable of preventing deterioration of image quality.
［発明の構成］ （課題を解決するための手段） 上記目的を達成するために、本発明にあっては、シンチ
レータと光電変換手段とが組み合されて成るＸ線ＣＴ用
検出器において、前記シンチレータの放射線劣化による
着色部分を退色させるために該シンチレータに光を照射
する退色用光源を備え、該退色用光源が発する光の波長
を前記シンチレータ素子が発する光の波長とは異なら
せ、前記シンチレータ素子のＸ線入射面に、前記退色用
光源が発する光を透過させ、かつ前記シンチレータが発
する光を反射する反射膜を形成して成ることを特徴とす
る。[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the present invention, an X-ray CT detector comprising a combination of a scintillator and photoelectric conversion means, The scintillator is provided with a bleaching light source for irradiating the scintillator with light in order to bleach a colored portion due to radiation deterioration, and the wavelength of the light emitted by the bleaching light source is different from the wavelength of the light emitted by the scintillator element. The X-ray incidence surface of the device is characterized in that a reflection film that transmits the light emitted from the light source for fading and reflects the light emitted from the scintillator is formed.
上記反射膜としては、干渉膜、時に誘電体多層膜が好適
である。As the reflection film, an interference film, and sometimes a dielectric multilayer film is suitable.
（作用） 上記構成を有する本発明のＸ線ＣＴ用検出器において
は、シンチレータに形成された反射膜は退色用光源が発
する光を透過させるので、退色用光源から発生した光を
反射膜を透過させてシンチレータに入射させることがで
きる。そして、Ｘ線照射によりシンチレータに生じた着
色部はこの退色用光源からの光が照射されることにによ
り退色し、それにより感度が低下していた検出器の感度
を元の状態に戻すことができる。(Operation) In the X-ray CT detector of the present invention having the above-described configuration, the reflection film formed on the scintillator transmits the light emitted from the light source for fading, so that the light generated from the light source for fading is transmitted through the reflection film. And can be made incident on the scintillator. The colored portion produced on the scintillator by the X-ray irradiation is discolored by being irradiated with the light from the light source for fading, and the sensitivity of the detector whose sensitivity has been lowered can be returned to the original state. it can.
また、上記反射膜はシンチレータが発する光を反射する
ので、Ｘ線照射時にシンチレータで発生した光を反射膜
で反射させて、効率良く光電変換手段に入射させること
ができる。Further, since the reflective film reflects the light emitted by the scintillator, the light generated by the scintillator during X-ray irradiation can be reflected by the reflective film and efficiently enter the photoelectric conversion means.
さらに、上記反射膜として干渉膜、特に誘電体多層膜を
用いた場合には、シンチレータが発する光に対して高反
射率の反射膜とすることができるため、好感度の検出器
を得ることができる。Furthermore, when an interference film, particularly a dielectric multilayer film, is used as the reflection film, a reflection film having a high reflectance with respect to the light emitted by the scintillator can be obtained, so that a detector with favorable sensitivity can be obtained. it can.
（実施例） 以下に、本発明の実施例を図に基いて説明する。第１図
は本発明の一実施例のＸ線ＣＴ用検出器の一部の構成を
示す縦断面図，第２図は同実施例のＸ線ＣＴ用検出器の
全体の構成を示す縦断面図である。(Example) Below, the Example of this invention is described based on drawing. FIG. 1 is a vertical cross-sectional view showing a part of the structure of an X-ray CT detector according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing the whole structure of an X-ray CT detector of the same embodiment. It is a figure.
第２図において、１はＸ線ＣＴ用検出器を示しており、
概略シンチレータ２と光電変換手段としてのフォトダイ
オード３とが組み合されて成り、シンチレータ２に対し
てＸ線照射側（フォトダイオード３とは逆側）に、３０
Ｗの低圧水銀灯に螢光体として（ＳｒＭｇ）２Ｐ
２Ｏ７：Ｅｕ2+が塗布された退色用光源４を備えてい
る。In FIG. 2, reference numeral 1 denotes an X-ray CT detector,
The scintillator 2 and a photodiode 3 serving as a photoelectric conversion unit are combined to each other, and the scintillator 2 is provided with 30
(SrMg) 2 P as a fluorescent substance for a low-pressure mercury lamp of W
The light source 4 for fading is provided with 2 O 7 : Eu 2+ applied.
シンチレータ２は第１図に示すように、Ｇｄ２Ｏ２Ｓ：
Ｐｒセラミックから成る複数のシンチレータ素子２ａが
接合されて成り、接着剤５によりフォトダイオード３と
接着されている。シンチレータ２の側面２ｂには白色ペ
イント６が塗布され、Ｘ線入射面２ｃには０．２〜０．
５ｍｍ厚さのガラス板７が接着剤８により接着されてい
る。このガラス板７の接着面には、ＴｉＯ２やＳｉＯ２
の薄膜が７０〜１００層積載された誘電体多層膜である
干渉膜９が反射膜として形成されている。As shown in FIG. 1, the scintillator 2 has Gd 2 O 2 S:
A plurality of scintillator elements 2a made of Pr ceramics are bonded together and bonded to the photodiode 3 with an adhesive 5. White paint 6 is applied to the side surface 2b of the scintillator 2, and 0.2 to 0.
A glass plate 7 having a thickness of 5 mm is adhered with an adhesive 8. On the adhesive surface of the glass plate 7, TiO 2 or SiO 2
The interference film 9 which is a dielectric multi-layered film in which 70 to 100 thin films are stacked is formed as a reflective film.
フォトダイオード３は基板１０に取り付けられており、
シンチレータのＸ線入射面２ｃ近傍にはコリメータ１１
が配設され、コリメータ１１を挾持するサポート１２が
基板１０に固着されている。また、２個の退色用光源４
が保持具１３を介してサポート１２に取り付けられてい
る。The photodiode 3 is attached to the substrate 10,
A collimator 11 is provided near the X-ray incidence surface 2c of the scintillator.
And a support 12 for holding the collimator 11 is fixed to the substrate 10. Also, two light sources 4 for fading
Is attached to the support 12 via a holder 13.
上記シンチレータ２，フォトダイオード３，コリメータ
１１，サポート１２及び退色用光源４は内面に光反射剤
として白色ペイントが塗布された遮光箱１４内に収納さ
れており、遮光箱１４のＸ線入射面１４ａにはスリット
としての鉛板１５が設けられている。第３図は退色用光
源４及びコリメータ１１を示す斜視図である。The scintillator 2, the photodiode 3, the collimator 11, the support 12, and the light source 4 for fading are housed in a light-shielding box 14 having an inner surface coated with white paint as a light-reflecting agent. A lead plate 15 as a slit is provided in the. FIG. 3 is a perspective view showing the color fading light source 4 and the collimator 11.
第４図にシンチレータ２の発光スペクトル，退色用光源
４の発光スペクトル及び干渉膜９の透過率を示す。第４
図中ａはシンチレータ２の発光スペクトル，ｂは退色用
光源４の発光スペクトル，ｃ，ｄはそれぞれ入射光の入
射角が０゜，４５゜のときの干渉膜９の透過率を示す。
第４図からわかるように、干渉膜９は約４８０ｎｍを境
にこれより長い波長の光に対しては高反射率（９８％以
上）を有し、かつ、これより短い波長の光に対しては高
透過率（９８％以上）を有する。従って、干渉膜９は退
色用光源４の発生光を透過させ、かつシンチレータ２の
発生光を反射させる機能を有する。FIG. 4 shows the emission spectrum of the scintillator 2, the emission spectrum of the light source 4 for fading, and the transmittance of the interference film 9. Fourth
In the figure, a is the emission spectrum of the scintillator 2, b is the emission spectrum of the light source 4 for fading, and c and d are the transmittances of the interference film 9 when the incident angles of incident light are 0 ° and 45 °, respectively.
As can be seen from FIG. 4, the interference film 9 has a high reflectance (98% or more) for light having a longer wavelength than about 480 nm, and for light having a shorter wavelength. Has a high transmittance (98% or more). Therefore, the interference film 9 has a function of transmitting the light generated by the color fading light source 4 and reflecting the light generated by the scintillator 2.
上記検出器１が設けられたＸ線ＣＴ装置において被写体
の撮影を行う際には、被写体を透過したＸ線（第１，２
図中矢印ｘ）が鉛板１５を介して遮光箱１４内に入射
し、コリメータ１１を介してシンチレータ２を照射す
る。シンチレータ２はこのＸ線の強弱に応じて可視光を
フォトダイオード３に出射し、フォトダイオード３はこ
の可視光に応じた電気信号を映像信号として不図示の画
像構成部へ送る。画像構成部ではこの映像信号に応じて
画像を構成し、不図示の表示部でＣＴ画像が表示され
る。When an object is photographed in the X-ray CT apparatus provided with the detector 1, X-rays (first and second
The arrow x) in the figure enters the light shielding box 14 through the lead plate 15 and irradiates the scintillator 2 through the collimator 11. The scintillator 2 emits visible light to the photodiode 3 according to the intensity of the X-ray, and the photodiode 3 sends an electric signal corresponding to the visible light as a video signal to an image forming unit (not shown). The image composing unit composes an image according to the video signal, and the CT image is displayed on the display unit (not shown).
次に、シンチレータ２の着色部の退色について説明す
る。第５図は上記検出器１と同様のＸ線ＣＴ用検出器に
おいて着色部を生じたシンチレータに光を照射したとき
の光照射量と検出器の感度との関係を示す図である。シ
ンチレータの着色部は光を照射されることにより退色す
る性質があり、第５図に示すように、着色により感度が
低下した検出器は光を照射することにより元の感度に戻
すことができる。Next, the fading of the colored portion of the scintillator 2 will be described. FIG. 5 is a diagram showing the relationship between the light irradiation amount and the sensitivity of the detector when the scintillator having a colored portion is irradiated with light in the X-ray CT detector similar to the detector 1. The colored portion of the scintillator has a property of fading when irradiated with light, and as shown in FIG. 5, a detector whose sensitivity is lowered by coloring can be restored to its original sensitivity by irradiation with light.
そこで、本実施例では、被写体撮影終了後に退色用光源
４の発生光（第１図中矢印ｔ）をシンチレータ２に照射
して、検出器１の感度低下を防止する。このとき退色用
光源４の発生光ｔは上述したようにほとんど干渉膜を透
過するので、効率良くシンチレータ２を照射することが
できる。尚、被写体撮影時には退色用光源４の電源は切
っておく。In view of this, in the present embodiment, the light emitted from the light source 4 for bleaching (arrow t in FIG. 1) is irradiated to the scintillator 2 after the photographing of the object is finished, and the sensitivity of the detector 1 is prevented from lowering. At this time, the generated light t of the color fading light source 4 almost passes through the interference film as described above, so that the scintillator 2 can be efficiently irradiated. The power of the light source 4 for fading is turned off at the time of photographing the subject.
本実施例においては、干渉膜９はシンチレータ２の発生
光に対して高反射率を有するので、被写体撮影時にはシ
ンチレータ２の発生光は干渉膜９及び白色ペイント６で
反射されて、効率良くフォトダイオード３に入射する。
特に、本実施例で反射膜として用いられる干渉膜９（誘
電体多層膜）は、従来反射剤として使用されていた白色
ペイントよりもシンチレータ２の発生光に対して高反射
率を有するので、従来に比べて検出器１の感度を高める
ことができる。In the present embodiment, the interference film 9 has a high reflectance with respect to the light generated by the scintillator 2, so that the light generated by the scintillator 2 is reflected by the interference film 9 and the white paint 6 when the subject is photographed, and the photodiode is efficiently used. It is incident on 3.
In particular, since the interference film 9 (dielectric multilayer film) used as the reflection film in this embodiment has a higher reflectance for the light generated by the scintillator 2 than the white paint conventionally used as the reflection agent, It is possible to increase the sensitivity of the detector 1 as compared with.
また、干渉膜９は退色用光源４の発生光に対しては高透
過率を有するので、退色用光源４の発生光は干渉膜９を
透過して効率良くシンチレータ２に入射し、着色部分の
退色を行うことができる。従って、シンチレータ２の放
射線劣化による検出器１の感度低下を防止することがで
き、その結果、ＣＴ値の変動やアーチファクトの発生を
低減し、表示画像の画質劣化を防止することができる。Further, since the interference film 9 has a high transmittance with respect to the light generated by the light source 4 for fading, the light generated by the light source 4 for fading passes through the interference film 9 and efficiently enters the scintillator 2 so that the colored portion Fading can be performed. Therefore, it is possible to prevent a decrease in the sensitivity of the detector 1 due to radiation deterioration of the scintillator 2, and as a result, it is possible to reduce CT value fluctuations and the occurrence of artifacts, and prevent deterioration of the display image quality.
尚、上記実施例においては、ガラス板７のシンチレータ
２側の面に反射膜としての干渉膜９を形成し、このガラ
ス板７をシンチレータ２のＸ線入射面２ｃに接着した
が、本発明はこれに限定されるものではなく、例えばシ
ンチレータのＸ線入射面に直接反射膜を形成してもよ
い。In the above embodiment, the interference film 9 as a reflection film is formed on the surface of the glass plate 7 on the side of the scintillator 2 and the glass plate 7 is bonded to the X-ray incident surface 2c of the scintillator 2. The present invention is not limited to this, and for example, a reflective film may be formed directly on the X-ray incident surface of the scintillator.
［発明の効果］ 本発明のＸ線ＣＴ用検出器は以上の構成及び作用を有す
るもので、退色用光源から発生した光を反射膜を透過さ
せて効率良くシンチレータに入射させることにより、シ
ンチレータの放射線劣化による検出器の感度低下、すな
わち検出精度の低下を防止し、ＣＴ像を表示する際に
は、ＣＴ値の変動やアーチファクトの発生を低減して、
表示画像画質低下を防止することができる。EFFECTS OF THE INVENTION The X-ray CT detector of the present invention has the above-described structure and action, and allows the light emitted from the light source for bleaching to pass through the reflecting film and efficiently enter the scintillator. It is possible to prevent a decrease in the sensitivity of the detector due to radiation deterioration, that is, a decrease in detection accuracy, and reduce the fluctuation of CT values and the occurrence of artifacts when displaying a CT image.
It is possible to prevent deterioration of the display image quality.
また、反射膜として干渉膜、特に誘電体多層膜を用いれ
ば、反射膜を従来反射剤として使用されている白色ペイ
ントよりシンチレータが発する光に対して高反射率とす
ることができるので、検出器の感度，検出精度を従来よ
り向上させることができる。Further, if an interference film, particularly a dielectric multilayer film, is used as the reflective film, the reflective film can have a higher reflectance for the light emitted by the scintillator than the white paint conventionally used as a reflective agent. It is possible to improve the sensitivity and detection accuracy of the above.
第１図は本発明の一実施例のＸ線ＣＴ用検出器のシンチ
レータ部分の構成を示す縦断面図、第２図は同実施例の
Ｘ線ＣＴ用検出器の全体の構成を示す縦断面図，第３図
は同実施例における退色用光源及びコリメータを示す斜
視図，第４図は同実施例におけるシンチレータの発光ス
ペクトル，退色用光源の発光スペクトル及び干渉膜の透
過率を示す図、第５図はＸ線ＣＴ用検出器のシンチレー
タに光を照射したときの光照射量と検出器の感度との関
係を示す図，第６図は従来例のＸ線ＣＴ用検出器の構成
を示す縦断面図、第７図はＸ線ＣＴ用検出器へのＸ線照
射線量と検出器の感度との関係を示す図，第８図は従来
例のＸ線ＣＴ用検出器の感度劣化を説明するための説明
図である。 １……Ｘ線ＣＴ用検出器、２……シンチレータ ２ｃ……Ｘ線入射面 ３……フォトダイオード（光電変換手段） ４……退色用光源、７……ガラス板 ９……干渉膜（反射膜，誘電体多層膜）FIG. 1 is a vertical sectional view showing the configuration of a scintillator portion of an X-ray CT detector according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view showing the overall configuration of the X-ray CT detector of the same embodiment. FIG. 3 is a perspective view showing a color fading light source and a collimator in the same embodiment, and FIG. 4 is a diagram showing an emission spectrum of a scintillator, a light emission spectrum of a color fading light source and a transmittance of an interference film in the same embodiment. FIG. 5 is a diagram showing the relationship between the light irradiation amount and the sensitivity of the detector when the scintillator of the X-ray CT detector is irradiated with light, and FIG. 6 shows the configuration of the conventional X-ray CT detector. FIG. 7 is a longitudinal sectional view, FIG. 7 is a diagram showing the relationship between the X-ray irradiation dose to the X-ray CT detector and the sensitivity of the detector, and FIG. 8 is an explanation of sensitivity deterioration of the conventional X-ray CT detector. It is explanatory drawing for doing. 1 ... Detector for X-ray CT, 2 ... Scintillator 2c ... X-ray incident surface 3 ... Photodiode (photoelectric conversion means) 4 ... Fading light source, 7 ... Glass plate 9 ... Interference film (reflection) Film, dielectric multilayer film)
Claims (3)
れて成るＸ線ＣＴ用検出器において、 前記シンチレータの放射線劣化による着色部分を退色さ
せるために該シンチレータに光を照射する退色用光源を
備え、該退色用光源が発する光の波長を前記シンチレー
タ素子が発する光の波長とは異ならせ、前記シンチレー
タ素子のＸ線入射面に、前記退色用光源が発する光を透
過させ、かつ前記シンチレータが発する光を反射する反
射膜を形成して成ることを特徴とするＸ線ＣＴ用検出
器。1. An X-ray CT detector comprising a combination of a scintillator and photoelectric conversion means, comprising an bleaching light source for irradiating the scintillator with light in order to bleach a colored portion of the scintillator due to radiation deterioration. , The wavelength of light emitted by the light source for fading is different from the wavelength of light emitted by the scintillator element, the X-ray incident surface of the scintillator element transmits the light emitted by the light source for fading, and is emitted by the scintillator. An X-ray CT detector characterized in that a reflective film for reflecting light is formed.
求項１記載のＸ線ＣＴ用検出器。2. The detector for X-ray CT according to claim 1, wherein the reflection film is an interference film.
する請求項２記載のＸ線ＣＴ用検出器。3. The detector for X-ray CT according to claim 2, wherein the interference film is a dielectric multilayer film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30183989A JPH0619461B2 (en) | 1989-11-22 | 1989-11-22 | X-ray CT detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30183989A JPH0619461B2 (en) | 1989-11-22 | 1989-11-22 | X-ray CT detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03163391A JPH03163391A (en) | 1991-07-15 |
| JPH0619461B2 true JPH0619461B2 (en) | 1994-03-16 |
Family
ID=17901780
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30183989A Expired - Lifetime JPH0619461B2 (en) | 1989-11-22 | 1989-11-22 | X-ray CT detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0619461B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3007430U (en) * | 1994-08-02 | 1995-02-14 | 勝治 渡部 | Harris integrated simple replacement bracket |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100581102B1 (en) | 1998-06-18 | 2006-05-16 | 하마마츠 포토닉스 가부시키가이샤 | Scintillator Panel and Radiation Image Sensor |
| JPWO2008117589A1 (en) * | 2007-03-27 | 2010-07-15 | コニカミノルタエムジー株式会社 | Radiation scintillator panel and radiographic imaging device |
| JP5653829B2 (en) * | 2011-04-25 | 2015-01-14 | 富士フイルム株式会社 | Radiographic apparatus, radiographic system, and radiographic method |
| JPWO2016167334A1 (en) * | 2015-04-16 | 2018-02-08 | 三菱ケミカル株式会社 | Radiation image conversion screen, flat panel detector, radiation detector, and scintillator |
| JP7613214B2 (en) * | 2021-04-02 | 2025-01-15 | 株式会社プロテリアル | Scintillator Structure |
-
1989
- 1989-11-22 JP JP30183989A patent/JPH0619461B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3007430U (en) * | 1994-08-02 | 1995-02-14 | 勝治 渡部 | Harris integrated simple replacement bracket |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03163391A (en) | 1991-07-15 |
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