JPS59207134A - Radiation tomographic apparatus - Google Patents
Radiation tomographic apparatusInfo
- Publication number
- JPS59207134A JPS59207134A JP58083143A JP8314383A JPS59207134A JP S59207134 A JPS59207134 A JP S59207134A JP 58083143 A JP58083143 A JP 58083143A JP 8314383 A JP8314383 A JP 8314383A JP S59207134 A JPS59207134 A JP S59207134A
- Authority
- JP
- Japan
- Prior art keywords
- radiation
- detector
- subject
- correction
- ray
- 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.)
- Pending
Links
- 230000005855 radiation Effects 0.000 title claims description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 10
- 229910052710 silicon Inorganic materials 0.000 claims description 10
- 239000010703 silicon Substances 0.000 claims description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- 238000003325 tomography Methods 0.000 claims description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 3
- 239000010931 gold Substances 0.000 claims description 3
- 229910052737 gold Inorganic materials 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 9
- 239000007789 gas Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Analysing Materials By The Use Of Radiation (AREA)
- Measurement Of Radiation (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は、診断のための医療機器の分野に属し、さらに
詳しくは、放射線透過型である補正用検出器を有する放
射線断層撮影装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention belongs to the field of medical equipment for diagnosis, and more particularly relates to a radiation tomography apparatus having a radiation-transmitting correction detector.
（以下余白） 第１図はＣＴ装置の概略図である。 (Margin below) FIG. 1 is a schematic diagram of a CT apparatus.
先ずＣＴ装置の構成および作用について第１図を参照し
て概説する。ガントリー１及びその内部に収納され／こ
回転架台２の中心部には撮影孔３が形成されており、こ
の撮影孔３内には支持台４に載ｒ＜された被検体５の撮
影部位５ａが支持台４のスライドによジ挿入されるよう
になっている。回転架台２はその駆動機構６によってそ
の中心５の周囲を回転可能になっている。又、回転架台
２には、放射線源例えはＸ線管８と、これに対向し被検
体５を挾む位置に設けられたＸ線検出器９とか取付けら
れており、Ｘ線管８よりの出力Ｘ線は、撮影部位５ａを
含む撮影領域７を透過してＸ線検出器９に入射するよう
になっている。ここで、Ｘ線管８より出力されるＸ１８
ｂは図示左右方向に広がりを不する扇形状ビームとなっ
ており、これに対応してＸ線検出器９も、全体が弧状を
成し、前記Ｘ線ビーム８ｂを任意の角度毎に分割し各小
角度内のビームの強度をそれぞれ独立に測定できるよう
に、多部ｔに分割配置されたセルＤＩ ＝ Ｄｎによっ
て構成さｎている。First, the configuration and operation of the CT apparatus will be outlined with reference to FIG. A photographing hole 3 is formed in the center of the gantry 1 and the rotating mount 2 housed therein, and within this photographing hole 3 is a photographed region 5a of a subject 5 placed on a support base 4. is adapted to be inserted into the slide of the support base 4. The rotating pedestal 2 is rotatable around its center 5 by its drive mechanism 6. Furthermore, a radiation source, for example an X-ray tube 8, and an X-ray detector 9, which is placed opposite to this and sandwiching the subject 5, are attached to the rotating mount 2. The output X-rays are configured to pass through an imaging region 7 including the imaging region 5a and enter the X-ray detector 9. Here, X18 output from the X-ray tube 8
b is a fan-shaped beam that does not spread in the horizontal direction shown in the figure, and correspondingly, the X-ray detector 9 also has an arc shape as a whole, and divides the X-ray beam 8b into arbitrary angles. It is composed of cells DI = Dn divided into multiple parts so that the intensity of the beam within each small angle can be measured independently.
ところで、ｎＪ述のようなＣＴ装置においては、各小角
度毎のＸ線ビームの強度の変化は直接画像の画質の悪化
につながり、結果として診断能の低下をもたらすことに
なる。そこで、前Ｒ２Ｘ線の強度を検出し、この検出情
報に基ついて補正を行い、画質の悪化を防止しようとす
る試みかなされている。このような補正方法としては第
２図（ａ）及び（ｂ）に示すようなものが考えられてい
る。即ち、同図（ａ）は、Ｘ線管８の側部方向（Ｘ線ビ
ーム８ｂを、連断しない方向）に補正用検出器１０を配
置し、Ｘ線強度をモニターする方法であり、同図（ｂ）
は検出器９の両端のセルＤ１とＤｎに入射するＸ線が通
常、被検体を通過しないように配置しておき、このセル
で検出される信号を補正情報として使用する方法である
。しかしながら、第２図（ａ）に示す方法では実際に被
検体を透過する中央部のＸ線ビームを検出できないため
、補正箱度が低いという欠 点があった０又、通常
Ｘ線管８としては回転陽極型Ｘ線管が使用されておジ、
陽極が高速回転するのでｖｊ極の振動や回転位置によっ
ては強度分布曲線が第３図に示すように１１〜１３の如
く変化する（製造上のバラツキに基づくものと思われる
）ことが確認されている。従って第２図（ｂ）の如き方
法によっても被検体を透過するＸ線の強度を正確にネ山
正することはできな〃ムつた。By the way, in a CT apparatus such as that described in nJ, changes in the intensity of the X-ray beam for each small angle directly lead to deterioration of image quality, resulting in a deterioration of diagnostic performance. Therefore, attempts have been made to detect the intensity of the front R2 X-rays and perform correction based on this detected information to prevent the image quality from deteriorating. As such a correction method, methods as shown in FIGS. 2(a) and 2(b) have been considered. That is, FIG. 3(a) shows a method of arranging the correction detector 10 in the side direction of the X-ray tube 8 (in a direction that does not disconnect the X-ray beam 8b) and monitoring the X-ray intensity. Figure (b)
This is a method in which the cells D1 and Dn at both ends of the detector 9 are arranged so that the X-rays incident on them do not normally pass through the subject, and the signals detected by these cells are used as correction information. However, the method shown in Fig. 2(a) has the drawback of low correction accuracy because it cannot detect the central X-ray beam that actually passes through the object. A rotating anode X-ray tube is used.
Since the anode rotates at high speed, it has been confirmed that the intensity distribution curve changes as shown in Figure 3, depending on the vibration and rotational position of the vj pole (this is thought to be due to manufacturing variations). There is. Therefore, even with the method shown in FIG. 2(b), it is not possible to accurately correct the intensity of the X-rays passing through the object.
本発明は前記事情に鑑みてなさ牡たものであり、Ｘ線の
強度を正確に補正できる機能をΦ１ａえたＣＴ装置を提
供することによシ画質の向上及び診断能の向上を図るこ
とを目的とするものである。The present invention was developed in view of the above circumstances, and an object of the present invention is to improve image quality and diagnostic ability by providing a CT apparatus that has a function of Φ1a that can accurately correct the intensity of X-rays. That is.
前記目的を達成するための本発明の概妥は前記放射線源
と被検体との間に前記扇形状の放射線と交差する方向に
配置されたシリコン層とその両面に蒸着形成された一対
の電極とから成る補正用検出器を具備し、被検体到達前
の放射線強度を測定して得られたデータに基づいてＡｉ
ｌ記透過放射線に基づくデータを補正することを特徴と
するものである。The outline of the present invention for achieving the above object includes a silicon layer disposed between the radiation source and the subject in a direction intersecting the fan-shaped radiation, and a pair of electrodes formed by vapor deposition on both sides of the silicon layer. Based on the data obtained by measuring the radiation intensity before reaching the subject, the Ai
The present invention is characterized by correcting data based on transmitted radiation.
以下実施例により本発明を具体的に説明する０第４図（
ａｔ ｒ （ｂ）は本発明の一実施例を示す説明図であ
る。図中８は扇形状に広がるＸ線ビーム８ｂを出力する
Ｘ線管でおる。このＸ線ビーム８ｂの前方には実際にＸ
線検出器９のセル］）１−Ｄｎに入射するＸ線ビーム８
ｂの全域にわたり透過させる位置にＸ線透過型の補正用
検出器２０が設けられている。したがって、Ｘ線検出器
９に入射するＸ線ビーム（被検体５及び寝台４を介して
入射するＸ線ビームも含める）は、すべて補正用検出器
２０を透過したものである。The present invention will be specifically explained with reference to examples below.
at r (b) is an explanatory diagram showing one embodiment of the present invention. In the figure, 8 is an X-ray tube that outputs an X-ray beam 8b that spreads in a fan shape. There is actually an X-ray in front of this X-ray beam 8b.
Cell of ray detector 9]) X-ray beam 8 incident on 1-Dn
An X-ray transmission type correction detector 20 is provided at a position that transmits light over the entire area b. Therefore, all of the X-ray beams that enter the X-ray detector 9 (including the X-ray beams that enter through the subject 5 and bed 4) have passed through the correction detector 20.
この補正用検出器２０の構造を第５図に示す。The structure of this correction detector 20 is shown in FIG.
第５図は補正用検出器２０の概略斜視断面図である。同
図に示すように補正用検出器２０はシリコン（Ｓｉ）層
（厚さＬａ＝０．０２ａ＋程肛）の両面に、金蒸着層（
厚さＬｌ＝〜１００Ｘ）１７及びアルミ蒸着層（厚さＬ
２ ＝〜１００Ｘ）１９を蒸着することによシ形成され
、前記金蒸着層１７とアルミ蒸着層１９とを一対の電極
とすることにより、Ｘ線ビームが矢印Ｘ方向に透過する
除に生じる電位差を取り出すことができる。補正用検出
器２０はこのように構造上極めて薄いためスペースを要
さず、また補正用信号として十分なＸａ検出が可能であ
って、Ｘ線ビーム透過の際の吸収率は極めて低い（アル
ミニウム当量にして１０分の教訓＋８反にすることは容
易でちる）。FIG. 5 is a schematic perspective sectional view of the correction detector 20. As shown in the figure, the correction detector 20 has a gold vapor-deposited layer (
Thickness Ll=~100X) 17 and aluminum vapor deposition layer (thickness L
2 = ~100 can be taken out. Since the correction detector 20 is extremely thin in structure, it does not require space, and is capable of detecting sufficient Xa as a correction signal, and has an extremely low absorption rate (aluminum equivalent (It's easy to make it 10 minutes of lessons + 8 lessons).
このような補正用検出器２０の電極１７，１９から取シ
出される電位差はＡ／Ｄ（アナログ・ディジタル）変換
手段１４においてディジタル信号に変換され、後段に配
置された補正手段１５に入力する。また同様にＸ線検出
器９の出力信号もψ変換手段１４を介して補正十段工５
に入力する。The potential difference taken out from the electrodes 17 and 19 of the correction detector 20 is converted into a digital signal by an A/D (analog/digital) conversion means 14, and inputted to a correction means 15 disposed at a subsequent stage. Similarly, the output signal of the X-ray detector 9 is also transmitted through the ψ conversion means 14 to the correction stage 5.
Enter.
補正手段１５は前記補正用検出器２０からのＸ線強度に
基づいてＸ線検出器９から出力される画像再構成用原デ
ータを補正し、補正された画像再構成川原ｒ−夕は後段
に配置される画像再構成手段１６において、画像の再構
成がなされる。The correction means 15 corrects the original data for image reconstruction output from the X-ray detector 9 based on the X-ray intensity from the correction detector 20, and the corrected image reconstruction Kawahara r-Yu is sent to a subsequent stage. The image is reconstructed in the image reconstruction means 16 arranged therein.
このように、実際にＸ線検出器９に入射するＸ線ビーム
の全域にわたジその強度をＸａ透過型検出器であるシリ
コン検出器２０によって直接測定し、その結果を補正情
報として使用するため補正精度が極めて向上する。In this way, the intensity of the X-ray beam actually incident on the X-ray detector 9 is directly measured over the entire area by the silicon detector 20, which is an Xa transmission type detector, and the result is used as correction information. Correction accuracy is greatly improved.
また、前記補正用検出器として、例えばガス封入容器内
にキセノンガス、アルゴンガス、クリゾトンガス等を封
入し、更に高圧電極板に数１００ボルトの高電圧を印加
し、Ｘ線ビームが透過する際の電離作用を利用して信号
電極板により透過するＸ線強度を検出するような従来の
透過型検出器も使用できるが、次の点でシリコン検出器
の方が優れている。すなわち、従来の透過型検出器はガ
ス封入容器及びガス自体でのＸ線吸収が多いがシリコン
検出器はＸ線吸収が極めて少ない。ｉた従来の検出器は
高電圧の印加が不可欠であるがシリコン検出器は不要で
ある。更に従来の検出器はその構造上検出器自体の外形
が大きくなるが、シリコン検出器は、検出器自体が極め
て薄いためスペースをとらない。In addition, as the correction detector, for example, xenon gas, argon gas, chryzoton gas, etc. is sealed in a gas-filled container, and a high voltage of several hundred volts is applied to a high-voltage electrode plate, so that the A conventional transmission type detector that uses ionization to detect the intensity of X-rays transmitted by a signal electrode plate can also be used, but a silicon detector is superior in the following respects. That is, while conventional transmission type detectors absorb a lot of X-rays in the gas-filled container and the gas itself, silicon detectors absorb very little X-rays. Conventional detectors require the application of high voltage, but silicon detectors do not. Furthermore, while conventional detectors have a large external shape due to their structure, silicon detectors do not take up much space because they are extremely thin.
以上詳述した本発明によれは、Ｘａ検出器及び補正用検
出器それぞれにおけるＸ線ビームの変動量は全く同一と
なるためＸ線の強度を正確に補正できる機能を備えたＣ
Ｔ装置を提供することができる。したがって、このＣＴ
装置によれば再構成画像の画質の向上及び診断能の向上
を図ることができる。According to the present invention described in detail above, since the amount of fluctuation of the X-ray beam in each of the Xa detector and the correction detector is exactly the same, the C
T device can be provided. Therefore, this CT
According to the apparatus, it is possible to improve the image quality of reconstructed images and to improve diagnostic performance.
第１図はＣＴ装置の概略説明図、第２図（ａ） 、 （
ｂ）は従来の強度補正態様の説明図、第３図は強度分布
曲線の変化を示す図、第４図（ａ） ｐ （ｂ）は本発
明の一実施例を説明するための概略図であって、（ａ）
はＸ線ビームのファン方向から見た図、（ｂ）はＸ線ビ
ームのスライス方向から見た図、第５図は本発明に適用
される補正用検出器の構成を説明するための概略図であ
る。
４・・・寝台、５・・・被検体、８・・・Ｘａ管、９・
・・Ｘ線検出器、１４・・・Ａ／Ｄ変換手段、１５・・
・補正手段、１６・・・画像再構成手段、１７・・・電
極（金蒸着層）、１８・・・シリコン層、１９・・・電
極（アルミ蒸着）＠）、２０・・・補正用検出器。
第２図
ｅ□
第 ４ 図Figure 1 is a schematic explanatory diagram of the CT apparatus, Figure 2 (a), (
b) is an explanatory diagram of the conventional intensity correction mode, FIG. 3 is a diagram showing changes in the intensity distribution curve, and FIGS. 4(a) and 4(b) are schematic diagrams for explaining one embodiment of the present invention. Yes, (a)
5 is a diagram seen from the fan direction of the X-ray beam, (b) is a diagram seen from the slice direction of the X-ray beam, and FIG. 5 is a schematic diagram for explaining the configuration of the correction detector applied to the present invention. It is. 4... Bed, 5... Subject, 8... Xa tube, 9...
...X-ray detector, 14...A/D conversion means, 15...
- Correction means, 16... Image reconstruction means, 17... Electrode (gold vapor deposited layer), 18... Silicon layer, 19... Electrode (aluminum vapor deposited) @), 20... Detection for correction vessel. Figure 2 e□ Figure 4
Claims (2)
射し、その際に得られる透過放射線に基づくデータをコ
ンピュータにより画像再構成処理して被検体の断層像を
得るようにした放射線断層撮影装置において、前記放射
線源と被検体との間に前記扇形状の放射線と交差する方
向に配置されたシリコン層とその両面に蒸着形成された
一対の電極上から成る補正用検出器を具備し、被検体到
達前の放射線強度を測定して得られたデータに基づいて
前記透過放射線に基づくデータを補正することを特徴と
する放射線断層撮影装置。(1) Radiation that emits fan-shaped radiation from a radiation source toward the subject, and uses a computer to perform image reconstruction processing on data based on the transmitted radiation obtained at that time to obtain a tomographic image of the subject. The tomography apparatus includes a correction detector comprising a silicon layer disposed between the radiation source and the subject in a direction intersecting the fan-shaped radiation, and a pair of electrodes deposited on both sides of the silicon layer. A radiation tomography apparatus characterized in that data based on the transmitted radiation is corrected based on data obtained by measuring radiation intensity before reaching the subject.
ニウム蒸着層とから成ることを特徴とする特許請求の範
囲第１項記載の放射線断層撮影装置。(2) The radiation tomography apparatus according to claim 1, wherein each of the pair of electrodes comprises a gold vapor-deposited layer and an aluminum vapor-deposited layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58083143A JPS59207134A (en) | 1983-05-11 | 1983-05-11 | Radiation tomographic apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58083143A JPS59207134A (en) | 1983-05-11 | 1983-05-11 | Radiation tomographic apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS59207134A true JPS59207134A (en) | 1984-11-24 |
Family
ID=13793987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58083143A Pending JPS59207134A (en) | 1983-05-11 | 1983-05-11 | Radiation tomographic apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59207134A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005524454A (en) * | 2002-05-03 | 2005-08-18 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | X-ray inspection equipment including dosimeter |
| JP2011022030A (en) * | 2009-07-16 | 2011-02-03 | Yokogawa Electric Corp | Radiation inspection apparatus |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55142263A (en) * | 1979-04-24 | 1980-11-06 | Toshiba Corp | Semiconductor radiant ray detector |
| JPS561144A (en) * | 1979-06-15 | 1981-01-08 | Tokyo Shibaura Electric Co | Radiation tomographing device |
| JPS5683333A (en) * | 1979-12-11 | 1981-07-07 | Hitachi Medical Corp | Ct apparatus |
-
1983
- 1983-05-11 JP JP58083143A patent/JPS59207134A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55142263A (en) * | 1979-04-24 | 1980-11-06 | Toshiba Corp | Semiconductor radiant ray detector |
| JPS561144A (en) * | 1979-06-15 | 1981-01-08 | Tokyo Shibaura Electric Co | Radiation tomographing device |
| JPS5683333A (en) * | 1979-12-11 | 1981-07-07 | Hitachi Medical Corp | Ct apparatus |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005524454A (en) * | 2002-05-03 | 2005-08-18 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | X-ray inspection equipment including dosimeter |
| JP2011022030A (en) * | 2009-07-16 | 2011-02-03 | Yokogawa Electric Corp | Radiation inspection apparatus |
| US8447012B2 (en) | 2009-07-16 | 2013-05-21 | Yokogawa Electric Corporation | Radiation inspection apparatus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4686695A (en) | Scanned x-ray selective imaging system | |
| US4672649A (en) | Three dimensional scanned projection radiography using high speed computed tomographic scanning system | |
| US4472822A (en) | X-Ray computed tomography using flying spot mechanical scanning mechanism | |
| JP3128634B2 (en) | Simultaneous transmission and emission focused tomography | |
| US6694172B1 (en) | Fault-tolerant detector for gamma ray imaging | |
| US4709382A (en) | Imaging with focused curved radiation detectors | |
| JPH0725923Y2 (en) | Computer tomograph | |
| JP2002514772A (en) | Multi-purpose multi-density multi-atomic number detector media | |
| EP1397700A1 (en) | Diagnostic imaging system comprising a source of penetrating radiation and also a radiopharmaceutical source injected into the subject | |
| JP2002148340A (en) | Diagnostic image forming nuclear medicine gamma ray camera and diagnostic image forming method by using it | |
| JP5283382B2 (en) | Nuclear medicine detector | |
| US6661865B1 (en) | Variable axial shielding for pet imaging | |
| US4559639A (en) | X-Ray detector with compensation for height-dependent sensitivity and method of using same | |
| GB1602521A (en) | Arrangement for producing an image of a body section using gamma or x-radiation | |
| JPH06254082A (en) | Device and method for photographing radiation stereoscopic image | |
| US5680427A (en) | Normalization of tomographic image data | |
| US6429433B1 (en) | Continuous rotation sampling scheme for transmission radiation corrected gamma cameras | |
| JPS59207134A (en) | Radiation tomographic apparatus | |
| JP4114467B2 (en) | X-ray CT system | |
| GB2074415A (en) | Computed tomography with selectable image resolution | |
| Zoltani et al. | Flash x‐ray computed tomography facility for microsecond events | |
| JPH0620488Y2 (en) | X-ray CT system | |
| JP3763165B2 (en) | SPECT absorption correction method | |
| JP2000040478A (en) | X-ray tube device | |
| US20160245932A1 (en) | Radiation detector and detection method having reduced polarization |