JP2002243662A - X-ray ct equipment - Google Patents
X-ray ct equipmentInfo
- Publication number
- JP2002243662A JP2002243662A JP2001033581A JP2001033581A JP2002243662A JP 2002243662 A JP2002243662 A JP 2002243662A JP 2001033581 A JP2001033581 A JP 2001033581A JP 2001033581 A JP2001033581 A JP 2001033581A JP 2002243662 A JP2002243662 A JP 2002243662A
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- Prior art keywords
- ray
- collimator
- opening
- pair
- subject
- 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.)
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- Analysing Materials By The Use Of Radiation (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、産業用のＸ線ＣＴ
装置、特に物体の微細な内部構造を非破壊で検査するの
に好適なＸ線ＣＴ装置に関するものである。The present invention relates to an industrial X-ray CT.
The present invention relates to an X-ray CT apparatus suitable for nondestructively inspecting a fine internal structure of an object.
【０００２】[0002]
【従来の技術】Ｘ線ＣＴ装置は、外部から生体内部の組
織を観察することができるので、従来から、医療用とし
て広く用いられている。また、Ｘ線ＣＴ装置は、金属や
セラミックス、その他の複合材料等の内部の欠陥や、そ
れらの材料からなる構造物の内部の様子（構造形状や材
質の変化）等を非破壊で検査することもできるので、近
年、産業用としても多用されつつある。2. Description of the Related Art An X-ray CT apparatus has been widely used for medical purposes since it can observe a tissue inside a living body from the outside. In addition, X-ray CT systems must inspect nondestructively for internal defects such as metals, ceramics, and other composite materials, and for the internal appearance of structures (changes in structural shape and materials) made of such materials. In recent years, it has been widely used for industrial purposes.
【０００３】このようなＸ線ＣＴ装置は、図４に示すよ
うに、被検体４１を挟んで対向配置されたＸ線源４２及
びＸ線検出器４３が一体となって被検体４１の周囲を相
対的に回転しつつ（矢印イ参照）、Ｘ線源４２から扇状
のＸ線ビーム４４を放射する。これにより、被検体４１
を透過したＸ線の強さに応じた電気信号が多数、Ｘ線検
出器４３から出力されるが、この出力信号に基づいて得
られた多数のＸ線投影データに画像再構成処理を施すこ
とで、被検体４１の断面像（ＣＴ画像）を得るように構
成されている。In such an X-ray CT apparatus, as shown in FIG. 4, an X-ray source 42 and an X-ray detector 43 which are opposed to each other with a subject 41 interposed therebetween are integrated so as to surround the subject 41. The X-ray source 42 emits a fan-shaped X-ray beam 44 while rotating relatively (see arrow A). Thereby, the subject 41
A large number of electric signals corresponding to the intensity of the X-rays transmitted through are output from the X-ray detector 43. The image reconstruction processing is performed on a large number of X-ray projection data obtained based on the output signals. Thus, a cross-sectional image (CT image) of the subject 41 is obtained.
【０００４】Ｘ線ＣＴ装置においては、Ｘ線検出器４３
を構成するＸ線検出素子４３ａがＸ線源４２を臨む後述
開口の幅（開口幅）が小さいほど、空間分解能の高い断
面像が得られる。しかし、Ｘ線検出素子４３ａの開口幅
を小さくすると、その素子４３ａに入射するＸ線量が減
少し、ノイズの多い画像となるので、鮮明な画像を再構
成できる被検体４１の大きさ（Ｘ線透過方向の寸法）は
ある値以下に制限されてしまう。In an X-ray CT apparatus, an X-ray detector 43
The smaller the width (opening width) of an opening described later in which the X-ray detecting element 43a constituting the X-ray source 42 faces the X-ray source 42, the higher the cross-sectional image with higher spatial resolution can be obtained. However, when the opening width of the X-ray detecting element 43a is reduced, the amount of X-rays incident on the element 43a decreases, and an image with much noise is generated. Therefore, the size of the subject 41 (X-ray (Dimension in the transmission direction) is limited to a certain value or less.
【０００５】またＸ線ＣＴ装置は、図５に示すように、
ある厚み（スライス幅５１）をもったＸ線ビーム４４ａ
の被検体４１の平均透過量として被検体断面を画像化す
るため、Ｘ線ビーム４４ａの厚み寸法の範囲内での構造
（形状，材質等）の変化は画像化されず、そこでの変化
部分は単にぼけた画像となるだけである。[0005] Further, as shown in FIG.
X-ray beam 44a having a certain thickness (slice width 51)
Since the cross section of the subject is imaged as the average transmission amount of the subject 41, the change of the structure (shape, material, etc.) within the range of the thickness dimension of the X-ray beam 44a is not imaged, and the changed portion there is It simply results in a blurred image.
【０００６】したがって、上記構造変化を画像化可能に
スライス幅（断面厚さ）５１を変化させるため、Ｘ線検
出器４３のＸ線入射側にはコリメータ５２が設置され
る。特に、スライス幅５１方向の微細な構造変化を画像
化したい場合には、スライス幅５１、換言すればＸ線検
出素子４３ａ（図４参照）がＸ線源４２を臨む開口５３
の高さを小さくするコリメータ５２が設置される。な
お、Ｘ線源４２の出射側のコリメータ５４は、被検体４
１への照射Ｘ線の整形用コリメータである。しかし、開
口５３の高さ（開口高さ）も、上記開口幅の場合と同様
に、小さくするとＸ線検出素子４３ａに入射するＸ線量
が減少し、ノイズの多い画像となってしまう。Accordingly, a collimator 52 is provided on the X-ray incident side of the X-ray detector 43 in order to change the slice width (cross-sectional thickness) 51 so that the structural change can be imaged. In particular, when it is desired to image a minute structural change in the direction of the slice width 51, the slice width 51, in other words, the X-ray detecting element 43a (see FIG. 4) has an aperture 53 facing the X-ray source.
A collimator 52 is provided to reduce the height of the collimator. The collimator 54 on the emission side of the X-ray source 42 is
1 is a collimator for shaping the irradiated X-rays to 1. However, when the height of the opening 53 (opening height) is reduced as in the case of the above-described opening width, the amount of X-rays incident on the X-ray detection element 43a decreases, resulting in a noisy image.
【０００７】そこで、大きさ（Ｘ線透過方向の寸法）や
スライス幅方向の構造変化の程度の異なる広範囲の被検
体４１について、空間分解能が高く、ぼけやノイズの少
ない画像を得るためには、上記開口幅や開口高さ（スラ
イス幅５１）を変化させ得ることが条件となる。Therefore, in order to obtain an image with high spatial resolution and little blur and noise for a wide range of subjects 41 having different sizes (dimensions in the X-ray transmission direction) and structural changes in the slice width direction, The condition is that the opening width and the opening height (slice width 51) can be changed.
【０００８】このうち、ぼけの少ない画像を得ることに
ついては、例えば特開平３−２０９１１７号公報に記載
され、あるいは図６に例示するように、スライス幅５１
（開口高さｈ）を可変としたコリメータ６１を用いるこ
とで解決していた。すなわち、被検体４１（図４参照）
のスライス幅方向の構造変化に応じてスライス幅５１を
適宜変化させることで、ぼけが少なく、かつノイズも少
ない画像を得ていた。Among them, obtaining an image with less blur is described in, for example, JP-A-3-209117, or as shown in FIG.
The problem has been solved by using a collimator 61 having a variable (opening height h). That is, the subject 41 (see FIG. 4)
By appropriately changing the slice width 51 according to the structural change in the slice width direction, an image with less blur and less noise was obtained.
【０００９】[0009]
【発明が解決しようとする課題】しかし、断面像の空間
分解能を適宜変化させること、換言すればＸ線検出素子
４３ａの開口幅を可変にすることは、元々Ｘ線検出器４
３におけるＸ線検出素子４３ａの配列が稠密になされて
いる関係上、著しく困難であった。例えば、特開平５−
３０９０８８号公報には、微細なスリット（開口幅）を
作ることのできるＸ線ＣＴ装置のコリメータが開示され
ているが、このスリットはコリメータ設置状態において
変化させ得るものではなかった。However, to appropriately change the spatial resolution of the cross-sectional image, in other words, to make the opening width of the X-ray detecting element 43a variable, originally, the X-ray detector 4 is required.
3 was extremely difficult because of the dense arrangement of the X-ray detecting elements 43a. For example, Japanese Patent Application Laid-Open
Japanese Patent No. 309088 discloses a collimator of an X-ray CT apparatus capable of forming a fine slit (opening width), but this slit cannot be changed in a state where the collimator is installed.
【００１０】したがって、Ｘ線検出素子４３ａの開口幅
を被検体４１に応じて変える場合には、所望の開口幅に
設定されたコリメータに交換しなけばならず、逆に、コ
リメータを交換しない限り、鮮明な画像を再構成できる
被検体４１の大きさが制限されるという関係にあった。Therefore, when changing the opening width of the X-ray detecting element 43a in accordance with the subject 41, the collimator must be replaced with a collimator set to a desired opening width. In addition, the size of the subject 41 that can reconstruct a clear image is limited.
【００１１】また、断面像を精度よく再構成させるため
には、図７に示すように、コリメータ７１の開口寸法
を、開口幅ｗ＝開口高さｈ（スライス幅５１）とするの
が理想的であり、従来から、このようなコリメータ７１
を設置したＸ線ＣＴ装置もあった。しかし、図７に示す
コリメータ７１の開口寸法も、予め設定された値に固定
されているもので、したがって、このようなコリメータ
７１によっても、ノイズが少なく、精度のよい画像を再
構成できる被検体４１の大きさは制限されてしまった。In order to accurately reconstruct a cross-sectional image, it is ideal that the opening size of the collimator 71 is set to the opening width w = the opening height h (slice width 51) as shown in FIG. Conventionally, such a collimator 71
There was also an X-ray CT apparatus equipped with. However, the opening size of the collimator 71 shown in FIG. 7 is also fixed to a preset value. Therefore, even with such a collimator 71, an object with little noise and an accurate image can be reconstructed. The size of 41 has been limited.
【００１２】本発明は、上記のような実情に鑑みなされ
たもので、大きさ（Ｘ線透過方向の寸法）やスライス幅
方向の構造変化の程度の異なる広範囲の被検体につい
て、空間分解能が高く、ぼけやノイズも少なく、更に精
度のよい断面像を得ることのできるＸ線ＣＴ装置を提供
することを目的とする。The present invention has been made in view of the above situation, and has a high spatial resolution for a wide range of subjects having different sizes (dimensions in the X-ray transmission direction) and structural changes in the slice width direction. It is an object of the present invention to provide an X-ray CT apparatus which can obtain a more accurate cross-sectional image with less blur and noise.
【００１３】[0013]
【課題を解決するための手段】上記目的を達成するため
に、請求項１に記載の発明は、Ｘ線源が被検体の周囲を
相対的に回転しつつＸ線を照射することでＸ線検出器か
ら出力される、前記被検体の周囲多方向からの透過Ｘ線
に基づく信号から多数のＸ線投影データを得て画像再構
成処理し、前記被検体の断面像を得るＸ線ＣＴ装置にお
いて、一対のコリメータブロックを前記Ｘ線検出器のＸ
線入射側に配してなり、前記Ｘ線検出器のＸ線検出素子
が前記Ｘ線源を臨む、前記一対のコリメータブロックで
形成される開口の幅及び高さ寸法が、当該一対のコリメ
ータブロックの少なくともいずれか一方の進退に応じて
縮小，拡大自在のコリメータを具備することを特徴とす
る。In order to achieve the above object, according to the first aspect of the present invention, an X-ray source emits X-rays while relatively rotating around a subject. An X-ray CT apparatus that obtains a large number of X-ray projection data from signals based on transmitted X-rays from multiple directions around the subject output from a detector and performs image reconstruction processing to obtain a cross-sectional image of the subject , A pair of collimator blocks is connected to the X-ray detector X
The width and height dimensions of the opening formed by the pair of collimator blocks are arranged on the line incident side, and the X-ray detection element of the X-ray detector faces the X-ray source. And a collimator that can be reduced or enlarged in accordance with at least one of the forward and backward movements.
【００１４】請求項２に記載の発明は、請求項１に記載
の発明において、一対のコリメータブロックは、Ｘ線検
出器のＸ線入射側の前後方向に置かれ、対向面相互が近
接した又は擦り合った状態で上下側から進退自在で、前
記Ｘ線検出器のＸ線検出素子がＸ線源を臨む開口の内壁
面を形成する端面が各々断面鋸歯状に形成され、それら
鋸歯状端面の谷面相互が前記開口側から見て向かい合っ
た状態で上下側から進退することで、当該谷面相互で囲
まれて形成される開口の幅及び高さ寸法が連動して縮
小，拡大されることを特徴とする。According to a second aspect of the present invention, in the first aspect, the pair of collimator blocks are disposed in the front-rear direction on the X-ray incident side of the X-ray detector, and the opposing surfaces are close to each other. The X-ray detectors of the X-ray detector are capable of moving back and forth from the upper and lower sides in a rubbed state, and the end faces forming the inner wall surface of the opening facing the X-ray source are each formed in a sawtooth cross section. The widths and heights of the openings formed between the valley surfaces are reduced and enlarged in conjunction with each other by moving back and forth from above and below with the valley surfaces facing each other as viewed from the opening side. It is characterized by.
【００１５】[0015]
【発明の実施の形態】以下、本発明の実施の形態を図面
に基づき説明する。図１は、本発明によるＸ線ＣＴ装置
の一実施形態の要部を示す平面図である。図示するよう
に、被検体４１を挟んだ対向位置には、Ｘ線源４２及び
Ｘ線検出器４３が配置される。Ｘ線源４２は、被検体４
１の周囲を相対的にほぼ３６０°回転可能であり（矢印
イ参照）、また、回転中に連続的又は間欠的にＸ線ビー
ム４４を放射可能に構成されている。Ｘ線検出器４３
は、被検体４１を透過したＸ線の強さに応じた電気信号
を出力可能に構成されている。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a main part of an embodiment of an X-ray CT apparatus according to the present invention. As shown in the figure, an X-ray source 42 and an X-ray detector 43 are arranged at positions facing each other across the subject 41. The X-ray source 42 is
1 is relatively rotatable about 360 ° (see arrow A), and the X-ray beam 44 can be emitted continuously or intermittently during rotation. X-ray detector 43
Is configured to be able to output an electric signal corresponding to the intensity of the X-ray transmitted through the subject 41.
【００１６】処理装置（図示せず）は、Ｘ線検出器４３
から出力される、被検体４１の周囲多方向からの透過Ｘ
線に基づく信号から得られた多数のＸ線投影データに画
像再構成処理を施し、被検体４１の断面像（ＣＴ画像）
を得るように構成されている。A processing device (not shown) includes an X-ray detector 43.
Transmitted from multiple directions around the subject 41
Image reconstruction processing is performed on a large number of X-ray projection data obtained from a line-based signal, and a sectional image (CT image) of the subject 41
Are configured to obtain
【００１７】なお図１は、本発明を、いわゆる第３世代
（Ｒotate/Ｒotate方式）のＸ線ＣＴ装置に適用した場
合を例示している。したがって、Ｘ線源４２及びＸ線検
出器４３は、一体となって被検体４１の周囲を相対的に
回転可能になされ、また、Ｘ線ビームとしては扇状Ｘ線
ビーム４４が用いられ、Ｘ線検出器４３は多数のＸ線検
出素子４３ａが円弧状に配列されてなる。FIG. 1 shows an example in which the present invention is applied to a so-called third-generation (Rotate / Rotate system) X-ray CT apparatus. Therefore, the X-ray source 42 and the X-ray detector 43 are integrally rotatable around the subject 41, and a fan-shaped X-ray beam 44 is used as the X-ray beam. The detector 43 has a large number of X-ray detection elements 43a arranged in an arc shape.
【００１８】ここで、本発明においては、Ｘ線検出器４
３のＸ線入射側に一対のコリメータブロック１１ａ，１
１ｂからなるコリメータ１１が配設されている。一対の
コリメータブロック１１ａ，１１ｂは、Ｘ線検出素子４
３ａがＸ線源４２を臨む、当該一対のコリメータブロッ
ク１１ａ，１１ｂで形成される開口１２の幅及び高さの
寸法が、少なくともいずれか一方のコリメータブロック
１１ａ又は１１ｂの進退に応じて縮小，拡大自在に構成
されている。Here, in the present invention, the X-ray detector 4
3, a pair of collimator blocks 11a, 1
A collimator 11 composed of 1b is provided. The pair of collimator blocks 11a and 11b
The dimension of the width and height of the opening 12 formed by the pair of collimator blocks 11a and 11b in which the 3a faces the X-ray source 42 is reduced or enlarged in accordance with at least one of the collimator blocks 11a and 11b. It is freely configured.
【００１９】以下に、コリメータ１１の具体例を詳述す
る。図２は、図１中のコリメータ１１及びＸ線検出器４
３部分の一部を取り出して示す図で、（ａ）はコリメー
タ正面側から見た図、（ｂ）は（ａ）図の右側方から見
た図である。図３は、図２中からコリメータを取り出
し、分解して示す斜視図である。なお、図２，図３にお
いて、図１と同一符号は同一又は相当部分を示す。Hereinafter, a specific example of the collimator 11 will be described in detail. FIG. 2 shows the collimator 11 and the X-ray detector 4 in FIG.
FIGS. 3A and 3B are diagrams illustrating a part of the three parts, in which FIG. 3A is a view as viewed from the front side of the collimator, and FIG. 3B is a view as viewed from the right side of FIG. FIG. 3 is a perspective view showing the collimator taken out of FIG. 2 and disassembled. 2 and 3, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.
【００２０】図２に示すように、一対のコリメータブロ
ック１１ａ，１１ｂは、Ｘ線検出器４３のＸ線入射側の
前後方向に配置され、対向面相互が近接した又は擦り合
った状態で上下相反する側から進退自在である（矢印
ロ，ハ参照）。また、Ｘ線検出器４３のＸ線検出素子４
３ａがＸ線源４２（図１参照）を臨む開口１２の内壁面
を形成する端面１３が各々断面鋸歯状に形成されている
（図３参照）。そして、それら鋸歯状端面１３のＶ字状
谷面１３ａ相互が開口１２側から見て向かい合った状態
で上下相反する側から進退する（矢印ロ，ハ参照）こと
で、そのＶ字状谷面１３ａ相互で囲まれて形成される開
口１２の幅ｗ及び高さｈ寸法が連動して縮小，拡大され
るように構成されている。As shown in FIG. 2, the pair of collimator blocks 11a and 11b are arranged in the front-rear direction on the X-ray incident side of the X-ray detector 43, and when the opposing surfaces are close to each other or rub against each other, the upper and lower reciprocal reciprocations are obtained. It is possible to advance and retreat from the side that performs (see arrows B and C). Also, the X-ray detection element 4 of the X-ray detector 43
The end faces 13 forming the inner wall surface of the opening 12 facing the X-ray source 42 (see FIG. 1) 3a are each formed in a sawtooth cross section (see FIG. 3). Then, the V-shaped valley surfaces 13a of the saw-toothed end surfaces 13 advance and retreat from opposite upper and lower sides in a state where the V-shaped valley surfaces 13a face each other as viewed from the opening 12 side (see arrows B and C), so that the V-shaped valley surfaces 13a are formed. The width w and the height h of the openings 12 formed so as to be surrounded by each other are reduced and enlarged in conjunction with each other.
【００２１】図示例では、コリメータブロック１１ａ，
１１ｂのＶ字状谷面１３ａのＶ字断面形状が、直角二等
辺三角形の直角を挟む二辺がなすＶ字状に各々形成さ
れ、コリメータブロック１１ａ，１１ｂで形成される開
口１２は、９０°回転させた正方形となっている（図２
（ａ）参照）。したがって各開口１２は、一対のコリメ
ータブロック１１ａ，１１ｂの上記進退に応じて、形状
（正方形）を保持しながら縮小，拡大される。なお、コ
リメータブロック１１ａ，１１ｂを進退させるための装
置は、公知の駆動装置（図示せず）が用いられる。In the illustrated example, the collimator blocks 11a,
The V-shaped cross-sectional shape of the V-shaped valley surface 13a of 11b is formed in a V-shape formed by two sides sandwiching a right angle of a right-angled isosceles triangle, and the opening 12 formed by the collimator blocks 11a and 11b is 90 °. It is a rotated square (Fig. 2
(A)). Therefore, each opening 12 is reduced or enlarged while maintaining the shape (square) in accordance with the advance / retreat of the pair of collimator blocks 11a and 11b. A known driving device (not shown) is used as a device for moving the collimator blocks 11a and 11b forward and backward.
【００２２】上述し、また図１に示したように、Ｘ線検
出器４３のＸ線検出素子４３ａがＸ線源４２を臨む開口
１２は、コリメータ１１を構成する一対のコリメータブ
ロック１１ａ，１１ｂを上下側から進退させることで、
任意寸法に縮小，拡大する。具体的には、図２に示すよ
うに、一対のコリメータブロック１１ａ，１１ｂを相互
に前進（矢印ロに示すように近付く方向に駆動）させれ
ば開口１２は縮小し、後退（矢印ハに示すように離れる
方向に駆動）させれば開口１２は拡大する。As described above and shown in FIG. 1, the opening 12 of the X-ray detector 43 where the X-ray detecting element 43a faces the X-ray source 42 has a pair of collimator blocks 11a and 11b constituting the collimator 11. By moving back and forth from the top and bottom,
Reduce or enlarge to any size. Specifically, as shown in FIG. 2, if the pair of collimator blocks 11a and 11b are moved forward (driven in a direction approaching as shown by arrow B), the opening 12 is reduced and retracted (shown by arrow C). The opening 12 is enlarged in such a way that the opening 12 is moved away.
【００２３】したがって、Ｘ線の透過能力を高めたい場
合は、上記開口１２の高さｈ（スライス幅５１）を拡大
してＸ線検出素子４３ａに入射するＸ線量を増やせばよ
く、これによれば、大きな（Ｘ線透過方向の寸法の大き
い）被検体４１でもノイズの少ない鮮明な断面像を得る
ことができる。被検体４１の厚み方向（スライス幅方
向）について、微細な構造，材質等の変化が予測される
場合には、コリメータ１１の開口１２の高さｈ寸法を縮
小すればよい。これによれば、被検体４１の厚み方向に
ぼけの少ない鮮明な断面像を得ることができる。Therefore, when it is desired to increase the X-ray transmission capability, the height h (slice width 51) of the opening 12 should be increased to increase the amount of X-ray incident on the X-ray detecting element 43a. For example, even with a large subject 41 (having a large dimension in the X-ray transmission direction), a clear cross-sectional image with little noise can be obtained. When a change in a minute structure, material, or the like is predicted in the thickness direction (slice width direction) of the subject 41, the height h of the opening 12 of the collimator 11 may be reduced. According to this, a clear cross-sectional image with little blur in the thickness direction of the subject 41 can be obtained.
【００２４】更に、断面像の精度を重視する場合は、コ
リメータ１１の開口幅ｗを縮小すればよく、これによれ
ば、空間分解能を高めることができ、高精度の断面像を
得ることができる。Further, when importance is attached to the accuracy of the cross-sectional image, the aperture width w of the collimator 11 may be reduced, whereby the spatial resolution can be increased and a high-accuracy cross-sectional image can be obtained. .
【００２５】また前述したように、断面像を精度よく再
構成させるためには、コリメータ１１の開口１２の寸法
を、開口幅ｗ＝開口高さｈとするのが理想的である。上
述実施形態では、開口幅ｗ又は開口高さｈの縮小，拡大
により、元の形状（正方形）を損なうことなく、開口幅
ｗ及び開口高さｈが同時に縮小，拡大されるので、高精
度の断面像を得ることができる。As described above, in order to reconstruct the cross-sectional image with high accuracy, it is ideal that the dimension of the opening 12 of the collimator 11 is set such that the opening width w is equal to the opening height h. In the above-described embodiment, the opening width w and the opening height h are simultaneously reduced and enlarged without deteriorating the original shape (square) by reducing or expanding the opening width w or the opening height h. A cross-sectional image can be obtained.
【００２６】なお上述実施形態では、本発明を第３世代
（Ｒotate/Ｒotate方式）のＸ線ＣＴ装置に適用した場
合について説明したが、これのみに限定されることはな
く、例えば第４世代（Ｓtationary/Ｒotate方式）や第
２世代（Ｔranslate/Ｒotate方式）のＸ線ＣＴ装置に本
発明を適用してもよい。In the above-described embodiment, the case where the present invention is applied to the third generation (Rotate / Rotate system) X-ray CT apparatus has been described. However, the present invention is not limited to this case. The present invention may be applied to an X-ray CT apparatus of a Stationary / Rotate type or a second generation (Translate / Rotate type).
【００２７】[0027]
【発明の効果】以上述べたように本発明では、被検体の
周囲多方向からＸ線を照射して得た多数のＸ線投影デー
タに対して画像再構成処理を施すことで被検体の断面像
を得るＸ線ＣＴ装置において、Ｘ線検出素子がＸ線源を
臨む、一対のコリメータブロックで形成される開口の幅
及び高さ寸法を、その一対のコリメータブロックの少な
くともいずれか一方の進退に応じて縮小，拡大自在にコ
リメータを設けた。As described above, according to the present invention, a large number of X-ray projection data obtained by irradiating X-rays from various directions around the subject are subjected to image reconstruction processing, thereby obtaining a cross section of the subject. In an X-ray CT apparatus for obtaining an image, the width and height of an opening formed by a pair of collimator blocks in which an X-ray detection element faces an X-ray source are adjusted to at least one of the pair of collimator blocks. A collimator is provided so that it can be reduced or enlarged accordingly.
【００２８】これによれば、Ｘ線の透過能力を高めたい
場合には上記開口の高さ寸法（スライス幅）を拡大し、
また、被検体の厚み方向（スライス幅方向）について微
細な構造，材質等の変化が予測される場合には上記開口
の高さ寸法を縮小する。更に、断面像の精度を重視する
場合は上記開口の幅を縮小するというように、重視する
性能、検査対象あるいは検査目的等に応じて上記開口寸
法を調整することができる。したがって、大きさ（Ｘ線
透過方向の寸法）やスライス幅方向の構造変化の程度の
異なる広範囲の被検体について、各々鮮明な断面像（空
間分解能が高く、ぼけやノイズも少ない断面像）を得る
ことができる。According to this, when it is desired to enhance the transmission capability of X-rays, the height dimension (slice width) of the opening is increased,
When a minute change in the structure, material, or the like in the thickness direction (slice width direction) of the subject is predicted, the height of the opening is reduced. Further, when importance is attached to the accuracy of the cross-sectional image, the size of the opening can be adjusted according to the performance to be emphasized, the inspection target, the inspection purpose, or the like, such as reducing the width of the opening. Therefore, clear cross-sectional images (cross-sectional images with high spatial resolution and little blur and noise) are obtained for a wide range of subjects having different sizes (dimensions in the X-ray transmission direction) and structural changes in the slice width direction. be able to.
【図１】本発明によるＸ線ＣＴ装置の一実施形態の要部
を示す平面図である。FIG. 1 is a plan view showing a main part of an embodiment of an X-ray CT apparatus according to the present invention.
【図２】図１中のコリメータ及びＸ線検出器部分の一部
を取り出して示す図である。FIG. 2 is a diagram illustrating a part of a collimator and an X-ray detector in FIG.
【図３】図２中からコリメータ部分を取り出し、分解し
て示す斜視図である。FIG. 3 is a perspective view showing a collimator portion taken out of FIG. 2 and exploded.
【図４】従来装置の要部を示す平面図である。FIG. 4 is a plan view showing a main part of a conventional device.
【図５】コリメータを備えた従来装置の要部を示す平面
図である。FIG. 5 is a plan view showing a main part of a conventional device provided with a collimator.
【図６】従来装置で使用されたコリメータの一例を示す
正面図である。FIG. 6 is a front view showing an example of a collimator used in a conventional device.
【図７】同じく他の例を示す正面図である。FIG. 7 is a front view showing another example.
１１ コリメータ １１ａ，１１ｂ コリメータブロック １２ 開口 ４１ 被検体 ４２ Ｘ線源 ４３ Ｘ線検出器 ４３ａ Ｘ線検出素子 ４４ Ｘ線ビーム ｗ 開口の幅 ｈ 開口の高さ DESCRIPTION OF SYMBOLS 11 Collimator 11a, 11b Collimator block 12 Aperture 41 Subject 42 X-ray source 43 X-ray detector 43a X-ray detection element 44 X-ray beam w Opening width h Opening height
フロントページの続き (72)発明者 山田 靖二 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 Ｆターム(参考） 2G001 AA01 BA11 CA01 GA13 HA07 HA08 HA13 HA14 JA01 JA04 JA06 JA20 KA03 SA01 SA02 SA04 SA30 Continued on the front page (72) Inventor Yasuji Yamada 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 2G001 AA01 BA11 CA01 GA13 HA07 HA08 HA13 HA14 JA01 JA04 JA06 JA20 KA03 SA01 SA02 SA04 SA30
Claims (2)
つつＸ線を照射することでＸ線検出器から出力される、
前記被検体の周囲多方向からの透過Ｘ線に基づく信号か
ら多数のＸ線投影データを得て画像再構成処理し、前記
被検体の断面像を得るＸ線ＣＴ装置において、 一対のコリメータブロックを前記Ｘ線検出器のＸ線入射
側に配してなり、前記Ｘ線検出器のＸ線検出素子が前記
Ｘ線源を臨む、前記一対のコリメータブロックで形成さ
れる開口の幅及び高さ寸法が、当該一対のコリメータブ
ロックの少なくともいずれか一方の進退に応じて縮小，
拡大自在のコリメータを具備することを特徴とするＸ線
ＣＴ装置。1. An X-ray source that emits X-rays while relatively rotating around a subject is output from an X-ray detector.
In an X-ray CT apparatus for obtaining a large number of X-ray projection data from signals based on transmitted X-rays from multiple directions around the subject and performing image reconstruction processing to obtain a cross-sectional image of the subject, a pair of collimator blocks includes The width and height of an opening formed by the pair of collimator blocks, which are arranged on the X-ray incident side of the X-ray detector, and the X-ray detection element of the X-ray detector faces the X-ray source. Is reduced in accordance with at least one of the pair of collimator blocks.
An X-ray CT apparatus comprising an expandable collimator.
器のＸ線入射側の前後方向に置かれ、対向面相互が近接
した又は擦り合った状態で上下側から進退自在で、前記
Ｘ線検出器のＸ線検出素子がＸ線源を臨む開口の内壁面
を形成する端面が各々断面鋸歯状に形成され、それら鋸
歯状端面の谷面相互が前記開口側から見て向かい合った
状態で上下側から進退することで、当該谷面相互で囲ま
れて形成される開口の幅及び高さ寸法が連動して縮小，
拡大されることを特徴とする請求項１に記載のＸ線ＣＴ
装置。2. A pair of collimator blocks are placed in the front-rear direction on the X-ray incident side of the X-ray detector, and can move forward and backward from upper and lower sides in a state where opposing surfaces are close to each other or rub against each other. The X-ray detection element of the detector has an end face forming the inner wall surface of the opening facing the X-ray source, and each of the end faces is formed in a sawtooth cross section, and the valley faces of the sawtooth end faces face each other when viewed from the opening side. The width and height dimensions of the opening formed by being surrounded by the valley surfaces are reduced in conjunction with
The X-ray CT according to claim 1, wherein the X-ray CT is enlarged.
apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001033581A JP2002243662A (en) | 2001-02-09 | 2001-02-09 | X-ray ct equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001033581A JP2002243662A (en) | 2001-02-09 | 2001-02-09 | X-ray ct equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002243662A true JP2002243662A (en) | 2002-08-28 |
Family
ID=18897312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001033581A Pending JP2002243662A (en) | 2001-02-09 | 2001-02-09 | X-ray ct equipment |
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| Country | Link |
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| JP (1) | JP2002243662A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100872142B1 (en) | 2007-01-30 | 2008-12-08 | 서울시립대학교 산학협력단 | Variable Collimator |
| KR200449959Y1 (en) | 2008-12-05 | 2010-08-25 | (주)바텍이우홀딩스 | Collimator of dental x-ray imaging apparatus |
| JP2013044717A (en) * | 2011-08-26 | 2013-03-04 | Ntn Corp | Inspection method of rolling element, manufacturing method of rolling element and rolling element |
| CN108802074A (en) * | 2018-08-02 | 2018-11-13 | 赵克 | The detection method of zirconium oxide bilayer All-ceramic restoration body piercing porcelain internal flaw |
-
2001
- 2001-02-09 JP JP2001033581A patent/JP2002243662A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100872142B1 (en) | 2007-01-30 | 2008-12-08 | 서울시립대학교 산학협력단 | Variable Collimator |
| KR200449959Y1 (en) | 2008-12-05 | 2010-08-25 | (주)바텍이우홀딩스 | Collimator of dental x-ray imaging apparatus |
| JP2013044717A (en) * | 2011-08-26 | 2013-03-04 | Ntn Corp | Inspection method of rolling element, manufacturing method of rolling element and rolling element |
| US10048214B2 (en) | 2011-08-26 | 2018-08-14 | Ntn Corporation | Rolling element inspection method, rolling element manufacturing method, and rolling element |
| CN108802074A (en) * | 2018-08-02 | 2018-11-13 | 赵克 | The detection method of zirconium oxide bilayer All-ceramic restoration body piercing porcelain internal flaw |
| CN108802074B (en) * | 2018-08-02 | 2020-11-06 | 赵克 | Method for detecting internal defects of zirconia double-layer all-ceramic restoration body decorative ceramic |
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