JPH06154207A - Radiographic apparatus and positioning method thereof - Google Patents
Radiographic apparatus and positioning method thereofInfo
- Publication number
- JPH06154207A JPH06154207A JP4308809A JP30880992A JPH06154207A JP H06154207 A JPH06154207 A JP H06154207A JP 4308809 A JP4308809 A JP 4308809A JP 30880992 A JP30880992 A JP 30880992A JP H06154207 A JPH06154207 A JP H06154207A
- Authority
- JP
- Japan
- Prior art keywords
- ray
- grid
- ray tube
- focusing
- detector
- 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
- 238000000034 method Methods 0.000 title claims description 10
- 230000005855 radiation Effects 0.000 claims abstract description 12
- 238000003384 imaging method Methods 0.000 claims description 25
- 239000011888 foil Substances 0.000 abstract description 18
- 238000006073 displacement reaction Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000010365 information processing Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 3
- 210000001015 abdomen Anatomy 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000002601 radiography Methods 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
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- Radiography Using Non-Light Waves (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、放射線を用いて被検者
のＸ線撮影を行なうＸ線撮影装置、特にグリッドとＸ線
自動露出装置の組み込まれたＸ線撮影装置に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus for performing X-ray imaging of a subject using radiation, and more particularly to an X-ray imaging apparatus incorporating a grid and an X-ray automatic exposure device.
【０００２】[0002]
【従来の技術】従来から行われている胸部、腹部などの
Ｘ線撮影システム例の概略を図３に示す。この図におい
て、１はＸ線管、２はコリメータ、３は被写体、４はグ
リッド、５は増感紙、６は増感紙に密着されたフィル
ム、７はＸ線検出器、８はＸ線自動露出制御装置で、そ
の構成は、９の電流電圧変換回路、１０の積分回路、１
１の比較回路、１２の濃度を設定するための基準電圧設
定器ないし発生器、１３のＸ線遮断信号発生回路からな
り、１４はＸ線制御回路、１５は高電圧発生器である。2. Description of the Related Art FIG. 3 shows an outline of an example of a conventional X-ray imaging system for the chest and abdomen. In this figure, 1 is an X-ray tube, 2 is a collimator, 3 is a subject, 4 is a grid, 5 is an intensifying screen, 6 is a film closely attached to the intensifying screen, 7 is an X-ray detector, and 8 is an X-ray. The automatic exposure control device is composed of a current-voltage conversion circuit 9 and an integration circuit 10
1 is a comparison circuit, 12 is a reference voltage setter or generator for setting the concentration, 13 is an X-ray cutoff signal generation circuit, 14 is an X-ray control circuit, and 15 is a high voltage generator.
【０００３】Ｘ線検出器７として図４に示すように、１
つもしくは複数の検出器（蛍光体方式、半導体方式、イ
オンチャンバ方式等）が採光野７ａ、７ｂ、７ｃに配置
されている。Ｘ線自動露出装置は、図３に示すような装
置の構成により、Ｘ線管１から被写体３を透過したＸ線
をＸ線検出器７で受け、電流電圧変換回路９で電気信号
に変換し、この電気信号を積分回路１０で積分し、その
積分値があらかじめ基準電圧設定器１２により設定され
た基準電圧に達したとき比較回路１１によりＸ線遮断信
号を発生し、Ｘ線の曝射を遮断させ最適なフィルム濃度
を得るものである。As an X-ray detector 7, as shown in FIG.
One or a plurality of detectors (fluorescent material type, semiconductor type, ion chamber type, etc.) are arranged in the light collecting fields 7a, 7b, 7c. The X-ray automatic exposure device has the configuration of the device as shown in FIG. 3 and receives the X-rays transmitted from the X-ray tube 1 through the subject 3 by the X-ray detector 7 and converts them into electric signals by the current-voltage conversion circuit 9. The electric signal is integrated by the integrating circuit 10, and when the integrated value reaches the reference voltage set in advance by the reference voltage setting unit 12, the comparison circuit 11 generates an X-ray cutoff signal to irradiate the X-ray. The film is blocked to obtain the optimum film density.
【０００４】また、Ｘ線が被写体を透過するとき、発生
する散乱Ｘ線（二次Ｘ線）が画像に与える影響は大き
い。この散乱Ｘ線を効率よく除去するために散乱Ｘ線除
去用グリッド４が使用され、Ｘ線コントラストと鮮鋭度
を向上させた診断性の高いＸ線画像を得るのに役立って
いる。使用されるグリッドには、直線グリッドと、クロ
スグリッドの２つの基本型があり、それぞれ平行グリッ
ドと集束グリッドに分けられる。Further, when X-rays pass through a subject, scattered X-rays (secondary X-rays) generated have a great influence on an image. The scattered X-ray removal grid 4 is used to efficiently remove the scattered X-rays, which is useful for obtaining an X-ray image with improved diagnostic properties and improved X-ray contrast and sharpness. There are two basic types of grids used, straight grids and cross grids, which are divided into parallel grids and focusing grids, respectively.
【０００５】図５は平行グリッドの断面図であり、鉛箔
４０は、中間物質４１と交互に平行に配置されている。
図６は集束グリッドの断面図であり、鉛箔４０と、中間
物質４１は集束点４２に向いて配置されている。FIG. 5 is a cross-sectional view of a parallel grid, in which lead foils 40 are arranged alternately in parallel with intermediate material 41.
FIG. 6 is a cross-sectional view of the focusing grid, in which the lead foil 40 and the intermediate substance 41 are arranged facing the focusing point 42.
【０００６】[0006]
【発明が解決しようとする課題】グリッドを使用したＸ
線撮影では、グリッド・カットオフの影響により、撮影
されたＸ線写真に明暗のむらが生じたり、全体的に明る
くなることがある。グリッド・カットオフとは、一次Ｘ
線とグリッドの鉛箔の位置関係が適正でないために生じ
る一次Ｘ線損失のことである。図７は平行グリッドによ
りグリッド・カットオフが生じた場合を示すもので、４
３はＸ線管焦点、４４はフィルム、４５はＸ線がグリッ
ドの鉛箔４０を透過した際の影をそれぞれ示す。鉛箔４
０ａは一次Ｘ線の方向に配列された鉛箔４０ｂの像４５
ｂよりも広い像４５ａとして投影され、そのぶんだけ一
次Ｘ線はフィルム４４に到達しない。その結果、Ｘ線写
真では、カットオフの起きている部分はカットオフの起
きていないところに比べ明るくなる。カットオフの量
は、一般にグリッド比（鉛箔４０の高さと間隔の比）が
高く、グリッド４とＸ線管焦点４３の距離が短いほど多
くなる。X using a grid
In the radiography, due to the influence of the grid cutoff, the radiograph taken may have uneven brightness or may become bright as a whole. Grid cutoff is the primary X
It is the primary X-ray loss that occurs because the positional relationship between the lines and the lead foil of the grid is not correct. Figure 7 shows the case where the grid cutoff occurs due to the parallel grid.
3 is an X-ray tube focus, 44 is a film, and 45 is a shadow when X-rays pass through the lead foil 40 of the grid. Lead foil 4
0a is an image 45 of the lead foil 40b arranged in the direction of the primary X-ray.
The image is projected as an image 45a wider than b, and the primary X-ray does not reach the film 44 by that much. As a result, in the X-ray photograph, the part where the cutoff occurs is brighter than the part where the cutoff does not occur. The amount of cutoff is generally high as the grid ratio (the ratio of the height of the lead foil 40 to the interval) is large, and the cutoff amount increases as the distance between the grid 4 and the X-ray tube focus 43 decreases.
【０００７】つぎに、一次Ｘ線とグリッド４の鉛箔４０
の位置関係が適正でないために生じるグリッド・カット
オフの例について述べる。Next, the primary X-ray and the lead foil 40 of the grid 4
An example of the grid cutoff that occurs due to the improper positional relationship between the positions will be described.
【０００８】図８は、裏と表が逆さまになった集束グリ
ッド４の鉛箔４０にＸ線が放射される例を示している。
この例では、グリッドの集束点４２とされるところにＸ
線管の焦点４３（放射源）があるが、この場合Ｘ線写真
の中央部は暗く、周辺部はカットオフがひどいので明る
くなる。FIG. 8 shows an example in which X-rays are radiated to the lead foil 40 of the focusing grid 4 whose front and back are upside down.
In this example, X is placed at the focus point 42 of the grid.
There is a focal point 43 (radiation source) of the X-ray tube, but in this case, the central portion of the X-ray photograph is dark and the peripheral portion is bright due to the severe cutoff.
【０００９】図９は、Ｘ線管焦点４３は正確に集束距離
に設置されているが、グリッド４の集束点４２から横に
ずれている横方向偏位の例である。この場合、すべての
鉛箔４０は均等に一次Ｘ線をカットオフするので、フィ
ルム４４の全面にわたり均等に明るいＸ線写真となる。
横方向偏位による一次Ｘ線損失量の計算式はつぎの通り
である。FIG. 9 shows an example of lateral displacement in which the X-ray tube focal point 43 is accurately placed at the focusing distance, but is laterally displaced from the focusing point 42 of the grid 4. In this case, all the lead foils 40 cut off the primary X-rays evenly, so that the entire surface of the film 44 becomes an evenly bright X-ray photograph.
The formula for calculating the amount of primary X-ray loss due to lateral displacement is as follows.
【００１０】Ｌ＝（ｒｂ／ｆ0）×１００％、Ｌは一次
Ｘ線損失量、ｒはグリッド比、ｂは横方向偏位距離（ｃ
ｍ）、ｆ0はグリッド４の集束距離（ｃｍ）である。た
とえば、集束距離が１８０ｃｍのグリッドでは、グリッ
ド比が５：１のときには６ｃｍの横方向偏位で一次Ｘ線
損失は１７％であるが、１６：１では一次Ｘ線損失は５
３％にもなる。L = (rb / f 0 ) × 100%, L is the amount of primary X-ray loss, r is the grid ratio, b is the lateral displacement distance (c
m) and f 0 are focusing distances (cm) of the grid 4. For example, in a grid with a focusing distance of 180 cm, a lateral deviation of 6 cm gives a primary X-ray loss of 17% at a grid ratio of 5: 1, while at 16: 1 the primary X-ray loss is 5%.
It can be as high as 3%.
【００１１】図１０は、グリッド４が傾斜した場合の例
である。グリッドの集束距離が比較的長い場合、グリッ
ド４の集束点４２とＸ線管焦点４３との横方向偏位に対
して、Ｘ線管焦点４３とグリッド４間距離偏位は小さい
ので前記横方向の偏位と同等と考えられるため、一次Ｘ
線は均等に失われる。FIG. 10 shows an example in which the grid 4 is tilted. When the focusing distance of the grid is relatively long, the lateral deviation between the focal point 42 of the grid 4 and the X-ray tube focal point 43 is smaller than the lateral deviation between the X-ray tube focal point 43 and the grid 4. Since it is considered to be equivalent to the deviation of
The lines are evenly lost.
【００１２】図１１は、Ｘ線管焦点４３は正確にグリッ
ド４の中心線上にあるが、Ｘ線管焦点４３がグリッド４
の集束点４２の遠くか近くかに位置している、Ｘ線管焦
点−グリッド間距離偏位の例である。In FIG. 11, the X-ray tube focus 43 is exactly on the center line of the grid 4, but the X-ray tube focus 43 is the grid 4
3 is an example of an X-ray tube focal point-grid distance deviation located far or near the focusing point 42 of FIG.
【００１３】カットオフは、フィルムの中心から離れる
につれて、徐々に大きくなり、Ｘ線写真では、中心部は
影響を受けないが、周辺部は明るくなる。The cut-off gradually increases as the distance from the center of the film increases, and in the X-ray photograph, the central portion is not affected but the peripheral portion becomes bright.
【００１４】図１２、図１３は、横方向偏位とＸ線管焦
点−グリッド間距離偏位の両方の偏位が生じた場合の例
である。この場合には、カットオフが均等ではないの
で、Ｘ線写真の一方では明るく、反対側では暗くなる。FIGS. 12 and 13 show examples in which both lateral displacement and X-ray tube focal point-grid distance displacement occur. In this case, since the cutoffs are not uniform, one side of the X-ray photograph is bright and the other side is dark.
【００１５】以上は、理想的なグリッドを使用したとき
の現象であるが、実際には、グリッドの製造における精
度には限界がある。すなわち、鉛箔４０と、中間物質４
１の並びの間隔を均一にしたり、グリッド４の集束点４
２への向きにこれらを精度よく合わせたりする事は非常
にむずかしい。とくに、近年多用されている高グリッド
比のグリッドでは、前記したような一次Ｘ線とグリッド
の鉛箔の位置関係が適正でないために生じるグリッド・
カットオフや、製造上の精度のばらつきに起因するカッ
トオフの影響が特に出やすくなっている。The above is the phenomenon when an ideal grid is used, but in reality, there is a limit to the accuracy in manufacturing the grid. That is, the lead foil 40 and the intermediate substance 4
The intervals of 1 are made uniform, or the focusing points 4 of the grid 4 are
It is very difficult to accurately match these to the direction of 2. In particular, in the case of a grid with a high grid ratio that has been widely used in recent years, the grid caused by the improper positional relationship between the primary X-ray and the lead foil of the grid as described above.
The influence of the cutoff and the cutoff due to the variation in manufacturing precision is particularly likely to occur.
【００１６】また、グリッド４をＸ線撮影装置に取り付
ける場合に、グリッド４に歪みが生じる場合がある。こ
の場合には、グリッド４の集束点４２が位置ずれを起こ
し、正規の位置にＸ線焦点４３があったとしても、横方
向偏位とＸ線管焦点−グリッド間距離偏位の両方の偏位
が生じた状態となり、図１２、図１３で示したようなＸ
線写真の一方では明るく、反対側では暗くなる現象が起
こる。When the grid 4 is attached to the X-ray imaging apparatus, the grid 4 may be distorted. In this case, even if the focal point 42 of the grid 4 is displaced and the X-ray focal point 43 is located at the normal position, both the lateral deviation and the X-ray tube focal point-grid distance deviation are deviated. Position is generated and X as shown in FIG. 12 and FIG.
The phenomenon occurs that one side of the line photograph is bright and the other side is dark.
【００１７】一般的なＸ線撮影室内には、一つの放射線
源に対して、撮影部位に応じて２つ以上の撮影装置（例
えば、立位で撮影する場合、ベッドの下に撮影装置を入
れて臥位で撮影する場合等）を配置する場合が多く、撮
影目的に応じて放射線源を撮影装置と相対向させ、中心
合わせをする必要がある。また、検診車にＸ線撮影シス
テムを搭載する場合には、スペースの関係で放射線源ま
たは撮影装置を移動もしくは回転させることがあり、撮
影の度に放射線源と撮影装置の中心合わせを行なう必要
がある。この位置合わせを行なうのに、グリッドによる
カットオフを最小にするように試し撮りをするので時間
がかかるため、一次Ｘ線とグリッドの鉛箔の位置関係を
最適、かつ簡単に合わせられる装置や方法が望まれてい
る。In a general X-ray radiography room, two or more radiographing devices are installed for one radiation source according to the radiographing region (for example, when radiographing in a standing position, the radiographing devices are placed under a bed. It is often the case that the radiation source is opposed to the image capturing device and the center is aligned depending on the purpose of image capturing. Further, when an X-ray imaging system is mounted on a medical examination vehicle, the radiation source or the imaging device may be moved or rotated due to space constraints, and it is necessary to center the radiation source and the imaging device for each imaging. is there. It takes time to perform this alignment because a trial shot is taken so as to minimize the cutoff by the grid. Therefore, the device and method for optimally and easily aligning the positional relationship between the primary X-ray and the lead foil of the grid. Is desired.
【００１８】本発明は、このような事情に鑑みなされた
もので、その目的は、Ｘ線放射源とグリッドの鉛箔の位
置関係を最適に、かつ簡単に合わせることのできるＸ線
撮影装置及びその位置合わせ方法を提供することにあ
る。The present invention has been made in view of the above circumstances, and an object thereof is to provide an X-ray imaging apparatus capable of optimally and easily adjusting the positional relationship between the X-ray radiation source and the lead foil of the grid. It is to provide the alignment method.
【００１９】[0019]
【課題を解決するための手段】本発明は、上記目的を達
成するために、Ｘ線撮影装置において、Ｘ線自動露出装
置のＸ線検出器を用いてグリッドを透過するＸ線強度を
測定し、その測定値をもとにグリッドとＸ線放射源の位
置合わせを行うことを特徴としている。In order to achieve the above object, the present invention measures the intensity of X-rays transmitted through a grid in an X-ray imaging apparatus using an X-ray detector of an automatic X-ray exposure apparatus. The feature is that the grid and the X-ray radiation source are aligned based on the measured values.
【００２０】[0020]
【実施例】以下、本発明におけるＸ線管焦点とグリッド
の自動位置合わせ機能を有するＸ線撮影装置の一実施例
について図を参照しながら説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an X-ray imaging apparatus having an X-ray tube focus and grid automatic alignment function according to the present invention will be described below with reference to the drawings.
【００２１】図１は、図３に示すような従来から行われ
ているＸ線自動露出制御装置付きＸ線撮影装置例に、本
発明の一実施例を付加したＸ線撮影装置を示す図であ
り、１はＸ線管、２はコリメータ、４はグリッド、７
ａ，７ｂはＸ線検出器、８はＸ線自動露出制御装置で、
その構成は、９の電流電圧変換回路、１６の加算器、１
０の積分回路、１１の比較回路、１２の濃度を設定する
ための基準電圧設定器ないし発生器、１３のＸ線遮断信
号発生回路からなり、１４はＸ線制御回路、１５は高電
圧発生器である。FIG. 1 is a diagram showing an X-ray imaging apparatus in which an embodiment of the present invention is added to the conventional X-ray imaging apparatus with an automatic X-ray exposure control apparatus as shown in FIG. Yes, 1 is an X-ray tube, 2 is a collimator, 4 is a grid, 7
a and 7b are X-ray detectors, 8 is an X-ray automatic exposure control device,
Its configuration is 9 current-voltage conversion circuits, 16 adders, 1
It comprises an integrating circuit of 0, a comparing circuit of 11, a reference voltage setting device or generator for setting the concentration of 12, an X-ray cutoff signal generating circuit of 13, an X-ray control circuit, and a high voltage generator 15 Is.
【００２２】Ｘ線自動露出制御撮影では、Ｘ線管から被
写体を透過したＸ線をＸ線検出器７ａ，７ｂで受け、電
流電圧変換回路９で電気信号に変換し、加算器１６を介
しこの電気信号を積分回路１０で積分し、その積分値が
あらかじめ設定された基準電圧に達したとき比較回路１
１によりＸ線遮断信号を発生し、Ｘ線の曝射を遮断させ
最適なフィルム濃度を得るものである。In the automatic X-ray exposure control photography, the X-rays transmitted through the subject from the X-ray tube are received by the X-ray detectors 7a and 7b, converted into electric signals by the current-voltage conversion circuit 9, and then added through the adder 16. The electric signal is integrated by the integration circuit 10, and when the integrated value reaches a preset reference voltage, the comparison circuit 1
1 generates an X-ray blocking signal to block X-ray exposure and obtain an optimum film density.
【００２３】次に示すものが、本発明により付加された
Ｘ線管焦点とグリッドの自動位置合わせを行うための装
置の構成であり、１７はアナログ信号をデジタル信号に
変換するためのＡ／Ｄ変換器、１８は情報処理装置、１
９はＸ線管球を動かすパルスモータのドライバ、２０ａ
はＸ線管球を図中Ｘ方向に動かすパルスモータ、２０ｂ
はＸ線管球をＹ方向に動かすパルスモータである。The following is the configuration of the apparatus for automatically aligning the X-ray tube focus and grid added by the present invention, and 17 is an A / D for converting an analog signal into a digital signal. A converter, 18 is an information processing device, 1
9 is a pulse motor driver for moving the X-ray tube, 20a
Is a pulse motor for moving the X-ray tube in the X direction in the figure, 20b
Is a pulse motor that moves the X-ray tube in the Y direction.
【００２４】情報処理装置１８は、Ｘ線管１をＸ軸方
向、Ｙ軸方向に動かすステージ２０のパルスモータ２０
ａ，２０ｂを制御し、ＸＹステージ内の希望の位置にＸ
線管１を移動するとともにステージ内でのＸ線管１の座
標も管理する。また、情報処理装置１８はＸ線検出器７
ａ，７ｂでのＸ線強度が電気信号に変換されたものをＡ
／Ｄ変換器１７を通して検出する。The information processing apparatus 18 includes a pulse motor 20 of a stage 20 that moves the X-ray tube 1 in the X-axis direction and the Y-axis direction.
a, 20b to control the X position at the desired position in the XY stage.
While moving the X-ray tube 1, it also manages the coordinates of the X-ray tube 1 in the stage. In addition, the information processing device 18 uses the X-ray detector 7
A converted from the X-ray intensity at a and 7b into an electric signal
It is detected through the / D converter 17.
【００２５】図１で、Ｙ軸を固定し、Ｘ線管１からＸ線
を出しながらＸ軸方向にＸ線管１を移動しつつ、同時に
グリッド４を透過してくるＸ線の強度をＸ線検出器７
ａ，７ｂを介して測定する。つぎに、ある距離だけＹ軸
方向にＸ線管１を移動した後、同様にＹ軸を固定し、Ｘ
線管１からＸ線を出しながらＸ軸方向にＸ線管１を移動
しつつ、同時にグリッド４を透過してくるＸ線の強度を
Ｘ線検出器７ａ，７ｂを介して測定する。In FIG. 1, the Y-axis is fixed, the X-ray tube 1 is moved in the X-axis direction while emitting X-rays from the X-ray tube 1, and at the same time, the intensity of X-rays transmitted through the grid 4 is X. Line detector 7
a, 7b. Next, after moving the X-ray tube 1 in the Y-axis direction by a certain distance, the Y-axis is similarly fixed and
The X-ray tube 1 is moved in the X-axis direction while emitting X-rays from the X-ray tube 1, and at the same time, the intensity of X-rays transmitted through the grid 4 is measured via the X-ray detectors 7a and 7b.
【００２６】図２は、現在一般的に使用されている集束
点４２を持ったグリッド４と図４の例で示される位置に
ある７ａ，７ｂを使用し、前記の測定方法により得られ
た集束グリッド４を透過するＸ線強度とＸＹ座標の位置
関係を表している。２１はＸ線検出器７ａで検出したＸ
線強度のピーク部の波形、２２はＸ線検出器７ｂで検出
したＸ線強度のピーク部の波形を示している。FIG. 2 shows a focus obtained by the above-mentioned measuring method using a grid 4 having a focusing point 42 which is generally used at present and 7a and 7b at the positions shown in the example of FIG. The positional relationship between the X-ray intensity transmitted through the grid 4 and the XY coordinates is shown. 21 is X detected by the X-ray detector 7a
The waveform of the peak portion of the line intensity, 22 shows the waveform of the peak portion of the X-ray intensity detected by the X-ray detector 7b.
【００２７】Ｘ線検出器７ａ，７ｂがある程度の面積を
持っているため、この測定では、検出器のＸ線検出出力
に鋭いピーク波形は現れないが、Ｘ線検出器７ａ，７ｂ
の中心部と集束グリッド４の実際の集束点４２を結ぶ直
線上にＸ線管焦点４３が来たときにグリッド４を透過し
てＸ線検出器７ａ，７ｂのＸ線検出出力は最大となる。
ここで、Ｘ線強度の最大点をＸ線強度ピーク部の半値幅
の中心の座標とすれば、２回の測定で各Ｘ線検出器７
ａ，７ｂの各Ｘ線強度の最大点が２点ずつ得られる。Since the X-ray detectors 7a and 7b have a certain area, a sharp peak waveform does not appear in the X-ray detection output of the detector in this measurement, but the X-ray detectors 7a and 7b.
When the X-ray tube focal point 43 comes on a straight line connecting the central part of the X-rays and the actual focusing point 42 of the focusing grid 4, the X-ray detection output of the X-ray detectors 7a and 7b becomes maximum through the grid 4. .
Here, assuming that the maximum point of the X-ray intensity is the coordinates of the center of the half-value width of the X-ray intensity peak portion, each X-ray detector 7 is measured twice.
Two maximum points of each X-ray intensity of a and 7b are obtained.
【００２８】図２に示すように、Ｘ線検出器７ａで得ら
れたピーク点をそれぞれ、Ｐa1（ｘa1，ｙa1）、Ｐ
a2（ｘa2，ｙa2）、Ｘ線検出器７ｂで得られたピーク点
をＰb1（ｘb1，ｙb1）、Ｐb2（ｘb2，ｙb2）とすれば、
集束グリッド４の集束点４２は、Ｐa1Ｐa2を結んだ直線
とＰb1Ｐb2を結んだ直線の交点の座標Ｐ（ｘ，ｙ）であ
る。この座標のｘ，ｙを計算すると以下のようになる。As shown in FIG. 2, the peak points obtained by the X-ray detector 7a are represented by P a1 (x a1 , y a1 ) and P a1 , respectively.
If a2 (x a2 , y a2 ) and the peak points obtained by the X-ray detector 7b are P b1 (x b1 , y b1 ), P b2 (x b2 , y b2 ),
The focusing point 42 of the focusing grid 4 is the coordinate P (x, y) of the intersection of the straight line connecting P a1 P a2 and the straight line connecting P b1 P b2 . The calculation of x and y of these coordinates is as follows.
【００２９】[0029]
【外１】 [Outer 1]
【００３０】ここで、集束グリッド４の集束点４２とＸ
線管球の焦点４３を合わせるためには、管球を上記で求
めた座標Ｐ（ｘ，ｙ）に移動すればよい。この原理は、
Ｘ線管のステージのＸ軸に対してグリッドが平行でない
場合でも同様に位置合わせができる。また、Ｘ線管球の
ステージに対するＸ線撮影装置の位置、すなわちグリッ
ドやＸ線検出器の位置が不明な場合でも位置合わせが可
能である。Here, the focusing point 42 of the focusing grid 4 and X
In order to adjust the focus 43 of the linear tube, the tube may be moved to the coordinate P (x, y) obtained above. This principle is
Even when the grid is not parallel to the X axis of the stage of the X-ray tube, the alignment can be performed similarly. Further, even if the position of the X-ray imaging apparatus with respect to the stage of the X-ray tube, that is, the positions of the grid and the X-ray detector are unknown, the alignment can be performed.
【００３１】ここで、Ｘ線検出器のピークを鋭くするた
めには、Ｘ線検出器７ａ，７ｂのＸ軸方向の幅を狭くし
たり、Ｘ線を遮る鉛板のようなもので検出器７ａ，７ｂ
をマスクすればよい。Here, in order to sharpen the peak of the X-ray detector, the width of the X-ray detectors 7a and 7b in the X-axis direction is narrowed, or a detector such as a lead plate that shields the X-rays is used. 7a, 7b
Should be masked.
【００３２】（第２の実施例）先に説明した第１の実施
例において、Ｘ線管１のステージ２０に対するＸ線検出
器７ａ，７ｂの位置が明確な場合にはＸ線検出器７ａ，
７ｂの中心の座標がわかるので、図１でＹ軸を固定しＸ
線管１からＸ線を出しながらＸ軸方向にＸ線管１を移動
しつつ、同時にグリッド４を透過してくるＸ線の強度の
測定は１回だけでよく、第１の実施例と同等の位置合わ
せが可能となる。この場合、測定時間は、第１の実施例
に対し半分になる。(Second Embodiment) In the first embodiment described above, when the positions of the X-ray detectors 7a, 7b with respect to the stage 20 of the X-ray tube 1 are clear, the X-ray detectors 7a, 7b
Since you can see the coordinates of the center of 7b, fix the Y axis in
The X-ray tube 1 is moved in the X-axis direction while emitting X-rays from the X-ray tube 1, and at the same time, the intensity of the X-rays transmitted through the grid 4 only needs to be measured once, which is equivalent to the first embodiment. Can be aligned. In this case, the measurement time is half that of the first embodiment.
【００３３】（第３の実施例）第１、第２の実施例では
Ｘ線検出器は２カ所であったが、３カ所以上のＸ線検出
器を用いて、検出器の組み合わせを変えグリッド４の集
束点を計算し位置合わせを行ってもよい。測定結果から
集束点Ｐが複数求められた場合には、それらの座標位置
の平均をとるなどすれば、さまざまなグリッド４に対し
より最適な位置合わせが可能となる。複数の検出器のＸ
線強度出力の取り込みを同時に行えば、管球１を動かし
ながらの測定は、前記実施例で説明したように１回また
は２回でよい。(Third Embodiment) In the first and second embodiments, there are two X-ray detectors, but by using X-ray detectors at three or more places, the combination of detectors can be changed to form a grid. The focusing points of 4 may be calculated and the alignment may be performed. When a plurality of focus points P are obtained from the measurement result, the coordinates of the coordinate points are averaged to enable more optimal alignment with respect to various grids 4. X for multiple detectors
If the line intensity output is taken in at the same time, the measurement while moving the tube 1 may be performed once or twice as described in the above embodiment.
【００３４】（第４の実施例）第１、第２、第３の実施
例では、複数のＸ線検出器を使用しているが、Ｘ線検出
器が１つしかない場合には、採光野が複数あったとして
も検出器の出力は一つなので、Ｘ線の強度測定時にピー
クが検出されてもそのピークがどの採光野でのピークな
のか判定できない。この場合には、グリッドの前面また
は、Ｘ線検出器とグリッドの間にマスクを入れ、ひとつ
の採光野ごとに測定すればよい。これにより、前記実施
例と同等の座標を得ることができるため位置合わせが可
能となる。(Fourth Embodiment) In the first, second and third embodiments, a plurality of X-ray detectors are used. However, when there is only one X-ray detector, the light is collected. Since there is only one detector output even if there are multiple fields, even if a peak is detected during X-ray intensity measurement, it is not possible to determine in which lighting field the peak is. In this case, a mask may be placed on the front surface of the grid or between the X-ray detector and the grid, and measurement may be performed for each lighting field. As a result, it is possible to obtain the same coordinates as those in the above-described embodiment, so that it is possible to perform the alignment.
【００３５】（第５実施例）前記実施例では、Ｘ線管球
を平行移動する方法をとっているが、Ｘ線撮影装置を平
行移動しても前記実施例と同様に位置合わせが可能であ
る。(Fifth Embodiment) In the above-described embodiment, the method of moving the X-ray tube in parallel is adopted. However, even if the X-ray imaging apparatus is moved in parallel, the alignment can be performed in the same manner as in the above-mentioned embodiment. is there.
【００３６】（第６実施例）Ｘ線撮影装置側を動かす場
合に、Ｘ線管球１と、Ｘ線検出器７の相対位置がわかっ
ていてＸ線撮影装置の回転角度を検出する方法があれ
ば、Ｘ線撮影装置の平行移動だけでなく回転する方法を
とっても位置合わせが可能である。(Sixth Embodiment) A method of detecting the rotation angle of the X-ray imaging apparatus when the X-ray imaging apparatus side is moved and the relative position of the X-ray tube 1 and the X-ray detector 7 is known. If so, the alignment can be performed not only by the parallel movement of the X-ray imaging apparatus but also by the rotation method.
【００３７】[0037]
【発明の効果】以上詳述したように、本発明によれば、
グリッド・カットオフによる影響の少ないＸ線写真を撮
るための位置の調整が、撮影、現像を繰り返す従来の位
置合わせ方法にくらべ、簡単に短時間でできるようにな
る。As described in detail above, according to the present invention,
The position adjustment for taking an X-ray photograph, which is less affected by the grid cutoff, can be easily performed in a shorter time than the conventional alignment method in which photographing and development are repeated.
【００３８】さらに、実測値をもとに位置合わせを行う
ため、グリッドの設計値として指定された集束点にＸ線
管の焦点を合わせる場合に比べ、よりグリッド・カット
オフによる影響の少ないＸ線写真を撮るための位置の調
整ができるようになる。Further, since the alignment is performed based on the measured values, the X-rays are less affected by the grid cutoff than when the X-ray tube is focused on the focal point designated as the design value of the grid. You will be able to adjust the position for taking pictures.
【００３９】３カ所以上の検出器を用いれば、たとえ歪
んだグリッドを使用している場合でも、グリッド・カッ
トオフによる明暗差が最小になる位置にＸ線管焦点を合
わせることも可能となる。If three or more detectors are used, it is possible to focus the X-ray tube at a position where the difference in brightness due to the grid cutoff is minimized even if a distorted grid is used.
【図１】本発明による一実施例であるＸ線撮影装置を示
す説明図FIG. 1 is an explanatory view showing an X-ray imaging apparatus which is an embodiment according to the present invention.
【図２】集束点を持ったグリッドと２つのＸ線検出器を
使用し、第１の実施例の測定方法により得られた集束グ
リッドを透過するＸ線強度とＸＹ座標の位置関係と、Ｘ
線検出器で検出したＸ線強度のピーク部の波形を示した
図FIG. 2 shows a positional relationship between X-ray intensities and XY coordinates transmitted through the focusing grid obtained by the measuring method of the first embodiment using a grid having a focusing point and two X-ray detectors, and X.
The figure which showed the waveform of the peak part of the X-ray intensity detected by the X-ray detector.
【図３】被検者の胸部・腹部などのＸ線撮影を行うた
め、従来から行われているＸ線撮影システム例の概略を
示す図、FIG. 3 is a diagram showing an outline of an example of a conventional X-ray imaging system for performing X-ray imaging of the chest and abdomen of a subject,
【図４】胸部撮影において複数の採光野を使用する場合
の一例を示す図、FIG. 4 is a diagram showing an example of using a plurality of light-collecting fields in chest imaging,
【図５】平行グリッドの断面図、FIG. 5 is a sectional view of a parallel grid,
【図６】集束グリッドの断面図、FIG. 6 is a sectional view of a focusing grid,
【図７】グリッド・カットオフが生じた場合を示す図、FIG. 7 is a diagram showing a case where a grid cutoff occurs,
【図８】裏と表が逆さまになった集束グリッドの鉛箔に
Ｘ線が放射される例を示す図、FIG. 8 is a diagram showing an example in which X-rays are radiated on a lead foil of a focusing grid in which the back and front are upside down,
【図９】Ｘ線管焦点は正確に集束距離に設置されている
が、グリッドの集束点から横にずれている横方向偏位の
例を示す図、FIG. 9 is a diagram showing an example of lateral displacement in which the X-ray tube focal point is set at a precise focusing distance, but is laterally displaced from the focal point of the grid;
【図１０】グリッドが傾斜した場合を示す図、FIG. 10 is a diagram showing a case where the grid is tilted,
【図１１】Ｘ線管焦点は正確にグリッドの中心線上にあ
るが、Ｘ線管焦点がグリッドの集束点の遠くか近くかに
位置している、Ｘ線管焦点−グリッド間距離偏位の例を
示す図、FIG. 11: X-ray tube focus-grid distance deviation where the X-ray tube focus is exactly on the centerline of the grid, but the X-ray tube focus is located far or near the focal point of the grid. Figure showing an example,
【図１２】横方向偏位とＸ線管焦点−グリッド間距離偏
位の両方の偏位が生じた場合の例を示す図、FIG. 12 is a diagram showing an example in which both lateral displacement and X-ray tube focus-grid distance displacement occur.
【図１３】横方向偏位とＸ線管焦点−グリッド間距離偏
位の両方の偏位が生じた場合の例を示す図である。FIG. 13 is a diagram showing an example in which both lateral displacement and X-ray tube focus-grid distance displacement occur.
１Ｘ線管 ２ コリメータ ３ 被写体 ４ グリッド ５ 増感紙 ６ 増感紙に密着されたフィルム ７Ｘ線検出器 ８Ｘ線自動露出装置 ９ 電流電圧変換回路 １０ 積分回路 １１ 比較回路 １２ 基準電圧設定器 １３ Ｘ線遮断信号発生回路 １４ Ｘ線制御回路 １５ 高電圧発生器 １６ 加算器 １７ Ａ／Ｄ変換器 １８ 情報処理装置 １９ モータドライバ ２０ａ Ｘ軸駆動モータ ２０ｂ Ｙ軸駆動モータ ２１ Ｘ線検出器７ａで検出したＸ線強度のピーク部の
波形 ２２ Ｘ線検出器７ｂで検出したＸ線強度のピーク部の
波形 ４０ 鉛箔 ４１ 中間物質 ４２ 集束点 ４３ Ｘ線管焦点 ４４ フィルム ４５ 鉛箔の影の幅1 X-ray tube 2 Collimator 3 Subject 4 Grid 5 Intensifying screen 6 Film closely attached to the intensifying screen 7 X-ray detector 8 X-ray automatic exposure device 9 Current-voltage conversion circuit 10 Integrating circuit 11 Comparison circuit 12 Reference voltage setting device 13 X-ray Cutoff signal generation circuit 14 X-ray control circuit 15 High voltage generator 16 Adder 17 A / D converter 18 Information processing device 19 Motor driver 20a X-axis drive motor 20b Y-axis drive motor 21 X detected by the X-ray detector 7a Waveform of peak portion of line intensity 22 Waveform of peak portion of X-ray intensity detected by X-ray detector 7 40 Lead foil 41 Intermediate substance 42 Focusing point 43 X-ray tube focus 44 Film 45 Width of shadow of lead foil
Claims (2)
グリッドを透過するＸ線強度を測定する第１手段と、そ
の測定値を基に前記グリッドとＸ線放射源の位置合わせ
を行なう第２手段を有することを特徴とするＸ線撮影装
置。1. A first means for measuring the intensity of X-rays transmitted through a grid using an X-ray detector of an automatic X-ray exposure device, and positioning the grid and the X-ray radiation source based on the measured value. An X-ray imaging apparatus having a second means for performing.
グリッドを透過するＸ線強度を測定し、その測定値を基
に前記グリッドとＸ線放射源の位置合わせを行なうこと
を特徴とするＸ線撮影装置の位置合わせ方法。2. An X-ray detector of an automatic X-ray exposure device is used to measure the X-ray intensity transmitted through the grid, and the grid and the X-ray radiation source are aligned based on the measured value. And a method of aligning the X-ray imaging apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4308809A JPH06154207A (en) | 1992-11-18 | 1992-11-18 | Radiographic apparatus and positioning method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4308809A JPH06154207A (en) | 1992-11-18 | 1992-11-18 | Radiographic apparatus and positioning method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06154207A true JPH06154207A (en) | 1994-06-03 |
Family
ID=17985576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4308809A Pending JPH06154207A (en) | 1992-11-18 | 1992-11-18 | Radiographic apparatus and positioning method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06154207A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001340331A (en) * | 2000-06-06 | 2001-12-11 | Shimadzu Corp | Radiographic device |
| WO2002004932A1 (en) * | 2000-07-10 | 2002-01-17 | Hitachi Medical Corporation | X-ray measuring apparatus |
| JP2006075295A (en) * | 2004-09-08 | 2006-03-23 | Shimadzu Corp | X-ray imaging apparatus |
| JP2008086471A (en) * | 2006-09-29 | 2008-04-17 | Fujifilm Corp | X-ray radiographic apparatus |
| JP2011101686A (en) * | 2009-11-10 | 2011-05-26 | Shimadzu Corp | Radiographic apparatus |
| WO2012102052A1 (en) * | 2011-01-27 | 2012-08-02 | 富士フイルム株式会社 | Radiological imaging device and method |
-
1992
- 1992-11-18 JP JP4308809A patent/JPH06154207A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001340331A (en) * | 2000-06-06 | 2001-12-11 | Shimadzu Corp | Radiographic device |
| WO2002004932A1 (en) * | 2000-07-10 | 2002-01-17 | Hitachi Medical Corporation | X-ray measuring apparatus |
| JP2006075295A (en) * | 2004-09-08 | 2006-03-23 | Shimadzu Corp | X-ray imaging apparatus |
| JP2008086471A (en) * | 2006-09-29 | 2008-04-17 | Fujifilm Corp | X-ray radiographic apparatus |
| JP2011101686A (en) * | 2009-11-10 | 2011-05-26 | Shimadzu Corp | Radiographic apparatus |
| WO2012102052A1 (en) * | 2011-01-27 | 2012-08-02 | 富士フイルム株式会社 | Radiological imaging device and method |
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