JP2003024320A - Linear motion type x-ray tomography apparatus - Google Patents
Linear motion type x-ray tomography apparatusInfo
- Publication number
- JP2003024320A JP2003024320A JP2001213067A JP2001213067A JP2003024320A JP 2003024320 A JP2003024320 A JP 2003024320A JP 2001213067 A JP2001213067 A JP 2001213067A JP 2001213067 A JP2001213067 A JP 2001213067A JP 2003024320 A JP2003024320 A JP 2003024320A
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- subject
- ray
- ray imaging
- image
- enlargement ratio
- 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.)
- Granted
Links
- 238000003325 tomography Methods 0.000 title claims abstract description 27
- 230000002194 synthesizing effect Effects 0.000 claims abstract description 10
- 238000003384 imaging method Methods 0.000 claims description 101
- 238000000034 method Methods 0.000 claims description 7
- 238000010586 diagram Methods 0.000 description 17
- 239000010408 film Substances 0.000 description 4
- 230000014509 gene expression Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 229910004613 CdTe Inorganic materials 0.000 description 1
- 241001436793 Meru Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 210000003484 anatomy Anatomy 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- RPPBZEBXAAZZJH-UHFFFAOYSA-N cadmium telluride Chemical compound [Te]=[Cd] RPPBZEBXAAZZJH-UHFFFAOYSA-N 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 210000004513 dentition Anatomy 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000036346 tooth eruption Effects 0.000 description 1
Landscapes
- Apparatus For Radiation Diagnosis (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】この発明は、直線運動型X線
断層撮影装置に係り、特に撮影拡大率の異なる複数の撮
影像を用いて所望部位の断層面画像を容易に抽出するこ
とのできる直線運動型X線断層撮影装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion type X-ray tomography apparatus, and more particularly to a straight line which makes it possible to easily extract a tomographic plane image of a desired portion using a plurality of photographed images having different photographing magnifications. The present invention relates to a moving X-ray tomography apparatus.
【0002】[0002]
【従来の技術】X線断層撮影装置としての歯科用断層撮
影装置においては、リニア断層撮影法(線形断層撮影
法)が、一般的な断層撮影法として利用されている。こ
のリニア断層撮影法は、X線源(管球)とX線撮影手段
(フィルムカセット)とが相対して患者の回りを回転す
るが、X線源(管球)とX線撮影手段(フィルムカセッ
ト)とはX線の照射方向に動くことなく、X線源とX線
撮像手段との移動は、X線の照射方向とは直角方向に移
動し、断層域外を撮影と同時にボケさせる方法を採って
いる。2. Description of the Related Art A linear tomography method (linear tomography method) is used as a general tomography method in a dental tomography apparatus as an X-ray tomography apparatus. In this linear tomography, the X-ray source (tube) and the X-ray imaging means (film cassette) rotate around the patient while the X-ray source (tube) and the X-ray imaging means (film cassette) rotate. A cassette) does not move in the X-ray irradiation direction, but the X-ray source and the X-ray imaging means move in a direction perpendicular to the X-ray irradiation direction, and the outside of the tomographic region is blurred simultaneously with imaging. I am collecting.
【0003】また、このようなX線撮影装置としては、
例えば、特開平7−23939号公報に開示されてい
る。この公報に記載のものは、被写体にX線を発生する
X線源と、被写体を通過したX線を検出するX線撮像手
段とを、被写体を間にして相互に対向し、直線移動させ
ながらX線照射を行い、被写体の撮影像をX線撮像手段
で取り込みながらX線撮影を行うものである。Further, as such an X-ray imaging apparatus,
For example, it is disclosed in Japanese Patent Laid-Open No. 7-23939. In the device described in this publication, an X-ray source for generating X-rays on an object and an X-ray imaging means for detecting X-rays passing through the object are opposed to each other with the object in between and are linearly moved. The X-ray irradiation is performed, and the X-ray imaging is performed while the captured image of the subject is captured by the X-ray imaging means.
【0004】[0004]
【発明が解決しようとする課題】ところが、従来、X線
断層撮影装置においては、断層域が数mm程度と狭く、
フィルム上で、断層域を外れたX線源(管球)側又はX
線撮影手段(フィルムカセット)側のいずれかの解剖学
的構造がボケるため、目的部位を断層域に入れるために
は、患者の位置付けを正確に行わなければならない。However, in the conventional X-ray tomography apparatus, the tomographic region is as narrow as several mm,
On the film, X-ray source (tube) side or X outside the tomographic region
Since any anatomical structure on the side of the radiographic means (film cassette) is blurred, the patient must be accurately positioned in order to put the target site in the tomographic region.
【0005】また、1回の位置付けで幾通りかの断層領
域を少しづつずらした断層領域を得た場合であっても、
臼歯部の歯牙4本程度の断層領域しか得られず、口腔内
領域全体の断層撮影を一度に行うことは困難であった。Further, even when a slice area obtained by slightly shifting some slice areas by one positioning is obtained,
Only a tomographic region of about 4 teeth in the molar region was obtained, and it was difficult to perform tomography of the entire oral region at one time.
【0006】更に、特開平7−23939号公報のX線
撮影装置においては、X線源又はX線撮像手段のどちら
か一方を固定させた状態で、X線撮像手段の検出面に対
して垂直方向に移動させることによって、従来と同様
に、任意断面の断面像が再構成する。つまり、X線源又
はX線撮像手段のどちらか一方を移動して得られる各画
像は、X線源又はX線撮像手段のいずれかの位置に応じ
て決定される単純な比例関数に基づいて、拡大あるいは
縮小されて得られるものである。しかしながら、X線源
又はX線撮像手段のいずれか一方を固定して他方を移動
させることにより、発生する拡大率の変化(増加率又は
増加量)が任意断面の断面像再構成に与える影響につい
ては、述べられていない。Further, in the X-ray imaging apparatus disclosed in Japanese Patent Laid-Open No. 7-23939, with either one of the X-ray source and the X-ray imaging means fixed, the vertical direction with respect to the detection surface of the X-ray imaging means. By moving in the direction, the cross-sectional image of an arbitrary cross section is reconstructed as in the conventional case. That is, each image obtained by moving either the X-ray source or the X-ray imaging means is based on a simple proportional function determined according to the position of either the X-ray source or the X-ray imaging means. , Is obtained by being enlarged or reduced. However, by fixing one of the X-ray source and the X-ray imaging means and moving the other, the influence of the change in the enlargement ratio (increase ratio or increase amount) that occurs on the cross-sectional image reconstruction of an arbitrary cross-section. Is not mentioned.
【0007】また、断層撮影方法においては、所望部位
の位置決めは、容易ではなく、また、装置自体も複雑な
動きをしなければならず、更に、撮影時間も長く、再現
性を得るのも困難であり、このため、インプラント等を
埋設するのに、誤った情報を提供するおそれがあった。Further, in the tomographic imaging method, it is not easy to position a desired portion, and the apparatus itself has to make complicated movements. Further, the imaging time is long and reproducibility is difficult to obtain. Therefore, there is a possibility that incorrect information may be provided when implanting an implant or the like.
【0008】[0008]
【課題を解決するための手段】そこで、この発明は、上
述の不都合を除去するために、被写体にX線を発生する
X線源と前記被写体を通過したX線を検出するX線撮像
手段とが備えられたX線撮影構成体を設け、前記被写体
を間にして前記X線源と前記X線撮像手段とを一定距離
に相互に対向して前記X線撮影構成体を直線移動させる
直線移動駆動手段を設け、前記X線撮影構成体の直線移
動距離を計測する移動計測手段を設け、前記X線撮像手
段には撮影像を画く撮影画像部を設け、この撮影画像部
での撮影像を制御する撮影像制御手段を設け、前記撮影
画像部での撮影像の拡大率補正を行う拡大率補正手段を
設け、この拡大率補正手段で補正された撮影像を重ね合
わせて合成する撮影像合成手段を設けたことを特徴とす
る。In order to eliminate the above-mentioned inconvenience, the present invention comprises an X-ray source for generating X-rays on a subject and an X-ray imaging means for detecting X-rays passing through the subject. A linear movement for linearly moving the X-ray imaging structure with the object in between and the X-ray source and the X-ray imaging means facing each other at a constant distance. Driving means is provided, movement measuring means for measuring the linear movement distance of the X-ray imaging structure is provided, and the X-ray imaging means is provided with a photographed image section for drawing a photographed image. A photographic image control means for controlling is provided, a magnifying power correction means for correcting the magnifying power of the photographic image in the photographic image part is provided, and the photographic images corrected by the magnifying power correction means are superposed and combined. Means are provided.
【0009】[0009]
【発明の実施の形態】この発明は、被写体にX線を発生
するX線源と被写体を通過したX線を検出するX線撮像
手段とを、被写体を間にして相互に対向し、且つ、X線
源とX線撮像手段との距離を一定に設定し、X線撮影構
成体を直線移動させながらX線照射を行い、任意の時間
毎に被写体の撮影像をX線源撮像手段で取り込みながら
X線撮影を行い、このとき、被写体は予め固定されてい
るため、ある基準点を予め設定すれば、その基準点に合
わせて撮影像の拡大率は、各々の位置により決定され、
取り込まれた複数枚の撮影像を拡大又は縮小し、その撮
影像を重ね合わせて合成することにより、所望部位の断
層面画像を容易に生成することができる。BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, an X-ray source for generating X-rays on an object and an X-ray imaging means for detecting X-rays passing through the object are opposed to each other with the object in between, and The distance between the X-ray source and the X-ray imaging means is set constant, X-ray irradiation is performed while linearly moving the X-ray imaging structure, and a captured image of the subject is captured by the X-ray source imaging means at arbitrary time intervals. While performing X-ray photography, at this time, since the subject is fixed in advance, if a certain reference point is set in advance, the magnifying power of the captured image is determined according to each reference point,
It is possible to easily generate a tomographic plane image of a desired portion by enlarging or reducing the captured multiple captured images and superimposing the captured images and combining them.
【0010】[0010]
【実施例】以下図面に基づいてこの発明の実施例を詳細
且つ具体的に説明する。図1〜18は、この発明の実施
例を示すものである。図18において、2は例えば歯列
等の被写体Mの断層撮影を行う直線運動型X線断層撮影
装置である。この直線運動型X線断層撮影装置2におい
ては、被写体MにX線を発生するX線源4と被写体Mを
通過したX線を検出するX線撮像手段6とが備えられた
X線撮影構成体8を設け、被写体Mを間にしてX線源4
とX線撮像手段6とを一定距離に相互に対向してX線撮
影構成体8を直線移動させる直線移動駆動手段10を設
け、X線撮影構成体8の直線移動距離を計測する移動計
測手段12を設け、X線撮像手段6には撮影像を画く撮
影画像部6Aを設け、この撮影画像部6Aでの撮影像を
制御する撮影像制御手段14を設け、撮影画像部6Aで
の撮影像の拡大率補正を行う拡大率補正手段16を設
け、この拡大率補正手段16で補正された撮影像を重ね
合わせて合成する撮影像合成手段18を設け、これら撮
影像制御手段14と拡大率補正手段16と撮影像合成手
段18とを一体にした制御装置20を設けている。X線
撮影構成体8は、X線源4を保持する保持部8Aと、こ
の保持部8AとX線撮像手段6とを連結した連結部8B
とからなる。また、制御装置20には、X線源4と直線
移動駆動手段10と移動計測手段12とが連絡してい
る。Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 18 show an embodiment of the present invention. In FIG. 18, reference numeral 2 is a linear motion X-ray tomography apparatus for performing tomography of a subject M such as a dentition. The linear motion X-ray tomography apparatus 2 is provided with an X-ray imaging configuration including an X-ray source 4 that generates X-rays on a subject M and an X-ray imaging unit 6 that detects X-rays that have passed through the subject M. The X-ray source 4 is provided with the body 8 and the subject M in between.
And a X-ray imaging means 6 are opposed to each other at a constant distance, and a linear movement driving means 10 for linearly moving the X-ray imaging structure 8 is provided, and a movement measuring means for measuring the linear movement distance of the X-ray imaging structure 8. 12, the X-ray imaging means 6 is provided with a photographed image portion 6A for drawing a photographed image, and the photographed image control means 14 for controlling the photographed image in this photographed image portion 6A is provided, and the photographed image in the photographed image portion 6A is provided. Magnification ratio correcting means 16 for correcting the magnification ratio, and photographed image synthesizing means 18 for superimposing and synthesizing the photographed images corrected by the magnification ratio correcting means 16, and the photographed image control means 14 and the magnification ratio correcting means. A control device 20 in which the means 16 and the captured image synthesizing means 18 are integrated is provided. The X-ray imaging structure 8 has a holding portion 8A that holds the X-ray source 4, and a connecting portion 8B that connects the holding portion 8A and the X-ray imaging means 6.
Consists of. Further, the control device 20 is in communication with the X-ray source 4, the linear movement driving means 10, and the movement measuring means 12.
【0011】X線撮像手段6は、受光面22を有し、二
次元X線イメージセンサとしての画像センサー(例え
ば、TFT(Thin Film Transisto
r)、MOS(Metal Oxide Semico
nductor)、CCD(Charge Coupl
ed Device)、XII(X線イメージインテン
シファイア)、FPD(Flat Panel Det
ector)、CdTeセンサ(カドミウムテルルセン
サ)に代表されるいずれか)からなる。The X-ray image pickup means 6 has a light receiving surface 22 and is an image sensor (for example, a TFT (Thin Film Transistor) as a two-dimensional X-ray image sensor.
r), MOS (Metal Oxide Semico)
nductor), CCD (Charge Couple)
ed Device), XII (X-ray image intensifier), FPD (Flat Panel Det)
vector) and a CdTe sensor (one of which is represented by a cadmium tellurium sensor).
【0012】移動計測手段12には、被写体Mの断層面
位置に目印となる不透過性のアダプタ24が設けられて
いる。The movement measuring means 12 is provided with an impermeable adapter 24 which serves as a mark at the position of the tomographic plane of the subject M.
【0013】この移動計測手段12は、例えば、PSD
素子(Position Sensitive Det
ector)、エンコーダ、反射型位置計測装置等に代
表されるいずれかからなる。The movement measuring means 12 is, for example, a PSD.
Element (Position Sensitive Det
vector), an encoder, a reflection type position measuring device, or the like.
【0014】拡大率補正手段16は、任意の位置での撮
影像の一辺拡大率をGとし、この位置に重ね合わされる
複数の撮影像の拡大率をB1、B2、B3…とすると
き、補正係数をB1/G、B2/G、B3/G…とし、
撮影像合成手段18は、これらの補正された撮影像を重
ね合わせる機能を有する。The magnifying power correcting means 16 corrects when the magnifying power of one side of a photographed image at an arbitrary position is G and the magnifying powers of a plurality of photographed images superimposed at this position are B1, B2, B3 ... The coefficients are B1 / G, B2 / G, B3 / G ...
The captured image synthesizing means 18 has a function of superposing these corrected captured images.
【0015】X線撮像手段6の撮影画像部6Aは、連続
的に撮影する方式と任意時間毎に撮影する方式とを備え
ている。The photographed image section 6A of the X-ray image pickup means 6 has a method of continuously photographing and a method of photographing every arbitrary time.
【0016】次に、この実施例の作用を説明する。Next, the operation of this embodiment will be described.
【0017】直線運動型X線断層撮影装置2において
は、任意の断層画像を生成するものであり、図18に示
す如く、X線源4とX線撮像手段6の受光面22とを対
向配置し、そして、図17に示す如く、X線源4とX線
撮像手段6との相互間の距離を一定に保ちつつ、被写体
Mに対し拡大率の異なる撮影像を複数枚取得し(ステッ
プ102)、その後、任意断層面を決定し(ステップ1
04)、そして、この決定された任意断層面の撮影像の
拡大率に合わせて、各撮影像を拡大又は縮小し、任意断
層面の大きさに合わす拡大率補正の計算を行い(ステッ
プ106)、この補正された撮影像を重ね合わせ(ステ
ップ108)、断層像を生成する(ステップ110)。In the linear motion type X-ray tomography apparatus 2, an arbitrary tomographic image is generated, and as shown in FIG. 18, the X-ray source 4 and the light receiving surface 22 of the X-ray imaging means 6 are arranged so as to face each other. Then, as shown in FIG. 17, while keeping the distance between the X-ray source 4 and the X-ray imaging means 6 constant, a plurality of photographed images with different magnifications are obtained for the subject M (step 102). ), And then determine the arbitrary fault plane (Step 1
04), and enlarges or reduces each captured image in accordance with the determined enlargement ratio of the captured image of the arbitrary tomographic plane, and performs magnification ratio correction calculation to match the size of the arbitrary tomographic plane (step 106). Then, the corrected photographed images are superposed (step 108) to generate a tomographic image (step 110).
【0018】この実施例においては、図2に示す如く、
X線源4から受光面22までの距離を一定とし、且つ、
被写体MをX線源4とX線撮像手段6の受光面22との
間に置くことによって、拡大率の変化を大きくとること
を可能にする。この図2においては、縦軸に一辺拡大
率、横軸にX線源4から被写体Mまでの距離を示し、本
願発明と特開平7−23939号公報の発明とを比較し
ている。In this embodiment, as shown in FIG.
The distance from the X-ray source 4 to the light receiving surface 22 is constant, and
By placing the subject M between the X-ray source 4 and the light-receiving surface 22 of the X-ray imaging means 6, it is possible to make a large change in the enlargement ratio. In FIG. 2, the vertical axis represents the one-side magnification ratio and the horizontal axis represents the distance from the X-ray source 4 to the subject M, and the invention of the present application and the invention of JP-A-7-23939 are compared.
【0019】本願発明においては、図1に示す如く、被
写体Mを間にしてX線源4とX線撮像手段6とを一定距
離に保ちつつ、被写体MからX線撮像手段6の受光面2
2までの距離Bの初期値を20mmとし、この距離Bを
20mm〜980mmまで移動させ、一辺拡大率を増加
させていく。このとき、全長はA+B=1000mmを
常に保っている。一方、特開平7−23939号公報の
発明のものは、図19に示す如く、被写体Mを間にして
X線撮像手段202及び被写体Mを固定したままX線源
204を移動させて行く。被写体MからX線撮像手段2
02までの距離Bを一定に保ったまま、X線源204か
ら被写体Mまでの距離Aを被写体Mに近づけていく。こ
の動きをグラフ化すると、図2の曲線のようになる。In the present invention, as shown in FIG. 1, the X-ray source 4 and the X-ray image pickup means 6 are kept at a constant distance with the object M in between, and the light-receiving surface 2 of the X-ray image pickup means 6 from the subject M.
The initial value of the distance B up to 2 is set to 20 mm, the distance B is moved from 20 mm to 980 mm, and the one side expansion rate is increased. At this time, the total length is always A + B = 1000 mm. On the other hand, in the invention disclosed in Japanese Patent Laid-Open No. 7-23939, as shown in FIG. 19, the X-ray source 204 is moved with the subject M in between while the X-ray imaging means 202 and the subject M are fixed. X-ray imaging means 2 from subject M
The distance A from the X-ray source 204 to the subject M is brought closer to the subject M while keeping the distance B up to 02 constant. When this movement is graphed, it becomes like the curve in FIG.
【0020】このとき、この従来の図19においては、
図1との比較のために、Bを20mm一定、Aを980
mm〜20mmまで変化させている。At this time, in this conventional FIG.
For comparison with FIG. 1, B is constant at 20 mm and A is 980
It is changed from mm to 20 mm.
【0021】この結果、図2に示す如く、本願発明にお
いては、少ない移動距離で一辺拡大率の大幅な変化が得
られるが、特開平7−23939号公報の発明において
は、一辺拡大率の多少の変化しか得られないことが分か
る。As a result, as shown in FIG. 2, in the present invention, a large change in the one-side enlargement ratio can be obtained with a small moving distance, but in the invention of Japanese Patent Laid-Open No. 7-23939, the one-side enlargement ratio is slightly different. It turns out that only the change of can be obtained.
【0022】以下に、本願発明の一辺拡大率の変化につ
いて、詳細に説明する。The change in the one side enlargement ratio of the present invention will be described in detail below.
【0023】つまり、図3に示す如く、X線を発生する
X線源4と、被写体Mを通過したX線を検出するX線撮
像手段6の受光面22とを被写体Mを間にして直線状に
配置する。このとき、X線源4とX線撮像手段6の受光
面22の相互間の距離を一定に保つ。また、被写体M
は、ある大きさを持ったものである。That is, as shown in FIG. 3, the X-ray source 4 for generating X-rays and the light-receiving surface 22 of the X-ray imaging means 6 for detecting the X-rays passing through the subject M are straight lines with the subject M in between. Arranged in a shape. At this time, the distance between the X-ray source 4 and the light-receiving surface 22 of the X-ray imaging means 6 is kept constant. Also, the subject M
Is a certain size.
【0024】次に、X線源4から被写体Mまでの距離を
A、被写体MからX線撮像手段6の受光面22までの距
離をBとする。このとき、被写体Mでの一辺拡大率G2
は、
G2=(A+B)/A……(1)
となる。Next, the distance from the X-ray source 4 to the subject M is A, and the distance from the subject M to the light receiving surface 22 of the X-ray imaging means 6 is B. At this time, the one side enlargement ratio G 2 of the subject M
Becomes G 2 = (A + B) / A (1)
【0025】そして、被写体Mでの面積拡大率GS
2は、
GS2=(G2)2={(A+B)/A}2 ……(2)
となる。Then, the area expansion rate GS of the subject M
2 is GS 2 = (G 2 ) 2 = {(A + B) / A} 2 (2).
【0026】図4は、複数の被写体M1、M2、M3で
ある歯列の断層撮影を行う本願発明の実施例である。こ
の被写体M1、M2、M3はそれぞれ大きさ、X線吸収
率は同一とし、X線源4から被写体M1、M2、M3に
照射されるX線強度が均一なものとする。被写体M1、
M2、M3の透過後にX線撮像手段6の受光面22に投
影される信号強度は、面積成分と黒化度成分とに分割さ
れる。面積拡大率が大きいもの程、投影面積は大きくな
り、黒化度成分は小さくなる。FIG. 4 shows an embodiment of the present invention in which tomography of a plurality of objects M1, M2 and M3 is performed. The subjects M1, M2, and M3 have the same size and the same X-ray absorption rate, and the X-ray intensity emitted from the X-ray source 4 to the subjects M1, M2, and M3 is uniform. Subject M1,
The signal intensity projected on the light receiving surface 22 of the X-ray imaging means 6 after passing through M2 and M3 is divided into an area component and a blackening component. The larger the area expansion rate, the larger the projected area and the smaller the blackening component.
【0027】次に、被写体M2に関して、信号強度を求
める。被写体M2に照射される信号強度をIEとし、被
写体M2の面積をS0(S0≠0)とし、X線撮像手段
6の受光面22での被写体M2の面積をS2としたと
き、X線撮像手段6の受光面22での被写体M2の面積
S2は、
S2=S0*GS2
で示される。Next, the signal strength of the subject M2 is calculated.
Meru. I is the signal intensity applied to the subject M2EAnd the cover
The area of image M2 is S0(S0≠ 0), and X-ray imaging means
The area of the subject M2 on the light receiving surface 22 of 6 is STwoAnd
Area of the subject M2 on the light receiving surface 22 of the X-ray imaging means 6
STwoIs
STwo= S0* GSTwo
Indicated by.
【0028】そして、面積拡大率GS2によってX線撮
像手段6の受光面22が受ける信号強度ID2は、次式
となる。
ID2=IE/S2
=IE/(S0*GS2)
=IE/{S0*(G2)2}
=IE/[S0*{(A+B)/A}2 ]……(3)The area expansion rate GSTwoBy x-ray
Signal intensity I received by the light receiving surface 22 of the image means 6D2Is the expression
Becomes
ID2= IE/ STwo
= IE/ (S0* GSTwo)
= IE/ {S0* (GTwo)Two}
= IE/ [S0* {(A + B) / A}Two ] …… (3)
【0029】同様に、被写体M1に関して、信号強度を
求める。ここでも、被写体M1、M2、M3の各被写体
の面積は、全て同一のS0(S0≠0)とし、また、被
写体M1、M2、M3に照射される信号強度も、全て同
一のIEとする。被写体M2を中心にして、X線撮像手
段6の受光面22と平行に引いた線をY軸、この受光面
22と垂直に引いた線をX軸とする。被写体M1は、被
写体M2から距離Lだけ、X線源4側に配置されてい
る。Similarly, the signal strength of the subject M1 is obtained. Here again, the areas of the subjects M1, M2, and M3 are all the same S 0 (S 0 ≠ 0), and the signal intensities irradiated to the subjects M1, M2, and M3 are all the same I E And A line drawn in parallel with the light receiving surface 22 of the X-ray imaging means 6 around the subject M2 is taken as a Y axis, and a line drawn perpendicularly to the light receiving surface 22 is taken as an X axis. The subject M1 is arranged on the X-ray source 4 side a distance L from the subject M2.
【0030】よって、X線源4から被写体M1までの距
離はA−L、被写体M1からX線撮像手段6の受光面2
2までの距離はB+Lで表される。このとき、被写体M
1の一辺拡大率G1は、
となる。Therefore, the distance from the X-ray source 4 to the subject M1 is A-L, and the light-receiving surface 2 of the X-ray imaging means 6 from the subject M1.
The distance to 2 is represented by B + L. At this time, the subject M
One side expansion ratio G 1 of 1 is Becomes
【0031】そして、被写体M1での面積拡大率GS1
は、
GS1=(G1)2={(A+B)/(A−L)}2 ……(5)
となる。Then, the area expansion rate GS 1 of the subject M1
Becomes GS 1 = (G 1 ) 2 = {(A + B) / (AL)} 2 (5).
【0032】次に、被写体M1に関して信号強度を求め
ると、X線撮像手段6の受光面22での被写体M1の面
積をS1とするとき、X線撮像手段6の受光面22での
被写体M1の面積S1は、
S1=S0*GS1
で示される。Next, the signal strength of the subject M1 is calculated.
Then, the surface of the subject M1 on the light receiving surface 22 of the X-ray imaging means 6
Product S1, The light receiving surface 22 of the X-ray imaging means 6
Area S of subject M11Is
S1= S0* GS1
Indicated by.
【0033】そして、面積拡大率GS1によってX線撮
像手段6の受光面22が受ける信号強度ID1は、次式
となる。
ID1=IE/S1
=IE/(S0*GS1)
=IE/{S0*(G1)2}
=IE/〔S0*{(A+B)/(A−L)}2〕……(6)The signal intensity I D1 received by the light receiving surface 22 of the X-ray imaging means 6 by the area enlargement ratio GS 1 is given by the following equation. I D1 = I E / S 1 = I E / (S 0 * GS 1 ) = I E / {S 0 * (G 1 ) 2 } = I E / [S 0 * {(A + B) / (A−L) )} 2 ] …… (6)
【0034】同様に、被写体M3に関して、信号強度を
求める。ここでも、被写体面積S0及び被写体M3に照
射される信号強度IEは、同一であるから、被写体M3
は、被写体M2から距離LだけX線撮像手段6の受光面
22側に配置されている。Similarly, the signal strength of the subject M3 is obtained. Again, since the subject area S 0 and the signal intensity I E applied to the subject M3 are the same, the subject M3
Are arranged on the light receiving surface 22 side of the X-ray imaging means 6 by a distance L from the subject M2.
【0035】よって、X線源4から被写体M3までの距
離はA+L、被写体M3からX線撮像手段6の受光面2
2までの距離はB−Lで表される。このとき、被写体M
3の一辺拡大率G3は、
となる。Therefore, the distance from the X-ray source 4 to the subject M3 is A + L, and the light receiving surface 2 of the X-ray imaging means 6 from the subject M3.
The distance to 2 is represented by BL. At this time, the subject M
One side expansion rate G 3 of 3 is Becomes
【0036】そして、被写体M3での面積拡大率GS3
は、
GS3=(G3)2={(A+B)/(A+L)}2 ……(8)
となる。Then, the area expansion rate GS 3 of the subject M3
Becomes GS 3 = (G 3 ) 2 = {(A + B) / (A + L)} 2 (8).
【0037】次に、被写体M3に関して信号強度を求め
ると、X線撮像手段6の受光面22での被写体M3の面
積をS3とするとき、X線撮像手段6の受光面22での
被写体M3の面積S3は、
S3=S0*GS3
で示される。Next, the signal strength of the subject M3 is calculated.
Then, the surface of the subject M3 on the light receiving surface 22 of the X-ray imaging means 6
Product SThree, The light receiving surface 22 of the X-ray imaging means 6
Area S of subject M3ThreeIs
SThree= S0* GSThree
Indicated by.
【0038】そして、面積拡大率GS3によってX線撮
像手段6の受光面22が受ける信号強度ID3は、次式
となる。
ID3=IE/S3
=IE/(S0*GS3)
=IE/{S0*(G3)2}
=IE/[S0*{(A+B)/(A+L)}2]……(9)Area expansion rate GSThreeBy x-ray
Signal intensity I received by the light receiving surface 22 of the image means 6D3Is the expression
Becomes
ID3= IE/ SThree
= IE/ (S0* GSThree)
= IE/ {S0* (GThree)Two}
= IE/ [S0* {(A + B) / (A + L)}Two] …… (9)
【0039】ここで、実状に則したA,B,Lの各距離
値を設定し、X線源4とX線撮像手段6の受光面22と
の距離を一定に保ったまま、被写体M1、M2、M3の
位置をX線源4に接近した位置(A<B)、X線源4及
びX線撮像手段6の受光面22からの距離が同じ位置
(A=B)、X線撮像手段6の受光面22に接近した位
置(A>B)について、一辺拡大率、面積拡大率および
X線撮像手段6の受光面22が受ける信号強度の例を、
以下に示す(図5参照)。Here, the respective distance values of A, B, L according to the actual condition are set, and the distance between the X-ray source 4 and the light-receiving surface 22 of the X-ray imaging means 6 is kept constant, and the subject M1, The positions of M2 and M3 are close to the X-ray source 4 (A <B), the positions of the X-ray source 4 and the light-receiving surface 22 of the X-ray imaging unit 6 are the same (A = B), and the X-ray imaging unit. 6 at the position close to the light receiving surface 22 (A> B), an example of the one side magnification, the area enlargement ratio, and the signal intensity received by the light receiving surface 22 of the X-ray imaging means 6,
It is shown below (see FIG. 5).
【0040】<条件1>被写体M1、M2、M3の面積
をS0(S0≠0)とし、A=250mm、B=750
mm、L=10mm、被写体M1、M2、M3に照射さ
れる信号強度をIEとする。<Condition 1> When the areas of the subjects M1, M2 and M3 are S 0 (S 0 ≠ 0), A = 250 mm, B = 750
mm, L = 10 mm, and the signal intensity applied to the subjects M1, M2, and M3 is I E.
【0041】被写体M1、M2、M3の各々の一辺拡大
率については、被写体M1の一辺拡大率G11は、
(4)式より、
G11=(250+750)/(250−10)=4.
1667
被写体M2の一辺拡大率G12は、(1)式より、
G12=(250+750)/250=4.0000
被写体M3の一辺拡大率G13は、は、(7)式より、
G13=(250+750)/(250+10)=3.
8462
となる。Regarding the one side enlargement ratio of each of the subjects M1, M2 and M3, the one side enlargement ratio G 11 of the subject M1 is
From the equation (4), G 11 = (250 + 750) / (250-10) = 4.
1667 The one-sided enlargement ratio G 12 of the subject M2 is G 12 = (250 + 750) /250=4.0000 from the formula (1) The one-sided enlargement ratio G 13 of the subject M3 is G 13 = from the formula (7) (250 + 750) / (250 + 10) = 3.
It becomes 8462.
【0042】被写体M1、M2、M3の各々の面積拡大
率については、被写体M1の面積拡大率GS11は、
(5)式より、
GS11=(G11)2=17.3611
被写体M2の面積拡大率GS12は、(2)式より、
GS12=(G12)2=16.0000
被写体M3の面積拡大率GS13は、(8)式より、
GS13=(G13)2=14.7929
となる。Regarding the area expansion rate of each of the objects M1, M2 and M3, the area expansion rate GS 11 of the object M1 is
From the formula (5), GS 11 = (G 11 ) 2 = 17.3611 The area expansion ratio GS 12 of the subject M2 is calculated from the formula (2) as follows: GS 12 = (G 12 ) 2 = 16.0000 The area of the subject M3 The expansion rate GS 13 is GS 13 = (G 13 ) 2 = 14.7929 from the equation (8).
【0043】次に、夫々の面積拡大率によってX線撮像
手段6の受光面22が受ける信号強度IDを求める。Next, the signal intensity I D received by the light-receiving surface 22 of the X-ray imaging means 6 is obtained by the area enlargement ratio.
【0044】被写体M1について、面積拡大率17.3
611によってX線撮像手段6の受光面22が受ける信
号強度をID11とすると、(6)式より、
ID11=IE/(S0*GS11)
=IE/{S0*(G11)2}
=IE/(17.3611*S0)
=0.0576(IE/S0)
となる。For the subject M1, the area expansion rate 17.3
If the signal strength of the light-receiving surface 22 receives the X-ray imaging means 6 and I D11 by 611, from equation (6), I D11 = I E / ( S 0 * GS 11) = I E / {S 0 * (G 11) 2} = I E /(17.3611*S 0) = 0.0576 a (I E / S 0).
【0045】被写体M2について、面積拡大率16.0
000によってX線撮像手段6の受光面22が受ける信
号強度をID12とすると、(3)式より、
ID12 =IE/(S0*GS12)
=IE/{S0*(G12)2}
=IE/(16.0000*S0)
=0.0625(IE/S0)
となる。For the subject M2, the area expansion rate is 16.0.
000, the signal intensity received by the light-receiving surface 22 of the X-ray imaging means 6 is I D12. From equation (3), I D12 = I E / (S 0 * GS 12 ) = I E / {S 0 * (G 12) 2} = I E /(16.0000*S 0) = 0.0625 a (I E / S 0).
【0046】被写体M3について、面積拡大率4.79
29によってX線撮像手段6の受光面22が受ける信号
強度をID13とすると、(9)式より、
ID13=IE/(S0*GS13)
=IE/{S0*(G13)2}
=IE/(14.7929*S0)
=0.0676(IE/S0)
となる。For the subject M3, the area expansion rate is 4.79.
Assuming that the signal intensity received by the light receiving surface 22 of the X-ray imaging unit 6 by 29 is I D13 , I D13 = I E / (S 0 * GS 13 ) = I E / {S 0 * (G 13 ) 2 } = I E /(14.7929*S 0 ) = 0.0676 (I E / S 0 ).
【0047】<条件2>被写体M1、M2、M3の面積
をS0(S0≠0)とし、A=500mmとし、B=5
00mmとし、L=10mmとし、被写体M1、M2、
M3に照射される信号強度をIEとする。<Condition 2> The areas of the subjects M1, M2 and M3 are S 0 (S 0 ≠ 0), A = 500 mm, and B = 5.
00 mm, L = 10 mm, subjects M1, M2,
The signal intensity applied to M3 is I E.
【0048】被写体M1、M2、M3の各々の一辺拡大
率については、被写体M1の一辺拡大率G21は、
(4)式より、
G21=(500+500)/(500−10)=2.
0408
被写体M2の一辺拡大率G22は、(1)式より、
G22=(500+500)/500=2.0000
被写体M3の一辺拡大率G23は、(7)式より
G23=(500+500)/(500+10)=1.
9608
となる。[0048] For the object M1, M2, M3 respectively side magnification of a side enlargement factor G 21 of the object M1 is
From the equation (4), G 21 = (500 + 500) / (500-10) = 2.
Side enlargement factor G 22 of 0408 subjects M2 is (1) from the equation, one side enlargement factor G 23 of the G 22 = (500 + 500) /500=2.0000 object M3 is, (7) G 23 = ( 500 + 500) from the equation / (500 + 10) = 1.
It becomes 9608.
【0049】被写体M1、M2、M3の各々の面積拡大
率については、被写体M1の面積拡大率GS21は、
(5)式より、
GS21=(G21)2=4.1649
被写体M2の面積拡大率GS22は、(2)式より、
GS22=(G22)2=4.0000
被写体M3の面積拡大率GS23は、(8)式より、
GS23=(G23)2=3.8447
となる。Regarding the area expansion rate of each of the objects M1, M2, M3, the area expansion rate GS 21 of the object M1 is
From the formula (5), GS 21 = (G 21 ) 2 = 4.1649 The area expansion ratio GS 22 of the subject M2 is calculated from the formula (2) as follows: GS 22 = (G 22 ) 2 = 4.0000 Area of the subject M3 The enlargement ratio GS 23 is GS 23 = (G 23 ) 2 = 3.8447 from the equation (8).
【0050】次に、夫々の面積拡大率によってX線撮像
手段6の受光面22が受ける信号強度IDを求める。Next, the signal intensity I D received by the light receiving surface 22 of the X-ray image pickup means 6 is obtained by the area enlargement ratio.
【0051】被写体M1について、面積拡大率4.16
49によってX線撮像手段6の受光面22が受ける信号
強度をID21とすると、(6)式より、
ID21=IE/(S0*GS21)
=IE/{S0*(G21)2}
=IE/(4.1649*S0)
=0.2401(IE/S0)
となる。For the subject M1, the area expansion rate 4.16.
Assuming that the signal intensity received by the light receiving surface 22 of the X-ray imaging means 6 by 49 is I D21 , from the equation (6), I D21 = I E / (S 0 * GS 21 ) = I E / {S 0 * (G 21) 2} = I E /(4.1649*S 0) = 0.2401 a (I E / S 0).
【0052】被写体M2について、面積拡大率4.00
00によってX線撮像手段6の受光面22が受ける信号
強度をID22とすると、(3)式より、
ID22=IE/(S0*GS22)
=IE/{S0*(G22)2}
=IE/(4.0000*S0)
=0.2500(IE/S0)
となる。For the subject M2, the area expansion rate 4.00
If the signal strength of the light-receiving surface 22 receives the X-ray imaging means 6 by 00 and I D22, (3) from the equation, I D22 = I E / ( S 0 * GS 22) = I E / {S 0 * (G 22) 2} = I E /(4.0000*S 0) = 0.2500 a (I E / S 0).
【0053】被写体M3について、面積拡大率3.84
47によってX線撮像手段6の受光面22が受ける信号
強度をID23とすると、(9)式より、
ID23=IE/(S0*GS23)
=IE/{S0*(G23)2}
=IE/(3.8447*S0)
=0.2601(IE/S0)
となる。For the subject M3, the area expansion rate is 3.84.
Assuming that the signal intensity received by the light-receiving surface 22 of the X-ray imaging means 6 by 47 is I D23 , I D23 = I E / (S 0 * GS 23 ) = I E / {S 0 * (G 23) 2} = I E /(3.8447*S 0) = 0.2601 a (I E / S 0).
【0054】<条件3>被写体M1、M2、M3の面積
をS0(S0≠0)とし、A=750mmとし、B=2
50mmとし、L=10mmとし、被写体M1、M2、
M3に照射される信号強度をIEとする。<Condition 3> The areas of the subjects M1, M2, and M3 are S 0 (S 0 ≠ 0), A = 750 mm, and B = 2.
50 mm, L = 10 mm, and subjects M1, M2,
The signal intensity applied to M3 is I E.
【0055】被写体M1、M2、M3の各々の一辺拡大
率については、被写体M1の一辺拡大率G31は、
(4)式より、
G31=(750+250)/(750−10)=1.
3514
被写体M2の一辺拡大率G32は、(1)式より、
G32=(750+250)/750=1.3333
被写体M3の一辺拡大率G33は、(7)式より、
G33=(750+250)/(750+10)=1.
3158
となる。Regarding the one side enlargement ratio of each of the subjects M1, M2 and M3, the one side enlargement ratio G 31 of the subject M1 is
From the equation (4), G 31 = (750 + 250) / (750-10) = 1.
3514 The one-sided enlargement ratio G 32 of the subject M2 is G 32 = (750 + 250) /750=1.3333 from the formula (1). The one-sided enlargement ratio G 33 of the subject M3 is G 33 = (750 + 250) from the formula (7). ) / (750 + 10) = 1.
It becomes 3158.
【0056】被写体M1、M2、M3の各々の面積拡大
率については、被写体M1の面積拡大率GS31は、
(5)式より、
GS31=(G31)2=1.8262
被写体M2の面積拡大率GS32は、(2)式より、
GS32=(G32)2=1.7778
被写体M3の面積拡大率GS33は、(8)式より、
GS33=(G33)2=1.7313
となる。Regarding the area expansion rate of each of the objects M1, M2 and M3, the area expansion rate GS 31 of the object M1 is
From the formula (5), GS 31 = (G 31 ) 2 = 1.8262 The area expansion ratio GS 32 of the subject M2 is calculated from the formula (2) as follows: GS 32 = (G 32 ) 2 = 1.77778 The area of the subject M3 The expansion rate GS 33 is GS 33 = (G 33 ) 2 = 1.7313 from the equation (8).
【0057】次に、夫々の面積拡大率によってX線撮像
手段6の受光面22が受ける信号強度IDを求める。Next, the signal intensity I D received by the light-receiving surface 22 of the X-ray imaging means 6 is obtained by the area enlargement ratio.
【0058】被写体M1について、面積拡大率1.82
62によってX線撮像手段6の受光面22が受ける信号
強度をID31とすると、(6)式より、
ID31=IE/(S0*GS31)
=IE/{S0*(G31)2}
=IE/(1.8262*S0)
=0.5476(IE/S0)
となる。For the subject M1, the area expansion rate 1.82
Assuming that the signal intensity received by the light receiving surface 22 of the X-ray imaging means 6 by 62 is I D31 , from the equation (6), I D31 = I E / (S 0 * GS 31 ) = I E / {S 0 * (G 31) 2} = I E /(1.8262*S 0) = 0.5476 a (I E / S 0).
【0059】被写体M2について、面積拡大率1.77
78によってX線撮像手段6の受光面22が受ける信号
強度をID32とすると、(3)式より、
ID32=IE/(S0*GS32)
=IE/{S0*(G32)2}
=IE/(1.7778*S0)
=0.5625(IE/S0)
となる。With respect to the subject M2, the area expansion rate is 1.77.
Assuming that the signal intensity received by the light receiving surface 22 of the X-ray imaging means 6 by 78 is I D32 , I D32 = I E / (S 0 * GS 32 ) = I E / {S 0 * (G 32) 2} = I E /(1.7778*S 0) = 0.5625 a (I E / S 0).
【0060】被写体M3について、面積拡大率1.73
13によってX線撮像手段6の受光面22が受ける信号
強度をID33とすると、(9)式より、
ID33=IE/(S0*GS33)
=IE/{S0*(G33)2}
=IE/(1.7313*S0)
=0.5776(IE/S0)
となる。For the subject M3, the area expansion rate 1.73
Supposing that the signal intensity received by the light receiving surface 22 of the X-ray imaging means 6 by 13 is I D33 , from the formula (9), I D33 = I E / (S 0 * GS 33 ) = I E / {S 0 * (G 33) 2} = I E /(1.7313*S 0) = 0.5776 a (I E / S 0).
【0061】以上の結果をまとめると、図6の様にな
る。The above results are summarized as shown in FIG.
【0062】この図6においては、被写体M1の面積拡
大率は17.3611から1.8262(一辺拡大率は
4.1667から1.3514)へ、被写体M2の面積
拡大率は16.0000から1.7778(一辺拡大率
は4.0000から1.3333)へ、被写体M3の面
積拡大率は14.7929から1.7313(一辺拡大
率は3.8462から1.3158)へと大きく変化
し、このときのX線撮像手段6の受光面22での信号強
度は各々、0.0576(IE/S0)から0.547
6(IE/S0)へ、0.0625(IE/S0)から
0.5625(I E/S0)へ、0.0676(IE/
S0)から0.5776(IE/S0)へと、変化して
いる。In FIG. 6, the area of the subject M1 is expanded.
The large rate is from 17.3611 to 1.8262 (one side expansion rate is
Area of subject M2 from 4.1667 to 1.3514)
The expansion rate is from 16.0000 to 1.7778 (One side expansion rate
From 4.0000 to 1.3333), the surface of subject M3
Product expansion rate is from 14.7929 to 1.7313 (One side expansion
The rate greatly changed from 3.8462 to 1.3158)
However, at this time, the signal intensity on the light receiving surface 22 of the X-ray imaging means 6 is increased.
Each degree is 0.0576 (IE/ S0) To 0.547
6 (IE/ S0) To 0.0625 (IE/ S0) From
0.5625 (I E/ S0) To 0.0676 (IE/
S0) To 0.5776 (IE/ S0)
There is.
【0063】次に、条件2の被写体M2を、求める断層
面とした時の画像再構築の例を示す。Next, an example of image reconstruction when the subject M2 under condition 2 is the tomographic plane to be obtained will be described.
【0064】<条件1>の画像について、まず、条件2
での被写体M2の一辺拡大率G22に対する条件1での
被写体M2の一辺拡大率G12の補正係数をk12とす
ると、補正係数k12と一辺拡大率との関係は、次式で
示される。
(G12*k12)/G22=1Regarding the image of <condition 1>, first, the condition 2
Assuming that the correction coefficient of the one-side expansion rate G 12 of the subject M2 under the condition 1 with respect to the one-side expansion rate G 22 of the subject M2 is k 12 , the relationship between the correction coefficient k 12 and the one-side expansion rate is expressed by the following equation. . (G 12 * k 12 ) / G 22 = 1
【0065】よって、条件2での被写体M2の一辺拡大
率に対する条件1での被写体M2の一辺拡大率の補正係
数k12は、
k12=G22/G12
=2.0000/4.0000=0.5000
となる。Therefore, one side of the subject M2 under condition 2 is enlarged.
Correction factor for the one-side expansion ratio of the subject M2 under the condition 1 for the ratio
A few k12Is
k12= G22/ G12
= 2.0000 / 4.0000 = 0.5000
Becomes
【0066】従って、条件1の被写体M1、M2、M3
の各々の一辺拡大率を、0.5000倍する。Therefore, the subjects M1, M2, M3 of condition 1
Each side expansion factor is multiplied by 0.5000.
【0067】被写体M1の補正後の一辺拡大率G11’
は、
G11’=4.1667* 0.5000=2.083
4
となる。One side enlargement ratio G 11 ' after correction of the subject M1
Is G 11 ′ = 4.1667 * 0.5000 = 2.083
4.
【0068】X線撮像手段6の受光面22が受ける信号
強度ID11、被写体M1の面積拡大率GS11は、補
正後信号強度ID11’、被写体M1の補正後面積拡大
率GS11’に夫々置き換えられる。よって、(6)式
より、
ID11’=IE/(S0*GS11’)
=IE/{S0*(G11’)2}
=IE/(S0*4.3406)
=0.2304(IE/S0)
となる。The signal intensity I D11 received by the light-receiving surface 22 of the X-ray imaging means 6 and the area enlargement ratio GS 11 of the subject M1 are respectively the corrected signal intensity I D11 ' and the corrected area enlargement ratio GS 11' of the subject M1. Will be replaced. Therefore, from the equation (6), I D11 ′ = I E / (S 0 * GS 11 ′ ) = I E / {S 0 * (G 11 ′ ) 2 } = I E / (S 0 * 4.3406) = 0.2304 a (I E / S 0).
【0069】被写体M2の補正後の一辺拡大率G12’
は、
G12’=4.0000* 0.5000=2.000
0
となる。One-side magnification G 12 ' after correction of subject M2
Is G 12 ′ = 4.0000 * 0.5000 = 0.200.
It becomes 0.
【0070】X線撮像手段6の受光面22が受ける信号
強度ID12、被写体M2の面積拡大率GS12は、補
正後信号強度ID12’、被写体M2の補正後面積拡大
率GS12’に夫々置き換えられる。よって、(3)式
より、
ID12’=IE/(S0*GS12’)
=IE/{S0*(G12’)2}
=IE/(S0*4.0000)
=0.2500(IE/S0)
となる。The signal intensity I D12 received by the light receiving surface 22 of the X-ray imaging means 6 and the area enlargement ratio GS 12 of the subject M2 are respectively the corrected signal intensity I D12 ' and the corrected area enlargement ratio GS 12' of the subject M2. Will be replaced. Therefore, from the equation (3), I D12 ′ = I E / (S 0 * GS 12 ′ ) = I E / {S 0 * (G 12 ′ ) 2 } = I E / (S 0 * 4.0000) = 0.2500 a (I E / S 0).
【0071】被写体M3の補正後の一辺拡大率G13’
は、
G13’=3.8462* 0.5000=1.923
1
となる。One-side magnification G 13 ' after correction of subject M3
Is G 13 ′ = 3.8462 * 0.5000 = 1.923
It becomes 1.
【0072】X線撮像手段6の受光面22が受ける信号
強度ID13、被写体M3の面積拡大率GS13は、補
正後信号強度ID13’、被写体M3の補正後面積拡大
率GS13’に夫々置き換えられる。よって、(9)式
より、
ID13’=IE/(S0*GS13’)
=IE/{S0*(G13’)2}
=IE/(S0*3.6983)
=0.2704(IE/S0)
となる。The signal intensity I D13 received by the light-receiving surface 22 of the X-ray imaging means 6 and the area enlargement ratio GS 13 of the subject M3 are respectively the corrected signal intensity I D13 ' and the corrected area enlargement ratio GS 13' of the subject M3. Will be replaced. Therefore, from the equation (9), I D13 ′ = I E / (S 0 * GS 13 ′ ) = I E / {S 0 * (G 13 ′ ) 2 } = I E / (S 0 * 3.6983) = 0.2704 (I E / S 0 ).
【0073】<条件2>の画像について、被写体M2の
一辺拡大率は基準であるため、被写体M1、M3もその
ままの一辺拡大率であり、信号強度IDもそのままの値
となる。被写体M1の一辺拡大率G21は、G21=
2.0408となる。被写体M1の信号強度I
D21は、ID21=0.2401(IE/S0)とな
る。被写体M2の一辺拡大率G22は、G22=2.0
000となる。被写体M2の信号強度ID12は、I
D12=0.2500(IE/S0)となる。被写体M
3の一辺拡大率G23は、G23=1.9608とな
る。被写体M3の信号強度ID13は、ID13=0.2
601(IE/S0)となる。In the image of <Condition 2>, since the one-side enlargement ratio of the subject M2 is a reference, the subject M1 and M3 are also the one-side enlargement ratio, and the signal intensity I D is also the same value. The one side enlargement ratio G 21 of the subject M1 is G 21 =
It becomes 2.0408. Signal strength I of subject M1
D21 is I D21 = 0.2401 (I E / S 0 ). Side enlargement factor G 22 of the object M2 is, G 22 = 2.0
000. The signal strength I D12 of the subject M2 is I
D12 = 0.2500 becomes (I E / S 0). Subject M
The one-sided enlargement ratio G 23 of 3 is G 23 = 1.9608. The signal intensity I D13 of the subject M3 is I D13 = 0.2.
601 a (I E / S 0).
【0074】<条件3>の画像について、まず、条件2
での被写体M2の一辺拡大率G22に対する条件3での
被写体M2の一辺拡大率G32の補正係数をk32とす
ると、補正係数k32と一辺拡大率との関係は、次式で
示される。
(G32*k32)/G22=1Regarding the image of <condition 3>, first, the condition 2
Assuming that the correction coefficient of the one side enlargement ratio G 32 of the subject M2 under the condition 3 with respect to the one side enlargement ratio G 22 of the subject M2 is k 32 , the relationship between the correction coefficient k 32 and the one side enlargement ratio is expressed by the following equation. . (G 32 * k 32 ) / G 22 = 1
【0075】よって、条件2での被写体M2の一辺拡大
率に対する条件3での被写体M2の一辺拡大率の補正係
数k32は、
k32=G22/G32=2.0000/1.3333
=1.5000
となる。Therefore, the correction coefficient k 32 of the one side enlargement ratio of the subject M2 under the condition 3 with respect to the one side enlargement ratio of the subject M2 under the condition 2 is k 32 = G 22 / G 32 = 2.0000 / 1.3333
= 1.5000.
【0076】従って、条件3の被写体M1、M2、M3
の各々の一辺拡大率を、1.5000倍する。Therefore, the subjects M1, M2, M3 of condition 3
Each side expansion factor is multiplied by 1.5000.
【0077】被写体M1の補正後の一辺拡大率G31’
は、
G31’=1.3514* 1.5000=2.027
1
となる。One-side magnification G 31 ' after correction of the subject M1
Is G 31 ' = 1.3514 * 1.5000 = 2.027
It becomes 1.
【0078】X線撮像手段6の受光面22が受ける信号
強度ID31、被写体M1の面積拡大率GS31は、補
正後信号強度ID31’、被写体M1の補正後面積拡大
率GSD31’に夫々置き換えられる。よって、(6)
式より、
ID31’=IE/(S0*GS31’)
=IE/{S0*(G31’)2}
=IE/(S0*4.1091)
=0.2434(IE/S0)
となる。The signal intensity I D31 received by the light-receiving surface 22 of the X-ray imaging means 6 and the area enlargement ratio GS 31 of the subject M1 are respectively the corrected signal intensity I D31 ' and the corrected area enlargement ratio GS D31' of the subject M1. Will be replaced. Therefore, (6)
From the formula, I D31 ′ = I E / (S 0 * GS 31 ′ ) = I E / {S 0 * (G 31 ′ ) 2 } = I E / (S 0 * 4.1091) = 0.2434 ( I E / S 0 ).
【0079】被写体M2の補正後の一辺拡大率G32’
は、
G32’=1.3333* 1.5000=2.000
0
となる。One-side magnification G 32 ' after correction of subject M2
Is G 32 ' = 1.3333 * 1.5000 = 2.000
It becomes 0.
【0080】X線撮像手段6の受光面22が受ける信号
強度ID32、被写体M2の面積拡大率GS32は、被
写体M2の補正後面積拡大率GS32’に置き換えられ
る。よって、(3)式より、
ID32’=IE/(S0*GS32’)
=IE/{S0*(G32’)2}
=IE/(S0*4.0000)
=0.2500(IE/S0)
となる。The signal intensity I D32 received by the light receiving surface 22 of the X-ray imaging means 6 and the area expansion rate GS 32 of the subject M2 are replaced with the corrected area expansion rate GS 32 ' of the subject M2. Therefore, according to the equation (3), I D32 ' = I E / (S 0 * GS 32' ) = I E / {S 0 * (G 32 ' ) 2 } = I E / (S 0 * 4.00) = 0.2500 a (I E / S 0).
【0081】被写体M3の補正後の一辺拡大率G33’
は、
G33’=1.3158* 1.5000=1.973
7
となる。One-side enlargement ratio G 33 ' after correction of the subject M3
Is G 33 ′ = 1.3158 * 1.5000 = 1.973
7
【0082】X線撮像手段6の受光面22が受ける信号
強度ID33、被写体M3の面積拡大率GS33は、補
正後信号強度ID33’、被写体M3の補正後面積拡大
率GS33’に夫々置き換えられる。よって、(9)式
より、
ID33’=IE/(S0*GS33’)
=IE/{S0*(G33’)2}
=IE/(S0*3.8955)
=0.2567(IE/S0)
となる。The signal intensity I D33 received by the light receiving surface 22 of the X-ray imaging means 6 and the area enlargement ratio GS 33 of the subject M3 are respectively the corrected signal intensity I D33 ' and the corrected area enlargement ratio GS 33' of the subject M3. Will be replaced. Therefore, from the formula (9), I D33 ′ = I E / (S 0 * GS 33 ′ ) = I E / {S 0 * (G 33 ′ ) 2 } = I E / (S 0 * 3.8955) = 0.2567 (I E / S 0 ).
【0083】以上の結果をまとめると、図7の様にな
る。The above results are summarized as shown in FIG.
【0084】次いで、図8〜12に基づいて説明する。Next, description will be made with reference to FIGS.
【0085】条件2の被写体M2を基準として条件2の
画像に、補正された条件1の画像および補正された条件
3の画像を重ね合わせると、図8、図9、図10、図1
1に示す如く、被写体M1はID11’、ID21’、I
D31’の異なる信号強度が、異なる大きさをもって、
ズレて現れる。When the corrected image of condition 1 and the corrected image of condition 3 are superimposed on the image of condition 2 with the subject M2 of condition 2 as a reference, FIG. 8, FIG. 9, FIG.
As shown in FIG. 1, the subject M1 is I D11 ', I D21', I
Different signal strengths of D31 ' have different magnitudes,
Appears to shift.
【0086】同様に、被写体M3もID13’、I
D23’、ID33’の異なる信号強度が、異なる大きさ
をもって、ズレて現れる。被写体M2については、I
D12’、ID22’、ID32’が同じ大きさの信号強
度をもって重なって現れる。Similarly, the subject M3 also has ID 13 ', I
The different signal intensities of D23 'and I D33' appear to be different in magnitude. For subject M2, I
D12 ', I D22', and I D32 ' appear in an overlapping manner with the same signal strength.
【0087】これは、求める被写体画像上の任意の部分
はズレることなく黒化度成分が大きくなり、一方、それ
以外の部分は重なりがズレて黒化度成分が小さくなるこ
とを示している。This shows that the blackening degree component is large without any shift in the desired image on the subject image, while the blackening degree component is small in the other portions, and the blackening degree component is small.
【0088】ここでは、三枚の撮像画をもとに補正を掛
け、重ね合わせた例を示したが、元となる撮像画の枚数
を多くし同様の作業をすることによって、ズレずに重な
る像はさらに黒化度を増し、求める被写体とそれ以外の
被写体との境界(求める被写体の輪郭)はコントラスト
が強く明確になって来る。さらに、マッハ効果によりコ
ントラストが強くなった輪郭は視覚に強く訴えることに
なり、断層像の認識を容易にする。(図12参照)Here, an example is shown in which correction is performed based on three picked-up images and the images are superimposed, but by increasing the number of original picked-up images and performing the same work, they are not overlapped. The image further increases the degree of blackening, and the boundary between the desired subject and the other subjects (outline of the desired subject) has a strong contrast and becomes clear. Further, the contour having the increased contrast due to the Mach effect is strongly appealing to the eyes and facilitates the recognition of the tomographic image. (See Figure 12)
【0089】また、上述した本願発明における補正後一
辺拡大率と、特開平7−23939号公報の発明での補
正後一辺拡大率を比較することにより、本願発明の優位
性をより明確にする。Further, by comparing the corrected one-side enlargement ratio in the invention of the present application with the corrected one-side enlargement ratio of the invention of Japanese Patent Laid-Open No. 7-23939, the superiority of the present invention is clarified.
【0090】特開平7−23939号公報の発明に関し
ては、図20に示す如く、本願発明と同様に、実状に則
したA,B,Lの各距離値を設定し、被写体MからX線
撮像手段202の受光面206までの距離を一定に保っ
たまま、X線源204から被写体M1、M2、M3まで
の距離を変化させ、一辺拡大率、面積拡大率及びX線撮
像手段202の受光面206が受ける信号強度の値を求
める。With respect to the invention of Japanese Patent Laid-Open No. 7-23939, as shown in FIG. 20, as in the present invention, the distance values of A, B, and L are set according to the actual condition, and X-ray imaging is performed from the subject M. While keeping the distance to the light receiving surface 206 of the means 202 constant, the distance from the X-ray source 204 to the subjects M1, M2, and M3 is changed, and the one side enlargement ratio, the area enlargement ratio, and the light receiving surface of the X-ray imaging means 202 are changed. The value of the signal strength received by 206 is determined.
【0091】まず、被写体M1、M2、M3の面積をS
0(S0≠0)、B=20mm(一定)とし、L=10
mmとし、被写体M1、M2、M3に照射される信号強
度をIEとし、条件1をA=250mm、条件2をA=
500mm、条件3をA=750mmとして、一辺拡大
率、面積拡大率及び受光面が受ける信号強度を、本願発
明と同様に計算し、条件2の被写体M2を求める断層面
としたときの画像再構築の計算も同様に行った。First, the areas of the subjects M1, M2 and M3 are S
0 (S 0 ≠ 0), B = 20 mm (constant), L = 10
mm, the intensity of the signal emitted to the subjects M1, M2, and M3 is I E , condition 1 is A = 250 mm, condition 2 is A =
Image reconstruction when a one-side expansion rate, an area expansion rate, and a signal intensity received by the light receiving surface are calculated in the same manner as in the present invention, assuming that the subject M2 is 500 mm and the condition 3 is A = 750 mm, and the subject M2 of the condition 2 is obtained. Was calculated in the same manner.
【0092】以上の特開平7−23939号公報の発明
の結果をまとめると、図21、22の様になる。The results of the invention of Japanese Patent Laid-Open No. 7-23939 described above can be summarized as shown in FIGS.
【0093】以上の補正後一辺拡大率の結果から、本願
発明の図7及び特開平7−23939号公報の発明の図
22の補正後一辺拡大率比較を、図13に示す。FIG. 13 shows a comparison of the corrected one side enlargement ratios of FIG. 7 of the present invention and FIG. 22 of the invention of Japanese Patent Application Laid-Open No. 7-23939 from the above results of the corrected one side enlargement ratios.
【0094】この図13においては、縦軸に補正後一辺
拡大率、横軸にX線源から被写体Mまでの距離を示す。In FIG. 13, the vertical axis shows the corrected one-side enlargement ratio, and the horizontal axis shows the distance from the X-ray source to the subject M.
【0095】被写体M1の本願発明の補正後一辺拡大率
は、条件1では2.0834、条件2では2.040
8、条件3では2.0271であり、条件1と条件2と
の差は0.0426、条件2と条件3との差は0.01
37となる。同様に、被写体M1の特開平7−2393
9号公報の発明の補正後一辺拡大率は、条件1では1.
0834、条件2では1.0612、条件3では1.0
540であり、条件1と条件2との差は0.0222、
条件2と条件3との差は0.0072となる。被写体M
3も同様に、被写体M3の本願発明の補正後一辺拡大率
は、条件1では1.9231、条件2では1.960
8、条件3では1.9737であり、条件1と条件2と
の差は0.0377、条件2と条件3との差は0.01
29となる。被写体M3の特開平7−23939号公報
の発明の補正後一辺拡大率は条件1では1.0001、
条件2では1.0196、条件3では1.0264であ
り、条件1と条件2との差は0.0195、条件2と条
件3との差は0.0068となる。The corrected one-side enlargement ratio of the subject M1 according to the present invention is 2.0834 for condition 1 and 2.040 for condition 2.
8, condition 3 is 2.0271, the difference between condition 1 and condition 2 is 0.0426, and the difference between condition 2 and condition 3 is 0.01
37. Similarly, the subject M1 of Japanese Patent Laid-Open No. 7-2393
The corrected one-side enlargement ratio of the invention of Japanese Patent No. 9 is 1.
0834, 1.0612 in condition 2, 1.0 in condition 3
540, the difference between condition 1 and condition 2 is 0.0222,
The difference between Condition 2 and Condition 3 is 0.0072. Subject M
Similarly, the corrected one-side enlargement ratio of the subject M3 according to the present invention is 1.9231 in condition 1 and 1.960 in condition 2.
8, condition 3 is 1.9737, the difference between condition 1 and condition 2 is 0.0377, and the difference between condition 2 and condition 3 is 0.01
29. The corrected one-side enlargement ratio of the subject M3 according to the invention of Japanese Patent Application Laid-Open No. 7-23939 is 1.0001 under condition 1.
The condition 2 is 1.0196, the condition 3 is 1.0264, the difference between the condition 1 and the condition 2 is 0.0195, and the difference between the condition 2 and the condition 3 is 0.0068.
【0096】ここで、本願発明での補正後一辺拡大率の
ズレの差は、特開平7−23939号公報の発明の補正
後一辺拡大率のズレの差よりも大きく、この一辺拡大率
のズレの差が大きいほど求める断層面以外の断層像のズ
レが大きく現れ、黒化度成分が小さくなる。被写体M2
に関しては、条件2の被写体2に対して補正してあるた
め、条件1、条件2、条件3の各々の被写体M2補正後
一辺拡大率はズレることがない。このため、求める被写
体M2の断層面はズレることなく黒化度成分が大きくな
り、求める被写体の断層面とそれ以外の被写体の断層面
との境界はコントラストが強く明確になってくる。Here, the difference between the corrected one-side enlargement ratios in the present invention is larger than the difference between the corrected one-side enlargement ratios in the invention of Japanese Patent Laid-Open No. 7-23939, and the difference between the one-side enlargement ratios. The larger the difference between, the larger the deviation of the tomographic image other than the desired tomographic plane appears, and the smaller the blackening component. Subject M2
With respect to the above, since the subject 2 of condition 2 is corrected, the one-side enlargement ratio after the subject M2 correction of each of condition 1, condition 2, and condition 3 does not deviate. For this reason, the tomographic plane of the subject M2 to be obtained has a large blackening component without deviation, and the boundary between the tomographic plane of the subject to be obtained and the tomographic planes of the other subjects becomes strong and clear.
【0097】即ち、本願発明は、特開平7−23939
号公報の発明よりも、補正後一辺拡大率及び面積拡大率
の差が大きくなるため、よりマッハ効果が強調され、求
める被写体Mの断層面とそれ以外の被写体の断層面との
境界はコントラストが強く明確に現れる。なお、図2
1、22には、参考のために信号強度も明記した。That is, the present invention is disclosed in JP-A-7-23939.
Since the difference between the corrected one-side enlargement ratio and the area enlargement ratio becomes larger than that in the invention of the publication, the Mach effect is further emphasized, and the boundary between the tomographic plane of the subject M to be obtained and the tomographic plane of the other subjects has a higher contrast. Appear strongly and clearly. Note that FIG.
For reference, signal strengths are also specified in Nos. 1 and 22.
【0098】次に、被写体Mのズレの方向および大きさ
について説明する。Next, the direction and size of the displacement of the subject M will be described.
【0099】図14は被写体MとX線源4との距離がA
からA+xに移動したときの、求める被写体Mの画像に
対し、それ以外の画像がズレて重なる位置関係の計算例
を示す。このとき、xは移動距離を示している。In FIG. 14, the distance between the subject M and the X-ray source 4 is A.
An example of the calculation of the positional relationship in which the image of the subject M to be obtained when moving from A to A + x is shifted and overlapped with other images will be shown. At this time, x indicates the moving distance.
【0100】図15は被写体M1、M2、M3の位置関
係を示す座標図である。まず、被写体M2を0とする
と、被写体M1は被写体M2からX軸方向に−L、Y軸
方向にPの位置に位置する。次に、被写体M3は被写体
M2からX軸方向にL、Y軸方向に−Pの位置に位置す
る。この被写体M1、M2、M3の座標関係は変化しな
いものとする。FIG. 15 is a coordinate diagram showing the positional relationship among the subjects M1, M2, M3. First, assuming that the subject M2 is 0, the subject M1 is located at a position -L in the X-axis direction and P in the Y-axis direction from the subject M2. Next, the subject M3 is located at a position L from the subject M2 in the X-axis direction and -P in the Y-axis direction. It is assumed that the coordinate relationship between the subjects M1, M2, M3 does not change.
【0101】被写体M1a、M2a、M3aを基準面と
し、被写体M1a、M2a、M3aが距離xだけX線撮
像手段6の受光面22側に移動した被写体を被写体M1
b、M2b、M3bとし、基準面の被写体M2aを求め
る被写体とする。The subject M1a, M2a, M3a is used as a reference plane, and the subject M1a, M2a, M3a moved to the light receiving surface 22 side of the X-ray imaging means 6 by the distance x is the subject M1.
b, M2b, and M3b, and the subject M2a on the reference plane is the subject to be obtained.
【0102】次に、X線源4から受光面22に垂直方向
に引いた軸をX軸とし、X軸を基準に被写体M1aのX
線撮像手段6の受光面22での断層像の距離をQ1aで
示し、被写体M1bのX線撮像手段6の受光面22での
断層像の距離をQ1bで示す。また、同様に、被写体M
3aのX線撮像手段6の受光面22での断層像の距離を
−Q3aで示し、被写体M3bの受光面22での断層像
の距離を−Q3bで示す。Next, the axis drawn from the X-ray source 4 in the direction perpendicular to the light-receiving surface 22 is taken as the X-axis, and the X-axis is used as a reference for the X-axis of the subject M1a.
The distance of the tomographic image on the light receiving surface 22 of the X-ray imaging unit 6 is indicated by Q1a, and the distance of the tomographic image of the subject M1b on the light receiving surface 22 of the X-ray imaging unit 6 is indicated by Q1b. Similarly, the subject M
The distance of the tomographic image on the light receiving surface 22 of the X-ray imaging unit 6 of 3a is indicated by -Q3a, and the distance of the tomographic image on the light receiving surface 22 of the subject M3b is indicated by -Q3b.
【0103】まず、被写体M1aのX線撮像手段6の受
光面22でのQ1aの長さは、次のように示される。
Q1a={p*(A+B)}/(A−L)……(11)First, the length of Q1a on the light-receiving surface 22 of the X-ray imaging means 6 of the subject M1a is shown as follows. Q1a = {p * (A + B)} / (AL) …… (11)
【0104】被写体M1bのX線撮像手段6の受光面2
2でのQ1bの長さは、次のように示される。
Q1b={p*(A+B)}/(A+x−L)……(12)Light receiving surface 2 of the X-ray imaging means 6 of the subject M1b
The length of Q1b at 2 is shown as: Q1b = {p * (A + B)} / (A + x−L) (12)
【0105】被写体M1aの断層像の一辺拡大率に対す
る被写体M1bの断層像の一辺拡大率の補正係数をk
Q1とおくと、(Q1b*kQ1)/Q1a=1より、
kQ1=Q1a/Q1b……(13)
となる。The correction coefficient of the one side magnification of the tomographic image of the subject M1b with respect to the one side magnification of the tomographic image of the subject M1a is k.
When put to the Q1, the from (Q1b * k Q1) / Q1a = 1, k Q1 = Q1a / Q1b ...... (13).
【0106】この(13)式に(11)、(12)の式
を代入すると、
kQ1=[{p*(A+B)}/(A−L)]/[{p*(A+B)}/(A+x
−L)]=(A+x−L)/(A−L)
={(A−L)/(A−L)}+{x/(A−L)}
=1+{x/(A−L)}
となる。Substituting the expressions (11) and (12) into the expression (13), k Q1 = [{p * (A + B)} / (AL)] / [{p * (A + B)} / (A + x−L)] = (A + x−L) / (A−L) = {(A−L) / (A−L)} + {x / (A−L)} = 1+ {x / (A−) L)}.
【0107】ここで、(13)式はQ1a=Q1b*k
Q1となり、kQ1=1+{x/(A−L)}を代入する
と、
Q1a=Q1b* [1+{x/(A−L)}]
Q1a=Q1b+{x/(A−L)}*Q1b
Q1a−Q1b={x/(A−L)}*Q1b
となる。Here, the equation (13) is Q1a = Q1b * k
It becomes Q1 , and when k Q1 = 1 + {x / (AL)} is substituted, Q1a = Q1b * [1+ {x / (AL)}] Q1a = Q1b + {x / (AL)} * Q1b Q1a-Q1b = {x / (AL)} * Q1b.
【0108】即ち、x=0の時、被写体M1aと被写体
M1bの撮影像は重なり合う。xが大きくなると、Q1
bが小さくなり、被写体M1bの撮影像は被写体M2a
の撮影像の方向へと移動していく。That is, when x = 0, the photographed images of the subject M1a and the subject M1b overlap. When x becomes large, Q1
b becomes smaller, and the captured image of the subject M1b becomes the subject M2a.
It moves in the direction of the captured image of.
【0109】同様にして、被写体M3aの受光面22で
の−Q3aの長さは、次のように示される。
−Q3a={−p*(A+B)}/(A+L)……(14)Similarly, the length of -Q3a on the light receiving surface 22 of the subject M3a is shown as follows. -Q3a = {-p * (A + B)} / (A + L) (14)
【0110】被写体M3bの受光面22での−Q3bの
長さは、次のように示される。
−Q3b={−p*(A+B)}/(A+x+L)……(15)The length of -Q3b on the light receiving surface 22 of the subject M3b is shown as follows. -Q3b = {-p * (A + B)} / (A + x + L) (15)
【0111】被写体M3aの撮影像の一辺拡大率に対す
る被写体M3bの撮影像の一辺拡大率の補正係数をk
Q3とおくと、(−Q3b*kQ3)/−Q3a=1より
kQ3=−Q3a/−Q3b……(16)
となる。The correction coefficient of the one side enlargement ratio of the taken image of the subject M3b to the one side enlargement ratio of the taken image of the subject M3a is k.
When put to the Q3, the Q3a = 1 than k Q3 = -Q3a / -Q3b ...... ( 16) - (- Q3b * k Q3) /.
【0112】この(16)式に(14)、(15)の式
を代入すると、
kQ3=[{−p*(A+B)}/(A+L)]/[{−p*(A+B)}/(A+
x+L)]=(A+x+L)/(A+L)
={(A+L)/(A+L)}+{x/(A+L)}
=1+{x/(A+L)}
となる。Substituting the equations (14) and (15) into the equation (16), k Q3 = [{-p * (A + B)} / (A + L)] / [{-p * (A + B)} / (A + x + L)] = (A + x + L) / (A + L) = {(A + L) / (A + L)} + {x / (A + L)} = 1+ {x / (A + L)}.
【0113】ここで、(16)式は−Q3a=−Q3b
*kQ3となり、kQ1=1+{x/(A+L)}を代入
すると、
−Q3a=−Q3b* [1+{x/(A+L)}]
Q3a=Q3b+{x/(A+L)}*Q3b
Q3a−Q3b={x/(A+L)}*Q3b
となる。Here, the equation (16) is -Q3a = -Q3b
* K Q3 , and substituting k Q1 = 1 + {x / (A + L)}, -Q3a = -Q3b * [1+ {x / (A + L)}] Q3a = Q3b + {x / (A + L)} * Q3b Q3a- Q3b = {x / (A + L)} * Q3b.
【0114】即ち、x=0の時、被写体M1aと被写体
M1bの撮影像は重なり合う。xが大きくなると、Q3
bが小さくなり、被写体M3bの撮影像は被写体M2a
の撮影像の方向へと移動していく。That is, when x = 0, the photographed images of the subject M1a and the subject M1b overlap. When x becomes large, Q3
b becomes smaller, and the captured image of the subject M3b becomes the subject M2a.
It moves in the direction of the captured image of.
【0115】被写体M1a、M2a、M3aの基準面の
撮影像に対し、X線源4と被写体Mの距離をxだけ移動
した被写体Mの撮影像を重ね合わせていくと、求める被
写体M2a以外の撮影像は同じ位置に重なるのではな
く、被写体M2a方向にズレて重なることになり、より
ボケ像となる(図16参照)。When the captured images of the subject M1a, M2a, M3a are superposed on the captured images of the reference plane of the subject M1a, M2a, M3a by moving the distance between the X-ray source 4 and the subject M by x, the captured images other than the desired subject M2a The images do not overlap at the same position but shift in the direction of the subject M2a and overlap, resulting in a more blurred image (see FIG. 16).
【0116】以上のことから、求める被写体撮影像に、
それ以外の被写体撮影像を重ね合わせることにより、各
撮影像のズレは求める被写体M2aの撮影像に近付いて
いく。また、ズレの大きさは、被写体M3よりも被写体
M1の方が大きくなる。これは、被写体M1の方が被写
体3よりも一辺拡大率が大きいためである。From the above, in the subject photographed image,
By superimposing the other photographic images of the subject, the deviation of each photographic image approaches the photographic image of the desired subject M2a. Further, the magnitude of the deviation is larger in the subject M1 than in the subject M3. This is because the subject M1 has a larger side expansion ratio than the subject 3.
【0117】この結果、この実施例においては、拡大率
を利用して所望部位を撮影する装置を提供し、管球焦点
と検出部とを直線運動させ、その運動と共にX線照射を
し、被写体をある時間毎にフレーム画像に取り込みなが
ら撮影し、被写体が固定されているので、ある基準点を
予め決めておけば、それに合わせて拡大率を決定し、そ
の拡大率に合わせて画像を生成することにより、所望部
位のみ抽出することができる。また、縦、横、斜め方向
に直線運動させれば、所望部位の様々な角度を撮影する
ことができる。As a result, in this embodiment, an apparatus for photographing a desired portion by utilizing the magnification is provided, and the tube focus and the detector are linearly moved, and X-ray irradiation is performed together with the movement, and the object is photographed. Since the subject is fixed by capturing while capturing in the frame image every certain time, if a certain reference point is determined in advance, the enlargement ratio is determined accordingly, and the image is generated according to the enlargement ratio. As a result, only the desired part can be extracted. In addition, by performing linear movements in the vertical, horizontal, and diagonal directions, it is possible to capture various angles of a desired portion.
【0118】これにより、各フレーム毎の画像を得られ
ることで、一回の撮影にて、多くのスライス画像を提供
することができ、より正確な臨床情報を得ることがで
き、被爆線量・撮影時間を減少させ、また、直線運動な
ので、装置を簡単にすることができる。As a result, since images for each frame can be obtained, many slice images can be provided in one shot, more accurate clinical information can be obtained, and radiation dose and radiographing can be performed. The time is reduced and the linear motion allows the device to be simplified.
【0119】つまり、本願発明によれば、一辺拡大率及
び面積拡大率の変化を大きく得ることが可能となり、任
意の被写体画像以外の画像に補正係数の逆数を掛け、こ
れを被写体Mの画像に重ね合わせることにより、これま
で困難であった、口腔内領域の撮影を一度の位置付けで
行うことが可能となり、また、必要に応じて任意の断層
像を再構築することが可能となり、さらに、X線断層撮
影装置2の小型化が可能となるので、廉価に製作可能な
り、口腔内領域のみならずや頭部の断層撮影でのニーズ
に応えることが可能となる。That is, according to the present invention, it is possible to obtain a large change in the one-sided enlargement ratio and the area enlargement ratio, and an image other than an arbitrary subject image is multiplied by the reciprocal of the correction coefficient to obtain an image of the subject M. By superimposing them, it is possible to perform imaging of the intraoral region with a single positioning, which has been difficult until now, and it is possible to reconstruct an arbitrary tomographic image as necessary. Since the line tomography apparatus 2 can be miniaturized, it can be manufactured at low cost, and it is possible to meet the needs not only in the oral region but also in the tomography of the head.
【0120】[0120]
【発明の効果】以上詳細な説明から明らかなようにこの
発明によれば、被写体にX線を発生するX線源と被写体
を通過したX線を検出するX線撮像手段とを、被写体を
間にして相互に対向し、且つ、X線源とX線撮像手段と
の距離を一定に設定し、X線撮影構成体を直線移動させ
ながらX線照射を行い、任意の時間毎に被写体の撮影像
をX線源撮像手段で取り込みながらX線撮影を行い、こ
のとき、被写体が予め固定されているので、ある基準点
を予め設定すれば、その基準点に合わせて撮影像の拡大
率は、各々の位置により決定され、取り込まれた複数枚
の撮影像を拡大又は縮小し、その撮影像を重ね合わせて
合成することにより、所望部位の断層面画像を容易に生
成し得る。As is apparent from the above detailed description, according to the present invention, an X-ray source for generating X-rays on an object and an X-ray imaging means for detecting X-rays passing through the object are arranged between the objects. And the X-ray source and the X-ray imaging means are set to a constant distance from each other, and X-ray irradiation is performed while linearly moving the X-ray imaging component, and an object is imaged at arbitrary time intervals. X-ray imaging is performed while the image is captured by the X-ray source imaging means. At this time, since the subject is fixed in advance, if a certain reference point is set in advance, the magnifying power of the captured image according to the reference point will be It is possible to easily generate a tomographic image of a desired portion by enlarging or reducing a plurality of captured images that are determined by the respective positions, and superimposing the captured images and combining them.
【図1】X線撮影構成体の直線移動状態を示す正面図で
ある。FIG. 1 is a front view showing a linear movement state of an X-ray imaging structure.
【図2】X線源から被写体までの距離と一辺拡大率との
関係を示す図である。FIG. 2 is a diagram showing a relationship between a distance from an X-ray source to a subject and a side enlargement ratio.
【図3】単一の被写体の撮影を示す正面図である。FIG. 3 is a front view showing shooting of a single subject.
【図4】複数の被写体の撮影を示す正面図である。FIG. 4 is a front view showing shooting of a plurality of subjects.
【図5】複数の被写体の各条件での撮影を示す正面図で
ある。FIG. 5 is a front view showing photographing of a plurality of subjects under each condition.
【図6】複数の被写体の各条件での補正前の拡大率及び
信号強度を示す図である。FIG. 6 is a diagram showing an enlargement ratio and a signal strength before correction under a plurality of conditions for a plurality of subjects.
【図7】複数の被写体の各条件での補正後の拡大率及び
信号強度を示す図である。FIG. 7 is a diagram showing a magnification rate and a signal intensity after correction of a plurality of subjects under respective conditions.
【図8】撮影像を縮小したときの撮影を示す図である。FIG. 8 is a diagram illustrating shooting when a captured image is reduced.
【図9】撮影像を等倍したときの撮影を示す図である。FIG. 9 is a diagram showing photographing when a photographed image is magnified.
【図10】撮影像を拡大したときの撮影を示す図であ
る。FIG. 10 is a diagram showing photographing when a photographed image is enlarged.
【図11】撮影像を合成したときを示す図である。FIG. 11 is a diagram showing a case where captured images are combined.
【図12】信号強度を示す図である。FIG. 12 is a diagram showing signal strength.
【図13】補正後の一辺拡大率を示す図である。FIG. 13 is a diagram showing a corrected one-side enlargement ratio.
【図14】被写体とX線源との距離が移動したときの図
である。FIG. 14 is a diagram when the distance between the subject and the X-ray source has moved.
【図15】各被写体の位置関係を示す座標図である。FIG. 15 is a coordinate diagram showing a positional relationship between subjects.
【図16】被写体のボケ像を示す図である。FIG. 16 is a diagram showing a blurred image of a subject.
【図17】実施例において撮影像の生成の流れを示す図
である。FIG. 17 is a diagram showing a flow of generation of a captured image in the embodiment.
【図18】X線断層撮像装置のシステム構成図である。FIG. 18 is a system configuration diagram of an X-ray tomographic imaging apparatus.
【図19】従来においてX線源を移動させた正面図であ
る。FIG. 19 is a front view showing a conventional X-ray source moved.
【図20】従来において複数の被写体の各条件での撮影
を示す正面図である。FIG. 20 is a front view showing conventional photography of a plurality of subjects under each condition.
【図21】従来において複数の被写体の各条件での補正
前の拡大率及び信号強度を示す図である。FIG. 21 is a diagram showing an enlargement ratio and a signal strength before correction in each condition of a plurality of subjects in the related art.
【図22】従来において複数の被写体の各条件での補正
後の拡大率及び信号強度を示す図である。FIG. 22 is a diagram showing a magnification rate and a signal intensity after correction in the related art under a plurality of conditions under respective conditions.
【符号の説明】 2 X線断層撮影装置 4 X線源 6 X線撮像手段 6A 撮影画像部 8 X線撮影構成体 10 直線移動駆動手段 12 移動計測手段 14 撮影影像制御手段 16 拡大率補正手段 18 撮影像合成手段 20 制御装置 22 受光面[Explanation of symbols] 2 X-ray tomography equipment 4 X-ray source 6 X-ray imaging means 6A photographed image section 8 X-ray imaging structure 10 Linear movement drive means 12 Movement measuring means 14 Photographing image control means 16 Enlargement factor correction means 18 Photographed image synthesizing means 20 Control device 22 Light receiving surface
Claims (6)
写体を通過したX線を検出するX線撮像手段とが備えら
れたX線撮影構成体を設け、前記被写体を間にして前記
X線源と前記X線撮像手段とを一定距離に相互に対向し
て前記X線撮影構成体を直線移動させる直線移動駆動手
段を設け、前記X線撮影構成体の直線移動距離を計測す
る移動計測手段を設け、前記X線撮像手段には撮影像を
画く撮影画像部を設け、この撮影画像部での撮影像を制
御する撮影像制御手段を設け、前記撮影画像部での撮影
像の拡大率補正を行う拡大率補正手段を設け、この拡大
率補正手段で補正された撮影像を重ね合わせて合成する
撮影像合成手段を設けたことを特徴とする直線運動型X
線断層撮影装置。1. An X-ray imaging structure provided with an X-ray source for generating X-rays to an object and X-ray imaging means for detecting X-rays passing through the object, the object being interposed between the X-ray imaging structure. A linear movement driving unit that linearly moves the X-ray imaging structure is provided so that the X-ray source and the X-ray imaging unit face each other at a constant distance, and movement for measuring the linear movement distance of the X-ray imaging structure. A measuring means is provided, a photographed image portion for drawing a photographed image is provided in the X-ray image pickup means, and a photographed image control means for controlling the photographed image in the photographed image portion is provided to enlarge the photographed image in the photographed image portion. A linear motion type X characterized in that a magnifying power correcting means for correcting the magnifying power is provided, and a photographed image synthesizing means for superimposing and synthesizing the photographed images corrected by the magnifying power correcting means is provided.
Line tomography device.
ジセンサとしての画像センサーからなることを特徴とす
る請求項1に記載の直線運動型X線断層撮影装置。2. The linear motion X-ray tomography apparatus according to claim 1, wherein the X-ray imaging unit is an image sensor as a two-dimensional X-ray image sensor.
層面位置に目印となる不透過性のアダプタが設けられた
ことを特徴とする請求項1に記載の直線運動型X線断層
撮影装置。3. The linear motion type X-ray tomography apparatus according to claim 1, wherein the movement measuring means is provided with an impermeable adapter which serves as a mark at a position of a tomographic plane of the subject. .
コーダ、反射型位置計測装置からなることを特徴とする
請求項1に記載の直線型X線断層撮影装置。4. The linear X-ray tomography apparatus according to claim 1, wherein the movement measuring unit includes a PSD element, an encoder, and a reflection-type position measuring apparatus.
撮影像の一辺拡大率をGとし、この位置に重ね合わされ
る複数の撮影像の拡大率をB1、B2、B3…とすると
き、補正係数をB1/G、B2/G、B3/G…とし、
前記撮影像合成手段は、これらの補正された撮影像を重
ね合わせる機能を有することを特徴とする請求項1に記
載の直線運動型X線断層撮影装置。5. The magnifying power correction means sets G to be one side magnifying power of a photographed image at an arbitrary position, and B1, B2, B3 ... , Correction coefficients are B1 / G, B2 / G, B3 / G ...
The linear motion X-ray tomography apparatus according to claim 1, wherein the captured image synthesizing unit has a function of superposing these corrected captured images.
連続的に撮影する方式と任意時間毎に撮影する方式とを
備えることを特徴とする請求項1に記載の直線運動型X
線断層撮影装置。6. The captured image portion of the X-ray imaging means is
The linear motion type X according to claim 1, comprising a method of continuously photographing and a method of photographing every arbitrary time.
Line tomography device.
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Cited By (4)
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JP2007312968A (en) * | 2006-05-25 | 2007-12-06 | Yoshida Dental Mfg Co Ltd | Tomographic image generator, tomographic image generating method, and tomographic image generating program |
JP2009254472A (en) * | 2008-04-15 | 2009-11-05 | Yoshida Dental Mfg Co Ltd | X-ray imaging method and device |
JP2010011910A (en) * | 2008-07-01 | 2010-01-21 | Yoshida Dental Mfg Co Ltd | Digital panoramic imaging apparatus and panoramic image processing program |
US7729468B2 (en) * | 2004-02-27 | 2010-06-01 | Kabushiki Kaisha Toshiba | X-ray tomograph and stereoradioscopic image construction equipment |
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JPH06277205A (en) * | 1993-03-26 | 1994-10-04 | Hamamatsu Photonics Kk | X-ray diagnostic device |
JPH0723939A (en) * | 1993-07-12 | 1995-01-27 | Hitachi Medical Corp | X-ray tomographic device |
JPH08215182A (en) * | 1995-02-09 | 1996-08-27 | Morita Mfg Co Ltd | Medical x-ray photographing device |
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Publication number | Priority date | Publication date | Assignee | Title |
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JP2007312968A (en) * | 2006-05-25 | 2007-12-06 | Yoshida Dental Mfg Co Ltd | Tomographic image generator, tomographic image generating method, and tomographic image generating program |
JP2009254472A (en) * | 2008-04-15 | 2009-11-05 | Yoshida Dental Mfg Co Ltd | X-ray imaging method and device |
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