JPS58118734A - Ct scanner apparatus - Google Patents
Ct scanner apparatusInfo
- Publication number
- JPS58118734A JPS58118734A JP57000254A JP25482A JPS58118734A JP S58118734 A JPS58118734 A JP S58118734A JP 57000254 A JP57000254 A JP 57000254A JP 25482 A JP25482 A JP 25482A JP S58118734 A JPS58118734 A JP S58118734A
- Authority
- JP
- Japan
- Prior art keywords
- computer
- measurement
- transmission data
- scanner
- system control
- 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
- 238000005259 measurement Methods 0.000 claims description 31
- 230000005855 radiation Effects 0.000 claims description 18
- 230000005540 biological transmission Effects 0.000 claims description 16
- 238000000034 method Methods 0.000 description 13
- 238000010586 diagram Methods 0.000 description 7
- 239000000446 fuel Substances 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 5
- 230000005514 two-phase flow Effects 0.000 description 5
- 239000000126 substance Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 2
- 238000013480 data collection Methods 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Analysing Materials By The Use Of Radiation (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
本発明はCTスキャナに係り、特に測定対象中に放射線
吸収率の大きい物質がある場合、または測定対象の密度
分布が変動する場合に、精度の高い測定をするのに好適
なCTスキャナ装置およびその像再構成方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CT scanner, and is particularly useful for highly accurate measurement when there is a substance with a high radiation absorption rate in the measurement object or when the density distribution of the measurement object fluctuates. The present invention relates to a suitable CT scanner device and its image reconstruction method.
従来OCTスキャナは一定の速度で並進運動または回転
運動を行い、1回のスキャンにより断面密度分布を再構
成していた。例としてT−R方式、R−4方式による測
定法を第1図、第2図に示す。Conventionally, an OCT scanner performs translational or rotational motion at a constant speed, and reconstructs the cross-sectional density distribution with one scan. As examples, measurement methods using the TR method and the R-4 method are shown in FIGS. 1 and 2.
従来の装置を用いて直径3cM1のアクリル管内の二相
流を測定する場合、透過放射線強度は大きく変動し、振
幅が大きい所では第3図に示す様に、測定値の最大値は
最小値の2倍程度になる。このような条件下で、例えば
T−R,方式による測定、つまり1画素、1方向照射時
間2m5ecで、1回だけのスキャンにより像を再構成
すると、水・空気密度差の約20係の誤差が生じるっま
た従来の装置を用いて、13WR(8X8)燃料集合体
を測定する場合、第4図の8の経路を持つ透過放射線の
強度は、7の経路の約16万分の1となる。データのノ
イズは放射線強度の平方根に比例するため、8の経路の
透過放射線データのノイズば7の経路の約400倍とな
る。このように従来のCTスキャナ装置およびそのI抜
書構成方法では、測定対象の密度分布が変化する場合、
捷たは測定対象中に放射線吸収率の大きい物質がある場
合に測定種度が悪くなるという欠点があった。When measuring two-phase flow in an acrylic tube with a diameter of 3 cM using a conventional device, the transmitted radiation intensity fluctuates greatly, and in areas where the amplitude is large, the maximum value of the measured value is higher than the minimum value, as shown in Figure 3. It will be about twice as large. Under such conditions, when an image is reconstructed by scanning only once using measurement using the T-R method, that is, one pixel and one direction irradiation time of 2 m5ec, an error of about 20 factors due to the difference in water and air density will occur. When measuring a 13WR (8×8) fuel assembly using conventional equipment, the intensity of the transmitted radiation having path 8 in FIG. 4 is approximately 160,000 times lower than path 7. Since the data noise is proportional to the square root of the radiation intensity, the noise of the transmitted radiation data of the path 8 is about 400 times that of the path 7. In this way, with the conventional CT scanner device and its I-extraction configuration method, when the density distribution of the measurement target changes,
There is a drawback that the measurement accuracy deteriorates when there is a substance with a high radiation absorption rate in the measurement target.
本発明の目的は、測定対象の密度分布が変化する場合ま
たは測だ対象中に放射線吸収率の大きい物質がある場合
でも、精度の高い測定ができるCTスキャナ装酋および
その1像書構戎方法を提供するととKある。An object of the present invention is to provide a CT scanner installation and an image formatting method thereof, which can perform highly accurate measurements even when the density distribution of the measurement object changes or when there is a substance with a high radiation absorption rate in the measurement object. There is K to provide.
従来の人体測定用CTスキャナ装置は、静止物体を測定
対象としていたため、二相流の1虫に断面密度分布が変
動する測定対象の場合、強いアーティファクト(擬画像
)が生じ、測定誤差が大きくなった。また燃料集合体の
測定を行う場合、放射線吸収ポの大きい燃料ビンを透過
した放射線強度は弱く々るため、測定値に含まれるノイ
ズが犬きくなる。本発明は変動する測定対象に対しては
、測定時間、測定回数増加により透過データの時間平均
値が得られるよう、−また放射線吸収率の大きい物質の
ため強度が弱い放射線は、測定時間延長によりカウント
数を増加させ、ノイズが小さくなるようにし、燃料集合
体中の二相流を測定する場合でも高い精度の再構成像が
得られるようにしたものである。Conventional human body measurement CT scanners measure stationary objects, so if the object is a two-phase flow whose cross-sectional density distribution fluctuates, strong artifacts (pseudo-images) will occur, resulting in large measurement errors. became. Furthermore, when measuring fuel assemblies, the intensity of radiation transmitted through a fuel bottle with a large radiation absorption capacity is weak, so the noise contained in the measured values becomes significant. The present invention is designed to obtain a time average value of transmission data by increasing the measurement time and number of measurements for fluctuating measurement targets; The number of counts is increased to reduce noise, and a highly accurate reconstructed image can be obtained even when measuring two-phase flow in a fuel assembly.
以下、本発明の一実施例を第4図、第5図により説明す
る。、第4図に示す様に不実施例では、データ収集部と
コンピュータの間に、誤差判定用プログラムおよび制御
d用プログラムを備えたマイコンを設けこれと架台機構
制御部を連絡させた。具体的にこの市11i卸方法の一
例を第6図により説明する。寸ず同図のaの方向に放射
線源および検出器を並進移動させ、同図の実績で示す透
過データ(g+ (X、θ) =i、n (L /:[
)、ただし1.は放射線源強度、■は透過後の放射線強
度である。)を得る。次に同様にbの方向に並進移動を
行い、破細で示す透過データgt (x、 θ)を得
る。マイコンにおいて1g+g21の最大値ΔIg21
e計算し、収束条件値εと比較する。21g21<εの
場合、次の角度での測定を行う制御信号を架台機構市1
1一部に送り、コンピュータには透過データg(X、θ
)=g2(x、θ)=(g++gt)/2を送る。An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. As shown in FIG. 4, in the non-example, a microcomputer equipped with an error determination program and a control program was provided between the data collection section and the computer, and this was communicated with the gantry mechanism control section. A concrete example of this city 11i wholesale method will be explained with reference to FIG. Translationally move the radiation source and detector in the direction a in the same figure, and obtain the transmission data (g+ (X, θ) = i, n (L /: [
), but 1. is the radiation source intensity, and ■ is the radiation intensity after transmission. ). Next, a translational movement is similarly performed in the direction b to obtain transmission data gt (x, θ) shown in fragments. Maximum value ΔIg21 of 1g+g21 in microcontroller
e is calculated and compared with the convergence condition value ε. If 21g21<ε, the control signal for measuring at the next angle is sent to the frame mechanism city 1.
1, and the computer receives transparent data g(X, θ
)=g2(x, θ)=(g++gt)/2 is sent.
21g21>εの、1合、同じ角度での測定を行う信号
を制御部に送る。If 21g21>ε, a signal is sent to the control unit to perform measurement at the same angle.
このようにして得られた透過データをg、(X、θ)と
する、、g s ” (2gt +g+)/ 3を計算
し、Δ1gsl=1gt−正、I とεを比較し、判定
を行う。Let the transmission data obtained in this way be g, (X, θ), calculate g s '' (2gt + g+) / 3, Δ1gsl = 1gt - positive, compare I and ε, and make a judgment. .
以上の手111自をΔIL1〈εとなるまで繰り返す。The above steps 111 are repeated until ΔIL1<ε.
像再構成はg (X、θ )ンれを用いて行う。従来の
方法により二相流を測定した*甘、再構成画像に約20
係の誤差が生じたのに対し、本実施例によればε=8壬
とすること+によりこの誤差を2チ以下にすることがで
きる。透過データの誤差より再構成画像の誤差が小さく
なるのは、像再構成の際透過データは加算され、データ
の誤差が相殺されるためである。Image reconstruction is performed using g (X, θ). The two-phase flow was measured by conventional methods.
However, according to this embodiment, by setting ε=8 mm, this error can be reduced to 2 mm or less. The reason why the error in the reconstructed image is smaller than the error in the transmission data is because the transmission data is added during image reconstruction, and the data errors are canceled out.
次に本発明の他の制御方法例を、第7図を用いて説明す
る。同図は横軸に1ビ一ム照射時間を、縦軸にこの1ビ
一ム照射時間で透過データを平均したイ偵をとったグラ
フである。図に示すように透過データの時間平均値は照
射時間の増大とともに一定値に収束する。マイコン、1
1において、この一定値が得られたことを確認し、次の
点での測定を行う。コンピュータではこの一定値を用い
て像を再構成する。本実施列によれば、変動の小さい透
過データは短い時間で測定し、変動の大きいものだけを
長い時間で測定できるため、前述の実梅タリより短い時
間で同じ精度が得られる。Next, another example of the control method of the present invention will be explained using FIG. 7. In this figure, the horizontal axis is the irradiation time for one beam, and the vertical axis is the average transmission data over the irradiation time for one beam. As shown in the figure, the time average value of the transmission data converges to a constant value as the irradiation time increases. Microcomputer, 1
1, confirm that this constant value has been obtained, and then perform measurements at the following points. The computer uses this constant value to reconstruct the image. According to this implementation, transmission data with small fluctuations can be measured in a short period of time, and only data with large fluctuations can be measured in a long period of time, so that the same accuracy can be obtained in a shorter time than the above-mentioned Jitume Tari.
本発明の他の実施例を第8図に示す。本実施例では、コ
ンピュータ10に像再構成の機能以外に、誤差判定およ
び制御の機能を持たせ、このコンピュータ10とシステ
ム制御部12を連絡させた。Another embodiment of the invention is shown in FIG. In this embodiment, the computer 10 is provided with error determination and control functions in addition to the image reconstruction function, and the computer 10 and the system control section 12 are communicated with each other.
次にこの装置を用いた匍j御方法例を第9図で説明する
。まず従来の方法により測定を行い、像を再構成する。Next, an example of a control method using this device will be explained with reference to FIG. First, measurements are taken using conventional methods and an image is reconstructed.
二相流の<】貝に密度分布が変動する測が対象を測定し
た場合、第9図に示す様な直線状のアーティファクト(
擬画像)が生じ、とれガFil?成に誤差をもたらして
いる。このアーティファクトケまこれと直角方向への並
進動作により得られた透過データに大きな誤差があった
ことを示しているうこの大きな誤差を持つ透過データを
コンピュータ10で割り出し、この地点での測定を再び
行う命令信号をシステム制(2)部に送る。次にこのデ
ータだけを再び測定し、峡初の透過データと平均値をと
り像を再構成する。この実施例によれば、スキャン中に
測が時間、測定回数を変更する必要がないため、電IJ
御が容易になるとともに、測定に要する時間も短羅でき
る。When measuring a two-phase flow where the density distribution fluctuates in the shell, a linear artifact (
Pseudo-image) is generated, and the result is a false image. This causes errors in the composition. This artifact indicates that there was a large error in the transmission data obtained by translation in the direction perpendicular to this point.The computer 10 determines the transmission data that has a large error, and repeats the measurement at this point. A command signal to be executed is sent to the system system (2) section. Next, only this data is measured again, and the image is reconstructed by taking the average value with the initial transmission data of the canyon. According to this embodiment, there is no need to change the measurement time or the number of measurements during scanning, so
In addition to being easier to control, the time required for measurement can also be reduced.
本先明によれば、測定対象の密度分布が変動する場合で
も、寸だ測定対象中に放射線吸収率の大きい物質がある
場合でも、測V時間、測定回数を増加させることにより
、再構成1数の誤差を2.0チ以下にすることができる
。According to the present invention, even if the density distribution of the measurement target fluctuates, even if there is a substance with a high radiation absorption rate in the measurement target, by increasing the V measurement time and the number of measurements, the reconstruction 1 The numerical error can be reduced to 2.0 inches or less.
(7)(7)
第1図、第2図はそれぞれT−R方式、F(、−R方式
OCTスキャナ装置のサンプリング方法を示す図、第3
図は透過データ測定値の時間変化を示すグラフ、第4図
けBWR,(8X8)燃料集合体の説明図、第5図は本
発明の一実施例であるCTスキャナ装置の構成図、第6
図は本発明の一実施例であるCTスキャナ装置の制御方
法の説明図、第7図は測定データの時間平均値と測定時
間の関係を示した図、第8図は本発明の他の実施例を示
す図、第9図はアーティファクトの生じた再構成画像と
透過データの関係を示したiズである。
1・・・放射線源、2・・・検出器、3・・・測定対象
、4・・・燃料集合体、5・・・燃料ビン、6.7・・
・放射線経路、8・・・サンプリング点、9・・・デー
タ収集部、10・・・コンピュータ、11・・・マイコ
ン、12・・・システム制御部、13・・・架台様@制
御部、14・・・並進走行用レール、15・・・円管、
16・・・気体、17・・・液体、18・・・像再54
成領域、19・・・アーティファクト第 I 凶
め2閃
第3図
婆4(2]
=/Thnn へ へ へ ;\第8 凶
/
/3/2
第q 図1 and 2 are diagrams showing the sampling methods of the T-R method and F(,-R method OCT scanner devices, respectively), and FIG.
The figures are graphs showing time changes in transmission data measurement values, Figure 4 is an explanatory diagram of a BWR, (8x8) fuel assembly, Figure 5 is a configuration diagram of a CT scanner device that is an embodiment of the present invention, and Figure 6
The figure is an explanatory diagram of a control method for a CT scanner device which is an embodiment of the present invention, Figure 7 is a diagram showing the relationship between the time average value of measurement data and the measurement time, and Figure 8 is another embodiment of the present invention. An example diagram, FIG. 9, is a diagram showing the relationship between a reconstructed image with artifacts and transparent data. DESCRIPTION OF SYMBOLS 1... Radiation source, 2... Detector, 3... Measurement object, 4... Fuel assembly, 5... Fuel bottle, 6.7...
- Radiation path, 8... Sampling point, 9... Data collection unit, 10... Computer, 11... Microcomputer, 12... System control unit, 13... Frame @ control unit, 14 ...Translational rail, 15...Circular pipe,
16...Gas, 17...Liquid, 18...Image reproduction 54
Formation area, 19...Artifact No. I Abysmal 2nd flash 3rd figure 4 (2) = /Thnn to he to ;\8th evil / /3/2 Fig. q
Claims (1)
システム制御部、および収集した透過データより測定断
面の密度分布を再構成するためのコンピュータからなる
CTスキャナにおい−C1収集した透過データを基に線
源および検出器の制御を行うため、コンピュータと架台
機構制御部およびシステム制御部を連絡させたことを特
徴とするCTスキャナ装置。 2、像再構成用コンピュータ以外に、誤差判定用コンピ
ュータおよび線源、検出器のづU両用コンピュータを備
えていることを特徴とする特許請求の範囲第1項記載O
CTスキャナ装置。 3、コンピュータニ制御用出力端子、システム制御部に
コンピュータからの信号の入力のための入力端子を備え
ていることを特徴とする特許請求範囲第1項記載OCT
スキャナ装置。 4、像再構成プログラム以外に誤差判定用プログラム、
システム制御用プログラムを記憶しているコンピュータ
を備えていることを特徴とする特許請求の範囲第1項記
載OCTスキャナ装置。[Claims] 1. In a CT scanner consisting of a radiation source, a detector, a system control unit for moving these, and a computer for reconstructing the density distribution of the measurement cross section from the collected transmission data - C1 acquisition 1. A CT scanner apparatus, characterized in that a computer is connected to a gantry mechanism control section and a system control section in order to control a radiation source and a detector based on transmitted transmission data. 2. In addition to the image reconstruction computer, the computer includes a computer for error determination and a computer for both radiation sources and detectors.
CT scanner device. 3. The OCT according to claim 1, characterized in that the system control section is equipped with an output terminal for computer control, and an input terminal for inputting signals from the computer.
scanner device. 4. In addition to the image reconstruction program, an error determination program,
2. The OCT scanner device according to claim 1, further comprising a computer storing a system control program.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57000254A JPS58118734A (en) | 1982-01-06 | 1982-01-06 | Ct scanner apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57000254A JPS58118734A (en) | 1982-01-06 | 1982-01-06 | Ct scanner apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS58118734A true JPS58118734A (en) | 1983-07-14 |
Family
ID=11468788
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP57000254A Pending JPS58118734A (en) | 1982-01-06 | 1982-01-06 | Ct scanner apparatus |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58118734A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013164352A (en) * | 2012-02-10 | 2013-08-22 | Central Research Institute Of Electric Power Industry | Visualization method and visualization device for moving object |
-
1982
- 1982-01-06 JP JP57000254A patent/JPS58118734A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013164352A (en) * | 2012-02-10 | 2013-08-22 | Central Research Institute Of Electric Power Industry | Visualization method and visualization device for moving object |
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