JPH0822537A - Method and device for generating perspective picture from ct picture - Google Patents
Method and device for generating perspective picture from ct pictureInfo
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- JPH0822537A JPH0822537A JP6174837A JP17483794A JPH0822537A JP H0822537 A JPH0822537 A JP H0822537A JP 6174837 A JP6174837 A JP 6174837A JP 17483794 A JP17483794 A JP 17483794A JP H0822537 A JPH0822537 A JP H0822537A
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- 238000000034 method Methods 0.000 title claims description 7
- 238000010521 absorption reaction Methods 0.000 claims abstract description 50
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- 238000005259 measurement Methods 0.000 abstract description 2
- 239000000654 additive Substances 0.000 abstract 1
- 230000000996 additive effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 6
- 210000001519 tissue Anatomy 0.000 description 5
- 210000000988 bone and bone Anatomy 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000003745 diagnosis Methods 0.000 description 2
- 206010028980 Neoplasm Diseases 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000001959 radiotherapy Methods 0.000 description 1
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、スライス方向で得た複
数のＣＴ画像を編集してそのスライス方向での透視画像
を得る方法及び装置、特に、関心領域の透視画像を得る
に好適な透視画像作成方法及び装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for editing a plurality of CT images obtained in a slice direction to obtain a fluoroscopic image in the slice direction, and more particularly, to a fluoroscopic image suitable for obtaining a fluoroscopic image of a region of interest. The present invention relates to an image creating method and apparatus.
【０００２】[0002]
【従来の技術】特開平４−２６３８４１号は、本件と同
一出願人によるものであり、関心領域をマウスで指定し
て、その指定枠内の画像のみを投影して、スライス方向
の透視像を得る例を開示する。投影は、１つのＣＴ画像
の任意の方向から行うものとしている。この投影によっ
て、１つのＣＴ像からは、その投影方向からの積算（総
加算又は加算平均）値が得られる。そしてスライス方向
に沿う複数のＣＴ像について同様の投影を行う。かくし
て得たスライス方向に沿う複数のＣＴ像それぞれに得た
積算値を、そのスライス方向に沿って配列することでス
ライス方向に沿う１つの透視像を得る。2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 4-263841 is filed by the same applicant as the present application, in which a region of interest is designated by a mouse and only an image within the designated frame is projected to form a perspective image in a slice direction. An example of obtaining is disclosed. The projection is performed from an arbitrary direction of one CT image. By this projection, from one CT image, an integrated value (total addition or addition average) from the projection direction can be obtained. Then, similar projection is performed on a plurality of CT images along the slice direction. By arranging the integrated values obtained in each of the plurality of CT images along the slice direction thus obtained along the slice direction, one perspective image along the slice direction is obtained.
【０００３】[0003]
【発明が解決しようとする課題】上記従来例は、関心領
域を囲む縦と横との枠を定め、枠外の画素は“０”に
し、枠内のみ透視するやり方をとる。しかし、ＣＴ像か
ら作成する透視画像は投影方向の全データを総加算して
作成するため、患部（ＣＴ値の小さいデータ）が骨（Ｃ
Ｔ値の高いデータ）に隠れて見えない問題があった。ま
た、患部と周辺の正常組織とのＣＴ値の差はあまり大き
くないため見分けがつけられない問題があった。In the above-mentioned conventional example, the vertical and horizontal frames surrounding the region of interest are defined, pixels outside the frame are set to "0", and only the inside of the frame is seen through. However, since a fluoroscopic image created from a CT image is created by totalizing all data in the projection direction, the affected area (data with a small CT value) is a bone (C
There was a problem that it was hidden behind the data with a high T value). In addition, there is a problem that the CT values of the affected area and the surrounding normal tissue are not so large that they cannot be distinguished.
【０００４】本発明の目的は、骨などで患部が見えなく
なることを防ぎ、患部と周辺の正常組織が明瞭に表示で
きる透視画像を作成する方法及び装置を提供するもので
ある。An object of the present invention is to provide a method and apparatus for creating a fluoroscopic image capable of preventing the affected part from becoming invisible due to bone or the like and clearly displaying the affected part and normal tissue around the affected part.
【０００５】[0005]
【課題を解決するための手段】本発明は、異なるスライ
ス位置毎の複数のＣＴ画像について、計測Ｘ線吸収係数
値から求めたＣＴ値を任意の人為的に定めた吸収係数値
に変換して、吸収係数値画像を得、各吸収係数値画像毎
にその画面の任意の方向から投影を行って投影データを
得、この投影データを配列して透視像を得る、ＣＴ画像
からの透視画像作成方法を開示する。The present invention converts a CT value obtained from a measured X-ray absorption coefficient value into an arbitrary artificially determined absorption coefficient value for a plurality of CT images at different slice positions. , An absorption coefficient value image is obtained, projection is performed for each absorption coefficient value image from any direction on the screen, projection data is obtained, and a perspective image is obtained by arranging this projection data. A method is disclosed.
【０００６】本発明は、ＣＴ値と吸収係数値との関係
を、関数として設定する手段と、異なるスライス位置毎
の複数のＣＴ像Ｉ1、Ｉ2、…、Ｉnを格納するメモリ
と、各ＣＴ像Ｉ1、Ｉ2、…、Ｉnの各画素について上記
関数を利用してそのＣＴ値を上記関数を利用して対応す
る吸収係数値に変換して吸収係数値画像Ｉ′1、Ｉ′2、
…、Ｉ′nを得る手段と、吸収係数値画像Ｉ′1、
Ｉ′2、…、Ｉ′nのそれぞれ毎に、各画像面の任意の方
向から投影を行って投影画素を得る手段と、吸収係数値
画像Ｉ′1、Ｉ′2、…、Ｉ′n毎に得られる投影画素
を、その吸収係数値画像Ｉ′1、Ｉ′2、…、Ｉ′nの順
に配列してスライス方向の透視画像Ｇを得る手段と、よ
り成るＣＴ画像からの透視画像作成装置を開示する。According to the present invention, means for setting the relationship between the CT value and the absorption coefficient value as a function, and a memory for storing a plurality of CT images I 1 , I 2 , ..., I n for different slice positions, , I n , the CT value of each pixel of each of the CT images I 1 , I 2 , ..., I n is converted into a corresponding absorption coefficient value by using the function, and the absorption coefficient value image I ′ 1 , I '2,
..., 'means for obtaining n, absorption coefficient value image I' I 1,
I '2, ..., I' for each n, and means for obtaining a projection pixel by performing the projection from an arbitrary direction of the image plane, the absorption coefficient value image I '1, I' 2, ..., I 'n A projection image obtained from each CT image is formed by arranging the projection pixels obtained for each of them in the order of the absorption coefficient value images I ′ 1 , I ′ 2 , ..., I ′ n to obtain a perspective image G in the slice direction. A creation device is disclosed.
【０００７】[0007]
【作用】本発明によれば、被検体のスライス位置を変え
てスキャン計測で得た複数のＣＴ像について、ＣＴ値−
吸収係数値の関係を示す関数を用いて、ＣＴ値を任意の
吸収係数値に変換し、この変換後の吸収係数値画像をそ
の画像平面に沿って投影し、この投影データを並べて透
視像を作成する。According to the present invention, the CT value of a plurality of CT images obtained by scan measurement while changing the slice position of the subject is-
The CT value is converted into an arbitrary absorption coefficient value using a function indicating the relationship of the absorption coefficient values, the converted absorption coefficient value image is projected along the image plane, and the projection data are arranged to form a perspective image. create.
【０００８】[0008]
【実施例】本発明の実施例を図１により説明する。ある
被検体に対して、スライス位置ｉ1〜ｉnまで、テーブル
送りｌピッチでｎ回のスキャン計測でＣＴ像１（Ｉ1〜
Ｉn）を作成する。ＣＴ像１（Ｉ1〜Ｉn）の各画像の各
画素のＣＴ値データを、操作者が設定した、ＣＴ値・吸
収係数値関数を示す変換テーブル２により変換し、変換
後の吸収係数値画像３（Ｉ′1〜Ｉ′n）を得る。この変
換テーブルの例では、診断上関心のあるＣＴ値範囲（Ｃ
Ｔmin〜ＣＴmax）を直線的に吸収係数値データに変換
し、範囲外データの吸収係数値を０として変換してい
る。この変換テーブルは診断目的により、図２（ａ）〜
（ｅ）の様に人為的に種々設定することができる。EXAMPLE An example of the present invention will be described with reference to FIG. For a subject, to slice positions i 1 through i n, CT images 1 (I 1 ~ in n scans measured by table feed l pitch
I n ). The CT value data of each pixel of each image of the CT images 1 (I 1 ~I n), the operator has set, converted by the conversion table 2 indicating the CT value and absorption coefficient value function, the absorption coefficient value after the conversion image 3 obtain (I '1 ~I' n) . In the example of this conversion table, the CT value range (C
T min to CT max ) is linearly converted to absorption coefficient value data, and the absorption coefficient value of the out-of-range data is converted to 0. This conversion table is shown in FIG.
Various settings can be made artificially as in (e).
【０００９】ここで図１の変換テーブル及び図２の変換
テーブルについて説明する。画像再構成では、Ｘ線吸収
係数値が二次元的に得られる。二次元的なＸ線吸収係数
値をそのまま表示画素として利用したのでは実際の断層
画像には見えにくい。また、係数値の最小と最大との幅
も表示画面の階調度の最小と最大との幅に一致しない。
こうしたことから、Ｘ線吸収係数値を相対値として表現
するやり方がとられる。これがＣＴ値である。ＣＴ値は
例えば下式で算出する。The conversion table of FIG. 1 and the conversion table of FIG. 2 will be described. In image reconstruction, X-ray absorption coefficient values are obtained two-dimensionally. If the two-dimensional X-ray absorption coefficient value is used as it is as a display pixel, it is difficult to see it in an actual tomographic image. Further, the minimum and maximum widths of the coefficient values do not match the minimum and maximum widths of the gradation of the display screen.
Therefore, the X-ray absorption coefficient value is expressed as a relative value. This is the CT value. The CT value is calculated, for example, by the following formula.
【００１０】[0010]
【数１】組織のＣＴ値＝｛１０００×（組織のＸ線吸収
係数値）−（水のＸ線吸収係数値）｝／（水のＸ線吸収
係数値） 数１よりわかるように、空気のＸ線吸収係数は０である
から、そのＣＴ値は−１０００に、また、水のＣＴ値は
０に、更に、骨のＸ線吸収係数は水の約２倍であるため
に、骨のＣＴ値は約１０００となる。各種人体組織のＣ
Ｔ値は図３（ａ）に示すようになるために、ＣＴ画像よ
り形態的診断や、出血、腫瘍などの有無、部位などが診
断できる。## EQU1 ## CT value of tissue = {1000 × (X-ray absorption coefficient value of tissue)-(X-ray absorption coefficient value of water)} / (X-ray absorption coefficient value of water) Has an X-ray absorption coefficient of 0, its CT value is -1000, water has a CT value of 0, and bone has an X-ray absorption coefficient of about twice that of water. The CT value is about 1000. C of various human tissues
Since the T value is as shown in FIG. 3A, morphological diagnosis, presence or absence of bleeding, tumor, etc., site, etc. can be diagnosed from the CT image.
【００１１】Ｘ線ＣＴ装置においては、ＣＴ画像の表示
にあたって、その濃淡情報とＣＴ値の関係を図３（ｂ）
に示すように調整できるようになっている。そのため
に、ＣＴ画像の診断にあたって、診断しやすいようにウ
ィンドウ幅とウィンドウレベルを調整して観察したり、
フィルムに撮影したりしている。こうした図３（ａ）、
（ｂ）に従ってＣＴ値が得られるが、こうして得られた
ＣＴ値に対して、本実施例では、人為的に定めたＣＴ値
−Ｘ線吸収係数値関数を用意しておき、この関数に従っ
て、数１や図３（ｂ）で得たＣＴ値を再度Ｘ線吸収係数
値に換算せしめることにした。こうしてＣＴ画像Ｉ1〜
Ｉnから吸収係数値画像Ｉ′1〜Ｉ′nを得る。In the X-ray CT apparatus, when displaying a CT image, the relationship between the grayscale information and the CT value is shown in FIG. 3 (b).
It can be adjusted as shown in. Therefore, when diagnosing a CT image, the window width and window level are adjusted for observation to facilitate diagnosis,
I shoot on film. As shown in FIG.
Although the CT value is obtained according to (b), in this embodiment, an artificially determined CT value-X-ray absorption coefficient value function is prepared for the CT value thus obtained, and according to this function, It was decided to convert the CT value obtained from the equation 1 and FIG. 3B into the X-ray absorption coefficient value again. Thus CT image I 1 ~
The absorption coefficient value images I ′ 1 to I ′ n are obtained from I n .
【００１２】図１の直線の例は、関心ＣＴ値範囲（ＣＴ
min〜ＣＴmax）について、ＣＴ値を直線によりＸ線吸収
係数値に変換した例である。この直線には数１の式も含
まれる。An example of the straight line in FIG. 1 is a CT value range of interest (CT
min- CT max ) is an example in which the CT value is converted into an X-ray absorption coefficient value by a straight line. This straight line also includes the expression of Equation 1.
【００１３】図２（ａ）は、ＣＴ値が−１０００とＣＴ
iとの範囲では直線にすると共に、関心領域のＣＴ値範
囲（ＣＴmin〜ＣＴmax）はこの直線で得られる換算値よ
りも更に一段と大きな換算値にしたものである。図２
（ｂ）は、Ｓ字に近い特性を持たせた例、図２（ｃ）は
ＣＴminよりも小さいＣＴ値では吸収値を零にし、関心
領域のＣＴ値範囲は直線化し、ＣＴmaxよりも大きいＣ
Ｔ値では最大吸収値を維持させた例、図２（ｄ）は図１
の例そのもの、図２（ｅ）は互いに異なる２つの関心領
域のＣＴ値範囲を設定した例である。FIG. 2A shows that the CT value is -1000 and CT.
The range of i is a straight line, and the CT value range (CT min to CT max ) of the region of interest is a converted value that is much larger than the converted value obtained by this straight line. Figure 2
FIG. 2B shows an example in which the characteristics are close to S-shaped. In FIG. 2C, the absorption value is set to zero at a CT value smaller than CT min , the CT value range of the region of interest is linearized, and the CT value range is larger than CT max. Big C
An example in which the maximum absorption value is maintained at the T value, FIG.
FIG. 2E itself is an example in which the CT value ranges of two different ROIs are set.
【００１４】次に、上記データ変換した全てのＣＴ像対
応の吸収値画像Ｉ′1〜Ｉ′nに対して、画像Ｉ′毎に二
次元の座標を持つ画像データから、各画像に沿う平面上
の任意の角度方向に加算平均をとり、一次元の座標の投
影像４を作成する。この際、角度は画像の０゜〜１８０
゜（１８０゜〜３６０゜は、投影方向が０゜〜１８０゜
と１８０゜異なるだけで全く同一。従って１８０゜〜３
６０゜の範囲は不要）の範囲でどの方向から見た透視画
像を作成するのかを示し、この機能を操作者に選ばせ
る。図１の例では角度がＣＴ画像に対して９０゜の水平
方向（ｘ座標方向）とした。[0014] Next, the absorption values of all of the CT images corresponding to the data conversion for the image I '1 ~I' n, each image I 'from the image data with two-dimensional coordinates, the plane along each image An arithmetic mean is taken in the above arbitrary angle direction to create a projected image 4 of one-dimensional coordinates. At this time, the angle is 0 ° to 180 ° of the image.
(180 ° to 360 ° is exactly the same except that the projection direction differs from 0 ° to 180 ° by 180 °. Therefore, 180 ° to 3 °
In the range of 60 ° is unnecessary), it shows from which direction the perspective image is viewed, and the operator is allowed to select this function. In the example of FIG. 1, the angle is 90 ° with respect to the CT image in the horizontal direction (x coordinate direction).
【００１５】投影像４の作成方法を水平方向からの投影
例の事例で示すと以下となる。 （１）、画像Ｉ′1に対する投影。水平方向からの投影
によって、次のｋ＋１個の投影画素ｉ′1（０）〜ｉ′1
（ｋ）を得る。式の中で、Ｉ′1（０、０）はｘ＝０、
ｙ＝０位置でのＩ′1の画素である。他も同じ考え方で
ある。 ｉ′1（０）＝｛Ｉ′1（０、０）＋Ｉ′1（１、０）＋…＋Ｉ′1（ｊ、０）｝ ／（ｊ＋１） ｉ′1（１）＝｛Ｉ′1（０、１）＋Ｉ′1（１、１）＋…＋Ｉ′1（ｊ、１）｝ ／（ｊ＋１） ……………………………… ｉ′1（ｋ）＝｛Ｉ′1（０、ｋ）＋Ｉ′1（１、ｋ）＋…＋Ｉ′1（ｊ、ｋ）｝ ／（ｊ＋１） （２）Ｉ′2に対する投影。投影画素をｉ′2とすると、
次のｋ＋１個の投影画素ｉ′2（０）〜ｉ′2（ｋ）を得
る。 ｉ′2（０）＝｛Ｉ′2（０、０）＋Ｉ′2（１、０）＋…＋Ｉ′2（ｊ、０）｝ ／（ｊ＋１） ｉ′2（１）＝｛Ｉ′2（０、１）＋Ｉ′2（１、１）＋…＋Ｉ′2（ｊ、１）｝ ／（ｊ＋１） ……………………………… ｉ′2（ｋ）＝｛Ｉ′2（０、ｋ）＋Ｉ′2（１、ｋ）＋…＋Ｉ′2（ｊ、ｋ）｝ ／（ｊ＋１） （３）、以下、同様にＩ′3、…、Ｉ′nについての投影
画素を求める。Ｉ′nの例は以下となる。 ｉ′n（０）＝｛Ｉ′n（０、０）＋Ｉ′n（１、０）＋…＋Ｉ′n（ｊ、０）｝ ／（ｊ＋１） ｉ′n（１）＝｛Ｉ′n（０、１）＋Ｉ′n（１、１）＋…＋Ｉ′n（ｊ、１）｝ ／（ｊ＋１） ……………………………… ｉ′n（ｋ）＝｛Ｉ′n（０、ｋ）＋Ｉ′n（１、ｋ）＋…＋Ｉ′n（ｊ、ｋ）｝ ／（ｊ＋１） このように、水平方向からの投影によって１つのＣＴ画
像からｋ＋１個の投影像が得られる。これが投影像４で
ある。尚（ｊ＋１）で除算したがこれをせずに単なる総
加算のみでもよい。The method of creating the projected image 4 will be described below by way of an example of an example of projection from the horizontal direction. (1) Projection on the image I ′ 1 . By the projection from the horizontal direction, the next k + 1 projected pixels i ′ 1 (0) to i ′ 1
Get (k). In the formula, I ′ 1 (0,0) is x = 0,
y = 0 is I '1 pixel at location. Others have the same idea. i ′ 1 (0) = {I ′ 1 (0,0) + I ′ 1 (1,0) + ... + I ′ 1 (j, 0)} / (j + 1) i ′ 1 (1) = {I ′ 1 (0,1) + I ' 1 (1,1) + ... + I' 1 (j, 1)} / (j + 1) …………………………………… i ′ 1 (k) = {I ′ Projection on 1 (0, k) + I ′ 1 (1, k) + ... + I ′ 1 (j, k)} / (j + 1) (2) I ′ 2 . If the projection pixel is i ′ 2 ,
The next k + 1 projected pixels i ′ 2 (0) to i ′ 2 (k) are obtained. i '2 (0) = { I' 2 (0,0) + I '2 (1,0) + ... + I' 2 (j, 0)} / (j + 1) i '2 (1) = {I' 2 (0,1) + I ' 2 (1,1) + ... + I' 2 (j, 1)} / (j + 1) …………………………………… i ′ 2 (k) = {I ′ 2 (0, k) + I ′ 2 (1, k) + ... + I ′ 2 (j, k)} / (j + 1) (3), and so on for projection pixels for I ′ 3 , ..., I ′ n Ask for. Examples of I 'n becomes less. i 'n (0) = { I' n (0,0) + I 'n (1,0) + ... + I' n (j, 0)} / (j + 1) i 'n (1) = {I' n (0,1) + I ' n (1,1) + ... + I' n (j, 1)} / (j + 1) …………………………………… i ′ n (k) = {I ′ n (0, k) + I ′ n (1, k) + ... + I ′ n (j, k)} / (j + 1) Thus, by projecting from the horizontal direction, k + 1 projected images are obtained from one CT image. can get. This is the projected image 4. Although the division is made by (j + 1), the total addition may be made without doing this.
【００１６】次に、投影像４から透視像（Ｇ）５を得
る。この算出法は以下となる。即ち、透視像５は、投影
像４を画像Ｉ′1→Ｉ′2→…、Ｉ′nの順（スライス順
序）に並べることで求まる。並べた結果を図４に示す。
かくして得た図４の画像は、スライス方向の透視像５と
なる。アドレスは（Ｘ、Ｙ）で示してある。尚、図１で
は透視像５として内部画像５Ａと外部画像５Ｂとを示し
ている。関心領域が５Ａのみの場合もあれば、５Ａと５
Ｂとの２つの場合があるためである。５Ａのみであれば
当然に５Ａのみの透視像が得られることになる。透視像
５は、表示器６に送り表示させる。ここで、もし、その
透視画像を表示する際の画像の画素がテーブル送り量ｌ
と一致しない場合は、補間で新たな画素を作り出し表示
させればよい。Next, a perspective image (G) 5 is obtained from the projected image 4. This calculation method is as follows. That is, the perspective image 5 is obtained by arranging the projection images 4 in the order of the images I ′ 1 → I ′ 2 → ..., I ′ n (slice order). The aligned results are shown in FIG.
The image of FIG. 4 thus obtained becomes a perspective image 5 in the slice direction. The address is indicated by (X, Y). In FIG. 1, an internal image 5A and an external image 5B are shown as the perspective image 5. In some cases, the region of interest is only 5A, and in other cases 5A and 5A
This is because there are two cases with B. If only 5A is used, naturally a perspective image of only 5A is obtained. The perspective image 5 is sent to the display device 6 and displayed. Here, if the pixel of the image when displaying the perspective image is the table feed amount l
If it does not match, a new pixel may be created by interpolation and displayed.
【００１７】図５は投影角度θの例を示す図であり、水
平方向はθ＝０で左から右（又は右から左）への投影
例、垂直方向はθ＝９０゜で上から下（又は下から上）
への投影例、その他に任意の投影角度θ＝θrの例を示
す。FIG. 5 is a diagram showing an example of the projection angle θ. An example of projection from left to right (or right to left) with θ = 0 in the horizontal direction, and from top to bottom (θ = 90 ° in the vertical direction). Or from bottom to top)
In addition to the above, an example of an arbitrary projection angle θ = θ r is shown.
【００１８】[0018]
【発明の効果】本発明によれば、診断目的に応じて、Ｃ
Ｔ値−吸収係数値関数を適宜設定することで、関心領域
が骨などで隠れない様にしたり、関心領域と周辺部のＣ
Ｔ値差が小さくても強調した透視画像を作成することが
できる。かくして診断能力が上がる。また、歪みのない
透視画像で関心領域が明瞭に表示できるため、放射線治
療する際の位置決めが正確で容易になる。According to the present invention, C
By appropriately setting the T value-absorption coefficient value function, it is possible to prevent the region of interest from being obscured by bones, and the C of the region of interest and the peripheral portion.
Even if the T-value difference is small, an emphasized perspective image can be created. Thus, diagnostic ability is improved. Further, since the region of interest can be clearly displayed on the fluoroscopic image without distortion, the positioning at the time of radiotherapy is accurate and easy.
【図１】本発明の画像作成装置の実施例図である。FIG. 1 is a diagram illustrating an embodiment of an image creating apparatus of the present invention.
【図２】本発明のＣＴ値−吸収係数値関数の各種例を示
す図である。FIG. 2 is a diagram showing various examples of a CT value-absorption coefficient value function of the present invention.
【図３】ＣＴ値の付与例を示す図である。FIG. 3 is a diagram showing an example of giving a CT value.
【図４】本発明の実施例で得る透視画像を示す図であ
る。FIG. 4 is a diagram showing a perspective image obtained in an example of the present invention.
【図５】投影角度の例を示す図である。FIG. 5 is a diagram showing an example of projection angles.
１ ＣＴ画像（Ｉ1〜Ｉn） ２ ＣＴ値−吸収係数値関数テーブル ３ 変換後の画像（Ｉ′1〜Ｉ′n） ４ 投影像 ５ 透視像 ６ 画像表示器1 CT image (I 1 ~I n) 2 CT value - image after the absorption coefficient value function table 3 conversion (I '1 ~I' n) 4 projected image 5 fluoroscopic image 6 image display
Claims (2)
ついて、計測Ｘ線吸収係数値から求めたＣＴ値を、任意
の人為的に定めた吸収係数値に変換して、吸収係数値画
像を得、 各吸収係数値画像毎にその画面の任意の方向から投影を
行って投影データを得、 この投影データを配列して透
視像を得る、 ＣＴ画像からの透視画像作成方法。1. An absorption coefficient value image is obtained by converting CT values obtained from measured X-ray absorption coefficient values for a plurality of CT images at different slice positions into arbitrary artificially determined absorption coefficient values. A method for creating a perspective image from a CT image, in which projection data is obtained by projecting each absorption coefficient value image from an arbitrary direction on the screen, and the projection data is arranged to obtain a perspective image.
て設定する手段と、 異なるスライス位置毎の複数のＣＴ像Ｉ1、Ｉ2、…、Ｉ
nを格納するメモリと、 各ＣＴ像Ｉ1、Ｉ2、…、Ｉnの
各画素について上記関数を利用してそのＣＴ値を上記関
数を利用して対応する吸収係数値に変換して吸収係数値
画像Ｉ′1、Ｉ′2、…、Ｉ′nを得る手段と、 吸収係数値画像Ｉ′1、Ｉ′2、…、Ｉ′nのそれぞれ毎
に、各画像面の任意の方向から投影を行って投影画素を
得る手段と、 吸収係数値画像Ｉ′1、Ｉ′2、…、Ｉ′n毎に得られる
投影画素を、その吸収係数値画像Ｉ′1、Ｉ′2、…、
Ｉ′nの順に配列してスライス方向の透視画像Ｇを得る
手段と、より成るＣＴ画像からの透視画像作成装置。2. A means for setting a relationship between a CT value and an absorption coefficient value as a function, and a plurality of CT images I 1 , I 2 , ..., I for different slice positions.
A memory for storing n and the CT value of each pixel of each CT image I 1 , I 2 , ..., I n is converted into a corresponding absorption coefficient value using the above function and absorbed. coefficient value image I '1, I' 2, ..., ' means for obtaining n, absorption coefficient value image I' I 1, I '2 , ..., I' for each n, an arbitrary direction of the image plane means for obtaining a projection pixel by performing the projection from the absorption coefficient value image I '1, I' 2, ..., ' the projection pixels obtained for each n, the absorption coefficient value image I' I 1, I '2 , ...
A fluoroscopic image creating device from a CT image, comprising: means for obtaining a fluoroscopic image G in the slice direction by arranging in order of I ′ n .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6174837A JPH0822537A (en) | 1994-07-05 | 1994-07-05 | Method and device for generating perspective picture from ct picture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6174837A JPH0822537A (en) | 1994-07-05 | 1994-07-05 | Method and device for generating perspective picture from ct picture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0822537A true JPH0822537A (en) | 1996-01-23 |
Family
ID=15985526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6174837A Pending JPH0822537A (en) | 1994-07-05 | 1994-07-05 | Method and device for generating perspective picture from ct picture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0822537A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998015226A1 (en) * | 1996-10-08 | 1998-04-16 | Hitachi Medical Corporation | Method and apparatus for forming and displaying image from a plurality of sectional images |
| JP2001351093A (en) * | 2000-04-05 | 2001-12-21 | Hitachi Medical Corp | Medical image display device |
-
1994
- 1994-07-05 JP JP6174837A patent/JPH0822537A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998015226A1 (en) * | 1996-10-08 | 1998-04-16 | Hitachi Medical Corporation | Method and apparatus for forming and displaying image from a plurality of sectional images |
| US6990231B2 (en) | 1996-10-08 | 2006-01-24 | Hitachi Medical Corporation | Method and apparatus for forming and displaying projection image from a plurality of sectional images |
| JP2001351093A (en) * | 2000-04-05 | 2001-12-21 | Hitachi Medical Corp | Medical image display device |
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