JPH06285057A - X-ray transmission image photographing device - Google Patents

Abstract

PURPOSE:To provide the X-ray transmission image photographing device of a thin type being suitable for using by integrating it into an ECT system, etc. CONSTITUTION:This device is provided with an X-ray tube 14 for irradiating a thin sector-like X-ray flux, a horizontal movable bed 1 on which an examinee M is mounted, a belt-like phosphor 16 which is arranged so as to be roughly orthogonal to the longitudinal direction of the bed 1, and detects X rays for transmitting through the examinee M, a telecamera 18 for picking up the belt- like phosphor 16, and an X-ray control part 21 for irradiating successively a pulsative X-ray flux from the X-ray tube 14 in relation to a horizontal movement of the bed 1. Images obtained by irradiating the X rays plural times are synthesized by an image processing part 25 and an X-ray transmission image is displayed on a CRT 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray transmission imaging apparatus, for example, an emission computer tomography (EC
T) The present invention relates to an X-ray transmission image photographing apparatus suitable for clarifying the mutual positional relationship between a nuclear medicine image and each organ of a subject in the apparatus.

[0002]

2. Description of the Related Art As is well known, an ECT device determines the state of accumulation or deposition of radiopharmaceuticals administered to a subject in an organ.
A tomographic image of RI (radioisotope) distribution is obtained by mechanically or electronically scanning from outside the body using a line detector for detection. Since this type of nuclear medicine image has a poor spatial resolution and is a blurred image as a whole, it is difficult to determine the mutual positional relationship between the image and each organ of the subject.

Therefore, a method has been adopted in which an X-ray imaging apparatus, which is separate from the ECT apparatus, is used to irradiate X-rays from the side of the subject, and an X-ray image is taken with a film placed on the opposite side. There is also.

[0004]

However, even if the region of interest of the subject is X-rayed by such a method,
Since the X-ray image and the nuclear medicine image are taken independently of each other, the mutual positional relationship is not always clear. Therefore, it is extremely difficult to specify the anatomical position by the X-ray radiographic image and obtain the nuclear medicine tomographic image at the position by performing the interrelated radiography.

On the other hand, an X-ray television apparatus is attached in front of the ECT apparatus, a television image obtained by X-ray fluoroscopic examination of a subject is digitized and taken into a computer, and from the center of the image to the center of the γ-ray detector. It is possible to obtain a nuclear medicine tomographic image at a desired position by feeding the bed on which the subject is placed to the ECT device side by the distance of, but the image integrator used for fluoroscopy is large. Therefore, the device as a whole becomes extremely large and not practical.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a thin X-ray transmission image photographing apparatus suitable for being used by being incorporated in an ECT apparatus or the like.

[0007]

The present invention has the following constitution in order to achieve such an object. That is, the X-ray transmission image capturing apparatus according to the present invention has a thin fan-shaped X-ray image.
X-ray irradiating means for irradiating a ray bundle, a horizontally movable bed on which the subject is placed, and a band-shaped fluorescence which is arranged substantially orthogonal to the longitudinal direction of the bed and detects X-rays transmitted through the subject. A body, a television camera for picking up an image of the band-shaped phosphor, and a control means for sequentially irradiating the pulsed X-ray flux from the X-ray irradiation means in association with the horizontal movement of the bed.

[0008]

The operation of the present invention is as follows. While the bed on which the subject is placed is horizontally moved, a pulsed thin fan-shaped X-ray flux is sequentially irradiated from the X-ray irradiation means. The pulsed X-ray flux that has passed through the subject is incident on the band-shaped light emitter and is sequentially converted into a visible light emission image. An X-ray transmission image of the subject is obtained by sequentially capturing this emission image with a television camera.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In addition, although an example in which the X-ray transmission imaging apparatus according to the embodiment is incorporated in the ECT apparatus will be described here, the present invention is not limited to this. FIG. 1 is a diagram showing a schematic configuration of the embodiment apparatus, and FIG. 2 is a vertical sectional view of the apparatus body.

In the figure, reference numeral 1 is a horizontally movable bed on which a subject M is placed. 2 is a base having an opening through which the bed 1 can pass. On the side surface of the base 2 opposite to the insertion side of the bed 1 (right side in FIG. 2), E
The γ-ray detector 3 of the CT device is arranged in a ring shape.
Lead shield plates 4 are provided on both side surfaces of the γ-ray detector 3 for preventing γ-rays from entering from a portion of the subject M other than the region of interest.
Is attached. Although the γ-ray detector 3 is fixedly installed in a ring shape in the present embodiment,
The line detector may be rotated to collect data.

A rotary plate 5 having an opening through which the bed 1 can pass is rotatably supported by a plurality of rollers 6 on the side surface of the base 2 opposite to the surface on which the γ-ray detector 3 is attached. . The rotary plate 5 is driven by a drive mechanism (not shown) and can be set at any position.
The X-ray transmission image capturing apparatus 10 according to the embodiment is attached to the rotating plate 5. By attaching the X-ray transmission image radiographing apparatus 10 to the rotary plate 5, the X-ray radiographing can be performed from any direction around the subject M.

The X-ray transmission image photographing apparatus 10 is composed of an X-ray irradiation unit 11 for irradiating a thin fan-shaped X-ray flux, a transmission image photographing unit 12 for detecting transmitted X-rays, and the like.

The X-ray irradiation unit 11 includes an X-ray tube 14 attached to the rotary plate 5 via a bracket 13, and an X-ray tube 14
It includes an irradiation cylinder 15 and the like for forming the X-ray flux irradiated from the above into a thin fan-shaped X-ray flux.

The transmission image photographing unit 12 is arranged on both sides of the bed 1 and is X-shaped.
It is attached at a position facing the line irradiation unit 11, and is configured as follows. A strip-shaped phosphor 16 is horizontally arranged so as to be substantially orthogonal to the longitudinal direction of the bed 1. The phosphor 16 is for converting the X-rays transmitted through the subject M into a visible light image, and is arranged such that its light emitting surface is on the lower side. Below the phosphor 16, there is a reflection mirror 17,
The light from the phosphor 16 is reflected and guided to the television camera 18. The phosphor 16 and the reflection mirror 17 are housed in a dark box 19 and shielded from external light. By bending the optical path by the reflection mirror 17, the transmission image capturing unit 12 can be downsized.

The position of the bed 1 which moves horizontally is detected by a position detector such as the rotary encoder 20, and the position information is given to the X-ray controller 21. X-ray controller 21
Gives an X-ray irradiation command to the high voltage generator 22 connected to the X-ray tube 14 at a predetermined timing based on the input position information. As a result, a pulsed X-ray flux is emitted from the X-ray tube 14.

The television camera 18 is arranged so as to horizontally scan the light emitting surface of the phosphor 16 in its longitudinal direction. The luminescent image captured by the television camera 18 is given to the image processing section 25 via the A / D converter 23 and, if necessary, the logarithmic converter 24. The image processing unit 25 synthesizes a fluoroscopic image of the subject M based on the video signal from the television camera 18, and displays this on the CRT 26.

The measurement data collected by the γ-ray detector 3 of the ECT device is given to the image reconstructing device 27. The image reconstructing device 27 reconstructs a tomographic image of the examination site of the subject M based on the collected measurement data, and displays it on the CRT 28.

The operation panel 29 is used for designating the anatomical position of the tomographic image of the subject and the irradiation timing of X-rays.

Next, the operation of the apparatus of the above embodiment will be described. The operator operates the operation panel 29 to specify the timing of X-ray irradiation. The timing designation of the X-ray irradiation is such that the X-ray is radiated every time the bed 1 advances a certain distance (for example, 1 mm). This designation information is given to the X-ray controller 21. The X-ray controller 21
Depending on the position information from the rotary encoder 20, the high voltage generator 2 is moved every time the bed 1 advances by a designated distance.
X-ray irradiation command is issued to 2. Thereby, the X-ray irradiation unit 11
A pulse-shaped thin fan-shaped X-ray flux is emitted from.

When the X-ray flux that has passed through the subject M enters the phosphor 16, the phosphor 16 emits light, and the emission image is captured by the television camera 18. FIG. 3 is a captured image obtained by one X-ray irradiation, and a hatched area in the drawing is a partial image P of the subject M.

The image processing unit 25 synthesizes one transmission image as follows based on the partial image P obtained for each of a plurality of X-ray irradiations. In the above-mentioned strip-shaped partial image P, a plurality of (for example, 10 to 20) scanning lines SL _{1 are included.}
~ SL _N are included. Therefore, the bed 1 scan line S
Image data of a scanning line corresponding to the same subject region in partial images obtained by irradiating X-rays and shifting the imaged region little by little every time the pitch of L advances The transmission images of the entire examination site are combined by integrating

For example, in the simplified example shown in FIG.
When the partial image P includes _six scan lines SL ₁ to SL ₆ , X-rays are emitted every time the bed 1 moves PC by one pitch of the scan line SL, and the X-rays are obtained six times. For each of the partial images P _{1 to} P ₆ , the data group D of each line SL ₆ to SL ₁ shifted by one line is integrated to obtain the data for one line of the composite image P ₀ .

As described above, if the data for one line of the composite image P ₀ is obtained by a plurality of X-ray photography,
Since the noise component with respect to the signal component is reduced, a transmitted image with good image quality can be obtained.

The bed 1 that has passed through the X-ray transmission image capturing apparatus 10 subsequently enters the opening of the γ-ray detector 3 of the ECT apparatus. The γ-ray detector 3 collects the three-dimensional data of the RI distribution of the examination site and sends the measurement data to the image reconstructing device 27. Here, the image reconstruction device 27 stores the measurement data in association with the position information of the bed 1 given from the rotary encoder 20. Since the distance L between the X-ray transmission image capturing device 10 and the γ-ray detector 3 is known, the image reconstruction device 2
7 and the measurement data stored in the X-ray transmission image capturing apparatus 10
The positional relationship is associated with the transmission image stored in the image processing unit 25.

Therefore, the operator looks at the transmission image displayed on the CRT 26 and uses the operation panel 29 to specify the anatomical position with a cursor or the like. The designation information is given to the image reconstruction device 27. The image reconstructing device 27 reconstructs a tomographic image of the anatomical position designated based on the position information and displays it on the CRT 28.

As described above, according to the apparatus of the present embodiment, since the reconstructed nuclear medicine tomographic image can be clearly understood as to which part of the subject the tomographic plane is, it is useful for the diagnosis of nuclear medicine.

Although a plane mirror is used as the reflecting mirror 17 in the above-described embodiment, a concave reflecting mirror 17a may be used as shown in FIG. With this configuration,
Since the light collection efficiency is increased, the sensitivity of the X-ray transmission image photographing device is increased. Further, when the concave reflection mirror 17a is viewed from the TV camera 18, the emission image is in the width direction (bed moving direction).
Be expanded to. As a result, the number of scanning lines required to scan the full width of the luminescent image increases, so that,
When the data is doubled, the data of two adjacent scanning lines are added to obtain the data of one scanning line.
On the other hand, if the data of adjacent scanning lines are processed as they are without being added as described above, the resolution in the width direction of the phosphor 16 (the body axis direction of the subject) can be increased.

The mounting posture of the X-ray tube 14 is shown in FIG.
Not only the posture as shown in FIG. 2, but also the X-ray tube 14 may be attached while being tilted in order to prevent so-called eclipse by the anode (a phenomenon in which the intensity of X-rays is reduced on one end side of the fan-shaped beam due to being shielded by the anode). Good. Further, in order to reduce the effective focus in all irradiation directions of the fan-shaped beam, the central axis of the X-ray tube 14 is in the moving direction of the bed 1 as in the X-ray CT (it is displaced 90 degrees from the posture of FIG. 1). State).

Furthermore, the X-ray transmission image photographing apparatus according to the present invention can be used not only as an ECT apparatus but also as a scanogram photographing apparatus.

[0030]

As is apparent from the above description, according to the present invention, while moving the bed on which the subject is placed, the subject is sequentially irradiated with a pulsed thin fan-shaped X-ray flux,
The transmitted X-rays are detected by a band-shaped light emitting body arranged so as to be substantially orthogonal to the longitudinal direction of the bed, and a transmission image is obtained by capturing the light emission image with a television camera. It is possible to realize a thin X-ray transmission image capturing device. Therefore, even if this type of apparatus is incorporated into another image diagnostic apparatus such as an ECT apparatus, the size of the entire apparatus does not increase and it is extremely practical.

Further, it is easy to make the band-shaped phosphor larger than the body width of the subject, and a photographed image with a large field of view can be obtained.

Furthermore, since a thin fan-shaped X-ray flux is used, scattered X-rays are less likely to be generated in the subject, and the X-ray
Since the wire bundle is relatively scanned in the body axis direction for shooting,
There is little distortion of the image in the body axis direction, and as a result, an X-ray transmission image with good image quality can be taken.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an apparatus according to an embodiment.

FIG. 2 is a vertical sectional view of an apparatus according to an embodiment.

FIG. 3 is an explanatory diagram of a captured image obtained by one X-ray irradiation.

FIG. 4 is an explanatory diagram showing a technique for obtaining a transmission image from partial images obtained by a plurality of X-ray irradiations.

FIG. 5 is an explanatory diagram of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bed 3 ... γ-ray detector 5 ... Rotating plate 10 ... X-ray transmission image capturing device 11 ... X-ray irradiation unit 12 ... Transmission image capturing unit 14 ... X-ray tube 15 ... Irradiation tube 16 ... Strip fluorescent material 17 ... Reflection Mirror 18 ... Television camera 21 ... X-ray control unit 25 ... Image processing unit 27 ... Image reconstruction device

Claims (1)

[Claims] 1. An X-ray irradiating means for irradiating a thin fan-shaped X-ray flux, a horizontally movable bed on which a subject is placed, and a bed which is arranged so as to be substantially orthogonal to the longitudinal direction of the bed and transmits the subject. A band-shaped phosphor that detects the X-rays, a television camera that images the band-shaped phosphor, and a control unit that sequentially irradiates the pulsed X-ray flux from the X-ray irradiation unit in association with the horizontal movement of the bed. An X-ray transmission image radiographing apparatus comprising: