JPS60117105A - Radiant ray scintillator - Google Patents

Abstract

PURPOSE:To intensity strength of a radiation source without enlarging the focus of the radiation source, by arranging a radiant ray emitted from a plurality of radiation sources in such a way that it is emitted in a fan-shape from a single focus and detecting this radiant ray after passing through the specimen. CONSTITUTION:A group of radiant rays 1 is shaped as a plurality of radiant ray sources 1-1-1-320 arranged in a fan-shape. By this, the plural radiant rays be have in such a way that they were emitted from an imaginery focus O. A collimetor 3 is attached to each radiant ray source. A specimen 4 is fixed on a turn table 4a. Radiant ray detectors 5-1-5-320 corresponding to a plurality of radiant ray sources are installed onto radiant ray source group 5. Thus, the focus of radiant ray source becomes smaller, and at the same time, its strength is intensified and space resolution capacity and permeability are improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The radiation of the present invention, such as a CT scanner, which irradiates a radiation source onto an object to be measured and obtains transmission data to obtain information on the shape, internal structure, etc. of the object to be measured. The present invention relates to measurement devices, and particularly to improvements in the structure of their radiation sources.

[Technical background of the invention and its problems]

This type of radiation measuring device includes CT scanners and crown thickness gauges. For example, CT scanners use X-rays, radioisotopes, radioisotopes, and
I) is used. A radiation source using a radioisotope is, for example, a cylindrical radioisotope with a diameter of 1 [■] and a length of 1 [■] made of stainless steel.
ji: It is stored in a capsule. By the way, in CT scanners that use well-corinated fan-shaped radiation called second generation, third generation, and fourth generation, the focal point of the radiation source is made smaller in order to improve spatial resolution. This is required. In other words, the radiation source has a small focal point S1 as shown in FIG.
A device is required that emits radiation R1 in a fan shape from this focal point S1. In contrast, as shown in Figure 1(b), 5
．． Furthermore, if the focal point S2 is large, the radiation R2 will be scattered, resulting in a tomographic image obtained with poor spatial resolution.

However, in order to widen the measurement range and improve the ability of radiation to penetrate depending on the object to be measured, a large amount of radioisotope must be used to increase the intensity of the radiation. This increases the size of the radiation source and necessarily increases its focus.

In this way, in order to improve the spatial resolution, the focal point must be made smaller, and in order to improve the transmission ability, the focal point must be made larger, and there is a contradictory relationship between the two.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to provide a radiation measuring device that can minimize the focus of a radiation source and increase the intensity of the radiation source. [Summary] The present invention emits radiation from a group of radiation sources arranged so that the radiation from these radiation sources is emitted from one focal point in a fan shape, and the radiation that has passed through the entire object to be inspected is emitted. This is a radiation measuring device that detects radiation using a plurality of radiation detectors and obtains information about the object to be measured based on these detection signals.

[Embodiments of the invention]

Hereinafter, the first embodiment of the present invention will be explained with reference to FIGS. 2 to 3.
This will be explained with reference to Figures (a) and (Cb). FIG. 2 is a configuration diagram of a radiation measuring device according to the present invention in which a data acquisition system and image configuration algorithm similar to those of a third generation OCT scanner are applied. In FIG. 2, reference numeral 1 denotes a radiation source group, and this radiation source group 1 consists of 320 radiation sources 1-1 to 1, each containing a radioisotope and stored in an f-cell.
-320 are housed in the radiation source container 2 in a fan-shaped arrangement so that the radiation emitted from these radiation sources 1-1 to 1-320 is radiated from a virtual focus d. That is, in the radiation source group 1, grooves 1&-1 to 1a-320 are formed to house 320 radiation sources 1-1 to J-320, respectively, as shown in FIG. 3(a). The radiation from each radiation source is the concave groove 1a-1 to I.
Each is collimated by a ts-320. Further, these radiation beams are sufficiently collimated by the collimator 3 so that the fan-shaped beam surfaces formed from each radiation beam are coplanar and sufficiently collimated. The collimator 3 consists of two collimating plates Ja and 3b formed to have the same radius of curvature as the radiation source container 2, as shown in FIG. 3(a), for example. By collimating both horizontally and vertically with respect to the beam plane in this manner, the beams emitted from each of the radiation sources 1-1 to 1-320 become sufficiently narrow collimated pencil beams. The collimator is shown in Figure 3 (b
) may be formed integrally with the radiation source container 2.

That is, radiation emission ports 2-1 to 2- are provided in the radiation source container 2a.
320 and using an RI rod-shaped radiation source as a radiation source, a well-collimated radiation beam can be obtained with easy processing and construction.

The object to be inspected 4 is placed on a turntable 4a, and its rotation is driven and controlled by a mechanism control section and a mechanism drive section (not shown). That is, when a command to collect image data of the object 4 to be inspected is supplied from the control section 12, the mechanism control section controls the mechanism drive section to rotate the turntable 4a at a predetermined number of rotations, so that the object 4 to be inspected can be viewed from all angles. to obtain projection data. A radiation detector group 5 is installed opposite the radiation source group 1 with the inspected object 4 interposed therebetween. In addition, a collimating plate group 5 having the same structure as the collimator 3 on the front side of the radiation detector group 5 detects the radiation transmitted through the inspected object 4 from the radiation source group '1. 5-1 to 5-3
20 respectively as virtual focal point 100 and radiation source 1-1 to J-32
It is provided on a straight line passing through 0. In front of these radiation detectors 5-1 to 5-320, a radiation source 1-
Correction devices 7-1 to 7-320 are provided for correcting variations in radiation intensity of 1 to 1-320.

The correction devices 7-1 to 7-320 are constituted by shielding plates made of lingsten, for example, and each of the radiation source numbers 1 to 1
The transmission thickness can be adjusted according to the intensity of -320.

And detection of each radiation detector 5-1 to 5-J20 (i3
The issue is taken into the data collection department io and is a well-known 3rd generation CT.
It is configured to be collected as projection data similar to projection data collected by a scanner and sent to the image reconstruction unit 11. The image reconstruction unit 11 reconstructs the data from the data collection unit 10 using a well-known image reconstruction algorithm, that is, performs mathematical processing to restore it to a two-dimensional image. The control unit 12 is the image reconstruction unit 11
The two-dimensional image obtained is converted into a video signal and sent to the monitor television 13.

Next, the operation of the apparatus configured as described above will be explained. At the start of the test, the test subject 4 is in a position where the radiation from the radiation source group 1 is not applied. Therefore, radiation source group 1
When radiation is emitted from the radiation sources 1-1 to J-320, these radiations are emitted as if they were emitted from the virtual focus d. Furthermore, these radiations are transmitted through the collimator 3
is radiated to the same plane by Therefore, these radiations pass through the correction devices 7-1 to 7-320 and reach the radiation detector 5.
-1 to reach 5-320.

The inspection of the object 4 to be inspected is performed while rotating the object 4, for example, in the direction of arrow 0). The object to be inspected 4 is rotated by a minute angle in one rotation operation, and radiation is emitted from the radiation sources 1-1 to 1-320. The radiation that has passed through the 8+11 constant body 4 is detected by the discharge i-line detectors 5-1 to 5-320, and the detection signals from these radiation detectors 5-1 to 5-320 are collected by the data collection unit 10. . Then, the inspected object 4 is set to, for example, (180 degrees + radiation fan angle α of radiation source group 1)
The inspection ends when it rotates.

The projection data collected by the data collection unit 11 is sent to the image reconstruction unit 11, which reconstructs the data and restores it to a two-dimensional image. The obtained two-dimensional image is converted into a video signal by the control section 12 and sent to the monitor television 13. This makes Sonita Telepiji.

A tomographic image of the subject 4 is displayed on the screen 13 .

In this way, in this apparatus, radiation sources 1-1 to 1-3
Radiation is emitted from the radiation source group 1 arranged so that the radiation is emitted from a virtual focus d in 20 colors, and the radiation is transmitted to the radiation detectors 5-1 to 5-32.
Since the tomographic image of the object 4 to be inspected is obtained by detecting at 0, the radiation intensity of the radiation source can be increased without increasing the focal point of the radiation source. Well, with this device,
Even if the intensity of each radiation from the radiation sources 1-1 to 1-320 is small, the intensity of the radiation as a whole is large. If one attempts to obtain radiation of the same intensity as this radiation with one radiation source, the focus of that radiation source will become large.

By applying the radiation source group 1 of this apparatus to a CT scanner, the spatial resolution of the CT scanner can be improved. That is, the radiation from the radiation source group 1 appears to be radiated from the virtual focus 6, and the intensity of the radiation can be increased.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 4, 20 is a radiation source group, and 21
is the radiation detection group. The radiation source group 20 includes radiation sources 2
0h to 20g are arranged so that the radiation from these radiation sources 20 & 20g is converged to form a focal point "Oa" at a predetermined distance from the radiation source group 20. Radiation detector group 21, radiation detectors 21h to 21g are respectively arranged so as to detect radiation passing through the focal point Oa.In addition, 22a to 22
g is a correction device.

It goes without saying that even with this configuration, the same effects as in the first embodiment can be obtained. Furthermore, in this second embodiment, the spatial resolution of the CT scanner can be improved by moving the position of the object 4 to be inspected from e to e. In other words, when the object to be inspected is in the position of
This is because the distance between the rays at this position) is dense.

In the first and second embodiments, the correction devices 7-1 to 7-3
20.22a to 22g are provided, it is possible to keep the variation in radiation intensity of each radiation source 1a to le and 20a to 20g within the permissible value, and furthermore, each radiation source 1-
It is not necessary that the radiation intensities of 1 to 1-320 and 20a to 20g be the same.

Note that the present invention is not limited to the first and second embodiments described above. For example, it can also be applied to second generation OCT scanners. FIG. 5 is a configuration diagram when applied to this second generation OCT scanner. The radiation source group 30 is
It is composed of radiation sources 30-1 to 30-5, and is provided so that the radiation from these radiation sources 3θ-1 to 30-5 is radiated from a virtual focus δa. 40 is a group of radiation detectors, 40-J to 40-5 are radiation detectors, and 41-1 to 4/5 are correction devices. Also 42.4
3 is a collimator. In the inspection of the inspected object 4,
The object to be inspected 4 is moved (traverse operation) in the direction of the arrow (B), for example, and radiation is emitted and detected during each traverse operation to obtain data. After completing the traverse operation in one direction, the inspected object 4 is rotated by a predetermined angle and then traversed in the direction of arrow (C). Collect data while operating in this way. therefore,
This device can also be applied to second-generation OCT scanners and can obtain cross-sectional images with excellent spatial resolution.

Moreover, the radiation intensity can be corrected without using the correction devices 7a to 7e, 22a to 22g, and the radiation intensity can be corrected by using the radiation detectors 5&~5c, 21a.
This may be done by adjusting the sensitivity to ~21 g.

Furthermore, each radiation source 1a-le, 20a-20g has one focal point 0
It is not necessary to arrange them at the same interval from the radiation detectors 10a, and it is sufficient to arrange them so that the amount of radiation incident on the radiation detectors 5a to 5e and 21a to 21g is the same.

In the above embodiment, radiation sources 1a to 1 s t 20h to
20g and radiation detectors 5&~5e, 21'&~21g are made to correspond, but the number of radiation ports formed by housing adjacent radiation sources or multiple radiation sources in the same radiation source The same number of radiation detectors may be provided.

〔Effect of the invention〕

According to the present invention, information on the object to be inspected is obtained by detecting radiation from a radiation source group in which a plurality of radiation sources are arranged so that radiation is emitted from one focal point. It is possible to provide a radiation measurement device in which the intensity of the radiation source can be increased without increasing the size, and the transmission ability as well as the spatial resolution can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining radiation emission due to differences in focus size, and FIG. 2 is a configuration showing a first embodiment of a radiation measuring device according to the present invention.
;+/-%ASu TateQ If! 71 If ;++a
A specific structural diagram of the daytime M-t II meter, FIG. 4 is a block diagram showing a second embodiment of the present device, and FIG. 5 is a block diagram showing a modification of the present device. DESCRIPTION OF SYMBOLS 1... Radiation source group, 1-1 to 1-320... Radiation source, 3... Collimator, 4... Inspection object, 5...
Radiation detector group, 5-1 to 5-320... Radiation detector, 6... 1J meter, 7-1 to 7-320...
Correction device, 1o...Data collection unit, 11...Image reconstruction unit, 12...Display control unit, 13...Monitor television, 2□0...Radiation source group %' 2
0 a to 20 g - Radiation source, 2 - Radiation detector group, 2ja to 21g - Radiation detector. Applicant's agent Patent attorney Takehiko Suzue Figure 3 ('a) (b) Figure 5

Claims (1)

[Claims] A radiation source group in which a plurality of radiation sources are arranged so that the radiation emitted from these radiation sources is emitted from one focal point in a fan shape, and a radiation source group is provided opposite to this radiation source group via a test object. and a plurality of radiation detectors configured to detect radiation transmitted through the object to be inspected from the radiation source group, and obtain information regarding the object to be measured based on detection signals from the plurality of radiation detectors. Radiation measurement device.