KR101684780B1

KR101684780B1 - Variable pin-hole collimator, radiation imaging device and radiation detecting device using the same

Info

Publication number: KR101684780B1
Application number: KR1020150061557A
Authority: KR
Inventors: 이학재; 배승빈; 이기성
Original assignee: 고려대학교 산학협력단
Priority date: 2015-04-30
Filing date: 2015-04-30
Publication date: 2016-12-08
Also published as: KR20160129421A; WO2016175360A1

Abstract

The present invention relates to a variable pinhole collimator device, and a radiation imaging device and a radiation sensing device using the same. A variable pinhole collimator according to the present invention includes: a plurality of pinhole plates each having a plurality of through holes having diameters different from each other formed on a surface of the plate, the lens plates being stacked in a direction of incidence of radiation; And a plurality of driving modules for moving each of the pinhole plates so that one of the plurality of through holes formed in each of the pinhole plates is selectively positioned in the overlapping region to form a pinhole in the overlapping region. Accordingly, it is possible to change the characteristics of the pinhole collimator such as the angle of view or the hole diameter of the pinhole collimator applied to the radiation imaging apparatus such as the gamma camera or the single photon emission computed tomography apparatus, but it can be implemented with a thinner thickness.

Description

TECHNICAL FIELD [0001] The present invention relates to a variable pinhole collimator, a variable pinhole collimator, and a radiographic imaging apparatus and a radiation detection apparatus using the same.

The present invention relates to a variable pinhole collimator and a radiation imaging apparatus and a radiation sensing apparatus using the same. More particularly, the present invention relates to a variable pinhole collimator apparatus and a radiation imaging apparatus using the variable pinhole collimator apparatus, The present invention relates to a variable pinhole collimator apparatus for determining a passage region and a direction of radiation, and a radiation imaging apparatus and a radiation detection apparatus using the same.

Radiographic imaging devices are devices that acquire images using radioactive isotopes and are widely used in the fields of nuclear medicine diagnosis and non-destructive examination.

BACKGROUND ART Radiographic imaging devices used in the field of nuclear medicine diagnosis, for example, gamma-ray cameras using a gamma ray or single photon emission computed tomography apparatuses, can be used for other diagnostic devices for providing structural information of the human body such as magnetic resonance imaging (MRI) Unlike diagnostic devices, functional information of the human body is provided using radioactive drugs.

Fig. 1 is a diagram showing the configuration of a conventional gamma camera 1. Fig. The general gamma camera 1 includes a collimator 10 and a radiation detector 20 for sensing radiation passing through the collimator 10. The collimator 10 is a color gamut camera.

The collimator 10 functions as a sighting device for passing only the gamma rays in a specific direction among the gamma rays emitted from the in vivo tracer and blocking the gamma rays coming from the other direction. That is, the collimator 10 geometrically restricts the gamma rays emitted from the living body region, so that only the gamma rays emitted from the necessary sites are incident on the radiation detection unit 20.

The collimator 10 shown in FIGS. 1 and 2 shows an example of a multiple pinhole collimator (or a parallel-hole collimator) in which a plurality of holes are formed, and FIG. 3 shows an example of a pinhole collimator Fig.

1, the radiation detecting unit 20 may include a scintillator 21, a light guide unit 22, and a light pipe 23. The gamma ray passing through the collimator 10 is incident on the scintillator 21.

The gamma rays that have passed through the collimator 10 and reacted with the scintillator 21 are converted into low energy electromagnetic waves of a shape that can be easily detected by the scintillator 21 and are transmitted through the light guide unit 22 to the opto- And the detected position or energy is stored in the computer 70 to acquire an image.

The single photon emission computed tomography apparatus using the principle of the gamma ray camera as described above was invented in 1976. It was first developed by W. I. Keys, 1979. Brain-specific devices were developed by R. J. Jaszczak.

The single photon emission computed tomography apparatus is similar to the operation principle of the gamma camera 1. The single photon emission computed tomography apparatus is similar to the operation principle of the gamma camera 1 in that a single photon such as a gamma ray emitting radiopharmaceutical is injected into the living body T, As shown in Fig. 2, is measured at various angles by a gamma ray camera installed in a gantry (not shown) rotating around the living body, and the detected signal is acquired by an image reconstruction algorithm.

Therefore, the collimator 10 and the gamma ray detection unit 20 are applied to the single photon emission computed tomography apparatus in the same manner as the gamma camera 1.

3 is a view for explaining the principle of the gamma ray imaging apparatus 1a using the conventional pinhole collimator 10a applied to the gamma camera 1 or the single photon emission computed tomography apparatus.

Referring to FIG. 3, the pinhole collimator 10a is configured to have a predetermined angle of view (Acceptance angle,?) And a hole diameter (1). As a result, only the gamma rays incident within the range of the angle of view are formed to pass through the holes. As a result, the gamma rays are selectively passed through the multi-pinhole collimator 10 and other geometries.

The resolution and sensitivity of the gamma ray imaging apparatus 1a using the pinhole collimator 10a are determined by the angle of view and the diameter 1 of the pinhole collimator 10a and the distance D1 between the object to be measured and the collimator, And the distance D2 between the gamma ray detecting portion 20a.

However, in the case of the conventional pinhole collimator 10a, the angle of view? And the hole diameter 1 are fixed, and the resolution and sensitivity of the pinhole collimator 10a deteriorate depending on the position and size of the region of interest.

For example, it is possible to detect gamma rays emitted from a wider area as the angle of view is wider. However, as shown in FIG. 3, since a region of interest (ROI) such as a lesion is located inside the living body T If the pinhole collimator 10a having the angle of view capable of photographing the entire region of the living body T is used, the resolution of the lesion as the region of interest is relatively low.

Particularly, in the case of a single-photon emission computed tomography apparatus, the periphery of the living body is photographed while being rotated. When the pinhole collimator 10a having a fixed angle of view? Is used, since the position of the lesion is not fixed for each patient, The pinhole collimator 10a having the angle of view? Capable of shooting the entirety is used.

4 (a), the pinhole collimator 10a and the gamma ray detecting unit 20a are rotated in a state of being spaced apart from the living body by a predetermined distance in accordance with the angle of view. In this case, the lesion L, The distance between the pinhole collimator 10a and the pinhole collimator 10a changes. In the case of the image obtained from the lesion L, the resolution of the actual lesion L must be relatively low.

In order to solve such a disadvantage, after replacing the pinhole collimator 10a having the angle of view (θ) suitable for the position of the lesion L in recent years, as shown in FIG. 4 (b) (L) is measured in accordance with the angle of view (?).

However, in the case of the method shown in FIG. 4 (b), the distance between the lesion L and the pinhole collimator 10a, which is an area of interest, becomes farther away and the sensitivity of the image decreases. As a result, There is a disadvantage that the radiation material must be injected.

In order to solve the above problems, a pinhole collimator capable of adjusting the angle of view has been proposed in the 'Variable Pinhole Type Collimator Apparatus and Radiation Imaging Apparatus Using the Same' disclosed in Korean Patent Publication No. 10-1364339 filed by the present applicant have.

However, in the case of the pinhole collimator disclosed in Korean Patent Publication, a plurality of diaphragms are stacked to adjust the angle of view or the direction of the pinhole. In order to configure one diaphragm, a plurality of plates must be used, There is a problem that the number of plates increases by the product of the number of diaphragms constituting the pinhole collimator and the number of plates constituting one diaphragm, thereby increasing the thickness of the pinhole collimator.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a pinhole collimator, which is applied to a radiation imaging apparatus such as a gamma camera or a single photon emission computed tomography The present invention provides a variable pinhole collimator capable of realizing a thinner thickness, and a radiographic imaging apparatus and a radiation sensing apparatus using the same.

According to the present invention, there is provided a variable pinhole collimator, comprising: a plurality of pinhole plates each having a plurality of through-holes each having a different diameter on a surface of the plate, And a plurality of drive modules for moving each of the pinhole plates so that one of the plurality of through holes formed in each of the pinhole plates is selectively positioned in the overlapping region to form a pinhole in the overlapping region. This is accomplished by a pinhole collimator.

Here, the plurality of through-holes formed in one pinhole plate are arranged along the longitudinal direction of the pinhole plate; The driving module may linearly move the pinhole plate in the longitudinal direction such that any one of the plurality of through holes formed in the pinhole plate is located in the overlapping area.

Further, the plurality of pinhole plates are arranged radially about the overlapping region; The through-holes formed in each of the pinhole plates may be concentrated in the overlapping region to form the pinhole or be radially spaced from the overlapping region in accordance with the linear movement of the pinhole plate.

Each of the drive modules rotates the pinhole plate around a rotation axis of the pinhole plate to position any one of the plurality of through holes in the overlap area. The plurality of through-holes may be formed along the circumferential direction about the rotation axis so as to be selectively located in the overlap area in accordance with the rotation of the pinhole plate.

Here, the plurality of through-holes may be formed in the pinhole plate such that the centers thereof are located within the same radius from the center of the rotation axis.

The plurality of pinhole plates may be arranged such that the centers of the through holes pass through the centers of the overlapping regions as the pinhole plate rotates.

The plurality of pinhole plates may be laminated such that the rotation axis of the pinhole plate is radially centered on the overlapping region.

The through holes may be arranged in order of diameter.

According to another aspect of the present invention, there is provided a radiation imaging apparatus comprising: the variable pinhole collimator; A radiation detector for detecting radiation passing through the pinhole of the variable pinhole collimator; A radiation image processor for imaging the radiation detected by the radiation detector; And a controller for controlling each of the drive modules of the variable pinhole collimator so that the angle of view of the pinhole of the variable pinhole collimator is adjusted so as to be focused on the measurement target emitting the radiation.

Wherein the variable pinhole collimator further comprises a gantry for rotating the radiation detection unit around the measurement object; The control unit may adjust the pinhole of the variable pinhole collimator to focus on the measurement object based on a change in distance between the measurement object and the variable pinhole collimator as the variable pinhole collimator rotates around the measurement object.

The apparatus may further include an interval adjustment module for moving any one of the variable pinhole collimator and the radiation detector so that the interval between the variable pinhole collimator and the radiation detector is adjusted. The control unit may control the interval adjusting module so that the interval between the variable pinhole collimator and the radiation detecting unit is adjusted in synchronization with the angle of view of the pinhole of the variable pinhole collimator.

The measurement object includes a lesion located in the living body; The distance between the object to be measured and the variable pinhole collimator can be changed when the variable pinhole collimator and the radiation detection unit are rotated around the human body according to the position of the living body in the lesion.

The controller may control each drive module of the variable pinhole collimator so that the diameter of the pinhole is adjusted based on the distance between the measurement object and the variable pinhole collimator.

According to another aspect of the present invention, the above object is also achieved by a radioactive sensing apparatus to which the variable pinhole collimator is applied.

According to the present invention, it is possible to change the characteristics of the pinhole collimator such as the angle of view or the hole diameter of a pinhole collimator applied to a radiation imaging apparatus such as a gamma camera or a single photon emission computed tomography apparatus, A variable pinhole collimator which can be implemented with a thickness and a radiation imaging apparatus using the same.

In addition, since the variable pinhole collimator is applied to a single photon emission computed tomography apparatus, it is possible to acquire a shape having a significantly higher resolution than a conventional pinhole collimator when photographing only a region of interest such as a lesion.

By applying the variable pinhole collimator to the single photon emission computed tomography apparatus, even if the distance from the lesion within the living body changes, the image can be photographed at the nearest position to the lesion while focusing on the plane of the lesion. It is possible to minimize the amount of the radiation material.

1 is a view showing a configuration of a conventional gamma camera,
2 is a view for explaining the operation principle of a single photon emission computed tomography apparatus,
3 is a view for explaining the principle of a gamma ray imaging apparatus using a conventional pinhole collimator,
4 is a view showing an example of operation of a single photon emission computed tomography apparatus to which a conventional pinhole collimator is applied,
5 and 6 are views for explaining a configuration of a variable pinhole collimator according to a first embodiment of the present invention,
7 is a view illustrating an example of stacking a pinhole forming module of a variable pinhole collimator according to a first embodiment of the present invention,
8 is a cross-sectional view taken along line VIII-VIII of FIG. 7,
9 is a view for explaining a pinhole forming module of a variable pinhole collimator according to a second embodiment of the present invention,
10 is a view showing a configuration of a radiation imaging apparatus to which a variable pinhole collimator according to the present invention is applied,
11 is a view for explaining an operation example of a radiation imaging apparatus to which a variable pinhole collimator according to the present invention is applied,
12 is a view for explaining an effect of a radiation imaging apparatus to which a variable pinhole collimator according to the present invention is applied,
13 is a view showing an example in which the variable pinhole collimator according to the present invention is applied to a radiation detection apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The variable pinhole collimator 100 apparatus according to the present invention is applied to a radiation imaging apparatus such as a gamma camera or a single photon emission computerized tomography apparatus. Although the present invention is applied to a nuclear magnetic resonance imaging apparatus, it is needless to say that a variable pinhole (PH) type collimator apparatus according to the present invention is also applicable to a radiation imaging apparatus or a radioactivity examination apparatus for non-destructive examination using gamma rays.

[First Embodiment]

5 and 6 are views for explaining the configuration of the variable pinhole collimator 100 according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view of a variable pinhole collimator 100 according to the first embodiment of the present invention. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7; FIG.

5 to 8, the variable pinhole collimator 100 according to the first embodiment of the present invention includes a plurality of pinhole plates 111 and a plurality of driving modules 120. [

The plurality of pinhole (PH) collimators are stacked in the incident direction of the radiation to constitute the pinhole forming module 110 for forming the pinhole PH. Here, as shown in FIG. 7, each of the pinhole plates 111 is formed with a plurality of through holes 111a, 111a, 111a and 111n having mutually different diameters.

Each driving module 120 moves the pinhole plate 111 to form a pinhole PH in the overlap area PFA. More specifically, each of the driving modules 120 is mounted on the pinhole plate 111 such that one of the plurality of through holes 111a, 111a, 111a, and 111n formed in the pinhole plate 111 is selectively positioned in the overlapping area PFA 111 are moved to form a pinhole PH in the overlap area PFA.

5 and 7, the pinhole plate 111 is provided in the form of a bar, and a plurality of through holes 111a, 111a, 111a, and 111n are formed in the shape of a bar, As shown in FIG. Here, the plurality of through holes 111a, 111a, 111a, and 111n formed in one pinhole plate 111 are formed in the order of their diameters.

5, the driving module 120 may be configured such that one of the plurality of through holes 111a, 111a, 111a, and 111n formed in the pinhole plate 111 is positioned in the overlap area PFA, The pinhole PH is formed in the overlapping area PFA by linearly moving the plate 111 in the longitudinal direction thereof. In the present invention, the drive module 120 is provided in the form of a drive motor 121 and a linear guide 122 for linear movement of the pinhole plate 111. That is, it is assumed that the linear guide 122 having an outer diameter threaded along with the rotation of the drive motor 121 is arranged to linearly move the pinhole plate 111 by rotation.

In the present invention, the pinhole plate 111 is stacked so that the overlapping area PFA is radially arranged at the center C1 as shown in Figs. 5 and 7. The through holes 111a, 111a, 111a and 111n formed in the respective pinhole plates 111 are collapsed into the overlapping area PFA in accordance with the linear movement of the pinhole plate 111 The pinhole PH is formed or radially spaced apart from the overlapping area PFA to deviate from the overlapping area PFA and the other through holes 111a, 111a, 111a and 111n can form the pinhole PH.

According to the above arrangement, any one of the plurality of through-holes 111a, 111a, 111a and 111n formed in each of the plurality of pinhole plates 111 stacked in the direction of the radiation is arranged in the overlapping area PFA, The angle of view of the pinhole PH formed in the overlap area PFA and the hole diameter 1 of the pinhole PH can be adjusted.

8, the hole diameter (l) of the pinhole (PH) to be formed in the through holes (111a, 111a, 111a, 111n) of the pinhole plate (111) The through holes 111a, 111a, 111a, and 111n having diameters corresponding to the through holes 111 are arranged in the overlapping area PFA. 8 shows an example in which two pinhole plates 111 form a hole diameter l.

Through holes 111a (111a), 111a (111a), and 111n (111a) having a larger diameter sequentially than the through holes (111a, 111a, 111a, 111n) having a hole diameter 1 in the upper and lower directions of the pinhole plate 111 having the hole diameter The through holes 111a, 111a, 111a and 111n of the remaining pinhole plates 111 are arranged in the overlap area PFA so that the pinholes PH Is determined.

At this time, as the difference in diameter between the adjacent through holes 111a, 111a, 111a and 111n in the stacking direction is increased, the angle of view? Formed becomes larger and the diameter of the adjacent through holes 111a, 111a, 111a and 111n The smaller the difference is, the smaller the angle of view [theta] formed becomes.

The through holes 111a, 111a, 111a and 111n to be arranged in the overlapping area PFA of the through holes 111a, 111a, 111a and 111n formed in the respective pinhole plates 111 are connected to the driving module The angle of view θ and the hole diameter 1 of the pinhole PH formed on the variable pinhole collimator 100 according to the present invention can be changed.

[Second Embodiment]

Hereinafter, the pinhole forming module 210 of the variable pinhole collimator 100 according to the second embodiment of the present invention will be described in detail with reference to FIG.

The pinhole forming module 210 of the variable pinhole collimator 100 according to the second embodiment of the present invention is an example in which a disk-shaped pinhole plate 211 is laminated in the direction of incidence of radiation.

9, the driving module (not shown) rotates the pinhole plate 211 around the rotation axis C2 of the pinhole plate 211 to form the through holes 211a, 211a, 211a, and 211n, Is placed in the overlap area PFA.

The plurality of through holes 211a, 211a, 211a and 211n are formed in the circumferential direction about the rotation axis C2 of the pinhole plate 211, (PFA) in accordance with the rotation of the substrate (211).

The plurality of through holes 211a, 211a, 211a and 211n formed in one pinhole plate 211 are formed such that their centers are located within the same radius around the rotation axis C2 of the pinhole plate 211 . The centers of the through holes 211a, 211a, 211a, and 211n located in the overlapping area PFA when the pinhole plate 211 rotates about the rotation axis C2 are aligned with the center of the pinhole The pinhole PH having a constant angle of view? Can be formed by the plurality of through holes 211a, 211a, 211a and 211n as shown in Fig. .

The plurality of pinhole plates 211 are arranged so that the centers of their through holes 211a, 211a, 211a and 211n can pass through the center C1 of the overlap region PFA in accordance with each rotation. That is, when all of the through holes 211a, 211a, 211a, and 211n formed in the pinhole plate 211 stacked in the direction of incidence of the radiation pass through the overlap area PFA, the pinhole PH The center of the through hole 211a, 211a, 211a, and 211n can be passed through the center C1.

In the present invention, the pinhole plate 211 is laminated such that the rotation axis C2 of each pinhole plate 211 is radially positioned at the center C1 of the overlapping area PFA. All the through holes 211a The rotational axis C2 of the pinhole plate 211 is positioned at the same radius from the center C1 of the pinhole PH so that the center of the pinhole PHA 211a, 211a, 211a, 211n can pass through the center C1 of the pinhole PH. .

Through the variable pinhole collimator 100 according to the second embodiment of the present invention, the adjustment of the angle of view? And the hole diameter l of the pinhole PH formed in the overlapping area PFA .

[Radiographic Imaging Device]

Hereinafter, a radiation imaging apparatus according to the present invention will be described in detail with reference to FIGS. 10 and 11. FIG. Here, in the radiation imaging apparatus according to the present invention, the variable pinhole collimator 100 according to the first embodiment described above is applied.

As shown in FIG. 10, the radiation imaging apparatus according to the present invention includes a variable pinhole collimator 100, a radiation detector 320, an image processor, and a controller 310.

The variable pinhole collimator 100 includes a pinhole forming module 110 composed of a plurality of driving modules 120 and a plurality of pinhole plates 111 that are moved or rotated by the respective driving modules 120 . Here, the variable pinhole collimator 100 has been described above, and a detailed description thereof will be omitted.

The radiation detector 320 detects a radiation, that is, a gamma ray, which has passed through the pinhole PH formed by the variable pinhole collimator 100. The configuration of the radiation detector 320 according to the present invention may have various known types capable of detecting radiation.

The radiation image processing unit 350 images the radiation detected by the radiation detecting unit 320. In the case where the radiation imaging apparatus according to the present invention is provided in the form of a single photon emission computerized tomography apparatus, the radiation image processing unit 350 uses an image reconstruction algorithm using radiation detected at various angles according to the rotation of the gantry 340 Thereby forming a tomographic image.

The control unit 310 controls the variable pinhole collimator 100 so that the pinhole PH formed by the variable pinhole collimator 100 is focused on the lesion L in the measurement target, for example, the living body T emitting the radiation. (?). The controller 310 controls the driving module 120 of the variable pinhole collimator 100 to adjust the angle of view θ of the pinhole PH formed by the pinhole forming module 110.

When the radiation imaging apparatus according to the present invention is provided in the form of a single photon emission computerized tomography apparatus, the radiation imaging apparatus includes a variable pinhole collimator 100 and a gantry 340 for rotating the radiation detection unit 320 toward the measurement subject. . &Lt; / RTI >

The control unit 310 controls the variable pinhole collimator 100 so that the variable pinhole collimator 100 is focused on the object to be measured based on the change in distance between the object and the variable pinhole collimator 100 as the object rotates around the object to be measured. (PH) can be adjusted.

The radiation imaging apparatus according to the present invention further includes an interval adjusting module 330 for moving any one of the variable pinhole collimator 100 and the radiation detecting unit 320 so that the interval between the variable pinhole collimator 100 and the radiation detecting unit 320 is adjusted, ). In the present invention, the distance between the two members can be adjusted by the distance measuring module by allowing the radiation detecting portion 320 to approach or separate from the variable pinhole collimator 100.

The control unit 310 controls the interval adjusting module 330 to adjust the interval between the variable pinhole collimator 100 and the radiation detecting unit 320 in synchronization with the angle of view of the pinhole PH of the variable pinhole collimator 100, Can be controlled.

Hereinafter, a driving method of a radiation imaging apparatus according to the present invention will be described with reference to FIG. Here, it is assumed that the subject to be photographed by the radiation imaging apparatus according to the present invention is a lesion (L) located in the living body (T). At this time, the variable pinhole collimator 100 and the radiation detecting unit 320 rotate around the living body T by the gantry 340 to acquire a radiological image. As shown in FIG. 11, The distance between the lesion L to be measured and the variable pinhole collimator 100 changes when the variable pinhole collimator 100 and the radiation detector 320 are rotated around the living body T according to the position of the variable pinhole collimator 100. [

11, a variable pinhole collimator 100 and an interval adjusting module 330 (not shown) are used as a region of interest, with the lesion L as a region of interest, ).

11, when the variable pinhole collimator 100 and the radiation detector 320 are rotated around the living body T by the gantry 340, the variable pinhole collimator 100 and the lesion L ) Is changed. The control unit 310 controls the driving module 120 such that the pinhole PH formed by the variable pinhole collimator 100 is focused on the lesion L. [

11, when the variable pinhole collimator 100 is positioned on the left side of the living body T, the positions of the variable pinhole collimator 100 and the lesion L are shifted to the left side of the living body T It becomes close. The control unit 310 controls the drive module 120 so that the angle of view of the pinhole PH formed by the variable pinhole collimator 100 is widened so that the pinhole PH of the variable pinhole collimator 100 is focused on the surface of the lens. .

On the other hand, when the variable pinhole collimator 100 is positioned on the right side of the living body T, the position of the variable L and the variable pinhole collimator 100 are distant from each other. When the variable angle pinhole collimator 100 maintains the angle of view The driving module 120 is controlled so that the angle of view? Of the variable pinhole collimator 100 is reduced so as to be focused on the lesion L as a wider area is photographed without focusing on the lesion surface.

11, when the angle of view of the pinhole PH of the variable pinhole collimator 100 is changed, the control unit 310 controls the variable pinhole collimator 100 and the radiation detecting unit 320, By adjusting the interval, a constant enlargement ratio is maintained, which enables clearer and more accurate image acquisition.

The position and size of the lesion L in the living body T are preset through the ROI setting unit 360 so that the variable pinhole collimator 100 and the lesion L Can be calculated, and the angle of view? At the position can be automatically determined. For example, in the case of cancer occurring in a human body, the position of the lesion L can be normally confirmed, and the ROI can be set through the ROI setting unit 360.

According to the above configuration, measurement can be performed while adjusting the angle of view (?) Of the pinhole (PH) of the variable pinhole collimator (100), so that only the lesion (L) It becomes possible to acquire a higher resolution image for the lesion L. [

In addition, the variable pinhole collimator 100 can be photographed at a position as close as possible to the lesion L, which is an area of interest, at each rotation position, so that the sensitivity of the variable pinhole collimator 100 can be minimized do.

This can be confirmed through simulation results as shown in FIG. 12 (a) shows an image obtained by a method shown in FIG. 4 (a) using a fixed pinhole (PH) collimator, and FIG. 12 (b) shows an image obtained by using a fixed pinhole (PH) collimator 11 (c) shows an image obtained by the method as shown in Fig. 11 (b) by using the variable pinhole collimator 100 according to the present invention, and Fig. 11 . As shown in FIG. 12, it can be seen that the resolution of the region of interest obtained using the variable pinhole collimator 100 according to the present invention is remarkably high.

In the above-described embodiment, the variable pinhole collimator 100 is applied to a radiation imaging apparatus such as a single photon emission computed tomography apparatus. It is needless to say that the variable pinhole collimator 100 according to the present invention can also be applied to a radiation detection apparatus. For example, when the variable pinhole collimator 100 according to the present invention is applied to a detection camera for detecting radiation leakage in a nuclear power plant, in general imaging, the angle of view (?) Is widened to detect a wider area, The pinhole PH of the variable pinhole collimator 100 can be controlled so that the pinhole PH is focused on the corresponding region.

More specifically, referring to Fig. 13, as shown in Figs. 13 (a) and 13 (b), the angle of view? Can be broadened as much as possible and only the presence or absence of the radiation source can be grasped. FIG. 13A shows an example in which the hole diameter 1 is widened to realize low resolution, and FIG. 13B shows an example in which the hole diameter 1 is narrowed to realize high resolution.

13 (a) and 13 (b), a wide range is screened to obtain a rough position of the source. When the radiation is leaked and radiation is detected at a specific position, As shown in the figure, the angle of view? Is narrowed so as to be focused to the corresponding position, so that the position can be detected more focusedly.

In addition, in the above-described embodiment, the measurement target is defined as a living body (T), and this is defined as a concept including both a human body and an animal.

Although several embodiments of the present invention have been shown and described, those skilled in the art will readily appreciate that many modifications may be made without departing from the spirit or scope of the invention . The scope of the invention will be determined by the appended claims and their equivalents.

100: Variable pinhole collimator 110, 210: Pinhole forming module
111, 211: pinhole plate 112: drive module
111a, 111b, 111c, 111n, 211a, 211b, 211c, 211n:
310: controller 320: radiation detector
330: Spacing module 340: Gantry
350: Radiation image processing unit 360: ROI setting unit
PH: Pinhole PFA: overlap area

Claims

In the variable pinhole collimator,
A plurality of pinhole plates each having a plurality of through holes having diameters different from each other formed on each of the plate surfaces, the plurality of pinhole plates being laminated in the direction of incidence of radiation;
And a plurality of drive modules for moving each of the pinhole plates so that one of the plurality of through holes formed in each of the pinhole plates is selectively positioned in the overlapping region to form a pinhole in the overlapping region. Pinhole collimator.

The method according to claim 1,
A plurality of the through-holes formed in one pinhole plate are arranged along the longitudinal direction of the pinhole plate;
Wherein the drive module linearly moves the pinhole plate in the longitudinal direction so that any one of the plurality of through holes formed in the pinhole plate is located in the overlapping region.

3. The method of claim 2,
A plurality of said pinhole plates are radially disposed about said overlapping region;
Wherein the through holes formed in each of the pinhole plates are concentrated in the overlapping region in accordance with the linear movement of the pinhole plate to form the pinhole or to be radially spaced from the overlapping region.

The method according to claim 1,
Each of the driving modules rotates the pinhole plate about the rotation axis of the pinhole plate to position any one of the plurality of through holes in the overlapping area;
Wherein the plurality of through-holes are formed along the circumferential direction around the rotation axis so as to be selectively positioned in the overlapping area according to rotation of the pinhole plate.

5. The method of claim 4,
And the plurality of through-holes are formed in the pinhole plate such that the centers thereof are located within the same radius from the center of the rotation axis.

6. The method of claim 5,
And a plurality of the pinhole plates are disposed such that centers of the through holes pass through the centers of the overlapping regions in accordance with rotation of the pinhole plate.

6. The method of claim 5,
And the plurality of pinhole plates are laminated so that the rotation axis of the pinhole plate is radially centered on the overlapping region.

The method according to claim 1,
And the through holes are arranged in the order of the diameter of the pinholes.

In a radiation imaging apparatus,
A variable pinhole collimator according to any one of claims 1 to 8;
A radiation detector for detecting radiation passing through the pinhole of the variable pinhole collimator;
A radiation image processor for imaging the radiation detected by the radiation detector;
And a control unit for controlling each drive module of the variable pinhole collimator so that an angle of view of the pinhole of the variable pinhole collimator is adjusted so as to be focused on a measurement target emitting radiation.

10. The method of claim 9,
Further comprising a variable pinhole collimator and a gantry for rotating the radiation detection unit around the measurement target;
Wherein the controller adjusts the pinhole of the variable pinhole collimator to focus on the measurement object based on a change in distance between the measurement object and the variable pinhole collimator as the variable pinhole collimator rotates around the measurement object Radiation imaging device.

11. The method of claim 10,
Further comprising an interval adjustment module for moving any one of the variable pinhole collimator and the radiation detector so that the interval between the variable pinhole collimator and the radiation detector is adjusted;
Wherein the control unit controls the interval adjusting module so that the interval between the variable pinhole collimator and the radiation detecting unit is adjusted in synchronism with the angle of view of the pinhole of the variable pinhole collimator.

12. The method of claim 11,
The measurement object includes a lesion located in the living body;
Wherein the distance between the object to be measured and the variable pinhole collimator changes when the variable pinhole collimator and the radiation detector rotate around the human body according to a position of the inside of the lesion.

11. The method of claim 10,
Wherein the control unit controls each drive module of the variable pinhole collimator so that the diameter of the pinhole is adjusted based on a distance between the measurement object and the variable pinhole collimator.

A radiation detection apparatus to which a variable pinhole collimator according to any one of claims 1 to 8 is applied.