JPH0894760A - Radiation detector inserted into tube - Google Patents

Abstract

PURPOSE: To obtain a radiation detector being inserted into a tube in order to detect radiation by introducing a light emitted from a scintillator efficiently, with no attenuation, to a photoelectric converter. CONSTITUTION: A radiation probe 1 comprises a part 2 to be inserted into a tube, and a photoelectric converting part 3 disposed at an end of the inserting part 2. Two scintillators 4a, 4b are disposed at the forward end part 21 of the inserting part 2. The scintilallators 4a, 4b are connected optically with optical fibers 5a, 5b and the joint 22 is coated with a reflective member 6 before a shading/protecting tube 7 is applied over the optical fibers 5a, 5b. A shock absorbing member 8 is provided on the forward end side of the scintillator and covered with a shading coating 9 along with the scintillators 4a, 4b and the optical fibers 5a, 5b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation detecting device for intraluminal insertion for administering a radiolabeled tumor-accumulating substance to a living body and detecting radiation emitted from a tumor site for diagnosis.

[0002]

2. Description of the Related Art In order to detect a tumor in a body cavity, an endoscope is inserted into the body cavity to perform a macroscopic diagnosis. However, it is very difficult to detect a fine tumor or a tumor hidden under the mucous membrane from the viewpoint of spatial resolution even with a high degree of skill.

Therefore, a radioisotope accumulated in a tumor (hereinafter abbreviated as RI) is administered, radiation emitted from the tumor is detected by a radiation detector inserted into a body cavity, and an endoscope is used. A method of detecting a tumor that cannot be discerned by the naked eye is effective. However, since RI is actually scattered in tissues other than the target tumor, radiation may be incident on the radiation detector from these tissues as well, which may cause erroneous detection. Therefore, in order to perform effective detection, it is necessary to detect only the radiation emitted by the target tumor.

As a radiation detector for detecting the radiation emitted from this tumor, US Pat. No. 4,595,014 discloses an IMAGING PROBE using a scintillation detector inserted into a body cavity for use. In this radiation detector, in order to regulate the incident direction of the radiation incident on the scintillator to a fixed direction, a collimator made of a substance having a high radiation shielding ability such as tungsten is arranged around the scintillator.

A radiation detection apparatus using this scintillator is a scintillator which emits light when radiation enters, a photoelectric converter which converts the light emitted by this scintillator into an electric signal, and a light which is emitted by the scintillator to a photoelectric converter. It is composed of an optical fiber that emits light.

[0006]

However, since the light emitted from the scintillator when the radiation enters the radiation detecting device is extremely weak, the light emitted from the scintillator is guided to the photoelectric converter through the optical fiber. In doing so, the light emitted from the scintillator was attenuated and could not be efficiently guided to the photoelectric converter. Therefore, it takes a long time to detect the radiation, and the radiation cannot be detected efficiently.

The present invention has been made in view of the above circumstances, and a radiation detecting device for insertion into a lumen for efficiently guiding the light emitted from the scintillator to the photoelectric converter without being attenuated and detecting the radiation. Is intended to provide.

[0008]

DISCLOSURE OF THE INVENTION The radiation detecting apparatus for intraluminal insertion of the present invention is a scintillator which emits light when radiation enters and a light which is connected to this scintillator and transmits the light emitted by the scintillator to a photoelectric converter. A radiation detection device for intraluminal insertion, comprising: a fiber, wherein the maximum light emission wavelength of the scintillator is included in the light guide wavelength band of the optical fiber.

[0009]

According to this structure, since the light emission wavelength range of the light emitted by the scintillator is included in the light guide wavelength band of the optical fiber for guiding the light emitted by the scintillator, the light emitted by the scintillator can be suppressed from being attenuated, The light is efficiently guided through the optical fiber and reaches the photoelectric converter.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 relate to an embodiment of the present invention, FIG. 1 is a cross-sectional view showing a configuration of a radiation detecting apparatus for intraluminal insertion, and FIG. 2 is a diagram showing an operation of the radiation detecting apparatus for intraluminal insertion. .

As shown in FIG. 1 (a), a radiation detecting device for intraluminal insertion (hereinafter abbreviated as a radiation probe) 1 is a flexible and flexible insertion portion that can be inserted into a lumen such as a living body lumen. 2 and a photoelectric conversion unit 3 arranged at the proximal end of the insertion unit 2.

Two scintillators 4a and 4b are arranged at the distal end portion 21 of the insertion section 2, and optical fibers 5a and 5b are optically connected to these scintillators 4a and 4b, respectively. . In the joint 22 where the scintillators 4a and 4b and the optical fibers 5a and 5b are connected, the shape of the joint surface of the scintillators 4a and 4b is, for example, a semicircular shape as shown in FIG. , The shape of the joint surface of the optical fibers 5a and 5b connected to the scintillators 4a and 4b is also the scintillator 4a,
It has the same shape as 4b. The scintillator of this embodiment has four
Each of a and 4b is a semi-circular shape having a joint surface of a diameter of 8 mm and a height of 6 mm.

The outer surface of the joint portion 22 connecting the scintillators 4a and 4b and the optical fibers 5a and 5b is coated with a reflecting material 6 such as MgO (magnesium oxide), while the optical fibers 5a and 5b are covered. Is inserted in the tube 7 for light shielding and protection. Further, a shock absorbing cushioning material 8 is provided on the tip end side of the scintillator also as a retainer for preventing separation of the joint portion between the scintillators 4a and 4b and the optical fibers 5a and 5b. These buffer material 8, scintillators 4a and 4b, and optical fibers 5a and 5b
Are covered with a light-shielding coating 9 that shields light. A base 10 having a click portion 10a is provided at the proximal ends of the optical fibers 5a and 5b led out from the light-shielding coating 9.

The maximum emission wavelength of the light emitted from the scintillators 4a and 4b has a unique value depending on the type of scintillator. Therefore, when the scintillators 4a and 4b and the optical fibers 5a and 5b are built in the insertion portion 2 to configure the radiation probe 1, the maximum emission wavelength of the scintillators 4a and 4b is set in the light guide wavelength band of the optical fibers 5a and 5b. The optical fiber included in is used. For example, when BGO (Bi4Ge3O12 crystal) is used for the scintillators 4a and 4b, the maximum emission wavelength of this BGO is about 480n.
m, the optical fibers 5a and 5b used at this time
In addition, a material having a characteristic of efficiently guiding light in the wavelength range of 480 nm is used.

On the other hand, the photoelectric conversion unit 3 includes, for example, a photoelectric converter 31a such as a head-on type photomultiplier,
31b, an insulating member 32 disposed on the light-receiving surface side of the photoelectric converters 31a and 31b, for example, a transparent acrylic plate, and the insulating member 32 and the photoelectric converters 31a and 3b.
The shield case 33 is provided with a concave portion 33a into which the click portion 10a of the mouthpiece 10 that covers the 1b is fitted, and a light shielding case 34 that covers the shield case 33. The signal lines 35a and 35b extending from the photoelectric converters 31a and 31b are shielded by the shield case 3
3 and the light-shielding case 34 are provided to the outside, and connection connectors 36a and 36b, which are detachably connectable to the measuring device, are provided at the ends of the signal lines 35a and 35b.

Here, the insertion section 2 and the photoelectric conversion section 3
The connection with is explained. When the insertion section 2 and the photoelectric conversion section 3 are connected, the base 10 provided at the proximal end of the optical fibers 5a and 5b built into the insertion section 2 is provided with a shield case 33 that constitutes the photoelectric conversion section 3. Then, it is inserted into the opening formed in the light shielding case 34. Then, the proximal end faces of the optical fibers 5a and 5b face each other via the insulating member 32 whose end faces are arranged on the light receiving surface sides of the photoelectric converters 31a and 31b. At this time, the click portion 10a of the mouthpiece 10 provided on the optical fibers 5a and 5b is attached to the shield case 33.
It is fitted into the concave portion 33a formed in 1), positioned and fixed, and optically connected. The insertion section 2 and the photoelectric conversion section 3 are detachable by the click section 10 and the recess 33a.

The operation of the intraluminal insertion radiation detecting apparatus 1 constructed as described above will be described. As shown in FIG. 2, the radiation probe 1 is inserted into the body cavity 51 under ultrasonic observation. Then, when the radiation probe 1 reaches the vicinity of the observation site, the cavity wall is scanned by the tip of the radiation probe to detect the site where the radiation is emitted and the affected part 52.

Insertion part 2 tip part 2 of the radiation probe 1
When radiation is incident on the scintillators 4a and 4b provided in No. 1, light in the visible wavelength region is generated from the scintillators 4a and 4b. The light emitted from the scintillators 4a and 4b is transmitted through the optical fibers 5a and 5b to the photoelectric converters 31a,
The light is guided to the light receiving surface of 31b. Then, the electric signals are converted into electric signals by the photoelectric converters 31a and 31b, and the signal line 35
Through a, 35b and connectors 36a, 36b, a radiation counting device (not shown) is input to detect the radiation emitting portion of the subject.

As described above, when selecting an optical fiber which constitutes the radiation detecting device (radiation probe) for insertion into the lumen, the characteristic of the light guide wavelength band of the optical fiber is the maximum of the scintillator arranged in the radiation probe. Since the optical fiber including the emission wavelength is used, the light incident on the radiation and emitted by the scintillator can be efficiently guided in the optical fiber and guided to the light receiving surface of the photoelectric converter. As a result, the light emitted from the scintillator is guided to the photoelectric converter without being attenuated, and highly accurate radiation detection is performed in a short time.

Further, the shapes of the joint surfaces of the scintillator and the optical fiber are made to coincide with each other, and the outer surface of the joint portion of the scintillator and the optical fiber is coated with a reflecting material so that the light emitted from the scintillator is not leaked to the outside. The light emitted from the scintillator can be more efficiently guided to the photoelectric converter.

Further, by forming the scintillator in a semi-cylindrical shape, the two scintillators can be formed like a single cylinder by combining the flat surface portions of the two scintillators, so that the inside of a body cavity is thin. An insertion portion that can be easily inserted into the lumen can be formed.

Further, while the click portion is provided on the mouthpiece at the proximal end of the optical fiber and the photoelectric conversion portion is formed with a recess in the constituent shield case so as to be detachable, cleaning and disinfection of the insertion portion of the radiation probe is performed. Can be done easily.

Although BGO is used for the scintillators 4a and 4b of the radiation probe 1 in the above-described embodiment, the scintillator is not limited to BGO and ZnS is used.
(Ag), NaI (Tl), CsI (Tl), Lil
It may be (Eu), anthracene, a plastic scintillator, or the like.

Needless to say, the photoelectric converter may use a solid-state image sensor or the like instead of the head-on type photomultiplier.

Further, the shape of the scintillators 4a and 4b is not limited to the semi-cylindrical shape, and may be a shape such as a prism, a cylinder, a disc, a pyramid, a cone, or a half cone.

Further, the detachable structure of the joint between the optical fibers 5a and 5b and the photoelectric converter may be a screw type or a push-and-turn type other than the click type.

As shown in FIG. 3, when the radiation probe 1 is inserted endoscopically into the body cavity, the endoscope 6 is used.
The radiation probe 1 is inserted into the treatment tool insertion channel 62 provided inside the insertion portion 61 of 0, and the inner wall of the cavity is scanned with the radiation probe 1 while observing the inside of the body cavity with the endoscope 60.
Thereby, even if the affected part 52 is hidden under the mucosal layer of the inner wall of the cavity by performing an inspection with the radiation probe 1 through the treatment tool insertion channel 62 of the endoscope 60, and it is difficult to find it by an optical image, The affected area 52 can be detected by detecting the radiation. Further, as a method of combining the radiation probe 1 and the endoscope, the probe 1 may be placed along the side surface of the insertion portion of the endoscope and inserted into the body cavity. The cavities to be examined include the digestive system cavities such as the esophagus, stomach, and intestines, as well as the urethra, ureter, vagina, uterus, trachea, and blood vessels.

[Additional Notes] 1. In a radiation detection device for intraluminal insertion, which comprises a scintillator that emits light when radiation enters, and an optical fiber that is connected to this scintillator and that transmits the light emitted by the scintillator to a photoelectric converter, in a light guide wavelength band of the optical fiber. A radiation detection device for insertion into a lumen in which the maximum emission wavelength of the scintillator is included.

2. 2. The radiation detecting device for intraluminal insertion according to appendix 1, wherein the cross-sectional shape of the connection surface between the scintillator and the optical fiber is the same.

3. The radiation detecting device for intraluminal insertion according to appendix 2, wherein the cross-sectional shape of the connection surface between the scintillator and the optical fiber is a semicircular shape.

4. The radiation detection device for insertion into a lumen according to appendix 1, wherein the base provided at the proximal end of the optical fiber and the photoelectric conversion unit are detachable.

[0032]

As described above, it is possible to provide a radiation detecting device for insertion into a lumen which efficiently guides light emitted from a scintillator to a photoelectric converter without being attenuated and detects radiation. .

[Brief description of drawings]

1 and 2 relate to an embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the configuration of a radiation detection apparatus for insertion into a lumen.

FIG. 2 is a view showing an operation of a radiation detecting device for intraluminal insertion.

FIG. 3 is a diagram showing a state in which a radiation detecting device for intraluminal insertion is inserted into a body cavity through an endoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Radiation detection apparatus for intraluminal insertion 4a, 4b ... Scintillator 5a, 5b ... Optical fiber 31a, 31b ... Photoelectric converter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G02B 6/00

Claims (1)

[Claims] 1. A radiation detecting apparatus for intraluminal insertion, comprising: a scintillator that emits light when radiation enters; and an optical fiber that is connected to the scintillator and transmits the light emitted by the scintillator to a photoelectric converter. The maximum radiation wavelength of the scintillator is included in the light guide wavelength band of the radiation detection device for intraluminal insertion.