JPH10155730A - Tube for mri observation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform easy, sure and safe medical curing treatment while optical observation by means of an endoscope and diagnosis of tomographic images by means of an MRI are performed. SOLUTION: In a tube for MRI observation, the base part comprises a tubular member 1 formed of a non-magnetic material and an endoscope 4 can be passed through the inner cavity of the tubular member 1. A loop antenna 2 as an antenna for MRI is provided at the apex part of the tubular member 1 and a coaxial cable 3 is connected with this loop antenna 2 and is extended from this end part of the tubular member 1 and is connected electrically with an MRI apparatus. An opening part 5 is formed on the inside part of the loop antenna and communicates with the inner cavity and through this opening part 5, optical observation by means of the objective lens 7 of the endoscope 5 and medical curing treatment by means of a treating tool 9 projected from a channel opening part 8 can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MRI observation tube which is inserted into a body cavity together with an endoscope to obtain a diagnostic image of a living body by MRI.

[0002]

2. Description of the Related Art In recent years, non-invasive methods for diagnosing the human body using the nuclear magnetic resonance (hereinafter abbreviated as NMR) phenomenon have been developed. For example, in nuclear magnetic resonance imaging (hereinafter abbreviated as MRI) utilizing the NMR phenomenon, a human body is placed in a magnetic field, and a high frequency (magnetic field) of a predetermined frequency is applied.
A tomographic image of a human body is obtained by exciting a nucleus having a spin in the human body, detecting an NMR signal of a predetermined frequency from the excited nucleus, and processing the NMR signal with a computer. This MR
The tomographic image obtained by I is extremely useful for diagnosis of cancer and the like. That is, it is generally known that NMR signals obtained from cancer cells and normal cells have different relaxation times, and it is possible to diagnose whether or not cancer is present by measuring the relaxation times.

[0003] Conventionally, when an abnormal location is visually found during endoscopic observation, there has been a demand to determine to some extent whether or not the abnormal location is, for example, a malignant one. On the other hand, when the above-mentioned MRI is used in combination, there is a problem that it is difficult to associate a visually recognized portion with a tomographic image with a tomographic image.

[0004] In order to address the above problems, for example, an NMR coil is provided in a sliding tube having a hollow passage through which an endoscope insertion portion can be inserted as disclosed in Japanese Patent Application Laid-Open No. 3-228742. 64-49
No. 48 in the medical indwelling tube
A device provided with an antenna coil for MR measurement has been proposed. By inserting into a body cavity together with an endoscope using such a tube provided with an antenna for MRI observation, optical observation by the endoscope and diagnosis of a tomographic image by MRI are performed, and mucous membrane in the body cavity is performed. Detection and diagnosis of abnormal sites on the surface and deep under the mucosa are possible.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Laid-Open Publication No. Hei 3-2
In a conventional tube for MRI observation such as a sliding tube disclosed in Japanese Patent No. 28742, an optical image by an endoscope and M
In order to correlate with the tomographic image by RI, it is necessary to perform a complicated operation such as bending the insertion section of the endoscope in accordance with the position of the coil for NMR and directing the observation optical system at the distal end. It was not always easy to make the detection positions coincide. In addition, since treatment is not considered much only by detecting an abnormal site, it is difficult to directly access an affected part to perform treatment even if a submucosal condition can be diagnosed.

For example, in a sliding tube disclosed in Japanese Patent Application Laid-Open No. 3-228742, when a lesion is found under the mucosa using an NMR coil, even if a biopsy for a definitive diagnosis is to be performed, the distal end of the endoscope is required. Is located away from the NMR coil, and the mucosa
It is extremely difficult to perform a biopsy using a treatment tool through a channel of an endoscope because the biopsy is blocked by a coil for use.

The present invention has been made in view of these circumstances, and it is possible to perform an easy, reliable, and safe treatment while performing optical observation with an endoscope and diagnosing a tomographic image with MRI. It is intended to provide a possible MRI observation tube.

[0008]

An MRI observation tube according to the present invention comprises a tubular member for covering at least a part of an insertion portion of an endoscope, an MRI antenna built in the tubular member, and the tubular member. And an aperture that is capable of transmitting electromagnetic energy in a direction substantially coincident with the directional characteristics of the antenna.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a perspective view showing a configuration when an MRI observation tube and an endoscope are used in combination, and FIG. 2 is AA in FIG. 3 is a sectional view taken along the line BB of FIG. 1, FIG. 4 is an operation explanatory view for explaining the directivity of the MRI antenna, and FIG. 5 is an arrow view of FIG. 6 is an arrow view of FIG. 4 as viewed from the front in the direction D.

As shown in FIGS. 1 to 3, the MRI observation tube of the present embodiment has a base formed by a tubular member 1 formed of a non-magnetic material, and has an inner cavity of the tubular member 1. The mirror 4 can be inserted. The tubular member 1 is
It is composed of two tubes, an outer tube 1a and an inner tube 1b, which are made of a thin tube made of a polymer material such as a silicon tube or a resin tube, and are stacked. The tubular member 1 may be either a transparent member or an opaque member.

At the distal end of the tubular member 1, a loop antenna 2 formed in a substantially rectangular shape as an MRI antenna is provided. The loop antenna 2 is made of, for example, a thin-film conductor (eg, copper foil) formed on a flexible substrate.
It is disposed between the outer tube 1a and the inner tube 1b. A coaxial cable 3 is connected to the loop antenna 2, and the coaxial cable 3 is connected to the tubular member 1.
Is fixed to the inside of the tubular member 1 with an adhesive 6, extends from the proximal end of the tubular member 1, and is electrically connected to an MRI apparatus (not shown).

An inner portion of the loop antenna 2 is formed with an opening 5 and communicates with the lumen, so that the endoscope 4 inserted into the lumen of the tubular member 1 is exposed. In this embodiment, a side-view type endoscope 4 is used, and an end lens 4 of the endoscope 4 is provided with an objective lens 7 of an objective optical system and a channel opening 8. The treatment tool 9 inserted through the channel from the channel opening 8
Is projected so that a therapeutic treatment can be performed through the opening 5. Examples of the treatment tool 9 include a biopsy needle (biopsy forceps), a microwave therapy probe,
A high-frequency snare (loop electrode for an electric knife) or the like is used.

When performing diagnosis and treatment using the MRI observation tube configured as described above, first, the insertion portion of the endoscope 4 is inserted into the lumen of the tubular member 1 so that the tubular member 1 is inserted.
In a state where the endoscope 4 and the endoscope 4 are put together, they are introduced into a target site in the body cavity while observing with the endoscope 4. And
The position of the loop antenna 2 is confirmed while observing with an optical image obtained by the endoscope 4, and a high frequency magnetic field of a predetermined frequency is transmitted from the loop antenna 2 and an NMR signal of a predetermined frequency from a nucleus of a living body excited by excitation. Is again received by the loop antenna 2 and the NMR signal is sent to an external MRI apparatus via the coaxial cable 3 for arithmetic processing, thereby obtaining a tomographic image. As a result, optical observation by endoscope and MR
I to diagnose a tomographic image.

Here, generation of a tomographic image by MRI is disclosed in Japanese Patent Application Laid-Open No. 3-228742 and Japanese Patent Application Laid-Open No. 64-49548.
It can be carried out by the same means as that disclosed in the publication. That is, the subject is placed in a static magnetic field generated by the MRI apparatus, a high-frequency signal of a predetermined frequency is transmitted from the MRI apparatus to the loop antenna 2 of the tubular member 1 inserted into the body cavity of the subject, and the subject is Output a high frequency magnetic field. The direction of the high-frequency magnetic field is desirably orthogonal to the direction of the static magnetic field. Then, the NMR signal from the subject is received by the loop antenna 2 and sent to the MRI apparatus via the coaxial cable 3. In the MRI apparatus, information (NMR parameters) such as relaxation time is detected by arithmetically processing the NMR signal, and a tomographic image is generated. Since the relaxation time of the obtained NMR signal is different between the normal tissue and the abnormal tissue such as cancer, it is possible to detect an abnormal site deep under the mucosa based on the tomographic image.

Next, the directivity of the MRI antenna will be described with reference to FIGS. In the present embodiment, a loop antenna 2 as shown in FIG. 1 is used as an antenna. FIG. In such a loop antenna 2, when a radio wave radiated from a certain point crosses the inside of the loop, a current is induced in the loop to function as an antenna. It is well known that radio waves coming from a direction that does not cross the loop are not detected.

The directional characteristics of the loop antenna 2 are indicated by arrows in FIGS. FIG. 5 is a diagram viewed from obliquely above in the direction C in FIG. 4, and FIG. 6 is a diagram viewed from the front in the direction D in FIG. As described above, the loop antenna 2 has a strong sensitivity in a direction close to the loop perpendicular to the loop (solid arrow), and has no sensitivity in a direction close to the loop parallel to the loop (arrow indicated by the broken line). It is a characteristic.

Since the loop antenna 2 is electrically and mechanically protected by being sandwiched between the outer tube 1a and the inner tube 1b of the tubular member 1, the loop antenna 2 does not deteriorate due to body fluids and the like, and is durable. Can be improved.

On the other hand, in the endoscope 4 inserted through the tubular member 1, an optical image of the living tissue is observed through the opening 5 through the objective lens 7, and at the same time, the treatment is made to protrude from the channel opening 8 through the opening 5. It is possible to perform access to living tissue by the tool 9, for example, biopsy with biopsy forceps, ablation treatment with a high-frequency snare, and the like.

That is, the surgeon directly accesses the diseased part and performs a treatment based on two different real-time image information of the MR tomographic image by the loop antenna 2 and the optical image of the endoscope by the endoscope 4. Can be.

In the configuration of this embodiment, the loop antenna 2
Since the (tubular member 1) and the endoscope 4 are provided separately and only the endoscope 4 is inserted through the tubular member 1, the operator can freely adjust the relative positions of the two as needed. Position adjustment can be performed. At this time, the optical observation by the endoscope 4 and the treatment by the treatment tool 9 can be performed through the opening 5 provided in a direction substantially coincident with the directional characteristic of the loop antenna 2. Optical image by endoscope and M
It is easy to associate with a tomographic image by RI, and it is possible to quickly and accurately determine a site to be treated.

As described above, according to the present embodiment,
Based on the optical image by the endoscope and the tomographic image by MRI,
It is possible to perform safer and more reliable diagnosis and treatment.

FIG. 7 shows an MR according to a second embodiment of the present invention.
It is a perspective view which shows the structure at the time of use combining the tube for I observation and an endoscope.

The MRI observation tube according to the second embodiment has a loop antenna 2 and an opening 5 provided at the distal end of a tubular member 11 as in the first embodiment. The endoscope 4 can be inserted into the cavity. The coaxial cable 3 electrically connected to the loop antenna 2 extends from the proximal end of the tubular member 11, is connected to a preamplifier 12, and is connected to an MRI apparatus (not shown) via the preamplifier 12.

At the tip of the tubular member 11, the tubular member 11
A fixing member 13 for fixing to the endoscope 4 is wound and attached. As the fixing member 13, a contracting fixing band or tube, an adhesive fixing tape, a fastening thread for binding and fixing, or the like is used.

The basic operation is the same as that of the first embodiment. When the endoscope 4 confirms the position of the loop antenna 2 and obtains a tomographic image by MRI using the loop antenna 2 to make a diagnosis. At the same time, an optical image of the living tissue can be observed by the objective optical system of the endoscope 4 through the opening 5, and further, the treatment tool is protruded from the channel opening through the opening 5 to perform treatment on the living tissue. It is possible to do.

In the second embodiment, when a tomographic image is diagnosed by MRI, known impedance matching, signal amplification, and the like are performed by the preamplifier 12, so that the SN ratio of the received signal can be improved. it can.

Since the tubular member 11 is fixed to the insertion portion of the endoscope 4, the operability at the time of insertion into the body cavity is good, and the observation optical system of the endoscope 4 is improved. Since the positional relationship between the endoscope and the loop antenna 2 is fixed, the correspondence between the optical image by the endoscope and the tomographic image by MRI is clarified.

As described above, according to the second embodiment, the first
In addition to the effects of the embodiment, the surgeon can easily perform operations such as insertion when guiding the MRI observation tube and the endoscope into the body cavity. In addition, since the relative positional relationship between the endoscope optical image and the MR tomographic image is determined, it is possible to more easily compare the two images at the time of image diagnosis.

FIGS. 8 to 10 relate to a third embodiment of the present invention. FIG. 8 is a perspective view showing a configuration when an MRI observation tube and an endoscope are used in combination, and FIG. A
FIG. 10 is a sectional view taken along the line BB of FIG. 8.

The MRI observation tube of the third embodiment has a base formed by a tubular member 21 having at least a distal end formed of a transparent material such as glass, and is provided with a loop antenna 2 and a coaxial cable 3. . Tubular member 2
1 includes an outer tube 21a and an inner tube 21b as in the first embodiment, and a loop antenna 2 is disposed between these tubes. That is, the configuration is the same as that of the first embodiment except that the tubular member 21 is made of a transparent material to provide an optical opening inside the loop antenna 2 instead of providing a mechanical opening. Have been. The transparent material at the distal end of the tubular member 21 may be a hard material.

As described above, since the inside of the loop antenna 2 in the tubular member 21 is transparent, observation with the endoscope 4 can be performed through this optical opening, and laser light or radiation as therapeutic electromagnetic energy can be obtained. It is possible to irradiate the observation site by transmitting light.

In the third embodiment, the insertion portion of the endoscope 4 is inserted into the lumen of the tubular member 21 to introduce the tubular member 21 and the endoscope 4 to a target site in the body cavity. Member 2 while diagnosing an optical image by MRI and a tomographic image by MRI
In 1, the treatment tool 22 is slightly protruded from the channel opening 8 of the endoscope 4 to access the living tissue in a non-contact manner,
Optical therapeutic procedures can be performed.

As the treatment tool 22, for example, an optical means such as a laser probe and a small-ray source (iridium) catheter is used. When a laser probe is used, a living body tissue is irradiated with a laser beam, and when a brachytherapy catheter is used, a gamma ray is irradiated on the living tissue to perform cautery treatment or the like.

At the time of diagnosis and treatment, the tubular member 2
Since the distal end of 1 is transparent, it is easy to search for an endoscope optical image near the loop antenna. Other operations are the same as those of the first embodiment.

As described above, according to the third embodiment, it is possible to perform an optical treatment at the same time as the diagnosis based on the endoscope optical image and the MR tomographic image, and it is safer and more reliable as in the first embodiment. Diagnosis and treatment can be performed.

FIGS. 11 and 12 relate to a fourth embodiment of the present invention. FIG. 11 is a perspective view showing a configuration when an MRI observation tube and an endoscope are used in combination, and FIG. It is sectional drawing which shows the state at the time of treatment.

In the fourth embodiment, the first to third embodiments
A configuration example of an MRI observation tube in which an opening 32 is provided in front of a tubular member 31 is different from that in which an opening is provided on a side of a tubular member as in the embodiment.

The tubular member 31 is formed of a short cylindrical member made of a transparent material such as glass or resin, and has an opening 3 at its tip.
2 and is attached to the distal end of the direct-view type endoscope 33 in a hood shape. The tubular member 31 is provided with a loop antenna 34 having a circular shape in the circumferential direction. The coaxial cable 3 is electrically connected to the loop antenna 34 and extends rearward, and is connected to an MRI apparatus (not shown). ing.

Although not shown in detail, the tubular member 3
A fixing means such as a fitting part is provided between the endoscope 1 and the distal end of the endoscope 33 so that the tubular member 31 does not easily fall off. The coaxial cable 3 is disposed along the outside of the insertion section of the endoscope 33, and is fixed to the insertion section by a thread, a tape, or the like.

In the fourth embodiment, the tubular member 31 is attached to the distal end of the endoscope 33, and the tubular member 31 and the endoscope 3 are attached.
3 is introduced into a target site in the body cavity, and the tissue in front of the opening 32 of the tubular member 31 is subjected to M by the loop antenna 34.
At the same time that the tomographic image is diagnosed by the RI, the optical image can be observed by the endoscope 33. At the same time, the tubular member 3 passes through the channel opening of the endoscope 33.
The treatment tool 35 can be protruded from the one opening 32 to access the living tissue and perform an endoscopic treatment.

FIG. 12 shows a treatment tool 35 as an example of a therapeutic treatment.
1 shows a state in which a living tissue 36 such as an organ is cauterized using a microwave radiating needle. As shown in FIG. 12, the optical image of the mucous membrane on the surface of the living tissue 36 obtained by the endoscope 33 and the tomographic image to the deep part of the living tissue 36 obtained by the loop antenna 34 can be diagnosed at the same time. The degree range can be observed relatively easily.

As described above, according to the fourth embodiment, the first
Similar to the embodiment, the medical treatment can be performed at the same time as the diagnosis using the endoscope optical image and the MR tomographic image, and the direct-view diagnosis and the medical treatment can be performed more safely and reliably. In addition, since the tubular member 31 can be easily combined with a general endoscope, an MRI observation tube can be configured at low cost.

The endoscope used in combination with the MRI observation tube of each of the above embodiments may be a flexible endoscope or a hard endoscope, and may be any type of non-magnetic endoscope. Can also be used.

[Supplementary Notes] (1) A tubular member covering at least a part of the insertion portion of the endoscope, an MRI antenna built in the tubular member, and a directional characteristic of the antenna provided on the tubular member An opening that is capable of transmitting electromagnetic energy in a direction substantially coincident with the MRI observation tube.

(2) A tubular member that covers the insertion portion of the endoscope and has a lumen through which the insertion portion can be inserted, an MRI antenna built in a side wall portion of the tubular member, and the tubular member An opening provided in the member and capable of transmitting electromagnetic energy in a direction substantially coinciding with the directional characteristics of the antenna.

(3) The MRI observation according to appendix 1, wherein the tubular member has a lumen through which the insertion portion of the endoscope can be inserted, and is an elongated tubular member that covers the insertion portion up to near the hand side. For tubes.

(4) The tubular member according to Appendix 1, wherein the tubular member is a short cylindrical member having a fixing portion attachable to a distal end portion of the insertion portion of the endoscope, and covering the distal end portion of the insertion portion in a hood shape. Tube for MRI observation.

(5) The MRI observation tube according to appendix 1, wherein the antenna comprises a loop antenna, and the opening is provided inside the loop antenna.

(6) The opening is an opening formed by forming a mechanical hole in a portion of the tubular member in a direction substantially coincident with the directional characteristics of the antenna, and the treatment introduced through the endoscope. MR according to Appendix 1, which can pass through the tool
I observation tube.

(7) The opening is an opening in which at least a portion of the tubular member in a direction substantially coincident with the directional characteristics of the antenna is formed of a transparent member, and the treatment instrument introduced through the endoscope. 2. The MRI observation tube according to claim 1, wherein the MRI observation tube is capable of transmitting electromagnetic energy for treatment from a medical device.

(8) an endoscope for obtaining an optical image of the subject;
It consists of a tubular member that covers at least a part of the insertion portion of the endoscope, and incorporates an MRI antenna in this tubular member,
An MR endoscope apparatus comprising: an MRI observation tube having an opening capable of transmitting electromagnetic energy in a direction substantially matching the directional characteristics of the antenna.

(9) The endoscope is a side-view type endoscope, and the MRI observation tube is formed of an elongated tubular member having a lumen through which an insertion portion of the endoscope can be inserted. 9. The MR endoscope apparatus according to supplementary note 8, wherein the MR endoscope device has the opening toward the front.

(10) The endoscope is a direct-view type endoscope, and the MRI observation tube is formed of a short cylindrical tubular member having a fixing portion that can be attached to a distal end portion of an insertion portion of the endoscope. 9. The MR endoscope device according to claim 8, wherein the MR endoscope device has the opening toward the front.

[0054]

As described above, according to the present invention, it is possible to perform an easy, reliable and safe treatment while performing optical observation with an endoscope and diagnosis of a tomographic image with MRI. There is an effect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration when a tube for MRI observation and an endoscope according to a first embodiment of the present invention are used in combination.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is an operation explanatory diagram for explaining the directivity of an MRI antenna;

FIG. 5 is an arrow view of FIG.

FIG. 6 is an arrow view of FIG. 4 as viewed from the front in the direction D.

FIG. 7 is a perspective view showing a configuration when an MRI observation tube and an endoscope according to a second embodiment of the present invention are used in combination.

FIG. 8 is a perspective view showing a configuration when an MRI observation tube and an endoscope according to a third embodiment of the present invention are used in combination.

9 is a sectional view taken along line AA of FIG. 8;

FIG. 10 is a sectional view taken along line BB of FIG. 8;

FIG. 11 is a perspective view showing a configuration when an MRI observation tube and an endoscope according to a fourth embodiment of the present invention are used in combination.

FIG. 12 is a cross-sectional view illustrating a state during treatment with a treatment tool according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tubular member 2 ... Loop antenna 3 ... Coaxial cable 4 ... Endoscope 5 ... Opening 7 ... Objective lens 8 ... Channel opening 9 ... Treatment tool

Claims (1)

[Claims] A tubular member covering at least a part of an insertion portion of an endoscope; an MRI antenna built in the tubular member; and a directional characteristic of the antenna provided on the tubular member and substantially matching the directional characteristic of the antenna. An opening capable of transmitting electromagnetic energy in a direction, and a tube for MRI observation.