JPH09299346A - Diagnosing and treatment device for mri and medical diagnosing and treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the influence of a device upon a magnetic field of a MR photographing area by letting a diagnosing and treatment device have magnetism determined according to a calculation expression which quantitatively shows the holding relationship between the allowable value of uniformity coefficient of a static magnetic field of a photographing area and the accessible distance of a diagnosing and treatment device to the photographing area. SOLUTION: A controller 35 takes image data by each slice section from an operation unit 36, and after processing of judging whether the picture element value of picture elements of a processing object is higher than a threshold value or not is repeated for all picture elements, it is judged whether a marker element exists in the slice section in the course of being processed or not. Further, the controller 35 reads three-dimensional data of an impermissible area where the scope tip hard part 73 is not permitted to exist, and if the current three-dimensional position of the marker element enters the impermissible area according to the reference fixed position set in a gantry of a MRI device 11 and the position of the marker element in the slice section, a warning device 40 is operated to generate a warning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diagnostic treatment instrument for MRI such as a scope of an endoscopic device, a scope of an ultrasonic diagnostic device, and other treatment tools used during MR imaging by an MRI device. The present invention also relates to a medical diagnosis / treatment system using the diagnostic / treatment device.

[0002]

2. Description of the Related Art An MRI apparatus (magnetic resonance imaging apparatus) is widely used in the medical field. The MRI apparatus magnetically excites nuclear spins of a subject placed in a static magnetic field with a high-frequency signal of Larmor frequency, reconstructs an image based on an MR signal generated by this excitation, or This is a device that obtains spectral information related to spin behavior.

In recent years, a diagnostic method using this MRI apparatus for intraoperative imaging has been performed. in this case,
A mode is adopted in which the MRI apparatus and another modality such as an ultrasonic diagnostic apparatus or an endoscope apparatus are combined to form a composite diagnostic system, or the MRI apparatus and a treatment tool such as forceps are used in combination. .

Since the MRI apparatus is extremely reluctant to disturb the homogeneity of the static magnetic field particularly in the imaging region, this MR
It is necessary to consider the magnetic field homogeneity in the modality and the treatment tool combined with the I-device. Specifically, MRI
It is necessary to take measures such as not inserting the modality's probe or treatment tool into at least the photographing area during photographing, or making a portion close to the photographing area with a non-magnetic material. It should be noted that the imaging region referred to here means not only the imaging cross-section taken out as an image of the subject but also the entire region that magnetically affects the imaging cross-section.

[0005]

Considering the influence on the homogeneity of the magnetic field and the characteristics of intraoperative imaging, it is desirable that the instrument used during MR imaging is made of a non-magnetic material.

However, it is practically impossible to give them complete non-magnetism, and it is unclear how much non-magnetism is conventionally required for these devices, and it is simply as non-magnetic as possible. Since it was manufactured under the condition that it had magnetism, there was a problem that the degree of non-magnetism of the equipment became excessive, and conversely it was too small. In the former case, it is a so-called "over-spec" state. Since the material that can be used as the non-magnetic material is largely restricted and is usually more expensive than the magnetic material, the "over-spec" state causes an increase in manufacturing cost. On the other hand, in the latter case where the degree of non-magnetism is low, when the device is placed in the imaging region, the magnetic field is disturbed, which may deteriorate the image quality.

[0007] Further, conventionally, the operator can know the conditions of use of such an instrument (for example, non-magnetic degree, distance at which an imaging region can be approached, etc.) during the operation in a timely manner and with his / her own eyes. Even if the surgeon is concerned about the effect on the magnetic field, it is often difficult to deal with it properly because it has not been done, and the tool is evacuated from the imaging area more than necessary. It wasted unnecessary operations and contributed to the lengthening of examinations and surgery.

The present invention has been made in view of such a conventional situation, and a diagnostic and therapeutic instrument used together with an MRI apparatus is provided with a magnetism which matches the usage state of the instrument in advance, or the instrument. By preliminarily recognizing the degree of magnetism and managing the usage state, it is possible to reliably prevent the influence of the instrument on the magnetic field in the MR imaging region, eliminate unnecessary operations, and perform efficient MR imaging and diagnosis. -The purpose is to enable treatment.

[0009]

In order to achieve the above object, according to one aspect of the diagnostic treatment apparatus for MRI of the present invention,
A diagnostic and therapeutic device for use with an MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of nuclear spins in an imaging region of a subject placed in a static magnetic field, the tolerance of the homogeneity of the static magnetic field in the imaging region, and the diagnosis. It is characterized in that it has a magnetism determined based on a calculation formula that quantitatively expresses a holding relationship with the approachable distance of the therapeutic instrument to the imaging region.

According to another aspect of the diagnostic treatment apparatus for MRI of the present invention, the diagnostic treatment for use with an MRI apparatus for obtaining a signal based on the magnetic resonance phenomenon of nuclear spins of an imaging region of a subject placed in a static magnetic field. A device, which can be accessed based on a calculation formula that quantitatively expresses a holding relationship between the allowable value of the homogeneity of the static magnetic field in the imaging region and the accessible distance of the diagnostic treatment device to the imaging region. It is characterized in that a distance indicating means for clearly indicating the distance is provided.

Further, according to another aspect of the diagnostic and therapeutic device for MRI of the present invention, the MRI for obtaining a signal based on the magnetic resonance phenomenon of the nuclear spin of the imaging region of the subject placed in the static magnetic field.
A diagnostic and therapeutic device for use with an apparatus, which can maintain the homogeneity of the static magnetic field of the imaging region within an allowable value, and quantitatively determines the accessible distance to the imaging region of the diagnostic and therapeutic device for each imaging condition. It is characterized by having a management means for managing the accessible distance.

Preferably, the calculation formula is

[Equation 2] Where B ₀ : strength of the static magnetic field, ΔB:
Amount of change in magnetic field, Δr: required resolution, μ ′: relative permeability of material of the device, V: volume of material of the device, r:
The distance between the position of the material of the device and the imaging area (the accessible distance).

Further, preferably, the diagnostic treatment instrument is any one of a scope of an electronic endoscope apparatus, a probe of an ultrasonic diagnostic apparatus, and a treatment tool.

On the other hand, in order to achieve the above-mentioned object, the medical diagnosis / treatment system of the present invention comprises an MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of a nuclear spin in an imaging region of a subject placed in a static magnetic field. A position detecting means for detecting the position of the diagnostic treatment instrument in a three-dimensional space including the imaging area, and a diagnostic treatment instrument used in association with the subject together with the MRI apparatus; And a judgment means for judging whether or not the diagnostic treatment instrument is in an allowable position state existing at a position where the homogeneity of the static magnetic field of the imaging region can be within the allowable value based on the detection information. Characterize.

Preferably, there is provided warning means for issuing a warning when the judging means judges that the position is not in the allowable position state.

Further, for example, the diagnostic treatment instrument is a scope of an electronic endoscope apparatus, and the position detecting means is provided with an MR marker provided on a distal end hard portion of the scope.

Further, for example, the allowable value of the homogeneity of the static magnetic field in the imaging region is set for each imaging sequence.

[0018]

DETAILED DESCRIPTION OF THE INVENTION One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic configuration of a medical diagnosis / treatment system according to this embodiment. This medical diagnosis / treatment system is a composite type system in which an MRI (magnetic resonance imaging) device 11 and an electronic endoscope device 12 are combined, and the MRI device 11 can perform intraoperative imaging.

First, the MRI apparatus 11 will be described.

This MRI apparatus includes a bed part on which the subject P is placed, a magnet part for generating a static magnetic field, a gradient magnetic field part for adding position information to the static magnetic field, a transmitting / receiving part for transmitting / receiving a high frequency signal, It has a system control and a control / arithmetic unit responsible for image reconstruction.

The magnet portion is, for example, a superconducting magnet 21.
And a static magnetic field power supply 22 for supplying a current to the magnet 21, and generates a static magnetic field H ₀ in the axial direction (Z-axis direction) of the cylindrical opening (diagnostic space) into which the subject P is loosely inserted. Let it.
It should be noted that this magnet part has a shim coil 2 for primary shimming.
3 are provided. A current for homogenizing the magnetic field is supplied to the shim coil 21 from the shim coil power supply 24 under the control of a controller described later. The couch portion is configured such that the top plate 25 on which the subject P is placed can be inserted into the opening of the magnet 21 so as to be retractable.

The gradient magnetic field unit includes a gradient magnetic field coil unit 28 incorporated in the magnet 21. The gradient magnetic field coil unit 28 includes three sets (types) of x, y, and z coils in the X, Y, and Z axis directions. The gradient magnetic field section further includes x,
A gradient magnetic field power supply 29 for supplying current to the y and z coils and a gradient magnetic field sequencer 5a in a sequencer 30 for controlling the power supply 29 are provided. The gradient magnetic field sequencer 30a includes a computer, and receives a command signal of a pulse sequence for MR data acquisition from a controller 35 (including a computer) that manages the entire apparatus. Accordingly, the gradient magnetic field sequencer 30a controls the application and strength of each of the gradient magnetic fields in the X, Y, and Z directions according to the commanded pulse sequence, and the gradient magnetic fields can be superimposed on the static magnetic field H _0. ing.

The transmission / reception unit is a high-frequency coil 31 arranged near the subject P in the imaging space inside the magnet 21, and a transmitter 32T and a receiver 32R connected to this coil 31.
And an RF sequencer 30b (with a computer) in the sequencer 30 for controlling the operations of the transmitter 32T and the receiver 32R. The transmitter 32T and the receiver 32R are controlled by the RF sequencer 30b,
While supplying an RF current pulse having a Larmor frequency for exciting nuclear magnetic resonance (NMR) to the high-frequency coil 31, the high-frequency coil 31 receives an MR signal (high-frequency signal) and performs various kinds of signal processing. A corresponding digital signal is formed.

Further, in addition to the controller 35 described above, the control / arithmetic unit includes an arithmetic unit 36 for inputting digital data of the MR signal formed by the receiver 32R and calculating image data and spectrum data. Unit 37 for storing images, display 3 for displaying images
8, an input device 39, and an alarm device 40. The arithmetic unit 36 performs processing such as arrangement of actually measured data in a two-dimensional Fourier space formed by a built-in memory and Fourier transform for image reconstruction.

The controller 35 controls the operation contents and operation timings of the gradient magnetic field sequencer 30a and the RF sequencer 30b while synchronizing them, while processing the information sent from the electronic endoscope apparatus 12. It is like this. That is, the controller 35
As will be described later, receives information on the orientation of the tip hard part of the soup from the electronic endoscope device 12.

The controller 35 also determines whether or not the position of the rigid portion of the scope tip has entered the permissible area for the MRI imaging area, and if so, issues a warning via the alarm device 40. There is.

The endoscope apparatus 12 comprises a scope 51 and an apparatus main body 52, and the apparatus main body 52 further has a control section 61, an image processing section 62 and an image display section 63 as shown in FIG.
And an image recording unit 64. The scope 51 is connected to the apparatus main body 52 via a cable 53. The cable 53 contains a control line and a signal line.

As shown in FIG. 1, the scope 51 includes an operating portion 71 on the hand side which is held and operated by an operator, and a flexible tube portion which extends from the operating portion 71 and is inserted into the subject. 72, and a distal end hard portion 73 provided at the distal end portion of the flexible tube portion 72 opposite to the proximal side. Further, an insertion opening 71a into which a treatment tool 75 such as a foreign forceps or a high-frequency treatment tool can be inserted is provided at a predetermined position on the operation section 71. This insertion port 71a is connected to the forceps port (see FIG. 3) 81 of the distal end rigid portion 73 through the inside of the flexible tube 72, and causes the treatment instrument 75 to project from the forceps port 81 into the body.
The necessary measures can be taken.

As shown in FIG. 3, the tip rigid portion 73 has an objective lens 82 provided at the tip thereof, and a prism 83 for bending the optical image passing through the objective lens 82.
A CCD 84 that captures an optical image bent by the prism 83 and converts it into an electric signal is provided. This tip hard part 7
3 is further provided with means for detecting the direction in which the tip rigid portion 73 is facing and its three-dimensional position.
As a direction detecting means, a gyroscope 85 is provided at a predetermined axial direction position on the near side of the prism 83. The gyroscope 85 detects the angular velocity associated with the movement of the tip rigid portion 73 in each of the x, y, and z axes, and outputs an electric signal corresponding to this. This angular velocity signal is sent to the MRI apparatus 1
1 to be used to know the orientation of the endoscope. Further, a marker body 86 is provided on the outer peripheral portion of the gyroscope 85 as a part of the elements forming the position detecting means. The marker body 86 includes a medium that can be magnetically detected by the MRI apparatus 11. As this medium, an RF coil, MRI phantom, mineral oil, salad oil, glue or the like is used.

The control unit 61 performs gradation conversion on the electric signal converted by the CCD 84 and supplies the MRI apparatus 11 with angular velocity information about the x, y and z axes of the tip rigid portion 73 obtained by the gyroscope 85. . further,
The control unit 61 controls air supply / water supply from the scope 51 in response to an operation of an air supply / water supply switch (not shown) provided on the operation unit 71.

The image processing unit 62 converts the electric signal, which has been gradation-converted by the control unit 61, into an image signal that can be displayed on the monitor of the image display unit 63. The image display unit 63 includes a monitor (not shown), and displays the image signal converted by the image processing unit 62 on the monitor. Image recording unit 64
Includes an image recording device (not shown) such as an image memory and an optical disc, and records the image signal converted by the image processing unit 62 in the image recording device.

The operation unit 71 of the endoscope apparatus 12 according to the present embodiment further has a seal 9 which is one mode of implementation of the present invention.
0 (distance specifying means or management means) is attached. The sticker 90 is attached to the operation portion 71 at the most visible position so that the operator does not overlook it. In the seal 90, the distance at which the flexible tube portion 72 of the scope 51 and the distal end rigid portion 73 thereof can approach the MR imaging region is specified for each image acquisition sequence. With this, the operator can recognize the distance each time the scope 51 is selected and used, so that the approach state of the scope can be manually managed.

Here, the contents of the seal 90 will be further described. In MRI, it is basically said that a magnetic material should not be placed near the imaging area regardless of whether it is inside or outside the gantry. However, it is impossible in reality to completely meet this requirement. In other words, it is difficult to make all instruments completely non-magnetic. Therefore, as one aspect, the distance r (approachable distance: FIG. 4) for approaching the photographing area is known in advance by knowing the degree of magnetism of an instrument that is placed near the photographing area or that may approach the photographing area.
(See) is to be regulated for each shooting condition.

The condition that the magnetic material does not disturb the homogeneity of the static magnetic field in the imaging region of the MRI apparatus is expressed by the following equation.

[0036]

(Equation 3) Where ΔB is the amount of change in the magnetic field, B ₀ is the strength of the static magnetic field, and Δ
r is the required resolution, and the left side "ΔB / B ₀ / Δ
“R” is a quantity representing the degree of disturbance of the magnetic field and is determined by conditions such as the MRI imaging method. An example is shown in FIG. Further, μ ′ is the relative magnetic permeability of the material of the device, V is the volume of the material of the device, r is the distance between the position (approach position) where the material of the device is placed and the imaging region R _img (see FIG. 4), Right side "6
(Μ′−1) V / 4πr ⁴ ”is an amount determined by the weak magnetic substance that is trying to approach the vicinity of the photographing region.

In order to determine the approachable distance r of the diagnostic and therapeutic instrument based on the equation (1), the following procedure is executed in advance.

A. The material of the diagnostic treatment instrument (for example, the scope of the electronic endoscope device) is analyzed to determine the amount of magnetic substance contained in the instrument. B. The approachable distance r is calculated based on the equation (1).

For example, a diagnostic treatment instrument has a size of 1 mm × 1 cm × 1 cm
When (= 0.1 cm ³ ) of aluminum is included, in the formula (1), V = 1 × 10 ⁻⁷ m ³ , μ ′ = 1.00021
It becomes 4. In the case of imaging by the spin echo (SE) method,
Since the left side of the equation (1) = 0.2 ppm / mm, r> 0.00
It will be 27 meters and can be approached up to about 3 mm. In the case of the field echo (FE) method, the left side of equation (1) = 0.04
Since it is ppm / mm, r> 0.0135m, which is about 14
It is possible to approach up to mm. Further, in the EPI method, since the left side of the equation (1) is 0.002 ppm / mm, r> 0.27 m
And can reach up to about 270 mm.

On the seal 90, the approachable distance r thus obtained is specified for each sequence. In this case, instead of specifying the numerical value of the distance r, the degree of magnetism is divided into several classes, and the degree of magnetism itself is a number,
You may display by a symbol and a color.

As a method of obtaining the approachable distance r without depending on the equation (1), there is a method of making an actual measurement. Specifically, specify a predetermined acquisition sequence,
An MR image is obtained by placing a diagnostic treatment instrument near the phantom. The extent to which the MR image artifacts can be approached is determined. The collection sequence is changed as needed, and the accessible distance r for each collection sequence is obtained.

Next, the operation and effect of the diagnosis / treatment system according to this embodiment will be described.

With the subject P mounted on the top plate 25 of the MRI apparatus 11, the scope 51 of the electronic endoscope apparatus 12 is inserted into a desired portion of the subject P. As a result, endoscopic imaging of an optical image through the CCD at the distal end of the scope and necessary endoscopic surgery can be performed as in the conventional case.

If MR photography is required during this process,
An image is taken by the MRI apparatus 11. When the controller 35 commands the sequencer 30 to generate a desired pulse sequence (for example, a multi-slice imaging sequence), the MR image of the desired slice section based on the sequence is displayed on the display unit 3.
8 is displayed. This allows the operator to make a comprehensive treatment decision by combining the MR image (cross-sectional image) and the endoscopic image (display image).

A sticker 90 as a distance indicating means is attached to the operation portion 71 of the scope 51 of the electronic endoscope apparatus 12. On the sticker 90, the approachable distance r to the photographing region is specified for each MR photographing sequence. Therefore, the operator can voluntarily manually adjust the position of the distal end hard portion 73 at the distal end of the scope for MR imaging.

On the other hand, the image data reconstructed by the arithmetic unit 36 of the MRI apparatus 11 can also incorporate the position data of the marker body 86 of the scope distal end rigid portion 73. That is, when the marker body 86 enters the imaging slice section, the marker body 8 is included in the MR image data.
The brightness of the position 6 is higher than that of the surrounding area.

Therefore, the controller 35 takes in the image data for each slice section from the arithmetic unit 36 and performs the processing shown in FIG. First, a pixel to be processed is selected (step S1 in the figure), and it is determined whether the pixel value of the selected pixel is higher than a predetermined threshold value (step S2). After repeating this threshold processing for all pixels (step S3), the controller 35 determines whether or not the marker body 86 is present in the slice section currently being processed (step S4). The controller 35 further reads from the memory the three-dimensional data of the non-permissible area where the scope distal end rigid portion 73 is not allowed (step S5). This non-permissible area data is obtained by adding the approachable distance r determined by the above-described equation (1) to the imaging area data. The imaging region is, for example, determined in advance according to the sequence or the like (or may be determined each time). Next, the controller 35, for example, sets the reference fixed position (not shown) set on the gantry of the MRI apparatus 11 and the marker body 8 in the slice section.
It is determined whether the current three-dimensional position of the marker body 86 is within the non-permissible area based on the position of 6 (step S6). In this process, the controller 35 causes the marker body 8
6, that is, when it is determined that the position of the scope distal end hard portion 73 has entered the non-permissible region, the alarm device 40 is activated to generate an alarm (step S7). As a result, the operator is automatically advised to withdraw the scope away from the current position, and the scope disturbs the homogeneity of the static magnetic field in the imaging region related to MR imaging to an allowable value or more. Can be avoided in advance.

The monitoring process of FIG. 6 is performed by the MR during diagnosis and treatment.
It may be performed in parallel with the photographing, or may be separately performed as a monitor process of the rigid portion of the scope tip by pre-scan before MR photographing.

The alarm may be voice or blinking of a lamp. Further, a warning may be issued via the display 38 using characters, sounds, etc. as a medium.

By the way, the concept of the above embodiment is based on MRI.
Although the degree of magnetism of the diagnostic treatment instrument used with the device is known in advance, the imaging condition (for example, acquisition sequence) and the distance to approach the imaging region are managed.
The opposite concept holds. That is, it is possible to manufacture an instrument to be used with the MRI apparatus based on the above-mentioned condition (1). The outline of the manufacturing process is shown in FIG.

First, as shown in step S11 in the figure, how close the diagnostic and therapeutic instrument is to the imaging area is used is examined to determine the distance r in the equation (1). As the next step S12, a photographing method for photographing while using the apparatus is examined, and the maximum value of “(ΔB / B ₀ ) / Δr” on the left side of the equation (1) is obtained. In the next step S13, the remaining degrees of freedom (μ,
V) is appropriately selected and the material and amount used are determined, and the device is manufactured.

An example of this production will be given below.

As an example, consider MRI imaging with an endoscope scope inserted in the body. For example, when attempting to construct the tip of the endoscope with a part made of stainless steel, (1) since the endoscope can see the affected part from a little distance from the MRI imaging region, r = 0. Decide to 1m. (2) The imaging method is limited to the spin echo method, which is the least affected by the magnetic substance, and the left side is 0.2 ppm / mm. (3) At this time, the equation (1) is

## EQU4 ## (μ'-1) V <4.2 × 10 ^-8 . The material and amount used are selected so as to satisfy this formula. (4) The relative permeability of stainless steel is about 1.003 when the one having the smallest possible permeability is selected. Therefore,

## EQU5 ## The condition of V <1.4 × 10 ^-5 (m ³ ) is obtained. Since the specific gravity of stainless steel is 8 g / cm ³ , it can be used up to 110 g. This is 1mm thick,
It corresponds to a plate of 100 x 140 mm.

Another example is the use of an instrument that uses aluminum when shooting with EPI. (1) Assuming that the image is to be placed very close to the shooting area, r = 2
0 mm. (2) Since EPI is used, the left side of equation (1) is 0.00
It is 2 ppm / mm. (3) At this time, the equation (1) is

## EQU6 ## 6.7 × 10 ^-13 = (μ'-1) V. The material and amount used are selected so as to satisfy this formula. (4) Since the relative magnetic permeability of aluminum is 1.000214,

[Equation 7] V <3.2 × 10 ⁻⁹ . This is 3.2mm x 2mm with a thickness of 0.5mm
Equivalent to the plate material. In this way, by controlling the distance between the imaging region of the rigid tip of the scope as a diagnostic and therapeutic instrument, the state of disturbing the magnetic field of MR imaging can be prevented. This makes it possible to significantly reduce mistakes (redoing) in MR imaging as intraoperative imaging. Further, since the scope can be placed at the minimum required position from the imaging region, it is possible to avoid a situation in which the scope is separated more than necessary and the operation time for endoscopic imaging remarkably increases. Therefore, it is possible to surely perform intraoperative MR imaging to speed up diagnosis and treatment, and
It is possible to provide a composite type diagnosis / treatment system with excellent operation efficiency. Further, by manufacturing a weak magnetic scope or the like that is quantitatively determined under the desired MR imaging conditions, the manufacturing cost is low, and an appropriate usage condition can be realized under the desired MR imaging conditions.

In the above embodiment, the case where the scope of the electronic endoscope apparatus is adopted as the diagnostic and therapeutic instrument used together with the MR imaging has been described, but the diagnostic and therapeutic instrument according to the present invention is used inside or outside the subject or It can be performed both inside and outside the gantry, and can be similarly applied to treatment tools such as scopes, forceps, and scalpels of the ultrasonic endoscope apparatus.

[0056]

As described above, according to the present invention, the MR
The diagnostic treatment device used together with the photographing is determined based on a calculation formula that quantitatively represents the holding relationship between the allowable value of the homogeneity of the static magnetic field in the photographing region and the accessible distance of the diagnostic treatment device to the photographing region (preferably Has magnetism (for each shooting condition),
Position detecting means for detecting a position of the diagnostic treatment instrument in a three-dimensional space including the imaging region, and based on the detection information of the position detecting means, the diagnostic treatment instrument sets the homogeneity of the static magnetic field of the imaging region within the allowable value. And a determining means for determining whether or not the allowable position state exists at a position that can be accommodated in, and further, a warning means for issuing a warning when the determining means determines that the allowable position state is not present. Because I prepared, M
It is possible to surely prevent the influence of the instrument on the magnetic field in the R imaging region, eliminate unnecessary operations, and perform the MR imaging and diagnosis / treatment with high efficiency.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an example of a medical diagnosis / treatment system of the present invention.

FIG. 2 is a functional block diagram of the electronic endoscope apparatus.

FIG. 3 is a schematic cross-sectional view of a rigid tip portion of the scope of the electronic endoscope apparatus.

FIG. 4 is a conceptual diagram illustrating a relationship between an MR imaging region and a device approachable distance.

FIG. 5 is a table showing an example of correspondence between sequence types and allowable values of magnetic field turbulence.

FIG. 6 is an MRI for approach control of a tool in an MR imaging region.
6 is a flowchart showing a processing example of a controller of the device.

FIG. 7 is a conceptual manufacturing flow chart when manufacturing while quantitatively managing the magnetism of the device.

[Explanation of symbols]

 11 MRI device 12 electronic endoscope device 35 controller 36 arithmetic unit 40 alarm device 51 scope (diagnostic treatment instrument) 72 flexible tube portion 73 tip rigid portion 86 marker body 90 seal

Claims (9)

[Claims] 1. A diagnostic and therapeutic device for use with an MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of nuclear spins of an imaging region of a subject placed in a static magnetic field, comprising: A diagnostic treatment instrument for MRI, characterized in that it has magnetism determined based on a calculation formula that quantitatively expresses a holding relationship between an allowable value and an approachable distance of the diagnostic treatment instrument to the imaging region. 2. A diagnostic and therapeutic instrument for use with an MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of nuclear spins in an imaging region of a subject placed in a static magnetic field, the device comprising: It is characterized in that a distance demonstrating means for demonstrating the accessible distance determined based on a calculation formula quantitatively expressing the holding relationship between the allowable value and the accessible distance of the diagnostic treatment instrument to the imaging region is arranged. MR
Diagnostic treatment instrument for I. 3. The calculation formula is as follows: Where B ₀ : strength of the static magnetic field, ΔB:
Amount of change in magnetic field, Δr: required resolution, μ ′: relative permeability of material of the device, V: volume of material of the device, r:
The diagnostic treatment instrument for MRI according to claim 1 or 2, which is a distance between the position of the material of the instrument and the imaging region (the accessible distance). 4. The present invention is applied to any one of a scope of an electronic endoscope apparatus, a probe of an ultrasonic diagnostic apparatus, and a treatment tool as the diagnostic treatment instrument. Diagnostic diagnostic device for MRI. 5. A diagnostic and therapeutic device for use with an MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of nuclear spins in an imaging region of a subject placed in a static magnetic field, the uniformity of the static magnetic field in the imaging region being The accessible distance to the imaging area of the diagnostic and therapeutic instrument that can be held within an allowable value is quantitatively determined for each imaging condition, and a management means for managing this accessible distance is provided. M
Diagnostic treatment equipment for RI. 6. An MRI apparatus for obtaining a signal based on a magnetic resonance phenomenon of nuclear spins of an imaging region of a subject placed in a static magnetic field, and a diagnostic treatment instrument used together with the MRI device in relation to the subject. In a medical diagnosis / treatment system including: a position detection unit that detects a position of the diagnostic treatment device in a three-dimensional space including the imaging region; and the diagnostic treatment device based on detection information of the position detection unit. A medical diagnosis / treatment system, comprising: a determination unit that determines whether or not the homogeneity of the static magnetic field in the imaging region is in a position where the static magnetic field can be contained within the permissible value. 7. The medical diagnosis / treatment system according to claim 6, further comprising warning means for issuing a warning when the judgment means judges that the position is not in the allowable position state. 8. The medical diagnosis / treatment system according to claim 7, wherein the diagnostic treatment instrument is a scope of an electronic endoscope apparatus, and the position detecting means includes an MR marker provided on a distal end rigid portion of the scope. . 9. The medical diagnosis / treatment system according to claim 7, wherein the allowable value of the homogeneity of the static magnetic field in the imaging region is set for each imaging sequence.