JP3693763B2 - MRI equipment for treatment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a therapeutic MRI apparatus using magnetic resonance.
[0002]
[Prior art]
In general, as a therapeutic MRI apparatus, for example, in Japanese Patent Laid-Open No. 7-213507, a doctor who is provided with two rings in an open main magnet of an MR imaging system and is outside the main magnet in an imaging volume of a gap between the two ring magnets Has been disclosed.
[0003]
[Problems to be solved by the invention]
By the way, when performing a neurosurgery microsurgery (surgery under a microscope) using the system having the above-described conventional configuration, a microscope must be disposed in a gap between two ring magnets. However, since the size of the gap between the two ring-type magnets is limited to a predetermined interval, the front-rear direction is different from the microscope operation that moves the direction of the microscope arranged between the two ring-type magnets in the front-rear and left-right directions. A sufficient space can be taken (in the direction orthogonal to the center axis of the ring), but there is a restriction in the left-right direction (in the direction of the center axis of the ring) that there is not enough space.
[0004]
Therefore, in the above-described conventional configuration, for example, a neurosurgery microsurgery is possible, but since the operation of the microscope is limited, it is difficult to secure a surgical field and a blind treatment must be performed. In some cases, there is also a risk that the operation may be interrupted.
[0005]
The present invention has been made paying attention to the above circumstances, and an object thereof is to provide a safe and compact therapeutic MRI apparatus that can secure a wide working space for an operator, increase the degree of freedom of operation of optical means, and is safe. It is in.
[0006]
[Means for Solving the Problems]
The present invention includes two magnets for generating a static magnetic field, high-frequency signal supply means for supplying a high-frequency signal having a predetermined frequency to a living body placed in a static magnetic field generated by these magnets, In a therapeutic MRI apparatus comprising a detecting means for receiving a magnetic resonance signal in the body generated at the time of supply and obtaining a magnetic resonance image in the body, a gradient magnetic field generating means for forming a gradient magnetic field, and one of the two magnets An optical means for obtaining a living body attached to one first magnet and a real image inside the living body, and a first that is movable with respect to the living body and fixedly held at an arbitrary position. Based on a magnet fixing and holding means, a first magnet position detecting means for detecting the position of the first magnet, and a signal from the first magnet position detecting means. Analyzing means for analyzing the position of moving the other second magnet of the two magnets, and moving the second magnet to a position analyzed by the analyzing means based on a signal from the analyzing means And a second magnet moving / holding means fixed and held at the moving position.
In addition, since one of the two magnets forming a static magnetic field for magnetic resonance imaging is combined with an optical means for obtaining a living body and a real image inside the living body, there is no limit to the approach of the optical means to the living body, Since the magnetic resonance imaging region always exists on the optical center line of the optical means, the optical field and the surgical field of the magnetic resonance imaging always coincide, so that the operability is improved and the safety of the operation is also improved. Further, the integration of the magnet and the optical means and the coincidence of the optical means and the surgical field of the magnetic resonance imaging make the entire apparatus compact by minimizing the range of magnetic resonance imaging.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the appearance of the entire treatment MRI apparatus of this embodiment. As shown in FIG. 1, the MRI apparatus of the present embodiment is provided with a counter electrode type static magnetic field generating magnet 3 made up of a pair of magnets 1 and 2 that are spaced apart from each other. The static magnetic field generating magnet 3 is composed of, for example, a normal conducting magnet (which may be a superconducting magnet or a permanent magnet). As shown in FIG. 3, an RF transmission coil (high frequency signal) that applies a high frequency magnetic field of a predetermined frequency to a patient P (see FIG. 4) placed in a static magnetic field as shown in FIG. (Supply means) 4, MR signal detection coil (hereinafter referred to as RF receiving coil) 5 which is a detection means for detecting MR signals of a predetermined frequency emitted by excited nuclei having spin in the patient, and spatial information in the MR signals. And a gradient magnetic field generating coil (gradient magnetic field generating means) 6 for generating a minute gradient magnetic field for applying a magnetic field.
[0008]
Further, as shown in FIG. 4, the magnets 1 and 2 are formed as preferably small in size so that a local static magnetic field can be generated only for a predetermined part of the patient P lying on the operating table 7. ing. Here, the first magnet 1 of one of the two magnets 1 and 2 can be moved with respect to the living body (patient P) by the first magnet fixing and holding means 8, and the operator S can freely move to a desired position. And can be fixed at a desired position by a fixing mechanism described later. Further, the other second magnet 2 of the two magnets 1 and 2 can be changed in position and direction by a second magnet movement holding means 9 described later.
[0009]
The first magnet fixing and holding means 8 has a first arm 12 having one end rotatably connected to the upper end of the main body 10 of the MRI apparatus via a first joint portion 11, and the first arm 12. A second arm 14 whose lower end is rotatably connected to the other end of the first arm via a second joint 13, and one end of the second arm 14 is rotatable via a third joint 15. The connected third arm 16, the fourth arm 18 having one end rotatably connected to the other end of the third arm 16 via the fourth joint portion 17, and the other of the fourth arm 18 A fifth arm 20 having one end rotatably connected to the end via a fifth joint 19 and a magnet holder 21 fixed to the other end of the fifth arm 20 are provided. The first magnet 1 is fixed to the magnet holder 21.
[0010]
Further, joint fixing means (not shown) and rotation are provided in the joint portions 11, 13, 15, 17, and 19 of the respective arms 12, 14, 16, 18, and 20 of the first magnet fixing and holding means 8. An angle detection means (not shown) is embedded. In addition, handles 22 a and 22 b are attached to the magnet holder 21. The first magnet 1 can be freely moved by the operator S holding the handles 22a and 22b, and can be fixed at a position desired by the operator. It is like that.
[0011]
Further, the second magnet movement holding means 9 is provided with a position control arm portion 23. The position control arm 23 includes a first arm 24 having a base end rotatably connected to a lower end of the main body 10 of the MRI apparatus, and a base end connected to the distal end of the first arm 24 as a first joint. A second arm 26 rotatably connected via a portion 25, an L-shaped support member 27 having a lower end fixed to the tip of the second arm 26, and the L-shaped support member 27. And a magnet holder 29 whose base end portion is rotatably connected via a second joint portion 28. The second magnet 2 is fixed to the upper end portion of the magnet holder 29.
[0012]
A surgical microscope (optical means) 30 for obtaining a living body and a real image inside the living body is integrally attached to the first magnet 1. Here, an eyepiece 31 of the surgical microscope 30 is disposed on the upper surface side of the magnet 1, and an objective lens (not shown) of the surgical microscope 30 is disposed on the lower surface side of the magnet 1. Here, the optical axis of the surgical microscope 30 is set to coincide with the magnetic flux of the static magnetic field formed by the static magnetic field generating magnet 3, and the optical axis of the surgical microscope 30 is always set to coincide with the central axis of MRI imaging. ing. Then, the operator S can view an actual image in the static magnetic field generated by the static magnetic field generating magnet 3 through the eyepiece lens 31.
[0013]
FIG. 3 shows a control circuit 32 for performing MR signal processing and overall control of the MRI apparatus of the present embodiment. The control circuit 32 is connected to the RF transmitter coil 4 provided in the static magnetic field generating magnet 3 and forms an RF magnetic field having a predetermined frequency, and is provided in the static magnetic field generating magnet 3. The RF receiver 34 is connected to the RF receiver coil 5 and receives the MR signal detected by the RF receiver coil 5, and is connected to the RF receiver 34 and the RF transmitter 33. A tuning circuit 35 for adjusting the transmission / reception band, a gradient magnetic field amplifier 36 connected to the gradient magnetic field generating coil 6 provided in the static magnetic field generating magnet 3, and the gradient magnetic field amplifier 36 are controlled to adjust the gradient magnetic field strength. Control circuit 37, first magnet movement amount detection circuit (first magnet position detection means) 38 for detecting the movement amount of first magnet 1, and position determination of second magnet 2 A second magnet movement control circuit 39 for controlling a CPU (analyzing means) 40 for governing the control circuit 32, a console 41 serving as an operation means is provided with a sequencer 42.
[0014]
In addition, a console 41, a sequencer 42, a control circuit 37, a first magnet movement amount detection circuit 38, a second magnet movement control circuit 39, and a tuning circuit 35 are connected to the CPU 40, respectively. Further, an RF transmitter 33 and a gradient magnetic field amplifier 36 are connected to the sequencer 42.
[0015]
The amount of movement of the first magnet 1 moved by the operator S is based on the rotation angle detection means embedded in each joint portion 11, 13, 15, 17 and 19 of the first magnet fixing and holding means 8. The rotation angle data obtained by (not shown) is processed by the CPU 40 embedded in the MRI apparatus main body 10 and is grasped three-dimensionally by the CPU 40.
[0016]
Further, the second magnet 2 is positioned to an optimum position for obtaining MR imaging by the position control arm unit 23. Here, the optimum position for obtaining MR imaging is calculated by the CPU 40 with respect to the ideal position of the second magnet 2 with respect to the three-dimensional position of the first magnet 1 processed by the CPU 40. The position control arm unit 23 positions the second magnet 2 based on the result.
[0017]
Next, the operation of the MRI apparatus having the above configuration will be described. When microsurgery is performed simultaneously while obtaining a tomographic image of the affected area of the patient P using the MRI apparatus of the present embodiment, the following operation is performed. First, with the patient P lying on the operating table 7, the operator S holds the handles 22 a and 22 b of the MRI apparatus and moves the magnet 1 to the operating field while looking through the eyepiece 31 of the operating microscope 30. At this time, the movement amount of the first magnet 1 moved by the operator S is detected by the first magnet movement amount detection circuit 38, and the detection data from the first magnet movement amount detection circuit 38 is input to the CPU 40. Is done.
[0018]
Further, the detection data of the movement amount of the first magnet 1 is a rotation angle detecting means (not shown) embedded in each joint portion 11, 13, 15, 17, and 19 of the first magnet fixing and holding means 8. 3) is processed by the CPU 40 based on the rotation angle data obtained by (3), and is grasped three-dimensionally by the CPU 40.
[0019]
Then, based on the control signal from the CPU 40, the second magnet 2 is positioned at the optimum MRI imaging position by the position control arm unit 23 following the movement of the first magnet 1. Here, the optimum position for obtaining MR imaging is calculated by the CPU 40 with respect to the ideal position of the second magnet 2 with respect to the three-dimensional position of the first magnet 1 processed by the CPU 40. Based on the result, the second magnet 2 is positioned by the position control arm 23.
[0020]
In addition, with the magnet 1 moved to the surgical field, the operator S operates, for example, the high-frequency tweezers 23 to perform normal microsurgery. At this time, the operator S takes a tomographic image of the microscopic surgical field as necessary. In this case, since the movement of the magnet 1 is already followed and the magnet 2 is positioned at the optimum position for MRI imaging, a tomographic image can be taken immediately.
[0021]
Therefore, in the above configuration, the operation microscope 30 for obtaining a living body and a real image inside the living body is integrally formed with one of the two magnets 1 and 2 that form a static magnetic field for magnetic resonance imaging. Since it provided, the conventional restriction | limiting in the approach to the biological body of the surgical microscope 30 is lose | eliminated, and the freedom degree of operation of the surgical microscope 30 can be raised compared with the past.
[0022]
The optical axis of the surgical microscope 30 is set to coincide with the magnetic flux of the static magnetic field formed by the static magnetic field generating magnet 3, and the optical axis of the surgical microscope 30 is always set to coincide with the central axis of MRI imaging. Therefore, there is always a magnetic resonance imaging region on the optical center line of the surgical microscope 30. For this reason, the surgical microscope 30 and the magnetic resonance imaging field of operation always coincide, and tomographic imaging can be performed quickly, so that the operability of the MRI apparatus is improved and the safety of the operation is improved. Can be planned.
[0023]
Furthermore, the integration of the first magnet 1 and the surgical microscope 30 and the coincidence of the surgical microscope 30 and the surgical field of the magnetic resonance imaging make the entire apparatus compact by minimizing the range of magnetic resonance imaging. Become. Moreover, since the two magnets 1 and 2 can be easily moved independently, a static magnetic field can be locally formed and all operations can be performed safely.
[0024]
In the present embodiment, the RF transmitter 33 and the RF receiver 34 are embedded in the static magnetic field generating magnet 3, but the surface coil is installed outside the static magnetic field generating magnet 3, that is, on the surface of the patient P. It is also possible to give the function to the etc.
[0025]
It is also possible to detect the amount of movement of the first magnet 1 with an optical position detection system (manufactured by Pixsys Corporation) disclosed in Japanese Patent Laid-Open No. 7-213507, for example, and process it by the CPU 40. is there.
[0026]
Furthermore, the second magnet 2 may not always follow the movement of the first magnet 1, but the second magnet 2 may be positioned only at the time of tomographic imaging. There is an effect that the complicated movement of the second magnet 2 is eliminated.
[0027]
FIG. 5 shows a second embodiment of the present invention. In this embodiment, an endoscope holder 51 is provided as an optical means attached to the first magnet 1 in place of the surgical microscope 30 in the first embodiment (see FIGS. 1 to 4). Is different from the first embodiment.
[0028]
An endoscope 52 is detachably attached to the endoscope holder 51. A television camera 53 is attached to the operation unit of the endoscope 52. Further, the television camera 53 is connected to a monitor 56 via a camera cable 54 and a CCU 55.
[0029]
Further, one end of a light guide cable 57 is connected to the operation part of the endoscope 52. The other end of the light guide cable 57 is detachably connected to the light source device 58.
[0030]
Next, the operation of the MRI apparatus having the above configuration will be described. When performing an endoscopic operation at the same time while obtaining a tomographic image of the affected area of the patient P using the MRI apparatus of the present embodiment, the following operation is performed. First, the operator S holds the handles 22a and 22b of the MRI apparatus while the patient P is laid on the operating table 7 and observes the endoscopic image on the monitor 56 while moving the distal end of the endoscope 52 to a desired position. And induce. At this time, similarly to the first embodiment, the second magnet 2 is moved by the position control arm unit 23 following the movement of the first magnet 1 moved by the operator S, and reaches the optimum position for MRI imaging. Positioned. Note that tomographic imaging using the MRI apparatus is the same as that in the first embodiment.
[0031]
In the present embodiment, the endoscopic image displayed on the monitor 56 is an upright image, but the endoscopic image is reversed left and right, and a signal just reflected by the mirror is displayed on a second monitor (not shown). Is also possible. This is effective when two surgeons are performed as in normal operation when performing endoscopic surgery.
[0032]
That is, during the endoscopic operation, the two operators are positioned on the left and right of the patient sleeping on the operating table 7. For this reason, when two surgeons observe an endoscopic image with one monitor, one surgeon sees a reverse image. Therefore, in this case, two monitors are used, one is an upright image, and the other is a mirror image that is reversed left and right, so that the right and left surgeons of the patient can observe the correct endoscopic image. be able to.
[0033]
FIG. 6 shows a third embodiment of the present invention. In the present embodiment, the light source device 58 and the CCU 55 of the MRI apparatus shown in the second embodiment (see FIG. 5) are integrated and embedded in the main body 10 of the MRI apparatus. Further, two liquid crystal monitors 61 a and 61 b are rotatably attached to the fifth arm 20 of the first magnet fixing and holding means 8 by the monitor support arm 31.
[0034]
The light guide cable 57 and the camera cable 54 are connected to a connection connector 63 provided on the fifth arm 20 of the first magnet fixing and holding means 8. Further, the monitor 56 is connected to an external connection terminal 64 provided on the main body 10.
[0035]
The operation of this embodiment is substantially the same as that of the second embodiment. However, two liquid crystal monitors 61a and 61b are arranged in the vicinity of the operator S, and an endoscopic image is displayed on one liquid crystal monitor 61a and an MR tomographic image is displayed on the other liquid crystal monitor 61b. The environment can be realized.
[0036]
Further, in the MR tomographic image of the liquid crystal monitor 61b, for example, temperature change monitoring can be performed as a monitoring function of focused ultrasound treatment, and temperature change monitoring may be confirmed by color change, for example. Further, the temperature change may be recognized as a relative temperature change between the target part and the peripheral part and displayed on the liquid crystal monitor 61b.
[0037]
Further, it may include an image processing function for recognizing a boundary line between a treatment target part and a non-treatment target part and emphasizing it. Further, the boundary line may be emphasized with a certain width, which may be a surgical margin for an area to be treated.
[0038]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.
Next, other characteristic technical matters of the present application are appended as follows.
(Additional Item 1) Two first and second magnets for generating a static magnetic field are provided, and a high-frequency signal having a predetermined frequency is given to a living body placed in the static magnetic field generated by these magnets. In a therapeutic MRI apparatus for obtaining a magnetic resonance image in the body by receiving a magnetic resonance signal generated in the body at that time, a gradient magnetic field generating means for forming a gradient magnetic field, a living body attached to the first magnet, and Optical means for obtaining a real image inside the living body, fixed holding means that can move the first magnet relative to the living body and that is fixed and held at an arbitrary position, and detects the position of the first magnet From the first magnet position detecting means, the analyzing means for analyzing the position to which the second magnet is moved based on the signal from the first magnet position detecting means, and the analyzing means And a driving / holding means for driving and fixing the second magnet based on the signal.
[0039]
(Additional Item 2) The therapeutic MRI apparatus according to Additional Item 1, wherein the magnetic flux of the static magnetic field formed by the two magnets coincides with the optical axis of the optical means.
[0040]
(Additional Item 3) Two magnets for generating a static magnetic field are provided, a high-frequency signal having a predetermined frequency is given to a living body placed in the static magnetic field generated by these magnets, and the magnetism generated in the body is generated at that time. An MRI apparatus that receives a resonance signal and obtains a magnetic resonance image inside the body, including a gradient magnetic field generating means for forming a gradient magnetic field, and an optical means for obtaining a living body and an actual image inside the living body in one of the magnets The position of the magnet provided with the optical means can be freely changed with respect to the living body, the fixing means for fixing the position at an arbitrary position is provided, and the fixing position of the magnet provided with the optical means Analyzing means for analyzing where the other magnet should be positioned, and moving the other magnet to the position analyzed by the analyzing means. An MRI apparatus for treatment, characterized by comprising a driving means for fixing there.
[0041]
(Additional Item 4) The apparatus or system according to Additional Item 3, wherein the magnet that generates the static magnetic field is a superconducting magnet.
[0042]
(Additional Item 5) The apparatus or system according to Additional Item 3, wherein the magnet that generates the static magnetic field is a normal conducting magnet.
[0043]
(Additional Item 6) The apparatus or system according to Additional Item 3, wherein the magnet that generates the static magnetic field is a permanent magnet.
[0044]
(Additional Item 7) The apparatus or system according to Additional Item 3, wherein the optical means is a surgical microscope.
[0045]
(Additional Item 8) The apparatus or system according to Additional Item 3, wherein the optical means is an endoscope.
[0046]
(Additional Item 9) The apparatus or system according to Additional Item 3, wherein the endoscope is detachably attached.
[0047]
【The invention's effect】
According to the present invention, the optical means for obtaining the living body and the real image inside the living body is attached to the first magnet of one of the two magnets, so that it is possible to secure a wide working space for the operator and freedom of operation of the optical means. It is possible to provide an MRI apparatus for treatment that is safe and compact.
[Brief description of the drawings]
FIG. 1 is a perspective view of an entire treatment MRI apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram illustrating a connection state of control devices of the therapeutic MRI apparatus according to the first embodiment.
FIG. 3 is a schematic configuration diagram showing a control circuit of the therapeutic MRI apparatus according to the first embodiment.
FIG. 4 is a perspective view showing a usage state of the first embodiment.
FIG. 5 is a perspective view of the entire treatment MRI apparatus according to a second embodiment of the present invention.
FIG. 6 is a perspective view of the entire treatment MRI apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st magnet 2 2nd magnet 4 RF transmission coil (high frequency signal supply means)
5 MR signal detection coil (detection means)
6 Gradient magnetic field generating coil (Gradient magnetic field generating means)
8 First magnet fixing and holding means 9 Second magnet moving and holding means 30 Surgical microscope (optical means)
38 1st magnet movement amount detection circuit (1st magnet position detection means)
40 CPU (analysis means)

Claims (1)

Two magnets that generate a static magnetic field, high-frequency signal supply means for supplying a high-frequency signal having a predetermined frequency to a living body placed in a static magnetic field generated by these magnets, and a high-frequency signal that is generated when the high-frequency signal is supplied A therapeutic MRI apparatus comprising a detection means for receiving a magnetic resonance signal in the body and obtaining a magnetic resonance image in the body,
A gradient magnetic field generating means for forming a gradient magnetic field, a living body attached to one of the two magnets, an optical means for obtaining a real image inside the living body, and the first magnet as a living body The first magnet fixing and holding means that is movable with respect to and fixed at an arbitrary position, the first magnet position detecting means that detects the position of the first magnet, and the first magnet position detection Analyzing means for analyzing a position to move the other second magnet of the two magnets based on a signal from the means; and based on a signal from the analyzing means, the position analyzed by the analyzing means A therapeutic MRI apparatus comprising: a second magnet moving and holding means for moving the second magnet and fixing and holding the second magnet at the moving position.

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