JP2003164433A - Medical support system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the usability of MRI images in surgery using a microscope by determining the positional relationship between a field image of the microscope and an MRI image. <P>SOLUTION: This medical support system includes an MRI device 1 with an image display means for displaying tomograms of a subject, a microscope 3 for observing the subject, and a mark display means 11 for displaying a mark over the position of the field image of the microscope 3 to match the position of a portion of interest which is marked on the image displayed by the image display means. The mark display means 11 varies the way the mark is displayed according to a difference in the distance between the mark and the field image along the depth of the subject. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical support system, and more particularly to a technique of a medical support system using a magnetic resonance imaging device under medical treatment using a microscope.

[0002]

2. Description of the Related Art A magnetic resonance imaging apparatus (MRI apparatus) irradiates a living body with a high-frequency magnetic field pulse while applying a uniform static magnetic field to excite atomic nuclei such as hydrogen and phosphorus in the living body.
A device that contributes to medical diagnosis by measuring the magnetic resonance signal generated by this excitation and imaging the measurement region in the living body based on the magnetic resonance information such as the density distribution or relaxation time distribution of hydrogen and phosphorus. is there.

In recent years, I-MRI (Interventional MRI or Intraop) for performing examination and treatment under fluoroscopy by an MRI apparatus.
abbreviated erative MRI) is superior in soft tissue extraction ability compared to the case of using other imaging modalities (medical image diagnostic equipment), is not invasive without X-ray exposure, and is optional. It has begun to spread because of the advantages of being able to photograph cross-sections. For example, in percutaneous treatment such as laser treatment or ultrasonic wave, or surgical operation such as tumor resection, which is performed by surgically performing craniotomy or laparotomy, guide by real-time imaging to reach the affected area with a puncture needle or thin tube. An MRI device is used for visualization of tissue changes during treatment and monitoring of local temperature during heating / cooling treatment. Especially during surgery
By performing RI imaging, the deformation of the organ caused by craniotomy or laparotomy can be grasped. For example, brain shape change (brain shift) caused by changes in brain pressure due to craniotomy,
By performing intraoperative MRI imaging of the tissue condition at the time of tumor resection, which has not been observable until now, accurate information can be obtained, leading to an improvement in the tumor resection rate. Further, even during surgery performed while observing the surgical site with a microscope, the operator can advance the surgical instrument to the position of the tumor or the like while comparing both the visual field of the microscope and the MRI image. Furthermore, a system called Picture in Picture, which displays an MRI image by superimposing it on a part of the field of view of a microscope, is also used, and the MRI image is used.

[0004]

However, since the positional relationship between the field-of-view image viewed through a microscope and the MRI image is not always clear, it is difficult to confirm the site of interest in the MRI image with the field-of-view image. The usability of was not good.
The same applies when an MRI image is displayed on a part of the visual field image of the microscope.

An object of the present invention is to obtain a positional relationship between a field-of-view image of a microscope and an MRI image to improve usability of the MRI image in medical treatment using the microscope.

[0006]

In order to solve the above-mentioned problems, a medical support system of the present invention provides a magnetic resonance imaging apparatus having image display means for displaying a tomographic image of a subject, and the subject is observed. And a mark display means for displaying a mark by superimposing a mark on the position of the visual field image of the microscope corresponding to the position of the marked portion marked on the image displayed by the image display means. The means changes the display mode of the mark according to the difference in distance between the mark and the visual field image in the depth direction of the subject.

As described above, the mark marked on the region of interest on the MRI image is superposed and displayed on the corresponding position of the visual field image of the microscope as a display mode corresponding to the distance in the depth direction of the subject. While concentrating on the visual field image of the microscope, the position of the region of interest and the distance in the depth direction can be recognized, and the usability of the MRI image is improved.

Further, when the position of the microscope moves according to use, the mutual relation of coordinates may be obtained and the coordinates may be converted as follows.

That is, a tomographic image displayed on the image display means of the magnetic resonance imaging apparatus is equipped with a magnetic resonance imaging apparatus for taking a magnetic resonance image of a predetermined region of the object and a microscope for observing the object. Input means for setting a mark representing a region of interest, an optical rangefinder for detecting a coordinate reference point provided on the magnetic resonance imaging apparatus and a coordinate reference point provided on the microscope, and a focal length and a magnification of the microscope. Relative position between the coordinate system of the visual field image and the coordinate system of the image in which the mark is set based on detection means for detecting, detection information output from the optical rangefinder and detection information output from the detection means. And a mark display means for displaying the mark by superimposing the mark on the visual field image of the microscope. In the mark display means, the computing means includes the visual field image and the mark. And displaying superimposed on the field image based on the mark display mode is changed in accordance with the distance to calculate the distance of the object depth direction to the relative position of the.

In this way, the coordinate reference points provided on both the MRI apparatus and the microscope are detected by the optical rangefinder,
The detection information is input to the arithmetic device. The arithmetic device calculates the relationship between the MRI coordinate and the microscope coordinate based on the detection information. That is, coordinate conversion becomes possible. Then, the position of the field of view image of the microscope in the coordinate system of the microscope is obtained from the detection information of the focal length and magnification of the microscope, so the relationship between the coordinate system provided in the field of view image and the coordinate system of the microscope can be calculated, and coordinate conversion is performed. You can Therefore, by summarizing the calculated relationships described above, the relationship between the coordinate system of the visual field image and the MRI coordinate system can be calculated, and thus the coordinate conversion can be performed.

Further, the MRI apparatus picks up a magnetic resonance image of a predetermined region of the subject, and the MRI image marking the region of interest can be grasped by MRI coordinates. Therefore, the coordinate system and MRI provided on the marked MRI image
The relationship with the coordinate system can be calculated and the coordinates can be converted. From these calculated values, the calculation means further calculates the marked MRI.
Since the relationship between the coordinate system of the image and the coordinate system of the field of view of the microscope can be calculated, the mark in the display mode changed according to the distance in the depth direction of the subject between the field image and the mark is placed at the corresponding position of the field image. The marks can be displayed in an overlapping manner by the mark display means.

By the way, when the microscope is fixed, the relationship between the MRI coordinate system and the microscope coordinate system can be obtained in advance, so that the optical rangefinder is unnecessary.

Further, in the display mode in which the visual field image and the mark are changed depending on the distance in the depth direction of the subject, it is preferable to display the distance in the depth direction as well.

Further, it is preferable that the mark at a position not displayed in the field image is displayed so as to be superimposed on the field image of the microscope in a display mode showing the direction in which the mark is located. By making such a display, the position of the region of interest can be recognized, and the usability of the MRI apparatus is further improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of a configuration of one embodiment according to the present invention, FIG. 2 is an operation explanatory diagram of one embodiment according to the present invention, and FIG. 3 is a diagram showing a procedure of operation of one embodiment according to the present invention. FIG. 4 is a block diagram showing the overall configuration of a magnetic resonance imaging apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the medical support system according to the present embodiment mainly comprises an MRI apparatus 1 (magnetic resonance imaging apparatus), a microscope 3, an optical range finder 5, a computing means 7, a detecting means 9 and a marking display. It is composed of means 11. MR
The I device 1 is a device that captures a magnetic resonance image of a predetermined region of a subject, reconstructs the image, and displays the image on a monitor or the like. The microscope 3 is an instrument that is used in a medical field and is used to magnify and observe a region of a subject such as treatment or surgery. The optical range finder 5 is a device that measures the angle of the light beam from the target object that is incident on the two windows to optically measure the distance to the target object.
The light rays from the reference coordinate points provided on both the MRI apparatus 1 and the microscope 5 are received and measured. The arithmetic device 7 is a device that calculates the relationship between the reference coordinate points based on the detection information from the optical rangefinder 5 connected by a communication line and performs coordinate conversion. The detecting means 9 detects the focal length and magnification of the microscope, and inputs the detected value to the calculating means 7 connected by a communication line. The MRI apparatus 1 and the calculation means 7 are connected by a communication line, and the information of the marked MRI image is input from the MRI apparatus 1 to the calculation means 7. Marking display means 11
Calculates the mark input and set in the MRI image by the calculating means 7
It is displayed on the visual field image of the microscope 3 on the basis of the calculated information from, and is connected to the computing means 7 by a communication line.

Further, as shown in FIG. 4, the magnetic resonance imaging apparatus 1 (MRI apparatus) of this embodiment has a static magnetic field generation circuit 3
1, gradient magnetic field generation system 32, transmission system 33, reception system 34, signal processing system 35, sequencer 36, and central processing unit (C
PU) 37 and the like. Static magnetic field generation circuit 31
Is for generating a uniform static magnetic field in the space in which the subject 39 is placed. The direction of the static magnetic field is normally 3
9 is a body axis direction or a direction orthogonal to the body axis. The static magnetic field generation circuit 31 is formed by using a permanent magnet system, a normal conduction system, or a superconductivity system. The gradient magnetic field generation system 32 includes a gradient magnetic field coil 40 that generates a gradient magnetic field in three orthogonal (X, Y, Z) directions, and the gradient magnetic field coil 4 thereof.
It has a gradient magnetic field power supply 41 for supplying a drive current of 0. The gradient magnetic field power supply 41 follows a command from the sequencer 36 to generate a gradient magnetic field G in three orthogonal (X, Y, Z) directions.
s, Gp, and Gr are applied to the subject 39. The slice plane of the tomographic image can be set depending on how the gradient magnetic field is applied. Sequencer 36 is CPU 37
Of the gradient magnetic field generation system 32 and the transmission system 3 according to an imaging sequence called a pulse sequence.
3. Sending a command to the receiving system 34 and the like to execute the control necessary for capturing a tomographic image.

The transmission system 33 irradiates a high-frequency magnetic field pulse with a high-frequency magnetic field pulse in order to cause nuclear magnetic resonance in atomic nuclei constituting the biological tissue of the subject 39, and includes a high-frequency oscillator (synthesizer) 32 and a modulator 33. A high frequency amplifier 34 and a high frequency irradiation coil 35 are provided. Then, according to the instruction from the sequencer 36, the transmission system 33 amplitude-modulates the high-frequency magnetic field pulse output from the high-frequency oscillator 42 by the modulator 43, further amplifies it by the high-frequency amplifier 44, and then supplies the high-frequency irradiation coil 45 with the high-frequency irradiation coil 45. A magnetic field pulse (RF pulse) is applied to the subject 39.

The receiving system 34 detects a magnetic resonance signal such as an echo signal emitted by nuclear magnetic resonance of atomic nuclei of the living tissue of the subject 39, and includes a high frequency receiving coil 46 on the receiving side, an amplifier 47, and a quadrature phase. It has a detector 48 and an A / D converter 49. The magnetic resonance signal received by the high frequency receiving coil 46 is amplified by the amplifier 47,
After being detected by the quadrature detector 48, the A / D converter 49
Is converted into digital signal measurement data. The two series of measurement data sampled by the quadrature detector 48 with the phase shifted by 90 ° at the timing controlled by the sequencer 36 are sent to the signal processing system 35. In the present embodiment, the high frequency irradiation coil 45 and the high frequency reception coil 46 are provided separately, but they may be used for both transmission and reception.

The signal processing system 35 includes a CPU 37 and a ROM 5
0, a RAM 51, a magneto-optical disk 52, a display 53 such as a CRT, and a magnetic disk 54. The CPU 37 performs an image reconstruction process including a Fourier transform process on the input measurement data, creates a signal intensity distribution of an arbitrary cross section or an image subjected to a predetermined process, and displays it as a tomographic image on the display 53. ing. The ROM 50 stores a program for performing image analysis processing and measurement over time, invariant parameters used for the execution, and the like. The RAM 51 temporarily stores the measurement parameter used in the previous measurement, the echo signal detected by the reception system 34, and the image used for setting the region of interest, and also stores the parameter for setting the region of interest. The magneto-optical disk 52 and the magnetic disk 54 are the CPU 37.
The data of the image reconstructed by is recorded. The display 53 includes a magneto-optical disk 52 and a magnetic disk 54.
The image data stored in is visualized and displayed as a tomographic image.

The operation section 38 is for inputting control information of processing executed in the signal processing system, and is constituted by, for example, a trackball or a mouse 55 and a keyboard 56.

Next, the operation and features of this embodiment will be described with reference to FIGS. The coordinate reference point 13 provided in the MRI apparatus 1 of FIG. 2 is composed of a plurality of light emitting diodes, and the light rays emitted from these light emitting diodes are divided into two.
The optical rangefinder 5 of the eye receives the light and measures the distance. The number of light emitting diodes is determined by the coordinate system (x, y,
z) and the coordinate system (X, Y, Z) of the optical range finder 5 are coordinated so as to obtain necessary detection information for coordinate conversion. The optical distance meter 5 and the calculation means 7 are connected by a signal line, and the detection information detected by the optical distance meter 5 is input to the calculation means 7. As shown in step S1 of FIG. 3, the arithmetic unit 7 calculates the MRI coordinate system (x,
The relationship between (y, z) and the coordinate system (X, Y, Z) of the optical distance meter 5 is calculated, and the coordinate conversion can be performed. The positional relationship between the coordinate system (x, y, z) of the MRI apparatus 1 and the coordinate reference point 13 provided in the MRI apparatus 1 is calculated in advance.

Next, the optical rangefinder 5 receives the light beam from the light emitting diode of the reference coordinate point 15 provided on the microscope 3 and inputs the detection information to the calculating means 7. The number of light emitting diodes at the reference coordinate point 15 is determined by the coordinate system (X, Y, Z) of the optical distance meter 5 and the coordinate system (X ′,
Y ′, Z ′) and the number of pieces of detection information necessary for coordinate conversion can be acquired. For example, considering the inclination and rotation which are the degrees of freedom of movement of the microscope 3, at least three light emitting diodes are required. Optical distance meter 5
The detection information detected in (1) is input to the calculation means 7 via a communication line. As shown in step S2 of FIG. 3, the calculation means 7 determines the optical rangefinder 5 based on the input detection information.
Coordinate system (X, Y, Z) and microscope coordinate system (X ',
Y ', Z') is calculated, and coordinate conversion becomes possible. The positional relationship between the coordinate system (X ′, Y ′, Z ′) of the microscope and the reference coordinate point 15 provided on the microscope 3 is calculated in advance.

Then, as shown in step 3 of FIG.
The calculation means 7 can calculate the relationship between the MRI coordinate system (x, y, z) and the microscope coordinate system (X ', Y', Z ') based on the calculation results of step 1 and step 2, and coordinate conversion is performed. Is possible.

Next, the detecting means 9 in FIG. 2 detects the focal length and the magnification of the microscope 3, and inputs the detection information to the calculating means 7 via a communication line. By detecting the focal length, the distance between the microscope and the visual field image of the microscope can be obtained. Further, by calculating the magnification of the microscope, the calculation means 7
As shown in step S4 of FIG. 3, the relationship between the coordinate system (X ″, Y ″, Z ″) provided in the microscope field image and the microscope coordinate system (X ′, Y ′, Z ′) can be calculated. The coordinate conversion can be performed The detection means 9 may be provided in the vicinity of the microscope 3 or may be provided inside the microscope 3.

Next, as shown in step S5 of FIG.
The calculation means 7 calculates the relationship between the MRI coordinate system (x, y, z) and the coordinate system (X ″, Y ″, Z ″) provided in the field image of the microscope from the calculation results of step 3 and step 4. You can
Coordinate conversion is possible.

On the other hand, the MRI apparatus 1 displays an MRI image 17 showing a tomographic image by image reconstruction on the display. The operator or the like marks the tumorous part or the important part to be excised, which appears on the MRI image, with the input means 19 such as a mouse. As the mark, there are a mark in a display mode showing a portion of a dot, a mark showing a region of interest with a closed curve and the like. As shown in FIG. 4, the mark input means 19 may be the trackball of the operation unit 38, the mouse 55, the keyboard 56, or the like, but is not limited thereto. Further, the computing means 7 is an independent PC (personal computer).
Or the like, or C of the MRI apparatus 1 shown in FIG.
It may be PU37. In any case, the MRI apparatus 1
The information regarding the marked MRI image is input from the to the calculating means 7.

The calculating means 7 calculates the position of the mark on the MRI image in the coordinate system (x ', y', z ') provided on the marked MRI image, as shown in step S6 of FIG. .

Further, the MRI apparatus 1 is for picking up a magnetic resonance image of a predetermined portion of the subject, and the step S7 in FIG.
As shown in FIG. 3, the calculation means 7 has an MRI coordinate system (x, y,
From the position information of the MRI image in z), the relationship between the coordinate system (x ', y', z ') provided in the MRI image and the MRI coordinate system (x, y, z) can be calculated, and the coordinate conversion can be performed. Become.

Next, in step S8 of FIG. 3, the calculating means 7 causes the coordinate system (X ", Y", Z ") of the microscope field image calculated in step S5 and the MRI coordinate system (x, y, z). )
And the relationship between the coordinate system (x ', y', z ') provided in the MRI image calculated in step S7 and the MRI coordinate system (x, y, z), the coordinate system (x' , Y ',
z ') and the coordinate system of the field of view of the microscope (X ", Y", Z ")
The relationship with can be calculated and the coordinates can be converted.

Therefore, the position of the mark set on the target region is determined by the coordinate system (x ',
y ′, z ′), the coordinates can be converted into the coordinate system of the view image (X ″, Y ″, Z ″), and the mark can be converted into the coordinate system of the view image (X ″, Y ″, Z ″). Can be calculated by As shown in step S9, the calculation means 7 calculates the distance from the surface of the visual field image to the mark in the depth direction of the subject, and displays the mark according to the length of the distance, for example, the color according to the distance. Information to be displayed at the corresponding position of the visual field image is sent to the marking display means 11. The corresponding position of the view image is
The magnification detected in step S4 is also taken into consideration.

The mark display means 11 shown in FIG.
The information regarding the mark from (1), that is, the display information changed according to the depth direction and the display information at the corresponding position of the field image is input, and displayed on the field image of the microscope 3 in an overlapping manner. The mark display means 11 mainly comprises a display and a half mirror. The half mirror provided inside the microscope 3 reflects the image of the mark displayed on the display provided on the body of the microscope 3 and transmits the visual field image so that the marks can be displayed in an overlapping manner. There is. In the present embodiment, the microscope 3 uses an optical microscope, but when the microscope is a so-called digital microscope, the mark display means 11 means an image synthesizing device.

As described above, since the mark of the display mode in which the position of the region of interest marked on the MRI image is changed according to the distance in the depth direction of the subject is displayed on the visual field image, the visual field image of the microscope is displayed. While keeping a close eye on the user, the distance to the region of interest can be grasped and the usability of the MRI image is improved. For example, FIGS. 5A and 5B are diagrams showing the MRI images 61 and 63, in which the mark 6 is placed on the attention site of the MRI images 61 and 63.
Set 5, 67. 6A and 6B are views showing field images 69 and 71 of the microscope, in which marks 65 and 67 set in the MRI image change colors according to the distance in the depth direction of the subject. The visual field images 69 and 71 are superimposed and displayed.

Next, a comparison will be made with the prior art. FIG. 7 is a cross section (a), a vertical section (b), in which the position of the surgical instrument is detected.
It is the figure which showed the MRI image of (c). The position 77 of the surgical instrument is indicated by the intersection of the meridian and the latitude line. However, the positional relationship with the field of view of the microscope was not always clear.
FIG. 8 shows the MRI images of the horizontal section (a), vertical section (b), and (c) of FIG. 7 displayed in the visual field image 79 of the microscope. Although the position 77 of the surgical instrument 81 is displayed, the positional relationship between the visual field image of the microscope and the MRI image, that is, the distance between the visual field image and the site of interest is not always clear. As described above, conventionally, usability of MRI images has not always been good.

Further, in the present embodiment, although the mark of the display mode is changed according to the distance in the depth direction of the subject, the numerical value of the distance calculated by the calculating means can be displayed together.

Further, the mark at a position that cannot be displayed in an overlapping manner on the field image of the microscope may be a mark for indicating the position, for example, an arrow mark. The arrow may be colored according to the distance in the depth direction.

In this embodiment, the microscope 3 is movable, but when it is fixed, the relationship between the microscope and the MRI coordinates is calculated in advance, so an optical measuring device is not necessary. Become.

[0038]

According to the present invention, the visual field image of the microscope and the MR
By obtaining the positional relationship with the I image, it is possible to improve the usability of the MRI image in medical treatment using a microscope.

[Brief description of drawings]

FIG. 1 is a configuration conceptual diagram of an embodiment to which the present invention is applied.

FIG. 2 is an operation explanatory diagram of an embodiment to which the present invention is applied.

FIG. 3 is a diagram showing an operation procedure of an embodiment to which the present invention is applied.

FIG. 4 is a block diagram showing an overall configuration of a magnetic resonance imaging apparatus of one embodiment to which the present invention is applied.

FIG. 5 is a diagram showing diagrams (a) and (b) showing an MRI image.

FIG. 6 is a diagram showing views (a) and (b) showing a visual field image of a microscope.

FIG. 7 is a diagram showing views (a), (b), and (c) showing an MRI image.

FIG. 8 is a view in which an MRI image is superimposed and displayed on a visual field image of a microscope.

[Explanation of symbols]

1 MRI system (magnetic resonance imaging system) 3 microscope 5 Optical rangefinder 7 computing means 9 Detection means 11 Mark display means 13 coordinate reference points 15 coordinate reference points 17 MRI images 19 Input means

Claims (3)

[Claims] 1. A magnetic resonance imaging apparatus having image display means for displaying a tomographic image of a subject, a microscope for observing the subject, and a region of interest marked on the image displayed by the image display means. And a mark display means for displaying a mark by superimposing the mark on the position of the field image of the microscope in correspondence with the position of the mark, the mark display means according to the difference in the distance between the mark and the field image in the depth direction of the object. A medical support system characterized by different display modes of marks. 2. A magnetic resonance imaging apparatus for picking up a magnetic resonance image of a predetermined region of a subject, and a microscope for observing the subject, wherein a tomographic image displayed on an image display means of the magnetic resonance imaging apparatus is displayed. Input means for setting a mark representing a region of interest, an optical rangefinder for detecting a coordinate reference point provided on the magnetic resonance imaging apparatus and a coordinate reference point provided on the microscope, and a focal length and magnification of the microscope. Relative position between the coordinate system of the visual field image and the coordinate system of the image in which the mark is set based on the detection means for detecting and the detection information output from the optical rangefinder and the detection information output from the detection means. Computation means for calculating, and mark display means for superimposing and displaying the mark on the visual field image of the microscope, the mark display means, the computing means, the visual field image and the mark Medical support system that displays superimposed on the field image based on the mark display mode is changed in accordance with the distance to calculate the distance of the object depth direction to said relative position. 3. The mark display means according to claim 1, wherein the mark at a position not displayed on the visual field image is superimposed on the visual field image in a display mode showing a direction in which the mark is located. Characteristic medical support system.