JP6739589B1 - Magnetic resonance imaging apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MRI apparatus capable of positioning a subject at an optimum position. An MRI apparatus has a cradle (31) for supporting a subject (10) and an inner wall (8) defining a bore (6) for receiving a chest and a shoulder of the subject (10), the inner wall surface (82a) contacting the shoulder. A magnet 2 having an inner wall and an inner wall 9 defining a bore 7 for receiving the head of the subject 10, and a camera for acquiring an image in the bore using an optical lens and outputting a signal representing the image. And an image generation unit that generates an image in which the shape of the surface of the inner wall is visually emphasized based on a signal obtained from the camera, and a display unit 12 that displays the image. [Selection diagram] Fig. 22

Description

The present invention relates to a magnetic resonance imaging apparatus suitable for imaging the head of a subject, and a program applied to the magnetic resonance imaging apparatus.

An MRI (Magnetic Resonance Imaging) apparatus is known as an apparatus capable of non-invasively acquiring an image of the inside of the body of a subject. Since the MRI apparatus can acquire an image of a subject without using X-rays, there is no fear of being exposed to the subject and it is used in various medical institutions.

In recent years, human brain function data has begun to be applied to product development and evaluation in various industrial fields. In particular, fMRI, which can examine the activity state of the whole brain with high resolution, has attracted attention as a measurement method suitable for examining human brain function. From such a background, a head-only MRI apparatus has been developed (see Patent Document 1).

JP 8-168476 A

Patent Document 1 discloses a magnetic resonance imaging magnet 10 dedicated to the head. In the MRI apparatus for the whole body, a bore having a substantially constant width is formed, but the magnet 10 of Patent Document 1 has bores 20 and 22 having different widths. As shown in FIG. 1 of Patent Document 1, the bore 20 has a wide opening diameter so that the shoulder of the subject can enter, but the bore 22 that receives the head has a narrow opening diameter.

When the subject is imaged using the magnetic resonance imaging magnet 10 described in Patent Document 1, the operator uses the region 44 (where the brain (head) is suitable for imaging from the viewpoint of magnetic field homogeneity and sensitivity of transmission RF. It is desired to drive the subject's head into the bore 22 so that it is positioned within (dashed line). On the other hand, depending on the physique of the subject, even if the shoulder 40 of the subject is brought into contact with the inner wall of the boundary between the bore 20 and the bore 22, the head of the subject may not be sufficiently sent to the region 44. .. In such a case, the operator needs to move the cradle so that the shoulder 40 of the subject is pressed against the inner wall of the boundary portion between the bore 20 and the bore 22.
However, if the shoulder portion 40 of the subject is strongly pressed against the inner wall of the boundary portion between the bore 20 and the bore 22, the physical burden on the subject increases. Therefore, the operator needs to move the cradle in consideration of the homogeneity of the magnetic field and the sensitivity of the transmission RF and the viewpoint of the physical burden on the subject.

However, the head receiving bore 22 has a narrower inner diameter than the bore 20. Therefore, when the operator tries to view the narrow bore 22 from the outside of the magnet 10 while moving the cradle, the subject blocks the bore 22 as the subject's head approaches the bore 22. Therefore, it is difficult for the operator to visually judge how close the shoulder 40 of the subject is to the bore 20, and it may be difficult to position the cradle at the optimum position.

Therefore, it is desired to provide an MRI apparatus that can position a subject at an optimum position.

A first aspect of the present invention is a cradle that supports a subject,
A first inner wall defining a first bore for receiving the chest and shoulders of the subject, the first inner wall having an inner wall surface with which the shoulder contacts, and a first inner wall for receiving the head of the subject A magnet having a second inner wall defining two bores;
Image acquisition means for acquiring an image in the first bore using an optical lens and outputting a signal representative of the image;
Image generation means for generating an image in which the shape of the surface of the first inner wall is visually enhanced based on the signal obtained from the image acquisition means;
It is a magnetic resonance imaging apparatus having a display unit for displaying the image.

A second aspect of the present invention is to provide a cradle for supporting a subject,
A first inner wall defining a first bore for receiving the chest and shoulders of the subject, the first inner wall having an inner wall surface with which the shoulder contacts, and a first inner wall for receiving the head of the subject A magnet having a second inner wall defining two bores;
Image acquisition means for acquiring an image in the first bore using an optical lens and outputting a signal representative of the image;
And a control means for controlling the movement of the cradle,
The control means is
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder of the subject has reached the vicinity of the inner wall surface, and the shoulder of the subject has reached the vicinity of the inner wall surface. In the case of outputting a control signal for reducing the speed of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject contacts the inner wall surface, and when the shoulder portion of the subject contacts the inner wall surface, Determining whether or not it is necessary to press the shoulder portion of the sample against the inner wall surface,
When it is determined that the shoulder portion of the subject needs to be pressed against the inner wall surface, a control signal for moving the cradle is output so that the shoulder portion of the subject is pressed against the inner wall surface. Is a magnetic resonance imaging apparatus for performing.

A third aspect of the present invention is a first inner wall defining a first bore for receiving a chest and a shoulder of a subject, the first inner wall having an inner wall with which the shoulder contacts, and A magnet having a second inner wall defining a second bore for receiving the head of the subject and an image in the first bore are acquired using an optical lens and a signal representative of the image is output. An image acquisition means for, and a program applied to a magnetic resonance imaging apparatus having a display means for displaying the image,
It is a program for causing a computer to execute an image generation process for generating an image in which the shape of the surface of the first inner wall is visually emphasized based on a signal obtained from the image acquisition means.

A fourth aspect of the present invention is a cradle that supports a subject and a first inner wall that defines a first bore that receives the chest and shoulders of the subject, the inner wall being in contact with the shoulder. A magnet having a first inner wall having a second inner wall defining a second bore for receiving the subject's head, and an optical lens to obtain an image in the first bore. A program applied to a magnetic resonance imaging apparatus having an image acquisition unit for outputting a signal representing the image, and a control unit controlling the movement of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder of the subject has reached the vicinity of the inner wall surface, and the shoulder of the subject has reached the vicinity of the inner wall surface. In the case, a process of outputting a control signal for reducing the speed of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject contacts the inner wall surface, and when the shoulder portion of the subject contacts the inner wall surface, Processing to determine whether or not the shoulder portion of the sample needs to be pressed against the inner wall surface, and, if it is determined that the shoulder portion of the subject needs to be pressed against the inner wall surface, the shoulder portion of the subject is It is a program for causing a computer to execute a process of outputting a control signal for moving the cradle so as to be pressed against the inner wall surface.

A fifth aspect of the present invention is a first inner wall defining a first bore for receiving a chest and a shoulder of the subject, the first inner wall having an inner wall with which the shoulder contacts, A magnet having a second inner wall defining a second bore for receiving the subject's head and an image in the first bore is acquired using an optical lens, and a signal representing the image is output. And an image generating unit for generating an image in which the shape of the surface of the first inner wall is visually emphasized based on a signal obtained from the image acquiring unit, and the image is displayed. A non-transitory computer-readable recording medium, which is provided in a magnetic resonance imaging apparatus having a display means and stores one or more instructions executable by a processor, The instructions, when executed by the processor,
Receiving the signal output by the image acquisition means,
Generating an image in which the shape of the first inner wall is emphasized based on the signal; performing an operation including outputting an image signal representing the image in which the shape of the inner wall is emphasized to the display means; It is a temporary computer-readable storage medium.

A sixth aspect of the present invention is a cradle that supports a subject and a first inner wall that defines a first bore that receives the chest and shoulder of the subject, the inner wall being in contact with the shoulder. A magnet having a first inner wall having a second inner wall defining a second bore for receiving the subject's head, and an optical lens to obtain an image in the first bore. A magnetic resonance imaging apparatus having image acquisition means for outputting a signal representing the image and control means for controlling movement of the cradle, and storing one or more instructions executable by a processor. A non-transitory computer-readable recording medium, wherein the one or more instructions are executed by the processor,
Receiving a signal output by the image acquisition means, based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject has reached the vicinity of the inner wall surface, the shoulder of the subject Outputting a control signal for reducing the speed of the cradle when the section reaches the vicinity of the inner wall surface,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject contacts the inner wall surface, and when the shoulder portion of the subject contacts the inner wall surface, To determine whether or not it is necessary to press the shoulder portion of the sample against the inner wall surface, and, if it is determined that the shoulder portion of the subject needs to be pressed against the inner wall surface, the shoulder portion of the subject is A non-transitory computer-readable storage medium that performs an operation including outputting a control signal for moving the cradle so as to be pressed against the inner wall surface.

The magnetic resonance imaging apparatus of one aspect of the present invention generates an image in which the shape of the surface of the inner wall of the bore is visually emphasized based on the signal obtained from the image acquisition means, and displays this image on the display unit. doing. Therefore, the operator can visually recognize the difference between the shoulder and the inner wall of the subject by looking at the image displayed on the display unit, and the subject is positioned at the optimum position. You can move the cradle like so.

Another embodiment of the magnetic resonance imaging apparatus of the present invention, based on the signal obtained from the image acquisition means, determines whether the shoulder portion of the subject has reached the vicinity of the inner wall surface, When the shoulder of the sample reaches the vicinity of the inner wall surface, a control signal for reducing the speed of the cradle is output. Therefore, when the subject is moved to the bore, the shoulder of the subject can be brought into contact with the inner wall surface without applying an unreasonable force to the shoulder of the subject. Further, the magnetic resonance imaging apparatus of the other form, when it is determined that it is necessary to press the shoulder portion of the subject against the inner wall surface, so that the shoulder portion of the subject is pressed against the inner wall surface, A control signal for moving the cradle is output. Therefore, if it is not possible to position the head of the subject in a region where the static magnetic field is highly uniform simply by bringing the shoulder of the subject into contact with the inner wall surface, press the shoulder of the subject against the inner wall surface. The head of the subject can be brought close to a region where the static magnetic field is highly uniform.

It is a block diagram of the MRI apparatus 1 of a 1st form. It is an external view of the magnet 2 and the table 3. FIG. 6 is a cross-sectional view taken along the yz plane of the magnet 2 and the table 3. It is a sectional view taken along the zx plane of the magnet 2. It is explanatory drawing of the inner walls 8 and 9. It is a perspective view of the table 3. It is a top view of the cradle 31. It is a perspective view of the cradle 31. It is a figure which shows a mode that the cradle 31 was moved to the z direction. FIG. 6 is a diagram showing a state in which a receiving coil 35 is attached to a recess 313 of the cradle 31. FIG. 3 is a diagram showing a state in which a subject 10 is laid down on a cradle 31. FIG. 7 is a diagram showing a state in which the cradle 31 is moved so that the head of the subject 10 is positioned in the bore 7 of the magnet 2. 3 is an explanatory diagram of a camera 11 and a display unit 12. FIG. It is a figure which shows roughly an example of the image which the display part 12 displays. 3 is a diagram showing a state in which the subject 10 lies on a cradle 31. FIG. It is a figure which shows the functional block of the control unit 24. FIG. 6 is a diagram showing an example of a flow of a method of generating an image displayed on the display unit 12. It is explanatory drawing of the acquisition method of the image data D1-Dn for learning. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved only (DELTA)z1. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z2. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z3. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z4. It is a figure which shows the functional block of the control unit 24. It is explanatory drawing of the acquisition method of the image data E1-En for learning. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved only (DELTA)z1. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z2. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z4. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved from z4 by (DELTA)zd. It is explanatory drawing of the acquisition method of the image data F1-Fn for learning. It is explanatory drawing of the MRI apparatus in the state which the cradle 31 moved by (DELTA)z2.

Hereinafter, modes for carrying out the invention will be described, but the invention is not limited to the following modes.

(1) First Mode FIG. 1 is a block diagram of an MRI apparatus 1 of the first mode.
The MRI apparatus 1 has a magnet 2 and a table 3. The magnet 2 is equipped with various coils including a superconducting coil, a gradient coil, and an RF coil. In FIG. 1, the gradient coil 15 and the RF coil 16 are schematically shown as the coils. The MRI apparatus 1 reconstructs an image of the head of the subject 10 based on the MR signal received by the receiving coil 35.

The MRI apparatus 1 has a T/R switch 20, an RF driver unit 21, a gradient coil driver unit 22, a data collection unit 23, a control unit 24, a data processing unit 25, an operation console unit 26, and a display unit 27. ..

The T/R switch 20 is configured to operate in a reception mode and a transmission mode. The T/R switch 20 selectively couples the reception coil 35 and the RF coil 16 to the data acquisition unit 23 in the reception mode, and selectively transmits the reception coil 35 and the RF coil 16 to the RF driver unit 21 in the transmission mode. Join.

The T/R switch 20 transmits the control signal from the RF driver unit 21 to the RF coil 16 and the MR signal received by the receiving coil 35 to the data acquisition unit 23.

The RF driver unit 21 is electrically coupled to the coil through the T/R switch 20 and drives the coil.

The gradient coil driver unit 22 drives the gradient coil 15 based on the control signal received from the control unit 24.
The data acquisition unit 23 acquires the MR signal received by the reception coil 35.

The control unit 24 has a computer and a recording medium in which a program executed by the computer is recorded. When the program is executed by the computer, each part of the MRI apparatus executes an operation corresponding to a predetermined scan. As the recording medium, for example, a read only memory (ROM), a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a non-volatile memory card can be used.

The control unit 24 processes an operation signal input from the operation console unit 32 and outputs a control signal to the table 3, the RF driver unit 21, the gradient coil driver unit 22, and the data acquisition unit 23 to control the operation signal. The control unit 24 also controls the data processing unit 25 and the display unit 27 based on the operation signal from the operation console unit 26.

The data processing unit 25 has a computer and a recording medium (for example, a hard disk) in which a program executed by the computer is recorded. The data processing unit 25 is electrically coupled to the control unit 24. The data processing unit 25 executes data processing based on the control signal received from the control unit 24.

The operation console unit 26 includes user input devices such as a keyboard and a mouse. The operation console unit 26 is operated by an operator, whereby, for example, an image protocol is input and slices are set. The image protocol and slice-related data input by the operation console unit 26 are transmitted to the control unit 24.

The display unit 27 includes a graphical display device (for example, a computer screen), and displays various images on the graphical display device based on a control signal from the control unit 24.

FIG. 2 is an external view of the magnet 2 and the table 3.
The magnet 2 has an enclosure 5 that covers each component inside the magnet 2. The enclosure 5 comprises bores 6 and 7 for allowing the subject 10 to be received.

3 is a sectional view taken along the yz plane of the magnet 2 and the table 3, and FIG. 4 is a sectional view taken along the zx plane of the magnet 2.
The enclosure 5 has an inner wall 8 for defining a bore 6 and an inner wall 9 for defining a bore 7.

FIG. 5 is an explanatory diagram of the inner walls 8 and 9.
The inner wall 8 is formed to define a bore 6 that receives the chest and shoulders of the subject 10. The inner wall 8 can be roughly divided into two parts, namely inner wall portions 81 and 82. The inner wall portion 81 is located on the front surface 2a side of the magnet 2, and the inner wall portion 82 is located on the inner wall 9 side. The inner wall portion 81 and the inner wall portion 82 are integrally formed. The inner wall portion 82 is formed in a substantially tapered shape that tapers from the inner wall portion 81 toward the inner wall 9. The inner wall surface 82a of the inner wall portion 82 is a surface that can be used as a surface against which the shoulder portion of the subject 10 is pressed. The inner wall surface 82a will be described later.

The inner wall 9 is formed so as to define the bore 7 that receives the head of the subject 10. The bore 7 is formed by the inner walls 8 and 9 so as to have a width narrower than that of the bore 6.

FIG. 6 is a perspective view of the table 3.
The table 3 has a cradle 31 that supports the subject 10 and a cradle support 32 that supports the cradle 31.

FIG. 7 is a plan view of the cradle 31, and FIG. 8 is a perspective view of the cradle 31.
The cradle 31 has a first support portion 311 and a second support portion 312. The first support portion 311 is a portion that is received in the bore 6 (see FIG. 4 ), while the second support portion 312 is a portion that is received in the bore 7 (see FIG. 4 ), which is narrower than the bore 6. .. Therefore, the second support portion 312 is formed such that the width w2 of the second support portion 312 is narrower than the width w1 of the first support portion 311.

The cradle 31 is supported by the cradle support 32 so as to be movable in the z direction with respect to the cradle support 32 (see FIG. 6). FIG. 9 shows a state in which the cradle 31 is moved in the z direction. By moving the cradle 31, the subject 10 can be moved to the bores 6 and 7 of the magnet 2.

Further, as shown in FIGS. 7 and 8, a recess 313 with which the receiving coil 35 is engaged is formed on the surface of the second support portion 312. FIG. 10 is a diagram showing a state where the receiving coil 35 is attached to the recess 313 of the cradle 31. The recess 313 allows the receiving coil 35 to be detachably attached to the second supporting portion 312.

FIG. 11 is a diagram showing a state in which the subject 10 is laid on the cradle 31.
When the subject 10 is imaged, the operator positions the head of the subject 10 on the receiving portion 35a of the receiving coil 35, and the torso and legs of the subject 10 are supported by the first support portion 311. Then, the subject 10 is laid on the cradle 31. Since the receiving coil 35 engages with the recess 313, the operator can easily install the receiving coil 35 in the cradle 31. After laying the subject 10 on the cradle 31, the operator moves the cradle 31 so that the head of the subject 10 is positioned in the bore 7 (see FIG. 4) of the magnet 2.

FIG. 12 is a diagram showing a state in which the cradle 31 is moved so that the head of the subject 10 is positioned in the bore 7 of the magnet 2.
The left side of FIG. 12 is a diagram showing a state before moving the cradle 31, and the right side of FIG. 12 is a diagram showing a state after moving the cradle 31.

When the cradle 31 is moved in the z direction, the receiving coil 35 passes through the bore 6 and enters the bore 7. The bore 7 is formed to have a size capable of receiving the receiving coil 35. Therefore, the head of the subject 10 can be positioned in the bore 7 with the receiving coil 35 attached to the head of the subject 10.

It should be noted that when the cradle 31 is moved, the shoulder of the subject 10 approaches the inner wall surface 82a. Therefore, the operator needs to move the cradle 31 while confirming the position of the shoulder of the subject with respect to the inner wall surface 82a. As a method for the operator to confirm the position of the shoulder of the subject with respect to the inner wall surface 82a, a method may be considered in which the operator looks into the bores 6 and 7 from the outside of the magnet 2 while moving the cradle 31.

However, the inner wall surface 82a is formed in a substantially tapered shape. Therefore, when the operator looks into the bores 6 and 7 from the outside of the magnet 2, as the subject 10 approaches the inner wall surface 82a, the subject 10 blocks the inner wall surface 82a, and the operator does not touch the inner wall surface 82a. There is a drawback that it is difficult to confirm the position of the shoulder of the subject.

Further, since the imaging site is the head (brain), the operator moves the cradle 31 so that the head of the subject 10 enters the imaging region 7a in which the uniformity of the static magnetic field is sufficiently ensured. It is important to let them do it. However, depending on the physique of the subject 10, even if the shoulder of the subject 10 is in contact with the inner wall surface 82a, the head of the subject 10 may not sufficiently enter the imaging region 7a. In such a case, the operator places the shoulder of the subject 10 on the inner wall surface 82a so that the head of the subject 10 enters the imaging region 7a (or is positioned as close as possible to the imaging region 7a). It is necessary to further move the cradle 31 in the z direction by a certain distance so as to be pressed, and feed the head of the subject 10 as far into the bore 7 as possible. However, as described above, in the method of looking into the bores 6 and 7 from the outside of the magnet 2, it is difficult to confirm the position of the shoulder portion of the subject 10 with respect to the inner wall surface 82a. When pressed against, it is difficult for the operator to judge how much the cradle 31 should be moved.

Therefore, in the first embodiment, the magnet 2 includes the camera 11 and the display unit 12 in order to deal with the above-mentioned drawbacks. FIG. 13 is an explanatory diagram of the camera 11 and the display unit 12.

The camera 11 is configured to use an optical lens to capture the images in the bores 6 and 7 and output a signal representative of the images. The camera 11 is fixed to the inner wall portion 82 of the inner wall 8. The camera 11 has a wide field of view so that not only the bore 6 but also a part of the bore 7 and a space outside the bore 6 are included in the field of view 11b. Therefore, in FIG. 13, the head of the subject 10 has not moved to the bore 6 yet, but the camera 11 can capture an image including the receiving coil 35 and the shoulder of the subject 10.

The magnet 2 has a display unit 12 on the front surface 2a. The display unit 12 displays the image captured by the camera 11.

The camera 11 captures an image within the field of view 11b and outputs a camera signal 11a (see FIG. 1) representing the captured image to the control unit 24. The control unit 24 performs a predetermined process on the camera signal 11a and outputs the camera signal 11a subjected to the predetermined process to the display unit 12 as an image signal. The display unit 12 displays an image corresponding to the image signal. FIG. 14 is a diagram schematically showing an example of an image displayed on the display unit 12. The right side of FIG. 14 is an example of an image displayed on the display unit 12 before the cradle 31 is moved, and the left side of FIG. 14 is an example of an image displayed on the display unit 12 after the cradle 31 is moved.

Therefore, since the operator can visually recognize the position of the shoulder of the subject 10 in the bore by looking at the display unit 12, the shoulder of the subject 10 can be moved while moving the cradle 31. The subject 10 can be moved into the bore until it contacts the inner wall surface 82a.

However, since the color of the inner walls 8 and 9 is typically a single color (for example, white), when the image acquired by the camera 11 is simply displayed on the display unit 12, the operator is displayed on the display unit 12. It may be difficult to recognize the difference between the bore 6 and the bore 7 even when looking at the image. In this case, the operator has a problem that it is difficult to visually recognize how close the shoulder of the subject 10 is to the inner wall surface 82a even when looking at the image displayed on the display unit 12. Therefore, in the present embodiment, the image acquired by the camera 11 is not simply displayed on the display unit 12, but the shape of the surface of the inner walls 8 and 9 is emphasized with respect to the image acquired by the camera 11. The emphasized image is displayed on the display unit 12. In the first embodiment, the operator moves the subject 10 into the bore while looking at the above image. Hereinafter, an example of a method in which the operator moves the subject 10 into the bore will be described.

The operator first lays the subject 10 on the cradle 31. FIG. 15 is a diagram showing a state in which the subject 10 lies on the cradle 31.

A plan view of the magnet 2 and the table 3 is shown on the right side of FIG. 15, and an image displayed by the display unit 12 provided on the front surface of the magnet 2 is schematically shown on the left side of FIG. There is. In this embodiment, an image (upper left) in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized is displayed as the image displayed by the display unit 12. An image (lower left) in which the shapes of the surfaces of the inner walls 8 and 9 are not emphasized is also shown.

The control unit 24 is configured to execute the following operations (a1)-(a3) so that the image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized is displayed on the display unit 12. ..
(A1) Receiving the camera signal 11a (a2) Generating an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized based on the camera signal 11a (a3) The shapes of the surfaces of the inner walls 8 and 9 are emphasized To output an image signal representing the displayed image to the display unit 12.

The storage medium of the control unit 24 has a non-transitory computer-readable recording medium in which one or more instructions for executing the above-described operations (a1)-(a3) are stored. The control unit 24 has a processor for reading a program in which the above-mentioned instruction is described from a recording medium and executing the instruction. The above operations (a1)-(a3) are executed by the processor executing the instructions. Therefore, as shown in FIG. 16, the control unit 24 has a reception unit 241, an image generation unit 242, and an output unit 243 as functional blocks. The receiving unit 241 receives the camera signal 11a. The image generation unit 242 generates an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized based on the camera signal 11a. The output unit 243 outputs to the display unit 12 an image signal representing an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized.

Hereinafter, an example of a method of generating an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized will be described.

FIG. 17 is a diagram illustrating an example of a flow of a method of generating an image displayed on the display unit 12.
The processor of the control unit 24 executes the instructions stored in the recording medium so that the operations of steps ST11 to ST14 are executed. Hereinafter, each step will be described in order.

In step ST11, the receiver 241 (see FIG. 16) of the control unit 24 receives the camera signal 11a. Then, the image generator 242 (see FIG. 16) of the control unit 24 detects the shoulder of the subject 10 based on the received camera signal 11a. The storage medium of the control unit 24 stores a program for executing a process of detecting the shoulder of the subject 10 based on the camera signal 11a. This program can be created based on the learning result by learning the image data necessary for detecting the shoulder of the subject 10 by the computer of the control unit 24 or the data processing unit 25, for example. The image data to be learned can be acquired as follows, for example.

First, a person actually sleeps on the cradle 31 with the receiving coil 35 attached, and while moving the cradle 31 toward the bore 7, the image data D1 to Dn of the camera 11 are acquired. FIG. 18 is an explanatory diagram of a method of acquiring the image data D1 to Dn. FIG. 18 shows that the cradle 31 is located at the home position z0. The image data D1 to Dn moves the cradle 31 from the home position z0 by a distance Δz required to bring a human shoulder into contact with the inner wall surface 82a, and the camera 11 moves while the cradle 31 moves by Δz. It is a series of image data acquired in. Therefore, a series of image data D1 to Dn can be acquired for one person. Further, the operation of changing the person sleeping on the cradle 31 to another person and acquiring the image data D1 to Dn is repeated. As a result, it is possible to acquire image data while the cradle 31 is moving, for people of different physiques.

When the image data to be learned is acquired, the image data acquired by the computer of the control unit 24 or the data processing unit 25 is learned. The computer of the control unit 24 or the data processing unit 25 learns, for example, the position of the receiving coil 35 with respect to the inner wall surface of the bore, the position of the shoulder with respect to the receiving coil 35, the shape of the surface of the shoulder, and the like. Based on these learning results, it is determined whether or not a human shoulder exists in the field of view 11b (see FIG. 13) of the camera 11, and if the human shoulder exists, the position of the shoulder is determined. It is possible to create a program (source code) for specifying the position information indicating the. The program created in this way is recorded in the storage medium of the control unit 24.

In the first embodiment, the field of view 11b of the camera 11 is wide, and the area in front of the magnet 2 is also included in the field of view 11b (see FIG. 13). Therefore, when the subject 10 lies on the cradle 31, the shoulder 11 of the subject 10 is included in the imaging field of view 11b of the camera 11. Therefore, the image generation unit 242 can execute the process of specifying the position of the shoulder of the subject 10 based on the camera signal 11a output from the camera 11.

In step ST12, the image generation unit 242 executes a process for specifying the color of the shoulder based on the camera signal 11a. Here, the shoulder is assumed to be green.

In step ST13, the image generation unit 242 executes a process for specifying the complementary color of the shoulder color. Here, since the shoulder portion is green, red, which is a complementary color of green, is specified as the complementary color of the shoulder portion.

In step ST14, the image generation unit 242 first executes a process for specifying the signal portion representing the inner walls 8 and 9 of the bore in the camera signal 11a. Unlike the cradle 31, the inner walls 8 and 9 of the bore remain stationary without moving. Therefore, the range in which the inner walls 8 and 9 of the bore appear is fixed with respect to the photographing field 11b of the camera 11. Therefore, the image generation unit 242 can identify the signal portion representing the inner walls 8 and 9 of the bore in the camera signal 11a.

Next, the image generation unit 242 performs a process of emphasizing the shape of the surface of the inner walls 8 and 9 for the signal portion representing the inner walls 8 and 9 of the camera signal 11a, and the colors of the inner walls 8 and 9 as shoulders. And a process of converting the color to the complementary color. As an example of the shape enhancement processing, shading or shading can be added according to the shape of the surfaces of the inner walls 8 and 9 so that the shapes of the surfaces of the inner walls 8 and 9 can be easily visually recognized.
Further, the image generation unit 242 also executes processing other than the emphasis processing and the color conversion processing as needed.

In this way, the image signal representing the image displayed on the display unit 12 is generated by performing the predetermined processing including the enhancement processing and the color conversion processing on the camera signal 11a.

The output unit 243 (see FIG. 16) of the control unit 24 sends the image signal to the display unit 12. The display unit 12 displays an image corresponding to this image signal, as shown in FIG. In the first embodiment, as described above, the field of view 11b of the camera 11 is wide, and the field of view 11b of the camera 11 includes not only the inside of the bore but also the outside of the bore. However, since the operator's concern is to bring the shoulder of the subject 10 into contact with the inner wall surface 82a, it is important for the operator to visually recognize the space inside the bore, and the outside of the bore. The image of does not need to be visually recognized. Therefore, in the first embodiment, the range displayed on the display unit 12 is limited so that the peripheral portion around the inner wall surface 82a can be visually recognized.

An image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized is displayed on the display unit 12, so that the operator can visually recognize the shapes of the surfaces of the inner walls 8 and 9.

When the operator is ready to move the subject 10 to the cradle 31, the operator operates the operation panel 13 (see FIG. 2) of the magnet 2 to move the cradle 31.

The operator refers to the image displayed on the display unit 12 and moves the cradle 31 so that the shoulder of the subject 10 contacts the inner wall surface 82a. Hereinafter, a method for the operator to move the cradle 31 will be described with reference to FIGS.

FIG. 19 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz1.
The image generation unit 242 continues to detect the shoulder portion based on the camera signal 11a even while the cradle 31 is moving. Therefore, even if the shoulder portion moves due to the movement of the cradle 31, the shoulder portion can be detected in real time.

In FIG. 19, the receiving coil 35 is displayed in the image on the display unit 12. Therefore, the operator can visually recognize from the image displayed on the display unit 12 that the shoulder is gradually approaching the inner wall surface 82a.

FIG. 20 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz2.
In FIG. 20, the display unit 12 displays an image including the receiving coil 35 and the head and shoulders of the subject 10.

The operator can visually recognize that the shoulder of the subject 10 is approaching the inner wall surface 82a by looking at the image displayed on the display unit 12. Therefore, the operator operates the operation panel 13 so as to reduce the moving speed of the cradle 31 while checking the image displayed on the display unit 12. Therefore, the cradle 31 continues to move at a low speed.

FIG. 21 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz3.
In FIG. 21, the shoulder of the subject 10 is closer to the inner wall surface 82a of the bore. Therefore, the operator repeats the operation of slightly moving the cradle 31, stopping the cradle 31 once, and starting the movement of the cradle 31 again. Therefore, the shoulder portion of the subject 10 gradually approaches the inner wall surface 82a of the bore.

FIG. 22 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz4.
In FIG. 22, the shoulder of the subject 10 is in contact with the inner wall surface 82a of the bore. Therefore, the operator operates the operation panel 13 (see FIG. 2) to stop the cradle 31. After stopping the cradle 31, the operator determines whether the position of the cradle 31 needs to be finely adjusted. When the head of the subject 10 needs to be moved further into the bore 7 (for example, when the head of the subject 10 does not sufficiently enter the imaging region 7a), the cradle 31 further moves in the z direction. Thus, the position of the cradle 31 is finely adjusted. On the other hand, when it is necessary to return the head of the subject 10 to the inner wall surface 82a side a little more (for example, when the force of pressing the shoulder portion of the subject 10 by the inner wall surface 82a is too strong), the operator sets the cradle 31 to -z. The position of the cradle 31 is finely adjusted so as to move in the direction.

When a portion of the inner wall 8 or 9 displayed on the display unit 12 overlaps with the subject 10, the inner wall 8 or 9 is hidden by the subject 10 in the overlapping portion. Therefore, the image generation unit 242 detects the above-mentioned overlapping portion from the camera signal 11a, and does not perform image processing and color conversion processing for shape enhancement on the overlapping portion. Therefore, unnecessary shape enhancement is performed on the subject 10, and the shoulder portion of the subject 10 is prevented from being converted into a color different from the original color. An image in which the shoulders of 10 are easily visually recognized is displayed. Therefore, the operator can visually recognize the position of the shoulder of the subject 10 by looking at the image on the display unit 12 without feeling uncomfortable.

After positioning the cradle 31, the operator performs a scan for acquiring an MR image of the head of the subject 10. In this way, the imaging of the subject 10 is completed.

In the first mode, the display unit 12 displays an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized. Therefore, the operator can easily visually recognize the shapes of the surfaces of the inner walls 8 and 9 by looking at the display unit 12, so that the cradle 31 can be moved safely. In the first embodiment, the shapes of both the inner walls 8 and 9 are emphasized. However, it is also possible to emphasize only the shape of the surface of the inner wall 8 without emphasizing the shape of the surface of the inner wall 9.

In the first embodiment, the camera 11 uses not only the bores 6 and 7 but also the space outside the bore 6 included in the field of view 11b (see FIG. 13). However, if the camera 11 has an imaging field of view 11b that allows the positional relationship between the inner wall surface 82a and the shoulder of the subject to be visually confirmed on the display unit 12, the imaging field of view 11b is as shown in FIG. It is not limited to the range shown.

Moreover, in the first embodiment, the inner wall portion 82 is formed in a substantially tapered shape. However, the inner wall portion 82 is not limited to the tapered shape, and may have another shape different from the tapered shape (for example, a substantially flat shape).

In the first embodiment, the image generating unit 242 generates an image so that the colors of the inner walls 8 and 9 are complementary to the color of the shoulder of the subject 10. Therefore, even if the subject 10 wears clothes having a color similar to the inner walls 8 and 9, the operator can look at the image displayed on the display unit 12 to see the shoulder and the inner walls 8 and 9 of the subject 10. The difference between and can be easily visually recognized. The colors of the inner walls 8 and 9 may be displayed on the display unit 12 in the original colors of the inner walls 8 and 9 without being the complementary color of the shoulder of the subject 10. is there.

(2) Second Mode In the first mode, the operator manually moves the cradle 31, but in the second mode, an example in which the cradle 31 is automatically moved will be described.

Compared to the MRI apparatus of the first aspect, the MRI apparatus of the second aspect differs in the processing executed by the control unit 24, but has the same hardware configuration. Therefore, in the description of the second mode, the processing executed by the control unit 24 will be mainly described.

In the second mode, the control unit 24 is configured to execute the following operations (b1)-(b8).
(B1) Receiving the camera signal 11a (b2) Generating an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized based on the camera signal 11a (b3) Based on the camera signal 11a To determine whether or not the shoulder reaches the vicinity of the inner wall surface 82a. (b4) When it is determined that the shoulder of the subject 10 reaches the vicinity of the inner wall surface 82a, the speed of the cradle 31 is decreased. (B5) Based on the camera signal 11a, it is determined whether the shoulder of the subject 10 contacts the inner wall surface 82a. (b6) The shoulder of the subject 10 contacts the inner wall surface 82a. When it is determined that the shoulder portion of the subject 10 needs to be pressed against the inner wall surface 82a, it is necessary to determine whether or not the shoulder portion of the subject 10 needs to be pressed against the inner wall surface 82a. If determined, generate a control signal for moving the cradle 31 so that the shoulder of the subject 10 is pressed against the inner wall surface 82a. (b8) Output a control signal.

The MRI apparatus 1 has a non-transitory computer-readable recording medium in which one or more instructions for executing the above operations (b1)-(b8) are stored. The above operations (b1)-(b8) are executed by the processor of the control unit 24 executing the instructions. Therefore, the control unit 24 has, as functional blocks, a reception unit 341, an image generation unit 342, a determination unit 343, a control signal generation unit 344, and an output unit 345 as functional blocks. The receiving unit 341 receives the camera signal 11a. The image generator 242 generates an image signal representing an image in which the shapes of the surfaces of the inner walls 8 and 9 are emphasized. The determination unit 343 determines whether or not the shoulder of the subject 10 has reached the vicinity of the inner wall surface 82a based on the camera signal 11a, and the shoulder of the subject 10 contacts the inner wall surface 82a based on the camera signal 11a. If it is determined that the shoulder of the subject 10 has contacted the inner wall surface 82a, it is determined whether the shoulder of the subject 10 needs to be pressed against the inner wall surface 82a. The control signal generator 344 generates a control signal for the cradle 31. The output unit 345 outputs the generated image signal to the display unit 12, and outputs the generated control signal to the cradle 31.

The programs for executing the operations (b3), (b5), and (b6) are, for example, the following image data D1 to Dn and E1 to En learned by the computer of the control unit 24 or the data processing unit 25. Then, it can be created based on the learning result.

(1) Image data D1 to Dn from the state where the human shoulder is located outside the bore until the human shoulder contacts the inner wall surface 82a of the bore
Similar to the first embodiment, the image data D1 to Dn are a series of image data acquired by the camera 11 while the cradle 31 is moved from the home position z0 by Δz (see FIG. 18).

(2) Image data E1 to En in which human shoulders are pressed against the inner wall surface 82a
FIG. 24 is an explanatory diagram of the image data E1 to En. In FIG. 24, the position z in the z direction of the cradle 31 when the human shoulder is in contact with the inner wall surface 82a of the inner wall portion 82 is shown as z=z10. The image data E1 to En are a series of image data acquired by the camera 11 while the cradle 31 is moved from z10 to z20 by Δz2 and the cradle 31 is moved by Δz2. When the cradle 31 is moved by Δz2 from z10, the force F received by the human shoulder from the inner wall surface 82a changes while the cradle 31 moves by Δz2. On the left side of FIG. 24, for reference, the difference in the shoulder shape when the position z in the z direction of the cradle 31 is z=z10, the shoulder shape when z10<z<z20, and the shoulder shape when z=z20 is schematically shown. Has been done. Since the image data E1 to En are images acquired while the force F received by the human shoulder from the inner wall surface 82a is changing, the shape of the shoulder shown in the image data E1 to En is also continuous. Changes to. Therefore, the image data E1 to En represent image data acquired while the shape of the shoulder changes continuously.

In the second mode, a computer is made to learn the above image data E1 to En. For example, the computer may include the position of the receiving coil 35 with respect to the inner wall surface 82a, the position of the shoulder with respect to the receiving coil 35, the shape of the shoulder when the shoulder portion is not in contact with the inner wall surface 82a, and the shoulder portion with the inner wall surface 82a. The shape of the shoulder at that time, the shape of the shoulder when the shoulder is pushed into the inner wall surface 82a, the relative positional relationship between the imaging region 7a, the receiving coil 35, and the shoulder are learned. By this learning, a program (source code) for executing the above operations (b3), (b5), and (b6) can be created. The program created in this way is recorded in the storage medium of the control unit 24.

An example of a method of moving the subject 10 into the bore in the second mode will be described below.

First, as shown in FIG. 15, the operator lays the subject 10 on the cradle 31. When the operator is ready to move the subject 10 to the bore of the magnet 2, the operator operates the operation panel 13 (see FIG. 2) to input a signal for moving the subject 10 into the bore. When this signal is input, the cradle 31 automatically moves so that the head of the subject 10 is positioned within the bore. The operation of the MRI apparatus in the second mode from the start of the movement of the cradle 31 to the stop thereof will be described below.

FIG. 25 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz1.
The determination unit 343 (see FIG. 23) determines whether the shoulder of the subject 10 has reached the vicinity of the inner wall surface 82a based on the camera signal 11a. When the shoulder reaches the vicinity of the inner wall surface 82a, this means that the shoulder will soon contact the inner wall surface 82a. When the shoulder portion contacts the inner wall surface 82a, the shoulder portion receives a force from the inner wall surface 82a. Therefore, in order to reduce the force received by the shoulder portion from the inner wall surface 82a as much as possible, the shoulder portion contacts the inner wall surface 82a at the slowest speed. It is desirable to do. Therefore, in the second embodiment, when the shoulder reaches the vicinity of the inner wall surface 82a, the control signal generator 344 generates a control signal for reducing the speed of the cradle 31.

As a method of determining whether or not the shoulder has reached the vicinity of the inner wall surface 82a, for example, data representing the reference plane Sr for defining the vicinity of the inner wall surface 82a is registered in the database of the control unit 24. A method of determining that the shoulder has reached the vicinity of the inner wall surface 82a when the shoulder contacts or intersects the reference plane Sr is conceivable. When it is determined that the shoulder has reached the vicinity of the inner wall surface 82a, the control signal generation unit 344 generates a control signal that reduces the speed of the cradle 31. On the other hand, when it is determined that the shoulder has not reached the vicinity of the inner wall surface 82a, the control signal for reducing the speed of the cradle 31 is not generated, so the cradle 31 continues to move at the same speed. In FIG. 25, the shoulder has not yet reached the reference plane Sr. Therefore, the control unit 24 moves the cradle 31 without reducing the speed of the cradle 31.

FIG. 26 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz2.
The determination unit 343 determines whether the shoulder of the subject 10 has reached the vicinity of the inner wall surface 82a based on the camera signal 11a. In FIG. 26, since the shoulder portion is in contact with the reference surface Sr, the determination unit 343 determines that the shoulder portion of the subject 10 has reached the vicinity of the inner wall surface 82a. Therefore, the control signal generation unit 344 generates the control signal for reducing the speed of the cradle 31. The output unit 345 (see FIG. 23) outputs this control signal to the cradle 31. The cradle 31 moves at a low speed in response to this control signal.

FIG. 27 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz4.
The determination unit 343 determines whether or not the shoulder of the subject 10 contacts the inner wall surface 82a based on the camera signal 11a. In FIG. 27, the shoulder is in contact with the inner wall surface 82a. Therefore, the determination unit 343 determines that the shoulder is in contact with the inner wall surface 82a.

When it is determined that the shoulder has contacted the inner wall surface 82a, the determination unit 343 determines whether the shoulder of the subject 10 needs to be pressed against the inner wall surface 82a. The determination unit 343, for example, the head of the subject 10 sufficiently enters the imaging region 7a based on the relative positional relationship between the imaging region 7a, the receiving coil 35, and the shoulder, the shape of the shoulder, and the like. Is determined. When it is determined that the head of the subject 10 does not sufficiently enter the imaging region 7a, the head of the subject 10 enters the imaging region 7a (or is positioned as close as possible to the imaging region 7a). Therefore, it is determined that the shoulder of the subject 10 needs to be pressed against the inner wall surface 82a. In this case, the control signal generation unit 344 generates a control signal for controlling the movement of the cradle 31 so that the cradle 31 moves from z=z4 in the z direction by Δzd (see FIG. 28).

FIG. 28 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 is moved by Δzd from z4.
In FIG. 28, the determination unit 343 determines that the inner wall surface 82a cannot force the shoulder of the subject 10 based on the relative positional relationship between the imaging region 7a, the receiving coil 35, and the shoulder, the shape of the shoulder, and the like. Determine if force is being applied. When the shoulder of the subject 10 receives too much force from the inner wall surface 82a, from the viewpoint of reducing the physical burden on the subject 10, the shoulder of the subject 10 receives less force from the inner wall surface 82a. It is desirable to finely adjust the position of the cradle 31. Therefore, the determination unit 343 determines whether an unreasonable force is applied to the shoulder of the subject 10 based on the shape of the shoulder of the subject 10 and the like. When it is determined that an unreasonable force is applied to the shoulder of the subject 10, the control signal generation unit 344 moves the position of the cradle 31 in the direction opposite to the z direction (−z direction) by a predetermined distance Δzd′. Generate a control signal for returning. In response to this control signal, the cradle 31 returns by Δzd′ in the direction opposite to the z direction, so that the physical load on the subject 10 can be reduced.

On the other hand, when it is determined that an unreasonable force is not applied to the shoulder of the subject, the determination unit 343 determines the relative positional relationship between the imaging region 7a, the receiving coil 35, and the shoulder, the shape of the shoulder, and the like. Based on the above, it is also determined whether or not the head of the subject 10 fully enters the imaging region 7a (or is positioned at a position sufficiently close to the imaging region 7a). When it is determined that the head of the subject 10 has sufficiently entered the imaging region 7a (or the head of the subject 10 is positioned sufficiently close to the imaging region 7a), the operator is asked to -Notification that the movement of the dollar 31 is completed. The MRI apparatus 1 visually notifies that the movement of the cradle 31 has been completed (for example, displays an image indicating that the movement of the cradle 31 has been completed) on the display unit 12 or aurally. (For example, the speaker outputs a sound indicating that the movement of the cradle 31 is completed).

On the other hand, when it is determined that the head of the subject 10 does not sufficiently enter the imaging region 7a (or the head of the subject 10 is not positioned sufficiently close to the imaging region 7a), The control signal generation unit 344 generates a control signal for moving the cradle 31 in the z direction so that the head of the subject 10 is fed into the bore 7. The control signal generation unit 344 generates, for example, a control signal for moving the cradle 31 from the position z4+Δzd by Δzd. The output unit 345 outputs this control signal to the cradle 31. The cradle 31 moves the cradle 31 in response to the control signal until the cradle 31 reaches the position of z4+2·Δzd. After the cradle 31 is moved, the determination unit 343 again determines whether the shoulder of the subject 10 is unreasonably forceed, and further, the head of the subject 10 sufficiently enters the imaging region 7a. It is also determined whether or not it is positioned (or positioned sufficiently close to the imaging area 7a), and the position of the cradle 31 is adjusted if necessary.

In this way, when the position of the cradle 31 is adjusted and the position of the cradle 31 is determined, the operator is notified that the movement of the cradle 31 has been completed.

When the movement of the cradle 31 is completed, a scan for acquiring an MR image of the head of the subject 10 is performed. In this way, the imaging of the subject 10 is completed.

In the second mode, the cradle 31 is automatically positioned. Therefore, the work load on the operator can be reduced.

In the second embodiment, when the shoulder reaches the vicinity of the inner wall surface 82a, the speed of the cradle 31 is reduced. Therefore, the shoulder portion of the subject 10 can be brought into contact with the inner wall surface 82a without applying an unreasonable force to the shoulder portion of the subject 10.

Further, in the second embodiment, after moving the cradle 31 so that the shoulder of the subject 10 contacts the inner wall surface 82a, the head of the subject 10 does not sufficiently enter the imaging region 7a (or, If the head of the subject 10 is not positioned sufficiently close to the imaging area 7a), the cradle 31 can be moved so that the head of the subject 10 is fed into the bore 7. Therefore, even if the head of the subject 10 cannot be positioned in the imaging region 7a in which the static magnetic field is highly uniform simply by bringing the shoulder portion of the subject 10 into contact with the inner wall surface 82a, The head can be brought close to the imaging region 7a.

In the second embodiment, when the shoulder portion of the subject 10 is pressed against the inner wall surface 82a and an unreasonable force is applied to the shoulder portion of the subject 10 from the inner wall surface 82a, the shoulder portion of the subject 10 is The position of the cradle 31 is finely adjusted so that the force received from the inner wall surface 82a becomes small. Therefore, the physical burden on the subject 10 can be sufficiently reduced.

In the second embodiment, the shape of the surface of the inner wall is emphasized in the image displayed on the display unit 12, and the color of the inner wall is converted into a color complementary to the color of the shoulder of the subject. .. However, in the second embodiment, since the movement of the cradle 31 is automatically controlled, the display unit 12 may display an image for which shape enhancement processing or color conversion processing has not been executed.

(3) Third Mode In the MRI apparatus 1, the bore 7 into which the head is received is narrow. Therefore, if the subject 10 puts his/her hand on the receiving coil 35 for some reason, the hand of the subject 10 may get into the gap between the receiving coil 35 and the inner wall 9 of the bore 7. .. Therefore, when the cradle 31 is automatically moved, it is desirable to automatically determine whether or not the receiving coil 35 is touched from the viewpoint of enhancing the safety of the subject 10. Therefore, in the third embodiment, an example having a function of automatically determining whether or not the receiving coil 35 is untouched will be described.

The MRI apparatus of the third mode is different from the MRI apparatus of the first mode in the processing executed by the control unit 24, but the hardware configuration is the same. Therefore, in the description of the third mode, the processing executed by the control unit 24 will be mainly described.

In the third mode, the control unit 24 is configured to execute the following operation in addition to the operations (b1)-(b8) described in the second mode.
(C1) Determining whether the hand of the subject 10 is attached to the receiving coil 35 based on the camera signal 11a. (c2) It is determined that the hand of the subject 10 is attached to the receiving coil 35. Generate a control signal that controls the movement of the cradle 31 so that the cradle 31 stops.

The MRI apparatus 1 has a non-transitory computer-readable recording medium in which, in addition to (b1)-(b8), one or more instructions for executing (c1) and (c2) are stored. ing. When the processor of the control unit 24 executes the instructions, the operations (b1)-(b8) and (c1) and (c2) described above are executed. The processor of the control unit 24 reads the program in which the above instruction is described from the recording medium and executes the instruction. The determination unit 323 (see FIG. 23) makes the determination of (c1), and the control signal generation unit 344 (see FIG. 23) generates the control signal of (c2).

The program for executing the operation (c1) can be created based on the learning result by learning the following image data F1 to Fn by the computer of the control unit 24 or the data processing unit 25, for example. ..

(1) Image data F1 to Fn in which a person touches the receiving coil 35
FIG. 29 is an explanatory diagram of the image data F1 to Fn. FIG. 29 shows that the cradle 31 is located at the home position z0. The image data F1 to Fn are acquired by the camera 11 while the cradle 31 is moved from the home position z0 by a distance Δz while a person holds the receiving coil 35 and the cradle 31 is moved by Δz. It is a series of image data. Therefore, a series of image data F1 to Fn can be acquired for one person. Further, the operation of acquiring the image data F1 to Fn is repeated with the receiving coil 35 being put on a hand by changing the person who sleeps in the cradle 31 to another person. As a result, image data can be acquired for various people while the cradle 31 is moving.

In the third mode, a computer is made to learn the above image data F1 to Fn. The computer learns, for example, the position of the hand with respect to the receiving coil 35, the shape of the hand, and the like. By this learning, a program (source code) for executing the above operation (c1) can be created. The program created in this way is recorded in the storage medium of the control unit 24.

Hereinafter, an example of a method of moving the subject 10 into the bore in the third embodiment will be described.

First, as shown in FIG. 15, the operator lays the subject 10 on the cradle 31. When the operator is ready to carry the subject 10 to the bore of the magnet 2, the operator operates the operation panel 13 (see FIG. 2) to input a signal for moving the subject 10 into the bore. When this signal is input, the cradle 31 automatically moves so that the head of the subject 10 is positioned in the bore. When the hand of the subject 10 is not attached to the receiving coil 35, the cradle 31 automatically moves as described in the second mode.

On the other hand, when the subject 10 touches the receiving coil 35 while the cradle 31 is moving, the MRI apparatus 1 operates as follows (see FIG. 30).

FIG. 30 is an explanatory diagram of the MRI apparatus in a state where the cradle 31 has moved by Δz2.
The determination unit 343 determines whether the hand of the subject 10 is attached to the reception coil 35. In FIG. 30, the hand of the subject 10 is attached to the receiving coil 35. Therefore, the determination unit 343 determines that the hand of the subject 10 is attached to the receiving coil 35. In this case, the control signal generator 344 generates a control signal for controlling the movement of the cradle 31 so that the cradle 31 stops. The output unit 345 outputs a control signal for stopping the cradle 31. Therefore, the cradle 31 stops in response to this control signal.

In the third embodiment, when the subject 10 touches the receiving coil 35 while the cradle 31 is moving, the cradle 31 automatically stops. Therefore, it is possible to prevent the hand of the subject 10 from entering the gap between the receiving coil 35 and the inner wall 9 in advance, so that the subject 10 can be moved safely.

1 MRI apparatus 2 Magnet 3 Table 5 Enclosure 6, 7 Bore 8, 9 Inner wall 10 Subject 11 Camera 12 Display 13 Operation panel 15 Gradient coil 16 RF coil 20 T/R switch 21 RF driver unit 22 Gradient coil driver unit 23 Data Collection unit 24 Control unit 25 Data processing unit 26 Operation console unit 27 Display unit 31 Cradle 35 Receiving coil 35a Receiving parts 81, 82 Inner wall part 82a Inner wall surface

Claims (8)

A cradle that supports the subject,
A first inner wall defining a first bore for receiving the chest and shoulders of the subject, the first inner wall having an inner wall surface with which the shoulder contacts, and a first inner wall for receiving the head of the subject A magnet having a second inner wall defining two bores;
Image acquisition means for acquiring an image in the first bore using an optical lens and outputting a signal representative of the image;
Image generation means for generating an image in which the shape of the surface of the first inner wall is visually enhanced based on the signal obtained from the image acquisition means;
A magnetic resonance imaging apparatus comprising: a display unit that displays the image. A cradle that supports the subject,
A first inner wall defining a first bore for receiving the chest and shoulders of the subject, the first inner wall having an inner wall surface with which the shoulder contacts, and a first inner wall for receiving the head of the subject A magnet having a second inner wall defining two bores;
Image acquisition means for acquiring an image in the first bore using an optical lens and outputting a signal representative of the image;
And a control means for controlling the movement of the cradle,
The control means is
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder of the subject has reached the vicinity of the inner wall surface, and the shoulder of the subject has reached the vicinity of the inner wall surface. In the case of outputting a control signal for reducing the speed of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject contacts the inner wall surface, and when the shoulder portion of the subject contacts the inner wall surface, Determining whether or not it is necessary to press the shoulder portion of the sample against the inner wall surface,
When it is determined that the shoulder portion of the subject needs to be pressed against the inner wall surface, a control signal for moving the cradle is output so that the shoulder portion of the subject is pressed against the inner wall surface. A magnetic resonance imaging apparatus for performing. It is equipped with a coil attached to the head of the subject,
The control means is
Based on the signal obtained from the image acquisition means, it is determined whether the hand of the subject is attached to the coil, and when the hand is attached to the coil, the cradle is stopped. The magnetic resonance imaging apparatus according to claim 2, wherein the magnetic resonance imaging apparatus generates a control signal for controlling the movement of the cradle. The magnetic resonance imaging according to claim 2 or 3, further comprising image generation means for generating an image in which the shape of the surface of the first inner wall is visually enhanced based on the signal obtained from the image acquisition means. apparatus. The image in which the shape of the surface of the first inner wall is visually emphasized is an image in which shading or shading is given according to the shape of the surface of the first inner wall, according to claim 1 or 3. Magnetic resonance imaging system. The image generation means,
The method of identifying a complementary color of the color of the shoulder of the subject, and converting the color of the first inner wall into a complementary color of the color of the shoulder of the subject are performed. The magnetic resonance imaging apparatus described. A first inner wall defining a first bore for receiving a chest and a shoulder of the subject, the first inner wall having an inner wall with which the shoulder contacts, and a second inner wall for receiving the head of the subject An image acquisition means for acquiring an image in the first bore by using a magnet having a second inner wall defining a bore of the image, and an optical lens, and outputting a signal representing the image; Is a program applied to a magnetic resonance imaging apparatus having a display means for displaying,
An image generation process for generating an image in which the shape of the surface of the first inner wall is visually emphasized based on the signal obtained from the image acquisition means,
A program that causes a computer to execute. A cradle for supporting a subject, a first inner wall defining a first bore for receiving the chest and shoulders of the subject, the first inner wall having an inner wall surface with which the shoulder contacts; A magnet having a second inner wall defining a second bore for receiving the head of the subject and an image in the first bore are acquired using an optical lens and a signal representative of the image is output. An image acquisition means for, and a program applied to a magnetic resonance imaging apparatus having a control means for controlling the movement of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder of the subject has reached the vicinity of the inner wall surface, and the shoulder of the subject has reached the vicinity of the inner wall surface. In the case, a process of outputting a control signal for reducing the speed of the cradle,
Based on the signal obtained from the image acquisition means, it is determined whether or not the shoulder portion of the subject contacts the inner wall surface, and when the shoulder portion of the subject contacts the inner wall surface, Processing to determine whether or not the shoulder portion of the sample needs to be pressed against the inner wall surface, and, if it is determined that the shoulder portion of the subject needs to be pressed against the inner wall surface, the shoulder portion of the subject is A program for causing a computer to execute a process of outputting a control signal for moving the cradle so that the computer is pressed against the inner wall surface.