JP5660814B2 - Magnetic resonance imaging system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus that collects magnetic resonance signals from a subject.

When imaging a subject with a magnetic resonance imaging apparatus, the subject is transported into the bore. However, since the bore is a narrow space, when the subject is claustrophobic, the subject may not be able to withstand imaging and may not be able to continue imaging. In addition, when an operator gives a necessary instruction to a subject during imaging, the instruction is generally transmitted by voice, but when the subject is a hearing impaired person, a voice instruction cannot be given. As a method of solving the above problems, a liquid crystal display (LCD) in the bore is used.
A method of installing a Crystal Display) is known (for example, see Patent Document 1).

JP 2003-190112 A

  In the method of Patent Document 1, when the subject is claustrophobia, an image that gives a sense of security to the subject is displayed on the LCD. Further, when the subject is a hearing impaired person, necessary instructions are displayed on the LCD. However, since a strong magnetic field is generated around and around the bore of the magnetic resonance imaging apparatus, the LCD cannot operate normally under the influence of the generated strong magnetic field. There is a problem that it is difficult to display necessary information (for example, video, instructions). Therefore, it is desired to display necessary information on the subject without being influenced by the strong magnetic field of the magnetic resonance imaging apparatus.

The invention for solving the problem is a magnetic resonance imaging apparatus for collecting magnetic resonance signals from a subject,
A magnetic field generator;
Electronic paper that is provided in the magnetic field generator and displays predetermined information;
Is a magnetic resonance imaging apparatus.

  By using electronic paper, information can be displayed on the subject.

1 is a schematic diagram of a magnetic resonance imaging apparatus according to a first embodiment. It is explanatory drawing of the electronic paper. It is a figure which shows the magnetic field generator 2 and the tables 3 and 4 which are arrange | positioned in the shield room 101, and the control apparatus 7 arrange | positioned outside the shield room 101. FIG. 6 is a diagram illustrating an example of information displayed on the electronic paper 5. FIG. It is explanatory drawing of an experimental result. It is the schematic of the MRI apparatus 200 of 2nd Embodiment. It is a side view of the magnetic field generator 2 and the tables 3 and 4 arrange | positioned in the shield room 101. FIG. 6 is a diagram illustrating an example of information displayed on the electronic paper 5. FIG. It is explanatory drawing of the cable 6 in the MRI apparatus of 3rd Embodiment. It is a figure which shows an example of the cable which has a ferrite. It is a figure which shows another example of the cable which has a ferrite. It is a figure which shows another example of the cable which has a ferrite.

  Hereinafter, although the form for inventing is demonstrated, this invention is not limited to the following forms.

(1) First Embodiment FIG. 1 is a schematic diagram of a magnetic resonance imaging apparatus according to a first embodiment.

  A magnetic resonance imaging (MRI) apparatus 100 includes a magnetic field generator 2, tables 3 and 4, etc. in a shield room 101.

  The magnetic field generator 2 has a tunnel-type accommodation space 21 in which the subject 11 is accommodated. A table 3 is disposed on the front side of the magnetic field generator 2, and a table 4 is disposed on the rear side of the magnetic field generator 2. The table 3 has a cradle 31 on which the subject 11 is placed. As the cradle 31 moves in the z direction, the subject 11 is carried into the accommodation space 21.

  In addition, on the inner wall 22 of the accommodation space 21 of the magnetic field generation device 2, predetermined information (for example, the remaining time of scanning, precautions at the time of imaging, and an image that matches the preference of the subject 11) is displayed on the subject 11. Electronic paper 5 is attached. The electronic paper 5 will be described in detail later.

The MRI apparatus 100 includes a control device 7 that controls the electronic paper 5, a console 8, and the like outside the shield room 101. The electronic paper 5 and the control device 7 are connected by a cable 6. The operator 12 can input information necessary for photographing by operating the console 8.
Next, the electronic paper 5 will be described with reference to FIG.

FIG. 2 is an explanatory diagram of the electronic paper 5.
FIG. 2A is a perspective view showing the magnetic field generator 2. FIG. 2B is an exploded view of the inner wall 22 of the accommodating space 21 at the position of the line P1 in FIG. FIG.

  The inner wall 22 of the storage space 21 includes a support surface 22a (indicated by hatching in FIG. 2B) for supporting the cradle 31 carried into the storage space 21, and a curved surface 22b connected to the support surface 22a. have.

  The electronic paper 5 is attached so as to cover almost the entire surface of the curved surface 22 b of the inner wall 22. Since the thickness of the electronic paper 5 is as thin as paper and can be bent, it can be easily attached to the curved surface 22b of the inner wall 22.

  FIG. 3 is a diagram showing the magnetic field generator 2 and the tables 3 and 4 arranged in the shield room 101 and the control device 7 arranged outside the shield room 101.

  In addition, about the magnetic field generator 2, the cross section in yz surface is shown in order to make the position of the electronic paper 5 easy to understand.

  The magnetic field generator 2 includes a superconducting coil 23, a gradient coil 24, and a transmission coil 25. The superconducting coil 23 applies a static magnetic field, the gradient coil 24 applies a gradient magnetic field, and the transmission coil 25 transmits an RF pulse. In place of the superconducting coil 23, a permanent magnet may be used.

  The electronic paper 5 attached to the inner wall of the accommodation space 21 is connected to the control device 7 arranged outside the shield room 101 by a cable 6. The electronic paper 5 receives a signal from the control device 7 through the cable 6 and responds to the signal received from the control device 7 with predetermined information (for example, remaining time of scanning, precautions at the time of photographing, The image according to the taste of the specimen 11 is displayed. Since the electronic paper 5 is attached to the inner wall 22 of the accommodation space 21, the subject 11 can easily visually recognize the information displayed on the electronic paper 5 in the accommodation space 21. Hereinafter, an example of information displayed on the electronic paper 5 will be described.

  FIG. 4 is a diagram illustrating an example of information displayed on the electronic paper 5. FIG. 4 shows a state when the electronic paper 5 is viewed from the front side of the accommodation space 21.

  In FIG. 4A, the electronic paper 5 displays a flower field and a blue sky, and further displays a remaining scan time T in the blue sky. In FIG. 4B, the electronic paper 5 displays a forest, and further displays the remaining scan time T in the forest. 4A and 4B show an example in which the remaining scan time T is T = 2 minutes 45 seconds.

  As shown in FIG. 4, the anxiety felt by the subject 11 can be reduced even when the subject is claustrophobia by displaying a flower field or a forest. Since the remaining scan time T is displayed, the remaining scan time T can be visually recognized even if the subject 11 is a hearing impaired person. The information displayed on the electronic paper 5 is not limited to the information shown in FIG. For example, when performing a breath holding scan, the timing of the breath holding, the remaining time until the breath holding scan ends, and the like may be displayed.

  Also, since the electronic paper 5 requires a very small amount of power when rewriting information compared to a liquid crystal display, almost no noise is generated. Therefore, even if information is rewritten during scanning of the subject 11, a high quality MR image can be obtained.

  As the electronic paper 5, it is preferable to use an electrophoretic electronic paper. Electrophoretic electronic paper is hardly affected by a magnetic field even when used in a strong magnetic field, so that necessary information can be displayed correctly. In order to verify that electrophoretic electronic paper can correctly display necessary information even in a strong magnetic field, an experiment was conducted using electrophoretic electronic paper. The experimental results will be described below.

FIG. 5 is an explanatory diagram of the experimental results.
In the experiment, an electrophoretic electronic paper 50 was attached to the inner wall 22 of the accommodation space 21 of the MRI apparatus, and the numeral “7” was displayed on the electronic paper 50. Referring to FIG. 5, the number “7” is clearly displayed on the electronic paper 50, and it can be seen that the electrophoretic electronic paper can correctly display necessary information even in a strong magnetic field. In addition, if it is not substantially affected by a magnetic field, another type of electronic paper may be used. However, it is desirable not to use electronic paper using a device such as a magnetic twist ball or a magnetic thermosensitive type because it is highly likely that the electronic paper does not operate normally due to the influence of the magnetic field of the magnetic field generator 2.

  In the first embodiment, the case where the accommodation space 21 for accommodating the subject is a tunnel type is described. However, the present invention can be applied even when the accommodation space is an open type.

(2) Second Embodiment In the first embodiment, the MRI apparatus 100 in which the electronic paper 5 is attached to the inner wall 22 of the accommodation space 21 is described. In the second embodiment, the electronic paper is a magnetic field. The MRI apparatus attached to the outer surface of the generator will be described.

FIG. 6 is a schematic view of the MRI apparatus 200 of the second embodiment, and FIG. 7 is a side view of the magnetic field generator 2 and the tables 3 and 4 arranged in the shield room 101.
It is.

  In the MRI apparatus 200 of the second embodiment, the electronic paper 5 is attached to the outer surface of the magnetic field generator 2, but the other configurations are the same as those of the MRI apparatus 100 of the first embodiment.

FIG. 8 is a diagram illustrating an example of information displayed on the electronic paper 5.
In the second embodiment, the electronic paper 5 displays personal information (for example, name, date of birth, weight) of the subject 11. By displaying the personal information of the subject 11, when the subject 11 enters the shield room 101, the subject 11 can confirm the identity of himself / herself, thereby preventing the examination subject from being mistaken. be able to. Further, by attaching the electronic paper 5 to the outer surface of the magnetic field generator 2, the operator 12 can easily confirm the personal information of the subject 11 displayed on the electronic paper 5. Among the personal information of the subject 11, the weight of the subject 11 is very important information from the viewpoint of SAR (Specific Absorption rate) and the like, so that the operator 12 can easily confirm the weight of the subject 11. It is also preferable from the aspect of safety management. Furthermore, for example, when the subject 11 is a small child, an image (an anime character or the like) that suits the taste of the subject 11 may be displayed on the electronic paper 5. When the subject 11 is a small child, anxiety of the child can be reduced by causing the electronic paper 5 to display an image that suits the taste of the subject 11.

(3) Third Embodiment As shown in FIG. 3, the cable 6 is disposed near the transmission coil 25. Therefore, the RF pulse transmitted from the transmission coil 25 may become high frequency noise and reach the control device 7 via the cable 6. When the high frequency noise reaches the control device 7, the control device 7 may break down. Therefore, it is desirable that the control device 7 be protected from the high frequency noise. Therefore, in the MRI apparatus of the third embodiment, the cable 6 is configured so that the control device 7 can be protected from high-frequency noise. Below, the cable 6 in the MRI apparatus of 3rd Embodiment is demonstrated. The MRI apparatus of the third embodiment is the same as the MRI apparatus 100 of the first embodiment except for the cable. Therefore, in describing the third embodiment, the cable will be mainly described.

FIG. 9 is an explanatory diagram of the cable 6 in the MRI apparatus of the third embodiment.
The cable 6 includes n signal lines S1 to Sn, an inner shield 61, an outer shield 62, an insulator 63, and a capacitor C.

  The inner shield 61 is provided so as to cover the signal lines S <b> 1 to Sn from the position of the electronic paper 5 to a position near the control device 7. The outer shield 62 is shorter than the inner shield 61 and is provided on the electronic paper 5 side. An insulator 63 is provided between the inner shield 61 and the outer shield 62. The capacitor C is provided between the inner shield 61 and the signal lines S1 to Sn.

  The cable 6 of the third embodiment has not only a single shield structure by the inner shield 61 but also a double shield structure by the inner shield 61 and the outer shield 62. Therefore, most of the high-frequency noise due to the RF pulse is shielded and prevented from entering the signal lines S1 to Sn. Note that the lengths of the inner shield 61 and the outer shield 62 are not limited to the lengths shown in FIG. 9, and may be changed as appropriate. For example, the length of the outer shield 62 may be the same as that of the inner shield 61.

  Further, since the cable 6 has the capacitor C, even if high frequency noise is mixed in the signal lines S1 to Sn, most of the high frequency noise mixed in the signal lines S1 to Sn can be removed by the capacitor C. . For this reason, even if high frequency noise is mixed in the signal lines S1 to Sn, most of the high frequency noise mixed in the signal lines S1 to Sn can be removed before reaching the control device 7, and the control device 7 It is possible to prevent failure due to high frequency noise.

Further, the cable 6 may include ferrite (see FIG. 10).
FIG. 10 is a diagram illustrating an example of a cable having ferrite.

  The cable 6 shown in FIG. 10 includes ferrite F in addition to the n signal lines S1 to Sn, the inner shield 61, the outer shield 62, the insulator 63, and the capacitor C. Ferrite F is attached to the inner shield 61. By providing the ferrite F, it is possible to further remove high-frequency noise mixed in the signal lines S1 to Sn.

  In FIG. 10, the ferrite F is attached to the inner shield 61, but it may be attached to the signal lines S1 to Sn (see FIG. 11), or to both the inner shield 61 and the signal lines S1 to Sn. You may attach (refer FIG. 12).

  In the third embodiment, a capacitor C (see FIG. 9) or a capacitor C and a ferrite F (FIGS. 10 to 12) is shown as a noise removal filter for removing noise mixed in the signal lines S1 to Sn. ing. However, a component (for example, a balun) other than the capacitor C and the ferrite F may be used as a noise removal filter.

2 Magnetic field generator 3, 4 Table 5 Electronic paper 6 Cable 7 Control device 8 Console 11 Subject 21 Housing space 22 Inner wall 22a Support surface 22b Curved surface 23 Superconducting coil 24 Gradient coil 25 Transmitting coil 31 Cradle 100, 200 MRI apparatus 101 Shield The room

Claims (9)

A magnetic resonance imaging apparatus for collecting magnetic resonance signals from a subject,
A magnetic field generator installed in a shield room;
Electronic paper that is provided in the magnetic field generator and displays predetermined information;
A control device installed outside the shield room and controlling the electronic paper;
A cable connecting the electronic paper and the control device;
The cable has a signal line, an inner shield that covers the signal line, and an outer shield that is located outside the inner shield, and the inner shield and the outer shield form a double shield structure,
The inner shield and the outer shield extend from the electronic paper, and the outer shield is shorter than the inner shield. The magnetic field generator has a storage space in which the subject is stored,
The magnetic resonance imaging apparatus according to claim 1, wherein the electronic paper is attached to an inner wall of the accommodation space.   The magnetic resonance imaging apparatus according to claim 1, wherein the electronic paper is attached to an outer surface of the magnetic field generator.   The magnetic resonance imaging apparatus according to claim 1, wherein the cable includes an insulator between the inner shield and the outer shield.   The magnetic resonance imaging apparatus according to claim 1, wherein the cable includes a noise removal filter that removes noise mixed in the signal line.   The magnetic resonance imaging apparatus according to claim 5, wherein the noise removal filter is a capacitor, a ferrite, or a balun.   The magnetic resonance imaging apparatus according to claim 6, wherein the noise removal filter is a ferrite, and the ferrite is attached to the signal line or the inner shield.   The magnetic resonance imaging apparatus according to claim 1, wherein the electronic paper is an electrophoretic type.   9. The control device according to claim 1, wherein the electronic paper causes the electronic paper to display a remaining scan time, a precaution during photographing, an image that suits a subject's preference, or personal information of the subject. Magnetic resonance imaging equipment.