JP4208354B2 - Head mat - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a head mat laid under the head of a subject at the time of imaging by a magnetic resonance imaging apparatus. The present invention relates to a head mat that can be suppressed.
[0002]
[Prior art]
In general, when imaging with a medical modality such as a magnetic resonance imaging apparatus while the subject is laid on a bed, a pillow, that is, a head mat is often placed under the head of the subject. This is especially necessary when diagnosing the head. By laying the mat, the patient can take a comfortable sleeping posture by the pillow function, and can also suppress the movement of the head.
[0003]
Conventionally, the head mat having the structure shown in FIGS. 6 and 7 is used as the head mat that also functions as a pillow function and a movement suppressing function. These mats are all arranged on the inner peripheral surface side of the QD coil unit (RF coil) of the magnetic resonance imaging apparatus.
[0004]
The former head mat 101 has a structure in which a plate-like member such as a flexible sponge is curved. The degree of this curvature is formed in accordance with the size of the occipital region of the majority of people. In addition to the former structure, the latter head mat 102 is provided with a recessed portion 102a having a shape extending from the back of the subject to the neck.
[0005]
[Problems to be solved by the invention]
However, in the head mat having the structure shown in FIGS. 6 and 7, the following inconveniences still remain.
[0006]
That is, in the former head mat 101, since the degree of curvature of the mat body is adjusted to the average value of the occipital dimension so that it can be used in common for many patients, it is for so-called everyone. However, because the size of the head varies from patient to patient, a situation arises where the head moves easily. If the head moves during MR scanning, the resolution of the captured image may be degraded, or artifacts may be generated, resulting in unnecessarily reduced diagnostic performance. become.
[0007]
On the other hand, in the latter head mat 102, the pillow function and the movement suppression are good for the patient at the back of the head that fits the size of the recess 102a. However, for a patient with a occipital region larger or smaller than the depression 102a, the function of the depression 102a is hardly exhibited, and only a sense of incongruity is given. That is, the head mat 102 is not intended for everyone, and there is a problem that the target patients are limited.
[0008]
Therefore, it is conceivable to prepare in advance various types of head mats having different sizes of the depressions 102a. However, this increases the cost, and the mats are replaced for each patient so that QD coils (RF coils) can be used. Since the setting operation increases, the operational burden on the operator increases.
[0009]
Furthermore, the above-described conventional head mats 101 and 102 have a structure in which it is not borne in mind that the sensitivity region of the RF coil is shown. For this reason, positioning of the patient's head and the RF coil has to rely on other means and experience, so positioning may be cumbersome or inaccurate.
[0010]
The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and refers to a large number of subjects (here, a large number of patients having various head sizes as well as a specific head size). It is an object of the present invention to provide a head mat for medical imaging using a magnetic resonance imaging apparatus , which can function as a pillow and suppress inadvertent movement of the head.
[0011]
Further, the present invention is based on a magnetic resonance imaging apparatus that fits a large number of subjects, functions as a pillow, can suppress inadvertent movement of the head, and does not impose an operational burden on the operator. Another object is to provide a head mat for medical imaging.
[0012]
Furthermore, the present invention fits many subjects, functions as a pillow, suppresses inadvertent movement of the head, and easily and more accurately positions the patient's head and the RF coil. It is another object to provide a head mat that can be used for medical imaging with a magnetic resonance imaging apparatus .
[0013]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, a head for use have laid under the head of the subject at the time of imaging by magnetic resonance imaging apparatus with a head RF coil of the magnetic resonance imaging apparatus in mats, and mats body formed of a member flexible, the people left respectively of the mat end is positioned on the head neck side on the mat body, and the formed bulge in member having flexibility, said mat A cover that covers the main body and the bulge portion and that is provided with a marker that represents a sensitivity region of the RF coil for the head is provided .
[0014]
Thereby, it fits on many subjects, functions as a pillow, and can suppress inadvertent movement of the head. Therefore, each time the patient (subject) changes, it is possible to eliminate or greatly reduce the operator's trouble of replacing the head mat and adjusting the fit. In addition, artifacts due to the movement of the medical imaging image can be reduced, and the image quality is improved. Furthermore, positioning of the patient's head and the RF coil can be performed easily and more accurately.
[0015]
In the above-described configuration, it is preferable that the position of each of the two bulging portions formed at the left and right end portions be provided with means capable of fine adjustment on at least the left and right directions on the mat body.
[0016]
According to a preferred example, the RF coil for the head is a QD coil, and the head mat is placed on the inner peripheral surface of the QD coil .
[0017]
Further, preferably, the marker has at least two indicating both end portions of the sensitivity region, and the region sandwiched between the two markers is positioned at a substantially central portion in the longitudinal direction of the mat body, and The bulge portion is positioned outside the range of the marker in the longitudinal direction. As a result, since the bulge portion on the mat body is displaced from the sensitivity region, the head mat is reversed even if it is used in a so-called reversible manner. The part can be almost certainly matched to the sensitivity region. In other words, the bulging portion does not get in the way when reversible.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the head mat of the present invention will be described with reference to the accompanying drawings.
[0019]
In the following embodiments and modifications thereof, a mat used at the time of head imaging by a magnetic resonance imaging apparatus is exemplified as the head mat of the present invention. An example in which a QD coil is used as the RF coil will be given. However, the head mat according to the present invention is not limited to such magnetic resonance imaging or a QD coil.
[0020]
For example, such a head mat can be used at the time of imaging with an X-ray CT scanner. Further, in the case of magnetic resonance imaging, when a surface coil is used instead of the QD coil, such a head mat may be laid. Furthermore, the present invention is not necessarily limited to the case of imaging of the head, and when imaging other parts such as the chest, abdomen, and lower limbs, such a head mat may be laid on the head.
[0021]
A head mat according to an embodiment of the present invention will be described with reference to FIGS.
[0022]
This head mat is used together with a QD coil as a head RF coil when the head is imaged by a magnetic resonance imaging apparatus.
[0023]
In FIG. 1, a QD coil assembly 11 is placed on a bed of a magnetic resonance imaging apparatus (not shown). The QD coil assembly 11 includes a plastic lower unit 11L and an upper unit 11U, both of which are detachable via a hinge mechanism 11H provided on one side surface in the longitudinal direction (Z-axis direction). Are connected.
[0024]
The lower unit 11L is formed such that the lower surface thereof is flat and the upper surface forms a substantially U-shaped surface. The upper unit 11U has an upper surface and a lower surface formed on a substantially U-shaped outer peripheral surface. For this reason, both units 11U and 11L cooperate to form a cylindrical bore. The size of both the units 11U and 11L is such that the bore can surround the head of the subject (here, the entire upper part from the upper part of the neck of the subject) leaving a gap of an appropriate distance. Is set.
[0025]
The upper unit 11U is also provided with a window 12 penetrating through the front and back at the center. On the edge of the window 12, a projector marker 13 for alignment is marked. In both the upper and lower units 11U and 11L, a conductor 14 forming a QD coil consisting of a coil segment pair with a spatial phase difference of 90 degrees is disposed inside. They are electrically connected to each other through an installed connector. The conductor 14 is finally drawn out from the lower unit 11L via the cable 15. An RF signal can be transmitted to the subject via the conductor 14 (QD coil), and an MR signal generated in the subject can be detected. By adopting the QD coil structure, the S / N ratio of the MR reception signal can be increased.
[0026]
When the QD coil assembly 11 is mounted on the head of the subject, the upper unit 11U is flipped up as shown by the phantom line in FIG. 1, and the inner peripheral surface side of the lower unit 11L is opened. After putting the head in the bore between the two units, the upper unit 11U is tilted as shown by the solid line in FIG. 1, and both the units 11U and 11L are joined.
[0027]
As shown in part in FIG. 1, a head mat 21 is disposed on the arc-shaped inner periphery of the lower unit 11 </ b> L. Here, the head mat 21 has substantially the same length as the entire length in the longitudinal direction (Z-axis direction) of the lower unit 11L, and is adapted to the degree of arc of the inner peripheral portion of the lower unit 11L. It is formed in a curved substantially plate shape.
[0028]
Specifically, as shown in FIG. 2, the head mat 21 includes a mat body 22 in which a plate-like sponge material is processed into an arc shape. Pads 23 in which the mat body is inflated are disposed at one end in the longitudinal direction (Z-axis direction) on the upper surface (curved inner peripheral surface) of the mat body 22 and at both ends in the short direction (X-axis direction). , 24 are integrally formed. Since the pads 23 and 24 form an abutting body that abuts against the left and right neck muscles on the back side of the subject's head, the pad position is appropriately determined so that it can be adapted to as many neck muscles as possible. .
[0029]
The pads 23 and 24 have a substantially triangular cross section (XY cross section) perpendicular to the longitudinal direction. For this reason, a surface SF in which the pads 23 and 24 are connected via the upper surface of the mat body 22 forms a recess 25 that smoothly falls from both pads. In other words, by accurately determining the pad position, the recess 25 has an accurate size and shape for a large number of subjects.
[0030]
Another feature of the pads 23 and 24 is the length in the longitudinal direction (Z-axis direction). That is, since the head mat 21 has a so-called reversible structure that can be used by reversing the position in the longitudinal direction by 180 degrees, the length of the pads 23 and 24 in the longitudinal direction is made possible. The length L (see FIG. 2) is set shorter. As a mode of this short, it is the size which does not start on the markers M1-M3 (refer FIG. 2, 3) showing the sensitivity area | region of the QD coil mentioned later.
[0031]
The mat body 22 is covered with a cover 26 made of, for example, vinyl together with the pads 23 and 24 (see FIGS. 2 and 3). Markers M1 to M3 based on three lines representing the sensitivity region RG of the QD coil are marked on the curved inner peripheral surface of the cover 26 as shown in FIG. Of these three markers, the markers M1 and M3 at both ends in the longitudinal direction represent almost both ends of the sensitivity region RG, and the middle marker M2 represents the approximate center of the sensitivity region RG having the maximum signal value.
[0032]
Here, as shown in FIG. 1, the lower limb side end surface of the lower unit 11L of the lower unit 11L of the QD coil assembly 11 is used by aligning the lower limb side end surface of the head mat 21. Markers M1 to M3 are imprinted on the cover 26 in the aligned state. For this reason, for example, the operator can adjust the head position in the body axis direction so that the part to be scanned in the head matches the marker M2.
[0033]
By configuring the head mat 21 in this way, when the QD coil assembly 11 is mounted, the left and right pads 23 and 24 are placed on the left and right neck portions on the back side of the subject's head HD as shown in FIG. To fit. Since the concave portion 25 is formed between the pads 23 and 24, three points (three portions) of the concave portion 25 and the pads 23 and 24 fit the neck portion, and the movement of the head HD, particularly in the left-right direction. The movement of the is reliably suppressed. For this reason, movement of the head during scanning is suppressed, artifacts are reduced, and image quality is improved.
[0034]
Further, since the entire mat body 22 is formed of a flexible member, the recess 25 between the pads 23 and 24 can be formed wider in advance, for example. Even with a subject having a thick neck, the neck can be reliably and softly supported by the wide concave portion 25 and the left and right pads 23, 24. On the contrary, even if the subject has a thin neck, the pads 23 and 24 are moved inward due to their own weight, and the neck can be reliably and softly supported by the recess 25 and the left and right pads 23 and 24. On the other hand, the recess 25 between the pads 23 and 24 may be formed narrow in advance. In this case, since the left and right pads 23 and 24 have a predetermined height if the subject has a thick neck, the neck can be reliably and softly supported by the pads 23 and 24. On the contrary, when the subject has a narrow neck, the neck can be reliably and softly supported by the recess 25 and the left and right pads 23 and 24. That is, in any case, the difference in the size of the head (neck) can be absorbed and supported by the recess 25 and the pads 23 and 24 (bulges) at both ends thereof. Therefore, this head mat 21 is for everyone, which can cope with an unspecified number of head scans.
[0035]
This also almost eliminates the situation where the operator has to change the size of the mat in accordance with the size of the subject's head. Therefore, the use of the head mat 21 does not increase the operational burden on the operator.
[0036]
On the other hand, since the markers M1 to M3 representing the sensitivity region RG are written on the cover 26, the position in the head to be scanned can be accurately positioned in the sensitivity region of the RF coil. By this. Repositioning and rescanning between the head and the RF coil can be remarkably reduced, so that the trouble of reworking is unnecessary, and positioning can be performed more easily and accurately. Further, the performance of the RF coil (QD coil) can be maximized, and an MR image with good image quality can be obtained. Therefore, it can contribute to improvement of diagnostic ability.
[0037]
Further, for a patient who complains of a symptom such as a neck pain due to injury or the like, the head mat 21 can be reversed 180 degrees with respect to its longitudinal direction (in a reversible manner). As a result, it can be used in substantially the same manner as the conventional mat shown in FIG. At this time, the positions of the pads 23 and 24 are brought close to one end in the longitudinal direction (Z-axis direction) and separated from the sensitivity region RG (see FIG. 4). For this reason, even when it must be used in a reversible manner, it is possible to eliminate the inconvenience that the pads 23 and 24 are in the way and the desired scan site cannot be matched with the sensitivity region RG.
[0038]
The head mat according to the present invention is not limited to the structure described above. For example, as shown in FIG. 5, the mat body 22 and the pads 23 and 24 may be detachable from each other using, for example, velcro tapes 27a and 27b. At this time, the position markers P1 to Pn may be written so that the positions of the pads 23 and 24 in the longitudinal direction (Z-axis direction) and the short direction (X-axis direction) can be finely adjusted. With the cover 26 removed, the positions of the pads 23 and 24 can be easily finely adjusted based on the position markers P1 to Pn. In addition, you may employ | adopt another structure for the attachment or detachment structure of these pads 23 and 24. FIG.
[0039]
Moreover, since the member which forms the mat for the head of the present invention is primarily a pillow function that softly supports the head, from that point of view, if there is flexibility, plastic, Esafoam (trade name), etc. May be used.
[0040]
Furthermore, the head mat of the present invention can adopt a structure that does not use a cover that covers the mat body, and can also be a structure that uses a cover but does not attach a marker for the sensitivity region to the cover. The marker for the sensitivity region may also be configured to be directly attached to the mat body. Furthermore, when using a cover, you may attach a nonmagnetic zipper to a cover.
[0041]
Furthermore, in the present invention, as described above, regarding the range of use of the head mat, there is no intention to limit the imaging modality to the magnetic resonance imaging apparatus, and there is no intention to limit the RF coil to the QD coil. . As described above, the head mat of the present invention can be widely used in various modes.
[0042]
【The invention's effect】
As described above, according to the present invention, the head mat is formed of a flexible member so that the mat main body is formed, and the mat end positioned on the head neck side on the mat main body is flexible. Since the bulges are formed of a flexible material, recesses are formed between the bulges, and the backs of the necks (ie, the heads) of a large number of subjects with different sizes are surely secured between the recesses and the bulges. In addition, the present invention provides a head mat suitable for medical imaging by a magnetic resonance imaging apparatus that fits a large number of subjects and functions as a pillow and suppresses inadvertent movement of the head. be able to.
[0043]
Further, according to the head mat of the present invention, one of the mats fits a large number of subjects, so that the operator is not burdened with operations related to mat replacement or the like.
[0044]
Furthermore, according to the head mat of the present invention, since the marker representing the sensitivity region of the RF coil can be attached to the mat, positioning of the patient head and the RF coil can be performed easily and more accurately. .
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a state in which a head mat according to an embodiment of the present invention is mounted on a QD coil assembly.
FIG. 2 is a perspective view showing a mat body and a pad in a head mat.
FIG. 3 is a perspective view showing an overview of a head mat.
FIG. 4 is a diagram illustrating a usage state of the head mat.
FIG. 5 is a perspective view for explaining another example of the head mat according to the present invention, explaining a mat body / pad attachment / detachment mechanism.
FIG. 6 is a perspective view illustrating an example of a conventional head mat.
FIG. 7 is a perspective view for explaining another example of a conventional head mat.
[Explanation of symbols]
11 QD coil assembly (RF coil assembly)
11U, 11L Upper, lower unit 21 Head mat 22 Mat body 23, 24 Pad (bulging part)
25 Recess 26 Cover 27a, 27b Velcro (fine adjustment means)
M1 to M3 Sensitivity area markers

Claims (6)

In head mat to be used for imaging by magnetic resonance imaging apparatus have laid under the head of the subject with a head RF coil of the magnetic resonance imaging apparatus,
A mat body formed of a flexible member ;
The people left respectively of the mat end is positioned on the head neck side on the mat body, and bulges formed by members with a flexible,
A cover that covers the mat body and the bulge, and has a marker that represents a sensitivity region of the RF coil for the head;
Head mat, characterized in that it is provided with a.   The head mat according to claim 1, further comprising means capable of finely adjusting the positions of the two bulge portions formed at the left and right end portions at least in the left-right direction on the mat body. Mat for the head to play. The head mat according to claim 1 , wherein the head RF coil is a QD coil, and the head mat is placed on an inner peripheral surface of the QD coil. . 2. The head mat according to claim 1 , wherein the marker has at least two indicating both ends of the sensitivity region, and a region sandwiched between the two markers is a substantially central portion in a longitudinal direction of the mat body. And the bulging portion is located outside the range of the marker in the longitudinal direction. The head mat according to claim 1, wherein a plurality of markers are attached to the cover, and one of the plurality of markers represents an end of a sensitivity region. The head mat according to claim 1, wherein a plurality of markers are attached to the cover, and one of the plurality of markers represents a substantially center of a sensitivity region.

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