JP7183059B2 - Magnetic resonance imaging device - Google Patents

Description

An embodiment of the present invention relates to a magnetic resonance imaging (MRI) apparatus.

Conventionally, a frame having a bore forming an examination space is provided, an RF (Radio Frequency) magnetic field is applied to the subject placed in the bore, and an image is obtained based on MR signals generated from the subject under the influence of the RF magnetic field. MRI equipment is known that generates Such an MRI apparatus is sometimes provided with a lighting fixture for illuminating the inside of the bore so that the subject does not feel uneasy when the inside of the bore becomes dark. However, in general, lighting equipment emits noise due to electrical control, which may adversely affect images, and is difficult to implement.

JP 2015-66125 A JP 2017-80298 A JP 2008-149118 A JP 2010-124942 A JP 2013-163018 A

The problem to be solved by the present invention is to control the illumination in the bore without relying on electrical control.

An MRI apparatus according to an embodiment includes a pedestal having a bore, a top plate movable into the bore from outside the bore, and a light source provided in the bore for illuminating the interior of the bore. The top plate has a light guide portion that transmits or reflects the light emitted from the light source. When the top plate is positioned outside the bore, the light emitted from the light source passes through the light guide portion. When the light reaches the inside of the bore without passing through and the top plate is positioned inside the bore, the light emitted from the light source passes through the light guide section.

FIG. 1 is a diagram showing an overall configuration example of an MRI apparatus according to this embodiment. FIG. 2 is a diagram showing illumination control inside the bore in the MRI apparatus according to this embodiment. FIG. 3 is a diagram showing illumination control inside the bore in the MRI apparatus according to this embodiment. FIG. 4 is a diagram showing a first example of the light guide part of the top plate of the MRI apparatus according to this embodiment. FIG. 5 is a diagram showing a first example of the light guide part of the top plate of the MRI apparatus according to this embodiment. FIG. 6 is a diagram showing a second example of the light guide part of the top plate of the MRI apparatus according to this embodiment. FIG. 7 is a diagram showing a third example of the light guide part of the top plate of the MRI apparatus according to this embodiment. FIG. 8 is a diagram showing a third example of the light guide part of the top plate of the MRI apparatus according to this embodiment.

Hereinafter, embodiments of the MRI apparatus will be described in detail with reference to the drawings. Each drawing referred to in the following description shows a conceptual configuration, and the shape and size of each component may differ from the actual product. Moreover, in each drawing, the same code|symbol is attached|subjected to the component which plays the same role.

FIG. 1 is a diagram showing an overall configuration example of an MRI apparatus according to this embodiment.

As shown in FIG. 1, the MRI apparatus 100 according to the present embodiment includes a static magnetic field magnet 1, a gradient magnetic field coil 20, a gradient magnetic field power supply 3, a whole body coil 4, a local coil 5, a transmission circuit 6, a reception circuit 7, It comprises a pedestal 8, a bed 9, an interface 10, a display 11, a memory circuit 12, and processing circuits 13-16.

A static magnetic field magnet 1 generates a static magnetic field in an examination space in which a subject S is arranged. Specifically, the static magnetic field magnet 1 is formed in a hollow, substantially cylindrical shape (including those having an elliptical cross-sectional shape perpendicular to the central axis), and an examination space on the inner peripheral side of the cylinder. to generate a static magnetic field. For example, the static magnetic field magnet 1 has a substantially cylindrical cooling container and a magnet such as a superconducting magnet immersed in a coolant (for example, liquid helium) filled in the cooling container. The static magnetic field magnet 1 may be one that generates a static magnetic field using a permanent magnet, for example.

The gradient magnetic field coil 20 generates a gradient magnetic field in the examination space in which the subject S is arranged. Specifically, the gradient magnetic field coil 20 is formed in a hollow, substantially cylindrical shape (including one having an elliptical cross-sectional shape perpendicular to the central axis), and the examination space on the inner peripheral side of the cylinder. to generate a gradient magnetic field. Here, the gradient magnetic field coil 20 has three substantially cylindrical coils laminated in the radial direction. A gradient magnetic field is generated along each of the X-axis, Y-axis, and Z-axis directions.

More specifically, the gradient magnetic field coil 20 includes three coils: an X coil for generating a gradient magnetic field coil along the X-axis direction, a Y coil for generating a gradient magnetic field coil along the Y-axis direction, and a Z coil for generating a gradient magnetic field coil along the Y-axis direction. and a Z coil for generating gradient coils along the axial direction. Here, the X-axis, Y-axis, and Z-axis constitute an apparatus coordinate system unique to the MRI apparatus 100 . For example, the X-axis is set in the horizontal direction orthogonal to the central axis of the gradient magnetic field coil 20 and the Y-axis is set in the vertical direction orthogonal to the central axis of the gradient magnetic field coil 20 . Also, the Z-axis is set along the central axis of the gradient magnetic field coil 20 .

The gradient magnetic field power supply 3 supplies a current to each of the X coil, the Y coil, and the Z coil of the gradient magnetic field coil 20 to generate a gradient magnetic field along each of the X-axis, Y-axis, and Z-axis directions. is generated in the examination space. Specifically, the gradient magnetic field power supply 3 appropriately supplies currents to the X coil, the Y coil, and the Z coil, respectively, to generate gradients along the readout direction, the phase encoding direction, and the slice direction, which are orthogonal to each other. Generate a magnetic field. Here, the axis along the readout direction, the axis along the phase encoding direction, and the axis along the slice direction constitute a logical coordinate system for defining a slice region or volume region to be imaged.

Gradient magnetic fields along each of the readout direction, the phase encoding direction, and the slice direction are superimposed on the static magnetic field generated by the static magnetic field magnet 1, thereby spatially positioning the MR signal generated from the subject S. Give information. Specifically, the gradient magnetic field in the readout direction changes the frequency of the MR signal according to the position in the readout direction, thereby imparting positional information along the readout direction to the MR signal. Further, the gradient magnetic field in the phase-encoding direction changes the phase of the MR signal along the phase-encoding direction, thereby imparting positional information along the phase-encoding direction to the MR signal. Also, the gradient magnetic field in the slice direction imparts position information along the slice direction to the MR signal. For example, the gradient magnetic field in the slice direction is used to determine the direction, thickness, and number of slice regions when the imaging region is a slice region, and is used to determine the position in the slice direction when the imaging region is a volume region. is used to vary the phase of the MR signal in response to .

The whole-body coil 4 is an RF coil that applies an RF (Radio Frequency) magnetic field to an examination space in which the subject S is placed and receives MR signals generated from the subject S under the influence of the RF magnetic field. Specifically, the whole-body coil 4 is formed in a hollow, substantially cylindrical shape (including one having an elliptical cross-sectional shape perpendicular to the central axis), and the RF pulse signal supplied from the transmission circuit 6 , an RF magnetic field is applied to the examination space on the inner peripheral side of the cylinder. The whole-body coil 4 also receives MR signals generated from the subject S under the influence of the RF magnetic field, and outputs the received MR signals to the receiving circuit 7 . For example, the whole-body coil 4 is a birdcage-type QD (quadrature) coil.

The local coil 5 is an RF coil that receives MR signals generated from the subject S. As shown in FIG. Specifically, the local coil 5 is an RF coil prepared for each part of the subject S, and is arranged near the part to be imaged when the subject S is imaged. The local coil 5 receives MR signals generated from the subject S under the influence of the RF magnetic field applied by the whole body coil 4 and outputs the received MR signals to the receiving circuit 7 . The local coil 5 may further have the function of a transmission coil that applies an RF magnetic field to the subject S. In that case, the local coil 5 is connected to the transmission circuit 6 and applies an RF magnetic field to the subject S based on the RF pulse signal supplied from the transmission circuit 6 . For example, the local coil 5 is a surface coil or an array coil composed of a plurality of surface coils.

The transmission circuit 6 outputs to the whole-body coil 4 an RF pulse signal corresponding to a resonance frequency (Larmor frequency) unique to the target nucleus placed in the static magnetic field. Specifically, the transmission circuit 6 has a pulse generator, an RF generator, a modulator, and an amplifier. A pulse generator generates a waveform of an RF pulse signal. An RF generator generates an RF signal at a resonant frequency. The modulator generates an RF pulse signal by modulating the amplitude of the RF signal generated by the RF generator with the waveform generated by the pulse generator. The amplifier amplifies the RF pulse signal generated by the modulator and outputs it to the whole-body coil 4 .

The receiving circuit 7 generates MR signal data based on the MR signals received by the whole-body coil 4 or the local coil 5 and outputs the generated MR signal data to the processing circuit 14 . Specifically, the receiving circuit 7 has a preamplifier, a detector, and an A/D (Analog/Digital) converter. The preamplifier amplifies the MR signal output from the whole-body coil 4 or the local coil 5 . The detector detects an analog signal obtained by subtracting the resonance frequency component from the MR signal amplified by the preamplifier. The A/D converter converts the analog signal detected by the detector into a digital signal to generate MR signal data, and outputs the generated MR signal data to the processing circuit 14 .

The pedestal 8 has a hollow bore 8a formed in a substantially cylindrical shape (including one having an elliptical cross-sectional shape orthogonal to the central axis), and contains the static magnetic field magnet 1, the gradient magnetic field coil 20, and the whole body body. It supports the coil 4. Specifically, the gantry 8 arranges the gradient magnetic field coil 20 on the inner circumference side of the static magnetic field magnet 1, arranges the whole body coil 4 on the inner circumference side of the gradient magnetic field coil 20, and arranges the whole body coil 4 on the inner circumference side. It supports the static magnetic field magnet 1, the gradient magnetic field coil 20, and the whole-body coil 4, respectively, with the bore 8a arranged on the side. Here, the space inside the bore 8a of the gantry 8 serves as an examination space in which the subject S is arranged when the subject S is imaged.

The bed 9 has a top plate 9a that can move from outside the bore 8a of the gantry 8 into the bore 8a. move to the inspection space formed in . For example, the top plate 9 a is installed so that its longitudinal direction is parallel to the central axis of the static magnetic field magnet 1 and is movable along the central axis of the static magnetic field magnet 1 .

Here, an example in which the MRI apparatus 100 has a so-called tunnel configuration in which the static magnetic field magnet 1, the gradient magnetic field coil 20, and the whole-body coil 4 are each formed in a substantially cylindrical shape will be described. The form is not limited to this. For example, the MRI apparatus 100 has a so-called open configuration in which a pair of static magnetic field magnets, a pair of gradient magnetic field coils, and a pair of RF coils are arranged to face each other across an examination space in which the subject S is arranged. You may have In this case, the space sandwiched by the pair of static magnetic field magnets, the pair of gradient magnetic field coils and the pair of RF coils corresponds to the bore in the tunnel configuration.

The interface 10 receives input operations for various instructions and various information from the operator. Specifically, the interface 10 is connected to the processing circuit 16 , converts an input operation received from the operator into an electrical signal, and outputs the electrical signal to the processing circuit 16 . For example, the interface 10 includes a trackball, a switch button, a mouse, a keyboard, a touch pad for performing input operations by touching the operation surface, and a display screen for setting imaging conditions and regions of interest (ROI). It is realized by a touch screen integrated with a touch pad, a non-contact input circuit using an optical sensor, an audio input circuit, and the like. In this specification, the interface 10 is not limited to having physical operation parts such as a mouse and a keyboard. For example, the interface 10 also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs the electrical signal to the control circuit.

The display 11 displays various information and various images. Specifically, the display 11 is connected to the processing circuit 16, converts various information and image data sent from the processing circuit 16 into electrical signals for display, and outputs the electrical signals. For example, the display 11 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, a touch panel, or the like.

The storage circuit 12 stores various data. Specifically, the memory circuit 12 stores MR signal data and image data. For example, the storage circuit 12 is realized by a RAM (Random Access Memory), a semiconductor memory device such as a flash memory, a hard disk, an optical disk, or the like.

The processing circuit 13 has a bed control function 13a. The bed control function 13 a controls the operation of the bed 9 by outputting electrical signals for control to the bed 9 . For example, the bed control function 13a receives an instruction from the operator via the interface 10 to move the tabletop 9a in the longitudinal direction, the vertical direction, or the horizontal direction, and controls the bed so that the tabletop 9a is moved according to the received instruction. The movement mechanism of the top plate 9a of 9 is operated.

The processing circuit 14 has a data collection function 14a. The data acquisition function 14a acquires MR signal data of the subject S by executing various pulse sequences. Specifically, the data acquisition function 14 a executes a pulse sequence by driving the gradient magnetic field power supply 3 , the transmission circuit 6 and the reception circuit 7 according to the sequence execution data output from the processing circuit 16 . Here, the sequence execution data is data representing a pulse sequence, and includes the timing and strength of the current supplied by the gradient magnetic field power supply 3 to the gradient magnetic field coil 20, and the power supplied by the transmission circuit 6 to the whole body coil 4. This information defines the strength and supply timing of the RF pulse signal, the detection timing for the receiving circuit 7 to detect the MR signal, and the like. Then, the data acquisition function 14 a receives MR signal data from the receiving circuit 7 as a result of executing the pulse sequence, and stores the received MR signal data in the storage circuit 12 . Here, the set of MR signal data received by the data acquisition function 14a is arranged two-dimensionally or three-dimensionally according to the positional information imparted by the readout magnetic field gradient, the phase-encoding magnetic field gradient, and the slice magnetic field gradient described above. As a result, it is stored in the storage circuit 12 as data forming the k-space.

The processing circuit 15 has an image generation function 15a. The image generation function 15 a generates an image based on the MR signal data stored in the memory circuit 12 . Specifically, the image generation function 15a reads the MR signal data stored in the storage circuit 12 by the data acquisition function 14a, and performs post-processing, that is, reconstruction processing such as Fourier transform on the read MR signal data. to generate the image. Further, the image generation function 15a causes the storage circuit 12 to store the image data of the generated image.

The processing circuit 16 has a main control function 16a. The main control function 16 a performs overall control of the MRI apparatus 100 by controlling each component of the MRI apparatus 100 . Specifically, the main control function 16a displays a GUI (Graphical User Interface) on the display 11 for receiving various instructions and various information input operations from the operator. The main control function 16 a controls each component of the MRI apparatus 100 according to input operations received via the interface 10 . For example, the main control function 16a receives input of imaging conditions from the operator via the interface 10 . Then, the main control function 16a generates sequence execution data based on the received imaging conditions, and transmits the sequence execution data to the processing circuit 14, thereby executing various pulse sequences. Further, for example, the main control function 16a reads image data from the storage circuit 12 and outputs it to the display 11 in response to a request from the operator.

Here, the processing circuits 13 to 16 described above are implemented by, for example, processors. In this case, the processing functions of each processing circuit are stored in the storage circuit 12 in the form of a computer-executable program, for example. Each processing circuit reads and executes each program from the storage circuit 12, thereby realizing a function corresponding to each program. Here, each processing circuit may be composed of a plurality of processors, and each processor may implement each processing function by executing a program. Also, the processing functions of each processing circuit may be appropriately distributed or integrated in a single or a plurality of processing circuits. Also, here, the single memory circuit 12 has been described as storing programs corresponding to each processing function, but a plurality of memory circuits may be arranged in a distributed manner so that the processing circuits correspond to individual memory circuits. A configuration for reading a program may be used.

The overall configuration of the MRI apparatus 100 according to this embodiment has been described above. With such a configuration, the MRI apparatus 100 according to the present embodiment has a configuration for illuminating the inside of the bore 8a so that the subject does not feel uneasy when the inside of the bore 8a becomes dark.

For example, as such a configuration, it is conceivable to use a lighting fixture such as a light or a projector. However, in general, lighting equipment emits noise due to electrical control, which may adversely affect images, and is difficult to implement.

Therefore, the MRI apparatus 100 according to this embodiment is configured to be able to control the lighting inside the bore 8a without relying on electrical control.

Specifically, the MRI apparatus 100 according to the present embodiment is provided within the bore 8a and includes a light source that illuminates the interior of the bore 8a. In addition, the top plate 9a has a light guide portion that transmits or reflects the light emitted from the light source. When the top plate 9a is positioned within the bore 8a, the light emitted from the light source passes through the light guide portion.

2 and 3 are diagrams showing illumination control inside the bore 8a in the MRI apparatus 100 according to this embodiment. Here, FIG. 2 shows illumination control when the top plate 9a is positioned outside the bore 8a, and FIG. 3 shows illumination control when the top plate 9a is positioned inside the bore 8a.

As shown in FIG. 2, in the present embodiment, a top plate 9a is supported below the bore 8a of the mount 8 along the axial direction of the bore 8a so as to be movable in the axial direction of the bore 8a. Two rails 8b are provided. Although only one rail 8b is shown in FIG. 2 for convenience of illustration, rails 8b are provided on each of the left and right sides of the pedestal 8 in the approach direction of the top plate 9a.

In this embodiment, along each of the two rails 8b provided on the pedestal 8, a plurality of light sources (not shown) are arranged continuously. Each light source illuminates the inside of the bore 8a by emitting light upward. Here, each light source is adjusted to illuminate the inner side of the bore 8a more brightly than the front side.

In addition, elongated lenses 8c are arranged along the rails 8b of the pedestal 8 so as to cover the plurality of light sources. Here, the lens 8c is adjusted so that the light emitted from each light source is diverged and widely illuminates the inside of the bore 8a from the bottom to the top.

As shown in FIG. 3, in the present embodiment, when the top plate 9a on which the subject is placed is moved into the bore 8a, the light guide portion of the top plate 9a illuminates the inside of the bore 8a. change. Specifically, the light guide section is composed of optical members such as a reflector and a lens, and changes the illumination inside the bore 8a by acting on the light emitted from the light source. Here, the light guide section continuously changes the illumination inside the bore 8a as the top plate 9a moves. For example, the light guide section changes any one of, or at least two of, the illumination intensity, the range of illumination, and the color variation of the illumination for the illumination in the bore 8a.

According to such a configuration, when the top plate 9a is positioned outside the bore 8a, the inside of the bore 8a is brightly illuminated by each light source, so that the subject's anxiety can be reduced. On the other hand, when the top plate 9a is positioned within the bore 8a, by changing the illumination within the bore 8a as the top plate 9a moves, the subject is not overly dazzled and is less anxious. An examination space can be provided. In addition, since each light source is adjusted to illuminate the inner side of the bore 8a more brightly than the nearer side, the savanna effect can reduce anxiety about the subject entering the bore 8a.

In the present embodiment, such control of lighting inside the bore 8a is performed by mechanical control, not electrical control, by the light guide provided on the top plate 9a. As a result, in this embodiment, the illumination within the bore 8a can be controlled without generating noise that adversely affects the image.

A configuration example of the light guide section of the top plate 9a of the MRI apparatus 100 according to the present embodiment will be described below. In addition, in the examples described below, the description will focus on the points that are different between the examples, and the detailed description of overlapping contents will be omitted.

4 and 5 are diagrams showing a first example of the light guide part of the top plate 9a of the MRI apparatus 100 according to this embodiment.

Here, FIG. 4 shows the configuration around the light source when the top plate 9a is positioned outside the bore 8a, and FIG. 5 shows the configuration around the light source when the top plate 9a is positioned inside the bore 8a. is shown. 4 and 5 show the configuration of the peripheral portion of one of the two rails 8b of the pedestal 8, the peripheral portion of the other rail 8b is similarly configured.

As shown in FIG. 4, in this embodiment, a plurality of light sources 8d are continuously arranged along a rail 8b provided on the lower side of a bore 8a in the pedestal 8. As shown in FIG. Each light source illuminates the inside of the bore 8a by emitting light upward. Here, for example, the light source 8d is an LED (Light Emitting Diode) or the like. In addition, an elongated lens 8c extending in the axial direction of the bore 8a is arranged on the mount 8 so as to cover the plurality of light sources 8d. Here, the lens 8c is adjusted so that the light emitted from each light source is diverged and widely illuminates the inside of the bore 8a from the bottom to the top.

Here, as shown in FIG. 4, in the first example, the pedestal 8 has a light guide plate 8e provided on the inner wall of the bore 8a. Here, the light guide plate 8e has an exit surface 8f arranged along the inner wall of the bore 8a, and an entrance surface 8g arranged at the end closer to the light source 8d. By diffusing the incident light and emitting it from the entire emission surface 8f, the light is diffused in the bore 8a.

Further, as shown in FIG. 5, in the first example, the top plate 9a has a reflector plate 9b as a light guide portion. Here, the reflecting plate 9b is provided on the top plate 9a at a position above the light source 8d when the top plate 9a is positioned within the bore 8a. The inclination of the reflective surface and the like are adjusted so that the light is reflected on the inner wall side of the .

With such a configuration, in the first example, when the top plate 9a is positioned within the bore 8a, the reflector 9b provided on the top plate 9a directs the light emitted from the light source 8d to enter the light guide plate 8e. It is reflected so that it is incident on surface 8g. Then, the light guide plate 8e diffuses the light incident from the incident surface 8g into the bore 8a by the reflector 9b. Thus, in the first example, when the top plate 9a is positioned outside the bore 8a, the entire inside of the bore 8a is brightly and widely illuminated by the direct light from the light source 8d, while the top plate 9a is positioned inside the bore 8a. At this time, the indirect light from the light guide plate 8e illuminates the range near the inner wall of the bore 8a with soft light.

FIG. 6 is a diagram showing a second example of the light guide part of the top plate 9a of the MRI apparatus 100 according to this embodiment.

Here, FIG. 6 shows the configuration around the light source when the top plate 9a is positioned within the bore 8a. Although FIG. 6 shows the configuration of the peripheral portion of one of the two rails 8b of the pedestal 8, the peripheral portion of the other rail 8b is similarly configured.

As shown in FIG. 6, in the second example, the pedestal 8 has a reflector 8h provided on the inner wall of the bore 8a. Here, the reflector 8h is arranged along the inner wall of the bore 8a, and is configured to diffuse the light within the bore 8a by reflecting the light irradiated on the surface.

Further, as shown in FIG. 6, in the second example, the top plate 9a has a lens 9c as a light guide. Here, the lens 9c is provided on the top plate 9a at a position above the light source 8d when the top plate 9a is positioned within the bore 8a. The shape of the lens surface and the like are adjusted so that the light is deflected toward the inner wall and transmitted.

With such a configuration, in the second example, the lens 9c provided on the top plate 9a directs the light emitted from the light source 8d to the surface of the reflector 8h when the top plate 9a is positioned within the bore 8a. Deflect to illuminate and transmit. As a result, the reflector 8h diffuses the light, which has been applied to the surface by the lens 9c, into the bore 8a. Thus, in the second example, when the top plate 9a is positioned outside the bore 8a, the entire inside of the bore 8a is brightly and widely illuminated by the direct light from the light source 8d, while the top plate 9a is positioned inside the bore 8a. At this time, the indirect light from the reflector 8h illuminates the range near the inner wall of the bore 8a with soft light.

7 and 8 are diagrams showing a third example of the light guide part of the top plate 9a of the MRI apparatus 100 according to this embodiment.

Here, FIG. 7 shows the configuration around the light source when the top plate 9a is positioned outside the bore 8a, and FIG. 8 shows the configuration around the light source when the top plate 9a is positioned inside the bore 8a. is shown. 7 and 8 show the configuration of the peripheral portion of one of the two rails 8b of the pedestal 8, the peripheral portion of the other rail 8b is similarly configured.

As shown in FIG. 7, in the third example, the pedestal 8 has a light guide plate 8e provided on the inner wall of the bore 8a, similar to the examples shown in FIGS. In the third example, as shown in FIG. 7, with the top plate 9a positioned outside the bore 8a, the light emitted from each light source 8d passes through the incident surface of the light guide plate 8e as well as the lens 8c. The position of the light source 8d and the shape of the light guide plate 8e are adjusted so that the light also enters the light 8g. As a result, the light guide plate 8e diffuses light into the bore 8a even when the top plate 9a is positioned outside the bore 8a.

Moreover, as shown in FIG. 8, in the third example, the top plate 9a has a half mirror 9d as a light guide. Here, the half mirror 9d is provided on the top plate 9a at a position above the light source 8d when the top plate 9a is positioned within the bore 8a. is transmitted to the inside of the bore 8a, while part of the light is reflected to the inner wall side of the bore 8a. As a result, the light guide plate 8e diffuses stronger light into the bore 8a when the top plate 9a is positioned within the bore 8a than when the top plate 9a is positioned within the bore 8a.

In the examples shown in FIGS. 7 and 8, the light emitted from each light source 8d enters both the lens 8c and the incident surface 8g of the light guide plate 8e, but the embodiment is not limited to this. do not have. For example, in the pedestal 8, a plurality of light sources 8d are alternately arranged along each rail 8b, with light sources that enter light into the lens 8c and light sources that enter light into the incident surface 8g of the light guide plate 8e. may be configured. In this case, the half mirror 9d provided on the top plate 9a, when the top plate 9a is positioned within the bore 8a, diverts part of the light emitted from the light source that enters the lens 8c to the light guide plate 8e. is configured to be reflected so as to be incident on the entrance surface 8g of the .

With such a configuration, in the third example, when the top plate 9a is positioned within the bore 8a, the half mirror 9d provided on the top plate 9a reflects part of the light emitted from the light source 8d to the lens 8c. While the light is transmitted so as to be incident on the light guide plate 8e, part of the light is reflected so as to be incident on the incident surface 8g of the light guide plate 8e. Then, the light guide plate 8e diffuses the light incident from the incident surface 8g into the bore 8a by the reflector 9b. Thus, in the third example, when the top plate 9a is positioned outside the bore 8a, both the direct light from the light source 8d and the indirect light from the light guide plate 8e illuminate the entire bore 8a brightly and widely. Become. On the other hand, when the top plate 9a is positioned inside the bore 8a, the illumination is switched to only the indirect light from the light guide plate 8e, and compared to when the top plate 9a is positioned outside the bore 8a, the light guide plate The amount of light incident on the incident surface 8g of the bore 8e is increased, and the area near the inner wall of the bore 8a is illuminated with stronger indirect light.

In each example described above, for example, the light guide plate 8e and the reflector plate 8h provided on the inner wall of the bore 8a may be provided over the entire inner wall, or may be provided on a part of the inner wall. For example, the light guide plate 8e and the reflector 8h are provided on the left and right portions of the top plate 9a in the approach direction, avoiding the upper portion of the inner wall of the bore 8a. As a result, for example, when the subject is placed in the bore 8a in a supine state, both sides of the subject are illuminated with soft indirect light, and the visual field of the subject is adjusted so as not to cause discomfort due to glare. It becomes possible to suppress the illumination of the upper part of the entering bore 8a.

Further, in each of the examples described above, the range of illumination within the bore 8a changes depending on whether the top plate 9a is positioned outside the bore 8a or when the top plate 9a is positioned outside the bore 8a. However, the embodiment is not limited to this.

For example, the illuminance within the bore 8a may be varied. In that case, for example, the transmittance or reflectance of the light guide plate 8e and the reflector 8h is adjusted so as to change the illuminance inside the bore 8a. For example, the light guide plate 8e and the reflector 8h are adjusted in transmittance or reflectance so as to reduce the illuminance of the light emitted from the light source 8d. Here, the transmittance or reflectance of the light guide plate 8e and the reflector 8h may not necessarily be uniform throughout, and may be appropriately changed at each portion according to the position within the bore 8a. . For example, the transmittance or reflectance of each portion of the light guide plate 8e and the reflector 8h may be adjusted so that the space within the bore 8a has uniform brightness.

Further, for example, the lighting in the bore 8a may be changed in color. In that case, for example, the light guide plate 8e and the reflector 8h are colored so as to change the color of illumination in the bore 8a. For example, the light guide plate 8e and the reflector 8h are colored so as to change the light emitted from the light source 8d to a lighter color. Further, for example, the light guide plate 8e and the reflector plate 8h are appropriately arranged so that patterns and patterns (dots, wave patterns, planetarium-like patterns, etc.) that make the subject feel relaxed and relieved are raised on the surface. It may be patterned. Alternatively, for example, instead of coloring the light guide plate 8e and the reflector 8h, the lens 8c provided on the mount 8 may be colored.

The change in illuminance, the change in range of illumination, and the change in color of illumination described here may be performed independently, or at least two of them may be performed in combination. can be

As described above, in this embodiment, the MRI apparatus 100 is provided within the bore 8a and includes a light source that illuminates the interior of the bore 8a. In addition, the top plate 9a has a light guide portion that transmits or reflects the light emitted from the light source. When the top plate 9a is positioned within the bore 8a, the light emitted from the light source passes through the light guide portion.

According to such a configuration, in the present embodiment, the lighting inside the bore 8a is controlled mechanically by the light guide section provided on the top plate 9a. Therefore, in this embodiment, the illumination inside the bore 8a can be controlled without electrical control. As a result, in this embodiment, the illumination within the bore 8a can be controlled without generating noise that adversely affects the image. In addition, it is possible to provide an examination space at a low cost, which is not too dazzling for the subject and alleviates anxiety.

In addition, the term "processor" used in the description of each embodiment described above is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC) , programmable logic devices (e.g., Simple Programmable Logic Devices (SPLDs), Complex Programmable Logic Devices (CPLDs), and Field Programmable Gate Arrays (FPGAs)), etc. means Here, instead of storing the program in the memory circuit, the program may be configured to be directly embedded in the circuit of the processor. In this case, the processor implements its functions by reading and executing the program embedded in the circuit. Further, each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize its function. good.

Here, the program executed by the processor is pre-installed in a ROM (Read Only Memory), a storage circuit, or the like and provided. This program is a file in a format that can be installed in these devices or in a format that can be executed, such as CD (Compact Disk)-ROM, FD (Flexible Disk), CD-R (Recordable), DVD (Digital Versatile Disk), etc. may be provided on a computer readable storage medium. Also, this program may be provided or distributed by being stored on a computer connected to a network such as the Internet and downloaded via the network. For example, this program is composed of modules including each functional unit described above. As actual hardware, the CPU reads out a program from a storage medium such as a ROM and executes it, so that each module is loaded onto the main storage device and generated on the main storage device.

According to at least one of the embodiments described above, the illumination inside the bore can be controlled without electrical control.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

100 Magnetic Resonance Imaging (MRI) Apparatus 8 Base 8a Light Source 8e Light Guide Plate 8h Reflector 9 Bed 9a Top Plate 9b Reflector (first example of light guide section)
9c lens (second example of light guide)
9d half mirror (third example of light guide)

Claims (6)

a cradle having a bore;
a top plate movable into the bore from outside the bore;
a light source provided within the bore for illuminating the bore;
The top plate has a light guide portion that transmits or reflects the light emitted from the light source, and when the top plate is positioned outside the bore, the light emitted from the light source passes through the light guide portion. When the light reaches the bore without passing through and the top plate is positioned in the bore, the light emitted from the light source passes through the light guide section.
Magnetic resonance imaging equipment. The light guide unit continuously changes illumination in the bore as the top plate moves.
The magnetic resonance imaging apparatus according to claim 1. the change in illumination within the bore is any one or a combination of at least two of a change in illumination intensity, a change in range of illumination, and a change in color of illumination;
3. The magnetic resonance imaging apparatus according to claim 2. The mount has a light guide plate provided on the inner wall of the bore,
The light guide part reflects the light emitted from the light source so as to be incident on the incident surface of the light guide plate when the top plate is positioned in the bore,
The light guide plate diffuses the light incident from the incident surface into the bore by the light guide section.
A magnetic resonance imaging apparatus according to any one of claims 1 to 3. The pedestal has a reflector provided on the inner wall of the bore,
When the top plate is positioned within the bore, the light guide unit deflects the light emitted from the light source so as to irradiate the surface of the reflector plate and transmits the light,
the reflector diffuses the light irradiated to the surface by the light guide into the bore;
A magnetic resonance imaging apparatus according to any one of claims 1 to 3. The light source is adjusted to illuminate the inner side of the bore more brightly than the front side.
The magnetic resonance imaging apparatus according to any one of claims 1-5.

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