Medical image diagnostic apparatus and magnetic resonance imaging apparatus

According to one embodiment, a medical image diagnostic apparatus includes a gantry and a screen. The gantry for medical imaging includes a bore. The screen is insertable into the bore. A predetermined image is projected by a projector on the screen. The screen forms a shape that enables light generated by the projector to arrive at an inner wall of the gantry.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-214742, filed Oct. 30, 2015, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a medical image diagnostic apparatus and a magnetic resonance imaging apparatus.

BACKGROUND

A magnetic resonance imaging apparatus includes a gantry equipped with an imaging mechanism such as a magnet. A bore having a substantially hollow shape is formed in the gantry. MR (magnetic resonance) imaging is performed in a state in which a patient is inserted inside a bore. A gantry having a relatively large bore diameter has been developed, but not a few patients feel stress against an MR examination due to MR imaging time requires a long period of time, noise during driving of the gantry, and a sense of pressure and a sense of blockage inside a bore.

DETAILED DESCRIPTION

In general, according to one embodiment, a medical image diagnostic apparatus includes a gantry and a screen. The gantry for medical imaging includes a bore. The screen is insertable into the bore. A predetermined image is projected by a projector on the screen. The screen forms a shape that enables light generated by the projector to arrive at an inner wall of the gantry.

The following technique is considered as a technique to mitigate stress during an MR examination. Examples of the technique include: 1. a goggle-type head-mounted display; 2. installation of a liquid crystal monitor on a ceiling or wall of an examination room; and 3. a head coil attached with a mirror to show an image on a liquid crystal monitor arranged at the rear side of a gantry. However, a patient feels a sense of pressure and a sense of blockage as the head-mounted display is attached to the patient in the case of Technique 1. It is difficult to view an image on the liquid crystal monitor if a patient's head enters a gantry in the case of Technique 2. It is possible to view the image through the mirror mounted to the head coil during MR imaging, and thus, it is possible to mitigate the sense of blockage inside the bore in the case of Technique 3. However, it is necessary to attach the mirror to each head coil. In addition, the mirror is attached to a gap between the head coils covering the head, and thus, the patient hardly feels an extent of the image. In addition, the liquid crystal monitor is installed at the rear side of the gantry and does not hide the front of the gantry, and thus, the patient can visually recognize the bore easily when being outside the gantry before the MR imaging, and hardly dispels a sense of being inside the bore even if watching the image through the mirror using a head coil after then. Further, a positional relationship between the mirror and the liquid crystal monitor is changed along with movement of a couch top, and thus, the patient still feels a sense of passing inside the bore even when viewing the image on the liquid crystal monitor through the mirror during the movement of the couch top.

Further, an image of the liquid crystal monitor is reflected only in a range of the mirror in the case of Technique 3, and thus, it is difficult to sufficiently satisfy a viewing angle range of the patient with the video. In addition, structures that support an RF coil and the mirror or the like are incorporated in a region except for the image within the viewing angle range of the patient, and thus, this technique is insufficient to provide an examination space that improves anxiety of the patient during an examination and relaxes the patient. In particular, there is a case in which the patient having claustrophobia or the like feels anxiety against a narrow bore space itself in the magnetic resonance imaging apparatus.

Hereinafter, a description will be given regarding a medical image diagnostic apparatus and a magnetic resonance imaging apparatus according to the present embodiment with reference to the drawings.

FIG. 1is a diagram illustrating a configuration of a medical image diagnostic system1that includes a medical image diagnostic apparatus10according to the present embodiment. As illustrated inFIG. 1, the medical image diagnostic system1includes the medical image diagnostic apparatus10, a projector100, and a projector control apparatus200which are connected in a wired or wireless manner to be capable of communicating with each other. The medical image diagnostic apparatus10includes a gantry11, a couch13, a movable screen apparatus15, and an imaging control unit17. For example, the gantry11, the couch13, and the movable screen apparatus15are installed in the examination room, and the imaging control unit17is installed in a control room adjacent to the examination room. The gantry11is equipped with a mechanism configured to realize medical imaging. A bore having a hollow shape is formed in the gantry11. That is, the gantry11for medical imaging includes the bore. The couch13is installed at the front side of the gantry11. The couch13supports a couch top on which a patient P is placed to be movable. The couch13moves the couch top according to control through the gantry11, a console and the like. The movable screen apparatus15is movably provided in the bore of the gantry11. The projector100is installed at the front side or the rear side of the gantry11. An image from the projector100is projected on the movable screen apparatus15.

The projector control apparatus200is a computer apparatus that controls the projector100. The projector control apparatus200supplies data relating to the image as a projection target to the projector100. The projector100projects the image corresponding to the data supplied from the projector control apparatus200on a screen of the movable screen apparatus15. For example, a liquid crystal system, a digital light processing (DLP) system, a liquid crystal on silicon (LCOS) system, a grating light valve (GLV) system, or the like is preferably used as the projector100. In this case, at least a display device and a light source are mounted to the projector100. The display device displays the image corresponding to the data supplied from the projector control apparatus200. The light source irradiates the display device with light directly or indirectly via an optical system. The light (hereinafter, referred to as projected light) passing through or reflected by the display device is emitted to the outside of the projector100directly or indirectly via the optical system. When the movable screen apparatus15is irradiated with the projected light, the image corresponding to the projected light is projected on the movable screen apparatus15.

The imaging control unit17functions as a hub of the medical image diagnostic apparatus10. For example, the imaging control unit17controls the gantry11in order to perform the medical imaging. In addition, the imaging control unit17reconstructs a medical image relating to the patient P based on raw data collected by the gantry11in the medical imaging. Incidentally, the imaging control unit17may be configured to be capable of controlling the projector100via the projector control apparatus200. In addition, the imaging control unit17supplies data relating to an image as a projection target to the projector100. In this case, the projector100projects the image corresponding to the data supplied from the imaging control unit17on the screen of the movable screen apparatus15.

Incidentally, the configuration of the medical image diagnostic system1according to the present embodiment is not limited only to the above-described configuration. For example, the projector control apparatus200is not necessarily provided in the medical image diagnostic system1as long as the imaging control unit17has the above-described function of controlling the projector100according to the projector control apparatus200.

The medical image diagnostic system1according to the present embodiment can enhance dwelling ability inside the bore during the medical imaging according to the medical image diagnostic apparatus10by utilizing the projector100and the movable screen apparatus15. An apparatus that can image the patient P using the gantry11in which the bore is formed may be used as the medical image diagnostic apparatus10according to the present embodiment. To be specific, a single modality such as a magnetic resonance imaging (MRI) apparatus, an X-ray computed tomography (CT) apparatus, a positron emission tomography (PET) apparatus, and a single photon emission computed tomography (SPECT) apparatus can be applied as the medical image diagnostic apparatus10according to the present embodiment. Alternatively, a combined modality such as an MR/PET apparatus, a CT/PET apparatus, an MR/SPECT apparatus, and a CT/SPECT apparatus may be applied as the medical image diagnostic apparatus10according to the present embodiment. However, the medical image diagnostic apparatus10according to the present embodiment is assumed to be a magnetic resonance imaging apparatus10in order to give the following description in detail. In addition, the medical image diagnostic system1, which includes the magnetic resonance imaging apparatus10, the projector100, and the projector control apparatus200, will be referred to as a magnetic resonance imaging system1.

FIG. 2is a diagram illustrating a configuration of the magnetic resonance imaging apparatus10according to the present embodiment. As illustrated inFIG. 2, the magnetic resonance imaging apparatus10includes the imaging control unit17, the gantry11, the couch13, and the movable screen apparatus15. The imaging control unit17includes a gradient power supply21, a transmitting circuitry23, a receiving circuitry25, and a console27. The console27includes an imaging control circuitry31, a reconstruction circuitry32, an image processing circuitry33, a communication circuitry34, a display circuitry35, an input circuitry36, a main memory circuitry37, and a system control circuitry38. The imaging control circuitry31, the reconstruction circuitry32, the image processing circuitry33, the communication circuitry34, the display circuitry35, the input circuitry36, the main memory circuitry37, and the system control circuitry38are connected to be capable of communicating with each other via a bus. The gradient power supply21, the transmitting circuitry23, and the receiving circuitry25are provided separately from the console27and the gantry11. As illustrated inFIG. 2, the projector is not included in the magnetic resonance imaging apparatus10.

The gantry11includes a static magnetic field magnet41, a gradient magnetic field coil43, and an RF coil45. In addition, the static magnetic field magnet41and the gradient magnetic field coil43are housed in a housing (hereinafter, referred to as a gantry housing)51of the gantry11. A bore53having a hollow shape is formed in the gantry housing51. The RF coil45is arranged inside the bore53of the gantry housing51. In addition, the movable screen apparatus15according to the present embodiment is arranged inside the bore53of the gantry housing51.

The static magnetic field magnet41has a substantially cylindrical shape with hollow and generates a static magnetic field in a substantially cylindrical inner portion. For example, a permanent magnet, a superconducting magnet, a normal conducting magnet, or the like is used as the static magnetic field magnet41. Herein, a central axis of the static magnetic field magnet41is defined as a Z-axis, and an axis which is vertically orthogonal to the Z-axis is referred to as a Y-axis, and an axis which is horizontally orthogonal to the Z-axis is referred to as an X-axis. The X-axis, the Y-axis, and the Z-axis form a three-dimensional coordinate system orthogonal to each other.

The gradient magnetic field coil43is a coil unit which is attached to an inner side of the static magnetic field magnet41and is formed in a substantially cylindrical shape with a hollow. The gradient magnetic field coil43receives supply of current from the gradient power supply21and generates a gradient magnetic field.

The gradient power supply21supplies the current to the gradient magnetic field coil43according to control of the imaging control circuitry31. The gradient power supply21causes the gradient magnetic field coil43to generate the gradient magnetic field by supplying the current to the gradient magnetic field coil43.

The RF coil45is arranged at an inner side of the gradient magnetic field coil43and generates a high frequency magnetic field by receiving supply of a RF pulse from the transmitting circuitry23. In addition, the RF coil45receives a magnetic resonance signal (hereinafter, referred to as an MR signal), which is emitted from a target atomic nucleus present inside the patient P by receiving action of the high frequency magnetic field. The received MR signal is supplied to the receiving circuitry25in a wired or wireless manner. Incidentally, the above-described RF coil45is configured as a coil having the transmission and reception functions, but an RF coil for transmission and an RF coil for reception may be provided separately.

The transmitting circuitry23transmits the high frequency magnetic field for excitation of the target atomic nucleus present inside the patient P to the patient P via the RF coil45. Typically, proton is used as the target atomic nucleus. To be specific, the transmitting circuitry23supplies a high frequency signal (RF signal) for excitation of the target atomic nucleus to the RF coil45according to control of the imaging control circuitry31. The high frequency magnetic field generated from the RF coil45oscillates with a unique resonant frequency with respect to the target atomic nucleus and excites the target atomic nucleus. The MR signal is generated from the excited target atomic nucleus, and is detected by the RF coil45. The detected MR signal is supplied to the receiving circuitry25.

The receiving circuitry25receives the MR signal, generated from the excited target atomic nucleus via the RF coil45. The receiving circuitry25performs signal processing of the received MR signal to generate a digital MR signal. The digital MR signal is supplied to the reconstruction circuitry32in a wired or wireless manner.

The couch13is installed to be adjacent to the gantry11. The couch13includes a couch top131and a base133. The patient P is loaded on the couch top131. The base133supports the couch top131to be slidable along each of the X-axis, the Y-axis, and the Z-axis. A couch driving device135is housed in the base133. The couch driving device135receives the control of the imaging control circuitry31and moves the couch top131. Any motor such as a servomotor and a stepping motor may be used as the couch driving device135.

The imaging control circuitry31includes a processor such as a central processing unit (CPU) or a micro processing unit (MPU) and a memory such as a read only memory (ROM) and a random access memory (RAM) as hardware resources. The imaging control circuitry31controls the gradient power supply21, the transmitting circuitry23, and the receiving circuitry25in a synchronous manner based on pulse sequence information supplied from the system control circuitry38, and images the patient P at a pulse sequence according to the pulse sequence information.

The reconstruction circuitry32includes a processor such as a CPU, a graphical processing unit (GPU), and an MPU and a memory such as a ROM and a RAM as hardware resources. The reconstruction circuitry32reconstructs an MR image relating to the patient P based on the MR signal supplied from the receiving circuitry25. For example, the reconstruction circuitry32generates the MR image which is defined in a real space by performing the Fourier transform or the like on the MR signal arranged in a k-space or a frequency space. Incidentally, the reconstruction circuitry32may be realized by an application specific integrated circuit (ASIC), a field programmable logic apparatus (FPGA), another complex programmable logic device (CPLD), a simple programmable logic device (SPLD) that realizes the reconstruction function.

The image processing circuitry33includes a processor such as a CPU, a GPU, and an MPU and a memory such as a ROM and a RAM as hardware resources. The image processing circuitry33performs various types of image processing with respect to the MR image reconstructed by the reconstruction circuitry32. Incidentally the image processing circuitry33may be realized by an ASIC, an FPGA, a CPLD or an SPLD that realizes the above-described image processing function.

The communication circuitry34performs data communication with the projector control apparatus200or the projector100via a wire (not illustrated) or in a wireless manner. In addition, the communication circuitry34may perform data communication with an external apparatus such as a PACS server connected via network or the like (not illustrated). In addition, the communication circuitry34may perform data communication with a device to be described later which is attached to the movable screen apparatus15.

The display circuitry35displays various types of information. For example, the display circuitry35displays the MR image reconstructed by the reconstruction circuitry32or the MR image after being subjected to the image processing by the image processing circuitry33. In addition, the display circuitry35may display the image projected by the projector100. To be specific, the display circuitry35includes a display interface circuit and a display device. The display interface circuit converts data representing a display target to a video signal. The display signal is supplied to the display device. The display device displays the video signal representing the display target. For example, a CRT display, a liquid crystal display, an organic EL display, an LED display, a plasma display, or any arbitrary display which has been known in the technical field can be suitably used as the display device.

To be specific, the input circuitry36includes an input device and an input interface circuit. The input device receives various instructions from a user. A keyboard, a mouse, various switches, and the like can be used as the input device. The input interface circuit supplies an output signal from the input device to the system control circuitry38via a bus. Incidentally, the input circuitry36is not limited to one provided with physical operating parts such as a mouse and a keyboard. Examples of the input circuitry36include a processing circuit of an electrical signal that receives the electrical signal corresponding to an input operation from an external input device, provided separately from the magnetic resonance imaging apparatus10, and outputs the received electrical signal to various circuits.

The main memory circuitry37is a storage apparatus that stores various types of information such as a hard disk drive (HDD), a solid state drive (SSD), and an integrated circuit storage apparatus. In addition, the main memory circuitry37may be a driving device that reads and writes various types of information with respect to a portable recording medium such as a CD-ROM drive, a DVD drive, and a flash memory. For example, the main memory circuitry37stores the MR image, a control program of the magnetic resonance imaging apparatus10, and the like.

The system control circuitry38includes a processor such as a CPU and an MPU and a memory such as a ROM and a RAM as hardware resources. The system control circuitry38functions as a hub of the magnetic resonance imaging apparatus10. To be specific, the system control circuitry38reads the control program stored in the main memory circuitry37, develops the control program on the memory, and controls each unit of the magnetic resonance imaging apparatus10according to the developed control program.

Hereinafter, the magnetic resonance imaging apparatus10according to the present embodiment will be described in detail.

First, a description will be given regarding an installation environment of the magnetic resonance imaging system according to the embodiment 1 with reference toFIG. 3.FIG. 3is a diagram illustrating an example of installation environment of a magnetic resonance imaging system according to the present embodiment. As illustrated inFIG. 3, an examination room300in which the MR imaging is performed and a control room400which is adjacent to the examination room300are provided. The gantry11and the couch13are installed in the examination room300. The couch13is provided at the front side of the gantry11. The movable screen apparatus15is provided in the bore of the gantry11. The examination room300is a shielded room that can shield a leaked magnetic field from the gantry11, an electromagnetic field from the outside, and the like. A door D1, configured to allow entrance and exit, is provided in the examination room300. In addition, a door D2, configured to allow coming and going between the examination room300and the control room400, is provided between the examination room300and the control room400. The console27, the projector100, and the projector control apparatus200are installed in the control room400. The projector100is installed at the rear side of the gantry11being spaced apart from a wall500between the examination room300and the control room400. A window510through which a projected light LP is transmitted is provided in a portion of the wall500in which a projected light LP from the projector100toward the movable screen apparatus15is propagated. It is possible to propagate the projected light LP from the projector100installed in the control room400to the movable screen apparatus15of the examination room300via the window510. It is preferable to provide a door D3, configured to allow entrance and exit, in the control room400.

Incidentally, the above-described layout is illustrative, and the present invention is not limited thereto. For example, the console27and the projector control apparatus200may be installed in another room differently form the projector100although the projector100, the projector control apparatus200, and the console27are installed in the control room400in the above-described layout. In addition, the projector100may be provided in the examination room300as long as the projector100can be formed using a material that is not affected by a magnetic field. In addition, a machine room or the like, which is configured to install the gradient power supply21and the receiving circuitry25therein, may be provided in addition to the examination room300and the control room400.

Next, an exterior appearance of the gantry11will be described with reference toFIG. 4.FIG. 4is a perspective view of the gantry housing51according to the present embodiment. As illustrated inFIG. 4, the hollow bore53is formed in the gantry housing51. A rail55, which is parallel to the central axis Z of the bore53, is formed below the bore53of the gantry housing51. The rail55is a structure that guides slide of the couch top131and the movable screen apparatus15along the central axis Z. The rail55is provided on an inner wall57of the gantry housing51which is in contact with the bore53. The rail55is formed using a non-magnetic material that does not act with a magnetic field used for the magnetic resonance imaging. Herein, a direction from the couch side toward the projector side in relation to the Z-axis is defined as a positive Z-axis direction and a direction from the projector side toward the couch side is defined as a negative Z-axis direction.

Next, a structure of the movable screen apparatus15will be described with reference toFIGS. 5 to 8.FIG. 5is a perspective view of the movable screen apparatus15according to the present embodiment.FIG. 6is a side view of the movable screen apparatus15.FIG. 7is a front view of the movable screen apparatus15.FIG. 8is a perspective view of the movable screen apparatus15and the couch top131which are couple with each other.

As illustrated inFIGS. 5 to 8, the movable screen apparatus15includes a movable carriage61, a screen63, a support arm65, and a reflecting plate67. The movable carriage61is a structural body that moves along the rail55provided on the inner wall57of the gantry housing51. A wheel (not illustrated) to roll the rail55is attached to a lower part of the movable carriage61in order to enhance a traveling property of the rail55. Incidentally, the wheel is not necessarily provided as long as the movable carriage61can travel along the rail55, and a face in contact with the rail55may be formed using a material having a low coefficient of friction. The movable carriage61and the rail55are formed to enable the movable carriage61to move from an end of the bore53on the couch13side (the negative Z-direction) to an end thereof on the projector100side (the positive Z-direction). A bottom face of the movable carriage61preferably has a shape that can be fit with the rail55. When the movable carriage61and the rail55are engaged with each other, it is possible to make the rail55unnoticeable when the gantry11is viewed from the outside in a state in which the movable carriage61is arranged at the end of the bore53. The movable carriage61supports the screen63and the support arm65. The movable carriage61is formed using a non-magnetic material that does not act with a magnetic field such as resin.

As illustrated inFIG. 5, a coupling portion69, configured for coupling with the couch top131, is formed in the movable carriage61. As illustrated inFIG. 8, the movable carriage61and the couch top131are coupled using the coupling portion69. A patient fixing tool137is attached to a front portion (side in the positive Z-axis direction) of the couch top131. The patient fixing tool137fixes a head of the patient P loaded on the couch top131. The patient fixing tool137has a curved shape so as to be capable of covering an occipital part without interrupting the field of view of the patient P loaded on the back on the couch top131. That is, a sincipital-part side of the patient fixing tool137is opened. Accordingly, the patient fixing tool137can mitigate the sense of blockage of the patient P, and further, mitigate constriction of the field of view of the patient P as compared to a fixing portion that covers the entire head. The patient fixing tool137is integrally molded using a non-magnetic material such as resin using a mold having the above-described shape, for example.

As illustrated inFIGS. 5 to 8, the screen63is installed upright on the movable carriage61. The image from the projector100(not illustrated) is projected on the screen63. The screen63is provided to be tiltable with respect to the movable carriage61. To be specific, the movable carriage61is provided to be tiltable by a tilting mechanism (not illustrated) provided therein. The screen63is held to be perpendicular or have a predetermined gradient angle with respect to a front surface of the movable carriage61by adjusting a tilted angle of the screen63with respect to the front surface of the movable carriage61. As described above, the projector100is arranged on the opposite side of the couch13with the screen63interposed therebetween. Herein, a face of the screen63on the projector100side is referred to as a rear surface, and a face thereof on the couch13side is referred to as the front surface. The screen63is preferably formed using a semitransparent material in order to allow the image to be projected on the front surface thereof. Semitransparent plastic, ground glass, or the like is preferably used as such a semitransparent material. When the screen63is formed using the semitransparent material, the rear surface of the screen is irradiated with the projected light emitted from the projector100, and the image corresponding to the projected light is projected on the front surface. Accordingly, the patient P or the like can view the image, which is projected on the front surface, from the couch13side. The screen63may be a model having a planar shape or a model having a curved shape. The screen63is preferably arranged such that a concave face thereof is directed to the couch13side, that is, forms the front surface in the case of having the curved shape. When the concave face is directed to the couch13side, it is possible to cover the periphery of the rear side of the head of the patient P loaded on the couch top131with the screen63. Accordingly, it is possible to make the field of view of the patient P to be filled with the image projected on the screen63such that the patient P is immersed in the image.

FIG. 9is a diagram schematically illustrating a front face of the screen63which is arranged inside the bore53. As illustrated inFIG. 9, the screen63has an outer diameter RS which is smaller than a diameter RB of the inner wall57in contact with the bore53of the gantry housing51. When the outer diameter RS is designed to be smaller than the inner diameter RB in this manner, it is possible to insert the movable screen apparatus15inside the bore53. Incidentally, a wind flows inside the bore53from a ventilation fan (not illustrated) provided in the gantry11. When a gap G1is provided between an edge of the screen63and the inner wall57, it is possible to prevent the wind blown out from the ventilation fan from being interrupted by the screen63. The outer diameter RS is preferably designed to be smaller than the inner diameter RB by, for example, 10 mm to 50 mm. In other words, the gap G1is preferably designed to be 10 mm to 50 mm.

As illustrated inFIGS. 5 to 8, the support arm65is attached to the movable carriage61. As will be described below, the support arm65is attached to the movable carriage61to be slidable in the Z-axis direction. The support arm65supports the reflecting plate67to be arranged in a space on the front surface side of the screen63. The reflecting plate67is spaced apart from the front surface of the movable carriage61to a degree that prevents collision with the head of the patient P loaded on the couch top131in a state in which the movable carriage61and the couch top131are coupled with each other, and is supported by the support arm65. The support arm65has a shape that prevents the field of view of an external observer from being interrupted when the screen63is viewed from the outside of the gantry11. The support arm65preferably has a semi-ring shape or a semi-saddle shape which includes an arcuate portion along a contour of the screen63in order not to interrupt the field of view of the external observer as illustrated inFIGS. 5 to 8. In this case, both ends of the support arm65are attached to the side portion of the movable carriage61, and the support arm65is attached to the movable carriage61such that the arcuate portion of the support arm65is positioned in the space on the front surface side of the screen63. Incidentally, the shape of the support arm65is not limited to the above-described semi-ring or semi-saddle shape, but may have any shape as long as the reflecting plate67can be arranged in the space on the front surface side of the screen63. For example, the support arm65may be configured using a pair of arms each of which has substantially a rod shape. In this case, it is preferable when one end of the pair of arms is attached to both side portions of the movable carriage61and the other end thereof is attached to the reflecting plate67.

As illustrated inFIGS. 5 to 8, the reflecting plate67is provided at a substantially uppermost part of the support arm65. The reflecting plate67reflects the image projected on the front surface of the screen63. The reflecting plate67is formed using a non-magnetic material and may be formed using any material as long as it is possible to optically reflect a target. For example, a mirror obtained by performing aluminum vapor-deposition on acryl, a half mirror to which a dielectric film adheres, and the like may be used as the reflecting plate67. The patient P whose head is arranged on the patient fixing tool137can view the image projected on the front surface through the reflecting plate67.

The reflecting plate67is rotatably provided in the support arm65such that the patient P can manually adjust an angle of the reflecting plate67. To be specific, the reflecting plate67is provided to be rotatable about a rotation shaft RR1by a rotating mechanism (not illustrated) which is provided in the support arm65. The rotation shaft RR1is provided to be parallel to the X-axis so as to be capable of adjusting a direction of the reflecting plate67with respect to the front surface of the screen63, for example. To be more specific, the support arm65may be provided at least to be switchable between a first angle configured for a first projection format and a second angle configured for a second projection format which will be described later. The first projection format is a format to view the image of the screen63without the intervention of the reflecting plate67from the outside of the gantry11. Thus, the first angle of the reflecting plate67according to the first projection format is preferably set to be, for example, substantially horizontal to an angle that does not interrupt the field of view of the patient P or the like present at the outside of the gantry11. The second projection format is a format to view the image through the reflecting plate67inside the bore53. Thus, the second angle of the reflecting plate according to the second projection format is preferably set to be an arbitrary angle between horizontal and vertical depending on physique of the patient P serving as an observer.

A sliding mechanism71of the support arm65is preferably provided in the movable carriage61in order to adjust the position of the reflecting plate67in relation to the Z-axis.FIG. 10is a diagram illustrating a side face of the movable screen apparatus15of which the support arm65inFIG. 6is slid in relation to the Z-axis. As illustrated inFIGS. 6 and 10, a guide611, which guides the slide of the support arm65along the Z-axis, is formed on the movable carriage61in the sliding mechanism71. The guide611is provided along the Z-axis on both the side faces of the movable carriage61in order to avoid contact with the support arm65and the screen63. The guide611may be realized in any mode, and, for example, is realized by a void provided on the side face of the movable carriage61along the Z-axis. As illustrated inFIGS. 6 and 11, a wheel651is preferably provided in a base portion of the support arm65facing the guide611in order to enhance a sliding performance of the support arm65. When the sliding mechanism71is provided, a medical professional such as a doctor, a technician, and a nurse, the patient P and the like can cause the reflecting plate67to approach or be spaced apart from the screen63by pushing or pulling the support arm65in the Z-axis direction. Accordingly, it is possible to adjust the position of the reflecting plate67in relation to the Z-axis direction.

Incidentally, the sliding mechanism71is realized using the guide611provided in the movable carriage61and the wheel651provided in the support arm65in the above description. However, the present embodiment is not limited thereto. Any mechanism may be used as the sliding mechanism71according to the present embodiment as long as the support arm65is relatively slidable with respect to the movable carriage61. For example, it may be configured such that a guide is provided in the support arm65along the Z-axis, and a wheel to travel the guide is provided in the movable carriage61. In addition, the sliding mechanism71may be realized using a ball screw, a slide rail, or the like.

FIG. 11is a simple side view of the movable screen apparatus15which is arranged inside the bore53of the gantry11. As illustrated inFIG. 11, the movable carriage61of the movable screen apparatus15is slidably provided in the rail55. Typically, a driving device is not mounted to the movable screen apparatus15. The movable screen apparatus15slides to be interlocked with slide of the couch top131caused by the couch driving device135. Incidentally, the movable screen apparatus15can also slide in relation to the Z-axis by being pushed and pulled by the patient P, a medical professional or the like.

The screen63is insertable into the bore53and is formed such that the light generated by the projector100can arrive at the inner wall57of the gantry housing51in relation to the bore53. To be specific, the outer diameter RS of the screen is smaller than an inner diameter RB of the bore53as illustrated inFIG. 9. In addition, the light emitted from the projector100is emitted to a region including the inner diameter RB of the bore53. Accordingly, the projection light emitted from the projector100is projected on the screen63and the inner wall57of the gantry housing51. In other words, a projected image projected from the projector100includes a first region projected on the screen63and a second region projected on the inner wall57of the gantry housing51in relation to the bore53. The projected image may be a moving image or a still image. In addition, the projected image may be a moving image or a still image. In addition, image content of the projected image may be a moving image or a still image having, for example, a relaxation effect, or examination support information such as precautions during an examination and remaining time until examination end time. The light relating to the image for the second region passes through the gap (G1inFIG. 9) between the bore and the screen. Hereinafter, the above-described content will be described in detail with reference to the drawings.

FIG. 12is a side view illustrating an example of a cross section of the magnetic resonance imaging system1viewed from a side face thereof. As illustrated inFIG. 12, the screen63is formed so as to enable the projection light LP emitted from the projector100to arrive at the inner wall57(a top wall) of the gantry housing51. Accordingly, the projection light LP is projected on the screen63and the inner wall57of the gantry housing51as illustrated inFIG. 12. An image12I inFIG. 12is an image projected on the screen63and corresponds to the first region of the projected image.

As illustrated inFIG. 12, the image12I projected on the screen63is arranged in a region (hereinafter, referred to as a center region) Iwc including a center of a viewing angle range12VA, which is immediately above the patient P, via the reflecting plate67. InFIG. 12, the projection light LP corresponding to a second region Re2is the projection light (hereinafter, referred to as leakage light) which has passed through the gap G1between an edge of the screen63and the inner wall57of the gantry housing51. The leakage light arrives at, for example, end portions (Iw1and Iw2) of the viewing angle range12VA on the inner wall57of the gantry housing51.

For example, the leakage light arrives at a range (hereinafter, referred to as a leakage light arrival range) from the screen63to the vicinity of the shoulder of the patient P in the inner wall57of the gantry housing51. That is, the screen63forms the projection light LP such that the leakage light arrives at the leakage light arrival range of the inner wall57of the gantry housing51. The leakage light arrival range depends on a shape of the screen. For example, the leakage light arrival range formed by a screen having a shape is configured of a major arc and a chord and having the chord positioned at an upper end is larger than a leakage light arrival range formed by the screen63having a circular shape as illustrated inFIG. 9.

FIG. 13is a top view of the patient P arranged inside the bore53viewed from top. As illustrated inFIG. 13, the screen63is formed so as to enable the projection light LP to arrive at the inner wall57(a side wall) of the gantry housing51. The image corresponding to the second region Re2is projected on the inner wall corresponding to the viewing angle range13VA at the side face of the patient P. The leakage light arrival range corresponding to the viewing angle range13VA inFIG. 13is determined depending on the gap (G1inFIG. 9), which is a difference between the outer diameter RS of the screen63and the inner diameter RB of the bore53of the gantry housing51and depending on a distance from the projector100to the screen63. A range indicated by LLAR inFIG. 13corresponds to the leakage light arrival range.

FIG. 14is a diagram illustrating an example of the projected image which is visually recognized by the patient P or the like. InFIG. 14, an inner circle Ic corresponds to the edge of the screen63. An image in a region inside the inner circle Ic inFIG. 14corresponds to the first region Re1projected on the screen63. A region sandwiched between an outer circle Oc and the inner circle Ic inFIG. 14corresponds to the video at the time when the leakage light arrives at the inner wall57of the gantry housing51, that is, the second region Re2.

The boundary (the inner circle Ic) between the first region Re1and the second region Re2, for example, is set in advance by the image processing circuitry33in the imaging control unit17(or the projector control apparatus200). The patient P visually recognizes the first image in the first region Re1via the screen63and the reflecting plate67and visually recognizes the second image in the second region Re2projected on the inner wall57of the gantry housing51. That is, the patient P placed on one's back on the couch top131visually recognizes the first image and the second image.

The region outside the outer circle Oc inFIG. 14corresponds to an image projected on the inner wall57on the projector100side through the screen63which is formed when the projection light not passing through the gap G1between the edge of the screen63and the inner wall57of the gantry housing51arrives at the inner wall57of the gantry housing51. As illustrated inFIGS. 12 to 14, the projected image formed by the projection light is arranged around the patient P.

According to the above-described configuration, it is possible to obtain effects to be described as follows.

According to the magnetic resonance imaging apparatus10of the present embodiment, it is possible to form the light generated by the projector100in a shape that can arrive at the inner wall57of the gantry housing51in relation to the bore53through the screen63inserted inside the bore53. That is, a projected image projected from the projector100includes the first region Re1projected on the screen63and the second region Re2projected on the inner wall57of the gantry housing51in relation to the bore53according to the magnetic resonance imaging apparatus10.

Accordingly, the patient P inserted inside the bore53of the magnetic resonance imaging apparatus10can visually recognize the image corresponding to the first region Re1via the reflecting plate67in the central region of the own viewing angle range, and visually recognize the image corresponding to the second region Re2projected on the inner wall57in the region outside the central region. That is, it is possible to set the range in which the image projected by the projector100is projected to approximate to the viewing angle range of the patient P as much as possible, and it is possible to fill substantially the entire viewing angle range of the patient P inserted inside the bore53of the magnetic resonance imaging apparatus10with the image projected from the projector100. Accordingly, the patient P inserted inside the bore53can obtain a sense of being surrounded by the image or the projection light, that is, a sense of immersion with respect to the image according to the magnetic resonance imaging apparatus10of the present embodiment.

As above, according to the magnetic resonance imaging apparatus10, it is possible to provide the environment in which the anxiety of the patient P is improved without causing the uncomfortable feeling to the patient P and the patient P can relax even when the RF coil45or the support arm65is arranged near the patient P during the MR examination with respect to the patient P. For example, it is possible to make the patient P concentrate on the projection (for example, the image projected on the screen63), which is configured to relax the feeling, during the imaging with respect to the patient P, and further, it is possible to expect that the patient P hardly recognizes being present in a small space inside the bore53.

Accordingly, it is possible to mitigate the sense of oppression inside the bore53and the stress against entering the bore53of the patient P (particularly, the patient with claustrophobia) during the MR imaging, and to improve the dwelling ability inside the bore. Further, when the movable screen apparatus15is arranged on the opposite side (the projector100side) to the couch13, the leakage light passing through the gap G1between the edge of the screen63and the inner wall57of the gantry housing51, and the image projected on the screen63are projected on the inner wall57as impression when the patient P before being subjected to examination views the gantry housing51, and thus, it is possible to give the sense of security toward the bore53to the patient P instead of impression as an inorganic tunnel.

First Modification Example

A difference between the present modification example and the embodiment is that image content (content) is different between an image (hereinafter, referred to as a first image) in a first region Re1and an image (hereinafter, referred to as a second image) in a second region Re2. The difference in image content between the first image and the second image includes at least one difference among, for example, a hue, brightness and a pattern (texture or the like).

An image processing circuitry33(or a projector control apparatus200) outputs data relating to a composite image obtained by synthesizing the first image and the second image to a projector100as data of a projected image which is projected by the projector100. Incidentally, an imaging control unit17(or the projector control apparatus200) may individually output data relating to the first image and data relating to the second image to the projector100. At this time, the projector100emits projection light corresponding to the first image and projection light corresponding to the second image at the same time.

In either case, the projected image projected by the projector100includes the first image and the second image. For example, the second image is an image that corresponds to an arbitrary visual effect which is represented using a hue, brightness, and a pattern. To be specific, the second image is an image relating to an optimal visual effect that evokes a psychological effect (such as the sense of security, relaxation, concentration on the first image, and enhanced mode) with respect to the patient P before the examination or during the examination. In addition, the second image may be a hue, brightness, or a pattern which corresponds to a pulse sequence or the like being executed with respect to the patient P.

In addition, the image processing circuitry33(or the projector control apparatus200) may create data relating to the projected image to be projected by the projector100such that at least one among the hue, brightness, and the pattern is different between the first image relating to the first region Re1and the second image relating to the second region Re2according to an operator's instruction input through an input circuitry36. In addition, the image processing circuitry33(or the projector control apparatus200) may perform trimming on data corresponding to a region outside the second region Re2in the projected image projected by the projector100.

FIGS. 15 and 16are diagrams illustrating examples in which the image content is different between the first image and the second image. InFIGS. 15 and 16, the first image in the first region Re1is the same image as the first region Re1inFIG. 14. InFIGS. 15 and 16, the second image in the second region Re2is different from the image in the first region Re1, and is the image that provides a further relaxation effect with respect to the image in the first region Re1and enables the patient P to concentrate on the image in the first region Re1. Incidentally, the projection light relating to the second image is projected on an inner wall57of a gantry housing51, and thus, may include an image obtained by reducing a strain of the projected image caused depending on an angle between a projection direction and the inner wall57, and an image pattern and color arrangement, which is associated with the first image. In addition, the projection light relating to the second image may include an image pattern and color arrangement as an environmental image that relaxes the subject P inserted inside the bore in accordance with a shape of the inner wall57of a bore53.

The second region Re2inFIGS. 15 and 16includes three different hues, for example. InFIGS. 15 and 16, a region Re2SB is light blue, a region Re2Y is yellow, and a region Re20is orange.

FIG. 17is a diagram illustrating an example of correspondence relation between the second image projected on an inner wall57of a gantry housing51and a hue in a case in which the second region Re2includes the above-described three hues. As illustrated inFIG. 17, the projection light corresponding to the region Re2SB in the second image is projected onto the vicinity of an upper side of the inner wall57. As illustrated inFIG. 17, the projection light corresponding to the region Re2Y in the second image is projected onto the vicinity of a center of the inner wall57. As illustrated inFIG. 17, the projection light corresponding to the region Re20in the second image is projected onto the vicinity of a lower part of the inner wall57.

FIG. 18is a diagram illustrating another example of the second image in the second region Re2together with the first image in the first region Re1according to the present modification example. As illustrated inFIG. 18, the second image in the second region Re2has, for example, 10 kinds of hues and a shape (spiral shape) that facilitates the patient P to concentrate on the first image. In the second region Re2inFIG. 18, the hue of the region Re2SB is light blue, a hue of a region Re2B is blue, a hue of a region Re2DB is navy, a hue of a region Re2V is purple, a hue of a region Re2P is burgundy, a hue of a region Re2R is red, the hue of the region Re20is orange, the hue of the region Re2Y is yellow, a hue of a region Re2YG is yellow green, and a hue of a region Re2G is green, respectively, in the plurality of regions partitioned into spiral shapes.

FIGS. 15 and 19are diagrams illustrating examples of the projected image in which a region tri outside the second region Re2is trimmed.FIG. 15is an image in which the region tri outside the second region Re2inFIG. 16is trimmed in advance and projected on the screen63and the inner wall57. That is, the region tri outside the second region Re2is trimmed in the data relating to the projected image corresponding toFIG. 16, and the projection light corresponding to the trimmed data is projected on the screen63and the inner wall57of the gantry housing51by the projector100.

FIG. 19is the diagram illustrating the example of the projected image in which the region tri outside the second region Re2inFIG. 18is trimmed. That is, the region tri outside the second region Re2is trimmed in the data relating to the projected image corresponding toFIG. 19, and the projection light corresponding to the trimmed data is projected on the screen63and the inner wall57of the gantry housing51by the projector100.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to provide the visual environment in which the first image reflected on the reflecting plate67and the second image reflected on the inner wall57of the gantry housing51are combined to the patient P. In addition, it is possible to apply an image corresponding to the optimal visual effect with respect to the patient P to the second image depending on a purpose according to the present modification example.

For example, the magnetic resonance imaging apparatus10according to the present modification example can change a hue (color that makes the patient P comfortable), brightness (brightness that makes the patient P comfortable), and a pattern (pattern shape that makes the patient P comfortable) of the second image in accordance with the relaxation effect (psychological action) and perform the trimming of the outer portion of the second region Re2in the projected image, the reduction of the strain in the projected image caused depending on the angle between the projection direction and the inner wall57, or the like. In addition, it is possible to project the image, which relates to the optimal visual effect with respect to the patient P, on the inner wall57of the gantry housing51as the second image before the examination or during the examination according to the present modification example. In addition, it is possible to project the projection light relating to the second image on the inner wall57of the bore53in accordance with the shape of the inner wall57of the bore53according to the present modification example. Accordingly, it is possible to more aggressively include the surroundings of the subject P, inserted inside the bore, in the image according to the present modification example. Thus, it is possible to provide the image environment in which the subject P may feel a sense of unity with the image to the subject P and to further improve the dwelling ability inside the bore of the gantry11according to the present modification example.

In this manner, it is possible to provide the enhanced relaxation effect in relation to the first image to the patient P, to provide the visual environment that prevents the patient P from feeling the bore53, and to provide the optimal visual effect with respect to the patient P before the examination or during the examination according to the magnetic resonance imaging apparatus10of the present modification example.

Second Modification Example

A difference between the present modification example and the embodiment is that the second image corresponds to an image in which a projected image is trimmed in accordance with a screen63.

An image processing circuitry33(or a projector control apparatus200) outputs image data (hereinafter, referred to as trimming image data) obtained after execution of a trimming process, which will be described hereinafter, to a projector100. Accordingly, projection light corresponding to the trimming image data is projected on an inner wall57of a gantry housing51and is projected as an image of a trimmed outer portion. For example, the image processing circuitry33(or the projector control apparatus200) executes trimming (hereinafter, referred to as the trimming process) with respect to a predetermined projected image in accordance with the screen63.

The trimming process is executed in accordance with the screen63. A shape of trimming in accordance with the screen63is not limited to a shape of the screen. For example, a trimming shape is set to a circle, when a shape of the screen63is an ellipse and the trimming into an elliptical shape gives an uncomfortable feeling to a patient P.

Incidentally, the trimming process is not limited to be executed in accordance with the shape of the screen63. The trimming process may be executed in accordance with an outer shape of each silhouette of various characters (mascots, animation or the like). In addition, trimming that evokes a visual stimulus with respect to the patient P during imaging may be executed in the trimming process.

Examples of the visual stimulus include trimming that evokes (calculation (mental arithmetic or calculating formula) with respect to the patient P, trimming of a region of a first image corresponding to a front face of a central visual field of a right eye of the patient P and a region of a first image corresponding to a central visual field of a left eye of the patient P into different shapes, trimming for causing the patient P to concentrate on the first image, and brightness contrast, texture, motion, binocular parallax or the like of the projected image.

In addition, there is a possibility that a light source of the projector100is included in a viewing angle range of an attendant or the like who is positioned near the couch13due to leakage light. Thus, the trimming process may be performed such that data corresponding to a second region Re2of the projected image projected by the projector100is trimmed in order to prevent the light source from being included in the viewing angle range of the attendant or the like.

FIG. 20is a diagram illustrating an example of trimming of an image in accordance with the screen63. As illustrated inFIG. 20, circular trimming is executed in a region outside an outer edge portion Re1Oc of a first region Re1A hue corresponding to the second region Re2inFIG. 20has a single hue, for example as compared withFIG. 14.

FIG. 21is a diagram illustrating an example in which the projection light corresponding to a trimmed second image is projected on the inner wall57of the gantry housing51. As illustrated inFIG. 21, the projection light corresponding to the region outside the first image inFIG. 20is projected on an inner wall (Iw1and Iw2)571of the gantry housing51inFIG. 21.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to project the second image onto the inner wall57of the gantry housing51using the trimming image data which is trimmed in accordance with the screen63. It is possible to allow the patient P to clearly recognize the first image, which is visually recognized by the patient P through a reflecting plate67and the second image, which is projected on the inner wall57of the gantry housing51, by executing the trimming of the data relating to the image in accordance with the screen63. In addition, it is possible to intentionally make the first image and the second image ambiguous through the above-described trimming. Accordingly, it is possible to accentuate content, that is, a character in image content of the first image in the case of projecting a combination of the first image and the second image or the first image.

In addition, the image to be trimmed is not necessarily a shape of the screen63, and it is also possible to change the same shape as the shape of the screen63or a line to be trimmed (hereinafter, referred to as a trimming line) in the magnetic resonance imaging apparatus10according to the present modification example. At this time, the adjustment (change) of the trimming line performed by the image processing circuitry33or the like can be utilized as various methods of creating the first image using the second image projected on the inner wall57of the gantry housing51.

For example, the adjustment of the trimming line may be used in order for research on the visual stimulus with respect to the patient P or may be used for projection of a silhouette of a character in order for relaxation of the patient P. In addition, it is possible to limit a leakage light arrival range in which the second image is projected to a minimum range through the trimming process intentionally performed such that the light source is not included in the viewing angle range of the attendant, a caregiver or the like, and it is possible to mitigate a load give to vision of the attendant, the caregiver, and the like according to the magnetic resonance imaging apparatus10of the present modification example.

As above, it is possible to project the image trimmed for various purposes on both the screen63and the inner wall57of the gantry housing51, and to provide the visual environment in accordance with the patient P, the attendant, and the purpose according to the magnetic resonance imaging apparatus10of the present modification example.

Third Modification Example

A difference between the present modification example and the embodiment is that vicinity of a boundary between a first region Re1and a second region Re2is brightened in a second image to make a patient P naturally recognize a first image.

An image processing circuitry33(or a projector control apparatus200) outputs the second image obtained by changing at least one of brightness and a hue of the second image from the boundary between the first region Re1and the second region Re2or a trimming line toward an outer edge of the second region Re2to a projector100together with the first image. Accordingly, projection light corresponding to the second image is projected on an inner wall57of a gantry housing51as the image of which at least one of the brightness and the hue is changed.

To be specific, the image processing circuitry33(or the projector control apparatus200) creates data corresponding to the projected image by changing at least one of the brightness and the hue of the second image so as to enable the Savannah effect with respect to the first image, and outputs the data to the projector100. The above-described change, performed to realize the Savannah effect with respect to the first image, includes a change of the brightness and a change of the hue in the second region Re2, for example. Incidentally, the change of the hue and the change of the brightness in the second image are not limited to the following descriptions as long as it is possible to realize the Savannah effect.

The image processing circuitry33(or the projector control apparatus200) determines the brightness at the above-described boundary or the trimming line of the second image as the same level of brightness as brightness of the first image. The image processing circuitry33(or the projector control apparatus200) decreases the brightness of the second image in a stepwise manner from the above-described boundary or the trimming line toward the outer edge of the second region Re2in the second image (brightness gradation).

The image processing circuitry33(or the projector control apparatus200) determines a hue of the above-described boundary or the trimming line of the second image as a hue which represents a hue of an outer edge of the first region Re1. The image processing circuitry33(or the projector control apparatus200) changes the hue of the second image into black in a stepwise manner from the above-described boundary or the trimming line toward the outer edge of the second region Re2in the second image (hue gradation).

FIG. 22is a diagram illustrating an example of an image (the second image which realizes the Savannah effect with respect to the first image), which is visually recognized by the patient P placed on a couch top131. As illustrated inFIG. 22, the second image has each uniform gradation of the brightness and the hue from the outer edge portion of the first region Re1toward the outer edge of the second region Re2.

To be specific, when the first image illustrated inFIG. 22has green as a basic tone, the hue gradation in the second image (the second region Re2) corresponds to a stepwise change from green to black starting from the outer edge portion of the first region Re1toward the outer edge portion of the second region Re2. In addition, the brightness gradation in the second region Re2illustrated inFIG. 22corresponds to a stepwise decrease from the same level of brightness as the brightness of the first image in the vicinity of the boundary starting from the outer edge portion of the first region Re1toward the outer edge portion of the second region Re2.

To be specific, the image processing circuitry33(or the projector control apparatus200) creates the data corresponding to the projected image by changing at least one of the brightness and the hue of the second image so as to allow the patient P to recognize that he is watching the first image in a wide space, and outputs the data to the projector100. Incidentally, the invention is not limited to the following description as long as it is possible to allow the patient P to recognize that he is watching the first image in the wide space.

The image processing circuitry33(or the projector control apparatus200) determines the hue in the second region Re2based on the hue in the first region Re1. The hue in the second region Re2is a hue obtained by, for example, averaging the hue of the outer edge of the first region Re1or the hue of the first image in the first region Re1.

The image processing circuitry33(or the projector control apparatus200) changes the hue of the second image from white into the determined hue in a stepwise manner from the above-described boundary or the trimming line toward the outer edge of the second region Re2in the second image (hue gradation). At this time, a hue of a surrounding region, which surrounds the first image (the first region Re1) with a predetermined width, is set to white in the second region Re2.

The image processing circuitry33(or the projector control apparatus200) determines the brightness at the surrounding region of the second image as the same level of brightness as brightness of an outer edge portion of the first image. That is, the brightness of the surrounding region in the second image is adapted to the brightness of the outer edge portion of the first image. The image processing circuitry33(or the projector control apparatus200) decreases the brightness of the second image in a stepwise manner from the surrounding region toward the outer edge of the second region Re2in the second image (brightness gradation).

FIG. 23is a diagram illustrating an example of the image (the second image which is configured to allow the patient P to recognize that he is watching the first image in the wide space), which is visually recognized by the patient P placed on the couch top131. As illustrated inFIG. 23, the second image has each uniform gradation of the brightness and the hue from the surrounding region toward the outer edge of the second region Re2.

To be specific, when the first image illustrated inFIG. 23has green as a basic tone, the hue gradation in the second image (the second region Re2) corresponds to a stepwise change from white to green starting from the surrounding region toward the outer edge portion of the second region Re2. In addition, the brightness gradation in the second region Re2illustrated inFIG. 23corresponds to a stepwise decrease from the same level of brightness as the brightness of the first image starting from the surrounding region toward the outer edge portion of the second region Re2.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, there is a possibility that an image of a screen63is reflected by the reflecting plate67includes not only the first image but there is a possibility that an image (the second image projected on the inner wall57of the gantry housing51) on an outer side than an outer diameter RS of the screen is also reflected, and thus, it is possible to brighten the brightness of a trimming position (near the boundary) and to decrease the brightness toward the outside of the second region Re2(darken the second image).

Accordingly, the magnetic resonance imaging apparatus10according to the present modification example can provide the visual environment (the Savannah effect) to allow the patient P to concentrate more on the first image or to feel comfortable, and further, to give a sense of openness to the patient P. Further, it is possible to suitably change each gradation of the hue and the brightness in accordance with content of the first image and the visual effect, and to optimize the effects according to the present modification example.

In addition, it is possible to project the second image on the inner wall57by setting brightness of the periphery (including the inner wall57) of the reflecting plate67to the same level of brightness as the brightness of the image on the reflecting plate67according to the magnetic resonance imaging apparatus10of the present modification example. Accordingly, it is possible to reduce an excessive difference in brightness in the vicinity of a central visual field of the patient P. That is, when the inner wall57near the patient P is dark as compared to the image (mainly the first image) on the reflecting plate67, it is possible to mitigate an impression of the patient P feeling that the brightness of the image on the reflecting plate67is stronger than brightness of the periphery, and to reduce fatigue of eyes of the patient P during an examination.

In this manner, it is possible to provide the environment in which the patient P can concentrate on and visually recognize the first image the state of mitigating a sense of stagnation with respect to the bore53, and to provide the feeling of watching the image in a wide space to the patient P according to the magnetic resonance imaging apparatus10of the present modification example.

Further, a predetermined irradiator (for example, a light-emitting diode (LED)) may be provided on a back face side (upper face side of the inner wall57of the gantry housing51) of the reflecting plate67as a configuration to further improve the effects according to the present modification example. At this time, it is possible to improve the brightness around the reflecting plate67using the irradiator.

Fourth Modification Example

A difference between the present modification example and the embodiment is that a second image projected on an inner wall57of a gantry housing51is an image which is obtained by changing at least one among a hue, brightness, and a pattern depending on a position of the inner wall57along a circumferential direction.

An image processing circuitry33(or a projector control apparatus200) outputs data (hereinafter, referred to as circumferential-direction gradient data) relating to the second image, obtained by changing at least one among the hue, the brightness, and the pattern depending on the position of the inner wall57along the circumferential direction to a projector100together with data relating to a first image. Accordingly, projection light corresponding to the second image is projected on the inner wall57of the gantry housing51as the image of which at least one of the hue, the brightness, and the pattern is changed depending on the position of the inner wall57along the circumferential direction.

To be specific, the image processing circuitry33(or the projector control apparatus200) creates the circumferential-direction gradient data based on the position of the inner wall57along the circumferential direction. Projection light (hereinafter, referred to as upper projection light), which arrives at an upper part of the inner wall, for example, in the projection light emitted from the projector100based on the circumferential-direction gradient data, includes at least one among the brightness, the hue, and the pattern forming a bright image at the time of projection, projection light (hereinafter, referred to as lower projection light), which arrives at a lower part of the inner wall, includes at least one among the brightness, the hue, and the pattern forming a dark image at the time of projection, and projection light which arrives at a side portion of the inner wall between the upper part of the inner wall and the lower part of the inner wall includes at least one among the brightness, the hue, and the pattern such that the brightness of the image decreases from the upper projection light to the lower projection light at the time of projection.

FIG. 24is a diagram illustrating that the inner wall57becomes brighter from the lower part of the inner wall toward the upper part of the inner wall in a stepwise manner in the circumferential direction by the projection light arriving at the inner wall57in a perspective manner. As illustrated inFIG. 24, the second image to be projected on the inner wall57of the gantry housing51by leakage light has brightness gradation depending on the position of the inner wall57along the circumferential direction.

As illustrated inFIG. 24, a relatively bright image is projected on the upper part of the inner wall as the second image. A relatively dark image is projected on the lower part of the inner wall as the second image. In addition, an image of which brightness decreases from the upper part of the inner wall to the lower part of the inner wall is projected on the side portion of the inner wall as the second image.

FIG. 25is a diagram illustrating an example of brightness gradation according to the projection light projected according to the circumferential-direction gradient data in a cross section of a magnetic resonance imaging system1from a side face. As illustrated inFIG. 25, the bright image is projected on the upper part of the inner wall, the dark image is projected on the lower part of the inner wall, and the image reflecting the brightness gradation is projected on the side portion of the inner wall. As illustrated inFIG. 25, viewing angle ranges (Iw1and Iw2) on the upper part of the inner wall become brighter than other positions of the inner wall57by the upper projection light. InFIG. 25, LGR represents an example of the brightness gradation projected on the inner wall57of the gantry housing51.

As illustrated inFIGS. 24 and 25, each vicinity of a side face and a lower face of the patient P placed on a couch top131is darker than the vicinity of an upper face of the patient P. In other words, the vicinity of the upper face of the patient P placed on the couch top131is brighter than each vicinity of the side face and the lower face of the patient P.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to brighten the surroundings of the patient P placed on the couch top131from the lower part of the inner wall to the upper part of the inner wall in a stepwise manner. Accordingly, it is possible to provide the light environment with the brightness gradation from the lower part of the inner wall to upper part of the inner wall in the viewing angle range of the patient P placed on the couch top131.

For example, it is possible to provide the light environment in which the periphery of the patient P is in a relatively dark state and the central visual field of the patient P (the upper part of the inner wall) is in a bright state, and to realize the environment for more effective relaxation with respect to the patient P according to the magnetic resonance imaging apparatus10of the present modification example.

In addition, an impression of the patient P toward the image projected on the inner wall57of the gantry housing51is different depending on a direction of the patient P placed on the couch top131(setting environment of the patient P), but the sensitivity of vision deteriorates in a visual field (peripheral visual field) from the upper part of the inner wall57of the gantry housing51to the lower part of the inner wall57along the circumferential direction since a reflecting plate67is present substantially at the center (near a central visual field) of the viewing angle range of the patient P in relation to the patient P having a supine posture who receives frequent examinations. Thus, it is possible to provide the environment that enables relaxation of the patient P by changing at least one among the hue, the brightness, and the pattern along the circumferential direction of the inner wall57according to the magnetic resonance imaging apparatus10of the present modification example.

Fifth Modification Example

A difference between the present modification example and the embodiment is that irradiation light relating to a hue corresponding to a second image is emitted in an irradiation range including an inner wall57to which the second image is projected using an irradiator provided in a space between a side face of a couch top131and the inner wall57, provided in the inner wall which is lower than an upper face of a patient fixing tool (headrest)137, or provided in a movable carriage61.

A plurality of the irradiators are provided at the space between the side face of the couch top131and the inner wall57along a central axis (Z-axis) of a bore53. To be specific, the plurality of irradiators are provided at a predetermined interval at positions between the side face of the couch top131and the inner wall57on a rail55inFIG. 4(for example, positions551at the same level as a level of the couch top131) along the Z-axis. Incidentally, the irradiator may be arranged at a position lower than the level of the couch top131in the above-described space.

Incidentally, the plurality of irradiators may be provided, for example, on the inner wall57lower than an upper face1371of the patient fixing tool137inFIG. 8to be arrayed along the central axis of the bore53. At this time, a position of the irradiator corresponds to a position with a predetermined height from the couch top131, for example. Examples of the predetermined height include a distance from the couch top131to the shoulder of the patient P, a body thickness of the patient P, and the like.

The irradiator irradiates the inner wall57of the gantry housing51with the irradiation light under control of a system control circuitry38. The irradiator indicates, for example, a plurality of LED's (light-emitting diodes of three colors), which can create light relating to the above-described hue, and the single irradiator includes the plurality of LED's respectively corresponding to the three primary colors of light. Incidentally, the irradiator is not limited to the LED. In addition, the irradiator may have the directivity of the irradiation light such that the irradiation light does not arrive at a reflecting plate67and a screen63.

The system control circuitry38collects a position of the couch top131inside the bore53. The system control circuitry38determines a position of the screen63inside the bore53based on the collected position collected of the couch top131. The system control circuitry38determines the irradiation range of the irradiator toward the inner wall57of the gantry housing51depending on the position of the screen63. The system control circuitry38controls the irradiator such that light of a hue corresponding to a second image is emitted to the determined irradiation range.

The irradiation range is a range, for example, from the position of the screen63to a position near the chest (or abdomen) of the patient P. The position near the chest of the patient P is stored in advance in a main memory circuitry37or the like, for example, as a predetermined distance along the Z-axis from the position of the screen63or an end of the couch top131.

In addition, the system control circuitry38controls the irradiator such that the hue is realized in accordance with image content of the second image. For example, when the second image is an image of a leaf, a tree, woods, forest, or the like, the hue according to the image content is a hue representing image content such as green and yellow green or an average hue of the second image. In addition, when the second image is an image of sea, river, sky, or the like, the hue according to the image content is a hue representing image content such as blue, light blue, and indigo blue or an average hue of the second image.

Incidentally, the system control circuitry38may control the irradiator such that the hue is realized in accordance with a visual stimulus or the like in response to direction for further accentuation of image content of a first image or a purpose of research depending on the image content of the first image.

In addition, the system control circuitry38may control the irradiator so as to adjust the amount of light and the hue of the irradiation light in response to a desire of the patient P through an operator's instruction input through an input circuitry36. At this time, the system control circuitry38controls the irradiator without changing each image content of the first image and the second image.

Further, when the couch top131on which the patient P is placed moves between an end of the bore53on the couch13side and an imaging position, the system control circuitry38controls the irradiator so as to change the hue of the irradiation light with which the inner wall57of the gantry housing51is irradiated. Incidentally, the system control circuitry38may control the irradiator such that a mode of changing the hue is changed depending on a movement direction of the couch top131along the Z-axis. At this time, each mode of changing the hue using the irradiation light with which the inner wall57of the gantry housing51is irradiated is different between a case in which the couch top131on which the patient P is placed moved from the outside of the bore53to the inside of the bore53and a case in which the couch top131on which the patient P is placed moved from the inside of the bore53to the outside of the bore53.

FIG. 26is a diagram illustrating an example of a plurality of irradiators59provided on the rail55and an irradiation range IRR. As illustrated inFIG. 26, the control of turning the plurality of irradiators59ON or OFF is executed depending on the position of the screen63inside the bore53. As illustrated inFIG. 26, the irradiation light from the irradiator59is projected on the inner wall57in a viewing angle range of the patient P.

FIG. 27is a front view according to the bore53of the gantry11. As illustrated inFIG. 27, the irradiator59is provided at the position551between the side face of the couch top131and the inner wall57on the rail55or provided at a position531of the inner wall57which is lower than the upper face1371of the patient fixing tool137inFIG. 8.

In addition, the irradiator59may be provided in a region613or615of the movable carriage61inFIG. 10. When the irradiator59is provided in the region613of the movable carriage61, the irradiator59irradiates a range from, for example, a placing face of the couch top131to the vicinity of the shoulder of the patient P placed on the couch top131. In addition, the irradiator59has the directivity so as to prevent light emitted therefrom from arriving at the reflecting plate67and the screen63. In addition, when the irradiator59does not have the above-described directivity, the movable carriage61has a shielding plate (not illustrated) that shields the irradiation of the irradiator59with respect to the reflecting plate67and the screen63. At this time, the movable carriage61is equipped with a cable (not illustrated) which electrically connects the irradiator59and the system control circuitry38and is configured using a material that is not affected by a magnetic field. At this time, it is unnecessary to control the irradiation range using the system control circuitry38, and the description regarding other control with respect to the irradiator59is the same as the above-described description, and thus, will be omitted.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, the irradiator59is provided in the space between the side face of the couch top131and the inner wall57, the position531of the inner wall57lower than the upper face1371of the patient fixing tool137, or the movable carriage61, and thus, it is possible to irradiate the irradiation range IRR including the inner wall to which the second image is projected with the irradiation light having the hue corresponding to the second image or the like, which is different from a typical illumination (illumination which has neutral white or a single color and Illuminates a dark inside of the bore53) to be arranged inside the bore53(the inner wall57of the gantry housing51).

Accordingly, when the amount of light of the second image projected on the inner wall57using leakage light according to the present embodiment and the other modification examples is weak (insufficient), that is, when it is desirable to emphasize the hue of the second image since there is a limit in the amount of light of the second image using the leakage light which is watery light, or when the periphery of the patient P is brightened in response to a desire of the patient P, it is possible to emphasize the brightness of the second image and to brighten the periphery of the patient P without changing the image content of the projected image according to the magnetic resonance imaging apparatus10of the present modification example.

Further, when the couch top131on which the patient P is placed moves between an end of the bore53on the couch13side and an imaging position, it is possible to change the hue of the irradiation light with which the inner wall57is irradiated according to the magnetic resonance imaging apparatus10of the present modification example.

As above, the patient P inserted inside the bore53can acquire the feeling of being surrounded by the projection light and the irradiation light through synergy obtained by combination of the irradiation light and the leakage light according to the magnetic resonance imaging apparatus10of the present modification example. Further, it is possible to direct the periphery of the patient P who is watching the image to enable relaxation by changing the light when the couch top131moves to the imaging position.

Sixth Modification Example

A difference between the present modification example and the embodiment is that a surface of an inner wall57of a gantry housing51has a diffuse reflection function of diffusing and reflecting projection light.

The surface of the inner wall57of the gantry housing51has the diffuse reflection function to diffuse and reflect the projection light projected by a projector100. To be specific, the surface of the inner wall57is subjected to surface treatment such as coating (for example, coating to form finely uneven surface) and sand blasting used for a surface of a base material of a screen63, for example.FIG. 28is a diagram illustrating an example of the diffuse reflection function. As illustrated inFIG. 28, the surface treatment performed on the inner wall57of the gantry housing51contributes to improvement in projection efficiency of leakage light.

According to the magnetic resonance imaging apparatus10of the present modification example, it is possible to obtain effects to be described hereinafter in addition to the effects according to the present embodiment.

According to the magnetic resonance imaging apparatus10of the present modification example, the surface treatment for realization of the diffuse reflection function is executed on the surface of the inner wall57of the gantry housing51. Accordingly, the inner wall57of the gantry housing51according to the magnetic resonance imaging apparatus10of the present modification example has the improved projection efficiency of a second image, can more clearly reflect the second image, can provide a more suitable dwelling environment to the patient P arranged inside the bore53.

According to the magnetic resonance imaging apparatus of at least one embodiment described above, it is possible to improve the dwelling ability inside the bore of the gantry.

According to the medical image diagnostic apparatus of the above-described embodiment and application examples, it is possible to improve the dwelling ability inside the bore of the gantry.