JP5497994B2 - Magnetic resonance imaging system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus that obtains an image in a subject based on a magnetic resonance signal emitted from the subject.

  In order to image the coronary artery by the magnetic resonance imaging (MRI) method, a method of capturing images under breath holding or natural breathing using a three-dimensional (3D) SSFP (steady state free precession) sequence is used. In particular, in the case of WH MRCA (whole heart MR coronary angiography) for imaging coronary artery travel of the entire heart, the spatial resolution may not be sufficient for breath holding.

  As countermeasures against this, under natural breathing, for example, the position of the diaphragm is detected based on NMR (nuclear magnetic resonance) signals to monitor the breathing level, and the image is picked up while changing the imaging position according to the breathing level. RMC (realtime motion correction) method is used.

  However, since there is a certain limit to the variable amount of the position that can be imaged with high accuracy, a fixed threshold is set for the range of movement due to respiration, and when the movement is larger than the threshold, NMR for imaging A method of pausing signal collection is used. That is, for example, the position of the diaphragm in the body axis direction is detected from a signal (hereinafter referred to as a monitor signal) obtained by performing one-dimensional Fourier transform on the NMR signal collected for the region R as shown in FIG. it can. Since the position of the diaphragm with respect to the body axis direction periodically rises and falls according to respiration, the position of the diaphragm detected periodically is plotted in time series, as shown in FIG. Can be obtained. When the peak of the monitor signal is outside the allowable range between the upper threshold USL and the lower threshold LSL as shown in FIG. 21B, no image is taken or the collected data is not used, Collect data at certain times. Furthermore, imaging is performed while changing the imaging position according to the respiratory motion.

  By doing so, a considerably high resolution 3D image can be obtained well even under natural breathing.

  However, the breathing level is not constant and gradually decreases or gradually increases, and the portion corresponding to the position of the diaphragm in the signal obtained by one-dimensional Fourier transform of the NMR signal is within an allowable range as shown in FIG. If it is out of the range, there is a possibility that the imaging time becomes long or the inspection cannot be completed in the worst case.

  For this reason, for example, as shown in FIG. 22, a method of fixing the abdomen using a band-shaped fixture, so-called abdominal band 500, is used. This abdominal band 500 provides a certain degree of respiratory movement suppression effect.

  However, even if the abdomen is fixed with the abdominal band 500, respiratory motion cannot be completely suppressed, and in the case of imaging for a long time, the respiratory level may fluctuate and the examination time may be extended. Further, if the fixing strength by the abdominal band 500 is increased in order to reduce respiratory movement, the burden on the subject increases, and when the examination is prolonged, the subject may start to move due to discomfort due to fixation. Furthermore, when the subject is large, the abdominal band 500 may not be formed.

  On the other hand, there is also a multi-breath hold method in which three-dimensional data is imaged by repeating breath holding a plurality of times instead of under natural breathing.

  In the multi breath hold method, as shown in FIG. 23 (a), data collection for one slab S1 including the entire heart is intermittently performed in synchronization with the subject repeatedly holding his / her breath. Further, there is a method of collecting data only when the monitor signal is within an allowable range by using RMC together with this multi-breath hold method. However, since it is difficult for the subject to correctly grasp his / her breathing level, the breathing level in the breathholding state varies even if the subject intends to hold his breathing evenly. For this reason, for example, in the case of combined use with RMC, as shown in FIG. 23B, the monitor signal may not fall within the allowable range even if the breath is held. In this case, data collection is not performed even though the subject holds his / her breath, which is a burden on the subject. Moreover, such improper breath-holding increases the period during which data cannot be collected, reduces the efficiency of data collection, and increases the examination time. In addition, if the imaging time becomes longer, the subject becomes tired by repeating breath holding, and the breathing level in the breath holding state is more likely to be disturbed, so that in the worst case, there is a possibility that the examination cannot be completed. In addition, in the case of the multi-breath hold method not using RMC, since data of a plurality of slabs are collected with different breath-holding positions, there is a risk that the joints between the slabs in the reconstructed image will be scattered. there were.

On the other hand, as shown in FIG. 24A, there is a multi-slab method in which a region including the entire heart is divided into a plurality of slabs S1 to S4, and data is individually collected in each of the slabs S1 to S4. It is considered. Also in this case, it is conceivable to apply a simple multi-breath hold method or a multi-breath hold method in combination with RMC. FIG. 24B shows a case where a multi-breath hold method using RMC is applied, and the allowable range is changed for each slab. In this case, since each slab has a different allowable range, there is a problem in that a fault can be generated for each slab when the data is reconstructed as it is. In the case of the simple multi breath hold method, a similar fault occurs. Even when such a multi-slab method is adopted, in the case of the multi-breath hold method combined with RMC, the reduction in the efficiency of data collection due to different breath-holding positions occurs in the same manner as described above. In the case of, the blurring of each slab due to the difference in the breath-holding position occurs each time as described above.
JP 2000-04-1970 JP 2000-157507 A JP 2004-057226 A

  As described above, in the natural breathing method, the data collection efficiency by the navigator echo method is deteriorated due to variations in the breathing level and long-term fluctuations in the breathing level.

  In addition, when the multi breath hold method and the single slab method are applied in combination, blurring occurs due to different breath holding positions each time.

  When the combination of the multi breath hold method and the multi slab method is applied, the breath holding position is different for each data collection for one imaging region, but the collected data is different because the allowable range is changed accordingly. It becomes the data at the position. For this reason, there is a problem that misregistration occurs in the finally obtained 3D image and data discontinuity occurs in the 3D image. Therefore, in order to reduce such discontinuities, it was necessary to align each slab in image processing etc., but the data position included in each slab was already different at the time of data collection. It was difficult to match.

The present invention has been made in view of such circumstances, and an object of the present invention is to appropriately support the subject so that the subject can easily adjust the respiration level to an allowable range.

A magnetic resonance imaging apparatus according to an aspect of the present invention applies a uniform static magnetic field to a subject, and applies a high-frequency magnetic field and a gradient magnetic field to the subject according to a predetermined pulse sequence, thereby magnetic resonance from the subject. A collecting means for collecting signals; an imaging means for imaging the subject based on the magnetic resonance signals collected by the collecting means; a detecting means for detecting a respiratory level of the subject; Informing means for informing the subject whether or not the respiration level is within an allowable range, and collecting the magnetic resonance signals for imaging when the detected respiration level is within the allowable range And means for controlling the acquisition means and the imaging means so as to image the subject based on the magnetic resonance signals for imaging thus collected, The exit means sets an excitation slice or excitation slab on the diaphragm existing inside the subject, and applies the phase encoding gradient magnetic field, which is one component of the gradient magnetic field, from the excitation slice or excitation slab. The collecting means is controlled so as to repeatedly collect the magnetic resonance signals for position detection by electrocardiographic synchronization , and position information of the diaphragm is acquired based on the magnetic resonance signals for position detection collected by the collection unit. The imaging means detects the respiration level based on the acquired position information, and the imaging means collects the magnetic resonance signals for imaging immediately after the detecting means collects the magnetic resonance signals for position detection. Controlling the collection means to collect signals, and the subject based on the magnetic resonance signals for imaging collected by the collection unit And to imaging, the notification means, said guide pattern for guiding so as to approach an ideal breathing pattern breathing pattern is registered in advance of the subject, the respiratory level detected by the detection unit pattern Is displayed in such a way that can be compared.

According to the magnetic resonance imaging equipment according to one aspect of the present invention, it is possible to appropriately assist that subject is aligned in the easy tolerance breathing level.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a magnetic resonance imaging apparatus (MRI apparatus) 100 according to the present embodiment. The MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil unit 2, a gradient magnetic field power source 3, a bed 4, a bed control unit 5, a transmission RF coil 6, a transmission unit 7, a reception RF coil 8, a reception unit 9, and a computer system. 10. A video transmission system 11 and a display system are provided.

  The static magnetic field magnet 1 has a hollow cylindrical shape and generates a uniform static magnetic field in an internal space. For example, a permanent magnet or a superconducting magnet is used as the static magnetic field magnet 1.

  The gradient magnetic field coil unit 2 has a hollow cylindrical shape and is disposed inside the static magnetic field magnet 1. In the gradient coil unit 2, three types of coils corresponding to the X, Y, and Z axes orthogonal to each other are combined. In the gradient magnetic field coil unit 2, the above three types of coils are individually supplied with current from the gradient magnetic field power supply 3, and generate gradient magnetic fields whose magnetic field strengths change along the X, Y, and Z axes. The Z-axis direction is, for example, the same direction as the static magnetic field. The gradient magnetic fields of the X, Y, and Z axes are arbitrarily used as, for example, a slice selection gradient magnetic field Gs, a phase encoding gradient magnetic field Ge, and a readout gradient magnetic field Gr. The slice selection gradient magnetic field Gs is used to arbitrarily determine an imaging section. The phase encoding gradient magnetic field Ge is used to change the phase of the NMR signal in accordance with the spatial position. The readout gradient magnetic field Gr is used to change the frequency of the NMR signal in accordance with the spatial position.

  The subject 200 is inserted into the cavity of the gradient coil unit 2 while being placed on the top 4 a of the bed 4. The couchtop 4a of the couch 4 is driven by the couch controller 5 and moves in the longitudinal direction and the vertical direction. Usually, the bed 4 is installed such that the longitudinal direction thereof is parallel to the central axis of the static magnetic field magnet 1.

  The transmission RF coil 6 is disposed inside the gradient coil unit 2. The transmission RF coil 6 receives a high frequency pulse from the transmission unit 7 and generates a high frequency magnetic field.

  The transmission unit 7 transmits a high-frequency pulse corresponding to the Larmor frequency to the transmission RF coil 6.

  The reception RF coil 8 is disposed inside the gradient coil unit 2. The reception RF coil 8 receives an NMR signal radiated from the subject due to the influence of the high frequency magnetic field. An output signal from the reception RF coil 8 is input to the reception unit 9.

  The receiving unit 9 generates NMR signal data based on the output signal from the receiving RF coil 8.

  The computer system 10 includes an interface unit 10a, a data collection unit 10b, a reconstruction unit 10c, a storage unit 10d, a display unit 10e, an input unit 10f, and a main control unit 10g.

  The interface unit 10a is connected to the gradient magnetic field power source 3, the bed control unit 5, the transmission unit 7, the reception RF coil 8, the reception unit 9, and the like. The interface unit 10a inputs and outputs signals exchanged between these connected units and the computer system 10.

  The data collection unit 10b collects digital signals output from the reception unit 9 via the interface unit 10a. The data collection unit 10b stores the collected digital signal, that is, NMR signal data, in the storage unit 10d.

  The reconstruction unit 10c performs post-processing, that is, reconstruction such as Fourier transform, on the NMR signal data stored in the storage unit 10d to obtain spectrum data or image data of a desired nuclear spin in the subject 200. .

  The storage unit 10d stores NMR signal data and spectrum data or image data for each patient.

  The display unit 10e displays various information such as spectrum data or image data under the control of the main control unit 10g. As the display unit 10e, a display device such as a liquid crystal display can be used.

  The input unit 10f receives various commands and information input from the operator. As the input unit 10f, a pointing device such as a mouse or a trackball, a selection device such as a mode switch, or an input device such as a keyboard can be used as appropriate. The input unit 10f accepts designation by an operator of an excitation slice or excitation slab as an imaging region such as the entire heart or a synchronization target region such as the diaphragm.

  The main control unit 10g includes a CPU, a memory, and the like (not shown), and controls the MRI apparatus 100 overall. The main control unit 10g generates a video signal indicating whether or not the respiration level is within the allowable range. This video signal is, for example, an NTSC (national television system committee) signal.

  The video transmission system 11 transmits the video signal generated by the main control unit 10g with light.

  The display system 12 displays an image based on the image signal so that the subject 200 placed in the imaging state can see the image.

  FIG. 2 is a diagram showing a detailed configuration of the video transmission system 11 and the display system 12. In addition, the same code | symbol is attached | subjected to the same part as FIG. 1, and the detailed description is abbreviate | omitted.

  The video transmission system 11 includes an electrical-optical signal converter 11a, an optical cable (optical fiber cable) 11b, and an optical-electrical signal converter 11c. The display system 12 includes an indoor display 12a and a mirror 12b.

  Reference numeral 20 in FIG. 2 denotes a gantry. The gantry 20 accommodates the static magnetic field magnet 1, the gradient magnetic field coil unit 2, and the transmission RF coil 6. The gantry 20 has a substantially cylindrical imaging space 20 a having an axial center coinciding with the cylindrical axis formed by the static magnetic field magnet 1, and the imaging space 20 a is opened to the outside of the gantry 20. Openings 20b and 20c are formed at both ends of the photographing space. The bed 4 is arranged in the vicinity of the gantry 20 on the side of the one opening 20b. Then, the bed 4 sends the top 4a from the opening 20b to the photographing space 20a. Therefore, hereinafter, the opening 20b is referred to as a bed side opening 20b, and the opening 20c is referred to as an anti-bed side opening 20c.

  The gantry 20 and the bed 4 are disposed in a shield room R1 that is magnetically shielded. The computer system 10 is arranged in an operation room R2 different from the shield room R1.

  The electro-optical signal converter 11a is arranged outside the shield room R1, here in the operation room R2. The electrical-optical signal converter 11a converts a video signal output as an electrical signal from the interface unit 10a into an optical signal.

  The optical cable 11b transmits a video signal output as an optical signal from the electrical-optical signal converter 11a to the optical-electrical signal converter 11c.

  The optical-electrical signal converter 11c is disposed in the shield room R1. The optical-electrical signal converter 11c converts the video signal transmitted as an optical signal by the optical cable 11b into an electrical signal.

  Thus, the video transmission system 11 transmits the video signal as an optical signal in the shield room R1.

  The indoor display 12a is disposed in the shield room R1. The indoor display 12a displays a video represented by a video signal output as an electrical signal from the optical-electrical signal converter 11c. The indoor display 12a is disposed on the side of the counter bed side opening 20c in such a posture that its display surface is substantially orthogonal to the axis of the imaging space 20a and faces the imaging space 20a. As the indoor display 12a, a known display device such as a liquid crystal monitor can be used. However, the indoor display 12a includes an electromagnetic shield or the like so as to prevent noise generated therein from leaking into the shield room R1.

  The mirror 12b is disposed inside the imaging space 20a. The mirror 12b is an image displayed on the indoor display 12a so that the subject 200 placed on the top 4a and sent to the imaging space 20a can visually observe the image displayed on the indoor display 12a in the same posture. Is reflected as shown in FIG.

  Next, the operation of the MRI apparatus 100 configured as described above will be described.

  The MRI apparatus 100 collects data by a multi-slab-multi-breath hold method during WH MRCA. That is, for example, as shown in FIG. 4A, a region including the entire heart is divided into a plurality of slabs S1 to S4, and data is individually collected in each of these slabs S1 to S4. As in the prior art, when the level of the monitor signal obtained by one-dimensional Fourier transform of the magnetic resonance signal obtained from the periphery of the diaphragm or the liver is within an allowable range between the upper threshold value USL and the lower threshold value LSL. Perform the above data collection.

  However, in this embodiment, as shown in FIG. 4B, the main control unit 10g sets the upper threshold USL determined based on the respiratory level of the subject 200 obtained before or simultaneously with the acquisition of the first slab S1. And lower limit threshold value LSL is applied without changing about all the slabs S1-S4. The upper threshold USL and the lower threshold LSL are set in advance by causing the subject 200 to breathe several times before scanning, for example, by statistically obtaining the mode value of the breathing level, and setting that value as a reference (center). The predetermined allowable width (for example, 5 mm) can be obtained. The setting of the upper limit threshold USL and the lower limit threshold LSL may be performed by an operator, or may be automatically performed under the control of the main control unit 10g. At this time, the NMR signal may be used for the determination of the respiration level of the subject 200, or the signal of a respiration synchronizer (such as a bellows) may be used.

  FIG. 5 is a diagram showing an example of a sequence related to collection of NMR signals.

  This imaging method is usually performed with electrocardiogram synchronization. After a certain delay time has elapsed from the R wave, MPP (motion probing pulse) is collected as an NMR signal for obtaining a monitor signal. The MPP is collected without applying the phase encoding gradient magnetic field Ge. Immediately after collecting the MPP, data for photographing is collected. In data collection for this imaging, a phase encoding gradient magnetic field Ge is applied.

  On the other hand, during execution of WH MRCA in such a form, the main control unit 10g generates an image indicating whether or not the respiratory level of the subject 200 is within an allowable range. The above video is, for example, a video as shown in FIG. 4B representing the monitor signal and the upper threshold USL and the lower threshold LSL. The main control unit 10g displays this video on the display unit 10e for the operator to confirm. The main control unit 10g gives a video signal representing the video to the electro-optical signal converter 11a via the interface unit 10a. This video signal is converted into an optical signal by the electrical-optical signal converter 11a, transmitted through the optical cable 11b, and guided into the shield room R1. The video signal is returned to an electrical signal by the optical-electrical signal converter 11c in the shield room R1, and then given to the indoor display 12a. Thus, the indoor display 12a displays the video represented by the video signal. The image displayed on the indoor display 12a is reflected by the mirror 12b and the subject 200 can be viewed.

  Thus, the subject 200 can confirm whether or not the current respiration level is within the allowable range by confirming the image reflected on the mirror 12b. The subject 200 can hold his / her breath in a state where his / her breathing level is within an allowable range.

  Thus, the MRI apparatus 100 can reliably collect data each time the subject 200 holds his / her breath, improving the efficiency of data collection. In addition, since the data collected for each breath hold is obtained in the breathing state within a certain allowable range in any of the plurality of slabs, the data is finally based on the data collected for each of the plurality of slabs. The obtained 3D image can have high image quality with little misregistration and blurring.

  Further, the MRI apparatus 100 guides the video signal generated outside the shield room R1 into the shield room R1 as an optical signal. Thereby, it is possible to prevent the noise from the outside of the shield room R1 from affecting the collection of the magnetic resonance signal.

  This embodiment can be variously modified as follows.

  (1) The video signal may be generated by shooting the video displayed on the display unit 10e with a CCD (charge-coupled device) camera or the like.

  (2) The indoor display 12a is disposed on the side of the bed side opening 20b in a posture in which the display surface is substantially orthogonal to the axis of the imaging space 20a and faces the imaging space 20a, as indicated by a broken line in FIG. May be. Alternatively, the indoor display 12a may be arranged on the bed side opening 20b side in a posture in which the display surface is substantially parallel to the axis of the imaging space 20a. When the indoor display 12a is arranged in a posture in which the display surface is substantially parallel to the axis of the imaging space 20a, the image displayed on the indoor display 12a is reflected to the mirror 12b by the mirror 12c. However, when the indoor display 12a is arranged on the side of the bed side opening 20b, the direction of the mirror 12b is changed as shown by a broken line in FIG. The direction of the mirror 12b may be fixed or variable.

  (3) Instead of the indoor display 12a, a large display (liquid crystal, plasma, etc.) 12d may be used as shown in FIG.

  (4) Instead of the indoor display 12a, a projector 12e may be used as shown in FIG. 7 to project the video represented by the video signal onto the wall of the shield room R1. When the projector 12e is used, the image may be directly projected on the mirror 12b, or the mirror 12b may be omitted, and the image may be projected on the wall surface of the gantry 20 around the photographing space 20a. Instead of the indoor display 12a and the mirror 12b, an image may be drawn on the wall surface of the gantry 20 using a drawing device that combines a laser light emitting device and a movable mirror.

  (5) The indoor display 12a may be arranged inside the photographing space 20a. In this case, the mirror 12b may be omitted, and the subject 200 may be made to directly view the image displayed on the indoor display 12a. In this case, a liquid crystal sheet, organic EL (electroluminescence), or the like may be attached to the wall surface of the gantry 20 around the imaging space 20a.

  (6) An image generated outside the shield room R1 may be guided into the shield room R1 so that the subject 200 visually observes it.

  For example, as shown in FIG. 8, the video transmission system 11 includes an LED (light emitted diode) array 11d and an optical cable group (optical fiber group) 11e, and the display system 12 includes a visualization unit 12f.

  The LED array 11d is formed by arranging a large number of LEDs in a one-dimensional or two-dimensional manner, and reproduces a video represented by the video signal. The optical cable group 11e is formed by bundling a large number of optical cables, and transmits the video reproduced by the LED array 11d as it is. The visualization unit 12f is transmitted by the optical cable group 11e and causes the subject to visually observe the video.

  FIG. 9 is a diagram showing an example of a video reproduction state on the LED array 11d in which LEDs are arranged one-dimensionally. Note that one circle in FIG. 9 represents one LED. In FIG. 9, the upper limit threshold value USL and the lower limit threshold value LSL are represented by lighting the LEDs at both ends in blue and yellow, respectively, and the current monitor signal of one of the inner five LEDs is lit in red. Represents the current level. When the current level of the monitor signal is outside the allowable range, none of the inner five LEDs is lit.

  FIG. 10 is a diagram showing an example of a video playback state on the LED array 11d in which LEDs are two-dimensionally arranged. Note that one circle in FIG. 10 represents one LED. In FIG. 10, four LED rows arranged as shown in FIG. 9 are arranged. The change in the level of the monitor signal is expressed in the same manner as described above for each of the four LED rows.

  The visualization unit 12f may be configured to visualize an image based on the arrangement of light emitted from these optical cables by arranging the end faces of many optical cables included in the optical cable group 11e in a one-dimensional or two-dimensional manner. it can.

  FIG. 11 is a diagram illustrating an example of the configuration of the optical cable group 11e whose end portion functions as the visualization unit 12f.

  Alternatively, the visualization unit 12f may be configured to project an image on the wall surface of the gantry 20 arranged in the imaging space 20a as shown in FIG. 12 and above the imaging space 20a.

  Alternatively, a fiberscope 11f as shown in FIG. 13 may be used in place of the optical cable group 11e, and an image reproduced by the LED array 11d may be guided to the eyes of the subject 200.

  As the visualization unit 12f, a translucent optical cable array as shown in FIG. 14 may be used, and this may be attached to the wall surface of the gantry 20 above the imaging space 20a as shown in FIG.

  The translucent optical cable array as the visualization unit 12f may be arranged so that the arrangement direction of the translucent optical cables is aligned with the circumferential direction of the wall surface of the gantry around the imaging space 20a as shown in FIG.

  As shown in FIG. 17, the visualization unit 12f may be configured like glasses in which the end of the optical cable group 11e is arranged in the lens portion, and this may be attached to the face of the subject 200.

  (7) Using the video transmission technique shown in the above (6), the video displayed on the display unit 10e and the video displayed on the indoor display 12a are guided to the imaging space 20a and viewed by the subject 200. Anyway.

In this case, as shown in FIG. 18, the input end of the optical cable group 11e is connected to the display unit 10e or the indoor display 12a so that the video information displayed on the display unit 10e or the indoor display 12a can be incident without loss. Make sure they are in close contact. At this time, it is also useful to use a lens or an auxiliary light guide medium. As the visualization unit 12f, glass with a lens, diffusion glass, or the like is suitable.

  When the fiberscope 11f is used in place of the optical cable group 11e, as shown in FIG. 19, the image displayed on the display unit 10e or the indoor display 12a is reduced by the reduction lens 11g and incident on the fiberscope 11f. The image emitted from 11f is enlarged by the magnifying lens 11h and is incident on the visualization unit 12f.

  (8) The indoor display 12a may be configured like glasses with the LED array 12g built in the lens portion as shown in FIG. 20, and this may be attached to the face of the subject 200.

  (9) Several respiratory patterns may be registered in advance as an ideal state, and one of them may be used as a guide pattern to display an image that can be compared with the measured actual respiratory pattern. This makes it possible to guide the subject 200 so that the breathing pattern of the subject 200 approaches the ideal pattern. That is, the so-called external guidance method can be appropriately executed. Note that the guide pattern and the measurement pattern may be displayed in different colors. Alternatively, the HR (heart rate) at the time of resting of the subject 200 may be measured in advance, and referring to this, a breathing pattern that can finish data collection stably and quickly may be selected as a guide pattern.

  (10) A video other than the multi-slab-multi-breath hold method can be used to display the video indicating whether the respiration level is within the permissible range, as long as the data is collected when the respiration level is within the permissible range. That is, for example, the present invention is effective even when applied to a natural breathing method or a single slab-multi breath hold method.

  (11) A motion correction method for tracking the imaging region of the heart while tracking the movement of the diaphragm may be used in combination. In this way, it is possible to adjust the position of the multi-slab with high accuracy by correcting the fluctuation of the respiration level within the allowable range by the motion correction method, so that misregistration and blurring in the 3D image are further reduced. It becomes possible.

  (12) The video transmission system 11 and the display system 12 can be used to notify the subject 200 of various information other than whether or not the respiration level is within an allowable range.

  (13) The video transmission system 11 may guide the video signal into the shield room R1 as an electrical signal.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment.

1 is a diagram showing a configuration of a magnetic resonance imaging apparatus (MRI apparatus) 100 according to an embodiment of the present invention. The figure which shows the detailed structure of the video transmission system 11 and the display system 12 in FIG. The figure which shows the function of the mirror 12b in FIG. The figure which shows the data collection method in the MRI apparatus 100 shown in FIG. The figure which shows an example of the sequence which concerns on collection of a NMR signal. The figure which shows the modification structural example of the display system 12 in FIG. The figure which shows the modification structural example of the display system 12 in FIG. The figure which shows the modification structural example of the video transmission system 11 and the display system 12 in FIG. The figure which shows an example of the reproduction | regeneration state of the image | video by the LED array 11d in FIG. 2 which arranges LED in one dimension. The figure which shows an example of the reproduction | regeneration state of the image | video in the LED array 11d in FIG. 2 which arranges LED two-dimensionally. The figure which shows an example of a structure of the optical cable group 11e in which an edge part functions as the visualization part 12f in FIG. The figure which shows the specific structural example of the visualization part 12f in FIG. The figure which shows the fiberscope 11f which can be used instead of the optical cable group 11e in FIG. The figure which shows the specific structural example of the visualization part 12f in FIG. The figure which shows the example of arrangement | positioning of the visualization part 12f shown in FIG. The figure which shows the example of arrangement | positioning in the case of using a translucent optical cable array as the visualization part 12f in FIG. The figure which shows the modification structural example of the visualization part 12f. The figure which shows the modification structural example of the video transmission system 11 and the display system 12 in FIG. The figure which shows the modification structural example of the video transmission system 11 and the display system 12 in FIG. The figure which shows the modification structural example of the indoor display 12a in FIG. The figure explaining a prior art. The figure explaining a prior art. The figure explaining a prior art. The figure explaining a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Static magnetic field magnet, 2 ... Gradient magnetic field coil, 3 ... Gradient magnetic field power supply, 4 ... Bed, 4a ... Top plate, 5 ... Bed control part, 6 ... Transmission RF coil, 7 ... Transmission part, 8 ... Reception RF coil, DESCRIPTION OF SYMBOLS 9 ... Reception part, 10 ... Computer system, 10a ... Interface part, 10b ... Data collection part, 10c ... Reconstruction part, 10d ... Storage part, 10e ... Display part, 10f ... Input part, 10g ... Main control part, 11 ... Image transmission system, 11a ... optical signal converter, 11b ... optical cable, 11c ... electrical signal converter, 11d ... LED array, 11e ... optical cable group, 11f ... fiberscope, 11g ... reduction lens, 11h ... magnifying lens, 12 ... display System, 12a ... Indoor display, 12b, 12c ... Mirror, 12d ... Large display, 12e ... Projector, 12f ... Visualization unit, 12g ... LED array , 20 ... gantry, 20a ... imaging space, 20b ... bed-side opening, 20c ... anti bed-side opening, 100 ... magnetic resonance imaging apparatus (MRI apparatus), 200 ... subject.

Claims (2)

A collecting means for applying a uniform static magnetic field to the subject and applying a high-frequency magnetic field and a gradient magnetic field to the subject according to a predetermined pulse sequence to collect magnetic resonance signals from the subject;
Imaging means for imaging the subject based on the magnetic resonance signals collected by the collecting means;
Detecting means for detecting a respiration level of the subject;
Informing means for informing the subject whether or not the detected respiratory level is within an allowable range;
When the detected respiratory level is within the allowable range, the magnetic resonance signal for imaging is collected, and the subject is detected based on the magnetic resonance signal for imaging thus collected. And means for controlling said collecting means and said imaging means to image,
The detection means includes
Set an excitation slice or excitation slab on the diaphragm present inside the subject,
The collection means is controlled to repeatedly collect the magnetic resonance signal for position detection from the excitation slice or the excitation slab by electrocardiographic synchronization without applying a phase encoding gradient magnetic field that is one component of the gradient magnetic field. And
Obtaining the position information of the diaphragm based on the magnetic resonance signal for position detection collected by the collection unit;
The respiratory level is detected based on the acquired position information,
The imaging means includes
Controlling the collection means to collect the magnetic resonance signal for imaging immediately after the detection means collects the magnetic resonance signal for position detection;
The subject is imaged based on the magnetic resonance signals for imaging collected by the collection unit;
The informing means is a video that can be compared with a guide pattern for guiding the breathing pattern of the subject so as to approach a pre-registered ideal breathing pattern and a breathing level pattern detected by the detecting means. A magnetic resonance imaging apparatus. A collecting means for applying a uniform static magnetic field to the subject and applying a high-frequency magnetic field and a gradient magnetic field to the subject according to a predetermined pulse sequence to collect magnetic resonance signals from the subject;
Imaging means for imaging the subject based on the magnetic resonance signals collected by the collecting means;
Detecting means for detecting a respiration level of the subject;
Informing means for informing the subject whether or not the detected respiratory level is within an allowable range;
When the detected respiratory level is within the allowable range, the magnetic resonance signal for imaging is collected, and the subject is detected based on the magnetic resonance signal for imaging thus collected. And means for controlling said collecting means and said imaging means to image,
The detection means includes
Set an excitation slice or excitation slab at the target site present inside the subject,
The collection means is controlled to repeatedly collect the magnetic resonance signal for position detection from the excitation slice or the excitation slab by electrocardiographic synchronization without applying a phase encoding gradient magnetic field that is one component of the gradient magnetic field. And
Based on the magnetic resonance signal for position detection collected by the collection unit to obtain the position information of the target site,
The respiratory level is detected based on the acquired position information,
The imaging means includes
Controlling the collection means to collect the magnetic resonance signal for imaging immediately after the detection means collects the magnetic resonance signal for position detection;
The subject is imaged based on the magnetic resonance signals for imaging collected by the collection unit;
The informing means is a video that can be compared with a guide pattern for guiding the breathing pattern of the subject so as to approach a pre-registered ideal breathing pattern and a breathing level pattern detected by the detecting means. A magnetic resonance imaging apparatus.

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