US20130027036A9 - Magnetic resonance imaging apparatus and method - Google Patents
Magnetic resonance imaging apparatus and method Download PDFInfo
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- US20130027036A9 US20130027036A9 US13/338,416 US201113338416A US2013027036A9 US 20130027036 A9 US20130027036 A9 US 20130027036A9 US 201113338416 A US201113338416 A US 201113338416A US 2013027036 A9 US2013027036 A9 US 2013027036A9
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- 238000002595 magnetic resonance imaging Methods 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims description 20
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 claims abstract description 80
- 230000029058 respiratory gaseous exchange Effects 0.000 claims description 84
- 230000001629 suppression Effects 0.000 claims description 27
- 210000004369 blood Anatomy 0.000 description 31
- 239000008280 blood Substances 0.000 description 31
- 230000005415 magnetization Effects 0.000 description 19
- 230000000241 respiratory effect Effects 0.000 description 16
- 206010003119 arrhythmia Diseases 0.000 description 13
- 230000006793 arrhythmia Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 9
- 210000001519 tissue Anatomy 0.000 description 9
- 230000001788 irregular Effects 0.000 description 7
- 238000004088 simulation Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 4
- 210000003205 muscle Anatomy 0.000 description 3
- 210000001015 abdomen Anatomy 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000000747 cardiac effect Effects 0.000 description 2
- 230000017531 blood circulation Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000002075 inversion recovery Methods 0.000 description 1
- 210000003734 kidney Anatomy 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7271—Specific aspects of physiological measurement analysis
- A61B5/7285—Specific aspects of physiological measurement analysis for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
- G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
- G01R33/563—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution of moving material, e.g. flow contrast angiography
- G01R33/5635—Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA]
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
- G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
- G01R33/567—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution gated by physiological signals, i.e. synchronization of acquired MR data with periodical motion of an object of interest, e.g. monitoring or triggering system for cardiac or respiratory gating
- G01R33/5673—Gating or triggering based on a physiological signal other than an MR signal, e.g. ECG gating or motion monitoring using optical systems for monitoring the motion of a fiducial marker
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- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
- A61B5/113—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb occurring during breathing
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- A61B5/346—Analysis of electrocardiograms
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- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
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- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
- G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
- G01R33/5607—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution by reducing the NMR signal of a particular spin species, e.g. of a chemical species for fat suppression, or of a moving spin species for black-blood imaging
Abstract
Description
- This application claims the benefit of Japanese Patent Application No. 2010-292725 filed Dec. 28, 2010, which is hereby incorporated by reference in its entirety.
- The present invention relates to a magnetic resonance imaging apparatus that carries out a pulse sequence in synchronization with a biosignal.
- As methods for acquiring an image of a blood flow in the abdomen of a subject, respiratory gating method and heart rate gating method are known. In the respiratory gating method, a pulse sequence is carried out in synchronization with respiration signals. In the heart rate gating method, a pulse sequence is carried out in synchronization with heart rate signals. (See, e.g., Japanese Unexamined Patent Application Publication No. 2008-148806 and Japanese Unexamined Patent Application Publication No. 2010-220859.)
- In the respiratory gating method, the respiration of a subject is detected and the timing with which a pulse sequence is carried out is determined so that data can be acquired during a period for which body motion arising from respiration is small. However, if the respiration of a subject becomes irregular during scanning, data cannot be acquired during a period for which the body motion is small and the image quality may be degraded.
- In the heart rate gating method, the heart rate of a subject is detected and the timing with which a pulse sequence is carried out is determined so that data can be acquired during a desired period of cardiac phase (for example, diastole). However, if the heart rate becomes irregular because of such a cause as arrhythmia during scanning, data cannot be acquired during a desired period of cardiac phase and the image quality may be similarly degraded.
- Therefore, an image whose quality is not degraded so much even though the respiration or heart rate of a subject becomes irregular during scanning is desired.
- A magnetic resonance imaging apparatus that carries out a pulse sequence in synchronization with a biosignal is provided.
- The pulse sequence includes an RF pulse, and a data acquisition sequence for acquiring data when a wait time has passed after the RF pulse.
- The wait time takes a variable value that can be varied based on the biosignal.
- The start timing of a data acquisition sequence can be adjusted by providing the wait time with a variable value that can be varied based on a biosignal. Therefore, degradation in image quality can be reduced.
- Further advantages will be apparent from the following description of exemplary embodiments of as illustrated in the accompanying drawings.
-
FIG. 1 is a schematic diagram of a magnetic resonance imaging apparatus in a first embodiment. -
FIGS. 2A and 2B are drawings showing a case where asubject 14 is scanned. -
FIGS. 3A and 3B are drawings showing the relation between a respiration signal Resp and a pulse sequence PS. -
FIGS. 4A-4C are drawings showing the result of simulation. -
FIG. 5 is a diagram showing an MRI apparatus in a second embodiment. -
FIGS. 6A and 6B are drawings showing the relation between a heart rate signal PSD and a pulse sequence PS. -
FIG. 7 is a diagram showing an MRI apparatus in a third embodiment. -
FIGS. 8A and 8B are drawings showing the relation between a respiration signal Resp, a heart rate signal PSD, and a pulse sequence PS in the third embodiment. -
FIGS. 9A and 9B are drawings showing the relation between a respiration signal Resp, a heart rate signal PSD, and a pulse sequence PS in a fourth embodiment. - Hereafter, exemplary embodiments will be described with reference to the drawings. However, the invention is not limited to the embodiments specifically described herein.
-
FIG. 1 is a schematic diagram of a magnetic resonance imaging apparatus in the first embodiment. - The magnetic resonance imaging (“MRI”)
apparatus 100 includes amagnetic field generator 2, a table 3, a bellows 4, a receiving coil 5, and the like. - The
magnetic field generator 2 includes abore 21 in which asubject 14 is placed, asuperconducting coil 22, agradient coil 23, and a transmittingcoil 24. Thesuperconducting coil 22 applies a static magnetic field B0, thegradient coil 23 applies a gradient pulse, and thetransmitting coil 24 transmits an RF pulse. - The table 3 has a
cradle 31 for carrying thesubject 14. Thesubject 14 is carried into thebore 21 by the cradle 81. - The bellows 4 acquires respiration signals from the
subject 14. - The receiving coil 5 is installed over the chest and abdomen of the
subject 14 and receives magnetic resonance signals from thesubject 14. - The
MRI apparatus 100 further includes a sequencer 6, atransmitter 7, a gradient magneticfield power supply 8, atrigger generation unit 9, areceiver 10, acentral processing unit 11, anoperating portion 12, and adisplay 13. - Under the control of the
central processing unit 11 and the like, the sequencer 6 sends information for acquiring an image of thesubject 14 to thetransmitter 7 and the gradient magneticfield power supply 8. - The
transmitter 7 drives thetransmitting coil 24 based on information sent from the sequencer 6. - The gradient magnetic
field power supply 8 drives thegradient coil 23 based on information sent from the sequencer 6. - The
trigger generation unit 9 generates a respiration synchronization trigger based on a respiration signal from the bellows 4. - The
receiver 10 carries out various processing on a magnetic resonance signal received at the receiving coil 5 and transmits it to thecentral processing unit 11. - The
central processing unit 11 controls the operation of each part of theMRI apparatus 100 so that the various operations of theMRI apparatus 100 are performed. Examples of such operations include transmitting required information to the sequencer 6 and thedisplay 13, reconstructing an image based on a signal received from thereceiver 10, and the like. - The
operating portion 12 inputs various commands to thecentral processing unit 11 in accordance with operation by anoperator 15. Thedisplay 13 displays varied information. - An image of the
subject 14 is acquired using theMRI apparatus 100 configured as mentioned above. -
FIGS. 2A and 2B are diagrams showing a case where thesubject 14 is scanned. -
FIG. 2A is a diagram schematically showing an image acquisition region of the subject, andFIG. 2B is a diagram showing an example of a pulse sequence PS used when thesubject 14 is scanned. - In the first embodiment, a scan for representing
arterial blood 14 b in an image acquisition region R embracing thekidney 14 c is carried out utilizing the inflow effect of thearterial blood 14 b from theheart 14 a. During this scan, the pulse sequence PS is repeatedly carried out as shown inFIG. 2B . - Each pulse sequence PS includes a selective inversion pulse SIR (Selective Inversion Recovery), a fat suppression pulse PFAT, and a data acquisition sequence DAQ.
- The selective inversion pulse SIR is a pulse that inverts the longitudinal magnetization of the tissue (arterial blood, venous blood, fat, muscle, and the like) of an inverted region ESIR of the subject 14. When a wait time W (inversion time) has passed after the selective inversion pulse SIR, the data acquisition sequence DAQ for acquiring data on the image acquisition region R is carried out. Examples of the data acquisition sequence are 3D FSE (Fast Spin Echo) and FIESTA (Fast Imaging Employing Steady state Acquisition). The
heart 14 a is located outside the inverted region RSIR; therefore, the arterial blood in theheart 14 a remains with the longitudinal magnetization M=1 even though a selective inversion pulse SIR is transmitted. During the wait time W, therefore, thearterial blood 14 b with the longitudinal magnetization M=1 flows from theheart 14 a into the image acquisition region R. Therefore, an MRI image in which arterial blood is emphatically represented and background tissue (venous blood and the like) is suppressed can be obtained by carrying out the data acquisition sequence DAQ. A fat suppression pulse PFAT is transmitted immediately before the data acquisition sequence DAQ. Therefore, the fat signals from the image acquisition region R can be effectively suppressed. Examples of the fat suppression pulse PFAT are SPECIR (Spectrally Selected IR) and STIR (Short-TI IR). - In each pulse sequence PS, the wait time W has a variable value that can be varied based on a respiration signal from the subject 14. As the result of providing the wait time W with a variable value, image data in which body motion artifacts arising from respiration are sufficiently reduced can be acquired even though the respiration of the subject becomes irregular while an image of the subject is being acquired. Hereafter, description will be given to the reason for this.
-
FIGS. 3A and 3B are drawings showing the relation between a respiration signal Resp and a pulse sequence PS. -
FIG. 3A is a drawing showing a pulse sequence PS in the case of respiratory cycle Ta, andFIG. 3B is a drawing showing a pulse sequence PS in the case of respiratory cycle Tb (<Ta). - First,
FIG. 3A will be described. - The trigger generation unit 9 (Refer to
FIG. 1 ) detects a peak of the respiration signal Resp based on the signal value of the respiration signal Resp. InFIG. 3A , the peak P0 of the respiration signal Resp occurs at time t0, therefore, thetrigger generation unit 9 detects the peak P0. When thetrigger generation unit 9 detects the peak P0, it generates a first respiration synchronization trigger TGresp1 for transmitting the selective inversion pulse SIR. The first respiration synchronization trigger TGresp1 may be generated at the position of the peak P0 or may be generated temporally behind the peak P0. In the first embodiment, the first respiration synchronization trigger TGresp1 is generated temporally behind the peak P0. - When the first respiration synchronization trigger TGresp1 is generated, the selective inversion pulse SIR is transmitted in synchronization with the first respiration synchronization trigger TGresp1. The longitudinal magnetization of tissue contained in the inverted region RSIR (Refer to
FIG. 2A ) is inverted by the selective inversion pulse SIR. InFIG. 3A , venous blood is shown as the tissue whose longitudinal magnetization is inverted by the selective inversion pulse SIR. - After transmitting the selective inversion pulse SIR, the
trigger generation unit 9 generates a second respiration synchronization trigger TGresp2 for carrying out the data acquisition sequence DAQ while the body motion of the subject 14 arising from respiration is small. The second respiration synchronization trigger TGresp2 can be generated, for example, when the signal value of the respiration signal Resp is lowered to S2. The value of the signal value S2 can be represented by, for example, Expression (1) below: -
S 2 =k(S 0 −S base) (1) - where, k is a coefficient, S0 is the signal value of the peak P0 of the respiration signal Resp, and Sbase is the base line of the respiration signal Resp.
- The base line Sbase of the respiration signal Resp represents a signal value at the time when the body motion of the subject 14 arising from respiration is sufficiently small. The base line Sbase is calculated beforehand based on, for example, the respiration signal Resp before time t0. For example, Expression (1) is converted into the following expression when the base line Sbase=0:
-
S 2 =k×S 0 (2) - Therefore, the signal value S2 can be determined by k and S0. With respect to the value k, for example, k=0.1 can be taken. When k=0.1, S2=0.1×S0. Therefore, the second respiration synchronization trigger TGresp2 is generated when the signal value of the respiration signal Resp is lowered by 90% from the peak value S0. Therefore, the second respiration synchronization trigger TGresp2 can be generated when the respiration signal Resp gets sufficiently close to the base line Sbase.
- When the second respiration synchronization trigger TGresp2 is generated, the fat suppression pulse PFAT is transmitted and the data acquisition sequence DAQ is carried out. In
FIG. 3A , the time interval from the second respiration synchronization trigger TGresp2 to when the data acquisition sequence DAQ is started is indicated by symbol “ttrg”, and the time interval from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started is indicated by symbol “tfat.” - The time interval ttrg from the second respiration synchronization trigger TGresp2 to when the data acquisition sequence DAQ is started is set so that the data acquisition sequence DAQ can be carried out while body motion arising from respiration is small. A fixed value determined before the subject 14 is scanned can be taken for the time interval ttrg. However, when the respiratory cycle of the subject 14 largely fluctuates during scanning, the respiratory cycle of the subject 14 may be measured periodically (for example, at intervals of more than 10 seconds to several tens of seconds) while the subject 14 is scanned, and the value of time interval ttrg may be changed based on the latest measured respiratory cycle. The time interval tfat from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started generally has a fixed value. However, the value may be changed as required.
- The longitudinal magnetization of the venous blood in the inverted region RSIR is inverted by the selective inversion pulse SIR but it is gradually restored during the wait time W=Wa. If the respiratory cycle Ta is, for example, 4 seconds, the wait time Wa is, for example, 1.5 seconds or so. In this case, the longitudinal magnetization of venous blood has been restored to Ma at the start time is of the data acquisition sequence DAQ as indicated by the graph of longitudinal magnetization in
FIG. 3A . During the wait time Wa, meanwhile, arterial blood with the longitudinal magnetization M=1 flows from theheart 14 a located outside the inverted region RSIR (Refer toFIG. 2A ) into the image acquisition region R. In the image acquisition region R, therefore, the longitudinal magnetization of arterial blood is sufficiently larger than the longitudinal magnetization of venous blood at the start time ts of the data acquisition sequence DAQ. For this reason, an image in which arterial blood is emphasized more than venous blood can be obtained. -
FIG. 3B shows a case where the respiratory cycle of the subject 14 transitions from Ta to Tb while the subject 14 is scanned. Also inFIG. 3B , the pulse sequence PS is carried out in the same manner as inFIG. 3A and accordingly, detailed description ofFIG. 3B will be omitted. - As shown in
FIGS. 3A and 3B , in the first embodiment, the second respiration synchronization trigger TGresp2 is generated when after the selective inversion pulse SIR is transmitted, the respiration signal Resp gets close to the base line Sbase. Therefore, if the respiratory cycle of the subject 14 changes during scanning, the generation timing of the second respiration synchronization trigger TGresp2 is changed in accordance with this change. As a result, the value of the wait time W of the pulse sequence is also changed. As is apparent from the comparison ofFIG. 3A andFIG. 3B , the wait time W of the pulse sequence PS is W=Wa inFIG. 3A while the wait time W of the pulse sequence PS is changed to W=Wb inFIG. 3B . Therefore, the start timing of the data acquisition sequence DAQ can be adjusted by taking a variable value for the wait time W. This makes it possible to carry out the data acquisition sequence DAQ while the body motion of the subject 14 arising from respiration is small and obtain an image with reduced body motion artifacts. - In the first embodiment, the wait time W of the pulse sequence PS varies according to variation in the respiratory cycle of the respiration signal Resp during scanning. Therefore, the degree of restoration of the longitudinal magnetization of venous blood differs. As is apparent from the comparison of
FIG. 3A andFIG. 3B , the longitudinal magnetization of venous blood is restored substantially to M=Ma inFIG. 3A while the longitudinal magnetization of venous blood is restored only to M=Mb (<Ma) inFIG. 3B . Also with respect to the background tissues (muscle, fat, and the like) other than venous blood, similarly to venous blood, the degree of restoration of longitudinal magnetization differs according to variation in the wait time W of the pulse sequence PS. Therefore, the contrast between arterial blood and background tissue may be reduced when the wait time W of the pulse sequence PS is varied. However, since the arterial blood in the image acquisition region R when the data acquisition sequence DAQ is carried out is with longitudinal magnetization M=1, it is sufficiently larger than the longitudinal magnetization of background tissue. Therefore, it is supposed that sufficient contrast can be maintained even though the wait time W of the pulse sequence PS varies. To verify this, simulation was carried out. Hereafter, description will be given to the result of this simulation. -
FIGS. 4A-4C are drawings showing the simulation result. -
FIG. 4A is a drawing showing the contrast between arterial blood and venous blood,FIG. 4B is a drawing showing the contrast between arterial blood and muscle, andFIG. 4C is a drawing showing contrast between arterial blood and fat. - The horizontal axes of
FIGS. 4A-4C represent the wait time W of the pulse sequence PS and the vertical axes represent the time interval Tint between a pulse sequence PS and the next pulse sequence. (Refer toFIG. 2B .) - As is apparent from
FIGS. 4A-4C , when the time interval Tint is, for example, 2000 (ms), even though the wait time W fluctuates between W=1400 (ms) and 1900 (ms), the contrast is not less than 0.4 and arterial blood can be sufficiently represented. Therefore, it is guessed that variation in the wait time W of the pulse sequence PS has relatively little influence on image quality. - The pulse sequence PS includes a fat suppression pulse PFAT between the selective inversion pulse SIR and the data acquisition sequence DAQ. However, the fat suppression pulse PFAT may be removed as required or a different RF pulse may be provided in place of the fat suppression pulse PFAT. Further, a different RF pulse may be provided in addition to the fat suppression pulse PFAT.
- The pulse sequence PS shown in
FIGS. 2A and 2B includes the selective inversion pulse SIR. However, a non-selective inversion pulse may be used or an α°-RF pulse (α°≠180°) may be used in place of the selective inversion pulse SIR. - In the description of the second embodiment, a case where the heart rate gating method is used to acquire an image of a subject will be taken as an example.
-
FIG. 5 is a diagram showing anMRI apparatus 200 in the second embodiment. - The
MRI apparatus 200 in the second embodiment is different from theMRI apparatus 100 in the first embodiment in that aheart rate sensor 41 for acquiring heart rate signals from the subject 14 is provided in place of the bellows 4. Theheart rate sensor 41 is, for example, a sphygmograph sensor. The second embodiment is also different in thattrigger generation unit 9 generates a heart rate synchronization trigger based on a heart rate signal from theheart rate sensor 41. - The other configuration elements are the same as those of the
MRI apparatus 100 in the first embodiment and the description thereof will be omitted. - The
MRI apparatus 200 in the second embodiment is configured as mentioned above. Description will be given to a method for scanning the subject 14 in the second embodiment. The image acquisition region R and the pulse sequence PS in the second embodiment are as shown inFIGS. 2A and 2B similarly to the first embodiment. -
FIGS. 6A and 6B are drawings showing the relation between the heart rate signal PSD and the pulse sequence PS. -
FIG. 6A is a drawing showing a pulse sequence PS in a case where the heart rate cycle is regular andFIG. 6B is a drawing showing a pulse sequence PS in a case where the heart rate cycle becomes irregular due to arrhythmia or the like. - First,
FIG. 6A will be described. - The
trigger generation unit 9 detects a peak of the heart rate signal PSD based on the signal value of the heart rate signal PSD. When thetrigger generation unit 9 detects the peak P0, it generates a first heart rate synchronization trigger TGPSD1 for transmitting the selective inversion pulse SIR. The first heart rate synchronization trigger TGPSD1 may be generated at the position of the peak P0 or may be generated temporally behind the peak P0. In the second embodiment, the first heart rate synchronization trigger TGPSD1 is generated temporally behind the peak P0. - When the first heart rate synchronization trigger TGPSD1 is generated, the selective inversion pulse SIR is transmitted in synchronization with the first heart rate synchronization trigger TGPSD1. The longitudinal magnetization of tissue contained in the inverted region RSIR (Refer to
FIG. 2A ) is inverted by the selective inversion pulse SIR. - When the
trigger generation unit 9 detects a peak P2 of the heart rate signal PSD generated for the second time after the transmission of the selective inversion pulse SIR, when a heart rate delay time tPSD has passed after the detected peak P2, it generates a second heart rate synchronization trigger TGPSD2. The second heart rate synchronization trigger TGPSD2 is a trigger for carrying out the data acquisition sequence DAQ during diastole. - When the second heart rate synchronization trigger TGPSD2 is generated, the fat suppression pulse PFAT is transmitted and the data acquisition sequence DAQ is carried out. In
FIG. 6A , the time interval from the second heart rate synchronization trigger TGPSD2 to when the data acquisition sequence DAQ is started is indicated by symbol “ttrg”, and the time interval from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started is indicated by symbol “tfat.” - The time interval ttrg from the second heart rate synchronization trigger TGPSD2 to when the data acquisition sequence DAQ is started takes a value so set that the data acquisition sequence DAQ can be carried out during diastole. A fixed value determined before the subject 14 is scanned can be taken for the time interval ttrg. However, the heart rate cycle of the subject 14 may be measured periodically (for example, at intervals of several seconds to several tens of seconds) while the subject 14 is scanned, and the value of time interval ttrg may be changed based on the latest measured heart rate cycle. The time interval tfat from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started generally has a fixed value. However, the value may be changed as required.
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FIG. 6B shows an example in which the interval between peaks P1 and P2 of the heart rate signal PSD becomes wider than inFIG. 6A due to arrhythmia or the like while the subject 14 is scanned. Also inFIG. 6B , the pulse sequence PS is carried out in the same manner as inFIG. 6A and accordingly, detailed description ofFIG. 6B will be omitted. - In the second embodiment, a peak P2 that occurs after the transmission of the selective inversion pulse SIR is detected and a second heart rate synchronization trigger TGPSD2 is generated behind the peak P2 by a heart rate delay time tPSD. Therefore, even though the heart rate cycle of the subject 14 is instantaneously changed by arrhythmia or the like during scanning, the generation timing of the second heart rate synchronization trigger TGPSD2 is changed in accordance with this change. Therefore, the value of wait time W of the pulse sequence PS is also changed. As is apparent from the comparison of
FIG. 6A andFIG. 6B , the wait time W of the pulse sequence PS is W=Wa inFIG. 6A while the wait time W of the pulse sequence PS is changed to W=Wb inFIG. 6B . Therefore, the start timing of the data acquisition sequence DAQ can be adjusted by taking a variable value for the wait time W. This makes it possible to carry out the data acquisition sequence DAQ during diastole even though arrhythmia occurs during scanning and obtain an image with enhanced arterial blood. - Also in the second embodiment, the wait time W of the pulse sequence PS varies during scanning as in the first embodiment. However, as described with reference to the simulation result shown in
FIGS. 4A-4C , it is guessed that any variation in the wait time W of the pulse sequence PS has relatively little influence on image quality. - In the description of the third embodiment, a case where both the respiratory gating method and the heart rate gating method are used to acquire an image of a subject will be taken as an example.
-
FIG. 7 is a diagram showing anMRI apparatus 300 in the third embodiment. - The
MRI apparatus 300 in the third embodiment is different from theMRI apparatus 100 in the first embodiment in that aheart rate sensor 41 for acquiring heart rate signals from the subject 14 is provided in addition to the bellows 4. Theheart rate sensor 41 is, for example, a sphygmograph sensor. The third embodiment is also different in thattrigger generation unit 9 generates a respiration synchronization trigger based on a respiration signal from the bellows 4 and generates a heart rate synchronization trigger based on a heart rate signal from theheart rate sensor 41. - The other configuration elements are the same as those of the
MRI apparatus 100 in the first embodiment and the description thereof will be omitted. - The
MRI apparatus 300 in the third embodiment is configured as mentioned above. Description will be given to a method for scanning the subject 14 in the third embodiment. The image acquisition region R and the pulse sequence PS in the third embodiment are as shown inFIGS. 2A and 2B similarly to the first embodiment. -
FIGS. 8A and 8B are drawings showing the relation between the respiration signal Resp, the heart rate signal PSD, and the pulse sequence PS in the third embodiment. -
FIG. 8A is a drawing showing a pulse sequence PS in a case where the heart rate cycle is regular andFIG. 8B is a drawing showing a pulse sequence PS in a case where the heart rate cycle becomes irregular due to arrhythmia or the like. - First,
FIG. 8A will be described. - The
trigger generation unit 9 detects a peak of the respiration signal Resp based on the signal value of the respiration signal Resp. InFIG. 8A , the peak P0 of the respiration signal Resp occurs at time t0. Therefore, thetrigger generation unit 9 detects the peak P0. When thetrigger generation unit 9 detects the peak P0, it generates a respiration synchronization trigger TGresp for transmitting the selective inversion pulse SIR. The respiration synchronization trigger TGresp may be generated at the position of the peak P0 or may be generated temporally behind the peak P0. In the third embodiment, the respiration synchronization trigger TGresp is generated temporally behind the peak P0. - When the respiration synchronization trigger TGresp is generated, the selective inversion pulse SIR is transmitted in synchronization with the respiration synchronization trigger TGresp. The longitudinal magnetization of tissue contained in the inverted region RSIR (Refer to
FIG. 2A ) is inverted by the selective inversion pulse SIR. - When the
trigger generation unit 9 detects a peak P2 of the heart rate signal PSD generated for the second time after the transmission of the selective inversion pulse SIR, when a heart rate delay time tpSD has passed after the detected peak P2, it generates a heart rate synchronization trigger TGPSD. The heart rate synchronization trigger TGPSD is a trigger for carrying out the data acquisition sequence DAQ during diastole. - When the heart rate synchronization trigger TGPSD is generated, the fat suppression pulse PFAT is transmitted and the data acquisition sequence DAQ is carried out. In
FIG. 8A , the time interval from the heart rate synchronization trigger TGPSD to when the data acquisition sequence DAQ is started is indicated by symbol “ttrg,”, and the time interval from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started is indicated by symbol “tfat.” - The time interval ttrg from the heart rate synchronization trigger TGPSD to when the data acquisition sequence DAQ is started is set so that the data acquisition sequence DAQ can be carried out during diastole. A fixed value determined before the subject 14 is scanned can be taken for the time interval ttrg. However, the heart rate cycle of the subject 14 may be measured periodically (for example, at intervals of several seconds to several tens of seconds) while the subject 14 is scanned, and the value of time interval ttrg may be changed based on the latest measured heart rate cycle. The time interval tfat from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started generally has a fixed value; however, the value may be changed as required.
-
FIG. 8B shows an example in which the interval between peaks P1 and P2 of the heart rate signal PSD becomes wider than inFIG. 8A due to arrhythmia or the like while the subject 14 is scanned. Also inFIG. 8B , the pulse sequence PS is carried out in the same manner as inFIG. 8A and accordingly, detailed description ofFIG. 8B will be omitted. - In the third embodiment, a peak P2 that occurs after the transmission of the selective inversion pulse SIR is detected. Then the heart rate synchronization trigger TGPSD for carrying out the data acquisition sequence DAQ is generated behind the peak P2 by a heart rate delay time tPSD. Therefore, if the heart rate cycle of the subject 14 is instantaneously changed by arrhythmia or the like during scanning, the generation timing of the heart rate synchronization trigger TGPSD is changed in accordance with this change. As a result, the value of wait time W of the pulse sequence PS is also changed. As is apparent from the comparison of the
FIG. 8A andFIG. 8B , the wait time W of the pulse sequence PS is W=Wa inFIG. 8A while the wait time W of the pulse sequence PS is changed to W=Wb inFIG. 8B . Therefore, the start timing of the data acquisition sequence DAQ can be adjusted by taking a variable value for the wait time W. This makes it possible to carry out the data acquisition sequence DAQ during diastole even though arrhythmia occurs during scanning and obtain an image with enhanced arterial blood. - Also in the third embodiment, the wait time W of the pulse sequence PS varies during scanning as in the first embodiment. However, as described with reference to the simulation result in
FIGS. 4A-4C , it is guessed that it has relatively little influence on image quality. - In the description of the fourth embodiment, another case where both the respiratory gating method and the heart rate gating method are used to acquire an image of a subject will be taken as an example.
- An MRI apparatus in the fourth embodiment is different from the
MRI apparatus 300 in the third embodiment in that two respiration synchronization triggers are generated. The other configuration elements are the same as those of theMRI apparatus 300 in the third embodiment and the description thereof will be omitted. - Description will be given to a method for scanning the subject 14 in the fourth embodiment with reference to
FIGS. 9A and 9B . -
FIGS. 9A and 9B are drawings showing the relation between the respiration signal Resp, the heart rate signal PSD, and the pulse sequence PS in the fourth embodiment. -
FIG. 9A is a drawing showing a pulse sequence PS in the case of heart rate cycle Ta, andFIG. 9B is a drawing showing a pulse sequence PS in a case where the heart rate cycle changes from Ta to Tb and the heart rate cycle becomes irregular due to arrhythmia or the like. - First,
FIG. 9A will be described. - In the fourth embodiment, a first respiration synchronization trigger TGresp1 and a second respiration synchronization trigger TGresp2 are generated based on the respiration signal Resp. The first respiration synchronization trigger TGresp1 and the second respiration synchronization trigger TGresp2 are generated in the same manner as in the first embodiment.
- The
trigger generation unit 9 detects a peak P2 of the heart rate signal PSD that occurs for the first time after the generation of the second respiration synchronization trigger TGresp2. When the peak P2 of the heart rate signal PSD is detected, a heart rate synchronization trigger TGPSD is generated when a heart rate delay time tPSD has passed after the detected peak P2. The heart rate synchronization trigger TGPSD is a trigger for carrying out the data acquisition sequence DAQ during diastole. - When the heart rate synchronization trigger TGPSD is generated, the fat suppression pulse PFAT is transmitted and the data acquisition sequence DAQ is carried out. In
FIG. 9A , the time interval from the heart rate synchronization trigger TGPSD to when the data acquisition sequence DAQ is started is indicated by symbol “ttrg”, and the time interval from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started is indicated by symbol “tfat.” - The time interval ttrg from the heart rate synchronization trigger TGPSD to when the data acquisition sequence DAQ is started takes a value so set that the data acquisition sequence DAQ can be carried out during diastole. A fixed value determined before the subject 14 is scanned can be taken for the time interval ttrg. However, the heart rate cycle of the subject 14 may be measured periodically (for example, at intervals of several seconds to several tens of seconds) while the subject 14 is scanned, and the value of time interval ttrg may be changed based on the latest measured heart rate cycle. The time interval tfat from the fat suppression pulse PFAT to when the data acquisition sequence DAQ is started generally has a fixed value; however, the value may be changed as required.
-
FIG. 9B shows an example in which the respiratory cycle of the subject is changed from Ta to Tb and the interval between peaks P0 and P1 of the heart rate signal PSD becomes narrower than inFIG. 9A due to arrhythmia or the like. Also inFIG. 9B , the pulse sequence PS is carried out in the same manner as inFIG. 9A and accordingly, detailed description ofFIG. 9B will be omitted. - In the fourth embodiment, the second respiration synchronization trigger TGresp2 is generated when after the selective inversion pulse SIR is transmitted, the respiration signal Resp gets close to the base line Sbase. Therefore, if the respiratory cycle of the subject 14 changes during scanning, the generation timing of the second respiration synchronization trigger TGresp2 is changed in accordance with this change. As a result, the value of the wait time W of the pulse sequence PS is also changed. As is apparent from the comparison of
FIG. 9A andFIG. 9B , the wait time W of the pulse sequence PS is W=Wa inFIG. 9A while the wait time W of the pulse sequence PS is changed to W=Wb inFIG. 9B . Therefore, the start timing of the data acquisition sequence DAQ can be adjusted by taking a variable value for the wait time W. This makes it possible to carry out the data acquisition sequence DAQ while the body motion of the subject 14 arising from respiration is small and obtain an image with reduced body motion artifacts. - In the fourth embodiment, further, a peak P2 of the heart rate signal PSD that occurs for the first time after the generation of the second respiration synchronization trigger TGresp2 is detected, and a heart rate synchronization trigger TGPSD is generated behind this peak P2 by a heart rate delay time tPSD. Therefore, if the heart rate cycle of the subject 14 is instantaneously changed by arrhythmia or the like during scanning, the generation timing of the heart rate synchronization trigger TGPSD is changed in accordance with this change. As a result, the value of wait time W of the pulse sequence PS is changed. For this reason, the start timing of the data acquisition sequence DAQ can be adjusted by taking a variable value for the wait time W. This makes it possible to carrying the data acquisition sequence DAQ during diastole even though arrhythmia occurs during scanning and obtain an image with enhanced arterial blood.
- Also in the fourth embodiment, the wait time W of the pulse sequence PS varies during scanning as in the first embodiment. However, as described with reference to the simulation result in
FIGS. 4A-4C , it is guessed that it has relatively little influence on image quality. - Many widely different embodiments may be configured without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102015215141A1 (en) * | 2015-08-07 | 2017-02-09 | Siemens Healthcare Gmbh | Synchronization device and method for synchronizing an imaging device |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
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JP5977158B2 (en) | 2012-11-30 | 2016-08-24 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Detection apparatus, magnetic resonance apparatus, detection method, and program |
JP5965880B2 (en) * | 2013-09-30 | 2016-08-10 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic resonance apparatus and program |
DE102013226638A1 (en) * | 2013-12-19 | 2015-06-25 | Siemens Aktiengesellschaft | Method for magnetic resonance imaging |
KR101472709B1 (en) * | 2014-04-25 | 2014-12-16 | 박영근 | Health Medical Examination Method including Detailed Examination Information |
DE102014217729B4 (en) * | 2014-09-04 | 2016-03-24 | Siemens Aktiengesellschaft | Variable number of inversion pulses when acquiring magnetic resonance data in a respiration-driven target area |
CN106539584B (en) * | 2015-09-22 | 2020-08-04 | 上海联影医疗科技有限公司 | Magnetic resonance imaging method and system |
CN109714143B (en) * | 2017-10-26 | 2021-12-31 | 通用电气公司 | Synchronization system and method based on wireless or limited cable interconnection and MR system |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4777959A (en) * | 1986-09-17 | 1988-10-18 | Spacelabs, Inc. | Artifact detection based on heart rate in a method and apparatus for indirect blood pressure measurement |
US20080211497A1 (en) * | 2007-01-22 | 2008-09-04 | Yuji Iwadate | Mri apparatus |
US20080242973A1 (en) * | 2007-04-02 | 2008-10-02 | Carsten Warmuth | Heart imaging with adaptive inversion time |
US20090018433A1 (en) * | 2007-07-11 | 2009-01-15 | Kabushiki Kaisha Toshiba | Magnetic resonance imaging apparatus and magnetic resonance imaging method |
US20090245607A1 (en) * | 2008-03-31 | 2009-10-01 | Toshiba Medical Systems Corporation | Magnetic resonance imaging apparatus and scanning-condition setting method |
US20090270719A1 (en) * | 2008-04-23 | 2009-10-29 | Mitsuharu Miyoshi | Mri apparatus |
US20100045290A1 (en) * | 2008-08-25 | 2010-02-25 | Mitsuharu Miyoshi | Magnetic resonance imaging apparatus and method for controlling the same |
US20100249574A1 (en) * | 2009-03-24 | 2010-09-30 | Mitsue Miyazaki | Magnetic resonance imaging apparatus and magnetic resonance imaging method |
US20100312098A1 (en) * | 2006-09-06 | 2010-12-09 | Kabushiki Kaisha Toshiba | Magnetic resonance imaging apparatus and image processing apparatus |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5429134A (en) * | 1994-06-27 | 1995-07-04 | General Electric Company | Multi-phase fat suppressed MRI cardiac imaging |
JP2007185547A (en) * | 1998-04-20 | 2007-07-26 | Toshiba Corp | Mri system |
JP2005278919A (en) * | 2004-03-30 | 2005-10-13 | Hitachi Medical Corp | Magnetic resonance imaging apparatus |
JP4896526B2 (en) * | 2006-01-11 | 2012-03-14 | 株式会社東芝 | Magnetic resonance imaging system |
JP4956170B2 (en) | 2006-12-15 | 2012-06-20 | 株式会社日立メディコ | Magnetic resonance imaging system |
JP5022696B2 (en) * | 2006-12-22 | 2012-09-12 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic resonance imaging system |
JP2008178592A (en) | 2007-01-25 | 2008-08-07 | Ge Medical Systems Global Technology Co Llc | Magnetic resonance imaging device, scanning device, magnetic resonance imaging method, and program therefor |
JP2009056072A (en) * | 2007-08-31 | 2009-03-19 | Ge Medical Systems Global Technology Co Llc | Magnetic resonance imaging apparatus |
JP5854575B2 (en) | 2007-12-10 | 2016-02-09 | 株式会社東芝 | Magnetic resonance imaging system |
JP5383036B2 (en) | 2007-12-28 | 2014-01-08 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | MRI equipment |
JP5546735B2 (en) | 2008-02-29 | 2014-07-09 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | MRI equipment |
CN103462607B (en) * | 2008-09-04 | 2017-01-18 | 东芝医疗系统株式会社 | Magnetic resonance imaging apparatus |
JP2010131200A (en) * | 2008-12-04 | 2010-06-17 | Toshiba Corp | Mri apparatus and photography trigger signal generating unit for mri apparatus |
JP5373416B2 (en) | 2009-01-30 | 2013-12-18 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic resonance imaging apparatus and program |
JP5633896B2 (en) * | 2009-02-27 | 2014-12-03 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic resonance imaging system |
JP5558731B2 (en) | 2009-03-24 | 2014-07-23 | 株式会社東芝 | Magnetic resonance imaging system |
US8183864B2 (en) | 2009-04-15 | 2012-05-22 | Siemens Medical Solutions Usa, Inc. | System for multi nucleus cardiac MR imaging and spectroscopy |
JP2011110328A (en) * | 2009-11-30 | 2011-06-09 | Ge Medical Systems Global Technology Co Llc | Magnetic resonance imaging apparatus |
-
2010
- 2010-12-28 JP JP2010292725A patent/JP5345610B2/en active Active
-
2011
- 2011-12-28 US US13/338,416 patent/US9439603B2/en active Active
- 2011-12-28 CN CN201610034545.3A patent/CN105662414B/en active Active
- 2011-12-28 CN CN201110462061.6A patent/CN102525464B/en active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4777959A (en) * | 1986-09-17 | 1988-10-18 | Spacelabs, Inc. | Artifact detection based on heart rate in a method and apparatus for indirect blood pressure measurement |
US20100312098A1 (en) * | 2006-09-06 | 2010-12-09 | Kabushiki Kaisha Toshiba | Magnetic resonance imaging apparatus and image processing apparatus |
US20080211497A1 (en) * | 2007-01-22 | 2008-09-04 | Yuji Iwadate | Mri apparatus |
US20080242973A1 (en) * | 2007-04-02 | 2008-10-02 | Carsten Warmuth | Heart imaging with adaptive inversion time |
US20090018433A1 (en) * | 2007-07-11 | 2009-01-15 | Kabushiki Kaisha Toshiba | Magnetic resonance imaging apparatus and magnetic resonance imaging method |
US20090245607A1 (en) * | 2008-03-31 | 2009-10-01 | Toshiba Medical Systems Corporation | Magnetic resonance imaging apparatus and scanning-condition setting method |
US20090270719A1 (en) * | 2008-04-23 | 2009-10-29 | Mitsuharu Miyoshi | Mri apparatus |
US20100045290A1 (en) * | 2008-08-25 | 2010-02-25 | Mitsuharu Miyoshi | Magnetic resonance imaging apparatus and method for controlling the same |
US20100249574A1 (en) * | 2009-03-24 | 2010-09-30 | Mitsue Miyazaki | Magnetic resonance imaging apparatus and magnetic resonance imaging method |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102015215141A1 (en) * | 2015-08-07 | 2017-02-09 | Siemens Healthcare Gmbh | Synchronization device and method for synchronizing an imaging device |
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