WO2006038371A1 - Dispositif d’imagerie à résonance magnétique - Google Patents

Dispositif d’imagerie à résonance magnétique Download PDF

Info

Publication number
WO2006038371A1
WO2006038371A1 PCT/JP2005/014202 JP2005014202W WO2006038371A1 WO 2006038371 A1 WO2006038371 A1 WO 2006038371A1 JP 2005014202 W JP2005014202 W JP 2005014202W WO 2006038371 A1 WO2006038371 A1 WO 2006038371A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic resonance
magnetic field
imaging apparatus
image
resonance imaging
Prior art date
Application number
PCT/JP2005/014202
Other languages
English (en)
Japanese (ja)
Inventor
Shinji Kurokawa
Yo Taniguchi
Hisaaki Ochi
Original Assignee
Hitachi Medical Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Medical Corporation filed Critical Hitachi Medical Corporation
Priority to JP2006539172A priority Critical patent/JP4810432B2/ja
Publication of WO2006038371A1 publication Critical patent/WO2006038371A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01R33/561—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution by reduction of the scanning time, i.e. fast acquiring systems, e.g. using echo-planar pulse sequences
    • G01R33/5611—Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by Fourier encoding of the overlaps using the temporal dimension [UNFOLD], k-t-broad-use linear acquisition speed-up technique [k-t-BLAST], k-t-SENSE
    • 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

Definitions

  • the present invention relates to an inspection apparatus (MRI: Magnetic Resonance Imaging) using nuclear magnetic resonance, and more particularly, to a magnetic resonance imaging technique using coil sensitivity.
  • MRI Magnetic Resonance Imaging
  • a magnetic resonance imaging apparatus is a medical diagnostic imaging apparatus that causes nuclear magnetic resonance to occur in a hydrogen nucleus in an arbitrary cross section that crosses an examination target, and obtains a tomographic image in the cross section from the generated nuclear magnetic resonance signal. .
  • Non-Patent Document 1 In contrast to the normal imaging method, which uses only a gradient magnetic field to add position information in the phase encoding direction to an image, the imaging method of Non-Patent Document 1 uses the sensitivity distribution of the receiving coil in combination. The information is encoded into the image.
  • this encoding method is referred to as a coil sensitivity combined encoding, and encoding using only a normal gradient magnetic field that does not use sensitivity distribution is referred to as gradient magnetic field encoding.
  • the coil sensitivity combined encoding described above can be performed without phase encoding.
  • the number of phase encodes can be performed without phase encoding.
  • phase encoding is called coil sensitivity encoding.
  • the coil sensitivity encoding can be used not only in the phase encoding direction but also in the frequency encoding direction (reading direction) (see, for example, Patent Document 1). That is, by measuring a nuclear magnetic resonance signal using a coil having a frequency encoding number or more, it is not necessary to perform frequency encoding, and therefore it is not necessary to apply a gradient magnetic field for reading. When the gradient magnetic field for reading is not applied, there is an advantage that no noise is generated by switching the gradient magnetic field.
  • Patent Document 1 Japanese Patent Laid-Open No. 08-322814
  • Non-Patent Literature l Pruessmann KP, Weiger M, Scheidegger MB, Boesiger P.
  • SENSE sensitivity encoding for fast MRI. Magn Reson Med, vol. 42, no. 5, 952-62, 1999
  • Non-Patent Document 1 or Patent Document 1 described above can be performed to obtain an unfolded image.
  • noise that cannot be ignored in actual shooting, and in order to obtain a stable solution even in the presence of noise, the first-order independence between the sensitivity distributions of each subcoil must be high.
  • an object of the present invention is to provide a magnetic resonance imaging apparatus that can stably perform reconstruction using the sensitivity distribution of the coil even when the primary independence of the sensitivity distribution is low.
  • the magnetic resonance imaging apparatus of the present invention has the following characteristics.
  • High-frequency magnetic field generating means for generating a high-frequency magnetic field to be applied to an inspection object placed in a static magnetic field space, gradient magnetic field generating means for generating a gradient magnetic field to be applied to the inspection object, and the inspection object
  • Receiving means for receiving a nuclear magnetic resonance signal generated from the image, an image reconstruction means for reconstructing the image to be inspected based on the received nuclear magnetic resonance signal, and operations of the respective means.
  • a sequence control means for controlling the tomography of the examination object by nuclear magnetic resonance.
  • the receiving means has a spatially different sensitivity distribution state with respect to the examination object.
  • the nuclear magnetic resonance signal uses the sensitivity distribution obtained in advance and the S / N ratio of the nuclear magnetic resonance signal under the constraint on the magnetic moment in the inspection object, An arithmetic processing for obtaining a magnetic moment distribution of a region of interest in the inspection object is performed.
  • the receiving means includes a receiving coil configured by a plurality of sub-coil members that receive the nuclear magnetic resonance signals with spatially different sensitivity distributions. It is characterized by comprising.
  • the inspection object is mounted and in a desired direction (for example, in the body axis direction of the inspection object or in a direction substantially perpendicular to the body axis direction) And b) a movable top plate, wherein the pulse sequence control means controls the receiving means so as to receive the magnetic resonance signal a plurality of times during the movement of the top board.
  • the image reconstruction unit performs processing for maximizing an SN ratio of the reconstructed image with respect to the region of interest and an external region of the region of interest
  • the constraint condition includes a condition that the distribution of the magnetic moment in the outer region is known, and a condition that an upper limit value and a lower limit value that can be taken by the distribution of the magnetic moment in the region of interest are known.
  • a resolution lower than the resolution of an image finally obtained by imaging using the gradient magnetic field (for example, less than half the resolution of the finally obtained image)
  • the sensitivity distribution and the upper limit value and the lower limit value in the constraint conditions are determined based on the magnetic moment distribution of the inspection object obtained in advance at a resolution of (5).
  • the magnetic resonance imaging apparatus includes a display means for displaying the reconstructed image.
  • the reconstruction using the sensitivity distribution of the receiving coil can be performed even when the primary independence of the sensitivity distribution of the receiving coil is low.
  • a magnetic resonance imaging apparatus capable of performing stably can be realized.
  • a first embodiment of the magnetic resonance imaging apparatus according to the present invention will be described below.
  • FIG. 13 is a schematic view of a magnetic resonance imaging apparatus
  • FIG. 1 is a block diagram showing a schematic configuration of the nuclear magnetic resonance imaging apparatus.
  • 101 is a magnet that generates a static magnetic field
  • 103 is an inspection object
  • 300 is a top plate.
  • 101 is a magnet that generates a static magnetic field
  • 102 is a coil that generates a gradient magnetic field
  • 103 is an inspection object
  • the inspection object 103 is installed in a static magnetic field space generated by the magnet 101.
  • the sequencer 104 sends commands to the gradient magnetic field power source 105 and the high-frequency magnetic field generator 106 to generate a gradient magnetic field and a high-frequency magnetic field, respectively.
  • the high frequency magnetic field is applied to the inspection object 103 through the irradiation coil 107.
  • a signal generated from the inspection object 103 is received by the receiving coil 116 and detected by the receiver 108.
  • the sequencer 104 sets a nuclear magnetic resonance frequency (hereinafter referred to as a detection reference frequency) as a reference for detection.
  • the detected signal is sent to the computer 109, where signal processing such as image reconstruction is performed.
  • the shim coil 112 is used.
  • the shim coil 112 includes a plurality of channels, and current is supplied from the shim power supply 113.
  • the sequencer 104 controls the current flowing through each shim coil during static magnetic field uniformity adjustment.
  • the sequencer 104 sends a command to the shim power supply 113 to generate an additional magnetic field from the shim coil 112 so as to correct the static magnetic field inhomogeneity.
  • sequencer 104 normally performs control so that each device operates at a preprogrammed timing and intensity.
  • those that describe the timing and intensity of the high-frequency magnetic field, gradient magnetic field, and signal reception are called pulse sequences.
  • FIG. 14 shows the flow of photographing according to the present invention using this apparatus.
  • the shooting is performed for the main shooting by switching the coil sensitivity and the preliminary shooting at a low resolution using a normal gradient magnetic field.
  • Preliminary shooting can be performed in a short time because of its low resolution (Step 1), and the sensitivity distribution of each coil is acquired by preliminary shooting (Step 2).
  • Step 1 From the same preliminary shooting Determine the existence range to be inspected and the upper and lower limits of the pixel value of each pixel in the reconstructed image (step 3).
  • shooting is performed while switching the coil (step 4).
  • the image to be inspected is reconstructed by optimization from the data obtained in the main imaging, the sensitivity distribution obtained in the preliminary imaging, and the conditions of the inspection object (Step 5).
  • RF represents an excitation radio frequency pulse
  • Gs represents a slice selective gradient magnetic field
  • Ge represents a phase encoding gradient magnetic field.
  • the excitation high-frequency pulse 1 is applied simultaneously with the slice gradient magnetic field 2 to the inspection object, and only a desired slice is excited.
  • FIG. 3 shows an example of a specific configuration of the receiving coil.
  • the receiving coil is composed of a plurality of sub-coils 80.
  • FIG. 3 shows an example of a receiving coil composed of six sub-coils (cl to c6).
  • a diode 81 is connected to each subcoil, and each diode can be individually turned ON / OFF by a signal from the sequencer 104.
  • imaging using a gradient magnetic field generally performed in a magnetic resonance imaging apparatus is performed at a low resolution (for example, before imaging with the pulse sequence shown in FIG. 2).
  • Half of the resolution of the finally obtained image is created with the resolution of the finally obtained image by interpolation (for example, polynomial approximation).
  • FIG. 4 (a) The relationship between the sensitivity distribution of each sub-coil obtained as described above and the inspection object is as shown in FIG.
  • the sensitivity of the coil also extends outside the region of interest 900.
  • the area where the coil sensitivity exists is divided into N sections.
  • the magnitude of the magnetic moment of the hydrogen nucleus in the jth section is I. I is a value corresponding to the luminance information in the reconstructed image.
  • the nuclear magnetic resonance signal S observed through the i-th subcoil is expressed by the following (Equation 1).
  • f is a matrix whose element is sensitivity f
  • s is a vector whose element is a nuclear magnetic resonance signal S
  • the magnitude of the magnetic moment (reconstructed) I represents a vector with I as the element).
  • correct I is obtained by the following solution. That is, magnetic
  • Ij j E region of interest
  • MMSE Minimum Mean Square Error
  • e ′ is an objective function, which is an expected value of the square of the difference between the true value I of the magnitude of the magnetic moment and the estimated solution I ′.
  • ⁇ ⁇ is the expected value, and
  • ⁇ II is the size of the vector.
  • the second constraint is “I ⁇ Ij ⁇ I; region of interest”.
  • Equation 4 ⁇ is the square of the reciprocal of the SN ratio of the nuclear magnetic resonance signal, and the second term ⁇
  • lf is a term related to noise.
  • the second term is a term that maximizes the S / N ratio.
  • Equation 4 Although the solution of (Equation 4) is uniquely determined, there are various methods such as a method based on the Jacobi method and a gradient projection method as specific methods for optimization. For convergence speed and stability Which method is selected depends on how reliable the computer performance and solution are required.
  • the Jacobi method is used as a basic example.
  • Figure 5 shows a method for checking the range of the constraint condition at each iteration and replacing the value with the boundary value of the constraint condition if the range is exceeded.
  • the gradient vector d el d I 'of the objective function e at the set value is obtained (step 2).
  • (Calculated gradient vector) Change only X (1/2) (Step 3). If the result of the change does not satisfy the restriction condition, change to further satisfy the constraint condition and minimize the amount of change (step 4).
  • Step 6 If not satisfied, go back to Step 2, and if it is satisfied, let I ′ at that time be the solution. By the above procedure, is determined, and a projected image in the X-axis direction is obtained.
  • Figure 6 shows this storage state. Each is arranged and stored along the X-axis direction at a position on the ky axis in the figure corresponding to the phase encoding gradient magnetic field applied when acquiring the nuclear magnetic resonance signal.
  • the position information in the X-axis direction is given without particularly applying the read-out gradient magnetic field, and the image force S is obtained. IJ is halfway to be done.
  • FIG. 7 is an image to be obtained by photographing the inspection object, and shows the shape of the inspection object. The However, even outside the region of interest that cannot be obtained with the reconstructed image, it can be displayed.
  • the upper diagram shows a two-dimensional image to be inspected
  • the lower diagram shows a one-dimensional profile obtained by projecting the image on the X axis.
  • the X-axis and y-axis in the figure are the position axes, and the scale is set so that the pixel size is 1.
  • the X-axis direction is the direction in which the sensitivity distribution changes in each subcoil, and is the direction in which coil sensitivity encoding is performed.
  • the y-axis direction is the direction in which the sensitivity distribution does not change in each sub-coil, and is the direction in which frequency encoding is performed.
  • the vertical axis of the lower profile indicates the pixel value.
  • the inspection object used is a rectangle having a slit with a width of 4 pixels.
  • the area A shown in white is an area where the inspection object exists, and there is an area where there is no inspection object (a 4-pixel slit) between them.
  • the reconstruction in the X direction was performed with 128 sections (see Fig. 4) 128.
  • the SN ratio is 100.
  • FIG. 8 shows a reconstructed image obtained by the present invention.
  • the upper diagram shows the two-dimensional reconstructed image
  • the lower diagram shows the one-dimensional profile that is projected onto the X axis.
  • the X and y axes in the figure are axes indicating the position, the scale is the same as in FIG. 7, but the range is the range of the region of interest 900 in FIG.
  • the X-axis direction is the direction in which the sensitivity distribution changes in each subcoil, and is the direction in which coil sensitivity encoding is performed.
  • the y-axis direction is a direction in which the sensitivity distribution does not change in each sub-coil, and is a direction in which frequency encoding is performed.
  • the vertical axis of the lower profile indicates the pixel value.
  • FIG. 9 is a reconstructed image according to the conventional method.
  • the upper diagram shows the two-dimensional reconstructed image
  • the lower diagram shows the one-dimensional profile that is projected onto the X axis.
  • the X-axis and y-axis in the figure are axes indicating position, and the scale is the same as in FIGS.
  • the sensitivity distribution changes in each subcoil. This is the direction in which coil sensitivity encoding is performed.
  • the y-axis direction is a direction in which the sensitivity distribution does not change in each subcoil, and is a direction in which frequency encoding is performed.
  • the vertical axis of the lower profile indicates the pixel value.
  • An image is acquired using 16 subcoils that cover the region where the inspection target exists so that the spatial resolution in the X direction is the same as the spatial resolution achieved by the method of the present invention described above.
  • the region of interest in the X-axis direction is divided into 16 pixels and image reconstruction is performed.
  • the pixel size in the X direction of the image shown in Fig. 9 is four times that of Fig. 8.
  • spatial resolution is not obtained in the X direction, and image reconstruction fails.
  • the luminance value of the image is 2000 times the original luminance value.
  • coil sensitivity encoding can be performed with resolution that was not possible with the conventional method.
  • coil sensitivity encoding can be performed instead of frequency encoding, and the gradient magnetic field can be encoded. It is possible to shoot without noise caused by switching.
  • imaging is performed by changing the sensitivity distribution by moving the top plate on which the inspection object is placed in a desired direction.
  • the top plate is
  • the force configured to be movable in the body axis direction of the inspection object
  • it may be movable in a direction substantially perpendicular to the body axis direction.
  • FIG. 10 is a diagram showing a relationship among the inspection target 103, the top plate 300, and the receiving coil 301.
  • the inspection object is placed on a movable top plate, and the receiving coil is composed of a single coil and is stationary.
  • RF is the excitation high-frequency pulse
  • Gs is the slice selective gradient magnetic field
  • Gr is the read gradient magnetic field
  • the top plate positions pl, p2, and -pL are the celestial coordinates in the coordinate system x 'with reference to the stationary receiver coil.
  • the plate position and coil sensitivity distribution show the coil sensitivity distribution in the coordinate system fixed to the top plate.
  • the excitation high-frequency pulse 1 is applied to the inspection object simultaneously with the slice gradient magnetic field 2, and only a specific slice is excited. As a result, only a specific slice generates the nuclear magnetic resonance signal 42.
  • a time after applying the excitation high-frequency pulse 1, when the ⁇ pulse 41 is applied the magnetic resonance signal once attenuated becomes large again, and begins to attenuate again after a certain time.
  • the nuclear magnetic resonance signal repeatedly increases and decreases.
  • a read gradient magnetic field 5 is applied in the y direction in FIG. 10 to give position information in the y direction.
  • the nuclear magnetic resonance signal is measured while moving the top board.
  • the magnetic resonance signals (E (ky), E (ky), E (ky), ... ⁇ are applied by the receiving coil while applying the reading gradient magnetic field in each of two ⁇ pulses.
  • E (ky)) is measured sequentially.
  • the nuclear magnetic resonance signal E (ky) is a value at a point ky in the k space of the nuclear magnetic resonance signal received at the top plate position Pi.
  • the relationship between the sensitivity distribution f of the receiving coil and the inspection target at the coordinates fixed to the top plate at the top plate position Pi is as shown in FIG.
  • the sensitivity of the coil extends outside the region of interest 900, and the region where the coil sensitivity exists is divided into N sections.
  • the magnitude of the magnetic moment of the hydrogen nucleus existing in the j-th section is I and j. I is a value corresponding to the luminance information in the reconstructed image.
  • the present invention it is possible to stably perform reconfiguration using the sensitivity distribution of the receiving coil even when the primary independence between the sensitivity distributions of the plurality of receiving coils is low.
  • encoding using the sensitivity distribution of the receiving coil can be performed without restriction of maintaining primary independence.
  • a reading gradient magnetic field is not applied, and instead, imaging using the sensitivity distribution of the receiving coil can be performed, and imaging with less noise can be performed.
  • the phase encoding direction is set to the moving direction, the force that has conventionally been unable to move the top plate continuously is used. Therefore, if the receiver coil sensitivity encoding is used instead of the phase encoding, the top plate can be moved continuously, and images without discontinuous areas can be obtained efficiently. Can be achieved.
  • reconfiguration using the sensitivity distribution of the receiving coil can be performed even when the primary independence of the sensitivity distribution of the receiving coil is low by using the condition to be satisfied by the distribution of the magnetic moment.
  • a stable magnetic resonance imaging system can be realized in the medical field! The possibility of its use is great.
  • FIG. 1 is a diagram showing a configuration example of a magnetic resonance imaging apparatus to which the present invention is applied.
  • FIG. 2 is a diagram for explaining a pulse sequence for performing imaging by switching sub-coils in the first embodiment.
  • FIG. 3 is a diagram showing a configuration example of a receiving coil including a plurality of subcoils.
  • FIG. 4 is a diagram for explaining the relationship between the sensitivity distribution of each subcoil and the inspection object.
  • FIG. 5 is a diagram for explaining an example of an optimization procedure.
  • FIG. 6 is a diagram for explaining a state in which nuclear magnetic resonance signals and image information are stored in a memory.
  • FIG. 7 is a diagram showing the inspection target.
  • FIG. 8 shows a reconstructed image according to the present invention.
  • FIG. 9 is a diagram showing a reconstructed image obtained by a conventional method.
  • FIG. 10 is a diagram for explaining the relationship among the inspection object, the top plate, and the receiving coil in the second embodiment.
  • FIG. 11 is a diagram for explaining a pulse sequence for performing imaging while moving the top board.
  • FIG. 12 is a diagram for explaining a state in which nuclear magnetic resonance signals and image information are stored in a memory.
  • FIG. 13 is a diagram showing an overview of a photographing apparatus.
  • FIG. 14 is a diagram for explaining a flow of photographing until an image to be inspected according to the present invention is acquired. Explanation of symbols
  • Shim coil 113 ⁇ Shim power supply, 116...
  • Receiving coil 300 ⁇ Top plate, 301 ⁇ Receiving coil, 302 ⁇ Direction of moving the top plate, 400 ⁇ Measurement memory, 401 ⁇ Intermediate memory, 402 ⁇ ⁇ Image memory, 403 ⁇ ⁇ ⁇ Memory, 900 ⁇ ⁇ ⁇ Interest area.

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • General Health & Medical Sciences (AREA)
  • Radiology & Medical Imaging (AREA)
  • Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Medical Informatics (AREA)
  • Animal Behavior & Ethology (AREA)
  • Veterinary Medicine (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Public Health (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • General Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)

Abstract

L'invention concerne un dispositif d’imagerie à résonance magnétique pouvant effectuer une reconfiguration stable en utilisant une distribution de sensibilité de bobine même lorsque l’indépendance primaire de la distribution de sensibilité est faible. Le dispositif d’imagerie à résonance magnétique comprend : un moyen de génération de champ magnétique haute fréquence pour générer un champ magnétique haute fréquence à appliquer à un patient placé dans un champ magnétique statique ; un moyen de génération de gradient de champ magnétique pour générer un gradient de champ magnétique à appliquer à un patient ; un moyen de réception pour recevoir le signal de résonance magnétique nucléaire généré par le patient ; un moyen de reconfiguration d’image pour reconfigurer une image du patient en fonction du signal de résonance magnétique reçu ; et un moyen de commande de séquence pour commander le fonctionnement des moyens respectifs. Le moyen de réception possède une bobine de réception pour recevoir le signal de résonance magnétique nucléaire selon les distributions de sensibilité spatialement différentes du patient au cours d’une pluralité d’instants de réception. Sous la condition restrictive de définir une plage du moment magnétique du patient, le moyen de reconfiguration d’image utilise le rapport S/B de la distribution de sensibilité et le signal de résonance magnétique calculé à l’avance pour réaliser le calcul pour acquérir la distribution du moment magnétique de la zone concernée du patient par optimisation pour maximiser le rapport S/B de l’image reconfigurée.
PCT/JP2005/014202 2004-09-30 2005-08-03 Dispositif d’imagerie à résonance magnétique WO2006038371A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006539172A JP4810432B2 (ja) 2004-09-30 2005-08-03 磁気共鳴撮影装置

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004287272 2004-09-30
JP2004-287272 2004-09-30

Publications (1)

Publication Number Publication Date
WO2006038371A1 true WO2006038371A1 (fr) 2006-04-13

Family

ID=36142456

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2005/014202 WO2006038371A1 (fr) 2004-09-30 2005-08-03 Dispositif d’imagerie à résonance magnétique

Country Status (2)

Country Link
JP (1) JP4810432B2 (fr)
WO (1) WO2006038371A1 (fr)

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KEUPP J.; ALDEFELD B.; BOERNERT P.: "Continious Moving Table SENSE Imaging", PROCEEDINGS OF THE INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE 12TH SCIENTIFIC MEETING AND EXHIBITION, May 2004 (2004-05-01), pages 324, XP002308391 *
KIDANE T.K. ET AL: "Backus-Gilbert Regularization for SENSE Imaging", PROCEEDINGS OF THE INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE 12TH SCIENTIFIC MEETING AND EXHIBITION, May 2004 (2004-05-01), pages 2410, XP002993301 *

Also Published As

Publication number Publication date
JP4810432B2 (ja) 2011-11-09
JPWO2006038371A1 (ja) 2008-05-15

Similar Documents

Publication Publication Date Title
US9396562B2 (en) MRI reconstruction with incoherent sampling and redundant haar wavelets
CN108226831B (zh) 磁共振成像方法和磁共振成像设备
JP6270709B2 (ja) 磁気共鳴生データの再構成方法および装置
KR102067010B1 (ko) 모션 정정 ｍｒ 확산 이미징을 위한 시스템
JP6133537B2 (ja) Ｍｒｉのｂ１マッピング及びｂ１シミング
US9575154B2 (en) MR imaging using a multi-point dixon technique
KR102236865B1 (ko) 자기 공명 시스템 작동 시퀀스 확립
JP3869337B2 (ja) 磁気共鳴撮影装置
KR101663365B1 (ko) 자기 공명 제어 시퀀스 결정
US20130249553A1 (en) Mr imaging using a multi-point dixon technique
US7859262B2 (en) Method and device for magnetic resonance imaging on the basis of a partially parallel acquisition (PPA)
JP2005152655A (ja) Ｍｒデータ収集中のｒｆ電力蓄積を低減する方法及び装置
JP2005152657A (ja) 送信コイルアレイを用いて望ましい励起プロフィールに一致するｒｆ励起を発生する方法及び装置
EP3191862B1 (fr) Imagerie par résonance magnétique à temps d'écho nul
US7254435B2 (en) Method and magnetic resonance apparatus for calibrating coil sensitivities
US9846216B2 (en) Magnetic resonance imaging apparatus and magnetic resonance imaging method
US20050083054A1 (en) Method and magnetic resonance imaging apparatus for compensating contrast inhomogeneities in magnetic resonance images
US20130134972A1 (en) Method and system for b1 field mapping in magnetic resonance imaging
JP2003230549A (ja) Ｍｒ画像のアーチファクト抑制のための個別仕様空間飽和パルスシーケンス
US9500733B2 (en) Method and apparatus for obtaining main magnetic field information and radio pulse related information in a magnetic resonance imaging system with different flip angles
EP3114495A1 (fr) Système propeller pour irm avec correction de mouvement, séparation eau-graisse et estimation d'informations d'inhomogénéité de champ magnétique
JP4810432B2 (ja) 磁気共鳴撮影装置
US10345404B2 (en) Magnetic resonance imaging apparatus and RF coil apparatus
JP5688267B2 (ja) 磁気共鳴イメージング装置及びケミカル画像取得方法
US10823803B2 (en) Method and apparatus for reconstructing contrast levels from magnetic resonance acquisitions

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2006539172

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase