Magnetic resonance imaging apparatus and fluid-enhanced image acquisition method
First Claim
Patent Images
1. A magnetic resonance imaging apparatus comprising:
- a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and
an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein;
the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and
the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and whereinthe measurement control unit performs labeling on the fluid portion by applying the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence before the longitudinal magnetization of the labeled fluid portion is recovered to null or above, and wherein;
the RF pre-pulse includes an IR pulse which excites the longitudinal magnetization at α
(90<
α
<
270)-degrees; and
the measurement sequence portion includes a transverse magnetization generating RF pulse which generates transverse magnetization by exciting the longitudinal magnetization at β
(0<
β
≦
90)-degrees.
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Accused Products
Abstract
In order to acquire an image with enhanced contrast between a fluid portion and a stationary portion without extending the imaging time even when an IR pulse is used as an RF pre-pulse, the RF pre-pulse is applied to a region upstream of an imaging region so as to excite longitudinal magnetization of the fluid portion in a negative direction, an echo signal is measured from the imaging region, and an image with enhanced contrast of the fluid portion with respect to the stationary portion is acquired on the basis of phase information of an image reconstructed by using the echo signal.
15 Citations
15 Claims
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1. A magnetic resonance imaging apparatus comprising:
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a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement control unit performs labeling on the fluid portion by applying the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence before the longitudinal magnetization of the labeled fluid portion is recovered to null or above, and wherein; the RF pre-pulse includes an IR pulse which excites the longitudinal magnetization at α
(90<
α
<
270)-degrees; andthe measurement sequence portion includes a transverse magnetization generating RF pulse which generates transverse magnetization by exciting the longitudinal magnetization at β
(0<
β
≦
90)-degrees. - View Dependent Claims (2, 3)
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4. A magnetic resonance imaging apparatus comprising:
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a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the arithmetic processing unit, on the basis of the phase image reconstructed using the echo signal measured by the measurement sequence portion, determines the weighting coefficient for each pixel in the image, thereby obtaining the fluid-enhanced image using the weighting coefficient. - View Dependent Claims (5, 6)
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7. A magnetic resonance imaging apparatus comprising:
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a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement control unit performs labeling on the fluid portion by applying the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence before the longitudinal magnetization of the labeled fluid portion is recovered to null or above, and wherein; the fluid portion has a first fluid portion and a second fluid portion having different flow directions; the RF pre-pulse portion includes a first RF pre-pulse and a second RF pre-pulse having different flip angles; the measurement control unit performs labeling on the first fluid portion by applying the first RF pre-pulse on a first region upstream of the first fluid portion, performs labeling on the second fluid portion by applying the second pre-pulse to a second region upstream of the second fluid portion, and sets the region between the first region and the second region as the imaging region; and the arithmetic processing unit obtains the fluid-enhanced image by differentiating the contrast between the first fluid portion and the second fluid portion. - View Dependent Claims (8)
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9. A magnetic resonance imaging apparatus comprising:
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a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement control unit performs labeling on the fluid portion by applying the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence before the longitudinal magnetization of the labeled fluid portion is recovered to null or above, and wherein; the RF pre-pulse is for executing 2-dimensional spatially-selective excitation; and the measurement control unit applies the RF pulse for executing 2-dimensional spatially-selective excitation on the region which intersects with at least a part of a fluid region upstream of the imaging region, for labeling at least a part of the fluid portion. - View Dependent Claims (10)
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11. A magnetic resonance imaging apparatus comprising:
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a measurement control unit configured to control measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing unit configured to obtain an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence is formed by an RF pre-pulse portion provided with an RF pre-pulse which performs labeling on the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion configured to measure an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing unit obtains a fluid-enhanced image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement control unit performs labeling on the fluid portion by applying the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence before the longitudinal magnetization of the labeled fluid portion is recovered to null or above, and wherein; the RF pre-pulse portion has a first RF pre-pulse and a second RF pre-pulse; and the measurement control unit performs labeling on the fluid portion by applying the first RF pre-pulse to a first region upstream of the fluid portion, applies the second RF pre-pulse to a second region which is adjacent to downstream of the first region, and sets at least a part of the second region as the imaging region. - View Dependent Claims (12)
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13. A fluid-enhanced image acquisition method including:
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a measurement step of controlling measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing step of obtaining an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence has an RF pre-pulse portion comprising an RF pre-pulse for labeling the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion which measures an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing step obtains an image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement step applies the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence portion before the longitudinal magnetization of the fluid portion recovers to null, and wherein; the fluid portion includes a first fluid portion and a second fluid portion having different directions; the RF pre-pulse portion has a first RF pre-pulse and a second RF pre-pulse having different flip angles; the measurement step performs labeling on the first fluid portion by applying the first RF pre-pulse on a first region upstream of the first fluid portion, performs labeling on the second fluid portion by applying the second RF pre-pulse on a second region upstream of the second fluid portion, and sets a region between the first region and the second region as the imaging region; and the arithmetic processing step obtains the fluid-enhanced image by differentiating the contrast between the first fluid portion and the second fluid portion.
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14. A fluid-enhanced image acquisition method including:
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a measurement step of controlling measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing step of obtaining an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence has an RF pre-pulse portion comprising an RF pre-pulse for labeling the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion which measures an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing step obtains an image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, and wherein the measurement step applies the RF pre-pulse to a region upstream from the imaging region, and executes the measurement sequence portion before the longitudinal magnetization of the fluid portion recovers to null, and wherein; the RF pre-pulse is an RF pulse for executing 2-dimensional spatially-selective excitation; and the measurement step applies the RF pulse for executing 2-dimensional spatially-selective excitation to a region which intersects with at least a part of the fluid portion upstream of the imaging region, for labeling at least a part of the fluid portion.
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15. A fluid-enhanced image acquisition method including:
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a measurement step of controlling measurement of an echo signal from an imaging region of an object to be examined including a fluid portion, on the basis of a predetermined pulse sequence; and an arithmetic processing step of obtaining an image with enhanced contrast between the fluid portion and a stationary portion using the echo signal, wherein; the pulse sequence has an RF pre-pulse portion comprising an RF pre-pulse for labeling the fluid portion by exciting the longitudinal magnetization of the fluid portion in a negative direction and a measurement sequence portion which measures an echo signal from the imaging region into which the labeled fluid portion is flown; and the arithmetic processing step obtains an image with enhanced contrast between the fluid portion and the stationary portion based on phase information of the image, wherein; the RF pre-pulse portion has a first RF pre-pulse and a second RF pre-pulse; and the measurement step labels the fluid portion by applying the first RF pre-pulse on a first region upstream of the fluid portion, applies the second RF pre-pulse to a second region adjacent to the side downstream of the first region, and sets at least a part of the second region as the imaging region.
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Specification