Abstract: An MRI apparatus for imaging of a bodily fluid flowing inside a subject includes a gradient coil which applies gradient pulses to the subject, a transmission coil which transmits RF pulses to the subject, and a control part which controls the gradient coil and the transmission coil. The control part controls the gradient coil and the transmission coil in order to: saturate longitudinal magnetization of the bodily fluid in a field of saturation positioned on an upstream flow of the bodily fluid during a saturation period, invert the direction of longitudinal magnetization of the bodily fluid in an imaging field of view positioned on an downstream flow of the bodily fluid during an inversion period following the saturation period, and acquire MR signals from the bodily fluid in the imaging field of view during a data acquisition period following the inversion period.

Abstract: A magnetic resonance imaging apparatus configured to scan a subject in order to collect magnetic resonance signals from the subject in a magnetostatic field space, the magnetic resonance imaging apparatus includes a scanning unit configured to execute an imaging pulse sequence after executing a preparation pulse sequence to transmit preparation pulses.

Abstract: The present invention provides an MRI apparatus with selective saturation without affection to the integral value of gradient magnetic field in 1TR. The MRI apparatus comprises a signal acquisition device for applying static field, gradient magnetic field pulses and RF pulses to an object to acquire magnetic resonance signals therefrom, an image reconstruction device for reconstructing an image based on the magnetic resonance signals acquired, and a controller device for controlling both device. The controller device directs the signal acquisition device to apply gradient magnetic field pulses and RF pulses for selective saturation for a number of times prior to applying gradient magnetic field pulses and RF pulses for signal acquisition.

Abstract: An MR data acquisition method for acquiring data D_?fat according to a steady-state pulse sequence specifying that a phase of an RF pulse is varied in order of 0, 1×?fat, 2×?fat, etc., wherein ?fat=(2?TR/T_out+2×m)×? is established on an assumption that m denotes an integer equal to or larger than 0 and meets TR/(2×T_out)?1<m<TR/(2×T_out) where TR denotes a repetition time and T_out denotes a time during which spins in water and spins in fat are out of phase with each other due to chemical shifts.

Abstract: A magnetic resonance imaging apparatus which executes an imaging sequence for obtaining, as imaging data, magnetic resonance signals each generated from a spin excited at a subject within a static magnetic field space and produces an image about the subject, based on the imaging data obtained by the execution of the imaging sequence, includes a scan section which executes the imaging sequence and executes, before the execution of the imaging sequence, a preparation sequence for transmitting preparation pulses to the subject in such a manner that signal intensities of the magnetic resonance signals differ according to the velocities of spins moved in the subject, wherein the scan section sequentially transmits, as the preparation pulses, a first RF pulse, a second RF pulse, a third RF pulse and a fourth RF pulse respectively to the subject, wherein the scan section transmits a first crusher gradient pulse constituted of a pair of gradient pulses to the subject in such a manner that a point of time at which an

Abstract: With the objective of generating an imaging area including fluid with desired image quality at a subject and enhancing image quality, a first inversion recovery pulse is transmitted so as to invert spins in a second subject region which includes a first subject region used as the imaging area and is broader than the first subject region, before execution of a pulse sequence corresponding to an FSE method at every TR in an imaging sequence. After the execution of the pulse sequence corresponding to the FSE method, a second refocus pulse is transmitted so as to cause spins in a third subject region including the first subject region and wider than the first subject region to reconverge. A fast recovery pulse is transmitted to selectively recover spins in the first subject region. Thereafter, a second inversion recovery pulse is transmitted so as to invert the spins in the second subject region.

Abstract: An object of the present invention is to acquire data, which is used to construct a water component-enhanced/fat component-suppressed image, with a repetition time TR set to a desired value. Included are a data acquisition unit and an image construction unit. The data acquisition unit acquires data D_?fat according to a steady-state pulse sequence specifying that the phase of an RF pulse is varied in order of 0, 1×?fat, 2×?fat, etc. Herein, ?fat=(2?TR/T_out+2×m)×? is established on the assumption that m denotes an integer equal to or larger than 0 and meets TR/(2×T_out)?1<m<TR/(2×T_out) where TR denotes the repetition time and T_out denotes the time during which spins in water and spins in fat are out of phase with each other due to chemical shifts. The image construction unit constructs an MR image Gw using the data D_?fat.

Abstract: With the objective of easily drawing a flow such as a bloodstream in a subject at low luminance, there is provided a magnetic resonance imaging apparatus including a static magnetic field forming unit, a transmission unit which transmits a plurality of inversion RF pulses to a subject lying in a static magnetic field plural times within one repetition time after transmission of one excitation RF pulse thereby to excite spins of the subject, a gradient magnetic field application unit, a data acquisition unit which acquires magnetic resonance signals encoded by the gradient magnetic field, and an image generation unit which generates an image of the subject based on the magnetic resonance signals acquired by the data acquisition unit. The gradient magnetic field application unit applies velocity encode gradient pulses inverted to one another in polarity to the subject within transmission interval times for the plural RF pulses transmitted to the subject.

Abstract: An apparatus includes acquiring means for acquiring echo data of a plurality of views in which a phase difference between water and fat is 2?/m with spins within a subject brought to the SSFP state and repeating the acquisition for k=0 through M?1 with a step difference in a phase of an RF pulse of 2?·k/M; transforming means for conducting Fourier transformation on the echo data based on the phase step difference; separating means for separating water data and fat data respectively in F(0) term and F(1) term of the Fourier-transformed data using the phase difference between water and fat; adding means for obtaining a sum of absolute values of at least the water data or fat data in the F(0) term and F(1) term; and image producing means for producing an image based on the sum data.

Abstract: Versatility and the quality of images are to be improved. As preparation pulses, a first RF pulse to flip along the yz plane spins oriented in a magnetostatic field direction in a subject; a velocity encoding gradient pulse which, in spins flipped by that first RF pulse, mutually shifts the phase of spins in a static state and the phase of spins in a moving state; and a second RF pulse to flip along the yz plane spins whose phase has been shifted by the velocity encoding gradient pulse are successively transmitted. After that, a killer pulse is transmitted to extinguish the transverse magnetizations of the spins flipped by the second RF pulse.

Abstract: The present invention provides an MRI apparatus with selective saturation without affection to the integral value of gradient magnetic field in 1TR. The MRI apparatus comprises a signal acquisition device for applying static field, gradient magnetic field pulses and RF pulses to an object to acquire magnetic resonance signals therefrom, an image reconstruction device for reconstructing an image based on the magnetic resonance signals acquired, and a controller device for controlling both device. The controller device directs the signal acquisition device to apply gradient magnetic field pulses and RF pulses for selective saturation for a number of times prior to applying gradient magnetic field pulses and RF pulses for signal acquisition.

Abstract: An MRI method comprising preparing at least two pulse sequence databases (PSDs) assumed to have the same echo time (TE) and different repetition times (TR), driving a magnet system of an MRI apparatus in accordance with the two PSDs and collecting MR signals at that time, generating an MR image from MR signals collected in accordance with the PSDs, and weighting a tissue having a specific T1 value with reference to an image corresponding to a found difference between two MR images.

Abstract: An MR imaging includes acquiring echoes from the object by implementing a pulse sequence which specifies the conditions which should be established with spins excited in the steady-state free precession (SSFP) method, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90° between the echoes induced by water and fat, constructing a tomographic image by performing frequency transformation on the acquired echoes, compensating the transformed data for the inhomogeneity in a static magnetic field and reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation.

Abstract: An object of the present invention is to acquire data, which is used to construct a water component-enhanced/fat component-suppressed image, with a repetition time TR set to a desired value. Included are a data acquisition unit and an image construction unit. The data acquisition unit acquires data D_?fat according to a steady-state pulse sequence specifying that the phase of an RF pulse is varied in order of 0, 1×?fat, 2×?fat, etc. Herein, ?fat=(2?TR/T_out+2×m)×? is established on the assumption that m denotes an integer equal to or larger than 0 and meets TR/(2×T_out)?1<m<TR/(2×T_out) where TR denotes the repetition time and T_out denotes the time during which spins in water and spins in fat are out of phase with each other due to chemical shifts. The image construction unit constructs an MR image Gw using the data D_?fat.

Abstract: An MR imaging includes acquiring echoes from the object by implementing a pulse sequence which specifies the conditions which should be established with spins excited in the steady-state free precession (SSFP) method, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90° between the echoes induced by water and fat, constructing a tomographic image by performing frequency transformation on the acquired echoes, compensating the transformed data for the inhomogeneity in a static magnetic field and reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation.

Abstract: An MRI method comprising preparing at least two pulse sequence databases (PSDs) assumed to have the same echo time (TE) and different repetition times (TR), driving a magnet system of an MRI apparatus in accordance with the two PSDs and collecting MR signals at that time, generating an MR image from MR signals collected in accordance with the PSDs, and weighting a tissue having a specific T1 value with reference to an image corresponding to a found difference between two MR images.

Abstract: For the purpose of reducing degradation of image quality due to attenuation of signal intensity, or satisfactorily rendering blood flow even when fast blood flow and slow blood flow are simultaneously present in an imaged region, an imaged region A is divided into a plurality of adjacent slabs; RF pulses are transmitted with a flip angle profile whose flip angle &agr; varies with respect to the thickness direction in each of the slabs and whose average flip angle differs for each of the slabs, to collect NMR signals; and blood flow imaging is conducted based on the NMR signals.

Abstract: For the purpose of identifying the phases of water and fat in a complex image captured using magnetic resonance, a complex image G1 is divided into a multiplicity of sections; if the phases of water and fat can be identified from a phase histogram of one section Sc, the phases of water and fat are obtained from a phase histogram of the section; if the phases cannot be identified, phase histograms of proximate sections in a predefined range C1 are added; if the phases of water and fat can be identified from the additive phase histogram, the phases of water and fat are obtained from the additive phase histogram; and if the phases cannot be identified, the same processing is repeated with stepwise enlargement of the predefined range.

Abstract: For the purpose of providing a magnetic resonance imaging apparatus for capturing water/fat-separated images free of banding artifacts in an SSFP state, an apparatus comprises: acquiring means (202) for acquiring echo data of a plurality of views in which a phase difference between water and fat is 2&pgr;/m with spins within a subject brought to the SSFP state and repeating the acquisition for k=0 through M−1 with a step difference in a phase of an RF pulse of 2&pgr;·k/M; transforming means (204) for conducting Fourier transformation on the echo data based on the phase step difference; separating means (206) for separating water data and fat data respectively in F(0) term and F(1) term of the Fourier-transformed data using the phase difference between water and fat; adding means (208′) for obtaining a sum of absolute values of at least the water data or fat data in the F(0) term and F(1) term; and image producing means (210′) for producing an image based on the sum data.

Abstract: For the purpose of accurately measuring and correcting a phase error in spins in a phase axis direction, a gradient magnetic field having an integral value of zero is applied in the phase axis direction during a time period between first and second 180° excitations to read out a first spin echo SE1; a gradient magnetic field having an integral value of zero is applied in the phase axis direction during a time period between second and third 180° excitations to read out a second spin echo SE2; and a phase error due to an effect of residual magnetization Gp0 is determined based on these spin echoes.