Ge Medical Systems Global Technology Company, LLC

General Electric Company

Ge Yokogawa Medical Systems, Limited

Mitsuharu Miyoshi

Aki Yamazaki

Susumu Kosugi

Koichi Oshio

Naoyuki Takei

A magnetic resonance imaging apparatus comprises a scanning unit for performing a pulse sequence PS including a MT (Magnetization Transfer) pulse b for lessening signals from the cerebral parenchyma (white matter and gray matter). The scanning unit performs the pulse sequence PS in periods of time Pand Pin the pulse sequence PS so that the MT pulse b is applied every repetition time TR, while it performs the pulse sequence PS in a period of time Pin the pulse sequence PS so that no MT pulse b is applied.

Magnetic resonance apparatus

For the purpose of obtaining a spectrum suitable for acquiring information on a CEST effect, an MR apparatus comprises a Z-spectrum generating unitfor generating a Z-spectrum containing a CEST component representing a signal component affected by CEST and a baseline component representing a signal component unaffected by CEST based on data acquired by a plurality of sequences; a spectrum transforming unitfor transforming the Z-spectrum into a CPE spectrum; and first fitting unitfor calculating values of a plurality of coefficients included in a CEST term in an approximate expression of the CPE spectrum.

Magnetic resonance system and method for obtaining a Z-spectrum of a CEST imaging technique

A magnetic resonance apparatus is provided. The magnetic resonance apparatus includes a scanner configured to execute a plurality of pulse sequences each including a plurality of RF pulses for generating magnetization transfer of protons and a data acquisition sequence for acquiring data from a region in which proton magnetization transfer occurs, wherein the phases of the plurality of RF pulses are cycled so as to make a phase difference between the phase of a pth RF pulse of the plurality of RF pulses and the phase of a p+1th RF pulse of the plurality of RF pulses different for each pulse sequence, and a controller configured to control operations that include processing for determining a spectrum indicative of a relationship between a signal intensity of each signal obtained from the region and the associated phase differences based on data obtained by executing the plurality of pulse sequences.

Magnetic resonance apparatus and method using thereof

An MRI apparatus which images a subject in such that body fluid that flows is emphasized over background tissues, includes a first coil control device that causes a transmission coil and a gradient coil to execute a first pulse sequence for causing longitudinal magnetization components of the background tissues to differ from a longitudinal magnetization component of the body fluid, a second coil control device that causes the transmission coil and the gradient coil to execute a second pulse sequence that inverts the longitudinal magnetization components of the body fluid and the background tissues a plurality of times after the execution of the first pulse sequence, and a third coil control device that causes the transmission coil and the gradient coil to execute a third pulse sequence for acquiring each MR signal of the body fluid after the execution of the second pulse sequence.

MRI apparatus for imaging body fluids by suppressing the background tissues

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.

Magnetic resonance imaging apparatus

A magnetic resonance imaging (MRI) apparatus sequentially transmits a plurality of radio frequency (RF) pulses having flip angles of &#x3b1;1&#xb0;, &#x3b1;2&#xb0;, &#x2212;&#x3b1;1&#xb0;, and &#x2212;&#x3b1;2&#xb0; for refocusing transverse magnetization of spins, and brings the transverse magnetization of the spins to longitudinal magnetization after the refocusing of the transverse magnetization of the spins.

Magnetic resonance imaging apparatus and method utilizing RF pulse flip angels

A magnetic resonance imaging apparatus includes a coil control device that controls a transmission coil and a gradient coil such that (A) a longitudinal magnetization adjustment pulse sequence for setting a longitudinal magnetization component positive in value of a first body fluid smaller than a longitudinal magnetization component positive in value of a second body fluid is executed on the first and second body fluids, (B) a longitudinal magnetization reverse pulse for reversing the longitudinal magnetization components of the first and second body fluids is transmitted, and (C) a data acquisition pulse sequence for acquiring data of the first body fluid when an absolute value of the longitudinal magnetization component of the first body fluid flowing through an imaging area is larger than an absolute value of the longitudinal magnetization component of the second body fluid, is executed.

Magnetic resonance imaging apparatus and method for controlling the velocity of venuous and arterial blood

An MRI apparatus for imaging 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.

MRI apparatus

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 that executes an imaging pulse sequence after executing a preparation pulse sequence to transmit preparation pulses. The scanning unit, during the preparation pulse sequence, excites a spin of the subject by successively transmitting a first chemical saturation pulse, a T2 preparation pulse and a second chemical saturation pulse, which is a reversed pulse; transmits a first killer gradient pulse after transmitting the first chemical saturation pulse and before transmitting the T2 preparation pulse; transmits a second killer gradient pulse after transmitting the T2 preparation pulse and before transmitting the second chemical saturation pulse; and transmits a third killer gradient pulse after transmitting the second chemical saturation pulse and before executing the imaging pulse sequence.

Magnetic resonance imaging apparatus and magnetic resonance image generating method

An MR data acquisition method for acquiring data D_&#x3c6;fat according to a steady-state pulse sequence specifying that a phase of an RF pulse is varied in order of 0, 1&#xd7;&#x3c6;fat, 2&#xd7;&#x3c6;fat, etc., wherein &#x3c6;fat=(2&#x2212;TR/T_out+2&#xd7;m)&#xd7;&#x3c0; is established on an assumption that m denotes an integer equal to or larger than 0 and meets TR/(2&#xd7;T_out)&#x2212;1&#x3c;m&#x3c;TR/(2&#xd7;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.

MR data acquisition method, MR image construction method, and MRI system

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 RF pulse is transmitted as the second RF pulse is interposed at a time base, wherein the scan section transmits a second 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 RF pulse is transmitted as the third RF pulse is interposed at the time base, and wherein the scan section transmits a killer gradient pulse to the subject after the transmission of the fourth RF pulse.

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.

Magnetic resonance imaging apparatus and magnetic resonance imaging method

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.

MRI apparatus and method for performing spatial selective saturation

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_&#x3c6;fat according to a steady-state pulse sequence specifying that the phase of an RF pulse is varied in order of 0, 1&#xd7;&#x3c6;fat, 2&#xd7;&#x3c6;fat, etc. Herein, &#x3c6;fat=(2&#x2212;TR/T_out+2&#xd7;m)&#xd7;&#x3c0; is established on the assumption that m denotes an integer equal to or larger than 0 and meets TR/(2&#xd7;T_out)&#x2212;1&#x3c;m&#x3c;TR/(2&#xd7;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_&#x3c6;fat.

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&#x3c0;/m with spins within a subject brought to the SSFP state and repeating the acquisition for k=0 through M&#x2212;1 with a step difference in a phase of an RF pulse of 2&#x3c0;&#xb7;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.

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Tokyo, Japan

Mitsuharu Miyoshi