Ge Yokogawa Medical Systems, Limited

Ge Medical Systems Global Technology Company, LLC

Tetsuji Tsukamoto

Yuji Iwadate

Tsutomu Nakada

Koichi Oshio

Naoyuki Takei

Hiroyuki Kabasawa

Eiji Yoshitome

Nobuyuki Tasaka

For the purpose of preventing development of motion artifacts and improving image quality, a first displacement Nof the diaphragm before a scanning sectionperforms an imaging sequence and a second displacement Nof the diaphragm after the scanning sectionhas performed the imaging sequence are detected by a body motion detecting sectionas displacement caused by respiratory motion of a subject. Thereafter, based on the first displacement Nand second displacement Nof the diaphragm detected by the body motion detecting section, imaging data is selected as raw data by a raw data selecting sectionThen, based on the imaging data selected as raw data by the raw data selecting sectiona slice image of the subject is produced by an image producing section

Apparatus and method for reducing image artifact

The present invention provides an MRI apparatus which prevents from developing body move artifacts on the image to improve the image quality. In the navigator sequence a scan unit emits first RF pulse so as to excite first slice plane area which is out of the imaging area and is intersecting the navigator area including the epiglottis, then it emits second RF pulse so as to excite second slice plane area which is out of the imaging area and is intersecting the first slice plane area in the navigator area including the epiglottis. Thereafter a body move detector detects the displacement of epiglottis due to the deglutition movement based on the navigator echo data, a raw data selector unit selects as raw data the imaging data thus obtained in the imaging sequence based on the displacement of epiglottis, then the image of the slice plane including the esophagus in the subject is generated from the imaging data thus selected.

Magnetic resonance imaging apparatus

With a view to providing a receiving coil which permits a subject to assume a supine position when radiographing the breast of the subject, thereby improving the working efficiency, a receiving coil for receiving a magnetic resonance signal from the breast of a subject lying within a static magnetic field space is provided in each of a first cup and a second cup of a brassiere which cups receive the breast of the subject SU therein.

RF receiving coil apparatus and magnetic resonance imaging apparatus

In order to provide a spin excitation method and apparatus for performing imaging with good efficiency while keeping within an SAR limit, and a magnetic resonance imaging apparatus employing such a spin excitation apparatus, an SAR of an object to be imaged in executing a pulse sequence is predicted ( ); and at least one among the number of pulses, pulse waveform and pulse width of the RF pulses in the pulse sequence is adjusted ( ) so that the predicted SAR value falls within a predetermined limit.

Imaging with spin excitation while keeping within a specific absorption ratio limit

In order to provide a magnetic resonance signal collection method and apparatus that suppress false images caused by motion of an imaged object, the order of selecting trajectories a-p is randomized. Alternatively, the angular difference is set at 90&deg; between first and next trajectories, and then new trajectories are defined so that the angular difference between adjacent trajectories is a repeatedly bisected angle in sequence.

Magnetic resonance random trajectory collection method and apparatus

For determining appropriately the direction of diffusive motion detecting gradient magnetic field to be applied for the measurement of the diffusion coefficient of a region of interest, a determining method produces three diffusion-weighted images by use of imaging pulse sequences which apply diffusive motion detecting gradient magnetic fields (MPG) along the x axis, y axis and z axis: (steps S1-S3). It composes an image from the diffusion-weighted images by allotting red color, green color and blue color to the images: (step S4). It sets a region of interest on the intensity-inverted image: (step S6). It determines the direction of diffusive motion detecting gradient magnetic field (MPG) to be applied for the measurement of the diffusion coefficient of the region of interest based on the hue of the region of interest on the intensity-inverted image: (step S7). It applies the diffusive motion detecting gradient magnetic field (MPG) in the determined direction to measure the diffusion coefficient of the volume of the region of interest by use of a diffusion coefficient measuring pulse sequence: (steps S8, S9).

Method of determining the direction of application of gradient magnetic field for the detection of diffusive motion, method of measuring the diffusion coefficient, and MRI apparatus

In order to shorten imaging time in MR imaging, when a partial region A1 is imaged using a fast pulse sequence, a selectively excited region E90 and a selectively inverted region E180 are intersected with each other so as not to include a partial region A2 to be imaged next within the selectively excited region E90 and the selectively inverted region E180.

MR imaging method and apparatus

A diffusion sensitizing imaging method and MRI apparatus capable of reducing image pickup time and thereby suppress artifacts attributable to body movement, wherein an RF pulse of 90.degree. is applied to a diagnostic portion so that spins are created therein; and an RF pulse of 180.degree. is applied on expiration of a time length TE/2 so as to reverse the spins; an echo is imaged; and the image after an echo center is sampled; and the RRF pulse application is such that the gradients of the read out axis and the warp axis form a spiral trajectory which extends in a spiral form from the center to the end of the k-space; and wherein before and after application of the 180.degree. RF pulse, strong motion probing gradients, for diffusion sensitization, are applied to an arbitrary gradient axis; and wherein the phase of the MR data is modified based on the phase of the MR data at the center of the k-space, or based on the average phase of the MR data at the center of the k-space.

Diffusion sensitizing imaging method and MRI apparatus

An MRI apparatus applies an exciting pulse R1 and a slicing gradient S1 which excites a slice S. Subsequently, it applies a diffusion sensitizing gradient MPG1. Next, it applies a reversing pulse R2 and an FOV limiting gradient RS which limits the data collecting region to have a narrow FOV. Next, it applies a diffusion sensitizing gradient MPG2. Next, it applies a positive and negative reading gradients RA and RB m times alternately and cyclically, and collects MR data from the multiple imaged echoes el.about.em, while applying phase encoding gradients W. The phase encoding gradient W has its amplitude-time product set to be 1/(.gamma..multidot.FOV), where .gamma. is the magnetogyric ratio. The apparatus produces a diffusion sensitized image at a practical spatial resolution, with artifacts attributable to the body movement being alleviated in exchange for a narrow FOV in the phase encoding axis direction.

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Tokyo, Japan

Tetsuji Tsukamoto