Abstract: A flexible RF coil with excellent portability is provided. The RF coil includes a first coil, a first skeleton, and a second skeleton, the first skeleton and the second skeleton being rod shaped. The first coil includes a first loop made from a conductor that receives radio frequency signals, and a first signal detector that is inserted in series into the first loop and that detects the signals received by the first loop. The first skeleton and the second skeleton are arranged with a spacing in the short axis direction, the first signal detector is mounted on the first skeleton, and a portion of the first loop that faces the first signal detector is mounted on the second skeleton. The first loop is deformable, and the spacing between the first skeleton and the second skeleton is changeable in accordance with the deformation of the first loop.

Abstract: In calculating a local magnetic field distribution caused by a magnetic susceptibility difference between living tissues, using MRI, a local frequency distribution with a high SNR is calculated in a short computation time. Multi-echo complex images obtained by measurement of at least two different echo times using the MRI are converted into low-resolution images. A global frequency distribution caused by global magnetic field changes and an offset phase distribution including a reception phase and a transmission phase are separated from a phase distribution of the low-resolution multi-echo complex images. Thus calculated global frequency distribution and the offset phase distribution are enhanced in resolution. A local frequency distribution of each echo is calculated from the measured multi-echo complex images, the high-resolution global frequency distribution, and the high-resolution offset phase distribution.

Abstract: An automatic clipping technique capable of satisfactorily extracting blood vessels to be extracted is provided. A specific tissue extraction mask image which is created by extracting a specific tissue (for example, a brain) from a three-dimensional image acquired by magnetic resonance angiography and a blood vessel extraction mask image which is created by extracting a blood vessel from an area (a blood vessel search area) which is determined using a preset landmark position and the specific tissue extraction mask image are integrated to create an integrated mask. By applying the integrated mask to the three-dimensional image, a blood vessel is clipped from the three-dimensional image.

Abstract: Provided is an image processor including a tissue-segmentation-processing-unit that performs tissue segmentation processing on at least one of a plurality of complex images generated based on a magnetic resonance signal generated from a subject to calculate a tissue-image related to a predetermined specific tissue, a magnetic-susceptibility-image-calculation-unit that calculates a magnetic-susceptibility-image showing magnetic susceptibility of a predetermined tissue included in the complex image from the complex image, an anatomical-standardization-processing-unit that calculates a standard-magnetic-susceptibility-image and a spatially-normalized tissue-image by performing spatially normalization processing on the magnetic-susceptibility-image and the tissue-image and calculates a volume modulated spatially-normalized tissue-image obtained by performing volume modulation on the spatially-normalized tissue-image, a magnetic-susceptibility-calculation-unit that calculates magnetic susceptibility of the specifi

Abstract: In an MRI apparatus, an imaging that produces almost no sound is implemented without extending an imaging time, not only for three-dimensional imaging, but also for two-dimensional imaging. A gradient pulse in a pulse sequence provided in the MRI apparatus is adjusted by using a basic waveform having a distribution of frequencies where strength dwindles substantially as the frequency increases from zero, and the waveform is convex upward or downward varying smoothly. An application time and strength are adjusted so that almost no sound is produced. Any imaging executable by a conventional pulse sequence can be implemented without producing almost any sound, using the conventional pulse sequence with little change.

Abstract: Acoustic noise reduction is achieved in a high-speed imaging method such as a phase-compensation type GE sequence, which is not provided with sufficiently long intervals for applying the gradient magnetic field pulses. A band-stop filter is used to reduce components of a frequency band in the gradient magnetic field waveform, having a high sound pressure level being a source of sound, thereby performing the noise reduction. In general, when a band of the gradient magnetic field is reduced, the waveform is likely to be considerably distorted, failing to satisfy imaging conditions. Therefore, the distorted waveform is shaped so that the imaging conditions are satisfied. The sound pressure level of the gradient magnetic field waveform is calculated by using a response function inherent to the device.

Abstract: A quantitative image (resonance frequency map) of a resonance frequency difference is obtained using a high-speed phase compensated pulse sequence of a gradient echo (GE) system. A signal function of the pulse sequence used when obtaining the resonance frequency map is generated by a numerical simulation. The high-speed phase compensated pulse sequence uses a BASG sequence, for example.

Abstract: Provided is a technique for calculating an oxygen extraction fraction by using MRI where the oxygen extraction fraction in a brain including brain parenchyma is calculated via a simple processing without an impact on an examinee, such as administration of caffeine. For this purpose, an MRI apparatus of the present invention measures a complex image of nuclear magnetic resonance signals, and calculates from thus measured complex image, a physical property distribution for obtaining a physical property image reflecting the oxygen extraction fraction. Then, thus calculated physical property distribution is separated into tissue-specific physical property distributions for at least two tissues (separated tissue images). After converting any of the separated tissue images into the oxygen extraction fraction, a distribution of the oxygen extraction fraction is estimated based on the condition that a value of any selected pixel is substantially equal to a mean value of pixels surrounding the selected pixel.

Abstract: A plurality of subject parameter maps are acquired at high speed. In addition to using an imaging sequence for generating both a gradient echo and a spin echo in a single imaging sequence, one or more parameters such as the longitudinal relaxation time T1 and the apparent transverse relaxation time T2* are calculated using the gradient echo and another parameter such as true transverse relaxation time T2 is calculated using the spin echo. When a value of one parameter is calculated, a value of the parameter calculated at the time of calculating the other parameter can be used.

Abstract: In a case where a subject parameter distribution is obtained using MRI, a magnetization transfer effect is suppressed such that the calculation accuracy of T1 and T2 of brain parenchyma can be improved and a variation in the T1 value of blood caused by the effect of blood flow can be reduced. In imaging for parameter estimation, a magnetization transfer effect is suppressed by using a high frequency magnetic field pulse having a narrow frequency band as an excitation pulse. In a case where the frequency band is narrow, the high frequency magnetic field pulse has a shape in which the excitation profile is similar to a Gaussian function. A rising portion of the shape is arranged in a field of view where the head is an imaging target.

Abstract: In calculating a local magnetic field distribution caused by a magnetic susceptibility difference between living tissues, using MRI, a local frequency distribution with a high SNR is calculated in a short computation time. Multi-echo complex images obtained by measurement of at least two different echo times using the MRI are converted into low-resolution images. A global frequency distribution caused by global magnetic field changes and an offset phase distribution including a reception phase and a transmission phase are separated from a phase distribution of the low-resolution multi-echo complex images. Thus calculated global frequency distribution and the offset phase distribution are enhanced in resolution. A local frequency distribution of each echo is calculated from the measured multi-echo complex images, the high-resolution global frequency distribution, and the high-resolution offset phase distribution.

Abstract: Accuracy degradation due to a signal loss is reduced, and susceptibility is calculated with high accuracy where, by using an MRI, at least one echo is acquired where spatial magnetic field inhomogeneity is reflected, and a complex image is calculated from the acquired echo. Three masks are calculated from the calculated complex image; a low-signal region mask representing a low signal region, a first high-signal region mask representing a high signal and high fat content region, and a second high-signal region mask representing a high signal and low fat content region. In calculating a susceptibility image from a frequency image or a magnetic field image generated from the complex image, the susceptibility image is obtained under the constraint that a region defined by the low-signal region is set as a background and the susceptibility of the region defined by the second high-signal region mask is set to a specific value.

Abstract: Provided is a technique in calculating a magnetic susceptibility distribution by using an MRI, for reducing artifacts and noise and improving precision in the magnetic susceptibility distribution being calculated. According to this technique, a magnetic field distribution is obtained via a phase image from a complex image acquired through MRI. Under the constraint based on a relational expression between the magnetic field and the magnetic susceptibility, smoothing process is performed iteratively on the magnetic susceptibility distribution calculated from the magnetic field distribution. Specifically, a minimization process for minimizing through the iterative operation, an error function defined by a predetermined initial magnetic susceptibility distribution and the magnetic field distribution is performed, thereby calculating the magnetic susceptibility distribution.

Abstract: To provide a technique for supporting diagnosis by reducing a user's time and effort in quantitative diagnosis using a quantitative value acquired by a medical image acquisition apparatus. A user is allowed in advance to select only desired diagnostic information from vast amounts of diagnostic information such as images and numerical values. Only the selected diagnostic information is presented to the user in a user-friendly mode. The diagnostic information is calculated by using a physical property value necessary for the calculation of the diagnostic information in question and calculation information such as arithmetic functions and variables, the physical property value and calculation information being stored in advance.

Abstract: A magnetic resonance imaging apparatus comprising a measurement parameter-setting unit for setting measurement parameters that determine the strength and timing of the high frequency magnetic field and the gradient magnetic field, and a measuring unit for applying the high frequency magnetic field and the gradient magnetic field on a subject placed in the static magnetic field according to the measurement parameters and detecting the nuclear magnetic resonance signal generated from the subject as a complex signal. The measurement parameter-setting unit is equipped with: a basic parameter-inputting section for setting the imaging parameters and imaging cross-section; a limiting condition-inputting section for setting limiting conditions that apply limits on the setting of the voxel size; a voxel size-calculating section for setting the voxel size according to the limiting conditions; and a voxel size-displaying section for displaying the set voxel size to the user.

Abstract: When imaging is performed by executing a pulse sequence on an MRI apparatus, silencing is realized with securing sufficient application amount of crusher without extending the application time thereof. In the pulse sequence carried by the MRI apparatus, at least one gradient magnetic field pulse included in the pulse sequence has a waveform synthesized from two or more base waves shifting along the time axis direction (synthesized waveform), and the base waves have a smoothly changing waveform convex upward. The pulse of the synthesized waveform is generated from one or more trapezoidal or triangular base pulses by a waveform conversion part of a computer of the MRI apparatus or an external computer.

Abstract: Restriction on echo intervals is to be reduced in the Dixon's method without sacrificing separation performance and image quality. An image is reconstructed from echo signals measured at three or more different echo times. First and second peak frequency distributions in which aliasing (folding) due to echo time intervals is removed are calculated from the obtained images, and the first and second peak frequency distributions are used to obtain an offset frequency distribution. Note that these first peak frequency distribution and second peak frequency distribution are a distribution of peak frequencies obtained on the assumption that all of the pixels are the first substance and a distribution of peak frequencies obtained on the assumption that all of the pixels are the second substance, respectively. The offset frequency distribution and the obtained images are used to separate an image of the first substance from an image of the second substance.

Abstract: In an MRI apparatus, an imaging that produces almost no sound is implemented without extending an imaging time, not only for three-dimensional imaging, but also for two-dimensional imaging. A gradient pulse in a pulse sequence provided in the MRI apparatus is adjusted by using a basic waveform having a distribution of frequencies where strength dwindles substantially as the frequency increases from zero, and the waveform is convex upward or downward varying smoothly. An application time and strength are adjusted so that almost no sound is produced. Any imaging executable by a conventional pulse sequence can be implemented without producing almost any sound, using the conventional pulse sequence with little change.

Abstract: Provided is a technique in calculating a magnetic susceptibility distribution by using an MRI, for reducing artifacts and noise and improving precision in the magnetic susceptibility distribution being calculated. According to this technique, a magnetic field distribution is obtained via a phase image from a complex image acquired through MRI. Under the constraint based on a relational expression between the magnetic field and the magnetic susceptibility, smoothing process is performed iteratively on the magnetic susceptibility distribution calculated from the magnetic field distribution. Specifically, a minimization process for minimizing through the iterative operation, an error function defined by a predetermined initial magnetic susceptibility distribution and the magnetic field distribution is performed, thereby calculating the magnetic susceptibility distribution.

Abstract: There is provided a technique for obtaining temperature information for inside of a living body and accuracy information thereof in short time with low burden imposed on a subject. It is realized with a spectrum calculator configured to perform MRS or MRSI measurement for two kinds of substances showing difference of resonant frequencies and calculating spectra of magnetic resonance signals of the two kinds of substances, a temperature information calculator configured to calculate temperature information for inside of the subject on the basis of peaks of the calculated spectra, a temperature accuracy information calculator configured to calculate temperature accuracy information indicating accuracy of the temperature information on the basis of peaks of the calculated spectra, and a display information generator configured to generate display information to be displayed on a display device on the basis of the temperature information and the temperature accuracy information.