Hitachi, Ltd.

Hitachi Medical Corporation

Fujifilm Healthcare Corporation

Fujifilm Corporation

The Bank of Tokyo-mitsubishi Ufj, Ltd.

Shinji Kurokawa

Yo Taniguchi

Toru Shirai

Hisaaki Ochi

Suguru Yokosawa

Yushi Tsubota

Hiroyuki Takeuchi

Shinichi Kojima

Masahiro Takizawa

Yoshitaka Bito

Yasutaka Konno

Fumito Watanabe

Keisuke Yamakawa

Hiroki Shoji

Takayuki Abe

Shin-ichiro Umemura

Kosuke Ito

Yasuhiro Kamada

Takenori Murase

Makoto Shibata

Kousuke Itou

Nobuyuki Yoshizawa

Yusuke Hoshino

Akiko Kaneta

Atsuo Ikeya

Takeshi Iketani

Norihiko Ozawa

Yuji Kitada

A problem of time elongation in image reconstruction due to necessity of many iterations is solved, when an image is reconstructed by performing iterative approximation on measurement data acquired by an MRI apparatus without full-sampling. Density is estimated in the course of the iteration, and density is corrected using thus estimated density. Density estimation is performed not only on initial values but also on every iteration process, thereby enabling convergence with a smaller number of iterations.

Magnetic resonance imaging apparatus, image processor, and image processing method

Provided is a magnetic resonance imaging apparatus with no occurrence of artifacts, even after noise removal by applying Wavelet transform to a zero-fill reconstructed image. Nuclear magnetic resonance signals acquired by the magnetic resonance imaging apparatus are processed to perform reconstruction with a reconstruction matrix extended by zero-filling an acquisition matrix, and then a zero-fill reconstructed image is produced. This reconstructed image is subjected to an iterative operation combining the Wavelet transform and L1 norm minimization to remove noise. Before the noise removal, a pre-processing is performed to change the reconstruction matrix size so that an artifact does not occur in the image after noise removal, an artifact portion appears outside the reconstruction matrix after the noise removal, or cutting out is performed so that no artifact appears after the noise removal. The matrix size is restored to its original size in the post-processing after the noise removal.

Magnetic resonance imaging apparatus and image processing method

During obtaining a sensitivity distribution in a k-space, data based on which the sensitivity distribution is obtained is expanded with a mirror image to create an expanded image to prevent spectrum leakage, and the sensitivity distribution is stably calculated. During obtaining the sensitivity distribution in the k-space, image data based on which the sensitivity distribution is obtained is inverted as a mirror image to be made into the expanded image, the expanded image is transformed into k-space data, and a frequency component (frequency space data) of the sensitivity distribution is calculated. A region corresponding to the original image data is clipped from the calculated frequency space data, and the sensitivity distribution is obtained.

Magnetic resonance imaging device and sensitivity distribution calculation program

A technology of improving image quality of a calculation image or parameter estimation accuracy even in a case where a method of simultaneously generating calculation images of a plurality of parameters is used is provided. Thus, by utilization of a reconstructed image in an optimal resolution of each parameter to be estimated, a value of the parameter is estimated and a calculation image that is a distribution of the value of the parameter is acquired. A reconstructed image in an optimal resolution is acquired by adjustment of a resolution of a reconstructed image acquired in an optimal resolution of an estimation parameter with the highest optimal resolution among parameters to be estimated in scanning. Alternatively, in scanning, only a reconstructed image used for calculation of a predetermined parameter to be estimated is acquired in an optimal resolution of the parameter to be estimated.

Magnetic resonance imaging apparatus

Provided is a novel aliasing elimination technique capable of suppressing noise amplification in an aliasing elimination calculation in parallel imaging and the like. The technique utilizes the fact that a phase of an image (a true image that is one of a plurality of images) to be separated from a main captured image obtained with the plurality of images superimposed is basically the same as a phase of an image obtained at a low resolution, to obtain a phase difference between a phase of a low-resolution image and a phase of the main captured image, and separates the true image by calculation using the phase difference and a pixel value of the main captured image. At this time, the low-resolution image is obtained by each of a plurality of receiving coils, and the true image is calculated after multiplying a plurality of low-resolution images by a complex number that minimizes the noise amplification.

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.

In multi-echo imaging, in imaging in which pulses other than a 180&#xb0; pulse are included in refocus RF pulses, a high-quality image in which the intended contrast is emphasized is obtained by reducing unnecessary contrast. Therefore, imaging parameters are adjusted so as to reduce the unnecessary contrast. The adjustment is performed so that, for echo signals from tissues having the same relaxation time to cause intended contrast among echo signals from a plurality of tissues having different relaxation times, the difference between the signal strengths of echo signals to determine the contrast, such as echo signals at the k-space center, is reduced. Imaging parameters to be adjusted include a repetition time, the FA of a DE pulse, the FA of a saturation pulse, the application timing of the saturation pulse, the application strength of a gradient magnetic field in a recovery period, application timing, and the like.

Magnetic resonance imaging apparatus and method for reducing unnecessary contrast

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.

An X-ray CT device which improves resolution in a peripheral region distant from a rotation center. According to an FFS method of moving an X-ray focal point, a gap width of projection positions on an X-ray detector of a first X-ray trajectory from the X-ray focal point of a first view and a second X-ray trajectory from the X-ray focal point of a second view is obtained. A position of the X-ray focal point of the first and second views is set so that a gap widthof the projection positions on the X-ray detector of the first X-ray trajectory and the second X-ray trajectory which pass through a point within a predetermined first region close to the X-ray focal point from the rotation center is closer to (N&#x2212;&#xbd;) times (N=any one of 1, 2, 3, . . . ) of a width of a channel of the X-ray detector.

X-ray CT device and imaging method for X-ray CT images

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.

Medical image processing and diagnostic image generation device for predetermined types of diagnostic information

In order to maximize the SNR of an image in consideration of signal correction in a multi-echo sequence, flip angles of a plurality of refocus high frequency magnetic field pulses are determined in a multi-echo imaging sequence. Using an index that reflects the SNR of an image after signal correction of a plurality of acquired echo signals, a flip angle at which the SNR of the image becomes a maximum is determined by repeatedly calculating the index by changing information specifying the flip angle of each refocus RF pulse according to an optimization method set in advance.

Magnetic resonance imaging apparatus and flip angle determination method

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.

Magnetic resonance imaging apparatus and method for calculating pulse sequence to be carried on magnetic resonance imaging apparatus

A change of X-ray radiation quality due to a material existing between an X-ray source and a detection element is estimated and corrected. Accordingly, deterioration of material discrimination ability in a dual energy imaging method can be prevented. An X-ray imaging apparatus is provided with an inherent filtration calculator configured to use measured data obtained by imaging air at two or more types of different tube voltages to calculate a deviation from a reference radiation quality, as a transmission length (inherent filtration) of a predetermined reference material. A reference-material transmission-length conversion is applied to the measured data according to the dual energy imaging method, thereby calculating the reference material transmission length (inherent filtration). When a subject is imaged, the dual energy imaging is performed by adding the inherent filtration calculated as to each detection element, and this produces an image with the change of radiation quality having been corrected.

X-ray image pickup apparatus, X-ray image pickup method, and X-ray image pickup apparatus monitoring method

Provided is a technique in an X-ray imaging apparatus for implementing data interpolation approximating an ideal point response trajectory interpolation, along with reducing calculation load. A method is provided to perform interpolation at high speed, in a direction along the point response trajectory. Sinograms are interpolated in advance from measured data, as to representative angles (e.g., 0&#xb0;, &#xb1;30&#xb0;, &#xb1;60&#xb0;, and 90&#xb0;) only. When a pixel targeted for back projection is determined at the time of reconstruction, a slope of the point response trajectory is determined as to each view. According to the slope of the trajectory, each representative sinogram is added with weight, whereby interpolation data in association with any angle can be obtained.

X-ray image pickup device and image reconstruction method

Realized is a low-cost provision system capable of providing a provision item or a provision system that requires a smaller number of operation steps to be made by a user. A server includes a first receiving unit receiving transaction information transmitted by a communication terminal requesting a provision device having a provision item stored thereon to make a transaction of the provision item, a second receiving unit receiving a communication result including authentication information input to the communication terminal before the communication, the communication result being generated by a communication between the provision device and the communication terminal, and a transmission unit transmitting an instruction to execute the transaction to the provision device based on the transaction information or the communication result.

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Tokyo, Japan

Shinji Kurokawa