Hitachi, Ltd.

Hitachi Medical Corporation

Fujifilm Healthcare Corporation

Yo Taniguchi

Hisaaki Ochi

Toru Shirai

Yoshitaka Bito

Suguru Yokosawa

Tetsuhiko Takahashi

Shinji Kurokawa

Tomoki Amemiya

Etsuji Yamamoto

Yoshihisa Soutome

Satoshi Hirata

Hiroyuki Takeuchi

Hiroyuki Itagaki

Masahiro Takizawa

Shinichiro Umemura

Ryota Sato

Ryota Satoh

Takenori Murase

Yoshihisa Sotome

Kenichi Okajima

Kenji Takiguchi

Yukari Onodera

Takashi Azuma

Yoshitaka Sato

Shin-ichiro Umemura

Yukio Kaneko

Takeshi Yatsuo

Shigeru Watanabe

Hidemi Shiono

Ryuzaburo Takeda

Masaharu Ono

Shinji Kawasaki

Yukari Yamamoto

Atsushi Kuratani

Katsunori Suzuki

Kazuho Kamba

Shoichi Miyawaki

Yoru Shirai

Ken'ichi Okajima

Yuki Kanazawa

Shoji Kondo

To provide a technique of stably obtaining quantitative parameter maps by preventing influences of artifacts caused by flow or body motion when calculated images with a plurality of parameters are generated at the same time. When a calculated image of a subject parameter or an apparatus parameter is generated by using a plurality of images obtained by performing imaging under different imaging conditions, an imaging condition under which the artifacts are easy to occur is examined in advance, and an imaging parameter set for quantitative parameter map calculation is optimized by excluding the imaging condition under which the artifact is easy to occur.

Magnetic resonance imaging apparatus and image processing method

Distortion generated in an image is effectively corrected in imaging using an EPI sequence such as DWI without extending an imaging time. After one excitation RF pulse of EPI is applied, a navigator scan in which the polarity of the phase encoding is opposite to that of the main scan is performed continuously to the main scan, and the distortion of the image by using the navigator scan data obtained by the navigator scan is corrected. In a case of multi-shot, phase information obtained from the navigator scan data for each shot is used to perform phase correction and multi-shot reconstruction on the main scan data of each shot.

Magnetic resonance imaging device and control method thereof

In MRI, upon simultaneously generating computed images of multiple parameters, imaging time is efficiently reduced while preventing decrease in spatial resolution and SN ratio as much as possible. A plurality of original images is reconstructed from nuclear magnetic resonance signals acquired under various imaging conditions, and a computed image is obtained by calculation performed among the plurality of original images. The various imaging conditions include an imaging condition that a repetition time of an imaging sequence is different from one another, and upon imaging, the number of phase encoding steps is made smaller when the repetition time is long. An image is reconstructed in such a manner that a matrix size of the image obtained when the number of phase encoding steps is small is made equal to the matrix size of the image obtained when the number of phase encoding steps is large.

Magnetic resonance imaging apparatus and magnetic resonance imaging method

A myelin image is generated with a stable contrast regardless of an imaging condition with an MRI apparatus that measures an echo signal generated from a subject by applying a high-frequency magnetic field and a gradient magnetic field to the subject placed in a static magnetic field according to a predetermined imaging sequence. A reconstructed image is obtained from the echo signal. A distribution of a quantitative value of the subject is estimated using a plurality of the reconstructed images, each of which is obtained by a plurality of types of imaging having different imaging conditions of the imaging sequence, and a signal function defining a relationship between the quantitative value of the subject and a signal value of the reconstructed image. An image generation unit generates an arbitrary image from the distribution of the quantitative value.

Image processing apparatus, magnetic resonance imaging apparatus including the same, and magnetic resonance imaging system

An MRI device for executing an imaging operation at least three times or more with a different combination of at least a repetition time and a flip angle in the same imaging sequence, includes: a receiving unit which receives information specifying an imaging target and a constraint condition relating to an imaging time or quantitative value accuracy; and a scan parameter set generation unit which calculates at least three or more scan parameter sets having a different combination of at least the repetition time and the flip angle on the basis of the constraint condition. The MRI device uses three or more scan parameter sets generated by the optimal scan parameter set generation unit and calculates quantitative values (TTand the like) of the imaging target from a plurality of images obtained by the imaging operation.

Magnetic resonance imaging device, calculation device for generation of imaging parameter set, and imaging parameter set generation program

Two or more learning images generated for a first subject or a second subject and one or more correct answer images generated for the second subject or a third subject are received. In a case where pixel values of corresponding pixels of the two or more learning images are synthesized by using a synthesis parameter value, the parameter value at which the synthesized pixel values are close to a pixel value of a corresponding pixel of the correct answer image is obtained. An image generated for the first subject and having the same type as the two or more learning images is received as an examination target image. A synthesized image desired by a user is generated by synthesizing pixel values of corresponding pixels of the two or more examination target images by using the synthesis parameter value.

Medical image diagnosis support device and magnetic resonance imaging apparatus

An MRI apparatus in which, when a quantitative value, which does not depend on imaging parameter values, is computed from a plurality of image data having different pixel values that are acquired by performing imaging the plurality of times with different imaging parameter values in the same pulse sequence, pixel values which are acquired from the imaging parameter values are predicted for each of a plurality of predetermined quantitative-value candidate group, and an initial value of the quantitative value is selected from the quantitative-value candidate groups with reference to the predicted pixel values. The optimal quantitative value is computed through a localized optimization technique using the selected initial value.

Magnetic resonance imaging apparatus and quantitative-value computing program

A system is disclosed to simultaneously acquire a magnetic resonance angiography (MRA) image and a plurality of images in which the structure of a tissue other than a blood vessel can be ascertained without performing imaging for the MRA image, and to shorten a time of MR examination. Two or more kinds of physical property dependent images obtained from a nuclear magnetic resonance signal measured in accordance with a predetermined pulse sequence under a plurality of imaging conditions are combined using a predetermined combination function. At this time, a plurality of division regions are set in the physical property dependent image, and the combination parameter satisfying a condition that a difference between a pixel value of the specific tissue and a pixel value of a tissue other than the specific tissue increases is determined at each of the division regions in the actually measured two or more kinds of physical property dependent images, using standard data of the two or more kinds of physical property dependent images, and the combination parameter is used to combine the two or more kinds of images.

Magnetic resonance imaging apparatus and magnetic resonance image processing method

To provide an MRI apparatus that acquires a plurality of contrast images including an FLAIR image in the shortest imaging time. An imaging controller of the MRI apparatus includes, as a prescribed pulse sequence, an IR (inversion recovery) sequence that includes application of an inversion pulse and a signal acquisition sequence to collect a signal after an inversion time has elapsed from the application of the inversion pulse, and acquires images in a first slice group, and an imaging sequence that is inserted into an inversion pulse of the IR sequence at a single time and an inversion pulse of the IR sequence at the next time, and acquires images in a second slice group different from the first slice group that are images having different contrasts from that of the IR sequence.

Magnetic resonance imaging apparatus and control method thereof

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.

Magnetic resonance imaging device, magnetic resonance imaging method and susceptibility 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

A medical image diagnosis supporting apparatus includes a quantitative value reception unit that receives data of kinds of quantitative values obtained in advance at points in a region of a subject; a variable conversion unit that calculates kinds of intermediate information values dependent on the kinds of quantitative values at each of the points using the kinds of quantitative values at each of the points and kinds of variable conversion functions; and a diagnosis image calculation unit that calculates a diagnosis image for the region. The diagnosis image calculation unit sets a pixel value at each of the points in accordance with a combination of kinds of intermediate information values obtained at each of the points by the variable conversion unit or a combination of intermediate information values and kinds of quantitative values at the point and generates the diagnosis image.

Medical image diagnostic assistance device and magnetic resonance imaging device

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.

Magnetic resonance imaging apparatus and calculation image generation method using pulse sequence

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.

Magnetic resonance imaging device, magnetic resonance imaging system, and parameter estimation method

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.

Growing community of inventors

Tokyo, Japan

Yo Taniguchi