Hitachi, Ltd.

Hitachi Medical Corporation

Ricoh Company, Ltd.

Tokyo Metropolitan University

Kensuke Sekihara

Hideki Kohno

Shigeru Matsui

Hidemi Shiono

Etsuji Yamamoto

Hiroyuki Kawai

Shinji Yamamoto

Nagaaki Ohyama

Hideo Todokoro

Yoshitaka Bito

Kazutaka Tsuji

Katsuhiro Kuroda

Shigeto Isakozawa

Yasuhiro Mitsui

Mikio Ichihashi

Tatsuo Makishima

Masanari Koguchi

Hiroshi Kakibayashi

Masao Kuroda

Ruriko Tsuneta

Ryuichi Suzuki

Chitose Nakaya

Kuniyasu Nakamura

Teruichi Tomura

Jun Motoike

Takashi Onodera

Yukiko Ogura

Takayuki Hayakawa

Shigenobu Yanaka

Minoru Yoshida

Hisaaki Ochi

Hironori Ueki

Hiroshi Takeuchi

Fumio Kawaguchi

Ken Ueda

Masahiro Yamaguchi

Toshio Honda

Keiji Umetani

Rika Baba

Isao Horiba

Takashi Obi

Taishi Watanabe

Shinichi Migita

Takaji Suzuki

Takeshi Tajima

Kideki Kohno

Hideaki Haneishi

An information acquisition method includes: executing a voxel defining process to divide an area in which a signal source is assumed to be present and define a voxel division Vspecifying resolution of an image; executing a data collecting process to acquire magnetic field data resulting from measurement of a magnetic field generated in the area; and executing a reconstructing process to estimate, by using a mathematical algorithm, a direction and strength of a current of a signal source at a location of each voxel based on the acquired magnetic field data. The reconstructing process includes: calculating a Gram matrix by using a voxel division Vdefined coarser than the voxel division Vand reconstructing, by using the Gram matrix, a direction and strength of a current of a signal source in the voxel division V

Information acquisition method, information acquisition apparatus, and recording medium

3-dimensional observation on the atomic arrangement and atomic species in a thin-film specimen are carried out at high speed and accuracy by an electron microscope which measures electrons emitted at high angle from the specimen. A scanning transmission electron microscope has an electron detection device comprising a scintillator converting electrons detected thereby to photons, a photoconductive-film converting photons from the scintillator detected thereby to c.a. 1000 times as many electron-hole pairs as these photons.

Electron microscope

A scanning transmission electron microscope including an electron detection system having a scattering angle limiting aperture (for the inner angle) and a scattering angle limiting aperture (for the outer angle) between a specimen and an electron detector (comprising a scintillator and a light guide) and only one electron detector is installed.

A computerized tomography system including an X-ray source for emitting X-rays in a cone-beam shape, a two-dimensional X-ray image acquirer which is arranged so as to face the X-ray source and acquires an image of an object by using the X-rays; and rotator for rotating the X-ray source and the two-dimensional x-ray image acquirer around the object, wherein a three-dimensional reconstructed image is formed from the projection images acquired by the two-dimensional X-ray image acquirer while rotating the rotator. An iterative reconstruction calculator for forming the three-dimensional reconstructed image from the projection images is provided. The three-dimensional reconstructed image without artifacts can be acquired from a small amount of projection data.

Computerized tomography system

A method of X-ray computerized tomography whereby a scanner in which an X-ray source for irradiating an X-ray in a cone-beam shape to an object and a two-dimensional detector for detecting the X-ray transmitted through the object are installed is rotated around the object and a projection angle is changed and a distribution of X-ray attenuation coefficients of the object is reconstructed from the transmitted X-ray images obtained at a plurality of projection angles. This method has the steps of: (1) measuring a first transmitted X-ray image measured in a state in which a contrast medium is injected into the object, a second transmitted X-ray image measured in a state in which no contrast medium is injected into the object, and a third transmitted X-ray image measured in a state in which no object is positioned in the apparatus; (2) calculating a first projection image from a difference between logarithms of the first and second transmitted X-ray images obtained at the same projection angle, calculating a second projection image from a difference between logarithms of the second and third transmitted X-ray images obtained at the same projection angle, and simultaneously reconstructing a first reconstructed image from the first projection image and a second reconstructed image from the second projection image in parallel; and (3) composing the first and second reconstructed images, thereby forming a composed image.

Method and apparatus of X-ray computerized tomography

A method for X-ray computed tomography includes a process for rotating around an object an X-ray source for applying a cone-beam X ray and a scanner having a two-dimensional X-ray detector mounted thereon for deriving projection data and a process for preparing a geometric distortion correction table for correcting an image geometric distortion of the two-dimensional X-ray detector for the projection data, for reconstructing a distribution of X-ray attenuation coefficients of the object from said corrected projection data. The method further includes a process for calculating a function for evaluating the correction table, a process for comparing the calculated value with a threshold value, a process for correcting the correction table through the interpolation based on the compared result, a process for correcting an image geometric distortion of the projection data by using the corrected table, a process for detecting a location of a view field boundary of the detector from the distortion-corrected projection data, and a process for generating the projection data of a predetermined width from the detected location of the view field boundary through the effect of the extrapolation. The method operates to reconstruct a distribution of X-ray attenuation coefficients of the object from the extrapolated projection data.

Method and apparatus for X-ray computed tomography

An X-ray apparatus for collecting X-ray transmission data of a subject from a plurality of directions to generate an X-ray transmission image or X-ray CT image of the subject, which includes an X-ray generator for generating an X-ray, an X-ray detector for detecting a transmission X-ray after the X-ray generated by the X-ray generator is transmitted through the subject, a rotation unit for rotating an imaging unit including the X-ray generator and the X-ray detector around the subject, a data collector for converting an output signal of the X-ray detector to a digital signal and collecting the digital signal, a signal processor for subjecting data collected by the data collector to a signal processing operation, a display for displaying thereon as an image the data collected by the data collector and the data subjected by the signal processor to the signal processing operation, and a position change unit for moving a relative position of a rotation center of the imaging unit and the subject in a direction parallel to a rotation plane of the rotation, and wherein the imaging unit is rotated by the rotator around the subject and at the same time the relative position is changed by the position change unit in a direction parallel to the rotation plane to perform X-ray fluoroscopic or radiographic operation or CT scan.

Method for X-ray fluoroscopy or radiography, and X-ray apparatus

An X-ray computed tomography apparatus includes a controller for shifting an X-ray focal spot position of an X-ray source, a plurality of first temporary holding devices respectively connected to X-ray detector elements to temporarily hold measured values of X-ray intensity transmitted through an object to be incident on the X-ray detector elements, a switch device for switching over connection between the X-ray detector elements and the first temporary holding devices, a controller for controlling switchover of the switch device, a transfer device for transferring the measured values from the first temporary holding devices to an interpolation calculating device, an interpolation calculating device for performing interpolation calculations on the projection data to generate projection data equivalent to projection data measured by using a measuring system virtually having twice as many X-ray detector elements as the arranged X-ray detector elements, a memory for holding parameters used for calculations in the interpolation calculating device, and an image reconstructor for reconstructing a tomographic image on the basis of the projection data generated by interpolation calculating device.

Method and apparatus for x-ray computed tomography

In a magnetic field generation source measuring method and system for determining a magnetic field generation source in an object to be examined from a magnetic field in the interior of the object measured at the exterior of the object, the object is represented by a model in which the object is divided into a plurality of cells. The resistance values of each cell in x, y and z directions are determined from information concerning the electric conductivity of the interior of the object beforehand measured. Supposing the distribution of electromotive forces in the object as a current source, a return current generated in accordance with the electromotive force distribution in the object is determined by use of estimated values of the intensities of the current source in the x, y and z directions and the resistance values. A vector of the sum of a current of the current source and the return current is determined for all of the cells. The second power of the absolute value of a difference between the vector of the sum and a current vector determined from the magnetic field in the interior of the object measured at the exterior of the object is subjected to summation for all of the cells. The estimated values of the current source intensities, which minimize the summation, are determined as an electromotive force distribution in the object.

Method and system for determining electromotive force or impressed

An X-ray tomography scanner and an optical tomography scanner are combined to obtain an optical image indicting metabolism in the body. Optical projection data indicating light pulse transmissions in the body are compensated by using a light scattering coefficient distribution determined by an X-ray tomogram image discriminated into individual internal organs or tissues. The compensated projection are back-projected.

Method and apparatus for obtaining an image indicating metabolism in a

A data processing method for image reconstruction in an NMR apparatus for use in the medical field which reduces a computation quantity relating to data extrapolation when truncation artifacts are reduced by data extrapolation. The data processing method is utilized with an inspection apparatus including a magnetic field generation apparatus for generating each of a static magnetic field, gradient magnetic field and RF magnetic field, a signal detection device for detecting NMR signals from an inspection object, a computer for computing detection signals of the signal detection device and for outputting the result of computation by the computer, for obtaining an image by effecting inverse Fourier transform for a measurement signal row representing data of spatial frequency space. An evaluation value representing the magnitude of ringing which occurs because a measured spatial frequency domain is limited in the spatial frequency space is utilized for comparison with a threshold value and signals are extrapolated into spatial frequency domains which are located outside of a measured spatial frequency domain by use of coefficients computed from the signals of the measured spatial frequency domain only when the evaluation is greater than the threshold value so that an image in which the ringing thereof is corrected is obtained.

Data processing method to reduce truncation artifacts in nuclear

This invention relates to a data processing method for suppressing truncation artifacts mixed into two-dimensional images in nuclear magnetic resonance imaging. Two-dimensional measurement data arrays are obtained on a space frequency domain by the combination of phase encoding and a readout gradient magentic field, and a data position providing the greatest value of the one-dimensional data array constituting the two-dimensional measurement data array is obtained in the readout direction so as to estimate the origin of the space frequency axis in the readout direction. A high-pass filter using the estimated origin as a reference is applied to each one-dimensional data array, and data extrapolation is made for each one-dimensional data array to obtain a data array having an expanded region. Nuclear spin images are obtained by inverse Fourier transformation of these data arrays.

Data processing method in nuclear magnetic resonance measurement

A living body is replaced by a 3-D network. Admittance connected to lines forming the 3-D network is calculated. Position rt and magnitude qt=(jtx,jty,jtz) of a current dipole are assumed, and current sources jtx, jty and jtz are connected in parallel with lines coupled to a node. Node equations are formulated, and an admittance matrix Y is derived. An inverse matrix Y' of Y is calculated, and body surface potential generated by the current sources is calculated by using the inverse matrix Y'. Then, rt and qt minimizing cost function which is sum total of squares of differences between measured values of body surface potential and the above described calculated values for all measuring points are derived. Thereby potential distribution on the body surface can be calculated with due regard to the shape of the living body and conductivity distribution in the living body on the basis of the assumed current dipole. On the basis of measured data of potential distribution on the body surface, therefore, the position and magnitude of the current dipole can be estimated with high precision.

Method and apparatus for determining biocurrent distribution within

In an NMR spectroscopic analyzing method to which the simulated annealing method is applied, each amplitude, decay constant, resonant frequency, and phase of each spectrum component of an FID signal formed by a plurality of spectrum components are used as variables. A perturbation of an estimated value of each variable and a decision of whether the perturbation is accepted or rejected are performed in sequence based on a certain probability depending on a variation amount of a cost function produced from the estimated value. The probability of accepting the perturbation is gradually decreased in the process of repeating the perturbations to obtain estimated values which minimize the cost function.

NMR spectroscopic analyzing method

A process and an apparatus for measuring the biocurrent distribution call for initially assuming a number of multiple currents which is more than the number of isolated currents possibly existing in a living body and calculating the virtual magnetic field created by the assumed currents at actual measuring points. The estimated location and current vectors of said assumed currents are consecutively changed to decrease the difference between said virtual and actual magnetic fields so that the estimated location and current vectors of the assumed currents having the number corresponding to the true isolated currents substantially approximate the true values and the estimates of the other assumed currents approximate zero. This enables the biocurrent distribution to be exactly determined even when the number of isolated currents is not preliminarily known.

Process and apparatus for determining the biocurrent distribution of a

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Musashimurayama, Japan

Kensuke Sekihara