Abstract: 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 V1 specifying 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 V2 defined coarser than the voxel division V1; and reconstructing, by using the Gram matrix, a direction and strength of a current of a signal source in the voxel division V1.

Abstract: 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 V1 specifying 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 V2 defined coarser than the voxel division V1; and reconstructing, by using the Gram matrix, a direction and strength of a current of a signal source in the voxel division V1.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 par

Abstract: 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 th

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method wherein the requirement for the amplitude of the oscillating gradient magnetic field is relaxed by reconstructing an image while using simultaneously echoes S.sub.p (k.sub.x, y) produced in the case where the positive oscillating gradient magnetic field is applied to the object to be tested and echoes S.sub.N (k.sub.x, y) produced in the case where the negative is applied thereto, i.e. by using data points on segments of a trajectory of data points ascending from left to right in the spatial frequency domain and those on segments of a trajectory of data points ascending from right to left. That is, the image M(x, y) is obtained by Fourier-transforming at first the echoes S.sub.p (k.sub.x, k.sub.y) and S.sub.N (k.sub.x, k.sub.y) with respect to k.sub.y, multiplying complex numbers a.sub.1 and a.sub.2 to g.sub.p (k.sub.x, y) and g.sub.N (k.sub.x, y) obtained by this transformation; adding the results thus obtained, i.e. forming g(k.sub.x, y)=a.sub.1 g.sub.p (k.sub.x, y)+a.sub.2 g.sub.N (k.sub.

Abstract: An NMR spectroscopic imaging method of obtaining separate spin distribution images for respective spectral components of the spectrum of an NMR signal caused by the chemical shift of nuclides of interest in an object includes providing for a transversal magnetization signal of the object placed in a static magnetic field. A position of the signal in a phase domain is translated in a K-space from the origin thereof. Further, the signal is sampled while rotating a position of the signal in the K-space plural times on a certain circle in the K-space by applying a rotating field gradient, thereby to obtain a group of signal data. Signal data trains each of which is composed of signal data present at the same position on the K-space in the signal data group obtained by the sampling during the plural signal rotations, is subjected to Fourier transformations, respectively, thereby effecting a spectral analysis of the NMR signal.

Abstract: A method for providing spin density distribution images of an object, discriminated with respect to plural chemical shifts. This method is performed by repeating a measurement sequence in a spin warp imaging method, of the spin data plural times, with a time difference .DELTA..tau. between a time interval .tau..sub.1 from spin excitation to a 180.degree. RF pulse and a time interval .tau..sub.2 from the 180.degree. RF pulse to a peak of a spin echo, altering .DELTA..tau. in the ways corresponding the number of chemical shifts to be discriminated from one another, subjecting the respective spin data to two-dimensional Fourier transform to provide plural sets of spin data for respective coordinates in a spatial domain, and solving simultaneous equations of the sets of spin data to provide spin densities corresponding to the respective chemical shifts.

Abstract: In imaging methods represented by the echo-planar method, i.e., in a method including a step of measuring the spin echos while applying a fixed gradient magnetic field to an object and applying a gradient field G.sub.Y periodically inverted in sense to the object and a step of obtaining the spin distribution image in the spatial domain by applying two-dimensional Fourier transform to the measured data, measurement is repeated a plurality of times while altering the phase of the applied waveform of G.sub.X, and the spin density image is derived by applying two-dimensional Fourier transform to a plurality of sets of data groups thus obtained.