Abstract: Disclosed is an NMR gated imaging apparatus in which an ultrasonic pulse signal is repeatedly transmitted toward the heart of a human body from an ultrasonic transducer to detect the position of the heart on the basis of the time of detection of a peak of an echo signal, and excitation and measurement of an NMR signal are executed only when a peak detector generates a detection output signal having a level included in a predetermined range. Thus, the NMR signal is repeatedly measured according to a programmable phase encoding amount at a limited phase of gated imaging.

Abstract: An RF magnetic flux measuring circuit uses a SQUID fluxmeter of which the input and output characteristics establish a periodic function, and in which a pick-up coil for picking up desired RF magnetic flux and an input coil of the SQUID fluxmeter are connected to form a closed loop which is a superconducting loop for transferring the magnetic flux to the SQUID. There is also provided an inductance adjusting device which adjusts the inductance of the superconducting loop to limit the magnetic flux that crosses the SQUID fluxmeter within a range of a single-valued function in said input and output characteristics.

Abstract: A toner for electrophotography produced by polymerizing a monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder, followed by coagulation is excellent in properties, particularly in cleaning properties, charge stability and caking resistance.

Abstract: A field gradient generator in an NMR imaging apparatus comprises three sets of field gradient generating coils for respectively generating field gradients in three orthogonal directions in a space to be observed. Each set of coils includes a plurality of unit coils through which individual currents respectively flow. There are prepared a plurality of unit drivers which are for exclusive uses of the respective unit coils or are connected arbitrarily to each unit coil. Thereby, the lowering of an allowable operating voltage is implemented by use of a parallel operation of the unit drivers.

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: Latex particles are sensitized with Immunoglobulin G obtained from the antiserum collected from a laboratory animal which has been immunized with a toxin extracted from pathogenic enterobacterium. The IgG-sensitized latex is useful for diagnosis of diseases caused by pathogenic enterobacteria.

Abstract: There is provided a probe to detect a nuclear magnetic resonance signal in which each of a plurality of arms forming a current path of an Alderman-Grant type coil is divided into two conductor plates, the two conductor plates are connected by an inductor, and a resonance frequency is reduced by increasing the inductance of the current path.

Abstract: A high-frequency coil of the type of slot resonator in which outer conductors that have wing portions at both ends thereof and that are divided, are formed on the cylindrical surface, and ring-like inner conductors are formed on the inside of the wing portions. The wing portions have a width different from the width of the inner conductors. The self resonance frequency of the coil is adjusted by adjusting the width which is smaller than the other width. Further, the neighboring tips of the wing portions are opposed to each other via an air gap. The self resonance frequency is also adjusted depending upon the position of the dielectric plate inserted in the gap.

Abstract: An NMR imaging method for obtaining a tomographic image of an object through two-dimensional Fourier transformation imaging. After a whole image of a predetermined slice is displayed, a given field of view having a given size and located at a given position in the image is designated. On the basis of data derived from this designation, setting values for magnetic field generators and a signal detector are arithmetically determined for limiting the region in which the NMR signal is generated and the region to be imaged, whereby local imaging of the aforementioned field of view is conducted with high resolution. Further, division of an image resulting from the imaging operation is automatically corrected by exchanging positionally the divided image blocks with each other.

Abstract: A quadrature probe for nuclear magnetic resonance includes two sets of coils which are combined with an angle of 90.degree. therebetween. Four pieces of outer conductors and two pieces of ring-shaped inner conductors are capacitively coupled to each other through an insulator or an air gap. In the outer conductor(s) in at least one of a set of outer conductors disposed at positions symmetrical with respect to each other so as to form a first coil and a set of outer conductors disposed at positions symmetrical with respect to each other so as to form a second coil, a conductor member(s) for adjustment is attached in parallel to the arm portion(s) in that outer conductor(s) of that set. Alternatively, the arm portion(s) itself in that set is slidably attached to the wing portions in that set.

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 of finding error distribution in the static magnetic field and distribution of deviations from straight lines in the gradient magnetic fields of an NMR imaging apparatus which employs the applied spin-warp method. A phantom whose shape has been known is measured in the read-out gradient magnetic fields having different polarities to obtain two spin density distribution images. The two images are then compared with the shape of said phantom to measure the distortion distributions of the images. Error in the static magnetic field and deviations of the gradient magnetic fields from the straight lines are analyzed from the distortion distributions. From the thus obtained error distribution, furthermore, distortion induced in imaging the object is estimated, and the distortion contained in the image that is reconstructed from the spin density of the object by the spin-warp method is corrected using the thus estimated value.

Abstract: Disclosed in a nuclear magnetic resonance (NMR) based inspection apparatus using an SQUID flux meter for detecting a small NMR signal, in which a receiving coil for receiving the NMR signal from an object is connected to a mixer, which mixes a reference high-frequency signal with the NMR signal so that the NMR signal is reduced to a low-frequency signal having a differential component of frequencies of both signals, and the low-frequency signal is applied to the input coil of the SQUID flux meter so that it is converted into a voltage signal. The mixer circuit includes Schottky diodes operative at a liquid helium temperature or Josephson junctions, and the portions of apparatus from the reception coil up to the SQUID flux meter are operated in a superconductive state at a liquid helium temperature.

Abstract: An NMR imaging method is disclosed in which an object is measured in accordance with a pulse sequence capable of expressing a difference between two of a plurality of chemical shifts by a phase difference in a signal, that is, a pulse sequence 90.degree.-.tau..sub.a -180.degree.-.tau..sub.b -spin echo (where .tau..sub.a .noteq..tau..sub.b) to obtain spin distribution data, a histogram with respect to the phase of the spin distribution data is formed to regard a phase corresponding to that one of a plurality of peaks of the histogram which exists at one end of the histogram, as a position-independent offset phase which is contained in the spin distribution data and is peculiar to an NMR imaging apparatus, and the spin distribution data is corrected using the offset value thus obtained, to extract spin density distribution data for each of the chemical shifts from the corrected spin distribution data.

Abstract: Method for measuring the time dependence of an oscillating field gradient and representatively its integral function with respect to time for imaging method using the field gradient such as rapid chemical shift imaging method echo planar method, etc. A uniform specimen is placed within a coil of an NMR device, in which nuclear spins are excited; a phase encoding field gradient is applied thereto; and signals are sampled under application of the field gradient to be measured. These steps are repeated and an integral function of the field gradient with respect to time is obtained by using the peak position in the series of data obtained by this repetition.

Abstract: An Alderman high-frequency coil used for generating or detecting a high-frequency magnetic field in an NMR apparatus comprises two ring-shaped inner conductors aligned coaxially with a spacing being made therebetween and two outer conductors disposed to surround the inner conductors. The outer conductors are each split along the current path to form a 4-piece outer conductor.

Abstract: In an imaging method called spin warp method in which a measuring sequence inclusive of nuclear spin excitation, application of phase-encoding gradient field, and measurement of NMR signals under the application of read-out gradient field, is repeated while changing the phase-encoding amount, and a data train thus obtained is subjected to the two-dimensional inverse Fourier transformation to reconstruct a magnetization distribution image of an object, wherein an NMR imaging method is characterized in that measurement of NMR signals is repeated a plural number of times for a particular phase-encoding amount only among many phase-encoding amounts, a plurality of NMR signals thus obtained are added up together and are averaged, and the data obtained by the addition and averaging is subjected to the two-dimensional inverse Fourier transformation.

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.

Abstract: An NMR imaging method using a rotating field gradient is disclosed in which transverse magnetization is prepared in a portion of an object to be inspected, by the 90.degree.-180.degree. RF pulse excitation, a rotating field gradient is generated to perform a sampling operation for an output signal in a state that the position of signal in a phase space is revolved, the intensity or rotational speed of the rotating field gradient is varied stepwise or continuously to obtain data arranged on concentric circles or a spiral in the phase space, and the data thus obtained undergoes Fourier transformation in each of a plurality of radial directions or two-dimensional Fourier transformation, to form an image of spin distribution.