Abstract: In a magnetic resonance imagining method, using an effect that a fluid flows out of a plane where it is selectively excited between the time of applying a 90.degree. radio frequency pulse and the time of applying of a 180.degree. radio frequency pulse, two, images are separately constructed from multiple echo signals which are sampled before applying the 180.degree. radio frequency pulse and multiple echo signals which are sampled after applying the 180.degree. radio frequency pulse. An image of the fluid flow and an image of a static part are separated from each other based on a difference between the two constructed images.

Abstract: This application describes a nuclear magnetic resonance inspection apparatus. In this apparatus, a nuclear magnetic resonance signal detected by a detection coil is wirelessly transmitted to a signal processing system. In another embodiment, the nuclear magnetic resonance signal is stored in a memory medium provided to the detection coil. This memory medium can be separated from the detection coil. The signal processing system reads out the nuclear magnetic resonance signal from the memory medium separated, and processes the signal.

Abstract: A magnetic resonance imaging method for obtaining an image of an object laid in a space in which a static magnetic field is applied, so as to substantially eliminate motional artifacts. The method includes sequentially measuring a plurality of magnetic resonance views with a plurality of encodings by repeating a measurement sequence of exciting nuclear spins in said object, applying a phase-encoding field gradient along a first direction with programmed time integral to encode the excited spins, and detecting the encoded spins in the presence of a readout field gradient along a second direction to generate a magnetic resonance view so that measurements of magnetic resonance views with at least low-order encoding are obtained during the repetition of the measurement sequence.

Abstract: In an inspection apparatus using nuclear magnetic resonance (NMR), a spatial distribution of homogeneity of a static magnetic field can be quickly measured even when a heterogeneous object is inspected, by measuring simultaneously phase data and a transverse relaxation time at the same spatial position of the heterogeneous object, removing the difference of a phase term due to a chemical shift by anticipating components at that position and obtaining only the phase data resulting from static magnetic field inhomogeneity.

Abstract: A nuclear magnetic resonance apparatus receives nuclear magnetic resonance signals from an object under test with an RF probe which is an array of coils, implements down-frequency conversion with frequency converters for the received signals in multiple channels such that the frequency bands of the converted signals do not virtually overlap, filters the converted signals with band pass filters each operating to cut off frequency bands of other channels, hybridizes the filtered signals of multiple channels to form a hybridized signal, and produces an image from the hybridized signal.

Abstract: This invention relates to a ultra-high speed nuclear magnetic resonance fluid imaging method for selectively reconstructing projected images of a fluid from an echo train generated by the use of a readout gradient magnetic field which inverses periodically. A pulse-like encoding gradient magnetic field is used in combination with a readout gradient magnetic field which inverses periodically, so as to generate an echo train containing alternately echoes whose phase change of magnetization due to a flow is emphasized and echoes whose phase change of magnetization due to the flow is corrected, and subjected sequentially to phase encoding. A data train containing only the echoes whose phase change of magnetization due to the flow is emphasized and a data train containing only the echoes whose phase change of magnetization due to the flow is corrected are formed from sampling data of these echoes, respectively, and two images are then obtained by subjecting them individually to two-dimensional Fourier transform.

Abstract: NMR signals of low concentration solutes are obtained with suppression of NMR signal of solvent by sequentially applying a first RF pulse sequence, a 180.degree. RF pulse and a second RF pulse sequence to an object. Each of the first and second RF pulse sequence includes equally spaced RF pulses which have flip angles in accordance with binominal coefficients. Phase errors due to inhomogeneity of a static magnetic field are cancelled through the two-time application of equally spaced RF pulse sequence.

Abstract: An MRI flow imaging method and apparatus wherein a width of a relevant region in a direction is set, in which fluid in a subject body flows, and a first 90.degree. radio frequency pulse is applied thereto to excite selectively a relevant region; a gradient magnetic field is applied thereto in a direction, in which it is desired to project the fluid, after an application of a first 90.degree. radio frequency pulse so that a magnetization signal in a projection direction is zero, a second radio frequency pulse is applied to a relevant region to excite the relevant region selectively, after new fluid has poured in the relevant region, an echo signal is measured by applying an encoding gradient magnetic field and a reading out gradient magnetic field in a form of a flow sensitive pulse capable of detecting an echo signal from the fluid, and an echo signal is processed to obtain a two-dimensional image of the fluid.

Abstract: A multi-echo NMR imaging method of obtaining images separated from each other with respect to two kinds of chemical shifts, typically, a fat image and a water image, includes performing the measurement of an object to be examined through a multi-echo sequence in which phase differences of .theta..sub.1 .noteq.n.pi. and .theta..sub.2 =2n.pi. (n=.+-.1, .+-.2, ---) are respectively produced for first and second echoes between two kinds of spins to be separated from each other, deriving first and second complex images of the object from the first and second echoes, respectively, performing the measurement of a phantom exhibiting one of the chemical shifts through the multi-echo sequence and deriving third and fourth complex images of the phantom, eliminating phase errors due to a static magnetic field inhomogeneity from the first and second images using phase data of the third and fourth images respectively, and eliminating phase error due to a magnetic permeability distribution to the object.

Abstract: In a nuclear magnetic resonance imaging apparatus including a first probe circuit for detecting magnetic flux in a first direction and a second probe circuit for detecting magnetic flux in a direction perpendicular to the first direction, the arm angle of conductor arms to form the first probe circuit and the arm angle of conductor arms to form the second probe circuit are different from each other.

Abstract: In an imaging apparatus using the nuclear magnetic resonance, a solenoid coil and a slot-resonator coil are combined with each other so as to constitute a quadrature-phase detection probe. In order to operate the slot-resonator coil at low frequency, inductance is added to the slot-resonator coil. Further in order to cut the coupling between a transmitting coil and a receiving coil in a cross coil system, a capacitor together with the added inductance to form a resonant circuit is connected in parallel to the inductance. A favorable probe can be obtained in a vertical-magnetic field type imaging apparatus.

Abstract: A testing method and apparatus by use of nuclear magnetic resonance measure, at timings influenced and not influenced from chemical shift, nuclear magnetic resonance signals taken from a sample to be tested at least one of whose values of permeability and chemical shift is known and a reference sample both of whose values of permeability and chemical shift and their spatial distribution are uniform thereby to acquire four items of image vector information. Further, the testing method and apparatus take phase differences between the items of image vector information to separately extract the phase component influenced by the permeability distribution and the phase component influenced from the chemical shift.

Abstract: A three-dimensional NMR imaging method using phase encoding field gradients along two direction is disclosed. The measurement of an NMR signal is repeated in such a manner that among all combinations of a plurality of magnitudes of gradient prepared for the phase encoding field gradient along one of the two directions and a plurality of magnitudes of gradient prepared for the phase encoding field gradient along the other direction, combinations in which the magnitude of the phase encoding field gradient along the one direction is not larger than a predetermined value, are selected preceding the remaining combinations. A first image reconstruction processing is performed for data trains acquired on the basis of the precedently selected combinations, thereby obtaining a crude image. The crude image is displayed to confirm whether the location of measurement is proper or not.

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: A cracking furnace for thermal cracking of hydrocarbon feedstocks has a central burner provided vertically at the center of the ceiling of a combustion chamber, side burners provided vertically at both sides of the central burner, and reaction tubes vertically arranged between the central burner and resepctive side burners. The reaction tubes are arranged in rows along the longitudinal direction of the chamber and form arch bands at the lower part of the combustion chamber. A combustion gas-inducting duct is provided at the bottom of the chamber, a quenching heat exchanger is provided at the upper part of the chamber, and a reaction tube exit header is provided for connecting a plurality of exits of the reaction tubes to the quenching heat exchanger.

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: 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: In a signal detecting circuit of, for example, an NMR apparatus, a signal transmission path transmits an AC magnetic flux signal to be superposed on a DC magnetic field whose strength does not change with time during a period of signal detection. The signal transmission path comprises a superconducting closed loop including a receiving coil receiving the AC magnetic flux signal, an input coil applying the received AC magnetic flux signal as an input to a flux meter, and a variable resistor replacing part of the superconducting closed loop and having its resistance value changed in relation to a change in the strength of the DC magnetic field.

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.