Abstract: A method for producing dynamic images from a ghosted MR image is disclosed. The method includes acquiring an image data set including a time averaged image component and a ghost component and processing these components to produce a dynamic image. A motion monitoring system is not required as in conventional cine magnetic resonance imaging.

Abstract: An object is repeatedly excited by a 90-degree pulse and a plurality of spin echoes are obtained by a 180-degree pulse each time the excitation is repeated. The spin echoes are differently phase-encoded and the spin echoes thus generated are assigned to a substantial half portion of a raw image data space in a phase-encoding direction, the remaining substantial half of data being estimated from the data in that portion. The data covering the raw image data space are used to produce a corresponding image of the object.

Abstract: In an image reconstruction method for magnetic resonance imaging, an object to be imaged is reconstructed based on Fourier imaging. First, there specified is a spatial resolution smaller than a further spatial resolution under a Nyquist condition derived from the Nyquist theorem. Then, a transformation matrix according to the specified spatial resolution is calculated and an inverse transformation matrix of the calculated transformation matrix is calculated. Then, discrete magnetic resonance signals from the object is collected in accordance with the Fourier imaging. And, discrete oblique Fourier transformation(DOFT) using the inverse transformation matrix is performed on the collected discrete magnetic resonance signals.

Abstract: A magnetic resonance imaging magnet, gradient coil, and RF coil assembly is controlled by a workstation (40). The workstation (40) includes an operator input (46, 48) and a display system (58) including a video monitor (44) for displaying human-readable images reconstructed from magnetic resonance data. A scan/reconstruction rack (50) includes a scan processor (60) which controls scan parameters and a reconstruction processor (64) and associated hardware for reconstructing received magnetic resonance signals into the image representation. A scan sequencer (52) includes a master microcode board (90) which controls the scan sequencer in accordance with instructions received from the scan processor (60). The scan processor loads a series of codes describing gradient and RF waveform profiles into memories (130) of each of a plurality of profile channels (100, 102, 104, 106, 110, 112, 114).

Abstract: An RF coil system for MRI comprises a coil unit for producing an exciting RF magnetic field or receiving an MR signal. A distributed constant line is connected to the coil unit and is formed into a length less than n.multidot.(.lambda./4) (n is a positive integer of one or more), where .lambda. is an wavelength of the RF signal or MR signal. A lumped constant circuit is connected in series to the distributed constant line and virtually forming the length of n.multidot.(.lambda./4) in cooperation operatively with the distributed constant line.

Abstract: The magnetic field assembly of a magnetic resonance imaging device includes an annular superconducting magnet (10) which is mounted within a toroidal vacuum vessel (24). A cylindrical member (26) defines a central bore (12) through which the superconducting magnets generate a uniform, static magnetic field. A cylindrical, dielectric former (46) is mounted in the bore displaced by an annular gap (58) from the cylindrical member. A shimset (60) for shimming the uniformity of the magnetic field is mounted in the gap (58). A radio frequency coil (32) is mounted within the cylindrical member defining a patient receiving examination region. An RF shield (34) is mounted around the exterior peripheral surface of the former. Primary gradient coils (50, 52, 54) are mounted around and potted to the exterior of the dielectric former around the RF shield. Gradient shield or secondary coils (74, 76, 78) are potted around an exterior of the cylindrical member within the vacuum chamber.

Abstract: A magnetic resonance imaging apparatus based on a multi-echo imaging scheme and a multi-slice imaging scheme, is arranged to acquire all components of an echo signal which corresponds to low-frequency components in an image which is small in the absolute value of the phase encoding amount in a sufficient time to ensure a desired signal-to-noise ratio and to acquire echo signals which correspond to high-frequency components in the image which are large in the absolute value of the phase encoding amount in acquisition times shorter than that time to ensure a desired signal-to-noise ratio. The signal acquisition time can be reduced by shortening the time interval at which the 180.degree. pulses are generated. Due to reducing the signal acquisition time, parts of the echo signal in the read direction are not acquired. The components which have not been acquired are estimated by use of complex conjugate data of acquired data or mere 0 values for image reconstruction.

Abstract: For the purpose of three-dimensionally imaging a selected three-dimensional region of a subject under examination on the basis of magnetic resonance phenomena exhibited by hydrogen atomic nuclei, a magnetic resonance imaging apparatus comprises a unit for carrying out the contrast enhanced-fuirier acquiered steadystate technique (CE-FAST) extended to three dimensions, an image reconstruction unit for reconstructing a plurality of relatively thin slice images on the basis of echo signals from the three-dimensional region acquired by the unit, a weighting unit for weighting differently the plurality of relatively thin slice images obtained by the image reconstructing unit, an adding unit for adding slice images obtained by the weighting unit so as to produce a surface anatomy scan image of the three-dimensional region, and an image display unit for displaying the surface anatomy image obtained by the adding unit.

Abstract: A sequence controller (30) controls gradient pulse amplifiers (20) and a digital transmitter (24) to apply a conventional magnetic resonance imaging or spectroscopy sequence. One or more of the resonance excitation pulses includes a series of very small tip angle RF pulses (52, 70) applied in rapid succession substantially within the time interval of a normal RF excitation pulse (e.g. 10 msec.). A series of gradient pulses (58x, 58y, 72y, 72z) with linearly diminishing amplitudes and a repetition cycle that is an integer multiple of the duration of the very small tip angle RF pulses are applied such that an excitation trajectory in k-space follows a piecewise linear square spiral (FIG. 3 ) when gradients are applied along two axes or an octahedral spiral (FIG. 6 ) when a series of gradient pulses are applied along three axes. The subregion of resonance excitation is selectively shifted along one of the axes by applying a series of frequency offset pulses (66, 76) along one or more of the axes.

Abstract: An NMR system performs a 3DFT scan using a set of steady-state free precession (SSFP) pulse sequences. A contrast preparation pulse sequence precedes each series of SSFP pulse sequences employed to acquire one plane through the three-dimensional space, and it includes a spectrally selective RF inversion pulse tuned to fat or water. The sequence is repeated without any magnetization recovery delays until all the planes have been acquired.

Abstract: A resonator arrangement 10 serves for electron spin resonance spectroscopy. It comprises an upper carrier plate 30, a long center portion 32, 33, 40, 41 and a lower resonator section 45, 46, 47. In the area of the center portion 32, 33, 40, 41, there is provided at least one separating plane 50, 51 along which the resonator arrangement 10 can be divided into an upper part 52 and a lower part 52, it being possible to connect a plurality of different lower parts 53 to one and the same upper part 52.

Abstract: In magnetic resonance spectroscopy or imaging, e.g. n.m.r. or e.s.r., a method of localizing the region of a sample from which a resonance signal is obtained by modulating the component M.sub.z of magnetization in the B.sub.o direction according to position in the sample. This is achieved by flipping the spins away from the B.sub.o direction, applying a gradient magnetic field so that they lose or gain phase according to their position, refocussing the effects of any resonance offsets including chemical shifts and subsequently returning them to the B.sub.o direction whereupon M.sub.z depends on the phase lost or gained and thus the position. This may be repeated, possibly with different gradient fields or different phase pulses, to further localize the region before a resonance signal is finally detected. The contribution to the resonance signal varies with M.sub.z and so is localized to regions of greater M.sub.z.

Abstract: In a spin-echo magnetic resonance sequence a phase encoding gradient magnetic field (39) is applied after the 180.degree. rephasing pulse (32.sub.1). After detection of the spin-echo signal (33) the position dependent phases are compensated for by applying a further gradient magnetic field (39'), identical in size but opposite in sign. The phase difference (.phi..sub.32,1 -.phi..sub.31,1) between the RF-pulses (31.sub.1,32.sub.1) applied within a sequence is constant over the sequences. With no position dependent effects left at the end of a sequence the next sequence can be started immediately following the earlier one. A repetition time TR substantially shorter than the spin-spin relaxation time T.sub.2 is feasible, thereby developing a steady state of the magnetization. A TR of 50 ms or less can be obtained, as well as strong signals for long T.sub.2 substances and good T.sub.2 contrast. RF spoiling by changing phases of RF-pulses in subsequent sequences can destroy the T.sub.

Abstract: A method of verifying the integrity of the walls and seals of a sealed container is provided in which a low molecular weight gas is introduced into the interior of the container before the container is sealed. After sealing, the container either alone, or in batches with others, is placed into a chamber which is evacuated of gases to a pressure level below that interior of the container and is evacuated of the low molecular weight gas to a partial pressure below that which the gas has within the container. Subsequently the gas within the chamber is sensed to determine whether the rate of increase of the low molecular weight gas in the chamber exceeds a predetermined rate.

Abstract: A magnetic resource apparatus includes a mainly cylindrical RF coil (9) having a longitudinal directed central axis (33) and symmetry plane (35) which contains the central axis and a reference plane (37). The reference plane extends perpendicularly to the symmetry plane and also contains the central axis. The coil (9) has a number of rod conductors (39) which extend, parallel to the central axis (33), across a mainly cylindrical surface, and loop conductors (41) which extend around the central axis near the ends of the rod conductors, the length of the rod conductors (39) situated near the symmetry plane (35) being greater than that of the rod conductors situated near the reference plane (37).

Abstract: An RF pulse sequence (40, 42, 44) is applied to generate magnetic resonance in which a dipolar or bound spin system component of the magnetic resonance has a quadrature or 90.degree. phase offset from a Zeeman or free spin system component of the magnetic resonance. The resultant resonance signal is encoded with magnetic field gradients (50, 52, 54) and sampled during a dipolar spin system resonance echo (46). The process is repeated altering the relative phase of the three RF pulses (40', 42', 44') and of a digital radio frequency receiver (28) such that the sampled dipolar and Zeeman spin system components are again in quadrature, but 90.degree. offset in the opposite sense. The two resonance signals with their Zeeman components out of phase in the opposite sense are combined (64) such that the dipolar spin system components add and the Zeeman spin system components cancel.

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: To accomplish double-slice imaging by a nuclear magnetic resonance (NMR) imaging apparatus having an ordinary radio frequency magnetic field generator, two radio frequency magnetic field waveforms are used and slices are separated by subsequent calculation. More definitely, two slice portions are excited in a REAL direction by a COS waveform and are excited in an IMAG direction by a SIN waveform. When one of the slices is S1 with the other being S2, the signal SC when the COS waveform is used is S1+S2 while the signal SS when the SIN waveform is used is i.S1-i.S2. Therefore, the calculation for separating the slices proves SC+i.SS and SC-i.SS. The present invention can avoid the increase in the production cost of the apparatus due to the addition of hardwares.

Abstract: A new method of spatial localization in solids using the high off-resonance sensitivity of heteronuclear polarization transfer is presented in theory and experiment. Application in imaging and volume-selective spectroscopy are discussed and test experiments to this end are reported.

Abstract: In an NMR apparatus with a system of gradient coils for the production of a magnetic field gradient within a measurement volume (1) within a field coil, the transverse gradient coils are constructed unsymmetrically with respect to the z=0 plane dividing the measurement volume (1), however largely mirror symmetric to a x=0 or y=0 plane containing the z axis, and possess only two partial coils (20', 20''; 40', 40'') whose windings each exhibit the same winding direction. The axial gradient coils are cylindrically symmetric with respect to the z axis and totally unsymmetric with respect to the z=0 plane, and consist of at least two partial coils which are arranged on differing sides of z=0 plane, whereby the partial coils on one side largely exhibit the opposite winding direction than the coils on the other side, and whereby the number of coils with a particular winding direction is not equal to the number of coils with the opposite winding direction.