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: 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: 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: A fast spin echo NMR pulse sequence is modified to stabilize the magnitude of early NMR echo signals produced during each shot. Stabilization is accomplished by modifying the amplitude of the nutation angle produced in the spins by the corresponding RF refocusing pulses. This stabilization is relaxed for the first RF refocusing pulse so that its maximum RF power can be reduced relative to that of the other RF refocusing pulses and the bandwidth thereof increased to improve the slice select profile.

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: A method for obtaining a time sequence of nuclear magnetic resonance (NMR) tomograms of a certain sectional plane in a measuring volume for observation of variations with time of signal intensities from the sectional plane. The method where k data sets f.sup.'k =f.sub.1.sup.'k . . . f.sub.n.sup.'k are recorded for NMR-tomograms with a low spatial resolution characterized by a parameter n in a time sequence with a waiting time t.sub.w between the acquisition of each data set f.sup.'k. The method where, in terms of time before k data sets f.sup.'k, a data set f=f.sub.1 . . . f.sub.m is recorded for an NMR-tomogram of the same sectional plane with a high spatial resolution characterized by a parameter m (i.e. m>>n). Subsequently, by means of said primarily recorded data set, new data sets f.sup.'k are reconstructed from the successively recorded k data sets f.sup.'k for NMR-tomograms of the sectional plane with a high resolution in space and time.

Abstract: A process and an apparatus for leak testing a package. The method includes placing a sheet-like and airtight wrapper around a part of the package liable to leakage, e.g. a closing element. Applying a higher pressure to the outside than to the inside of the wrapper for causing the wrapper to fit closely around the part of the package and for hermetically sealing the wrapper from a part of the package outside the part to be tested. Sealing the measuring space between the enveloped part of the package and the wrapper pressed against it from the surrounding space by applying a measuring pressure in the closed measuring space which is different from the pressure then prevailing in the package, and for measuring the change of pressure in the closed measuring space for a determined measuring time.

Abstract: A permanent magnet for nuclear magnetic resonance imaging that provides an intense and highly homogeneous magnetic magnetic field is disclosed. The magnet is made up of a set of rings having two sub-sets of rings of permanently magnetized polygonal blocks, wherein the rings of a sub-set of rings are substantially concentric. In addition, the rings of the two sub-sets are complementary in terms of magnetization. Each ring of a sub-set is separated from its complementary ring by a space that is substantially the same for all pairs of complementary rings. The rings have a regular polygonal structure and are made up of blocks that also have regular polygonal shapes.

Abstract: The invention concerns a nuclear resonance well logging tool for insertion into a borehole with a permanent magnet which is magnetized perpendicularly to its axis and with means to transmit and to detect high frequency signals whereby the transmission and detection coils are orthogonal. The arrangement is configured for CW operation. The permanent magnet or the transmission and detection coil arrangement may rotate around the axis in order to modulate the nuclear resonance signals.

Abstract: A gradient magnetic field-generating coil assembly of MR imaging apparatus has a cylindrical core member for carrying coil windings that is divided into at least two cores at a central portion of a magnet bore, a gap is set up between the two cores at the central portion of the magnet bore and each core is provided at its opposite ends with parts for fixing it to the magnet, whereby the natural vibration frequency of the core can be deviated from an exciting force frequency and sound prevailing in the outside of the core and sound in the inside can be brought into interference with each other to thereby suppress vibration of the cores at the central portion of the magnet bore and reduce noise.

Abstract: A magnetic resonance blood flow imaging method employs a field-echo technique and a gapless multi-slice acquisition technique in which a selective excitation pulse with a flip angle of less than 90 degrees is utilized and a pulse repetition time is set shorter than usual. Imaging data are acquired from multiple slices of a subject under examination while the multiple slices are shifted in sequence in position. A cross-sectional image is reconstructed for each of the multiple slices. Images obtained by performing subtractions on plural images for the same slice are gathered to thereby produce an image of blood vessels of the subject under examination which contain at least two blood vessels which run substantially in parallel and are opposite to each other in the direction of blood flow therein.

Abstract: A surface coil holder for magnetic resonance imaging wherein the holder is provided with straps or tape for securing the holder to an MRI table and a body part of a patient. By preventing movement of the holder and the patient's body part during examination, image quality is maximized to thereby improve diagnostic accuracy. The holder is dimensioned for receiving a conventional 5" surface coil, and an insert is provided so that the holder can accommodate a conventional 3" surface coil.

Abstract: An NMR imaging method for the investigation of, in particular, solid-like substances which are exposed to a sequence of RF pulses in a homogeneous magnetic field, said sequence including an excitation pulse sequence and an additional pulse sequence, whereby, in one case, in at least one time interval between the end of the excitation pulse sequence and the beginning of the additional pulse sequence and/or in the time interval between the end of the additional pulse sequence and the appearance of an echo signal, the homogeneous magnetic field is at least temporarily overlapped with at least one gradient field and, in another case, at least one part of the sequence of RF pulses is overlapped with at least one RF gradient field, is characterized in that the additional pulse sequence includes a magic sandwich.

Abstract: A gas diffusion control assembly comprises a gas inlet; a restriction to the rate of flow of gas or vapor from the gas inlet in the form of a porous diffusion barrier extending across the gas inlet; and a polythene disc for causing all gas or vapor passing out of the inlet into the diffusion barrier to diffuse through part of the barrier along a path with a lateral outward component relative to the direction of action through the gas inlet.

Abstract: An apparatus for evaluating phase change of an emulsion comprises a sliding part having a sliding surface to which the emulsion is applied, a pushing part disposed at a fixed position and pushed against the sliding surface applied with the emulsion, and sensor means for measuring a force imparted to the pushing part in the sliding direction. Also disclosed is a method for evaluating phase change of an emulsion from changes in the force measured by the apparatus.

Abstract: A pulsed NMR analysis system and process comprising sample throughput system (P, LI, V1, V2) and user system controls (104) to establish digitized free induction decay curves (C), from which components functions are determined using non-linear regression techniques to correlate the curve components to the target nuclei.

Abstract: The magnetic resonance signal analyzer allows to generate a large variety of test signals including one or more frequencies. The test signals can be applied as electromagnetic fields or as currents to material under test. An electromagnetic or electrical response signal of the material under test be applied to the analyzer for processing to determine the response pattern of the material under test.

Abstract: A certain preselectable region of a sample, for example, a disc or a volume component, is selectively excited in that the transverse magnetization of the desired region is phase-coupled by spin locking, while the spin coherences in the remaining spatial region are destroyed by phase relaxation. The thickness of the desired disc or the dimensions of the desired volume component can be varied by adjusting the amplitude of the spinlock pulse while the magnetic field gradients are kept constant. Comparatively low magnetic field gradients can be used. Even with such low magnetic field gradients, good spatial resolution can be achieved while reducing the energy of the radio-frequency excitation. Because of the relatively low energy irradiation of the material being investigated, the process is especially suitable for in vivo applications.

Abstract: A fast spin echo NMR pulse sequence is modified to stabilize the magnitude of early NMR echo signals produced during each shot. Stabilization is accomplished by modifying the amplitude of the nutation angle produced in the spins by the corresponding RF refocusing pulses. When selective RF refocusing pulses are employed the slice is divided into subslices and the modifications are made separately to each subslice.