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 coil circuit comprising a multi-mode resonant gradient or RF coil circuits for imaging and spectroscopy in Nuclear Magnetic Resonance systems.

Abstract: Coherence transformation selectivity is improved by using combinations of homogeneous RF pulses and "radial" RF pulses that have a uniform RF field strength throughout the sample, but whose phase (relative to the detection coil phase) has a spatial dependence such that all possible phase differences are equally represented throughout the sample. The use of radial pulses allows the spin coherences in the sample to evolve in spatial waves and the observation, or suppression, of a given coherence can be selected by using a receiver coil which has a predetermined symmetry relative to the symmetry of the spatial wave.

Abstract: A first sectional image corresponding to a first section of an object to be examined is displayed on a screen of a display device. A position of a first line on the first sectional image is designated. First data corresponding to a distance between the first line and a center of the screen is obtained. A second sectional image corresponding to a second section of the object is displayed on the screen. The second section crosses the first section on a line on the first section corresponding to the position of the first line. A position of a second line on the second sectional image is designated. A position of a first point contained in the position of the second line is designated. Second data corresponding to a component in the direction of the second line is obtained. The component is a component of the distance between the first point and the center of the screen.

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 NMR probe is designed to generate both a homogeneous RF field over the sample volume and, alternatively, a "radial" field comprising two orthogonal gradient fields generated simultaneously in the transverse plane or a linear gradient field. The homogeneous field is generated by means of a known homogeneous coil construction, such as a Helmholtz coil or modified Helmholtz coil. The radial field can be generated by means of an inverted Helmholtz coil, either modified or unmodified, and the linear field can be generated by a Golay type coil, which coils are positioned coaxially with the homogeneous coil. The two coils are connected in parallel to the RF signal generator and switching can be accomplished either by means of an active switch or by detuning one of the coil resonant circuits when the other coil is in use.

Abstract: The harmonic relationship of certain chemical species is exploited to produce an MRI image of a single chemical species in the presence of at least two other chemical species with the acquisition of as few as two NMR images. If the chemical shift frequencies at a particular polarizing field strength can be approximated as the ratio of two odd integers, an evolution time can be chosen for the images acquired to cancel the contributions of two of the species in one image with a corresponding contribution in the other image. A image of the uncanceled species or of the cancelled species alone may be generated. A third image may be used to correct for inhomogeneities in the polarizing B.sub.0 field.

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 resonant array for NMR for use at high frequencies, the array comprising two identical end structures and a plurality of continuous rods joining the identical end structures to comprise a plurality of or electrical circuit sections, the continuous rods being of electrically conductive material; the continuous rods thereby supporting the end structures a predetermined distance apart.

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: A known magnetic resonance device (1) operates with a coil array (c1 to cn) which serves as a detection coil whereby magnetic resonance signals are detected so as to form partial images of a sub-volume of an object (5) to be measured. A signal processing unit (9) forms an overall image from the partial images. Because the known device utilizes separate detection and signal acquisition channels, it is comparatively expensive and complex. In accordance with the invention, a simpler and less expensive magnetic resonance device (1) is obtained in that the device comprises a signal combination device (28) which shifts frequency ranges (s1 to sn) of individual coil elements in the coil array in respect of frequency and which forms, from the shifted frequency ranges (o1 to on) a sum signal (sm) in which the frequency ranges are separated from one another.

Abstract: A local antenna for transmitting and/or receiving radio frequency signals in a nuclear magnetic resonance imaging apparatus includes first and second sub-antennas which are axially spaced from each other. The sub-antennas each are composed of at least one conductor turn. An electrical series circuit is formed of the first sub-antenna, a capacitive element for shortening the path length effective for the radio frequency signal and of the second sub-antenna. The two sub-antennas have the same winding direction. A capacitor is connected in parallel with the series circuit. The respective capacitance values of the series capacitive element and the parallel capacitor are approximately the same. For constructing a local antenna system especially suitable for mammography, two such local antennas are arranged side-by-side and are electrically connected in parallel. The series capacitive elements of the two local antennas face each other.

Abstract: In order to simplify the process of plotting a pulse sequence controlling the course of an MR experiment, for example an NMR tomographic investigation, by which the excitation of an RF pulse bringing about transverse magnetization, the switching on and off of field gradients acting in different directions, superposed on a constant magnetic field, as well as the acquisition times, it is proposed to generate this pulse sequence by modification of standard pulse sequences and/or by composition from standard pulses. These pulses are offered on a picture screen (22) as simple symbols (42-49), icons, or brief designations for standard pulse sequences (36-41). By clicking-on of the offering fields, for example by means of a mouse (51), these elements can be copied on time axes (58) allocated to them and attached at the suitable release time point onto these axes. The pulse sequence thus determined is stored on-line.

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: 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 composite RF pulse for NMR experiments is created by applying to a sample a radial pulse followed by a .pi. homogeneous pulse. The radial pulse has a uniform RF field strength throughout the sample and a phase relative to the detection coil phase with a spatial dependence such that all possible phase differences are equally represented throughout the sample. The composite pulse converts the radial RF pulse into a spatially-varying z rotation. The creation of a spatially-varying composite z pulse based on a radial pulse allows for a simple and direct application of a radial pulse in a manner analogous to many known B.sub.0 gradient NMR experiments (such as multiple-quantum filters, quadrature detection, and solvent suppression).

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.

Abstract: A nuclear magnetic resonance imaging for measuring a speed of a flowing target object, capable of determining the speed of the flowing target object accurately, even for the high speed flowing target object. Timings for an application of a pre-saturation pulse to a saturation plane producing a saturated portion within the flowing target object and an execution of an imaging pulse sequence to collect NMR signals from a desired imaging region containing a saturation plane and the saturated portion are controlled to realize a single slice multi-phase pulse sequence, at each phase of which an application of the pre-saturation pulse is followed by an execution of the desired imaging pulse sequence.

Abstract: A combined fermenter and measuring tube for NMR throughflow spectroscopy on cell suspensions in which the measurement tube has a capacity of 3 to 20 ml in the measuring zone of the magnet and a fermenter is a premagnetization reservoir of greater cross section of a capacity of at least 100 ml in the repolarization range. A liquid circulator is provided to provide a throughflow rate of 5 to 250 ml/s in the measuring tube.

Abstract: Apparatus for mapping a static magnetic field is provided. An NMR-suitable sample or array of samples is positioned in a magnetic field probe adapted to generate an alternating magnetic field and for measuring an induced signal from the sample as a result of being exposed to the alternating magnetic field. The induced signal from the sample is measured at discrete points along a helispherical or heliellipsoidal path located within the static magnetic field. Shim coils can be positioned within the static magnetic field and the current directed to the coils can be controlled as a result of the field mapping results in order to homogenize the static magnetic field. Ferromagnetic elements can be inserted in appropriate locations instead of, or in addition to, the shim coils. One such probe or any array of such probes are mounted on an actuator mechanism, which mechanism moves the probe or array of probes along a helispherical or heliellipsoidal path located within the static magnetic field.