Abstract: A radio frequency (RF) coil array is used in resonance imaging and/or analysis of a subject located within a cylindrical space in which a magnetic field is operatively applied in an axial direction (z). The coil array comprises a plurality of coil elements (10, 11, 12, 13) angled relative to each other about the axis of the cylindrical space, each coil element having a pair of main conductors extending generally parallel to the direction of the magnetic field and located on diametrically opposite sides of the cylindrical space, and a pair of connection conductors connected between respective ends of the main conductors. Each coil element has its maximum sensitivity near the centre of the cylindrical space, so that the subject under study is located in a region of maximum sensitivity.

Abstract: Asymmetric radio frequency (RF) coils for magnetic resonance applications are provided. Also provided are time harmonic methods for designing such coils as well as symmetric coils. In addition, methods for converting complex current density functions into discrete capacitive and inductive elements are provided.

Abstract: A three-dimensional grid (10) is used as a phantom for mapping geometric distortion in magnetic resonance imaging (MRI) apparatus. This phantom provides an array of densely distributed control points in three-dimensional space. These points are each defined by three orthogonal planes. In the phantom image, the planes are determined by detecting boundary surfaces between portions of the phantom and its surrounding medium, enabling the positions of the control points to be measured to sub-voxel accuracy. The mapped distortion can then be used to automatically correct images produced by the MRI apparatus.

Abstract: Asymmetric radio frequency (RF) coils for magnetic resonance applications are provided. Also provided are time harmonic methods for designing such coils as well as symmetric coils. In addition, methods for converting complex current density functions into discrete capacitive and inductive elements are provided.

Abstract: Asymmetric radio frequency (RF) coils for magnetic resonance applications are provided. Also provided are time harmonic methods for designing such coils as well as symmetric coils. In addition, methods for converting complex current density functions into discrete capacitive and inductive elements are provided.

Abstract: Asymmetric radio frequency (RF) coils for magnetic resonance applications are provided. Also provided are time harmonic methods for designing such coils as well as symmetric coils. In addition, methods for converting complex current density functions into discrete capacitive and inductive elements are provided.

Abstract: Asymmetric zonal shim coils and shim sets for magnetic resonance applications are provided. Also provided are Fourier-series based methods for designing such coils as well as symmetric coils.

Abstract: An NMR probehead is proposed having a generally cylindrical casing extending along a probehead axis. The NMR probehead can be inserted into the room temperature bore of an NMR spectrometer magnet providing, in a measurement region, a homogeneous static magnetic field along the probehead axis. The NMR probehead comprises a cylindrical radio frequency (RF) resonator oriented along a resonator axis and generating essentially homogeneous RF magnetic fields transverse to the resonator axis. In accordance with the invention, the angle between the probehead axis and the resonator axis is different from 0.degree.. In this manner, the inclination of the resonator does not affect the useful RF magnetic field and the signal to noise ratio of the received NMR signal is independent of the inclination angle.

Abstract: A compact magnet is disclosed for high field, superconducting magnets for use in magnetic resonance spectroscopy. The magnet has at least a first and a second group of coils with the or each coil in the first group having wound to provide a negative current density with respect to the other coils. The first group acts to enable the overall length of the magnet to be reduced while maintaining a homogenous field over a central region of the magnet.

Abstract: The invention concerns a birdcage resonator used as a transmitter and/or receiver coil in an NMR apparatus. The resonator comprises two ring-shaped conductors each of which is interrupted along its outer periphery by capacitors, the ring-shaped conductors being connected together by axial conducting strips. A plurality of axial conducting strips have their ends located between each pair of peripherally neighbouring capacitors. It is preferred when RF energy is coupled in or out between two conducting strips and when the ring-shaped conductors are shielded by shielding rings in the direction towards the sample. The birdcage resonator in accordance with the invention exhibits an improved RF field homogeneity at higher Q compared to conventional birdcage resonators.