Abstract: A material having magnetic permeability at r.f. frequency, for example a microstructured magnetic material has a magnetic permeability of negative value but unity magnitude over a particular r.f. frequency range. The singularity in the flux pattern has the result that magnetic resonant disturbances in a plane C,E normal to the line C,D are focussed into a plane D,F also normal to the line C,D and vice versa. This is particularly applicable to magnetic resonance apparatus, since the material can be used to transfer the r.f. magnetic flux distribution in a target region in a patient, for example at C,E to D,F where the flux may be directly measured by receive coils. Equally, transmit coils may generate flux to be focussed into the target region by the material. Magnetic resonance apparatus may be constructed which does not require gradient coils, and r.f. hypothermia may be carried out in a focussed way, minimising damage to surrounding tissue.

Abstract: A material having magnetic permeability at r.f. frequency, for example a microstructured magnetic material has a magnetic permeability of negative value but unity magnitude over a particular r.f. frequency range. The singularity in the flux pattern has the result that magnetic resonant disturbances in a plane C,E normal to the line C,D are focussed into a plane D,F also normal to the line C,D and vice versa. This is particularly applicable to magnetic resonance apparatus, since the material can be used to transfer the r.f. magnetic flux distribution in a target region in a patient, for example at C,E to D,F where the flux may be directly measured by receive coils. Equally, transmit coils may generate flux to be focussed into the target region by the material. Magnetic resonance apparatus may be constructed which does not require gradient coils, and r.f. hypothermia may be carried out in a focussed way, minimising damage to surrounding tissue.

Abstract: In an endoscope, the tip which contains passages for viewing and light guiding is made of plastics material, for MR compatibility purposes, and an r.f. receive coil of the endoscope is provided with a fiducial having its own r.f. receive coil, to make it possible to track movement of the r.f. receive coil.

Abstract: A magnetic resonance imaging probe includes a dipole including a first arm and a second arm. The second arm includes an elongate loop coil. In one embodiment, the loop coil is an open coil. In another embodiment, the coil is a twisted coil. The first and second arms are electrically connected to provide a dipole output. The second arm is electrically connected to a loop output.

Abstract: An RF coil structure for intra-cavity use includes a pair of conductors (7, 8) separated by a support such as a web (9) which come together at positions separated along the length of the coil structure such as (A, B). Previous coils have included two parallel conductors. If the conductors (7) and (8) were parallel, while the structure could be flexed transverse to the plane of the web (9) about the arrow (10), it could not be flexed in the plane of the web (9) about arrows (12, 13). Because the conductors come together at points (A) and (B), it can be so flexed. A second coil may be provided including conductors (4, 5) and flexing about the same points as for the first coil is still possible because the points of closest approach for one pair come between those for the other pair.

Abstract: A method and coil arrangement for use in magnetic resonance imaging facilitates the examination of a localized region of the body. A plurality of substantially identical saddle coils are disposed about a former. The coils, which define a generally cylindrical volume, overlap one another in a circumferential direction. In one embodiment, a generally planar rectangular coil intersects the cylindrical volume. The method and coil arrangement are particularly well suited to imaging a region adjacent but outside the cylindrical volume. The coil arrangement is also well suited to insertion within the body, especially the rectum.

Abstract: An MR compatible endoscope 1 has associated MR saddle coil 10 mounted on a removeable former 9. The tip 2 of the endoscope has the usual service channels for imaging. The coil 10 provides an additional MR signal. To avoid the need to plug the coil 10 in, it is inductively couples to a pick-up coil 13 and, to enable this to be removable as will from the endoscope, this may be located in one of the service channels 7 of the endoscope. The removable nature of the coil permits easy repair and, more importantly, a range of coils to be fitted to the endoscope to accommodate different magnetic field strengths.