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: In magnetic resonance imaging apparatus employing magnetic gradient fields in a phase-encode and in a read-out direction for spatially encoding excited MR active nuclei in a region of interest of a patient, in which a reduced number of readings in the read-out direction is taken, thereby creating an aliased reduced field of view image, at least two r.f. receive coils are used together with sensitivity information concerning those coils in order to unfold the aliased image to produce a full image while taking advantage of the reduced time of collection of data. In accordance with the invention, sensitivity information is collected at a lower resolution than that at which the image information is collected.

Abstract: In magnetic resonance imaging apparatus employing magnetic gradient fields in a phase-encode direction for spatially encoding excited MR active nuclei in a region of interest of a patient, in which a reduced number of readings in the phase-encode direction is taken, thereby creating an aliased reduced field of view image, a pair of r.f. receive coils is used together with sensitivity information concerning those coils in order to unfold the aliased image to produce a full image while taking advantage of the reduced time of collection of data. In accordance with the invention, the phase sensitivity pattern of each coil over the region of interest is different from that of the other coil.