Abstract: An apparatus is disclosed for conducting nuclear magnetic resonance experiments on an extremity of a big animal, in particular a horse. The apparatus includes a magnet assembly for receiving the extremity. A housing is provided adapted to the shape of the big animal. The housing incorporates a protrusion for receiving the extremity. The protrusion is adapted to be inserted into the magnetic assembly. A radio frequency (rf) assembly is provided for irradiating rf signals on the extremity and/or for receiving nuclear magnetic resonance signals from the extremity. The rf assembly is adapted to be attached to the protrusion.

Abstract: An MR tomograph, the magnet system (2) and gradient system of which permit access to the investigation volume along at least two essentially orthogonal axes, comprises a positioning system for the exact determination of the position of a manually guided manipulator (12) relative to the measuring object (6) which is investigated by means of imaging MR measurement and located in the investigation volume (3) of the MR tomograph (1); with a mounting frame (11) with which the manipulator (12) is connected via movable mechanics comprising a measuring means through which the respective spatial position of the manipulator (12) relative to the mounting frame (11) can be determined, wherein the measuring means of the movable mechanics does not utilize any MR signals and wherein the measured position of the manipulator (12) is displayed on the MR image. In this way, minimum-invasive operations, e.g.

Abstract: An electromagnet for producing the constant magnetic field required for use in NMR tomography consists of a cylindrical field coil and a stable cylindrical shell made of iron encompassing and simultaneously supporting the coil. The field coil may comprise constituent coils, including error coils, and is capable of producing an at least approximately homogeneous magnetic field within the space defined by the field coil for receiving the object to be examined. Due to the strictly symmetric geometry of the coil assembly, the homogeneity of the magnetic field is not adversely affected by temperature fluctuations, even if the dimensions of the apparatus are such that the coil will admit a human body.