Abstract: A dual pointing device to be used in cooperation with an imaging apparatus, a tracking system, and an object to be imaged. The dual pointing device provides a means for tracking a point on in image in both the image's frame of reference and Euclidean absolute coordinates. This is accomplished by having two tracking systems follow the dual pointing device. Since the two tracking systems follow the same physical device, and since one tracking system operates in the image coordinates while the other tracking system operates in the absolute coordinates, the device makes it possible to effect automatic transformations between the two systems. More specifically, in the preferred embodiment of the dual pointing device, which is intended for use with a magnetic resonance imager, the absolute tracking system is based on infra-red reflectors on the device that are tracked by an infrared transponder.

Abstract: Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving RF coil disposed within the open region and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils is disposed outside of the open region. Another embodiment of the apparatus includes a single magnet assembly having a first surface and a second surface opposing the first surface, a transmitting RF coil having at least a portion thereof opposing the first surface, at least one receiving RF coil and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils opposes the second surface. In another embodiment the magnet assembly generates a permanent z-gradient magnetic field and therefore includes only X and Y gradient coils, at least one of which opposes the second surface.

Abstract: Adjustable hybrid magnetic apparatus for use in medical and other applications includes an electromagnet flux generator for generating a first magnetic field in an imaging volume, and permanent magnet assemblies for generating a second magnetic field superimposed on the first magnetic field for providing a substantially homogenous magnetic field having improved magnitude within the imaging volume. The permanent magnet assemblies may include a plurality of annular or disc like concentric magnets spaced-apart along their axis of symmetry. The electromagnet flux generator may include two electromagnet assemblies. The electromagnet assemblies and the permanent magnet assemblies may be static assemblies or may be movable and/or tiltable and/or movable and tiltable, for fine tuning of the magnetic field within the imaging volume. The hybrid magnetic apparatus may include a high magnetic permeability yoke for increasing the intensity of the magnetic field in the imaging volume of the hybrid magnetic apparatus.

Abstract: Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving RF coil disposed within the open region and X,Y and Z gradient coils. At least one of the X,Y and Z gradient coils is disposed outside of the open region. Another embodiment of the apparatus includes a single magnet assembly having a first surface and a second surface opposing the first surface, a transmitting RF coil having at least a portion thereof opposing the first surface, at least one receiving RF coil and X,Y and Z gradient coils. At least one of the X,Y and Z gradient coils opposes the second surface. In another embodiment the magnet assembly generates a permanent z-gradient magnetic field and therefore includes only X and Y gradient coils, at least one of which opposes the second surface.