Abstract: A magnetic resonance (MR) imaging system for use in a medical procedure employs an open main magnet allowing access to a portion of a patient within an imaging volume, for producing a main magnetic field over the imaging volume; a set of open gradient coils which provide magnetic fields gradients over the imaging volume without restricting access to the imaging volume; a radiofrequency coil set for transmitting RF energy into the imaging volume to nutate nuclear spins within the imaging volume and receive an MR response signal from the nuclear spins; and a pointing device for indicating the position and orientation of a plane in which an image is to be acquired; an image control means for operating power supplies for the gradient coils and the RF coils to acquire an MR signal from the desired imaging plane; and a computation unit for constructing an image of the desired imaging plane.

Abstract: A thermal gradient zone melting technique is employed to migrate an array of metal buttons through a body of semiconductor material to form high aspect ratio P-N junctions therein. Semiconductor devices embodying such P-N junctions are suitable for employment in X-ray and infrared detection and imaging. Each button preferably has the configuration of an equilateral triangle and the array preferably has a hexagonal configuration.