Magnetostatic field generator null for magnetic resonance imaging device

摘要

PURPOSE: To provide a static magnetic field generator for a magnetic resonance imaging apparatus equipped with a means adjusting the intensity and uniformity of a magnetic field. CONSTITUTION: Shield plates 6, 6 composed of a superconductor for adjusting the intensity and uniformity of a static magnetic field and magnetic poles 7, 7 are, arranged in a measuring space in which a subject is placed. These superconductors suppress the leakage of the magnetic fluxes formed by magnets 1, 1 from an air gap 2 by the Meissner effect thereof and control the direction of a line of magnetic force to obtain a static magnetic field having sufficient intensity and high uniformity. Therefore, even in an open type magnetic resonance imaging apparatus wide in air gap, the high uniformity of a static magnetic field can be obtained without using a large magnet and an accurate MRI image can be obtained. Since it is unnecessary to use a magnetic pole such as iron, a generation problem of an eddy current is eliminated and the delay of the rising of an inclined magnetic field coil caused by an eddy current is eliminated and an imaging time can be shortened.