Magnetic resonance imaging apparatus and method

Abstract

The invention relates to a novel magnetic resonance imaging apparatus. The nuclei, protons or the paramagnetic electrons of an imaged object are cyclically polarized during a period of about one second with a permanent magnet which is then quickly shifted away from the imaged object in a permanent magnet carrier tube, so that the field of the permanent magnet would not have an interfering effect on the immediately following signal-collection for MRI-imaging. The permanent magnet can be manipulated or shifted back and forth in the tube either magnetically, pneumatically, hydraulically or mechanically. The apparatus also includes another permanent magnet or a resistive magnet coil couple, which is located in the tube near the opposite end of the tube, and which generates a homogeneous magnetic field within the imaged area. The apparatus includes a gradient coil system for generating a time-dependent magnetic field gradient necessary for imaging, as well as a coil system for producing an electromagnetic radio-frequency excitation signal to be linked with the nuclei or paramagnetic electrons of an imaged object as well as for registering the response of the nuclei or electrons to said signal. A control unit is used to control the above coils and to receive the information therefrom for producing an image or some other representation thereof.

Dependencies are inferred from the claim text.