NUCLEAR MAGNETIC RESONANCE IMAGING METHODS

摘要

To derive NMR imaging information an object is subjected to a static magnetic field on which is superimposed a sinusoidally time varying magnetic gradient field. A sequence of narrow 90 DEG rf pulses are applied around the instants when the gradient field has a zero value. The rf pulses have relative phase quadrature such that excited nuclei precess with accumulated phase in each sequence.