4816764 Method for the identification of nuclear magnetic spectra from spatially selectable regions of an examination subject

Abstract

An apparatus for identifying nuclear magnetic spectra from spatially selectable regions of an examination subject supplies pulse signals to the examination subject in the following sequence. A first, non-selective 90° RF pulse is supplied to the patient so that the magnetization of the examination subject is oriented out of the z-direction into an x-y plane perpendicular thereto. A first, selective 180° RF pulse is then supplied simultaneously with a first magnetic gradient G z which effects a dephasing of the spins outside of a first, selected slice S 1 . A second, selective 180° RF pulse is then supplied simultaneously with a second magnetic gradient G x disposed perpendicularly to the first magnetic gradient. The second magnetic gradient effects a dephasing of the spins outside of a second selected slice S 2 . A second, selective 90° RF pulse is then supplied simultaneously with a third magnetic gradient G y , which is disposed perpendicularly relative to the first and second magnetic gradients. A third 90° RF pulse is then supplied, and the signal emitted by the examination subject in response thereto is evaluated.