Patent ID: 6856133
Filing Date: 2005-02-15
Classification: G01N,G01R

Abstract:
1. A method for detecting a prescribed substance in a specimen, comprising: irradiating the nuclei of a specimen in which a prescribed substance is sought to be detected, with a pulse sequence comprising a plurality of pulses, wherein the pulse sequence includes pairs of pulses offset from each other by a prescribed phase shift to produce a plurality of nuclear resonance echo signals from the prescribed substance, if present; and analysing the echo signals to detect the presence of the prescribed substance, wherein the pulse sequence is a modified steady state free precession pulse sequence comprising paired pulses, each paired pulse of said pulse sequence being of the same duration, paired pulse separation and predetermined frequency, and the phase of each even paired pulse of said pulse sequence being shifted 90° with respect to each odd paired pulse of said pulse sequence, and wherein each pulse of said paired pulse is of the same phase, duration and pulse separation inside said paired pulse.