Patent ID: 6700372
Filing Date: 2004-03-02
Classification: G01N,G01R

Abstract:
A method for generating measurement signals in magnetic fields which are generated by an NMR MOUSE apparatus in a surrounding medium and whose changes are measured, said method comprising the steps of: generating a static magnetic polarization field B0, and, by means of a high frequency oscillation circuit, a pulsed magnetic measuring field B1 including high frequency impulses (T0, T1, T2 to Tn) occuring with a time spacing tEc, generating within a preparation period tEc/2 an additional pulsed magnetic field Bz whose polarity is changed within the preparation period after each high frequency pulse (T11, T12, T13, T14) and which is superimposed on said static magnetic measuring field thereby causing in the surrounding medium echo signals (S), measuring the echo signals (S) after an echo time tE, determining the orthogonal components of the echo signals magnetic polarization field B0 and of the pulsed magnetic measuring field B1 for determining the measurement signals, and repeatedly refocusing the echo signals S generated within the preparation period tEc/2 without pulsed additional magnetic fields by a gradient having twice the value and the opposite direction of the previous half wave gradient for providing contrast.