Detection of susceptibility effects using simultaneous T2∗ and magnetic field mapping

Tracking susceptibility effects is a convenient way to detect small inclusions in a bulk tissue matrix by MRI. We propose a quantitative assessment of these susceptibility effects by simultaneously mapping T2∗ and magnetic field from the time course of magnitude and phase using a multiple GE sequence at 4.7 T. A high-pass scheme is also introduced to highlight the mesoscopic magnetic field variations due to local susceptibility differences specifically in the magnetic field map. Applying this method to muscle tissue, we demonstrate that connective tissue generates detectable susceptibility effects through concomitant local magnetic field variation and T2∗ shortening.