Fast and tissue-optimized mapping of magnetic susceptibility and T2* with multi-echo and multi-shot spirals.

Gradient-echo MRI of resonance-frequency shift and T2* values exhibit unique tissue contrast and offer relevant physiological information. However, acquiring 3D-phase images and T2* maps with the standard spoiled gradient echo (SPGR) sequence is lengthy for routine imaging at high-spatial resolution and whole-brain coverage. In addition, with the standard SPGR sequence, optimal signal-to-noise ratio (SNR) cannot be achieved for every tissue type given their distributed resonance frequency and T2* value.