Mapping sodium relaxation parameters in brain using magnetic resonance fingerprinting at 7T

We present a new MRF technique for simultaneous mapping of sodium T1, biexponential T2*, ion density, B+1 shift and B0 in the brain at 7T. This is accomplished using a 23 pulse MRF train combined with a UTE FLORET trajectory readout. Our technique is demonstrated in a 3 compartment phantom and in vivo across four healthy volunteers. Matching to a dictionary with over 800,000 signals produced parameter maps with good agreement to literature values. Flow and partial volume effects may interfere with matching T*2,short in CSF.