Optimisation of Simultaneously Acquired Single and Triple Quantum Filtered Sodium MRI for Relaxometry at 7T

Sodium relaxometry has great potential value for research and clinical practice. Enhanced Simultaneously Acquired Single and Triple Quantum Filtered Imaging of Sodium (eSISTINA) can yield information on both fast and slow transversal relaxation times. The eSISTINA sequence is optimised by adding an early echo in the multiple-quantum-filtered readout train using FLORET k-space trajectories. The optimised sequence is compared and verified against a conventional, Cartesian multi-echo gradient echo based enhanced eSISTINA sequence on a group of four healthy volunteers. The experimental results show that the optimised sequence has better in vivo relaxometry performance than the conventional sequence.