HETERONUCLEAR MULTIVOXEL SPECTROSCOPY OF IN-VIVO HUMAN BRAIN - 2-DIMENSIONAL PROTON INTERLEAVED WITH 3-DIMENSIONAL H-1-DECOUPLED PHOSPHORUSCHEMICAL-SHIFT IMAGING

Multivoxel, heteronuclear interleaved two-dimensional proton and three -dimensional H-1-decoupled P-31 CSI Of human brain is demonstrated. Th is method offers efficient use of limited examination time as patient preparation, coil tuning, shimming and imaging are done only once and the CSI data sets from both nuclei are obtained concurrently, Effectiv e interleaving of P-31 and H-1 is possible due to the shorter T(1)s of proton brain metabolites, alllowing a H-1 acquisition cycle to be ins erted into each P-31 TR. This way, the entire MRS time is available to both nuclei, increasing their SNR per-unit-time by similar to 12% for P-31 and similar to 80% for H-1, compared with sequential detection o f equal (45-60 min) length. The spectral resolution and SNR of P-31 ar e further increased through bi-level H-1-decoupling and NOE.