Jullie W. Pan1,2, Nikolai Avdievich1, Jonathan Knisely3, Hoby P. Hetherington1
1Neurosurgery, Yale University School of Medicine, New Haven, CT, USA; 2BME, Yale University School of Medicine, New Haven, CT, USA; 3Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
Because of reduced spectral overlap and sensitivity to B0 inhomogeneity, 31P MRSI is advantageous for whole brain studies. 31P MRS is also sensitive to chemical exchange, this aspect not widely utilized for human brain studies. The SNR limitation of 31P MRSI can be offset by acquiring data at 7T. We measured the T1s of PCr, ATP and Pi at 7T using a multi-tip IR sequence and a 3site exchange model. In brain tumor patients, 31P SI show dramatic reductions in PCr with normal ATP levels, arguing that the reduced PCr signal results from lower concentrations, not only chemical exchange differences.