NAVIGATED SINGLE-VOXEL PROTON SPECTROSCOPY OF THE HUMAN LIVER

The addition of a navigator echo acquisition to a H-1 spectroscopy seq uence allows retrospective motion correction using acceptance criteria based on measured displacement of the diaphragm. This technique has b een applied to the acquisition of short echo-time H-1 spectroscopy of the liver in seven normal subjects. Navigation correction significantl y improved overall spectral quality as measured by the phase variance, linewidth and suppression ratio of the water resonance. The hepatic c holine resonance was consistently observed in all navigated spectra, R etrospective navigation makes close to optimal use of data acquisition time and, unlike external respiratory transducers, allows direct meas urement of diaphragm displacement. The reconstruction of multiple voxe l spectra from a single data set was also demonstrated.