HOPE, a New Lactate Editing Method

A new method is presented for localized editing of weakly homonuclear coupled AX3systems as, for example, lactate. It is based on the volume-selective PRESS sequence, using the properties of homonuclear polarization transfer. The efficiency of the method is demonstrated by measurements on different phantoms containing lactate and acetic acid or fat. Lactate and lipid proton signals can be well discriminated by this technique which additionally provides high signal-to-noise ratio within relatively short measuring times. The suppression factors achievable for uncoupled resonances are greater than 500, depending on their transverse-relaxation time. Signals with aT2of 80 ms, as from lipid methylene protons, can be suppressed by a factor greater than 1500. Compared to regular PRESS, the signal loss of the lactate doublet is less than 30% in the spectra presented.