IMPROVED SENSITIVITY TO OVERLAPPING MULTIPLET SIGNALS IN IN-VIVO PROTON SPECTROSCOPY USING A MULTIECHO VOLUME SELECTIVE (CPRESS) EXPERIMENT

A method for volume selective proton spectroscopy is presented based o n a multiecho sequence with short refocusing interval top. It is demon strated, that by appropriate choice of top on the order of 4-6 ms, sig nals from overlapping multiplets like the glutamine and glutamate (Glu /Gln) resonances in spectra of the human brain are considerably increa sed compared with a conventional PRESS volume selection scheme. Thus p roton spectra from J-coupled multiplet signals can be acquired with TE on the order of 20-30 ms avoiding the baseline problems arising at sh orter echo times due to broad resonances. This allows to selectively a cquire spectra from substances with longer T-2 without the confounding effects from J-coupling occurring in conventional volume selection te chniques.