Macromolecule resonances underlying metabolites in H-1 NMR spectra wer
e investigated in temporal lobe biopsy tissue from epilepsy patients a
nd from localized H-1 spectra of the brains of healthy volunteers. The
1(H) NMR spectrum of brain tissue was compared with that of cytosol a
nd dialyzed cytosol after removal of low molecular weight molecules (<
3500 daltons) at 8.4 and 2.1 Tesla. The assignment of specific resonan
ces to macromolecules in 2.1 Tesla, short-TE, localized human brain 1H
NMR spectra in vivo was made on the basis of a J-editing method using
the spectral parameters (delta J) and connectivities determined from
2D experiments in vitro. Two prominent connectivities associated with
macromolecules in vitro (0.93-2.05 delta and 1.6-3.00 delta) were also
detected in vivo by the J-editing method. Advantage was taken of the
large difference in measured T-1 relaxation times between macromolecul
e and metabolite resonances in the brain spectrum to acquire 'metaboli
te-nulled' macromolecule spectra. These spectra appear identical to th
e spectra of macromolecules isolated in vitro.