METABOLIC CHARACTERIZATION OF HUMAN NON-HODGKINS-LYMPHOMAS IN-VIVO WITH THE USE OF PROTON-DECOUPLED PHOSPHORUS MAGNETIC-RESONANCE SPECTROSCOPY

Development of biological and clinical uses of in vivo P-31 magnetic r esonance spectroscopy has been hampered by poor anatomic localization of spectra and poor resolution of overlapping signals within phosphomo noester and phosphodiester regions of the spectrum. We applied H-1-dec oupling and nuclear Overhauser enhancement to improve resolution of P- 31 magnetic resonance spectra accurately localized to 21 non-Hodgkin's lymphomas (NHL) by using three-dimensional chemical shift imaging. Al l 21 spectra had large phosphomonoester signals (26% of total phosphor us) that contained high amounts of phosphoethanolamine relative to pho sphocholine. There were no signals from glycerophosphoethanolamine or glycerophosphocholine but only a broad signal from membrane phospholip ids in the phosphodiester region (20% of phosphorus). Prominent nucleo side triphosphates (47% of phosphorus) and low inorganic phosphate (7% of phosphorus) indicate well-perfused tissue with viable cells. Mean intracellular pH was 7.23, These characteristics were similar in all g rades and stages of NHL. By analogy with recently reported studies in cell lines in vitro, we hypothesize that the pattern of phospholipid m etabolites observed in NHL in vivo is partly a manifestation of sustai ned activation of phospholipase C or D. The techniques we implemented permitted us to obtain more information about in vivo metabolism of NH L than has heretofore been available. This information is important fo r the establishment of appropriate experimental models and provides a basis from which to examine potential clinical uses of P-31 magnetic r esonance spectroscopy.