Phosphorus and proton NMR studies of in-situ sarcomas and brain tumors

Adult patients with brain tumors or soft- tissue sarcoma were studied with localized spectroscopy on an MR imager. Clinical examination procedures have been developed for obtaining localized P-31 spectra from these tumors by one-, two- and three-dimensional chemical shift imaging (CSI), and localized, water-suppressed H-1 spectra from brain tumors by the stimulated echo (STEAM) technique. Voxel sizes currently are 27 cm for H-1 and 27-48 cm3 for P-31 three-dimensional CSI exams. CSI yields spectra from multiple contiguous volumes across the VOI, which can be mapped on H-1 images and realigned retrospectively for optimal sampling of the tumor region. Analysis programs incorporating the piqable algorithm provide spectral parameters (peak amplitudes, area, pH) displayed as metabolic maps or as overlays on the H-1 images. Metabolic information obtained from localized spectra provides new insight into correlations with tumor type and response to treatment