ANALYSIS OF BRAIN-TUMORS USING H-1 MAGNETIC-RESONANCE SPECTROSCOPY

BACKGROUND Magnetic resonance imaging (MRI) is superior in delineating anatomic and pathologic information and has subsequently been married to the ability of magnetic resonance spectroscopy (MRS) to provide in sight into the biochemical changes underlying pathology. Proton magnet ic resonance spectroscopy (H-1 MRS) allows the noninvasive in vivo col lection and measurement of chemical information from a selected volume of tissue (voxel). METHODS We conducted a prospective trial in 23 pat ients with brain mass lesions and 16 normal subjects using proton magn etic resonance spectroscopy (H-1 MRS). The spectra were analyzed for N -acetyl-aspartate (NAA), choline compounds (Cho), creatine (Cr), and l actate (Lac). The ratios of the compounds in tumors were compared to n ormals. RESULTS The tumors showed significant decreases in the mean pe ak height ratios of NAA/Cho, NAA/Cr, and significant increases in Cho/ Cr when compared to tissue from normal subjects. Cho was elevated in a ll of the meningiomas and gliomas. In benign tumors, Cho was usually e levated while in metastases Cho was often normal or decreased. The fou r metastatic tumors showed NAA/Cho, NAA/Cr, and Cho/Cr that were simil ar to controls. tac varied with tumor type and was elevated in many ma lignant primary brain tumors. CONCLUSIONS H-1 MRS is a powerful tool f or safe, noninvasive analysis of tissue chemistry in vivo. Analysis of intracranial tumors reveals significant trends that might eventually be used in the classification of tumor histology and evaluation of the efficacy of tumor treatment.