Three-dimensional magnetic resonance spectroscopic imaging of histologically confirmed brain tumors

The goal of this study was to determine whether presurgical metabolite leve ls measured by 3D MR Spectroscopic Imaging (MRSI) can accurately detect via ble cancer within human brain tumor masses. A total of 31 patients (33 exam s, 39 pathology correlations) with brain tumors were studied prior to surgi cal biopsy and/or resection. The 3D MRSI was obtained with a spatial resolu tion of 0.2 to 1 cc throughout the majority of the mass and adjacent brain tissue using PRESS-CSI localization. Levels of choline, creatine and NAA we re estimated from the locations of the resected tissue and normalized to no rmal appearing brain tissue. The data were correlated with subsequent histo logic analysis of the biopsy tissue samples. Although there were large vari ations in the metabolite ratios, all regions of confirmed cancer demonstrat ed significant choline levels and a mean choline/NAA ratio of 5.84 + 2.58 w ith the lowest value being 1.3. This lowest value is greater than 4 standar d deviations above the mean (0.52 +/- 0.13) found in 8 normal volunteers. T he choline signal intensities in confirmed cancers were significantly eleva ted compared to normal appearing brain tissue with a mean ratio of 1.71 +/- 0.69. Spectra with no significant metabolite levels were observed in the n on-enhancing necrotic core of the tumor masses. The results of this study i ndicate that 3D MRSI of brain tumors can detect abnormal metabolite levels in regions of viable cancer and grades and can differentiate cancer from ne crosis and/or normal brain tissue. (C) 2001 Elsevier Science Inc. All right s reserved.