Hydrogen 1 MR Spectroscopic Findings of Extraaxial Brain Tumors: Comparison with Primary Intraaxial Tumors

초록

Purpose: To evaluate the spectral patterns of hydrogen 1 MR spectroscopy of primary extraaxial brain tumors and to compare them with those of primary intraaxial brain tumors. Materials and Methods: Image guided hydrogen 1 MR spectroscopy was performed in 34 tumors of 33 patients with primary extraaxial brain tumors including meningiomas (n=27), schwannoma (n=4), and pituitary adenoma(n=3). Forty five intraaxial tumors ( 14 bengin and 32 malignant tumors) were also evaluated for comparison. Spectra were acquired using both STEAM pulse sequence with a 30-msec echo time and PRESS pulse sequence with a 135-msec echo time in all patients. Results: The spectral patterns of extraaxial tumors on hydrogen 1 MR spectroscopy were small sized lipid and/or lactate (lipid or lactate/choline <1), large choline compounds (Cho), and small or no creatine compounds (Cr) and N-acetyl aspartate (NAA) peaks. In contrast with these spectral patterns, those of primary benign brain tumors were small lipid and/or lactate, large Cho peak, and small or large Cr and NAA signals. On the other hand, the spectra of the primary malignant tumors were large lipid and/or lactate signals, large Cho, and small or noCr and NAA peaks. Conclusions: The spectral patterns of extraaxial tumors that could be differentiated from intraaxial tumors were small or no Cr and NAA peaks for benign tumors and small size of the lipid and/or lactate signals for malignant tumors.