MULTIVOXEL PROTON MR SPECTROSCOPY AND HEMODYNAMIC MR-IMAGING OF CHILDHOOD BRAIN-TUMORS - PRELIMINARY-OBSERVATIONS

PURPOSE: To assess multivoxel proton MR spectroscopy combined with MR imaging and hemodynamic MR imaging in the evaluation of brain tumors i n children and young adults. METHODS: Fifteen patients with brain tumo rs and 10 healthy children underwent MR imaging and MR spectroscopy on a 1.5-7 system. Ten patients with tumors had both MR spectroscopy and hemodynamic MR imaging. MR spectroscopy data sets with 1 cm(3) to 3.4 cm(3) resolution were acquired within 8.5 minutes by using a point-re solved spectroscopic, chemical-shift imaging technique in two dimensio ns with volume preselection. MR imaging was performed using fast spin- echo techniques. Hemodynamic MR imaging data were acquired every 2.5 s econds at one anatomic level using a spoiled gradient-echo sequence du ring intravenous bolus administration of contrast material, RESULTS: A ssessment with multivoxel MR spectroscopy and hemodynamic MR imaging a dded about 30 minutes to the total MR examination time. Normal tissue exhibited spectral peaks from biologically significant compounds such as N-acetylaspartate (NAA), choline-containing compounds (Cho), and to tal creatine (tCr), Twelve biopsy-proved tumors exhibited prominent Ch o, reduced NAA, variable tCr, and/or lactate or lipids, and two showed increased hemodynamic parameters. Three of the tumors treated with ra diation did not reveal prominent levels of Cho. Tissue necrosis had no Cho, NAA, or tCr, and reduced hemodynamics. CONCLUSIONS: Preliminary findings by MR spectroscopy combined with MR imaging and hemodynamic M R imaging suggest that regions of active tumor may be differentiated f rom areas of normal tissue and areas of necrosis. These findings may e nable metabolic and hemodynamic characterization of childhood brain tu mors as well as suggest their response to therapy.