Investigation of creatin levels between low and high grade glial tumors using MR spectroscopy

Objective: To discriminate the creatine changes in single and multivoxel MR-Spectroscopy (MRS) in patients with glial tumor, and investigate the creatine level differences between high and low grade glial tumors. Materials and methods: The patiens with a glial tumor diagnosed between 07-2010 and 12-2015 were retrospectively evaluated in our study. Among 32 patients, 20 patiens had single voxel MRS measurement from tumoral and contralateral sites, 20 patients had multivoxel measurements. In single voxel study, Cr(area) and Cr(height), (Cho+Cr)/NAA and Cho/NAA measurements from tumoral site were compared to contralateral normal site. In multivoxel study, the highest and lowest Cr(height) containing voxels in tumoral area were noted, Cr(h) and Cho/NAA values were noted and compared with symetric contralateral healty voxels. The distibution in dataset were evaluated using Kolmogorov-Smirnov test and compared using paired-samples t-test. Pearson correlation test were used to asses the correlation between values. Results: When all the patients were included in study, no correlation between Cr(a) and Cr(h) measurements between tumoral and healty sites were detected in single voxel measurements (p:0,104 and 0,553 respectively). The (Cho+Cr)/NAA and Cho/NAA measurements between tumoral and healty sites using SV study showed statistically significant difference (p:0 and 0 respectively) In multivoxel study the comparison of lowest Cr(h) values from tumoral and contralateral site showed no significant difference (P=0,131). But significant difference was noted when the highest Cr(h) values inside tumoral voxels were compared with the contralateral healty values (P=0,003). Cho/NAA ratios were significantly different between healty paranchyme, low Cr(h) containing and high Cr(h) containing groups (p=0). Among high Cr(h) and low Cr(h) containing voxels, the Cho/NAA ratios were significantly higher in low Cr(h) areas (p=0). Conclusion: We observed the the creatin levels varied inside tumor tissue. In multivoxel study the areas with respectively low Cr(h) values, the Cho/NAA ratios were significanly higher, indicating a higher tumoral grade area.