Applying The Combination Of 1H-MRS And DTI In Glioma Grading

Objective:To observe the value of applying 1H-MRS, DTI and their combination in brain glioma grading.Methods:31 subjects pathologically proved brain glioma were divided into 2 groups according to WHO grading method: low grade gliomas and high grade gliomas.Preoperative routine examination including MRI plain and enhancement scan, DTI and multi-single voxel 1H-MRS were all performed as the following steps:1.After multi voxel MRS examination, Tecplor Functool spectroscopy-2D Brain were used to obtain the pseudo-color map overlaying Cho/NAA value distribution upon the anatomical diagram, regions containing the most Cho/NAA value were selected to be ROI(region of interest).2.Single-voxel MRS examination were performed to ROI by the parameters of the value of NAA/Cr,Cho/Cr and Cho/NAA.3.DTI scanning was performed in three-dimensional lacating map, FA and ADC value of ROI were selected as parameters.Statistical methods based on quantitative parameters of single voxel MRI and DTI scan obtained analysis, analysis of these parameters on the high and low-grade gliomas grading capabilities.Results:1.Main manifestations of glioma in 1H-MRS are include: significantly icrease of Cho value, lower NAA value, inapparent change of Cr value. As a result, the rate of Cho/Cr and Cho/NAA rise, while the NAA/Cr falls down. Statistical analysis has come to the conclusion: in the low-grade group, Cho/Cr was 1.92±0.66, and NAA/Cr was 0.61±0.17, Cho/NAA was 3.51±1.78;as for high-grade group: Cho/Cr was2.48±0.68,NAA/Cr was 0.31±0.11,Cho/NAA was 8.58±2.59. There is a statistically significant difference between high-grade group and low-grade group in terms of their metabolites(P<0.05).2.Significance between high-graded and low-grade group are noticed judging by their FA and ADC value. Low-grade group: FA value was 0.093±0.02,ADC value was1.72±0.14;high value group:FA value was 0.136+0.03,ADC value was 1.56±0.12(unit:×10-3mm2/s),the difference is significant(P<0.5).3.Five groups of parameters were to be obtained by MRS and DTI examination:Cho/Cr,Cho/NAA,NAA/Cr,FA,ADC value. J value were determined by their classifiability, single parameter has a relatively low influence on grading glioma,among which Cho/NAA is the most influential, better than any parameters of DTI.4.The application of the combination of data obtained by MRS and DTI significantly improved the classifiability of glioma. Determining J value by the classifiability, the most optimal grading parameter combination was the one containing Cho/NAA and FA.Conclusion:1.There is an significant difference between high-grade and low-grade glioma in1H-MRS and DTI.2.Combined application of MRS and DTI examination facilitates the distinguishing of different grade of glioma, superior to any other examinations, and the most optimal parameter of which is the combination of Cho/NAA and FA in terms of classifiability.3.Supposing single examination were to be applied to grade the glioma, MRS relatively surpasses the DTI, whose most optimal parameter of classifiability is Cho/NAA.