The Application Values Of 3.0T MR Perfusion Weighted Imaging And Diffusion Tensor Imaging In Grading Of Cerebral Gliomas

Objective: To study the application values of 3.0T MR PWI and DTI in grading of gliomas.Methods: 45 patients suffering from intracranial gliomas (22 case of low grade and 23 case of high grade gliomas, according to 2007 WHO criteria) were performed with MR examinal, including conventional MRI, diffusion tensor imaging (DTI) and perfusion weighted imaging (PWI). Quantitative parameters (ADC, FA, rCBF, rCBV) were measured on corresponding parameter maps generated from DTI or PWI raw data of solid regions of tumors, peritumoral regions and analogous locations in the contralateral WM corresponding to the tumor. Then these values were compared statistically between different groups. Receiver operating characteristic (ROC) analyses were performed to determine optimum thresholds for grading and also to calculate the sensitivity and specificity for tumor grading.Results:①There was a strong correlation between the rCBF and rCBV of the solid regions of tumors of 45 cases of cerebral gliomas(R2=0.9388,P﹤0.001).②To compare the values of ADC, FA, rCBF, rCBV of solid regions of tumor, peritumoral region and normal white matter respectively. There were significant differences between these values (P﹤0.05).③The difference of relative rCBV (rrCBF) and relative ADC (rADC) of solid region of tumor between high and low grade gliomas was statistical (P﹤0.01). So was that of the rrCBV of peritumoral regions (P﹤0.01).④The threshold of rrCBF, rrCBV, ADC of solid region of tumors were 2.749, 3.058 and 13.95×10-10m2/s respectively, and the diagnosis sensibility were 87%, 91.3% and 81.8% respectively, and the specificity were 100%, 95.5% and 91.3% respectively. All of rrCBF, rrCBV, ADC of solid region of tumors showed high diagnosis accuracy.Conclusion: The threshold of rrCBF, rrCBV, ADC of solid region of tumors were 2.749, 3.058 and 13.95×10-10m2/s respectively, are beneficial to differentiate high and low grade gliomas. Threshold values can be used in clinical setting to evaluate tumors for histological grade of cerebral glioma preoperatively.