High B-value Diffusion-weighted Imaging In The Evaluation Of Gliomas

Objective: The grade of glioma was analyzed by b value was1000s/mm~2、3000s/mm~2and5000s/mm~2respectively before operation, inorder to get the best b value to differentiate the tumor grade histopathology.Materials and Methods: ALL of the40patients undergo3.0T MRIstudy before operation (WHO grades I-II and III-IV were15and25patientsrespectively which confirmed by pathology). The signal intensity features andminimum ADC was retrospectively reviewed with b=1000s/mm~2、b=3000s/mm~2and b=5000s/mm~2.Result:1、Most high-grade tumor（92%）showed a hyper-intense, andmost low-grade tumor（80%）showed a hypo-intense when b=5000s/mm~2.The specificity and accuracy were high（92%and100%respectively）whenhyper-intense was taken as a diagnostic criteria of high-grade glioma.2、Theminimum ADC of high-grade glioma was significantly lower than low-gradeone with the same b value.3、The minimum ADC was inversely correlatedwith the histological grade of tumor and b=5000s/mm~2had the highestcorrelation.4、The operating characteristic (ROC) analysis suggested that theminimum ADC has a highest sitivity to differentiate high-grade and low-gradetumor when b=5000s/mm~2. The difference of sensitivity for three kinds of bvalue to high-grade and low-grade tumor had statistical significance.Conclusion: When b=5000s/mm~2on DWI, the minimum ADC washelpful to grading the glioma preoperatively. Objective: The glioma recurrence and Radiation-induced brain injurywas analyzed by b value was1000s/mm~2、3000s/mm~2and5000s/mm~2respectively before operation, to evaluate which one is better to distinguishthem.Materials and Methods:21patients who suffered glioma recurrenceand radiation-induced brain injury which were confirmed by surgery orfollow-up (16and5patients respectively) were retrospective analysis on3.0TMRI. The signal intensity features and minimum ADC of the solidenhancement part was retrospectively reviewed with b=1000s/mm~2、b=3000s/mm~2and b=5000s/mm~2.Result:1、All of the recurrent glioma (100%) showed a hyper-intense,and most radiation-induced brain injury patients (80%) showed a hypo-intense when b=5000s/mm~2.The specificity and accuracy were high (100%and80%respectively) when hyper-intense was taken as a diagnostic criteriaof glioma recurrence and radiation-induced brain injury.2、The minimumADC of glioma recurrence was significantly lower than radiation-inducedbrain injury with the same b value.3、The minimum ADC was inverselycorrelated with the glioma recurrence and radiation-induced brain injury andb=5000s/mm~2had the highest correlation.4、The operating characteristic(ROC) analysis suggested that the minimum ADC had a highest sitivity todifferentiate glioma recurrence and radiation-induced brain injury when b=5000s/mm~2. The difference of sensitivity and specificity for three kinds of b value to glioma relapse and radioactive brain damage had statisticalsignificance.Conclusion: High-b value was more accurately to reflect cell densityand the minimum ADC was better to grading the glioma recurrence andRadiation-induced brain injury when b=5000s/mm~2on DWI.