ABSTRACT
Objective To evaluate which b value is the best to distinguish the glioma recurrence and radiation-induced brain injury using DWI when b value were at 1 000 s/mm2、3 000 s/mm2 and 5 000 s/mm2 respectively.Methods Retrospective analysis the DWI of 21 patients who suffered from glioma recurrence and radiation-induced brain injury obtained on a 3T MRI scanner.Results (1)All recurrent glioma (100%)showed hyper-intense signal,while most radiation-induced brain injury patients (80%)showed hypo-in-tense signal when b=5 000 s/mm2 .The sensitivity and specificity were high (100% and 80% respectively)when hyper-intense sig-nal was taken as a diagnostic point of glioma recurrence and radiation-induced brain injury.(2)The receiver operating characteristic (ROC)curve analysis suggested that the minimum ADC resulted in a highest sensitivity to differentiate glioma recurrence from radi-ation-induced brain injury when b=5 000 s/mm.Conclusion High b-value is more accurate to reflect cell density,and the minimum ADC is better to differentiate the glioma recurrence and radiation-induced brain injury when b=5 000 s/mm2 on DWI.