The High B-values Of DWI In The Differential Diagnosis Between High-grade Gliomas And Solitary Metastases

Objective Purpose To optimize b values in diffusion weighted imaging(DWI) for diagnosing malignant glioma and solitary brain metastasis.Methods To collect the complete MRI data of 25 cases high-grade gliomas and 15 cases solitary metastases pathologically confirmed after surgery in our hospital,including conventional MRI scan、enhanced scan、DWI.Retrospectively analyzed the imaging features of all lesions and then send the original images of DWI to post-processing workstation ADW4.4, using Functoo to draw ADC map, then measuring the ADC values in each region of interest such as tumor parenchyma、peritumoral edema and contralateral normal white matter. Evaluating the significance of each parameter value in differential diagnosis of the two tumors.Results(1)Both of the average ADC values of high-grade glioma in tumor parenchyma and peritumoral area were higher than the relatively normal area, and pairwise comparisons were significantly different; Both of the average ADC values of solitary metastases in tumor parenchyma and peritumoral area were higher than the relatively normal area, there was a significant difference between the two by two.(2)The ADC values in parenchyma areas of high-grade gliomas and metastases had no significant difference,but the ADC values in peritumoral areas had a significant difference.(3)When b-value was 3000 s/mm2 and the area under the ROC curve of the peritumoral region was 0.98, the sensitivity, specificity, positive predictive value and negative predictive value were 100.0%, 89.0%,80.0% and 100.0% respectively.Conclusion The b-value of 3000 s/mm2 is optimal to diagnose high-grade gliomas and solitary metastases using peritumoral ADC.