The Application Of DTI In The Diagnosis Of Different Types And Grades Of Brain Tumors

Objective:To explore the application of DTI in the classification and grading of brain tumors.Materials and Methods:A total of 48 patients with pathologically and clinically diagnosed brain tumors after diffusion-weighted imaging.(Including 23 males and 25 females;Age range is 16-71 years old,and the average age is 49.4±13.6 years old).There were 24 high-grade gliomas,9 low-grade gliomas,7 metastases,and 8 meningiomas.Performed routine MRI plain scan,MRI enhanced scan,DTI check before surgery,then generated the apparent diffusion coefficient diagram and the fractional anisotropy diagram at the workstation automatically.Measured the ADC values and FA values of the tumor parenchyma and contralateral mirror area;the ADC values and FA values of the edema area and contralateral mirror area around the tumor respectively.Analyzed and compared the ADC values and FA values between different tumors and between high-grade glioma and low-grade glioma.Through the post-processing software,the white matter fiber tracts map was drawn on the basis of the original DTI data.The white matter fiber tracts was reconstructed in the tumor area and the corresponding areas of the healthy side,then merged it with the tumor to observe the morphological changes of the peritumoral fiber tracts.All of these were to observe the changes in white matter fiber tracts which caused by different tumors,high-grade glioma and low-grade glioma.Results:1.The average ADC values of the parenchymal area of glioma,metastases,and meningioma: ADC1:1.076±0.215,ADC2:1.375±0.181,ADC3: 0.991±0.291.The average FA values: FA1: 0.134±0.041,FA2: 0.203±0.066,FA3: 0.221±0.057.Among them,the highest ADC value was in the parenchymal area of metastases and the lowest was in the parenchymal area of glioma;the highest FA value was in the parenchymal area of meningioma and the lowest was in the parenchymal area of glioma.Compared the ADC values and FA values between the parenchymal areas in each group and the mirrored area of the healthy side,the tumor values were statistically significant(P<0.001),expect meningioma(t=1.886,p=0.080).2.The average ADC values of the peritumoral area of glioma,metastases,and meningioma: ADC1:1.635±0.380,ADC2:1.574±0.275,ADC3: 1.382±0.474.The average FA values: FA1: 0.159±0.101,FA2: 0.153±0.064,FA3: 0.228±0.104.Among them,the highest ADC value was in the peritumoral area of glioma and the lowest was in the area of meningioma;the highest FA value was in the peritumoral are of meningioma and the lowest was in the area of metastases.Compared the ADC values and FA values between the peritumoral areas in each group and the mirrored area of the healthy side,the tumor values were statistically significant(P<0.001).3.Compared the ADC values and FA values of the parenchymal areas of glioma,metastasis and meningioma respectively,the result is that the highest ADC value was in the parenchymal area of metastases and the lowest FA value was in the area of glioma.Through the comparison between groups,there was no statistically significant difference in ADC values between glioma and meningiomas(t=0.769,p=0.462);and was no statistically significant difference in FA values between metastasis and meningioma(t=-0.565,p=0.583).4.Compared the ADC values and FA values of the peritumoral areas of glioma,metastasis and meningioma respectively,the result is that the highest ADC value was in the peritumoral area of glioma and the lowest FA value was in the area of high-grade glioma.Through the comparison between groups,there was no statistically significant difference in all date(p>0.05).5.Compared the ADC values and FA values in parenchymal and peritumoral areas between high-grade glioma and low-grade glioma.In the parenchymal area,the FA value was not statistically significant(t=-0.103,p=0.918);And in the peritumoral areas,the ADC value was not statistically significant,neither(t=1.599,p=0.136).As for FA value,there was statistically significant when taking the equivalent variable and was not statistically significant when it not.6.Image analysis of DTI reconstruction of high-grade glioma,low-grade glioma,metastases and meningiomas: low-grade gliomas and meningioma mainly compress and push peripheral white matter fiber tracts and make them transmutative and biased;High-grade gliomas and metastases mainly infiltrate and destroy them,in addition to transmutative and biased,they also discontinuous and missing at same time.Conclusions:1.Compared the ADC values and FA values between different tumors: there was no significant difference in ADC values between glioma and meningioma;and had difference in other groups.There was no significant difference in FA values between metastasis and meningioma;and had difference in other groups.2.The ADC values had difference between high-grade glioma and low-grade glioma;The FA values had not.3.Compared the ADC values and FA values in peritumoral area: There had no difference between different tumors and different grades of tumor peritumoral area.4.Compared with conventional MRI,DTI can observe the relationship between tumor and peripheral white matter fiber tracts more intuitively.So,it can provide more information for the diagnosis and differential diagnosis.And provide important date for developing surgical plan,determining the extent of resection and taking postoperative follow-up.