The role of MR diffusion tenser imaging in evaluating the relationship between the grade of gliomas and the state of adjacent fiber tract / 中华放射学杂志

Objective To investigate the relationship between the grade of gliomas and the status of adjacent fiber tract with DTL Methods MRI and DTI were performed in 24 patients with histologically confirmed brain gliomas.Regions of interest were placed in the white matter adjacent to the tumor with the lowest FA(Faa) and in the white matter of the contralateral hemisphere(Fac).The values of Faa and Fac were measured.In the regions of the same slice, the values of ADCa and ADCc were measured. Relative fractional anisotropy ratios (rFA) and relative apparent diffusion coefficient ratios (rADC) were also calculated.The status of fiber tracts adjacent to the gliomas were characterized as displacement, infiltration or disruption.Fiber tracking using the Fiber Assignment by Continuous Tracking (FACT) method was performed to investigate the integrity of white matter tracts in the surrounding border zone of the gliomas.The correlation of rFA, rADC, the state of adjacent fiber tracts, and the grade of gliomas were analyzed statistically by using independent sample t test and tendency X2 test.Results Eleven of the 24 tumors were demonstrated as low grade gliomas (WHO grade Ⅰ-Ⅱ) and 13 were high grade giiomas (WHO grade Ⅲ-Ⅳ).The average rFA and rADC of the low grade gliomas were 0.65±0.19 and 1.43 ± 0.50 respectively.Most of fiber tracts in the periphery of the low grade gliomas were displaced or infiltrated.The average rFA and rADC of the high grade gliomas were 1.51 ± 0.39 and 1.70 ±0.27 respectively.Most of fiber tracts in the periphery of the high grade gliomas were infiltrated or disrupted.Significant difference was found for rFA (t =8.504,P =0.000) and but not for rADC(t = - 1.435 ,P =0.165) between low grade and high grade gliomas.Significant difference existed between the state of fiber tracts adjacent to ghomas and low and high-grade(X2 =5.882 ,P =0.015).Conclusions The malignancy of gliomas influences the state of fiber tracts in the vicinity of tumors, rFA can serve as a reference for distinguishment of high-grade and low-grade gliomas.DTI can depict the localization of gliomas and the adjacent fiber tracts.The state of fiber tracts can also be identified by DTI.It is helpful for the therapeutic plan of the tumors.

The Role of Relative Fractional Anisotropy (rFA) and Relative Apparent Diffusion Coefficient (rADC) in Evaluating Tumor Grade in Gliomas / 实用放射学杂志

0.05). The rFA2 values were higher and rFA3 were lower in high grade gliomas than that in low grade and had significant difference (respectively t=2.453, P