| Part I The role of diffusion tensor imaging in surgical planning of brain glioma involving insula and basal gangliaObjectTo investigate the value of diffusion tensor image (DTI) technique in surgical strategy making of insular and basal ganglia glioma.Material and methodsTwenty-one patients (12males and9females, age24to71years, mean age43.8±12.Oyears) were prospectively and consecutively studied. DTI was performed in all patients with radiologically indicated brain insular and basal ganglia glioma before operation. DTI data was processed by DTI studio software and bilateral pyramidal tract (PT) was constructed. According to the anatomical location revealed by preoperative regular MRI as well as the extent and the direction of PT displacement caused by tumor compression showed on three-dimension PT image, brain insular and basal ganglia glioma was classified as three subgroups:anterolateral type, posterolateral type and lateral type. DTI was useful in rational surgical strategy making. Follow-up DTI was performed to compare the change of PT placement pre and postoperatively within3to14days and/or3to25months respectively. Clinical presentation and prognosis of different subtype were analyzed. ResultsDTI data can be utilized to reconstruct bilateral PT and manifest the space relationship between tumor and peritumoral PT. The extent and the direction of PT displacement can be judged by three-dimension PT image. The improvement of surgical strategy, avoidance of PT injury and more rational surgical approach can be provided for neurosurgeons by DTI based three-dimension PT rebuilding. The preoperative deformed PT was recovered to the normal form after operation. The prognosis of patients in anterolateral subgroup was relative good, while the prognosis of patients in posterolateral subgroup was poor.ConclusionDTI fiber tracting has the potential to provide the anatomical information of the relationship between glioma in cerebral insular and basal ganglia region and adjacent PT, and provide the information of the states of peritumoral PT, which is valuable in preoperative surgical strategy making. Part II The role of DTI in evaluating the damage degree of pyramidal tract adjacent to glioma in insular and basal ganglial region of the brain and predicting the prognosis of the patientsObjectTo investigate the characteristic of water anisotropic diffusion along pyramidal tract adjacent to glioma in brain insula and basal ganglia, in combination with evaluating the correlations between the states of PT and motor function and life quality pre and post operation using diffusion tensor imaging (DTI) technique.Material and methodsFrom October2009to January2012,21patients (12males and9females, age24to71years, mean age43.8±12.Oyears) harboring tumors involving the insula and basal ganglia underwent surgical treatment. Seven patients were histopathologically confirmed as low-grade glioma, one of whom had astrocytoma WHO grade I, four of whom had astrocytoma WHO grade Ⅱ, two of whom had oligodendroglioma WHO grade Ⅱ. Fourteen patients had tumors found to be high-grade glioma, seven of whom were anaplastic astrocytoma WHO grade Ⅲ, two of whom had anaplastic oligodendroglioma WHO grade Ⅲ, four of whom had glioblastoma WHO grade IV and one of whom had glioma sarcomatosum WHO grade Ⅳ. Regular MRI and DTI were performed in all patients, to understand the relationship between tumor and PT, DTI studio software was employed to reconstruct the three-dimension image of PT. Follow-up DTI was performed within3to14days and/or3to25months respectively after surgery. Pre and post operative DTI data were analyzed by DTI studio software, the region of interest (ROI) was set in the posterior limb of internal capsule. FA and ADC values in the tumor side and the contralateral side were calculated, relative fractional anisotropy ratios (rFAt) and relative apparent diffusion coefficient ratios (rADCt) in tumor side were calculated. Extent of reconstructed PT injured by the tumor was classified as:intact, be compressed, be invaded and be destroyed. Calculating the absolute number of effective fibers of PT (EPT) in the tumor side and the opposite normal side, and then relative EPTt (rEPTt) can be calculated. Comparing the difference of FA and ADC value of posterior limb of internal capsule between the tumor side and the normal side using paired t-test method. Comparing the difference of rFAt and rADCt value in varied grades of glioma used ANOVA statistical method. Using Spearman rank correlation analysis to reveal the correlation between the value of rFAt, rADCt and rEPTt and postoperative muscle strength, KPS evaluation, pathological grade of glioma and the extent of PT injured by the tumor.Results1. The values of FA in the tumor side (FAt) were lower than the values of FA in the contralateral side (FAC), and the values of ADCt were higher than the values of ADCC. Paired t-test showed significant statistical difference between FAt value and FAC value in low-grade and high-grade gliomas (P<0.001and P<0.0001), and it also showed significant statistical difference of ADCt value and ADCC value in low-grade and high-grade gliomas (P<0.001and P<0.0001). The values of rFAt in low-grade glioma were statistically significant higher than that in high-grade glioma (p<0.05). The values of rADCt in high-grade glioma were higher than that in low-grade glioma but without statistical meaning (p>0.05). The values of rEPTt in low-grade glioma were statistically significant higher than that in high-grade glioma (p<0.05).2. Spearman rank correlation analysis revealed that there was a significant negative correlation between the values of rFAt and the pathological grade of glioma (p<0.01), whereas there were no significant correlations between the values of rADCt and rEPTt and the pathological grade of glioma (p>0.05).3. The values of rFAtand rEPTt had a significant positive correlation with the muscle strength in the opposite side of the tumor in combination with KPS evaluation, and had a significant negative correlation with the extent of injury of PT adjacent to the tumor. The values of rADCt had a significant negative correlation with the muscle strength in the opposite side of the tumor in combination with KPS evaluation, and had a significant positive correlation with the extent of injury of PT adjacent to the tumor. Patients had a poor prognosis when rEPTt values less than0.5.ConclusionThe relationship between glioma in brain insular and basal ganglia region can be explicitly manifested by DTI fiber tracting, which has the potential to provide accurate anatomical information for choosing an optimal surgical approach. The values of rFAt, rADCt and rEPTt can be used to differentiate malignant and benign tumor, and reflect the extent of PT injury and judge the muscle strength in the opposite side of the tumor in combination with patients’life quality after surgery. It’s noteworthy that there is a poor prognosis trend in patients with rEPTt less than0.5. |
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