| Objective:To investigate the diffusion characteristics of pyramidal tract of normal adult, describe the fractional anisotropy (FA) and mean diffusibility (MD), and its relationship with age.Materials and Methods:1. Investigate objects:50normal people (27men,23women; age range6-58years, mean age31.7years) were included in this study. All subjects have no neurological diseases or disorders affect the central nervous system.2. MR equipment and sequence:The examination all with GE Signa Excite3.0T using8channels head coil. The conventional MR imaging brain protocol include axial and sagittal T1-weight, axial T2-weighted imaging, T2-weighted fluid attenuated inversion recovery and diffusion weight imaging,5-mm slice thickness, with1-mm gap, FOV240×240mm2. DTI scan:Use of EPI sequence with diffusion sensitive gradients in25directions, b value is equal to1000s/mm2.3. Post-processing:With the help of AW4.3workstation, using Functool software to obtain fractional anisotropy (FA) maps and color coded the direction (DEC) maps. Placed regions of interest in midbrain, pons and medulla of bilateral brainstem, respectively, using the software at different levels of color-coded map to delineate motor and sensory tract. FA, MD, λ1,λ2and λ3for each ROI were calculated. MD were derived according to the following equations:MD=λ1+λ2+λ3/3.4. Statistical analysis:Data were analyed using the Statistical Package for Social Sciences(SPSS13.0), A P-value of0.05was considered statistically significant. The data of FA, and MD of the bilateral brainstem using Paired-Sample T Test. The data of FA, and MD of different gender using Independent-Sample T Test. The data of different age-group and different positon using analysis of variance of factorial design. The multiple comparison using LSD-t test when homogeneity of variance, and using Dunnett’s T3test when heterogeneity of variance.The FA, MD values were correlated with age using pearson correlation.Results:1.The diffusion and anisotropic characteristics of normal CST and ML(1) The FA and MD values of bilateral brainstm symmetrical parts were not statistically significant difference (P>0.05). The FA/MD value was no significant difference between Men and women (P>0.05).(2) The FA/MD values of the difference planes of CST/ML were statistically significant difference (P<0.001)(3) The FA values of the different age-group of CST/ML were statistically significant difference (P<0.001). The MD values of the different age-group of ML were statistically significence (P<0.005). The MD values of the differentage-group of CST of the different age-group of ML were not significant difference(P>0.05).2. The correlation of FA/MD of CST/ML in different structures with age(1) CST:The FA value of midbrain, pons and medulla were negatively correlated with age (P<0.001). The MD values in different position have a incremental trend with age increase and have no statistical significance (P>0.05)(2) ML:The FA value of midbrain and pons were negatively correlated with age (P<0.001). The FA value of and medulla have a downward trend, and have no statistical significance (P=0.113). The MD values in different position have a incremental trend with age increase and have no statistical significance (P>0.05)Conclusions:1.3.0T magnetic resonance DTI technology can be a very good method to display the anatomy of the CST and ML on brainstem, which can precise location for the study and quantitative analysis of micro-structural changes of CST and ML in the brainstem.2. Anisotropy of CST and ML in normal is related with age, and there is a certain patterns.3.With the help of diffusion tensor tractography we can observe the CST/ML three dimensional, provide a visualized method for the study of disease correlated with CST and ML. Objective:Study of brainstem tumors and its surrounding tumors with3.0TMR for the use of DTI and DTT technology. To explore the change of CST and ML of this tumors, and its relationship with the clinical symptom. To explore clinical application of DTI and DTT technology in the brainstem tumors and its surrounding tumors.Materials and Methods:1. Investigate objects:20brainstms tumurs(12men,8women; age range4～55years, mean age25.3years) and15tumors surrounding brainstem(7men,8women; age range5-59years, mean age33.9years) were included in this study. The neurological examination of preoperative and postoperative were performed of all patients. The motor system disorders, sensory function obstacle and cranial never symptom were classified. The normal control group are same as first.2. MR equipment, sequence and Post-processing are same as first part.3. Statistical analysis:Data were analyed using the Statistical Package for Social Sciences(SPSS13.0), A P-value of0.05was considered statistically significant. The damage degree of tracts were correlated with clinical symptom using Spearman correlation. Results:1. The value of DTI/DTT technology in the evaluation of CST and ML of patients with brainstem tumors(1) Evaluation of neurologic deficits of motor and sensory:The results of neurologic deficits of motor:18patients were absent,12patients were mild,5patients were moderate, no patient was severe. The results of neurologic deficits of sensory:21patients were absent,6patients were mild,8patients were moderate, no patient was severe.(2) Evaluation of CST and ML of patients with DTI and DTT technologyThe results of CST:21were nomal,19were displaced,22were edematous orinfiltrated,8were destroyed. The results of ML:18were nomal,22weredisplaced,26were edematous or infiltrated,4were destroyed.(3) The clinical symptom of patients was positively correlated with thedamage degree of tracts (CST:r=0.786, P<0.01; ML:r=0.686, P<0.01).2. DTI and DTT in preoperative and postoperative study of brainstem tumors.The DTI and DTT technology can two-and three-dimensiomally shows the relationship of tumors and fiber tracts. It is very important to protect these fiber tracts in the perioperative, as well as monitoring prognosis.Conclusions:1. DTI and DTT technology can be used to evaluation of corticospinal tract and medial lemnicus.2. The DTI and DTT technology can shows the relationship of tumors and fiber tracts. It is very important to protect these fiber tracts in the perioperative, as well as monitoring prognosis.. |
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