本教程详细介绍在TBSS框架下对扩散张量成像(DTI)数据进行预处理和分析的具体步骤,旨在帮助研究者掌握关键的操作流程和技术要点。
Detailed Steps for DTI Data Processing Using TBSS in FSL
1. **Data Preparation**: Begin by ensuring your diffusion tensor imaging (DTI) data is properly formatted and preprocessed according to the requirements of the Tract-Based Spatial Statistics (TBSS) method. This includes necessary steps such as eddy current correction, brain extraction, and tensor calculation.
2. **Normalization**: Use FSLs non-linear registration tool FNIRT for spatial normalization. Align all individual DTI datasets to a common space typically defined by the TBSS_FA template provided in FSL or an equivalent standard space relevant to your study population.
3. **Fiber-Oriented Tract Segmentation**: After normalization, perform fiber-orientation transformation (FLIRT) and create mean FA skeleton using tbss_2_preproc command. The skeleton represents the intersections of all subjects tracts and serves as a common reference for group comparison.
4. **Statistical Analysis**: Conduct voxel-wise statistical analysis comparing two or more groups by running TBSS statistics commands such as randomise in FSL, ensuring to correct for multiple comparisons using threshold-free cluster enhancement (TFCE).
5. **Visualization and Interpretation**: Visualize the results of your analyses on the mean FA skeleton. Use tools like fslview within FSL to overlay statistical maps onto individual or group-averaged images for better understanding.
6. **Reporting**: Document all steps taken in processing DTI data with TBSS, including any preprocessing adjustments made specific to your dataset and the rationale behind them. Ensure clarity on how each step contributes to the overall analysis of tract integrity across different populations or conditions being studied.
This workflow provides a structured approach for conducting robust TBSS analyses within FSL, aiming at reliable interpretation of white matter differences in DTI data.