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Dear all VBM experts Currently, i follow the longitudinal DARTEL VBM pipeline of the following paper "Longitudinal loss of gray matter volume in patients with first-episode schizophrenia: DARTEL automated analysis and ROI validation" [http://www.ncbi.nlm.nih.gov/pubmed/21924364] to process the longitudinal T1 dataset. After reading this article, i have some analyses related questions and hope some of you could help me to overcome it. The questions were listed as follows: 1. After completing the whole preprocessing procedure, i will get three deformation files to map the individual tissue segments of each time points from rigid-align space to MNI space (with-in subject DARTEL, between subject DARTEL and DARTEL to MNI space). Could someone help me how to composite these three transformation information into one deformation file using SPM to avoid interpolation artifact ? 2. In cross-sectional DARTEL VBM, we can use the "Normalize to MNI space" function in DARTEL toolbox to normalize the rigid_align_space_tissue_segments to MNI space and perform tissue modulation simultaneously. In the current longitudinal pipeline, how could i normalize the individual rigid_align_tissue_segments of each time points to the MNI space and also perform tissue modulation with the composite deformation file (which comes from Question 1) using SPM ? 3. About how to obtain the transformation matrix of "DARTEL average space to MNI space": After searching the SPM archives, some experts provide the approach for calculating the transformation matrix using "Normalize" function in SPM (with Nonlinear freq cutoff: Inf; nonlinear iterations: 0; and/or nonlinear regularization: Inf; 0 weighting; template smoothing 0 mm, source image smoothing 8 mm; Affine regularization ICBM template), however, it seems the "normalize to MNI space" function which used in SPM8 DARTEL toolbox using the different registration algorithm for registe the DARTEL_Template_6 to the MNI space GM templates. Which approach is the most appropriate method for current DARTEL to MNI space registration? Many thanks and hope to get some feedbacks from kindly experts Best Paul