[Freesurfer] Little cluster after FDR correction

Hi list, I have performed a seed-based fcMRI analysis by FAST.After mri_glmfit, I have obtained a sig.nii.gz which contains uncorrected results.I have corrected by FDR using the graphical interface provided in tksurfur. The FDR corrected contains some very small areas (<5-10 voxels) which I would like to hide in order to present a more clear map. How is possible to do it?I have tried with mri_surfcluster. To have vwsig.nii.gz I should have a CSD file. But this file could be also produced when FDR correction is applied? I'm very confused.Please, could you help me because from several days I'm trying to have a solution.Thank you very much for your work.Kind regards. Stefano