Neuroimaging

AFNI know-how

Preprocessing

• Data import
  • use to3d or dimon to convert raw images into AFNI BRIK format

Region-of-Interest (ROI)

• Creating a half hemisphere mask

#left hemisphere selected
3dcalc -a mask_group+tlrc. -expr 'step(x-0)' -prefix test

#intersection with brain mask, and save in rh_mask+tlrc
3dcalc -a mask_group+tlrc. -b test+tlrc -expr 'step(a*b)' \
       -prefix rh_mask

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BrainVoyager QX know-how

Group analysis

• Created individual vmps[1]
• Paired t-test on vmps[2]

Multiple comparison

• Cluster threshold estimation (CTE)
  • Forming valid mask[3]
  • Masking and cluster thresholding[4]
  • CTE in BVQX vs. other softwares (AFNI, SPM)[5]
  • Solution to "Mask Not Valid!!" problem in CTE