SVT_MNI9_5_2_SS_flt

purpose
usage
examples

Purpose:

This SVT command is used to statistically analyze the variations between two human brain functional volumes obtained under different stumulation paradigms.

You need to have the two stereotactic data sets pre-processed according to the SVT manual. The output SVT volumes are 4 bytes per pixel (floating point) stereotactic images of size 181x217y181z. Intensities are positive and represent the Z-scores of statistical significance of the difference image.

Usage:

SVT_MNI9_5_2_SS_flt A_postprocessed.img R_postprocessed.img Prob_Atlas.img SVT_SS_Pos.img SVT_SS_Neg.img

Usually we refer to the first paradigm as A(ctivation) and the second one as R(est). Let A.img and R.img be the two volumes we are analyzing and let T.img be our anatomical reference (template, "avgedit.img"). We denote by A_2_R.img the warped-and-resliced (using any algorithm) A.img in R.img space. There are at least 3 different ways one can transform A.img and R.img in T.img space, see SVT manual.

In the above the following definitions are used:
A_postprocessed.img The A(ctivation) state is warped in T.img space (A_2_T.img) R_postprocessed.img The R(est) state is warped in T.img space (R_2_T.img) Prob_Atlas.img The name of the file containing the probabilistic Atlas (lobes5_diff_intensLikeAve1.img) SVT_SS_Pos.img and SVT_SS_Neg.img The positive and negative statistically significant images, as output of the SVT analysis.

Examples:

./SVT_MNI9_5_2_SS_flt ./Act_After_Warp_2_avgedit_linWp12p.img ./Rest_After_Warp_avgedit_linWp12p.img ./lobes5_diff_intensLikeAve1.img ./Act_Rest_SVT_SS_Pos.img ./Act_Rest_SVT_SS_Neg.img

This command will use the post-processed data (A and B are warped directly to the template using a 12-parameter affine alignment) and the probabilistic partitioning information contained in "lobes9_diff_intens.img" to generate SVT output volumes (Act_Rest_SVT_SS_Pos.img & Act_Rest_SVT_SS_Neg.img) of the statistically significant differences between the data sets. Also look at the batch file "batch_SVT_SS". Note that the above example represents a single UNIX command-line.

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