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DIFF_CALC Fit

After registration, you will have some new files in your proc directory. The final results is contained in the _DMC.list file. Load the _DMC.list file into DIFF_CALC, and follow the same directions as for the quick linear fit, but change the settings to use nonlinear tensor fitting.

  • To do a nonlinear tensor fit:
    • First load your list file (after standard registration with DIFF_PREP, this will be called _DMC.list), and inspect the registered images.
    • Then click on estimate signal SD to estimate the image noise
    • Then click on mask raw images to calculate a brain mask
    • (Optional) Click on display mask to inspect the mask. If necessary, use the "opt" button beside the mask raw images button to adjust the masking parameters to create a better mask.
    • Then select the "opt" button to the right of the process tensor button and select the nonlinear fitting option
  • When the fit is complete, click on roi utilities to view the tensor derived metric maps. The tensor fitting can be checked for QC again by looking at the DEC no symmetry map and the linefield. However, if this was performed on the raw data, then it is unecessary at this time.