bvals and becs

Page Contents

Note that the bvals file will often be identical for all subjects in a study, so you can just copy the same bvals4tracula.txt for all subejcts.

Find the bvals file (e.g., V:\LinuxShare\subjects4FSL\CON302\DTI_b0corr\bvals) and open it in Excel

• Open Excel
• File => Open (or Ctrl^O)
• Change type to "All Files"
• Select bvals, click Open

• In the Text Import Wizard
  • Step 1 choose "Delimited" (click Next)
  • Step 2 check "Space" (click Finish)

The values will appear as one row.

Get values in column format

• Select the row of values, and Copy.
• Go to an empty cell (next row down)
• Paste Special,* select Transpose option

* To get to Paste Special, from Home tab in ribbon, click small down-arrow below "Paste", or after pasting, click on Paste options ("Ctr" usually on right).

Create new text file with column-format bvals

• Open Notepad
• Copy the column of bvals (make sure you don't include cells on the top row)
• Paste into Notepad
• Save as bvals4tracula.txt in the same folder as the bvals file

Create bvecs file

Repeat these steps for the bvecs file; the difference is that there are three measure for each volume, so you will be starting with three rows in bvecs, and creating three columns in bvecs4tracula.txt.