Talairach Transformation File

Module information
Modules	BESA Research Basic or higher
Version	5.2 or higher

The tal file contains the transformation parameters from AC-PC coordinate system to the Talairach coordinate system. The following seven points are listed:

1. Item 1 AP: Distance from x-z-plane at y==AC to anterior point (AP) along the y axis
2. Item 2 PC: Distance from x-z-plane at y==AC to posterior commissure (PC) along the y axis
3. Item 3 PP: Distance from x-z-plane at y==AC to posterior point (PP) along the y axis
4. Item 4 SP: Distance from x-y-plane at z==AC to superior point (SP) along the z axis
5. Item 5 IP: Distance from x-y-plane at z==AC to inferior point (IP) along the z axis
6. Item 6 RP: Distance from y-z-plane at x==AC to right point (RP) along the x axis
7. Item 7 LP: Distance from y-z-plane at x==AC to left point (LP) along the x axis

Example file content:

66.885850 26.500000 102.697017 68.035304 40.421205 65.232346 64.500000

Using these points, the transformation is then performed as shown in the figure and example below.

The default values are as such (all distances in mm):

Distance AC to AP		70
Distance AC to PC		23
Distance AC to PP		102
Distance AC to SP		74
Distance AC to IP		42
Distance AC to RP		68
Distance AC to LP		68