Relationship between annotation volume and structure tree

Hi there,

Each element of the 3d annotation volume contains a single number representing the brain area that that element occupies. I was wanting to confirm which value in the structure tree this single number refers to.

The structure tree is a table with columns including ‘index’, ‘id’, and ‘atlas id’. Moreover, the row numbers in the structure tree table are different from any of these 3 columns (e.g. row 1 has an ‘index’ of 0).

Which number do the values in av refer to in the structure tree table? ‘index’, ‘id’, ‘atlas id’, or row number?