Why can’t I adjust the concatenation mode?

The concatenation mode can only be adjusted when it is set to Manual.

To change it:

1. Open the sequence and go to the Sequence tab.
2. Set Concatenations Mode to Manual.
3. The Number of Concatenations field will then become editable.

When Concatenations Mode is set to Automatic, the number of concatenations is calculated automatically based on the repetition time (TR) and the number of slices, and cannot be manually changed.