[Freesurfer] creating a multi-scanner template?

Dear all,

I am planning to create a "local cortical thickness normal template" in order to test single patients against it.

For that purpose I was planning to use 50-100 MPRAGE scans of healthy subjects (balanced for age range and sex).

My question is, if I should worry about the scanner where the data comes form. We have three Siemens Trios, the MPRAGES are more or less the same protocols.

- when the created template with standart deviation map comes from all three scanners, can I test patients coming from all three scanners? Will it reduce sensitivity?

- when the created template comes from only one scanner, it is clear that I will not be able to compare patients coming from another scanner against it.

Thank you!

Markus