Hello,

I am new in the field of rs-fMRI analyses and need your advice. My problem is about whether my patients are comparable in terms of connectivity due to different scanning parameters.

In more detail:
I've done a prospective study with clinical follow-up of subjects with tinnitus. Every subject had to be scanned with 4 rs-fMRI acquisitions within one-year period (T0 – T2 months – T6 months – T12 months). The idea is to compare seed-based fc of the T12-T0 scans, between patients who had good evolution and patients who had bad evolution. Evolution was determined with clinical examination.

Unfortunately, the MRI scanner was replaced during the study. This means that I now have some subjects with all scans acquired on the old machine, some subjects with a mix of data acquired on both the old and new scanner, and some subjects with their scans acquired on the new MRI only.

My question is: can I analyze all subjects regardless of the scanner issue? If yes, how I can account for the scanner effect? Is there a way to account for the MRI machine in the analysis?

Also: is the scanner condition restricting us to perform specific analyses, like seed-based would be less affected than whole-brain ICA for example?
Essentially, what would you recommend as the proper analysis approach for this issue?

Thank you very much for your help,
Marie Detroz, MD, PhD trainee