@dpat @effigies I'm traveling so just looking on the phone, and can't cross-check our #fMRIPrep versions yet. But a few thoughts anyway:
- are these CMRR multiband sequences? If so, have you checked the SBRef images as well as the fmaps?
- We're collecting an #fMRI dataset with 3mm iso voxels, CMRR MB4, and haven't had trouble
- are all the person's runs in a session distorted, or just some? If some, compare the fmaps, etc between good and bad runs.
Good luck!
Thanks so much to both of you for your feedback.
**All affected or only some?**
Jo, I'm inquiring with the relevant labs whether it is all subjects or only some that are affected. Anecdotally, my conversations indicate that at the very least some participants are affected more than others.
As for multiple runs in one session: yes, in the example I have with 4 runs, all are affected.
**MB acceleration**
It looks to me like the run from the good lab had multiband acceleration while neither of the labs that had problems were using multiband. I've attached their protocols
Pest protocol (bad example):
https://www.dropbox.com/scl/fi/adohy8oiqcrv7fkgheg8d/pest.pdf?rlkey=b35u17bvtbk3q1p8fmjt5b0eg&dl=0
See See page 28-29 FMR Accel mode none
CAM protocol (good example): https://www.dropbox.com/scl/fi/1dez31jvztq1hgvs6tty9/cam.pdf?rlkey=ou5oihy9lnb3skln8sjzu7df8&dl=0
See pages 10-11 RS-FMRI-MB-high_resolution Accel factor 3.
Dianne Patterson
Jo Etzel