Nonsteady state - can we squeeze some IQMs out of it?

[oesteban]

Following up on a very ancient suggestion by Chris G. (#320), and his reference there http://spinthatresonates.blogspot.com/2016/12/first-few-images-are-brighter-than-rest.html, it'd be interesting to explore how much nonsteady state tells you about the quality of the image.

I'd say this is more of a worry for fMRIPrep to report and then in analysis to be considered as a potential confounder, but I did not want to close the issue without hearing opinions.