T1w Motion Quality Control

Motion quality control (QC) for structural T1 scans

By Saashi A. Bedford, used in her paper: Bedford, S. et al, (2019). Large-scale analyses of the relationship between sex, age and intelligence quotient heterogeneity and cortical morphometry in autism spectrum disorder. Molecular Psychiatry https://www.nature.com/articles/s41380-019-0420-6.

This guide will help you rate your scans for the amount of motion present, and decide which ones to include in your analysis.

4 point scale:

Perfect/clean scan
Slight motion (slight ringing or blurring, and/or only in a confined area)
Obvious motion (obvious or bad ringing or blurring, and/or over whole brain)
Very bad motion -- (this will be very obvious, eg. can’t even tell it’s a brain) -- (the difference between 3 and 4 is not that important, because they are both a fail. 4 is more just to highlight if it’s a really really terrible scan)

Notes:

Can give .5s (eg 1.5, 2.5) if not sure.
I try to avoid this but it’s often hard to decide - it can also be good to have a detailed account of the quality of each scan
- eg. 1.5 is if it is almost perfect but not quite.
The cut off you use is up to you; for a pretty strict cut off, I would recommend including anything in the analysis that is < 2 (ie. 1.5 or 1); or 2 and below if you are being a bit less strict.
If in doubt, a good question to keep in mind: “would you be embarrassed to show this scan in your supplemental material?”
- (if yes, I usually go for at least 2.5 or 3) - I find this helps!
It’s important (and helpful) to look at all views of the scan; often rings are easier to see in the coronal view; sometimes they will be barely visible in the sagittal but obvious in coronal view
Screenshot examples included below, but it is a bit hard to tell from the image, you need to scroll through all slices of the scan and look at different views.