I’m working with the HBN CPAC repository and am trying to understand the difference between a complete pass and a complete artifact threshold. The functional QC threshold is when the median FD is less than or equal to 0.2 and the normalized cross correlation is greater than or equal to 0.8. However, my complete pass clone of the repository has fewer participants than noted (ie, there are fewer than 2213 participants), and I cannot pinpoint where this discrepancy is from.
Thank you for your interest in RBC! Yes, that’s to be expected. The “2,213” value in the flowchart refers only to participants whose functional data passed the fMRI QC thresholds (median FD ≤ 0.2 and NormCrossCor ≥ 0.8). The “complete pass” clone of the repository is more restrictive as it also applies the structural/T1 QC criteria, so it represents the intersection of both functional and structural QC passes. That’s why the number of participants in a complete pass clone ends up being lower than 2213. Separately, the “complete artifact” clone includes participants with both “pass” and “artifact” structural QC labels, while still requiring “pass” functional QC, so it will contain more participants.