Task-free connectivity analyses have emerged as a powerful tool in functional neuroimaging. Because the cross-correlations that underlie connectivity measures are sensitive to distortion of time-series, here we used a novel dynamic phantom to provide a ground truth for dynamic fidelity between blood oxygen level dependent (BOLD)-like inputs and fMRI outputs. We found that the de facto quality-metric for task-free fMRI, temporal signal to noise ratio (tSNR), correlated inversely with dynamic fidelity; thus, studies optimized for tSNR actually produced time-series that showed the greatest distortion of signal dynamics. Instead, the phantom showed that dynamic fidelity is reasonably approximated by a measure that, unlike tSNR, dissociates signal dynamics from scanner artifact. We then tested this measure, signal fluctuation sensitivity (SFS), against human resting-state data. As predicted by the phantom, SFS-and not tSNR-is associated with enhanced sensitivity to both local and long-range connectivity within the brain's default mode network.
CITATION STYLE
DeDora, D. J., Nedic, S., Katti, P., Arnab, S., Wald, L. L., Takahashi, A., … Mujica-Parodi, L. R. (2016). Signal fluctuation sensitivity: An improved metric for optimizing detection of resting-state fMRI networks. Frontiers in Neuroscience, 10(MAY). https://doi.org/10.3389/fnins.2016.00180
Mendeley helps you to discover research relevant for your work.