Removing motion and physiological artifacts from intrinsic BOLD fluctuations using short echo data

Autor: Molly G. Bright, Kevin Murphy
Rok vydání: 2013
Předmět:
Zdroj: Neuroimage
ISSN: 1053-8119
DOI: 10.1016/j.neuroimage.2012.09.043
Popis: Differing noise variance across study populations has been shown to cause artifactual group differences in functional connectivity measures. In this study, we investigate the use of short echo time functional MRI data to correct for these noise sources in blood oxygenation level dependent (BOLD)-weighted time series. A dual‐echo sequence was used to simultaneously acquire data at both a short (TE = 3.3 ms) and a BOLD-weighted (TE = 35 ms) echo time. This approach is effectively “free,” using dead-time in the pulse sequence to collect an additional echo without affecting overall scan time or temporal resolution. The proposed correction method uses voxelwise regression of the short TE data from the BOLD-weighted data to remove noise variance. In addition to a typical resting state scan, non-compliant behavior associated with patient groups was simulated via increased head motion or physiological fluctuations in 10 subjects. Short TE data showed significant correlations with the traditional motion-related and physiological noise regressors used in current connectivity analyses. Following traditional preprocessing, the extent of significant additional variance explained by the short TE data regressors was significantly correlated with the average head motion across the scan in the resting data (r2 = 0.93, p
Highlights ► Short echo time fMRI data reflect head motion and physiological noise sources. ► Variance removed by short TE regressors correlates with total scan motion. ► Regressing short TE data from resting state BOLD data reduces artifactual correlations. ► This method could improve group comparisons of resting state data.
Databáze: OpenAIRE