TY - JOUR

T1 - Effect of motion artifacts and their correction on near-infrared spectroscopy oscillation data

T2 - a study in healthy subjects and stroke patients

AU - Selb, Juliette

AU - Yücel, Meryem A

AU - Phillip, Dorte

AU - Schytz, Henrik W

AU - Iversen, Helle K

AU - Vangel, Mark

AU - Ashina, Messoud

AU - Boas, David A

PY - 2015/5

Y1 - 2015/5

N2 - Functional near-infrared spectroscopy is prone to contamination by motion artifacts (MAs). Motion correction algorithms have previously been proposed and their respective performance compared for evoked rain activation studies. We study instead the effect of MAs on "oscillation" data which is at the basis of functional connectivity and autoregulation studies. We use as our metric of interest the interhemispheric correlation (IHC), the correlation coefficient between symmetrical time series of oxyhemoglobin oscillations. We show that increased motion content results in a decreased IHC. Using a set of motion-free data on which we add real MAs, we find that the best motion correction approach consists of discarding the segments of MAs following a careful approach to minimize the contamination due to band-pass filtering of data from "bad" segments spreading into adjacent "good" segments. Finally, we compare the IHC in a stroke group and in a healthy group that we artificially contaminated with the MA content of the stroke group, in order to avoid the confounding effect of increased motion incidence in the stroke patients. After motion correction, the IHC remains lower in the stroke group in the frequency band around 0.1 and 0.04 Hz, suggesting a physiological origin for the difference. We emphasize the importance of considering MAs as a confounding factor in oscillation-based functional near-infrared spectroscopy studies.

AB - Functional near-infrared spectroscopy is prone to contamination by motion artifacts (MAs). Motion correction algorithms have previously been proposed and their respective performance compared for evoked rain activation studies. We study instead the effect of MAs on "oscillation" data which is at the basis of functional connectivity and autoregulation studies. We use as our metric of interest the interhemispheric correlation (IHC), the correlation coefficient between symmetrical time series of oxyhemoglobin oscillations. We show that increased motion content results in a decreased IHC. Using a set of motion-free data on which we add real MAs, we find that the best motion correction approach consists of discarding the segments of MAs following a careful approach to minimize the contamination due to band-pass filtering of data from "bad" segments spreading into adjacent "good" segments. Finally, we compare the IHC in a stroke group and in a healthy group that we artificially contaminated with the MA content of the stroke group, in order to avoid the confounding effect of increased motion incidence in the stroke patients. After motion correction, the IHC remains lower in the stroke group in the frequency band around 0.1 and 0.04 Hz, suggesting a physiological origin for the difference. We emphasize the importance of considering MAs as a confounding factor in oscillation-based functional near-infrared spectroscopy studies.

KW - Artifacts

KW - Biological Clocks

KW - Brain

KW - Brain Mapping

KW - Humans

KW - Image Enhancement

KW - Image Interpretation, Computer-Assisted

KW - Motion

KW - Oxygen Consumption

KW - Reproducibility of Results

KW - Sensitivity and Specificity

KW - Spectroscopy, Near-Infrared

KW - Stroke

U2 - 10.1117/1.JBO.20.5.056011

DO - 10.1117/1.JBO.20.5.056011

M3 - Journal article

C2 - 26018790

VL - 20

JO - Journal of Biomedical Optics

JF - Journal of Biomedical Optics

SN - 1083-3668

IS - 5

M1 - 56011

ER -