Charles B Malpas1,2, Tim Silk3, and Marc Seal3
1Developmental Imaging, Murdoch Children's Research Institute, Melbourne, Australia, 2Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia, 3Murdoch Children's Research Institute, Melbourne, Australia
Multi-scale entropy
(MSE) quantifies the complexity of a time-series. Regular, predictable
time-series have low MSE, while random time-series have high MSE. In this
study, we compared conventional and multi-band acquisitions of resting-state
BOLD images to determine their impact on MSE. We found that multi-band
acquisitions produced lower MSE compared to non-multi-band acquisition. The
effect did not persist when the number of volumes acquired was taken into
consideration, suggesting that it is the number of volumes, and not multi-band
acquisition per se that influences
MSE. The implications for biomarker use are discussed, with particular emphasis
on the ageing brain.
