title: Safety of EEG-fMRI recordings in newborn infants at 3T: a study using a baby-size phantom.
abstract: OBJECTIVE
  We aimed to study EEG electrode temperatures during MRI recordings using a neonatal-size phantom to establish the safety of neonatal EEG-MRI.
  
  
  METHODS
  We constructed a phantom set-up for co-registration of EEG and MRI measurements with newborn size configurations. The set-up consisted of a spherical glass phantom fitted with a customised MRI-compatible 64-channel EEG cap and EEG amplifier. Temperatures were recorded during and after five different scanning sequences (two T2∗ sensitised BOLD fMRI, one T1-weighted and two T2-weighted spin echo) in five electrode locations using a thermistor that was integrated into the electrode housing. A temperature increase >4°C was defined a priori as the safety limit.
  
  
  RESULTS
  During fMRI and T1 sequences, none of the electrodes showed meaningful temperature changes. Only one MRI sequence (T2 with Max turbo factor 25; SAR 89%) caused temperature increase in one electrode (Fpz; +4.1°C) that slightly exceeded our predefined safety limit, while the conventional T2 sequence was within safety limits (up to +1.7°C).
  
  
  CONCLUSIONS
  Co-registration of EEG and fMRI can be considered safe in babies with respect to electrode heating, which is the primary safety concern.
  
  
  CONCLUSIONS
  The present findings open up a possibility to commence studies where EEG and MRI/fMRI are co-registered in human babies. Such studies hold significant promise of a better understanding of the early development of brain function and neurovascular coupling.
authors.affiliation: Department of Children's Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland. Electronic address: sampsa.vanhatalo@helsinki.fi.
authors.forename: Sampsa
authors.initials: S
authors.lastname: Vanhatalo
authors.affiliation: Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Aiman
authors.initials: A
authors.lastname: Alnajjar
authors.affiliation: Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Vinh T
authors.initials: VT
authors.lastname: Nguyen
authors.affiliation: Department of Children's Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Paul
authors.initials: P
authors.lastname: Colditz
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Fransson
mesh_terms: D016477:Artifacts; D001921:Brain / Q000502:physiology*; D002138:Calibration; D004566:Electrodes; D004569:Electroencephalography / Q000295:instrumentation*; D004867:Equipment Design; D004869:Equipment Safety; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D010100:Oxygen / Q000097:blood; D019047:Phantoms, Imaging; D013696:Temperature
chemical_list: D010100:Oxygen
keywords: High-density EEG; Neonatal EEG; Neonatal neurophysiology; Newborn; Resting state networks; fMRI–EEG co-registration