Sensor-Head Distance and Signal Strength in Whole-Head Magnetoencephalography: Report of 996 Patients With Epilepsy.
Journal
Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
ISSN: 1537-1603
Titre abrégé: J Clin Neurophysiol
Pays: United States
ID NLM: 8506708
Informations de publication
Date de publication:
22 Aug 2024
22 Aug 2024
Historique:
medline:
23
8
2024
pubmed:
23
8
2024
entrez:
23
8
2024
Statut:
aheadofprint
Résumé
Although the sensor-to-head distance is theoretically known to affect the signal strength in magnetoencephalography (MEG), these values have not been reported for a whole-head MEG system in a large population. We measured the distance and signal strength in 996 patients with epilepsy. The MEG sensor array consisted of 102 measurement sites, each of which had two gradiometers and one magnetometer. The sensor-head distance was defined as the minimum distance between each site and a set of digitized scalp points. For the signal strength, we calculated the root-mean-square of the signal values in each sensor over a recording of 4 minutes. For analyses at the individual and sensor levels, these values were averaged over the sensors and patients, respectively. We evaluated the correlation between distance and signal strength at both individual and sensor levels. At the sensor level, we investigated regional differences in these measures. The individual-level analysis showed only a weak negative correlation between the sensor-head distance and the signal strength. The sensor-level analysis demonstrated a considerably negative correlation for both gradiometers and magnetometers. The sensor-head distances showed no significant differences between the regions, whereas the signal strength was higher in the temporal and occipital sensors than in the frontal and parietal sensors. Sensor-head distance was not a definitive factor for determining the magnitude of MEG signals in individuals. Yet, the distance is important for the signal strength at a sensor level. Regional differences in signal strength may need to be considered in the analysis and interpretation of MEG.
Identifiants
pubmed: 39177533
doi: 10.1097/WNP.0000000000001114
pii: 00004691-990000000-00167
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Subventions
Organisme : NIH HHS
ID : S10RR014978
Pays : United States
Organisme : NIH HHS
ID : S10OD030469
Pays : United States
Organisme : NIH HHS
ID : R01NS069696
Pays : United States
Organisme : NIH HHS
ID : R01DC016765
Pays : United States
Organisme : NIH HHS
ID : P41EB015896
Pays : United States
Organisme : NIH HHS
ID : P41EB030006
Pays : United States
Informations de copyright
Copyright © 2024 by the American Clinical Neurophysiology Society.
Déclaration de conflit d'intérêts
The authors have no funding or conflicts of interest to disclose.
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