Requirements for Coregistration Accuracy in On-Scalp MEG

Tutkimustuotos: Lehtiartikkeli

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@article{c0520a39ae304eab9cc971b6b23478b9,
title = "Requirements for Coregistration Accuracy in On-Scalp MEG",
abstract = "Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use in MEG. In contrast to the SQUID sensors used in current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from the head, enabling the construction of sensor arrays that conform to the shape of an individual’s head. To properly estimate the location of neural sources within the brain, one must accurately know the position and orientation of sensors in relation to the head. With the adaptable on-scalp MEG sensor arrays, this coregistration becomes more challenging than in current SQUID-based MEG systems that use rigid sensor arrays. Here, we used simulations to quantify how accurately one needs to know the position and orientation of sensors in an on-scalp MEG system. The effects that different types of localisation errors have on forward modelling and source estimates obtained by minimum-norm estimation, dipole fitting, and beamforming are detailed. We found that sensor position errors generally have a larger effect than orientation errors and that these errors affect the localisation accuracy of superficial sources the most. To obtain similar or higher accuracy than with current SQUID-based MEG systems, RMS sensor position and orientation errors should be (Formula presented.) and (Formula presented.), respectively.",
keywords = "Coregistration, Magnetoencephalography, Optically-pumped magnetometer",
author = "Rasmus Zetter and Joonas Iivanainen and Matti Stenroos and Lauri Parkkonen",
note = "| openaire: EC/H2020/678578/EU//HRMEG",
year = "2018",
month = "11",
doi = "10.1007/s10548-018-0656-5",
language = "English",
volume = "31",
pages = "931--948",
journal = "Brain Topography, Springer, New York",
issn = "0896-0267",
number = "6",

}

RIS - Lataa

TY - JOUR

T1 - Requirements for Coregistration Accuracy in On-Scalp MEG

AU - Zetter, Rasmus

AU - Iivanainen, Joonas

AU - Stenroos, Matti

AU - Parkkonen, Lauri

N1 - | openaire: EC/H2020/678578/EU//HRMEG

PY - 2018/11

Y1 - 2018/11

N2 - Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use in MEG. In contrast to the SQUID sensors used in current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from the head, enabling the construction of sensor arrays that conform to the shape of an individual’s head. To properly estimate the location of neural sources within the brain, one must accurately know the position and orientation of sensors in relation to the head. With the adaptable on-scalp MEG sensor arrays, this coregistration becomes more challenging than in current SQUID-based MEG systems that use rigid sensor arrays. Here, we used simulations to quantify how accurately one needs to know the position and orientation of sensors in an on-scalp MEG system. The effects that different types of localisation errors have on forward modelling and source estimates obtained by minimum-norm estimation, dipole fitting, and beamforming are detailed. We found that sensor position errors generally have a larger effect than orientation errors and that these errors affect the localisation accuracy of superficial sources the most. To obtain similar or higher accuracy than with current SQUID-based MEG systems, RMS sensor position and orientation errors should be (Formula presented.) and (Formula presented.), respectively.

AB - Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use in MEG. In contrast to the SQUID sensors used in current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from the head, enabling the construction of sensor arrays that conform to the shape of an individual’s head. To properly estimate the location of neural sources within the brain, one must accurately know the position and orientation of sensors in relation to the head. With the adaptable on-scalp MEG sensor arrays, this coregistration becomes more challenging than in current SQUID-based MEG systems that use rigid sensor arrays. Here, we used simulations to quantify how accurately one needs to know the position and orientation of sensors in an on-scalp MEG system. The effects that different types of localisation errors have on forward modelling and source estimates obtained by minimum-norm estimation, dipole fitting, and beamforming are detailed. We found that sensor position errors generally have a larger effect than orientation errors and that these errors affect the localisation accuracy of superficial sources the most. To obtain similar or higher accuracy than with current SQUID-based MEG systems, RMS sensor position and orientation errors should be (Formula presented.) and (Formula presented.), respectively.

KW - Coregistration

KW - Magnetoencephalography

KW - Optically-pumped magnetometer

UR - http://www.scopus.com/inward/record.url?scp=85048900710&partnerID=8YFLogxK

U2 - 10.1007/s10548-018-0656-5

DO - 10.1007/s10548-018-0656-5

M3 - Article

VL - 31

SP - 931

EP - 948

JO - Brain Topography, Springer, New York

JF - Brain Topography, Springer, New York

SN - 0896-0267

IS - 6

ER -

ID: 26393212