Hybrid ultra-low-field MRI and magnetoencephalography system based on a commercial whole-head neuromagnetometer.
Ultra-low-field MRI uses microtesla fields for signal encoding and sensitive superconducting quantum interference devices for signal detection. Similarly, modern magnetoencephalography (MEG) systems use arrays comprising hundreds of superconducting quantum interference device channels to measure the magnetic field generated by neuronal activity. In this article, hybrid MEG-MRI instrumentation based on a commercial whole-head MEG device is described. The combination of ultra-low-field MRI and MEG in a single device is expected to significantly reduce coregistration errors between the two modalities, to simplify MEG analysis, and to improve MEG localization accuracy. The sensor solutions, MRI coils (including a superconducting polarizing coil), an optimized pulse sequence, and a reconstruction method suitable for hybrid MEG-MRI measurements are described. The performance of the device is demonstrated by presenting ultra-low-field-MR images and MEG recordings that are compared with data obtained with a 3T scanner and a commercial MEG device.
Department of Biomedical Engineering and Computational Science, Aalto University School of Science, Espoo, Finland. panu.vesanen@aalto.fi
Panu T
PT
Vesanen
Jaakko O
JO
Nieminen
Koos C J
KC
Zevenhoven
Juhani
J
Dabek
Lauri T
LT
Parkkonen
Andrey V
AV
Zhdanov
Juho
J
Luomahaara
Juha
J
Hassel
Jari
J
Penttilä
Juha
J
Simola
Antti I
AI
Ahonen
Jyrki P
JP
Mäkelä
Risto J
RJ
Ilmoniemi
D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D001931:Brain Mapping / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D015225:Magnetoencephalography / Q000295:instrumentation*; D060306:Magnetometry / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique / Q000295:instrumentation*; D018511:Systems Integration