3D printed pediatric head phantom for assessing deep epileptic sources localization

Assessing the localization accuracy of electric and magnetic source imaging (ESI/MSI) for deep brain sources using a 3D-printed head phantom.

We developed a realistic pediatric head phantom preserving brain, skull, and scalp properties with implanted sources in clinically relevant deep brain locations. Localization accuracy of ESI/MSI was assessed across varying noise levels using dipole fitting and dynamic statistical parametric mapping (dSPM).

The phantom generated realistic MEG and EEG data resembling actual epilepsy patient recordings. MSI showed superior accuracy to ESI for the deep tangential insular source (dipole: ∼17 vs. ∼33 mm; dSPM: ∼24 vs. ∼32 mm). While ESI-ECD localized some radial sources well (e.g. ∼9 mm for brainstem), its dSPM struggled to localize deep sources (e.g. insula and amygdala). Both modalities found the radial thalamus source most challenging to localize.

MSI outperformed ESI for localizing deep tangential sources; yet, both techniques struggled to localize deep radial sources. For point-like sources, dipole fitting delivered the highest accuracy (∼9 mm, ESI for brainstem), whereas averaged dSPM was superior for sources with distributed-source behavior (∼13 mm, MSI for orbital gyrus).

3D Printed realistic head phantoms can aid assessing the accuracy of ESI/MSI and selecting appropriate methods for different clinical scenarios.