DOI: 10.5061/dryad.h18931zsq
title: Data from: Three-dimensional infrared scanning: An enhanced approach for spatial registration of probes for neuroimaging

description: Significance: Accurate spatial registration of probes (e.g., optodes and
 electrodes) for measurement of brain activity is a crucial aspect in many
 neuroimaging modalities. It may increase measurement precision and enable
 the transition from channel-based calculations to volumetric
 representations. Aim: This technical note evaluates the efficacy of a
 commercially available infrared three-dimensional (3D) scanner under
 actual experimental (or clinical) conditions and provides guidelines for
 its use. Method: We registered probe positions using an infrared 3D
 scanner and validated them against magnetic resonance imaging (MRI) scans
 on five volunteer participants. Results: Our analysis showed that with
 standard cap fixation, the average Euclidean distance of probe position
 among subjects could reach up to 43 mm, with an average distance of 15.25
 mm [standard deviation (SD) = 8.0]. By contrast, the average distance
 between the infrared 3D scanner and the MRI-acquired positions was 5.69 mm
 (SD = 1.73), while the average difference between consecutive infrared 3D
 scans was 3.43 mm (SD = 1.62). The inter-optode distance, which was fixed
 at 30 mm, was measured as 29.28 mm (SD = 1.12) on the MRI and 29.43 mm (SD
 = 1.96) on infrared 3D scans. Our results demonstrate the high accuracy
 and reproducibility of the proposed spatial registration method, making it
 suitable for both functional near-infrared spectroscopy and
 electroencephalogram studies. Conclusions: The 3D infrared scanning
 technique for spatial registration of probes provides economic efficiency,
 simplicity, practicality, repeatability, and high accuracy, with potential
 benefits for a range of neuroimaging applications. We provide practical
 guidance on anonymization, labeling, and post-processing of acquired
 scans.
description: To estimate the spatial resolution, we registered sensor
 positions using an infrared 3D registration method and performed MRI scans
 on five voluntary participants.
description: # Data from: Three-dimensional infrared scanning: An enhanced approach for
 spatial registration of probes for neuroimaging
 [https://doi.org/10.5061/dryad.h18931zsq](https://doi.org/10.5061/dryad.h18931zsq) We aim to evaluate the efficacy of an infrared 3D scanner as a potential solution for registering neuroimaging probes on the scalp. ## Description of the data and file structure To estimate the spatial resolution, we registered sensor positions using an infrared 3D registration method and performed MRI scans on five voluntary participants. The dataset needs to be unzipped. The data folder contains the infrared 3D scans in an anonymized format (.glb) together with the sensor positions (.pp), labeled in MeshLab. On the anonymized MRI scans, the segmented brain and the position of the nitroglycerin markers were shared (.nii.gz) together with the sensor positions (.json), labeled in Slicer. ## Code/Software We provide the necessary source code for anatomical mapping and integration into the MNE-Python library. The functions can be found in the file 'fnirs_3D_e.py', and the 'main.ipynb' can be run to replicate the calculations from the publication, and also to use the positions in MNE-Python.