Functional and Structural MRI Data Following Transcranial Static Magnetic Stimulation Over the Motor Cortex

This dataset provides multiecho resting-state fMRI, diffusion-weighted imaging (DWI), and high-resolution structural T1-weighted MRI data from right-handed healthy participants.
Each subject participated in two experimental sessions involving real and sham transcranial static-magnetic-field stimulation (tSMS) over the right motor cortex (hand area).
The study employs a double-blind randomized crossover design, enabling direct comparison between stimulation conditions.

This resource facilitates investigation into tSMS-induced changes in functional connectivity, microstructural organization, and motor network dynamics, combining structural, diffusion, and multiecho functional MRI.

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License

Creative Commons Attribution 4.0 International (CC BY 4.0)

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Citation

Caballero-Insaurriaga, J., Pineda-Pardo, J. Á., & Foffani, G. (2025).
Functional and Structural Magnetic Resonance Imaging Data Following Transcranial Static Magnetic Stimulation Over the Motor Cortex (1.0.1) [Data set]. Zenodo.
https://doi.org/10.5281/zenodo.15224957

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Source

https://doi.org/10.5281/zenodo.15224957
Contact: jaime.caballero@unican.es
Institutions: Universidad de Cantabria, Hospital Nacional de Parapléjicos, Universidad Autónoma de Madrid
Funding: Supported by institutional research programs in non-invasive brain stimulation (NIBS)

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Dataset Information

Category	Details
Subjects	Right-handed healthy adults
Design	Randomized double-blind crossover (real vs sham tSMS)
Target Site	Right motor cortex (hand area)
Modalities	Multiecho resting-state fMRI, diffusion-weighted imaging (DWI), high-resolution T1-weighted MRI
Conditions	30-minute real tSMS and sham tSMS sessions
Sessions	Two sessions per subject, separated by one week, same weekday and time
Data Format	NIfTI (.nii/.nii.gz)
Correction Notice (v1.0.1)	Fixed scaling of phase images (now in −π..π range)

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Experimental Details

This dataset includes multiecho resting-state fMRI, Diffusion-Weighted Imaging, and high-resolution structural T1-weighted MRI data acquired from right-handed healthy participants, immediately following 30-minute real and sham tSMS over the right motor cortex (hand region).
Each participant underwent two separate sessions, one with real and one with sham stimulation, performed on separate days but at the same time of day and weekday.
The order of stimulation was randomized and double-blind, ensuring balanced and unbiased comparisons.

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Demographics and Experimental Information

Additional participant details, including demographics (e.g., exact age) and condition-specific experimental notes, are available upon reasonable request to the authors.

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Conversion to NIfTI

All data were converted from native DICOM to NIfTI format using dcm2niix.
File naming corrections and supplemental JSON metadata fields were added using a custom Python script to ensure consistency and completeness.

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Defacing

High-resolution T1-weighted anatomical scans were defaced using FSL’s fsl_deface command.
While this tool reliably removes identifiable facial features, it can slightly reduce the apparent size of the frontal pole (see [Bischoff-Grethe et al., NeuroImage, 2021, doi:10.1016/j.neuroimage.2021.117845]).
To mitigate this, the defacing mask was expanded prior to defacing by combining (binary union) the default mask with a dilated brain mask (7×7×7 voxel kernel).
The brain mask was extracted using FreeSurfer’s mri_synthstrip, and dilation and combination were performed using fslmaths, ensuring full brain coverage for all subjects.

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Scaling of Phase Images

Both multiecho fMRI and DWI were acquired using the CMRR multiband-accelerated EPI pulse sequences (no multiband factor applied due to coil constraints).
Magnitude and phase reconstructions were exported for each dataset.
Native phase images were scaled in the −4096..4094 integer range (as discussed in CMRR Issue #238) and verified by the authors.
Using FSL tools, these were losslessly rescaled to radians (−π..π) by adjusting scl_slope and scl_inter fields in the NIfTI header without altering data type or stored voxel values.

Rescaling formula:
[
\text{phase (radians)} = \frac{x}{4096} \times \pi
]

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Software Versions

Component	Version / Build
CMRR Multiband EPI	R016–R017
dcm2niix	v1.0.20230411 (GCC 12.2.0, Linux x86-64)
Python	3.8.17
FSL	6.0.6.4
FreeSurfer	7.3.2

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File Information

File	Description	Size	Checksum
tSMS_M1R_MRI.zip	MRI data (multi-echo fMRI, DWI, and T1w) for both real and sham stimulation sessions	35.2 GB	md5:2d9f8b9c1ca647dac96619442cffa321

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Keywords

MRI • fMRI • Multi-Echo • Resting-State • Diffusion MRI • DWI • Motor Cortex • tSMS • Transcranial Static Magnetic Field • Non-Invasive Brain Stimulation • NIBS • CMRR • Phase Correction