Hemodynamic response function parameters obtained from resting-state functional MRI data in soldiers with trauma.

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Psychiatry

Background:

• Functional magnetic resonance imaging (fMRI) measures brain activity indirectly through the hemodynamic response function (HRF).
• HRF shape varies significantly across brain regions and individuals due to neural and non-neural factors.
• Characterizing HRF parameters (e.g., time-to-peak, full-width at half-maximum) is essential for precise fMRI data interpretation.

Purpose of the Study:

• To provide voxel-wise data on three key HRF parameters.
• To investigate HRF variability in U.S. Army soldiers diagnosed with posttraumatic stress disorder (PTSD) and/or comorbid mild traumatic brain injury (mTBI).
• To offer a dataset valuable for understanding HRF variability's impact on fMRI analysis, particularly resting-state functional connectivity.

Main Methods:

• Acquired fMRI data from 87 U.S. Army soldiers.
• Included cohorts with PTSD, comorbid PTSD and mTBI, and healthy combat controls.
• Calculated three HRF parameters (response height, time-to-peak, full-width at half-max) at each voxel.

Main Results:

• HRF parameters were quantified across all voxels for each participant group.
• The dataset enables detailed examination of HRF variability.
• Findings support further research into HRF's influence on fMRI connectivity.

Conclusions:

• The presented data offers a comprehensive resource for HRF parameter characterization in specific military populations.
• This dataset is critical for advancing the accuracy of fMRI analyses, especially in studying resting-state functional connectivity.
• Understanding individual HRF differences is key to refining neuroimaging techniques for conditions like PTSD and mTBI.