Within-subject reproducibility of visual activation patterns with functional magnetic resonance imaging using...

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Medical Imaging

Background:

• Assessing the reliability of functional magnetic resonance imaging (fMRI) is crucial for its clinical application.
• Visual stimulation paradigms are commonly used to probe brain activity.
• Understanding within-subject reproducibility is key for longitudinal studies and clinical diagnostics.

Purpose of the Study:

• To evaluate the within-subject reproducibility of visual brain activation detected by fMRI.
• To determine the reliability of fMRI measurements across different scanning sessions.

Main Methods:

• Ten healthy subjects underwent three fMRI scanning sessions with visual stimulation.
• Data preprocessing included 3D matching, filtering (FWHM 4.0x4.0x5.0 mm), and Bonferroni correction.
• Reproducibility metrics included changes in the center of mass, number of activated voxels, and overlapping activated regions.

Main Results:

• High reproducibility was observed for the number of activated voxels (90% and 88% across sessions).
• Overlap ratios of activated regions were 74% and 64% between sessions.
• Increased filter widths enhanced reproducibility, while significance threshold variations showed an optimal overlap range.

Conclusions:

• fMRI with visual stimulation demonstrates reasonably good within-subject reproducibility on standard clinical systems.
• The technique is suitable for routine clinical use in measuring brain activity.
• Challenges persist in differentiating motion artifacts, repositioning errors, and genuine physiological changes.