Effect of Phase-Encoding Direction on Gender Differences: A Resting-State Functional Magnetic Resonance Imaging...

Area of Science:

• Neuroimaging
• Neuroscience
• Brain Imaging

Background:

• Gender differences in brain function are noted but not well-established.
• Echo-planar imaging (EPI) is common in fMRI but susceptible to distortions.
• The impact of EPI phase-encoding (PE) direction on gender-related findings is understudied.

Purpose of the Study:

• To investigate how PE direction affects the detection of gender differences in brain activity.
• To clarify the influence of anterior-to-posterior (AP) versus posterior-to-anterior (PA) PE directions on fMRI outcomes.
• To assess the interaction between gender and PE direction in spontaneous brain activity.

Main Methods:

• Collected resting-state fMRI data from 113 healthy participants using AP and PA PE directions.
• Calculated spontaneous brain activity indices: ALFF, fALFF, ReHo, DC, and FC.
• Performed group comparisons: PE direction, gender, and their interaction.

Main Results:

• Significant differences in brain activity indices were observed between AP and PA PE directions.
• Multiple brain regions showed gender differences across various indices.
• An interaction effect between gender and PE direction was found in specific brain regions, including the middle frontal gyrus and cerebellum.

Conclusions:

• PE direction partially influences gender differences in resting-state fMRI.
• Documenting and carefully selecting PE direction is essential for future fMRI research.
• Findings highlight the importance of considering technical parameters in neuroimaging studies of gender differences.