Comparative Performance Assessment of EPI Distortion-Correction Software for Enhanced Accuracy in Submillimetre fMRI at 7T

Motivation: Several software packages offer the blip-up/blip-down correction routine to address geometric distortions in EPI for fMRI. However, comparative assessments of their performance still remain largely unexplored, making it difficult to determine the optimal configuration. Goal(s): This work employs FSL, AFNI and ANTs to investigate performance differences in distortion correction, potentially resulting in submillimetre fMRI analysis at 7T. Approach: The performance of the three software packages was evaluated using various criteria: spatial resolution degradation, functional mapping accuracy and histogram distribution. Results: All software packages effectively corrected geometric distortions. However, ANTs demonstrated the least spatial resolution degradation, subsequently resulting in greater accuracy in functional mapping. Impact: This study presents comparative performance assessments of EPI distortion correction software packages (FSL, AFNI, and ANTs) for submillimetre fMRI at 7T. While all methods effectively reduced distortions, ANTs demonstrated the least spatial resolution degradation and higher accuracy in functional mapping.