The impact of pruning iterations on Arcuate Fasciculus morphometry and diffusion features in right-handed adults

To evaluate the utility of a pruning method in refining tractography and to examine the Arcuate Fasciculus (AF) morphometry and diffusion metrics in right-handed adults. Thirty-two healthy, right-handed adults underwent DTI on a 1.5T MRI system. Q-space diffeomorphic reconstruction was performed on a single-shell DTI dataset, and the AF was automatically tracked. Topology-Informed Pruning (TIP) was applied to reduce false-positive streamlines across varying numbers of iterations. Morphometry and diffusion metrics of the bilateral AF were extracted. The associations between these metrics and the number of iterations were evaluated using correlation analysis. The protocol-specific TIP threshold was identified as the knee point using the Kneedle algorithm. Differences in the morphometry and diffusion metrics of the selection AF tractometry by sex and hemisphere were also examined. A pFDR < 0.05 was considered statistically significant. TIP-based pruning was associated with improved tract delineation through the reduction of spurious streamlines. The number of pruning iterations affected the AF's morphometry and diffusion metrics. The selected TIP threshold was 8, and TIPs greater than 8 yielded stable values with minimal variability. Significant differences between hemispheres were observed in diffusion metrics except quantitative anisotropy (QA). For morphometry metrics, significant differences were identified in the number of tracts, span, and curl (pFDR < 0.05). No significant sex-related differences were found after FDR correction. Pruning iterations affect the visualization of AF in the protocol-specific population of right-handed adults. The number of pruning iterations selected should be carefully determined with full awareness and consideration.