A Preliminary Investigation Report on Using Probabilistic Fiber Tractography to Track Human Auditory Pathways

Abstract Background Diffusion tensor imaging (DTI) is currently the only non-invasive way to map subcortical white matter tractography. Radiologists and neurologists often fail to reconstruct the complex auditory pathways when applying the most commonly used approach, deterministic fiber tracking, because this method is limited in spatial and angular resolution. A different fiber-tracking method involving a probabilistic approach could partly compensate for these limitations. Objective To investigate the efficiency and potential usefulness of the probabilistic fiber-tracking method in depicting human auditory pathways in both healthy individuals and unilateral vestibular schwannoma (VS) patients. Method Eight healthy volunteers and 14 patients with unilateral VS were scanned with DTI. Probabilistic fiber tracking of the auditory pathways for each subject was carried out using FSL software. The tracking rate, reliability of results, fiber volume, fiber length, and fractional anisotropy (FA) values were considered in assessing the reliability and sensitivity of this method. Fiber length and fiber volume and were analyzed separately for the healthy group and VS group. Results The results showed good tracking sensitivity and consistency in both healthy subjects and patients with VS. For fiber length, the 8 healthy subjects exhibited significant between-sides differences whereas the 14 VS patients showed no such difference. For fiber volume, there was a statistically significant difference between groups, as the VS patients displayed a smaller fiber volume on the non-tumor side. FA values revealed no significant autologous or between-group differences. These results match those of previous anatomical and neurological studies. Conclusion The auditory pathway can be depicted well by the probabilistic fiber-tracking method. This method can compensate in part for the weaknesses of the widely used deterministic tractography approach in depicting fine and complicated subcortical fibers.