Diffusion Tensor Imaging in Unilateral Sensorineural Hearing Loss reveals Microstructural Alterations of the Auditory nerve

Introduction Diffusion tensor imaging (DTI) is a MR-based neuroimaging method that enables to visualize neural pathways and to analyze their microstructure by means of different diffusion parameters. While DTI is an important tool in neuroradiological research, only few DTI studies in ENT have been published so far.

Methods 22 patients with unilateral sensorineural hearing loss and 18 healthy, normal-hearing subjects were included in this study. We obtained both structural MRI images and diffusion weighted images with a voxel size of 1,5x1,5x1,5mm3 and diffusion encoding in 30 directions on a 3 Tesla MRI Scanner. After the systematic definition of regions of interest (ROI), the auditory nerve was visualized successfully in all subjects. Subsequently, diffusion parameters, namely fractional anisotropy (FA), trace, axial and radial diffusivity, were calculated along its course.

Results Due to relatively high resolution of the obtained DTI scans we were able to visualize the auditory nerve in both groups and to delineate asymmetries in its microstructure. In patients with unilateral sensorineural hearing loss, alterations of diffusion parameters and thus of the microstructure of the auditory nerve were found.

Conclusions Various alterations of diffusion parameters of the auditory nerve indicate changes of its neural microstructure in unilateral hearing loss. DTI therefore presents a new opportunity to investigate neural pathways in diseases of the audiovestibular system.

Publication History

Article published online:
12 May 2023