Diffusion tensor imaging of the auditory pathway in sensorineural hearing loss: changes in radial diffusivity and diffusion anisotropy.
OBJECTIVE
To prospectively compare diffusion tensor imaging (DTI) measures of axial diffusivity (lambda parallel), radial diffusivity (lambda perpendicular), mean diffusivity (MD), and fractional anisotropy (FA) along the auditory pathway of patients with sensorineural hearing loss (SNHL) and normal controls.


METHODS
In 37 individuals with SNHL and 10 healthy controls, two regions of interest (ROIs) positioned along the auditory pathway-the lateral lemniscus (LL) and the inferior colliculus (IC)-were investigated bilaterally using diffusion tensor imaging at 3 T. SNHL patients were divided into three groups: patients with bilateral hearing loss, patients with unilateral hearing loss, and patients with partial hearing loss. DTI measures (lambda parallel, lambda perpendicular, MD, FA) of both ROIs were determined in all subjects.


RESULTS
The FA value was reduced and the lambda perpendicular was increased both at the lateral lemniscus and the inferior colliculus of patients with SNHL compared with controls. Similar changes were seen between the ipsilateral and contralateral LL and IC for patients of unilateral profound hearing loss. No changes were observed in any other parameters.


CONCLUSIONS
In SNHL patients DTI showed a high radial diffusivity that consequently led to a decreased fractional anisotropy in the LL and the IC.
Lin
YuChun
Y
Department of Diagnostic Radiology, Chang Gung Memorial Hospital, and Department of Medical Imaging and Radiological Science, Chang Gung University, Taipei, Taiwan.
Wang
JiunJie
J
Wu
CheMing
C
Wai
YauYau
Y
Yu
JenFang
J
Ng
ShuHang
S
D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D001306:Auditory Pathways / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity