[Preliminary study of DTI on cerebral white matter micro-structure of patients with idiopathic olfactory loss]

To investigate the cerebral white matter micro-structure in patients with idiopathic olfactory loss using diffusion tensor imaging (DTI).

Sixteen patients with idiopathic olfactory loss and sixteen normal subjects matched by age and sex were recruited in this study. Sniffin'Stick olfactory test was performed to evaluate the olfactory function of all subjects. We acquired diffusion tensor images with an echo planar imaging (EPI) sequence from all subject on a 3T scanner. The fractional anisotropy (FA) images were performed using DTI-studio, and bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex adjacent white matter and Capsula interna were delineated as the region of interesting (ROI), the FA for each ROI was calculated. Independent sample t test analysis was used to compare the FA value of all ROIs between the controls and patients. In addition, correlation analysis between FA value and MMSE score in patients were conducted.

Compared with the controls, patients showed significantly decreased FA value in the adjacent white matter of bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex (P<0.05). There is no significant difference of FA value in bilateral Capsula interna between two groups (P>0.05).

The patients with idiopathic olfactory loss show the damage of white matter micro-structure in the olfactory center, which could be important for the pathogenesis study and early intervention of idiopathic olfactory loss.