Study of optic nerve in patients with neuromyelitis optica using diffusion tensor imaging / 中华放射学杂志

ABSTRACT

Objective To explore the diagnostic value of optic diffusion tensor imaging (DTI) in detecting the impairment of optic nerve in neuromyelitis optica (NMO) patients.Methods Conventional MRI and optic DTI were performed in 28 NMO patients and 38 normal controls (NC).Fractional anisotropy (FA) values were measured in the anterior part,middle part and posterior part of intraorbital segment of optic nerve.The patients were classified into 3 groups based on the impairment of vision and visual evoked potential (VEP): monocular impairment (MI) group,10 eyes; biocular impairment (BI) group,36 eyes;and normal-appearing (NA) group,10 eyes.All patients were performed with the evaluation of expanded disability status scale (EDSS).One-way analysis of variance (ANOVA),receiver operating characteristic (ROC) curve,and Spearman correlation analysis were performed among the subgroups of NMO and normal controls.Results There was significantly statistical difference between the four groups (F =43.54,P ＜0.01).Decreased FA values were demonstrated in the MI group (0.29 ±0.08),BI group (0.27 ±0.08),and NA group (0.35 ±0.13) compared with NC (0.45 ±0.07) (P ＜0.01).FA value in BI group was significantly lower than that of NA group(P ＜0.01).Area under curve by ROC analysis in NC vs MI,NC vs BI,NC vs NA,and NC vs NMO was 0.92,0.95,0.74,and 0.91,respectively.The diagnostic sensitivity of ROC was 80％,86％,50％,and 79％,respectively.The diagnostic specificity of ROC was 95％ for the each compared groups.FA value showed no correlation with EDSS for each NMO groups,and showed negative correlation with disease duration for BI group (r =-0.371,P ＜ 0.05).Conclusions Various degrees of optic nerve injuries,indicated by decreased FA value,are present in NMO patients,and optic DTI may be a simple and effective tool for the quantitative evaluation of optic nerve in NMO patients.