title: Diffusion tensor imaging of optic nerve and optic radiation in primary chronic angle-closure glaucoma using 3T magnetic resonance imaging.
abstract: OBJECTIVE
  To evaluate the value of quantitative diffusion tensor imaging (DTI) in assessing the axonal and myelin damage of the optic nerves and optic radiations in patients with chronic primary angle-closure glaucoma (PACG) by using high-field magnetic resonance (MR) imaging (3T).
  
  
  METHODS
  Twenty patients with bilateral chronic PACG and twenty age- and sex matched disease-free control subjects were enrolled. Conventional MRI and DTI were performed on all subjects using 3T MR scanner. Mean diffusivity (MD), fractional anisotropy (FA), axial diffusivities (AD) and radial diffusivities (RD) of each optic nerve and each optic radiation were measured by using post-processing software of DTI studio 2.3, and then compared between left eyes and right eyes and between patients group and control group. The paired-sample t- test were used.
  
  
  RESULTS
  There was no abnormality in the shape and signal intensity of the optic nerves and optic radiations in patients group and control group on the conventional MRI. No significant differences were observed in the FA, MD, AD and RD between the right and left optic nerves and optic radiations within patients group and control group (P>0.05). The optic nerves and optic radiations of patients with chronic PACG, as compared with control subjects, had significantly higher MD, AD, RD and significantly lower FA (P<0.05).
  
  
  CONCLUSIONS
  The diffusivity of optic nerves and optic radiations in chronic PACG group showed abnormal and diffusivity parameters could be used markers of axonal and myelin injury in glaucoma.
authors.affiliation: Department of Radiology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
authors.forename: Qiu-Juan
authors.initials: QJ
authors.lastname: Zhang
authors.affiliation: Department of Radiology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Radiology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
authors.forename: Zhi-Lan
authors.initials: ZL
authors.lastname: Bai
authors.affiliation: Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
authors.forename: Bai-Chao
authors.initials: BC
authors.lastname: Ren
authors.affiliation: Department of Radiology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Li
keywords: chronic; diffusion tensor imaging; magnetic resonance imaging; optic nerve and optic radiation; primary angle-closure glaucoma