Techavipoo Udomchai, Okai Annette F, Lackey John, Shi Jianrong, Dresner Michael A, Leist Thomas P, Lai Song
Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
J Magn Reson Imaging. 2009 Oct;30(4):699-707. doi: 10.1002/jmri.21836.
To develop a practical protocol for diffusion tensor imaging (DTI) of the human optic nerve with echo planar imaging (EPI) geometric distortion correction.
A conventional DTI protocol was modified to acquire images with fat and cerebrospinal fluid (CSF) suppression and field inhomogeneity maps of contiguous coronal slices covering the whole brain. The technique was applied to healthy volunteers and multiple sclerosis patients with and without a history of unilateral optic neuritis. DTI measures and optic nerve tractography before and after geometric distortion correction were compared. Diffusion measures from left and right or from affected and unaffected eyes in different subject cohorts were reported.
The image geometry after correction closely resembled reference anatomical images. Optic nerve tractography became feasible after distortion correction. The diffusion measures from the healthy volunteers were in good agreement with the literature. Statistically significant differences were found in the fractional anisotropy and orthogonal eigenvalues between affected and unaffected eyes in optic neuritis patients with poor recovery. The diffusion measures before and after geometric distortion correction were not significantly different. For cohorts without optic neuritis, the difference between diffusion measures from left and right eyes was not statistically significant.
The proposed technique could provide a practical DTI protocol to study the human optic nerve.
开发一种实用的协议，用于通过回波平面成像（EPI）几何失真校正对人类视神经进行扩散张量成像（DTI）。
对传统的DTI协议进行修改，以获取具有脂肪和脑脊液（CSF）抑制以及覆盖全脑的连续冠状切片的场不均匀性图的图像。该技术应用于健康志愿者以及有或无单侧视神经炎病史的多发性硬化症患者。比较了几何失真校正前后的DTI测量值和视神经纤维束成像。报告了不同受试者队列中左右眼或患眼与未患眼的扩散测量值。
校正后的图像几何形状与参考解剖图像非常相似。失真校正后，视神经纤维束成像变得可行。健康志愿者的扩散测量值与文献报道一致。在恢复较差的视神经炎患者中，患眼与未患眼之间的分数各向异性和正交特征值存在统计学上的显著差异。几何失真校正前后的扩散测量值无显著差异。对于无视神经炎的队列，左右眼扩散测量值之间的差异无统计学意义。
所提出的技术可为研究人类视神经提供一种实用的DTI协议。
