磁共振扩散张量成像技术在外伤性视神经病中应用研究

目的 探讨磁共振扩散张量成像技术在评价外伤性视神经病中的作用. 方法选择6例单侧外伤性视神经病患者,采用磁共振扩散张蛩成像技术检测双侧视神经.应用DTV2和Volume One 1.44软件测量视神经的部分各向异性值、平均表观扩散系数,并进行损伤眼和正常眼的自身对比;应用神经白质纤维柬追踪技术显示视神经的空间完整性和连续情况.结果 所有患者眶内段视神经显示良好,2例患者双侧管内段显示欠佳.6例患者损伤眼眶内段视神经部分各向异性平均值较正常眼明显下降,分别为0.244±0.067和0.452±0.053,差异有统计学意义(P=0.000);平均表观扩散系数平均值较正常眼明显上升,分别为(1.417±0.121)×10<'-3>mm<'2>/s和(1.087±0.118)×10<'-3>mm<'2>/s,差异有统计学意义(P=0.003).4例患者可以获得用于评估双侧视神经空间连接情况的扩散张量纤维束成像图,损伤眼和正常眼之间存在明显差异.结论磁共振扩散张量成像技术能够为评估外伤性视神经病的视神经纤维病理情况提供有价值的信息.

Diffusion tensor magnetic resonance imaging in traumatic optic neuropathy

Objective To study the value of diffusion tensor magnetic resonance imaging (DT-MRI) in evaluating traumatic optic neuropathy. Methods DT-MRI data of bilateral optic nerve were acquired in 6 patients with unilateral traumatic optic neuropathy. Volume One 1.44 and DTV2 softwares were employed to measure the fraction anisotropy (FA) and average apparent diffusion coefficient (ADC), and to self-compare between the injured and intact optic nerves. The architecture of the optic radiation fiber tracts were displayed with the software of diffusion tensor fiber tracking. Results All of the infraorbital segments of optic nerves were well demonstrated, with suboptimal intracanalicular portion in 2 patients. The average FA of intraorbital optic nerve in 6 patients: the injured side was 0.244±0.067 and the uninjured side was 0.452±0.053 (P=0.000);FA of the injured side obviously decreased. The average value of ADC: the injured side was (1.417±0.121)×10<'-3> mm<'2>/s and the uninjured side was (1.087±0.118)×10<'3> mm<'2>/s (P=0.003);the value of ADC of the injured side obviously increased. Statistically significant differences were noted between the injured side and the uninjured side. The spacial integralities and connected situations of the nerves could be obtained in 4 patients with significant differences between the injured and the uninjured sides. Conclusion DT-MRI can provide useful pathological information in evaluating traumatic optic neuropathy.