成人视放射弥散张量纤维束示踪成像的临床应用研究

摘要

Objective It has been difficult to obtain anatomic and functional information about the optic radiation on conventional imaging method. To investigate the degree of anisotropy and the architecture of the optic radiation fiber tracts in healthy and pathological condition with MR diffusion tensor imaging( DTI) and diffusion tensor tractography ( DTT) . Methods The data was obtained from 20 people without lesion in the optic radiation and 24 patients with lesion involving the optic radiation on conventional MRI. Fractional anisotropy ( FA) and mean diffusivity (MD) value of optic radiation were measured. The architecture of the optic radiation fiber tracts was displayed with the software of diffusion tensor fiber tracking. Results There were no significant diferences with the FA or the MD of bilateral optic radiation ( P > 0. 05 ) in normal people. The FA value of the optic radiation obviously reduced and MD value obviously increased and the optic radiation fiber tracts were destructed in 24 patients. Conclusions As a new method to study the relationship between visual function and optic radiation, DTI and DTT can demonstrate the fractional anisotropy of the optic radiation in physiological or pathological condition and has important significance for diagnosing the lesions involving the optic radiation%目的 常规的影像手段对视放射纤维束的成像、分析缺乏特异性,为了弥补常规影像检查的不足,应用弥散张量成像(DTI)和弥散张量纤维束示踪成像(DTT)研究成人视放射的各向异性程度和视放射纤维束的构象特征.方法 对20例正常视放射和24例视放射区域病变的患者进行MR常规及DTI序列检查,分别测量双侧视放射区的部分各向异性(FA)值和平均扩散率(MD)值,采用弥散张量纤维束追踪软件进行视放射纤维束成像.结果 正常视放射的FA值、MD值左右侧差异均无统计学意义(P>0.05).24例肿瘤患者可见患侧视放射被破坏中断,FA值明显下降、MD值明显升高.结论 DTI和DTT可清晰显示视放射纤维束生理和病理的各向异性和构象特征,对提高视放射病变的显示和诊断具有重要意义,为了解视功能与视放射之间的关系提供了新的研究手段.