成人视放射磁共振DTI和DTT研究及初步临床应用  

The Initial Clinical Application of MR DTI and DTT in the Adult Optic Radiation

作　　者：宛四海[1] 张雪林[2] 孙鑫[3] 肖新兰[3] 邢海芳 

机构地区：[1]江西省九江市解放军171医院放射科,332000 [2]广州南方医科大学南方医院影像中心,510515 [3]南昌大学第二附属医院磁共振室,330006 [4]广州通用电器公司(中国)医疗集团,510060

出　　处：《临床放射学杂志》2007年第11期1076-1079,共4页Journal of Clinical Radiology

摘　　要：目的应用MR扩散张量成像(DTI)和扩散张量纤维束示踪成像(DTT)研究正常成人视放射的各向异性程度和视放射纤维束的构象特征及其临床应用价值。资料与方法对30名健康志愿者和34例枕叶病变累及视放射的患者进行MR常规及DTI序列检查,重组FA图和三维彩色编码张量图,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。采用扩散张量纤维束追踪软件进行视放射纤维束成像。结果彩色编码张量图均清晰显示视放射,正常视放射的FA值分别为左侧0.509±0.027、右侧0.504±0.028,MD值分别为左侧(0.756±0.049)×10-3mm2/s和右侧(0.734±0.045)×10-3mm2/s,差异均无统计学意义(P(0.05)。DTT显示的视放射纤维束构像和走行特征符合经典神经解剖学研究。20例枕叶陈旧性梗死患者可见视放射继发Wallerian变性,FA明显降低,MD明显增高;3例脑膜瘤患者视放射完整无破坏,呈被推移改变,FA轻度降低,MD轻度增高;3例胶质瘤、1例淋巴瘤、6例转移瘤和1例结核性脑脓肿均显示视放射被破坏、中断,其各向异性消失。结论DTI、DTT可清晰显示视放射纤维束生理和病理条件下的各向异性特征,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。Objective 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）. Materials and Methods DTI and DTT were obtained from 30 healthy volunteer and 34 patients with occipital lobe lesion involving the optic radiation on conventional MRI. Fractional anisotropy （FA） and mean diffusivity （MD） of optic radiation were measured in the color-coded FA tensor imaging. The architecture of the optic radiation fiber tracts was displayed with the software of diffusion tensor fiber tracking. Results In all healthy subjects, the optic radiation could clearly be identified in the color-coded FA tensor imaging. The FA value was 0. 509 ± 0. 027 in left and 0. 504 ± 0. 028 in right, and the MD value was （0.756 ±0.049） × 10^-3 mm^2/s in left and （0.734 ±0.045） × 10^-3 mm^2/s in right respectively. There were no significant differences with the FA or the MD of bilateral optic radiation（P 〉 0.05 ）. Diffusion tensor tractography （DTT） demonstrated the architecture of the optic radiation fiber tracts in accord with classic anatomical studies. The FA value of the optic radiation obviously reduced and MD value obviously increased in chronic infarct of occipital lobe in 20 patients. The optic radiation fiber tracts were intact and shifted in 3 patients of meningioma with the slightly reduced FA value and slightly increased MD value. The optic radiation fiber tracts were destructed and interrupted in other patients including glioma（ 3 cases）, lymphoma（ 1 case）, metastasis tumors（ 6 cases）and tuberculous abscess of brain in 1 case, fractional anisotropy of the optic radiation vanished. Conclusion DTI and DTT can demonstrate the fractional anisotropy of the optic radiation in physiological or pathological condition and it has important significance for diagnosing the lesions involving the optic radiation, which offer methods to study the r

关 键 词：磁共振成像 扩散张量成像 视放射 

分 类 号：R445.2[医药卫生—影像医学与核医学]