DTI在脑梗死后视辐射损伤中的应用研究

The Application of Magnetic Resonance Diffusion Tensor Imaging in Optic Radiation Injury After Cerebral Infarction

目的 本研究采用磁共振扩散张量成像（diffusion densor imaging,DTI）技术对脑梗死（cerebral infarction,CH）患者的视辐射（Optic Radiation,OR）进行定量检测,根据OR损伤程度,评估患者预后,指导临床治疗。方法 选择24例首次发病、MRI确诊单侧脑梗死患者,年龄44-75岁,平均59.5岁。DTI检查时间为发病2-7 d（平均4 d）,经治疗1 m后复查DTI;取20例正常人为正常组对比,行DTI扫描,男、女各10例,年龄39-70岁,平均50岁。扫描后,原始数据经PHILIPS EMW 2.6.3.4软件进行后处理,在侧脑室三角层面OR面积最大中央处,测量双侧OR部分各向异性（fractional anisotropy,FA）值、弥散系数（apparent diffusion coefficient,ADC）值。手动绘制感兴趣区（region of interest,ROI）,重建OR并叠加到DWI参考像上,观察OR损伤程度,并将OR损伤类型各分为3组。采用SPSS11.5软件对20例正常组OR-FA、ADC值分别行配对t检验;各OR损伤类型分别行两侧OR-FA、ADC值配对t检验;1 m后复查与发病时患侧OR-FA、ADC值行配对t检（P〈0.05）。结果 正常组OR-FA、ADC值双侧经检验均无明显差异（P〉0.05）;患者组OR-FA、ADC值双侧经检验均有明显差异（P〈0.05）;共15例（62.5%）患者患侧OR完整,未见明显异常;9例（37.5%）患者患侧OR损伤,OR-FA、ADC值明显异常。OR损伤分组双侧OR-FA、ADC值经检验,有统计学差异（P〈0.05）;Ⅲ型因部分重建OR,明显劣于键侧;OR损伤分级越高,损伤越重;患者1 m后与发病时OR-FA、ADC值经检验,有统计学意义（P〈0.05）,说明随着时间,患者视野缺损程度有所减轻。结论 利用DTI可判断脑梗死患者OR受损程度,对评估其视野缺损有重要价值,并有助于临床治疗。

Objective This study attempts to use magnetic resonance diffusion tensor imaging （DTI）to observe the injury of Optic Radiation （OR） after cerebral infarction and estimate the functional outcome. Methods 24 cases of the first onset and diagnosed unilateral infarction patients were selected by MRI,aged 44-75 years,mean 59.5 years old. The duration from the onset to the DTI scan was 2-7 days ;20 normal Volunteers were selected as the normal control group（ 10 males and l0 females, aged 35-70 years old, mean 50 years old）. DTI scan were reviewed after treatment one month later. After DTI scan, the data were processed by the PHILIPS EMW 2.6.3.4 software. The fractional anisotropy （FA） and apparent diffusion coefficient（ADC） values of OR in the lateral triangle plane were measured in both hemispheres. The injury of OR type were divided into three groups. Manually drew ROIs to rebuild the bilateral OR, superimposed to the DWI image, observed the extent damage of OR. SPSS11.5 software for data analyzing. Paired t test for OR-FA and ADC values of bilatera in normal and patient groups were used respectively ;Paired t test for OR-FA and ADC values bilatera of each type of OR respectively;Paired t test for OR-FA and ADC values of ipsilateral after one month to onset. P 〈 0. 05 is statistically significant Results Normal group OR-FA and ADC values were not significantly different after test （ P 〉 0.05 ） ; OR-FA and ADC values in patient group were significantly different after test （ P 〈 0.05 ） ; A total of 15 cases （ 62.5% ） patients with ipsilateral OR complete,no obvious abnormalities ;9 cases （37.5%） patients with ipsilateral OR injury, OR-FA and ADC values showed obvious abnormalities. Each group of OR type, the OR-FA and ADC values were significantly different after test （ P 〈 0.05 ） ; Because part of the reconstruction OR,type Ⅲ is significantly worse than the normal side,the higher grade of OR, the severer the injury;OR-FA and ADC values of ipsilateral after one month to onset was statistically significant （P 〈 0.05 ）. After a period of time,patients with visual field defects abated. Conclusion DTI can be used to observe the injury of OR after cerebral infarction and estimate the functional outcome and is helpful to the clinical treatment.