弥散张量成像（DTI）在颅脑高级别胶质瘤中的应用初探

目的：初步探讨磁共振弥散张量成像（DTI）在颅脑高级别胶质瘤中的应用价值。方法：收集经手术病理证实高级别胶质瘤13例,均作了常规MRI平扫、增强扫描以及DTI,经计算机后处理获得平均弥散系数图（MD图）及部分各向异性指数图（FA图）,测定肿瘤实质区、囊变坏死区、瘤周水肿区及正常白质区的MD值、FA值,分析比较上述4个区MD值、FA值有无统计学差异。结果：肿瘤实质区、囊变坏死区、瘤周水肿区及正常白质区的MD值分别为0.976±0.171×10^-9mm^2/s、1.92±0.515×10^-9mm^2/s、1.414±0.288×10^-9mm^2/s、0.723±0.0525×10^-9mm^2/s,上述4个区域两两比较均有显著统计学差异（P〈0.01）;肿瘤实质区、囊变坏死区、瘤周水肿区及正常白质区的FA值分别为0.137±0.056、0.0824±0.061、0.148±0.09、0.522±0.073,囊变坏死区、肿瘤实质区、瘤周水肿区与正常白质区比较均有显著统计学差异（P〈0.001）,而囊变坏死区、肿瘤实质区及瘤周水肿区之间均无统计学差异（P〉0.05）。结论：DTIMD值可区分高级别胶质瘤肿瘤实质区、囊变坏死区、瘤周水肿区及正常白质区;FA值可区分肿瘤区与正常白质区,但不易区分肿瘤实质区、囊变坏死区与瘤周水肿区。

Application study of diffusion tensor MR imaging on high grade cerebral gliomas

Objective To investigate the application value of diffusion tensor MR imaging on the high grade cerebral gliomas. Methods Thirteen patients proved by surgical pathology underwent MRI plain and contrastenhanced scanning and diffusion tensor MR imaging. Mean diffusivity （MD） and fractional anisotropy （FA） values were measured in regions of solid tumor, surrounding edema, cystic or necrotic and normal white matter. Differences in these values among the tissues were assessed. Results Apparently significant differences of MD were found in solid tumor （0. 976 ±0. 171 × 10^-9 mm^2/s）, cystic or necrotic （ 1.92±0. 515 × 10-^9 mm^2/s）, surrounding edema （ 1.414 ±0.288 ×10-^9 mm^2/s）, compared with normal white matter regions （0.723±0.0525 × 10-^9mm^2/s） （P 〈0. 01 ）. There were greatly obviously significant differences of FA between solid tumor （0. 137 ±0.056）, cystic or necrotic （0.0824±0.061）, surrounding edema （0. 148±0.09） and normal white matter region （0.522±0.073） （P〈0.001）. But there was no significant difference among solid tumor, cystic or necrotic and surrounding edema region （P〉0.05）.Condusion MD can be used to differentiate normal white matter, solid tumor, cystic or necrotic region, and surrounding edema region. FA may not be effective in tissue differentiation, but can be used to differentiate tumor tissues from normal white matter region.