Mascalchi Mario, Pantoni Leonardo, Giannelli Marco, Valenti Raffaella, Bianchi Andrea, Pracucci Giovanni, Orsolini Stefano, Ciulli Stefano, Tessa Carlo, Poggesi Anna, Pescini Francesca, Inzitari Domenico, Diciotti Stefano
Neuroradiology Unit A. Meyer Children Hospital of Florence, Italy.
Department of Clinical and Experimental Biomedical Sciences, University of Florence, Italy.
J Neuroimaging. 2017 Jan;27(1):85-91. doi: 10.1111/jon.12374. Epub 2016 Jun 30.
Diffusion tensor imaging (DTI) is sensitive to brain microstructural changes. The aims of this DTI study were to map voxelwise the spatial distribution of brain microstructural changes in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and to investigate any correlation between DTI-derived indices and extension of T2 hyperintensity.
Eighteen patients with CADASIL and 18 age-, sex-, and education-level-matched healthy controls underwent magnetic resonance imaging at 3 T. Differences in DTI-derived indices (mean diffusivity [MD], fractional anisotropy [FA], axial [AD] and radial [RD] diffusivities, and mode of anisotropy [MO]) of brain white matter (WM) between CADASIL patients and healthy subjects were assessed through tract-based spatial statistics. Then, DTI-derived indices were correlated with the patient's score on the extended Fazekas visual scale of the T2 hyperintensity.
When compared to healthy controls, CADASIL patients showed extensive symmetric areas of increased MD/RD and decreased AD/FA/MO that involved almost the entire hemispheric cerebral WM (internal and external capsule, WM of the temporal poles, superior and inferior longitudinal fasciculus, inferior frontal-occipital fasciculus, uncinate fasciculus, cingulum, forceps major and minor, corticospinal tracts, and thalamic radiations), thalami, and corpus callosum. Additional areas of increased RD were observed in pons, midbrain, cerebellar peduncles, and cerebellar WM. Only FA was negatively correlated with extended Fazekas visual score.
Our results indicate that brain damage in CADASIL is associated with extensive microstructural changes implying impairment of intra- and inter-hemispheric cerebral, thalamocortical, and cerebrocerebellar connections. Severity of microstructural changes correlates with extension of T2 hyperintensity.
扩散张量成像（DTI）对脑微观结构变化敏感。本DTI研究的目的是体素水平绘制常染色体显性遗传性脑动脉病伴皮质下梗死和白质脑病（CADASIL）患者脑微观结构变化的空间分布，并研究DTI衍生指标与T2高信号范围之间的相关性。
18例CADASIL患者和18例年龄、性别、教育水平匹配的健康对照者接受3T磁共振成像。通过基于纤维束的空间统计学评估CADASIL患者与健康受试者脑白质（WM）的DTI衍生指标（平均扩散率[MD]、各向异性分数[FA]、轴向[AD]和径向[RD]扩散率以及各向异性模式[MO]）的差异。然后，将DTI衍生指标与患者T2高信号扩展的Fazekas视觉量表评分相关联。
与健康对照相比，CADASIL患者显示出广泛对称区域的MD/RD增加和AD/FA/MO降低，几乎累及整个半球脑白质（内囊和外囊、颞极白质、上纵束和下纵束、额枕下束、钩束、扣带、胼胝体主要和次要钳、皮质脊髓束和丘脑辐射）、丘脑和胼胝体。在脑桥、中脑、小脑脚和小脑白质中观察到RD增加的其他区域。只有FA与扩展的Fazekas视觉评分呈负相关。
我们的结果表明，CADASIL中的脑损伤与广泛的微观结构变化相关，这意味着半球内和半球间脑、丘脑皮质和脑小脑连接受损。微观结构变化的严重程度与T2高信号范围相关。
