Institute for Stroke and Dementia Research, University Hospital, LMU Munich, Munich, Germany.
Institute for Stroke and Dementia Research, University Hospital, LMU Munich, Munich, Germany.
Alzheimers Dement. 2018 Jun;14(6):764-774. doi: 10.1016/j.jalz.2017.12.007. Epub 2018 Feb 16.
Diffusion tensor imaging detects early tissue alterations in Alzheimer's disease and cerebral small vessel disease (SVD). However, the origin of diffusion alterations in SVD is largely unknown.
To gain further insight, we applied free water (FW) imaging to patients with genetically defined SVD (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy [CADASIL], n = 57), sporadic SVD (n = 444), and healthy controls (n = 28). We modeled freely diffusing water in the extracellular space (FW) and measures reflecting fiber structure (tissue compartment). We tested associations between these measures and clinical status (processing speed and disability).
Diffusion alterations in SVD were mostly driven by increased FW and less by tissue compartment alterations. Among imaging markers, FW showed the strongest association with clinical status (R up to 34%, P < .0001). Findings were consistent across patients with CADASIL and sporadic SVD.
Diffusion alterations and clinical status in SVD are largely determined by extracellular fluid increase rather than alterations of white matter fiber organization.
扩散张量成像可检测阿尔茨海默病和脑小血管病（SVD）的早期组织改变。然而，SVD 中扩散改变的起源在很大程度上尚不清楚。
为了更深入地了解这一问题，我们应用游离水（FW）成像技术对遗传性 SVD（伴有皮质下梗死和白质脑病的常染色体显性脑动脉病[CADASIL]，n=57）、散发性 SVD（n=444）和健康对照组（n=28）的患者进行了研究。我们对细胞外空间（FW）中自由扩散的水和反映纤维结构（组织区室）的测量值进行建模。我们测试了这些指标与临床状况（处理速度和残疾）之间的相关性。
SVD 中的扩散改变主要是由 FW 的增加引起的，而由组织区室改变引起的则较少。在影像学标志物中，FW 与临床状况的相关性最强（R 高达 34%，P<.0001）。这些发现与 CADASIL 和散发性 SVD 患者的情况一致。
SVD 中的扩散改变和临床状况主要是由细胞外液增加引起的，而不是白质纤维组织排列改变引起的。
