While the degree of cerebellar tonsillar descent is considered the primary radiologic marker of Chiari malformation type I (CMI), biomechanical forces acting on the brain tissue in CMI subjects are less studied and poorly understood. In this study, regional brain tissue displacement and principal strains in 43 CMI subjects and 25 controls were quantified using a magnetic resonance imaging (MRI) methodology known as displacement encoding with stimulated echoes (DENSE). Measurements from MRI were obtained for seven different brain regions—the brainstem, cerebellum, cingulate gyrus, corpus callosum, frontal lobe, occipital lobe, and parietal lobe. Mean displacements in the cerebellum and brainstem were found to be 106 and 64% higher, respectively, for CMI subjects than controls (p < .001). Mean compression and extension strains in the cerebellum were 52 and 50% higher, respectively, in CMI subjects (p < .001). Brainstem mean extension strain was 41% higher in CMI subjects (p < .001), but no significant difference in compression strain was observed. The other brain structures revealed no significant differences between CMI and controls. These findings demonstrate that brain tissue displacement and strain in the cerebellum and brainstem might represent two new biomarkers to distinguish between CMI subjects and controls.

虽然小脑扁桃体下降程度被认为是 I 型 Chiari 畸形 (CMI) 的主要放射学标志，但作用于 CMI 受试者脑组织的生物力学力的研究较少且了解甚少。在这项研究中，使用称为受激回波位移编码( DENSE ) 的磁共振成像 (MRI) 方法对 43 名 CMI 受试者和 25 名对照者的区域脑组织位移和主应变进行了量化。通过 MRI 测量了七个不同的大脑区域——脑干、小脑、扣带回、胼胝体、额叶、枕叶和顶叶。研究发现，CMI 受试者的小脑和脑干平均位移分别比对照组高 106% 和 64% ( p < .001)。 CMI 受试者的小脑平均压缩应变和伸展应变分别高出 52% 和 50% ( p < .001)。 CMI 受试者的脑干平均伸展应变高出 41% ( p < .001)，但压缩应变没有观察到显着差异。其他大脑结构显示 CMI 和对照组之间没有显着差异。这些发现表明，小脑和脑干中的脑组织位移和应变可能代表了区分 CMI 受试者和对照组的两种新生物标志物。