Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China.
Department of Neurosurgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China.
Magn Reson Imaging. 2019 Oct;62:1-9. doi: 10.1016/j.mri.2019.01.017. Epub 2019 Jan 17.
The blood-brain barrier (BBB) and cerebral tissue microstructure can be impaired following traumatic brain injury (TBI). However, the spatiotemporal changes of BBB leakage and tissue microstructure are not completely understood. In this study, we evaluated the spatiotemporal changes of BBB leakage and tissue microstructure using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion kurtosis imaging (DKI) in controlled cortical impact (CCI) rats.
The DCE-MRI parameters volume transfer coefficient (K) and DKI parameters were longitudinally measured in bilateral cortex, hippocampus, thalamus and corpus callosum (CC) at baseline (D0), acute stage (D1, D3), and subacute stage (D7, D14 and D28) post-injury. Immunohistochemistry analysis was performed at D28 after MRI scanning. Repeated-measures ANOVA was used to assess the temporal changes of MRI parameters.
K abnormality was only localized to ipsilateral perilesional cortex with a significant temporal change (F = 144.2, p < 0.0001). Compared to baseline, increased mean kurtosis (MK) was observed in ipsilateral regions of cortex and hippocampus and CC for all the time points (p < 0.05 for all). Increased MK was also observed in ipsilateral thalamus (p = 0.005) at subacute stage but not at acute stage while no change was observed with MD and FA (p > 0.05 for both). In ipsilateral cortex, the overall K value of D0, D1, D3, D7, D14, and D28 post-injury were significantly correlated with MK value (r = 0.84, p < 0.0001). The CCI group showed higher staining of glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba-1) and lower staining of neuron-specific nuclear protein (NeuN) and myelin basic protein (MBP) in ipsilateral regions of cortex, hippocampus, thalamus and CC (p < 0.05 for all) as compared to control group. There were no significant differences in the contralateral regions by immunohistochemistry.
The BBB disruption reflected by K correlated well with MK value in ipsilateral cortex. In addition, MK could detect the delayed microstructural changes in thalamus. DCE-MRI and DKI could be used to assess the BBB breakdown and cerebral microstructural changes of TBI.
创伤性脑损伤（TBI）可导致血脑屏障（BBB）和脑组织微观结构受损。然而，BBB 渗漏和组织微观结构的时空变化尚不完全清楚。本研究采用动态对比增强磁共振成像（DCE-MRI）和扩散峰度成像（DKI）评估控制皮质撞击（CCI）大鼠 BBB 渗漏和组织微观结构的时空变化。
在损伤后基础状态（D0）、急性期（D1、D3）和亚急性期（D7、D14 和 D28），对双侧皮质、海马体、丘脑和胼胝体（CC）进行 DCE-MRI 测量，以获得体积转移系数（K）和 DKI 参数。在 MRI 扫描后第 28 天进行免疫组化分析。采用重复测量方差分析评估 MRI 参数的时间变化。
K 异常仅局限于对侧损伤区周围皮质，且具有显著的时间变化（F=144.2，p<0.0001）。与基础状态相比，所有时间点同侧皮质和海马体以及 CC 的平均峰度（MK）均增加（所有 p<0.05）。同侧丘脑的 MK 也在亚急性期增加（p=0.005），但在急性期没有增加，而 MD 和 FA 没有变化（均 p>0.05）。在同侧皮质，损伤后 D0、D1、D3、D7、D14 和 D28 的总 K 值与 MK 值呈显著相关（r=0.84，p<0.0001）。CCI 组同侧皮质、海马体、丘脑和 CC 区域的胶质纤维酸性蛋白（GFAP）和钙结合接头蛋白 1（Iba-1）染色增加，神经元特异性核蛋白（NeuN）和髓鞘碱性蛋白（MBP）染色减少（所有 p<0.05），而对照组则无差异。免疫组化分析在对侧区域无显著差异。
K 反映的 BBB 破坏与同侧皮质的 MK 值密切相关。此外，MK 可检测到丘脑的延迟性微观结构变化。DCE-MRI 和 DKI 可用于评估 TBI 的 BBB 破裂和脑微观结构变化。
