Fan Di, Chaudhari Nikhil N, Rostowsky Kenneth A, Calvillo Maria, Lee Sean K, Chowdhury Nahian F, Zhang Fan, O'Donnell Lauren J, Irimia Andrei
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:198-203. doi: 10.1109/EMBC.2019.8857921.
Cerebral microbleeds (CMBs), a common manifestation of mild traumatic brain injury (mTBI), have been sporadically implicated in the neurocognitive deficits of mTBI victims but their clinical significance has not been established adequately. Here we investigate the longitudinal effects of post-mTBI CMBs upon the fractional anisotropy (FA) of white matter (WM) in 21 older mTBI patients across the first ~6 months post-injury. CMBs were segmented automatically from susceptibility-weighted imaging (SWI) by leveraging the intensity gradient properties of SWI to identify CMB-related hypointensities using gradient-based edge detection. A detailed diffusion magnetic resonance imaging (dMRI) atlas of WM was used to segment and cluster tractography streamlines whose prototypes were then identified. The correlation coefficient was calculated between (A) FA values at vertices along streamline prototypes and (B) topological (along-streamline) distances between these vertices and the nearest CMB. Across subjects, the CMB identification approach achieved a sensitivity of 97.1% ± 4.7% and a precision of 72.4% ± 11.0% across subjects. The correlation coefficient was found to be negative and, additionally, statistically significant for 12.3% ± 3.5% of WM clusters (p <; 0.05, corrected), whose FA was found to decrease, on average, by 11.8% ± 5.3% across the first 6 months post-injury. These results suggest that CMBs can be associated with deleterious effects upon peri-lesional WM and highlight the vulnerability of older mTBI patients to neurovascular injury.
脑微出血（CMBs）是轻度创伤性脑损伤（mTBI）的常见表现，偶尔被认为与mTBI患者的神经认知缺陷有关，但其临床意义尚未得到充分证实。在此，我们研究了21例老年mTBI患者在伤后约6个月内，mTBI后CMBs对白质（WM）各向异性分数（FA）的纵向影响。利用磁敏感加权成像（SWI）的强度梯度特性，通过基于梯度的边缘检测识别与CMB相关的低信号，从而从SWI中自动分割出CMBs。使用详细的WM扩散磁共振成像（dMRI）图谱对纤维束成像流线进行分割和聚类，然后确定其原型。计算（A）沿流线原型各顶点的FA值与（B）这些顶点与最近CMB之间的拓扑（沿流线）距离之间的相关系数。在所有受试者中，CMB识别方法的敏感性为97.1%±4.7%，精确度为72.4%±11.0%。发现相关系数为负，此外，在12.3%±3.5%的WM簇中具有统计学意义（p<0.05，校正），其FA在伤后前6个月平均下降11.8%±5.3%。这些结果表明，CMBs可能与病灶周围WM的有害影响有关，并突出了老年mTBI患者对神经血管损伤的易感性。
