Department of Anesthesiology, Yale School of Medicine, 330 Cedar St, TMP 3, New Haven, CT, 06520, USA.
Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
Sci Rep. 2020 Sep 3;10(1):14592. doi: 10.1038/s41598-020-71582-x.
Dynamic contrast-enhanced magnetic resonance imaging (MRI) for tracking glymphatic system transport with paramagnetic contrast such as gadoteric acid (Gd-DOTA) administration into cerebrospinal fluid (CSF) requires pre-contrast data for proper quantification. Here we introduce an alternative approach for glymphatic system quantification in the mouse brain via T1 mapping which also captures drainage of Gd-DOTA to the cervical lymph nodes. The Gd-DOTA injection into CSF was performed on the bench after which the mice underwent T1 mapping using a 3D spoiled gradient echo sequence on a 9.4 T MRI. In Ketamine/Xylazine (KX) anesthetized mice, glymphatic transport and drainage of Gd-DOTA to submandibular and deep cervical lymph nodes was demonstrated as 25-50% T1 reductions in comparison to control mice receiving CSF saline. To further validate the T1 mapping approach we also verified increased glymphatic transport of Gd-DOTA transport in mice anesthetized with KX in comparison with ISO. The novel T1 mapping method allows for quantification of glymphatic transport as well as drainage to the deep and superficial cervical lymph nodes. The ability to measure glymphatic transport and cervical lymph node drainage in the same animal longitudinally is advantageous and time efficient and the coupling between the two systems can be studied and translated to human studies.
动态对比增强磁共振成像（MRI）通过顺磁性对比剂（如钆喷替酸葡甲胺（Gd-DOTA））在脑脊液（CSF）中给药来追踪神经胶质淋巴系统的转运，需要进行对比前数据的采集以进行正确的定量分析。在这里，我们介绍了一种通过 T1 映射来定量研究小鼠脑内神经胶质淋巴系统的替代方法，该方法还可以捕获 Gd-DOTA 向颈淋巴结的引流。在 bench 上进行 CSF 中的 Gd-DOTA 注射后，使用 9.4 T MRI 上的 3D 扰相梯度回波序列对小鼠进行 T1 映射。在氯胺酮/甲苯噻嗪（KX）麻醉的小鼠中，与接受 CSF 盐水的对照小鼠相比，Gd-DOTA 的神经胶质转运和向颌下和深部颈淋巴结的引流导致 T1 降低了 25-50%。为了进一步验证 T1 映射方法，我们还验证了在 KX 麻醉的小鼠中，Gd-DOTA 转运的神经胶质转运增加，与 ISO 相比。该新的 T1 映射方法允许定量测量神经胶质转运以及向深部和浅部颈淋巴结的引流。能够在同一动物中进行纵向测量神经胶质转运和颈淋巴结引流的能力具有优势，并且省时高效，并且可以研究和转化这两个系统之间的耦合关系以用于人体研究。
