类淋巴系统主动交换脑脊液（CSF）和间质液（ISF），以消除脑实质中有毒的间质废物溶质。类淋巴系统损伤与多种神经系统疾病有关。胶质母细胞瘤，也称为多形性胶质母细胞瘤 (GBM) 是胶质瘤类别中一种高度侵袭性的恶性脑癌。然而，GBM 对类淋巴系统功能的影响尚未得到研究。使用动态对比增强磁共振成像 (CE-MRI) 和先进的动力学模型，我们检查了 GBM 大鼠的类淋巴系统的变化。动态 3D 对比增强 T1 加权成像 (T1WI) 与小脑延髓池内 (ICM) ）输注顺磁性 Gd-DTPA 造影剂用于 GBM 诱导大鼠和对照大鼠的 MRI 类淋巴测量。使用模型导出的到达时间、输注速率、清除率和残差等参数来分析整个大脑和嗅球中的类淋巴液流量，这些参数描述了脑脊液示踪剂随时间的动态变化。3D 动态 T1WI 数据识别出类淋巴液流入和清除减少，表明 GBM 导致类淋巴系统受损。动力学模型和定量分析一致表明，与对照大鼠相比，GBM 大鼠的输注速率、清除率显着降低，脑脊液示踪剂残留增加，表明 GBM 大脑中的类淋巴液流受到限制。此外，我们的结果还发现 GBM 大鼠视神经周围神经通路受损。我们的研究表明，大鼠大脑中存在 GBM 受损的类淋巴反应，并且沿视神经的神经周围通路受损。类淋巴废物清除减少可能导致有毒废物溶质和促炎信号分子的积累，这可能会影响 GBM 的进展。© 2023。作者。

The glymphatic system actively exchanges cerebrospinal fluid (CSF) and interstitial fluid (ISF) to eliminate toxic interstitial waste solutes from the brain parenchyma. Impairment of the glymphatic system has been linked to several neurological conditions. Glioblastoma, also known as Glioblastoma multiforme (GBM) is a highly aggressive form of malignant brain cancer within the glioma category. However, the impact of GBM on the functioning of the glymphatic system has not been investigated. Using dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) and advanced kinetic modeling, we examined the changes in the glymphatic system in rats with GBM.Dynamic 3D contrast-enhanced T1-weighted imaging (T1WI) with intra-cisterna magna (ICM) infusion of paramagnetic Gd-DTPA contrast agent was used for MRI glymphatic measurements in both GBM-induced and control rats. Glymphatic flow in the whole brain and the olfactory bulb was analyzed using model-derived parameters of arrival time, infusion rate, clearance rate, and residual that describe the dynamics of CSF tracer over time.3D dynamic T1WI data identified reduced glymphatic influx and clearance, indicating an impaired glymphatic system due to GBM. Kinetic modeling and quantitative analyses consistently indicated significantly reduced infusion rate, clearance rate, and increased residual of CSF tracer in GBM rats compared to control rats, suggesting restricted glymphatic flow in the brain with GBM. In addition, our results identified compromised perineural pathway along the optic nerves in GBM rats.Our study demonstrates the presence of GBM-impaired glymphatic response in the rat brain and impaired perineural pathway along the optic nerves. Reduced glymphatic waste clearance may lead to the accumulation of toxic waste solutes and pro-inflammatory signaling molecules which may affect the progression of the GBM.© 2023. The Author(s).