Richmond Sutton B, Rane Swati, Hanson Moriah R, Albayram Mehmet, Iliff Jeffrey J, Kernagis Dawn, Rosenberg Jens T, Seidler Rachael D
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA.
Department of Radiology, University of Washington School of Medicine, Seattle, Washington, USA.
Eur J Neurosci. 2023 May;57(10):1689-1704. doi: 10.1111/ejn.15974. Epub 2023 Apr 12.
The glymphatic system is a brain-wide network of perivascular pathways along which cerebrospinal fluid and interstitial fluid rapidly exchange, facilitating solute and waste clearance from the brain parenchyma. The characterization of this exchange process in humans has relied primarily upon serial magnetic resonance imaging following intrathecal gadolinium-based contrast agent injection. However, less invasive approaches are needed. Here, we administered a gadolinium-based contrast agent intravenously in eight healthy participants and acquired magnetic resonance imaging scans prior to and 30, 90, 180, and 360 min post contrast injection. Using a region-of-interest approach, we observed that peripheral tissues and blood vessels exhibited high enhancement at 30 min after contrast administration, likely reflecting vascular and peripheral interstitial distribution of the gadolinium-based contrast agent. Ventricular, grey matter and white matter enhancement peaked at 90 min, declining thereafter. Using k-means clustering, we identify distinct distribution volumes reflecting the leptomeningeal perivascular network, superficial grey matter and deep grey/white matter that exhibit a sequential enhancement pattern consistent with parenchymal contrast enhancement via the subarachnoid cerebrospinal fluid compartment. We also outline the importance of correcting for (otherwise automatic) autoscaling of signal intensities, which could potentially lead to misinterpretation of gadolinium-based contrast agent distribution kinetics. In summary, we visualize and quantify delayed tissue enhancement following intravenous administration of gadolinium-based contrast agent in healthy human participants.
类淋巴系统是一个遍布全脑的血管周围通路网络，脑脊液和组织间液沿此网络快速交换，促进溶质和废物从脑实质清除。在人类中，这种交换过程的特征主要依赖于鞘内注射钆基造影剂后的系列磁共振成像。然而，需要侵入性较小的方法。在此，我们对8名健康参与者静脉注射钆基造影剂，并在注射造影剂前以及注射后30、90、180和360分钟进行磁共振成像扫描。使用感兴趣区域方法，我们观察到外周组织和血管在造影剂给药后30分钟时显示出高增强，这可能反映了钆基造影剂的血管和外周组织间分布。脑室、灰质和白质的增强在90分钟时达到峰值，此后下降。使用k均值聚类，我们识别出不同的分布容积，反映软脑膜血管周围网络、浅层灰质和深层灰质/白质，其呈现出与通过蛛网膜下腔脑脊液隔室的实质造影剂增强一致的顺序增强模式。我们还概述了校正（否则为自动的）信号强度自动缩放的重要性，这可能会导致对钆基造影剂分布动力学的误解。总之，我们在健康人类参与者中可视化并量化了静脉注射钆基造影剂后延迟的组织增强。
