Research progress in the evaluation of glymphatic system function by the DTI-ALPS method / 中南大学学报(医学版)

The glymphatic system can remove metabolic wastes from the brain, which plays a significant role in maintaining the homeostasis of the central nervous system. It is an important basis for advanced cognitive functions such as learning and memory. Studies have analyzed the function of glymphatic system by diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) recently. Compared with other invasive examinations that require fluorescent tracer technique or the injection of contrast agents, DTI-ALPS can evaluate the hydromechanics of the glymphatic system via quantifying the diffusion rate of water molecules in different directions, which turns out to be a non-invasive in vivo neuroimaging method. The ALPS-index calculated by the DTI-ALPS method is significantly correlated with the cognitive function in diseases of central nervous system and other system and can reflect the dynamic changes of diseases. In general, ALPS-index is expected to become a novel neuroimaging biomarker for predicting prognosis and clinical effects.

Atypical Virchow-Robin SpacesMimicking Cystic Primary Brain Tumor ­ Clinical Report and Literature Review

The Virchow-Robin spaces (VRSs), which are often incidentally observed in modern structural neuroimaging examinations, are small cystic cavities that usually surround the small arteries and arterioles at the level of basal ganglia, the anterior perforated substance and the thalamic-mesencephalic junction. Typically, they have similar physicochemical characteristics to cerebral spinal fluid (CSF) and there is no contrast enhancement on brain CT andMRI images. Its real meaning is unknown, although some contemporary studies have suggested that it might be related to certain traumatic brain injury or several other central nervous system (CNS) disorders, as degenerative diseases. Occasionally, some wide and atypical VRS may be mistaken for primary cystic brain tumors, especially in the context of large and symptomatic lesions, multiple clustered cysts, cortical lesions and if there is adjacent reactive gliosis. The present paper reports four patients who were affected by atypical VRS mimicking brain tumors that required imaging follow-up or even a biopsy to confirm the diagnosis or to indicate the correct approach. Although it is not so unusual, one of them occurred concomitantly and adjacent to a diffuse glioma (co-deleted 1p19q, WHO-GII).