Neuroimaging of Infectious Vasculopathy

The outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China, is serious and has the potential to become an epidemic worldwide. Several studies have described typical clinical manifestations including fever, cough, diarrhea, and fatigue. However, to our knowledge, it has not been reported that patients with COVID-19 had any neurologic manifestations.

Inflammation plays an important role in the pathogenesis of ischemic stroke and other forms of ischemic brain injury. Experimentally and clinically, the brain responds to ischemic injury with an acute and prolonged inflammatory process, characterized by rapid activation of resident cells (mainly microglia), production of proinflammatory mediators, and infiltration of various types of inflammatory cells (including neutrophils, different subtypes of T cells, monocyte/macrophages, and other cells) into the ischemic brain tissue. These cellular events collaboratively contribute to ischemic brain injury. Despite intense investigation, there are still numerous controversies concerning the time course of the recruitment of inflammatory cells in the brain and their pathogenic roles in ischemic brain injury. In this review, we provide an overview of the time-dependent recruitment of different inflammatory cells following focal cerebral I/R. We discuss how these cells contribute to ischemic brain injury and highlight certain recent findings and currently unanswered questions about inflammatory cells in the pathophysiology of ischemic stroke.

Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging with CTA, MRA, or DSA. The technique has multiple potential uses in the context of ischemic stroke and intracranial hemorrhage. There remain gaps in our understanding of intracranial vessel wall MR imaging findings and research is ongoing, but the technique is already used on a clinical basis at many centers. This article, on behalf of the Vessel Wall Imaging Study Group of the American Society of Neuroradiology, provides expert consensus recommendations for current clinical practice.