E1196. The Many Faces of COVID-19 in Neuroradiology: An Educational Case Series
University of Michigan Medical School
Division of Neuroradiology, Department of Radiology, University of Michigan
Patients with COVID-19 infection may present with a variety of extra-pulmonary complications, including those that involve the central nervous system. Herein, we introduce a variety of imaging patterns of brain lesions in patients with COVID-19 to discuss a subset of these manifestations on head CT and brain MRI, their respective risk factors, and clinical correlates to support their diagnosis.
Educational Goals / Teaching Points
The goals of this exhibit are to (1) discuss imaging modalities and findings of COVID-19-related brain lesions and the mimics; (2) review how past medical history and medications may alter risk of COVID-19-related brain lesions; highlight biomarkers that may aid in detection of COVID-19 related ischemia; review the way in which chest imaging correlates with COVID-19-related brain lesions; and (5) discuss the underlying pathophysiology of COVID-19-related brain lesions (ischemia, cytokine storm, coagulopathy, and treatment-related changes).
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The key points of this exhibit are as follows. Non-confluent multifocal white matter lesions with variable enhancement and hemorrhagic lesions are one of the common patterns of ischemic changes in patients with severe COVID-19 infection. Aberrant increases in D-dimer and ferritin levels may serve as indicators of acute stroke risk in patients with severe COVID-19 infection. Patients with risk factors for ischemic stroke and concurrent COVID-19 infection may be at an increased risk for thrombi involving large or medium sized arteries with large arterial territory infarctions due to a COVID-19-associated hypercoagulable state. Hemorrhagic cortical lesions may be found on imaging in patients with COVID-19, which can manifest as hemorrhagic cerebritis, encephalitis, or hemorrhagic PRES. This is likely related to COVID-19-associated coagulopathy and vasculopathy. Extensive or isolated microhemorrhages are commonly seen in patients with COVID-19 infection. Extensive white matter microhemorrhages located adjacent to and within the corpus callosum, however, are likely associated with shower emboli after ECMO. CT-based lung disease severity is predictive of acute intracranial abnormalities. Specifically, impaired autoregulation due to diffuse alveolar damage leads to linear dependence of cerebral blood flow on mean arterial blood pressure. Continuous heparin infusion for the treatment of COVID-19 associated coagulopathy may cause devastating intracranial hemorrhage due to underlying ischemic changes and endothelial damage.
Patients with COVID-19 may suffer a variety of CNS insults which may vary from hemorrhagic or non-hemorrhagic white matter or cortical lesions, large arterial territory infarctions, and micro- and macro-hemorrhages. Baseline risk factors for stroke and anticoagulation status may increase the risk for these complications, and chest CT findings as well as biomarkers can support diagnosis.