Structured assessment of brain MRI in Covid-19-related neurological disease: an international multicentre study.

Purpose: Neuroradiological findings associated with neurological presentations in acute SARS-CoV-2 infection are very heterogeneous. We aimed to develop a standardized framework for describing MR neuroimaging patterns in Covid-19, to test this in an international multicentre study and to determine the prevalence of observed MRI patterns and their association with clinical presentation and outcome.

Methods: An international expert consortium developed a framework for assessment of brain MRI patterns in Covid-19 based on published literature and professional experience. We performed a retrospective analysis of the proposed framework, involving brain MRI scans from 458 Covid-19 patients with neurological symptoms, including data from 1 February to 31 May 2020. Two readers at 25 centres across five countries assessed the local MRI studies regarding the presence of one or more predefined MRI patterns. Imaging and clinical data were analysed using Bayesian statistics.

Results: Of 458 patients, 58.5% had an abnormal MRI. Overall, 94% of all imaging pathologies seen were captured by our proposed classification. Ischemic strokes were the most frequent pattern overall (25.6%), followed by microhaemorrhages (15.9%). Ischemic infarct patterns were more frequent in non-ICU patients, while the haemorrhagic patterns were more frequent in ICU patients. White matter lesions (10.9%) were more frequent than grey matter lesions (8.1%), and leptomeningeal contrast enhancement was present in 8.3% of patients. Patient outcome was not associated with any MRI patterns.

Conclusion: Our proposed classification of specific MRI patterns in Covid-19, covered 94% of observed abnormalities, while patient outcome, death or home discharge, was not associated with any MRI patterns.