TOPLINE:

An international consortium developed and validated a standardised framework for assessing brain MRI patterns in patients with COVID-19 and neurologic symptoms, successfully capturing 94% of imaging abnormalities.

METHODOLOGY:

• Researchers conducted an international, multicentre, retrospective observational study including 458 patients with COVID-19 (mean age, 62.1 years; 67.5% men) from 25 centres across France, Italy, Spain, the United Kingdom, and Brazil between February and May 2020.
• Brain MRI scans were performed on 1.5T or 3.0T systems, with a mean delay of 22.8 days after the onset of symptoms (mainly respiratory symptoms). Protocols included T2-weighted imaging, fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging, and haemorrhage-sensitive sequences.
• Two readers at each centre independently classified imaging findings using a predefined framework covering stroke (ischaemic and haemorrhagic) and non-stroke (white and grey matter and leptomeningeal) patterns.
• Patient outcomes were death or discharge to home.

TAKEAWAY:

• About 58.5% of MRI scans were abnormal, and the proposed framework successfully captured 252 of 268 (94%) MRI abnormalities. However, patient outcomes did not differ substantially across MRI patterns.
• Ischaemic infarcts were the most prevalent overall (25.6%), occurring more frequently in patients not in the ICU than in those in the ICU (34.9% vs 18.6%).
• Haemorrhagic lesions were more common in patients in the ICU than in those not in the ICU (32.3% vs 9.2%), with cerebral microbleeds being the most predominant pattern (15.9%).
• White matter lesions were more frequent than grey matter lesions (10.9% vs 8.1%), and leptomeningeal contrast enhancement was present in 8.3% of all patients and 25.3% of those receiving post-gadolinium FLAIR imaging.

IN PRACTICE:

"Our proposed structured framework proved highly pertinent to capturing the various neuropathological disease processes associated with COVID-19 and could in the future facilitate a standardized reporting of brain MRI findings in acute COVID-19," the authors wrote.

SOURCE:

This study was led by Stéphane Kremer, Hôpitaux Universitaires de Strasbourg, Strasbourg, France. It was published online on September 26, 2025, in Neuroradiology.

LIMITATIONS:

The retrospective design introduced several limitations, including potential selection bias due to over half of the patients being in the ICU during the first pandemic wave, when MRI was restricted to clinically essential cases. This may have led to an underrepresentation of patients with relatively mild neurologic symptoms. Additionally, a delay was observed between the onset of COVID-19 symptoms and MRI scans, and the multicentre design prevented the standardisation of MRI protocols. The lack of systematic contrast-enhanced FLAIR imaging likely resulted in an underestimation of the incidence of leptomeningeal contrast enhancement.

DISCLOSURES:

This study did not receive any external funding. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.