Gray Matter Nucleus Hyperintensity After Monthly Triple-Dose Gadopentetate Dimeglumine With Long-term Magnetic Resonance Imaging.

OBJECTIVES: Gadolinium deposition is widely believed to occur, but questions regarding accumulation pattern and permanence remain. We conducted a retrospective study of intracranial signal changes on monthly triple-dose contrast-enhanced magnetic resonance imaging (MRI) examinations from the previously published Betaseron vs. Copaxone in Multiple Sclerosis With Triple-Dose Gadolinium and 3-Tesla MRI Endpoints Trial (N = 67) to characterize the dynamics of gadolinium deposition in several deep brain nuclei and track persistence versus washout of gadolinium deposition on long-term follow-up (LTFU) examinations (N = 28) obtained approximately 10 years after enrollment in the Betaseron vs. Copaxone in Multiple Sclerosis With Triple-Dose Gadolinium and 3-Tesla MRI Endpoints Trial. MATERIALS AND METHODS: Using T2 and proton density images and using image analysis software (ITK-SNAP), manual regions of interest were created ascribing boundaries of the caudate nucleus, dentate nucleus, globus pallidus, pulvinar, putamen, white matter, and air. Intensity analysis was conducted on T1-weighted fat-saturated (fat-sat) images using the FSL package. A linear rigid-body transform was calculated from the fat-sat image at each target time point to the region of interest segmentation reference time point fat-sat image. Serial MRI signal was analyzed using linear mixed regression modeling with random intercept. Annual MRI signal changes including LTFU scans were assessed with t test. RESULTS: During monthly scanning, all gray matter structures demonstrated a significant (P < 0.0001) increase in contrast-to-noise ratio. Yearly changes in deposition showed distinctive patterns for the specific nucleus: globus pallidus showed complete retention, pulvinar showed partial washout, while dentate, caudate, and putamen returned to baseline (ie, complete washout). CONCLUSIONS: Monthly increased contrast-to-noise ratio in gray matter nuclei is consistent with gadolinium deposition over time. The study also suggests that some deep gray matter nuclei permanently retain gadolinium, whereas others demonstrate washout of soluble gadolinium.

Stroke in COVID-19: a single-centre initial experience in a hotspot of the pandemic.

BACKGROUND: COVID-19, caused by SARS-CoV-2, is a global pandemic that has been an immense burden on healthcare systems all over the world. These patients may be at higher risk for acute ischaemic stroke (AIS). We present our experience with AIS in patients with COVID-19. METHODS: We reviewed all patients admitted to our hospital during a 6-week period with a positive nasopharyngeal swab test for SARS-CoV-2. Among these patients, we identified AIS. We reviewed the demographics, clinical, laboratory, imaging characteristics, treatments received and outcomes of AIS in patients with COVID-19. RESULTS: We identified 683 patients admitted with COVID-19 during the study period, of which 20 patients had AIS. Large-vessel occlusion (LVO) was noted in 11 patients (55%). Intravenous alteplase was administered in four patients (20%) and mechanical thrombectomy was performed in five patients (25%). Respiratory symptoms preceded the onset of AIS in most of the patients (70%) by 1 to 21 days. Mortality in patients with AIS was 50% compared with 26% of all COVID-19 admissions. Most of these patients died due to non-neurological causes (70%). Three patients with AIS had clinical and imaging findings consistent with COVID-19, but were negative for multiple nasopharyngeal swab tests. INTERPRETATION: LVO was more common in patients with AIS and COVID-19. They had more severe disease and higher mortality rates. Most of the patients had respiratory symptoms preceding AIS by days to weeks. This could explain certain patients with clinical picture of COVID-19 but negative nasopharyngeal swab tests.