The importance of heart and brain imaging in children and adolescents with Multisystem Inflammatory Syndrome in Children (MIS-C)

Multisystem Inflammatory Syndrome in Children (MIS-C) recently reported in a minority of children affected by SARS-CoV-2, mimics Kawasaki disease (KD), a medium vessel vasculitis of unknown cause. In contrast to acute COVID-19 infection, which is usually mild in children, 68% of patients with MIS-C will need intensive care unit. Myocarditis and coronary artery ectasia/aneurysm are included between the main cardiovascular complications in MIS-C. Therefore, close clinical assessment is need it both at diagnosis and during follow-up. Echocardiography is the cornerstone modality for myocardial function and coronary artery evaluation in the acute phase. Cardiovascular magnetic resonance (CMR) detects diffuse myocardial inflammation including oedema/fibrosis, myocardial perfusion and coronary arteries anatomy during the convalescence and in adolescents, where echocardiography may provide inadequate images. Brain involvement in MIS-C is less frequent compared to cardiovascular disease. However, it is not unusual and should be monitored by clinical evaluation and brain magnetic resonance (MRI), as we still do not know its effect in brain development. Brain MRI in MIS-C shows T2-hyperintense lesions associated with restricted diffusion and bilateral thalamic lesions. To conclude, MIS-C is a multisystem disease affecting many vital organs, such as heart and brain. Clinical awareness, application of innovative, high technology imaging modalities and advanced treatment protocols including supportive and anti-inflammatory medication will help physicians to prevent the dreadful complications of MIS-C.