“…You will refresh and renew your knowledge about juvenile idiopathic arthritis both from radiological [1] and clinical perspectives [2], but also find different insights into very common topics, such as gastro-esophageal reflux and constipation [3]. Important diagnostic hints in imaging of unusual (viral, bacterial, and parasitic) lung infections and their clinical and imaging mimics is presented [4]. As a leading cause of infectious morbidity and mortality in immunocompromised children, a comprehensive review of pulmonary infections in these children is included in this special issue, along with their differential diagnoses [5].…”