Imaging Findings in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID

Please see the Author Video associated with this article. Background: A multisystem inflammatory syndrome in children associated with COVID-19 (MIS-C) has recently been described. Objective: To evaluate imaging findings of MIS-C associated with COVID-19. Subjects and Methods: Imaging studies and medical records of sixteen patients (0-20 years) admitted with MIS-C were retrospectively reviewed. Thoracic imaging studies were evaluated for parenchymal, mediastinal and hilar, and cardiovascular abnormalities. Abdominal imaging studies were evaluated for abnormalities of solid viscera, hollow viscera, peritoneum, as well as the mesentery and retroperitoneum. Studies were reviewed independently by two radiologists, and disagreements were resolved by a third, senior radiologist. Results: Sixteen patients were included (10 male and 6 female; 20 months - 20 years). All 16 patients presented with fever. Other presenting signs and symptoms included: vomiting (12; 75%), abdominal pain (11; 69%), rash (10;62.5%), conjunctivitis (8;50%), diarrhea (7;44%), headache (6;37.5%), and sore throat (5;31%). Shortness of breath and cough were each present in one patient. Chest radiograph demonstrated cardiomegaly (10; 62.5%), congestive heart failure or pulmonary edema (9; 56%), atelectasis (9; 56%), pleural effusions (7; 44%), adult respiratory distress syndrome (2; 12.5%) and pneumonia (1; 6%). Absolute interobserver agreement was 69-100%. Eight patients (50%) were evaluated for PE (6 [75%] by CT angiography [CTA] and 2 [25%] by ventilation/perfusion scintigraphy). In 2 (25%), CTA demonstrated a segmental PE. Abdominal imaging findings (US and CT) included small volume ascites (6; 38%), hepatomegaly (6; 38%), echogenic kidneys (5; 31%), bowel wall thickening (3; 19%), gallbladder wall thickening (3; 19%), mesenteric lymphadenopathy (2; 13%), splenomegaly (1; 6%), and bladder wall thickening (1; 6%). The frequencies of findings based on all the reviewed modalities were: cardiomegaly (12; 75%), pleural effusion (10; 63%) and atelectasis (10; 63%). 15 patients (94%) were discharged home (length of hospital stay 3-20 days). There were no mortalities. Conclusion: MIS-C associated with COVID-19 is characterized predominantly by cardiovascular abnormalities, though also solid visceral organ, gallbladder, and bowel abnormalities as well as ascites, reflecting a multisystemic inflammatory process. Clinical Impact: The constellation of imaging findings in the setting of COVID-19 may alert pediatric radiologists to the diagnosis of MIS-C prior to rapid deterioration of patients.