Pediatric Radiology | 2021
Imaging in support of the clinical diagnoses of COVID-19 and multisystem inflammatory syndrome in children
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed the way we practice pediatric radiology. Not only are we practicing in entirely newways with increased physical separation from both our colleagues and our patients, but we need to be attuned to the imaging findings of an entirely new disease and its complications. The impact of COVID-19 on the pediatric population is not as severe as it is in at-risk adult populations [1, 2]. However, infection occurs in children and can have a variety of manifestations including the multisystem inflammatory syndrome in children (MIS-C) [3]. In this issue of Pediatric Radiology, Dr. Fenlon and colleagues [4] from Columbia University report their experience with 47 children and young adults with clinically diagnosed COVID-19-associated MIS-C. They described a spectrum of imaging findings, many of which are subjective, across a variety of imaging modalities, with the general picture being one of leaky vasculature and third-spacing of fluid. These findings included peribronchial thickening, pleural effusions in younger (<10 years of age) children, small-volume ascites, and gallbladder and bowel wall thickening. While some children had the characteristic multifocal pulmonary opacities seen in adults with COVID-19, no imaging appearance was characteristic or diagnostic for MIS-C. In the February issue of Pediatric Radiology, Dr. Rostad and colleagues [5] from Emory University described their experience with 37 children with either COVID-19 or COVID-19 and symptoms meeting the Centers for Disease Control case definition for MIS-C. Their results differed somewhat from those of Fenlon et al. [4] on the specific pulmonary manifestations of MIS-C and the frequency of those manifestations. For example, Rostad et al. reported pleural effusions to be much more ubiquitous. However, Rostad et al.’s results again suggest a general picture of thirdspacing of fluid including pleural effusions, basal predominant lung opacities and reactive changes in the abdomen. While both series described the imaging manifestations of MIS-C to be more severe than those described for COVID-19 alone, neither adjusted for disease acuity/severity or resuscitation status. As such, the distinction between the disease and complications of management of the disease is blurred. Are the findings reported specific manifestations ofMIS-C? Or are they sequelae of aggressive resuscitation? Or both? In prior reports emphasizing the pulmonary manifestations of MIS-C in children, Blumfield et al. [6] andWinant et al. [7] described the occurrence of pulmonary emboli, which have been more extensively described in adult cohorts. Those authors considered acute respiratory distress syndrome (ARDS) to be a manifestation of MIS-C, which they postulated to be a post-viral syndrome related to autoimmunity and post-viral inflammation (“cytokine storm”). In total, it is unclear what the relation ofMIS-C is to aggravation of primary COVID-19 pneumonia, potentially complicated by pulmonary embolic disease from coagulopathy, and the effects of longstanding mechanical ventilation, fluid resuscitation and superimposed hospitalacquired infections on the lung parenchyma, all of whichmanifest as ARDS. In the early phases of the COVID-19 pandemic, when there was significant and growing uncertainty about the availability of diagnostic testing, there was some thought that imaging might play a role in diagnosis, particularly of characteristic lung disease. However, findings that are believed to be characteristic (i.e. highly prevalent in a population of confirmed cases) might not be all that specific for disease (i.e. predict the * Andrew T. Trout [email protected]