Publication timeline of chest imaging reporting in children with coronavirus disease 2019 (COVID-19): a systematic review spanning 2020.

Amid the coronavirus disease 2019 (COVID-19) pandemic, numerous publications of imaging findings in children have surfaced in a very short time. Publications discuss populations of overlapping age groups and describe different imaging patterns. We aim to present an overview of the quantity and type of literature available regarding COVID-19 chest imaging findings in children according to a 2020 publication timeline. We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. We searched terminology related to COVID-19, chest, children and imaging modalities in PubMed and Embase. The included papers were published online in 2020 and described imaging findings specific to children and reported five or more cases. Two researchers reviewed each abstract to determine inclusion or exclusion, and a radiologist reconciled any disagreements. Then we reviewed full articles for the main analysis. Eligible study designs included original articles, case series (≥5 cases), systematic reviews and meta-analyses. We excluded non-English manuscripts, retracted articles, and those without available full text. The remaining articles were distributed to four pediatric radiologists (on the Society for Pediatric Radiology Thoracic Committee), who summarized chest imaging findings. Eighty-two articles were included in the final analysis - 28% in radiology journals and 71% in non-radiology journals; 71% contained original data and 29% were review-style papers. There was a disproportionate contribution of review-style papers in April (55%), considering the paucity of preceding publications with original data in March (5 papers). June had the highest number of publications (n=14), followed by April (n=11) and July (n=11). Most (52%) original papers were from China and most individual pediatric imaging descriptions were from China (57%), while the majority of review papers (83%) were international. Imaging descriptions were available for 2,199 children (1,678 CT descriptions and 780 chest radiography descriptions). Findings included a 25% normal CT scan reports vs. 40% normal chest radiography reports. Ground-glass opacification was the most common CT finding (33%) and was reported in only a minority of chest radiographs (9%). A significant amount of information on pediatric COVID-19 chest imaging has become rapidly available over a short period. Most publications in 2020 were original articles, but they were published more often in non-radiology journals. A disproportionate number of review articles were published early on and were based on little original pediatric imaging data. CT scan reports, which represent the standard, outnumbered radiographic reports and indicated that ground-glass opacification is the main imaging finding and that only a quarter of scans are normal in children with COVID-19.