The case series, published in the journal Radiology, examined the spectrum of X-ray scan findings in children who were hospitalised from April 14 to May 9 with the post-COVID-19 inflammatory condition known as Multisystem Inflammatory Syndrome.
According to the researchers, including those from Evelina London Children's Hospital in the UK, the children displayed signs of airway inflammation and rapid development of edema in the lungs, localised swelling of the coronary artery, and extensive intra-abdominal inflammatory changes.
They said the hospital experienced a surge of children with a multi-system hyperinflammatory syndrome and a variety of symptoms, including fever, headaches, abdominal pain, rashes, and conjunctivitis.
These clinical features and lab findings shared some similarities to those of Kawasaki disease which causes inflammation in the walls of blood vessels, the study noted.
"Our hospital saw an unprecedented cluster of children presenting with MIS-C, a new hyperinflammatory syndrome in children related to the current COVID-19 pandemic -- the recognition of which led to a national alert," said the study's lead author Shema Hameed from the Evelina London Children's Hospital.
In the current study, the scientists performed a retrospective review of the clinical, laboratory, and imaging findings of the first 35 children under age 17 who were admitted to the pediatric hospital that met the case definition for MIS-C.
From their analysis, the researchers said the most common clinical presentation was fever, found in 33 (94 per cent) of the children, gastrointestinal symptoms including abdominal pain, vomiting and diarrhea in 30 (86 per cent) of the children, rash (13 or 37 per cent), and conjunctivitis (9 or 26 per cent).
According to the scientists, the clinical status was severe enough to warrant management in the pediatric intensive care unit in 24 of 35 children, of which seven required mechanical ventilation.
Two children required special oxygen support due to severe heart dysfunction, they said.
Based on lab tests, the study said all of the children had abnormal white blood cell counts.
In imaging findings of post COVID-19 MIS-C children, the scientists found airway inflammation, rapidly progressive pulmonary edema, coronary artery aneurysms, and extensive abdominal inflammatory changes.
They said all the 35 children underwent chest X-ray due to fever, sepsis, or features of multisystem inflammation.
Nineteen X-rays were abnormal, the scientists said, adding that the most common finding being was thickening of the large air passages which lead from the windpipe to the lungs.
"As pediatric radiologists, we were interested in the emerging pattern of imaging findings that we observed in these children. Our intention is to bring these findings to the attention of the wider radiological community," Hameed said.
The researchers believe that future studies should be conducted in a larger group of patients, utilising multi-center databases to assess the radiological findings alongside the complex clinical course of children. VIS VIS