1 | INTRODUCTION
Since the end of December 2019,
coronavirus disease (COVID-19) caused
by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has
rapidly spread worldwide, becoming the first pandemic of the
21st century1. Since the beginning
of the COVID-19 pandemic, children have been less frequently and
severely involved than adults, requiring hospitalization only in
5%–10% of cases2. This likely explains the paucity
of children-related articles in scientific literature, even with a
vertiginous increase in COVID-19 articles. However, recent studies have
identified an emerging novel spectrum of the disease in children,
including a multisystem inflammatory condition with overlapping features
of toxic shock syndrome 3. To date, the absolute
number of those cases with prominent cardiovascular compromise is still
low and respiratory symptoms remain the main reason for Pediatric
Intensive Care Unit admissions for COVID-19 4. The
PCR-rapid test is not feasible in all hospitals and a slow turnaround
time is an extra burden5. Therefore, a rapid,
economical and reproducible test to accurately identify the disease in
its early stages is critical.
The mild pattern of disease in children’s findings is usually subtle
compared to adults, and therefore may not be detected on chest X-ray
(CXR)6. Chest Computed tomography (CT) is undoubtedly
the best imaging modality to accurately assess lung involvement in most
respiratory illnesses, including COVID-19; however, the cost and
possible harmful effects of radiation on a growing child’s body must not
be ignored, as even low-dose ionizing radiations may increase cancer
risk in exposed children 7. In addition, pathologic
findings are often found later in the disease course, and CT is a poor
imaging choice for follow-up or serial imaging 8.
Several studies have shown that lung ultrasound (LUS) is a useful and
accurate tool for detecting pneumonia in children9,10. Other studies
have even shown that LUS can predict more severe pneumonia and monitor
antibiotic response. Recently, different LUS patterns have been used to
differentiate viral from bacterial pneumonia by defining their etiology
in child 11. Although several studies have
investigated LUS in adult COVID-19 patients, the literature for the
pediatric age group is limited12. This study aimed to
review the available evidence of the use of LUS versus CXR and chest CT
in children suspected to have COVID-19 pneumonia and sought to identify
an alternative diagnostic technique that is less invasive than radiation
and more practical in early-stage diagnosis and follow-up monitoring of
COVID-19 pneumonia.