The chest radiographic scoring system in initial diagnosis of COVID-19: Is a radiologist needed?

Background: Lung imaging, next to a polymerase chain reaction (PCR) test, is a key diagnostic tool in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The degree of abnormalities correlates with clinical outcome. Imaging of the lungs using chest radiography (CXR) at the peak of a pandemic is considered a basic diagnostic tool at the triage stage. The CXR images are less characteristic than computed tomography (CT) and should be interpreted with a combination of clinical findings.

Objectives: Comparison of the usefulness of 2 CXR severity scores to evaluate the presence/severity of inflammation in the course of COVID-19 and the possibility of a non-radiologist to interpret the image independently.

Material And Methods: Retrospective analysis of the medical records of 152 consecutive patients (aged 19-96, 73 men), infected with SARS-CoV-2, confirmed using real-time PCR (RT-PCR). Five-point and twelve-point CXR severity scoring systems were used (independently by a radiologist and a referring physician) to assess the severity of inflammation.

Results: In 77 of 152 cases, the CXR revealed features of inflammation. Bilateral abnormalities were found in 48/77 (62.3%) cases. Statistically, the lower lobes were involved more often than the upper ones (p < 0.001) and the left lobe more often than the right one (p < 0.001). The intensity of the abnormalities using both scales correlated with the persistence of symptoms (p = 0.0133 and p = 0.0403). A positive and statistically significant correlation was found between both scales and dyspnea, decreased oxygen saturation, elevated C-reactive protein (CRP), ferritin, D-dimer, lactate dehydrogenase, and alanine aminotransferase activity. The interobserver agreement analysis did not show a statistically significant difference in the CXR severity score using the five-point (B = 0.8345, kappa = 0.82; p = 0.1480) or the twelve-point scale (B = 0.8219, kappa = 0.77; p = 0.0502).

Conclusions: The CXR severity score is a useful tool to assess the inflammation in the initial diagnosis of coronavirus disease 2019 (COVID-19). Quantifying lung abnormalities accurately may be performed by a referring physician. Both CXR severity scales correlate well with clinical parameters.