Frequency of Atypical Pulmonary Manifestations of COVID-19 Patients on Chest CT-scan: A cross-sectional study

Background Chest CT examination is significant in COVID-19 diagnosis due to its high sensitivity. Although typical chest CT findings have been discussed thoroughly in the literature throughout the pandemic, we aimed to investigate the prevalence of the atypical conclusions during the start of the Omicron variant insurgency and compare the results to studies conducted before its outbreak. Methods 606 confirmed COVID-19 cases were included in this study based on inclusion and exclusion criteria during January and February 2022. Demographic information of patients, including age and sex, was recorded. The computed tomography (CT) examination was carried out using a 100-slice scanner (Philips Brilliance 6 CT Scanner). One radiology attending and one resident evaluated SARS-CoV-2 RT-PCR-positive patients for atypical pulmonary CT findings. The obtained data were evaluated using R software version 4.1.1. Results 55% of patients were female, and the median age was 56 (IQR: 42, 69) 59% of patients had atypical findings on their pulmonary CT examination. These findings showed that pleural abnormalities were the most frequent atypical findings, with pleural thickening being the most common (17%). The double halo sign represented the least frequent atypical sign (0.2%). Conclusion Atypical findings were more prevalent in this study than its predecessors, while we acknowledge that other factors, such as study design and patient population, could have impacted it. The presence of atypical signs generally was not correlated with specific demographic groups, while some of these signs were more frequent in some groups.