Abstract
BACKGROUND AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic and associated nonpharmaceutical interventions, including mask-wearing and hand hygiene, have led to a global decline in otorhinolaryngologic conditions, with the monthly incidence of chronic rhinosinusitis decreasing from 39.49 to 14.56 per 100,000 people. This study compared the prevalence and severity of paranasal sinus abnormalities observed on magnetic resonance imaging (MRI) before and during the COVID-19 pandemic. METHODS: This retrospective study analyzed brain MRI scans from 3,762 individuals (1,881 men and 1,881 women; mean age, 56.2±9.8 years) performed at a single health-screening center in Seoul, South Korea, between January 2018 and December 2022. The study period was divided into pre-COVID-19 and COVID-19 phases, with March 2020 as the cutoff. A total of 428 scans demonstrating incidental paranasal sinus abnormalities, including mucosal thickening, retention cysts or polyps, fluid collection, and fungal balls, were evaluated using the Lund-Mackay (LM) scoring system. RESULTS: The overall prevalence of incidental paranasal sinus abnormalities was 11.4% (428/3,762), with a significant decline from the pre-COVID-19 to the COVID-19 period (16.1% vs. 8.6%, p<0.001). However, the mean LM score among participants with abnormalities was significantly higher during the COVID-19 period than in the pre-COVID-19 period (3.64±3.22 vs. 3.01±2.58, p=0.026). The proportion of nasal polyps was also greater during the COVID-19 period than in the pre-COVID-19 period (10.8% vs. 5.8%, p=0.028). CONCLUSION: The prevalence of incidental paranasal sinus abnormalities on MRI decreased during the COVID-19 period compared to the pre-COVID-19 period, whereas the severity, as reflected by the LM score, increased.