Low-Dose Chest CT in COVID-19: Diagnostic Performance, Radiation Safety, and Inter-Observer Variability—A Comprehensive Review

Abstract

Background: The use of chest computed tomography (CT) for lung involvement monitoring, disease diagnosis, and severity assessment has expanded dramatically as a result of the COVID-19 epidemic. The need of optimizing radiation doses is highlighted by growing worries about the hazards associated with cumulative radiation exposure, even though chest CT is renowned for its great sensitivity in identifying lung abnormalities related to COVID-19. Although low-dose chest CT (LDCT) has become a viable substitute, further research is needed to fully understand its efficacy, radiation safety, and interpretation variability.

Aim :The goal of this review is to bring together the latest evidence on how well low-dose chest CT performs in diagnosing COVID-19, explore strategies for reducing radiation doses and ensuring safety, and examine how consistently different observers interpret LDCT results.

Methods: In order to do this, we used major medical databases to perform a thorough assessment of the literature, focusing on studies that examined low-dose and ultra-low-dose chest CT in COVID-19 patients. Imaging methods, radiation dose measurements, diagnostic accuracy, observer agreement, and standardized reporting systems were all covered in the articles we included. The results of observational research, comparative analyses, and consensus guidelines were all rigorously examined.

Results: Our findings demonstrate that utilizing radiation doses far lower than those of standard-dose CT, LDCT maintains a high degree of diagnostic accuracy for identifying frequent COVID-19 lung abnormalities, such as ground-glass opacities, consolidation, and bilateral peripheral involvement. Additionally, sophisticated reconstruction methods lower noise and enhance image quality. While there is modest agreement for more subtle findings such interlobular septal thickness and early fibrotic alterations, the majority of studies show excellent agreement among observers regarding significant CT features. To reduce interpretation variability, radiologists' experience and the use of standardized reporting systems, including CO-RADS and RSNA recommendations, are crucial.

Conclusion: Low-dose chest CT strikes a remarkable balance between radiation safety and diagnostic accuracy, making it a safe and useful imaging technique for evaluating COVID-19. We can further increase the trustworthiness of interpretations by regularly implementing dose-optimized protocols, organized reporting, and targeted training. These observations support the broader use of LDCT in routine clinical practice, particularly in high-volume and follow-up imaging scenarios.