An Observational Study on Diagnostic Accuracy of Lung Ultrasound Compared to High-resolution Computed Tomography Scan of Thorax in Patients Admitted with Respiratory Problems to Critical Care Unit of a Tertiary Care Hospital in Eastern India

Background and aim: Acute respiratory failure in critically ill patients poses a diagnostic challenge, often requiring high-resolution computed tomography (HRCT) of the thorax for definitive diagnosis. However, the inherent risks of transporting hemodynamically unstable patients to the radiology suite necessitate safer bedside alternatives. The objective of the present study was to evaluate the diagnostic yield of both six-zone and extended 12-zone lung ultrasound (LUS) compared to HRCT thorax. Patients and methods: In this cross-sectional observational study conducted on 150 patients, admitted in the critical care unit and surgical intensive care unit (ICU), six-zone and 12-zone LUS were performed within 24 hours of an HRCT thorax for the most common etiologies of respiratory failure. Diagnostic yield of six-zone and 12-zone LUS to HRCT thorax was compared through calculating Cohen's kappa statistic (value ≥ 0.7) being interpreted as indicating strong agreement between two modalities. Results: For consolidation, the 12-zone protocol showed superior sensitivity (0.84 vs 0.76) and negative predictive value (NPV) (0.61 vs 0.47) compared to the six-zone protocol. Agreement with HRCT was "moderate" for the six-zone protocol (kappa = 0.52) but "substantial" for the 12-zone protocol (kappa = 0.81). For pleural effusion and edema, LUS maintained high sensitivity (>0.85). Conclusion: Both LUS protocols are effective, but the 12-zone protocol significantly improves the diagnostic yield for lung consolidation, providing substantial agreement with HRCT. How to cite this article: Dhenki A, Dasgupta S, Choudhury A, Mondal T, Mukhopadhyay S, Bardhan J. An Observational Study on Diagnostic Accuracy of Lung Ultrasound Compared to High-resolution Computed Tomography Scan of Thorax in Patients Admitted with Respiratory Problems to Critical Care Unit of a Tertiary Care Hospital in Eastern India. Indian J Crit Care Med 2026;30(3):237-243.