Lung ultrasound and high-resolution CT-scan of the chest for COVID-19 pneumonia

Background: Lung ultrasound (LUS) has been reported as a useful tool to intercept lung peripheral changes (LPC) in COVID-19 pneumonia. Viral pneumonia by Sars-Cov-2 is characterized by alveolar exudation and damage, interstitial thickening with patchy distribution with centrifugal extension and subpleural involvement. Methods: COVID-19 pneumonia patients underwent LUS using a standard sequence of scans in 14 landmarks. A score ranging from 0 to 3, according to Soldati’s proposal, was reported for each landmark. High-resolution CT-scan of the chest (HRCT) was performed within 48 hours prior to or after LUS. For each corresponding HRCT area, was reported a score (0 normal peripheral lung, 1 minimal LPC, 2 peripheral ground glass opacities (GGOs), 3 peripheral lung consolidations with or without GGOs) Results: Sixteen confirmed COVID-19 pneumonia underwent LUS. LUS showed sensitivity 92.1%, specificity 90%, PPV 96.8% to intercept any peripheral alterations on HRCT (both LUS and HRCT scores ≠0). Higher LUS scores (2-3), corresponding to worst changes, showed sensitivity 70.1%, specificity 84%, PPV 78.1% to intercept higher HRCT scores (2-3). The overall score, for both LUS and HRCT, over 14 landmarks, showed no significant differences (paired t-test p=0.055). An overall score ≥24 was reported in 5 cases by LUS and 6 cases by HRCT. No significant differences also for patients either with more than 3 landmarks with score 3 or with 8 landmarks out of 14 with score 2-3 (p=0.16). Conclusions: LUS showed good sensitivities and specificities compared to HRCT to intercept peripheral changes in COVID-19 pneumonia.