Diagnosing COVID-19 pneumonia in a pandemic setting: Lung Ultrasound versus CT (LUVCT) – a multicentre, prospective, observational study

Abstract

BackgroundIn this COVID-19 pandemic, fast and accurate testing is needed to profile patients at the emergency department (ED) and efficiently allocate resources. Chest imaging has been considered in COVID-19 workup, but evidence on lung ultrasound (LUS) is sparse. We therefore aimed to assess and compare the diagnostic accuracy of LUS and computed tomography (CT) in suspected COVID-19 patients.MethodsThis multi-centre, prospective, observational study included adult patients with suspected COVID-19 referred to internal medicine at the ED. We calculated diagnostic accuracy measures for LUS and CT using both PCR and multi-disciplinary team (MDT) diagnosis as reference. We also assessed agreement between LUS and CT, and between sonographers.ResultsBetween March 19 and May 4, 2020, 187 patients were included. Area under the receiver operating characteristic (AUROC) was 0.81 (CI 0.75–0.88) for LUS and 0.89 (CI 0.84–0.94) for CT. Sensitivity and specificity for LUS were 91.9% (CI 84.0–96.7) and 71.0% (CI 61.1–79.6), versus 88.4% (CI 79.7–94.3) and 82.0% (CI 73.1–89.0) for CT. Negative likelihood ratio was 0.1 (CI 0.06–0.24) for LUS and 0.14 (0.08–0.3) for CT. No patient with a false negative LUS, required supplemental oxygen or admission. LUS specificity increased to 80% (CI 69.9–87.9) compared to MDT diagnosis, with an AUROC of 0.85 (CI 0.79–0.91). Agreement between LUS and CT was 0.65. Inter-observer agreement for LUS was good: 0.89 (CI 0.83–0.93).ConclusionLUS and CT have comparable diagnostic accuracy for COVID-19 pneumonia. LUS can safely exclude clinically relevant COVID-19 pneumonia and may aid COVID-19 diagnosis in high prevalence situations.

Chest CT in COVID-19 at the ED: Validation of the COVID-19 Reporting and Data System (CO-RADS) and CT Severity Score

“…We have seen significant health disparities in COVID-19 outcome along geographic, socioeconomic, ethnic, cultural, and racial lines. [28][29][30][31] Portable imaging modalities such as bedside lung ultrasound circumvent these issues, while showing better accuracy than CXR and similar accuracy to CT. 10,[32][33][34][35][36][37][38][39][40][41][42][43] This may be considered as a viable alternative, especially in low-resource settings where CT might not be readily available.…”

Low Sensitivity of Admission Lung US Compared to Chest CT for Diagnosis of Lung Involvement in a Cohort of 82 Patients with COVID-19 Pneumonia

“…A large multicentric study by Yasukawa et al [ 26 ] found that LUS and CT have comparable diagnostic accuracy for COVID-19 pneumonia, with LUS reaching a sensitivity of 92% compared to PCR as a reference standard. In comparison to this study, the lower prevalence of lung abnormalities detected by LUS in our case series may be explained by the fact that a larger number of patients had very mild abnormalities on CT-scan or, anyhow, showed lesions that hardly reached the pleura, thus undetectable via LUS.…”

On the Role of Artificial Intelligence in Medical Imaging of COVID-19

“…It was described as a preferred modality in Italy 52 during spring 2020, but it is not used as extensively in other geographies, mainly applied for patients with CT/CXR contraindications (children, pregnant women) and predestined to study solid organs unlike the lung. Some reported higher sensitivity than CXR in COVID-19 diagnosis 53 , or even comparable diagnostic accuracy to CT 54,55 , but the role of LUS for the COVID-19 pandemic is still actively debated in the literature 56,57,58 . A summary of the differences between the imaging modalities is provided in Table 2.…”