Is Lung Ultrasound Imaging a Worthwhile Procedure for Severe Acute Respiratory Syndrome Coronavirus 2 Pneumonia Detection?

Objectives: We compared 2 imaging modalities in patients suspected of having coronavirus disease 2019 (COVID-19) pneumonia. Blinded to the results of real-time reverse transcriptase polymerase chain reaction (rRT-PCR) testing, lung ultrasound (LUS) examinations and chest computed tomography (CT) were performed, and the specific characteristics of these imaging studies were assessed.

Methods: From March 15, 2020, to April 15, 2020, 63 consecutive patients were enrolled in this prospective pilot study. All patients underwent hematochemical tests, LUS examinations, chest CT, and confirmatory rRT-PCR. The diagnostic performance of LUS and chest CT was calculated with rRT-PCR as a reference. The interobserver agreement of radiologists and ultrasound examiners was calculated. Ultrasound and CT features were compared to assess the sensitivity, specificity, positive predictive value, and negative predictive value. Positive and negative likelihood ratios measured the diagnostic accuracy.

Results: Nineteen (30%) patients were COVID-19 negative, and 44 (70%) were positive. No differences in demographics and clinical data at presentation were observed among positive and negative patients. Interobserver agreement for CT had a κ value of 0.877, whereas for LUS, it was 0.714. The sensitivity, specificity, positive predictive value, and negative predictive value of chest CT for COVID-19 pneumonia were 93%, 90%, 85%, and 95%, respectively; whereas for LUS, they were 68%, 79%, 88%, and 52%. On receiver operating characteristic curves, area under the curve values were 0.834 (95% confidence interval, 0.711-0.958) and 0.745 (95% confidence interval, 0.606-0.884) for chest CT and LUS.

Conclusions: Lung ultrasound had good reliability compared to chest CT. Therefore, our results indicate that LUS may be used to assess patients suspected of having COVID-19 pneumonia.