Lung Ultrasound vs Thoracic CT for Diagnosing COVID-19 Pneumonia

Lung ultrasound offers a noninvasive, effective diagnostic tool for monitoring evolution and stratifying the prognosis of patients with COVID-19 pneumonia, according to study findings published in Respiratory Investigation.

Researchers sought to evaluate the diagnostic accuracy of lung ultrasound (LUS) compared with thoracic computed tomography (CT) to determine severity of COVID-19 pneumonia. They also hoped to show correlations between LUS score, percutaneous oxygen saturation (SpO₂), and inflammatory markers.

The researchers conducted a prospective observational study at Târgu-Mureș Pulmonology Clinic, Mureș County Clinical Hospital, Romania, between January 2021 and March 2021. The study analyzed data from adult 48 patients diagnosed with severe acute SARS-CoV-2 infection and a clinically active respiratory infection. All participants experienced LUS, CT, and blood tests upon admission.

Researchers found LUS showed subpleural consolidations (70.8%), pleural irregularities with thickening/discontinuity (75%), and bilateral B-lines (97.8%). Uncommon sonographic patterns were alveolar consolidations with pleural effusion (2%), and bronchogram (33%). They noted that LUS score cutoff values equal to or less than 14 and greater than 22 predicted mild COVID-19 (sensitivity [Se]=84.6%; area under the curve [AUC]=0.72; P =.002) and severe COVID-19 (Se=50%, specificity (Sp)=91.2%, AUC=0.69; P =.02), respectively, and values greater than 29 predicted the patients’ transfer to intensive care (Se=80%, Sp=97.7%).

According to researchers, LUS score positively correlated with CT score (r=0.41; P =.003) and increased with the decrease of SpO₂ (r= -0.49; P =.003), with lymphocytes decline (r= -0.52; P =.0001). They added that patients with consolidation patterns had higher C-reactive protein and ferritin than those with B-line patterns (P =.03; P =.01, respectively).

Study limitations include the observational nature lacking randomization or blinding, small sample size, selection bias, and the lack of a convex transducer.

Researchers concluded that, “LUS is a useful, noninvasive and effective tool for diagnosis, monitoring evolution, and prognostic stratification of COVID-19 patients.” They added that “LUS had good diagnostic accuracy, highlighted by higher sensitivity and specificity in the detection of COVID-19 severity types and predicting the ICU transfer of critical patients.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Ciurba BE, Sárközi HK, Szabó IA, et al. Applicability of lung ultrasound in the assessment of COVID-19 pneumonia: Diagnostic accuracy and clinical correlations. Respir Investig. Published online August 8, 2022. doi:10.1016/j.resinv.2022.06.015