Secondary Logo

Journal Logo

Institutional members access full text with Ovid®

Global and Regional Diagnostic Accuracy of Lung Ultrasound Compared to CT in Patients With Acute Respiratory Distress Syndrome*

Chiumello, Davide MD1–3; Umbrello, Michele MD1; Sferrazza Papa, Giuseppe Francesco MD2; Angileri, Alessio MD4; Gurgitano, Martina MD5; Formenti, Paolo MD1; Coppola, Silvia MD1; Froio, Sara MD1; Cammaroto, Antonio MD2; Carrafiello, Gianpaolo MD4

doi: 10.1097/CCM.0000000000003971
Clinical Investigations

Objectives: Lung CT is the reference imaging technique for acute respiratory distress syndrome, but requires transportation outside the intensive care and x-ray exposure. Lung ultrasound is a promising, inexpensive, radiation-free, tool for bedside imaging. Aim of the present study was to compare the global and regional diagnostic accuracy of lung ultrasound and CT scan.

Design: A prospective, observational study.

Setting: Intensive care and radiology departments of a University hospital.

Patients: Thirty-two sedated, paralyzed acute respiratory distress syndrome patients (age 65 ± 14 yr, body mass index 25.9 ± 6.5 kg/m2, and Pao2/Fio2 139 ± 47).

Interventions: Lung CT scan and lung ultrasound were performed at positive end-expiratory pressure 5 cm H2O. A standardized assessment of six regions per hemithorax was used; each region was classified for the presence of normal aeration, alveolar-interstitial syndrome, consolidation, and pleural effusion. Agreement between the two techniques was calculated, and diagnostic variables were assessed for lung ultrasound using lung CT as a reference.

Measurements and Main Results: Global agreement between lung ultrasound and CT ranged from 0.640 (0.391–0.889) to 0.934 (0.605–1.000) and was on average 0.775 (0.577–0.973). The overall sensitivity and specificity of lung ultrasound ranged from 82.7% to 92.3% and from 90.2% to 98.6%, respectively. Similar results were found with regional analysis. The diagnostic accuracy of lung ultrasound was significantly higher when those patterns not reaching the pleural surface were excluded (area under the receiver operating characteristic curve: alveolar-interstitial syndrome 0.854 [0.821–0.887] vs 0.903 [0.852–0.954]; p = 0.049 and consolidation 0.851 [0.818–0.884] vs 0.896 [0.862–0.929]; p = 0.044).

Conclusions: Lung ultrasound is a reproducible, sensitive, and specific tool, which allows for bedside detections of the morphologic patterns in acute respiratory distress syndrome. The presence of deep lung alterations may impact the diagnostic performance of this technique.

1SC Anestesia e Rianimazione, Ospedale San Paolo – Polo Universitario, ASST Santi Paolo e Carlo, Milan, Italy.

2Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy.

3Centro Ricerca Coordinata di Insufficienza Respiratoria, Università degli Studi di Milano, Milan, Italy.

4UO Radiologia Diagnostica e Interventistica, Ospedale San Paolo – Polo Universitario, ASST Santi Paolo e Carlo, via A. di Rudinì 8, 20142, Milan, Italy.

5Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Milan, Italy.

*See also p. 1669.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (

The authors have disclosed that they do not have any potential conflicts of interest.

For information regarding this article, E-mail:

Copyright © 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.