Lung Ultrasound: The Essentials

Abstract

L ung US has dramatically increased in popularity over the last decade and is routinely performed at the patient's bedside, especially in the emergency department and the intensive care unit (ICU) (1-3). Formal training in the performance and interpretation of lung US, however, is not a traditional component of radiology residency education in the United States. As this modality becomes an imaging staple, the diagnostic radiologist should be fluent in lung US performance and interpretation to maintain relevance and assist the ordering clinician. In this imaging essay, the essentials of lung US are described and radiographic correlation for lung US imaging findings on chest radiographs and chest CT images is provided. A discussion of the role of lung US in health care delivery and the future directions of lung US is also included. Utility of Lung USLung US is radiation-free, low-cost, rapid, and portable, allowing real-time examination of pulmonary structures. Meta-analyses suggest that compared with chest radiography, lung US may have higher sensitivity and similar specificity for detection of pleural effusion, pneumonia, pneumothorax, and pulmonary edema (Table ) (4-7). It is increasingly used in the ICU to detect these diseases. Critical care providers have adopted the bedside lung US in emergency (BLUE) protocol as a standardized approach to lung US in the ICU. This protocol can be performed in less than 3 minutes at the bedside and has a diagnostic accuracy greater than 90% for asthma and/ or chronic obstructive pulmonary disease, pneumonia, pneumothorax, pulmonary edema, and pulmonary embolism (1,8). The accuracy for pulmonary embolism derives from the protocol directing the provider to examine the deep venous structures if there is no sign of pulmonary disease. Many practitioners have advocated for the regular use of lung US in the ICU to decrease the use of chest radiography, which is associated with This copy is for personal use only. To order printed copies, contact reprints@rsna.org Although US of the lungs is increasingly used clinically, diagnostic radiologists are not routinely trained in its use and interpretation. Lung US is a highly sensitive and specific modality that aids in the evaluation of the lungs for many different abnormalities, including pneumonia, pleural effusion, pulmonary edema, and pneumothorax. This review provides an overview of lung US to equip the diagnostic radiologist with knowledge needed to interpret this increasingly used modality.

Echogenic swirling pattern, carcinoembryonic antigen, and lactate dehydrogenase in the diagnosis of malignant pleural effusion

“…Most of these methods require specific laboratory analysis or high-end equipment, limiting their clinical applications. Real-time ultrasonography of the chest is a convenient method to detect pleural effusion, and its techniques have been intensively reviewed 11 , 29 – 31 . In this study, we showed the possibility of combining the echogenic swirling pattern, pleural CEA, and pleural LDH in MPE diagnosis.…”

Ultrasonography in the Evaluation of Pediatric Chest “Masses”: When to Consider?

“…Examination can be done in supine or upright position. 1 Multiple acoustic windows are available as described briefly in Table 2. 4,6 However, when a mass detected on CXR/CT needs evaluation, the examination needs to be tailored according to the findings on the CXR/CT.…”

“…So the lung pathologies are diagnosed when air at pleural interface is replaced by fluid/soft tissue reducing acoustic mismatch or alteration in naturally occurring artifacts 4 . Various signs and artifacts pertaining to normal appearances in a chest ultrasound have been widely described in literature as summarized in Table 1 1,4,5 …”

“…Focused lung ultrasound requires evaluation of each hemithorax in three zones—anterior, lateral and posterior. Examination can be done in supine or upright position 1 . Multiple acoustic windows are available as described briefly in Table 2 4,6 .…”

“…Ultrasound is a very valuable modality, especially in the pediatric age group; however, its application in thorax is relatively underutilized. Adequate training and sound knowledge of anatomy can increase the diagnostic yield of thoracic ultrasound 1 …”