Thoracic Ultrasound

The clinical benefits of LUS manifest in patients ranging from the clinically ill to those who have suffered trauma. Along with the proper hands-on technique at the bedside, the different US modalities and parameters of the US machine must be understood in order to acquire high-quality images on the screen for the physician to translate clinically. Unlike other parts of the body, the normal healthy lungs themselves are not actually visualised using bedside US, and what is depicted on the screen is not a true representation of the lung. Instead, LUS can best be described as the interpretation of US artefacts. Accordingly, the basic US principles and physics behind these artefacts must be understood in order to learn, apply and teach LUS. These tenets are reflected in both normal lung (e.g. A-lines, mirror artefact of the liver above the diaphragm) and diseased or injured lung (e.g. B-lines, pneumothorax).

Cite as: Alerhand S, Graumann O, Nelson BP. Physics and basic principles. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 1–13 [https://doi.org/10.1183/2312508X.10006017].

US examination of the chest wall and parietal pleura can reveal a number of pathologies and is useful in various clinical settings. Chest wall pathologies that are identifiable during US examination include haematomas, abscesses, rib abnormalities and lymph nodes. Additionally, useful information about pleural infection and neoplasia can be gathered using US. In addition to its diagnostic potential, US provides guidance for safe execution of percutaneous sampling and/or drainage of chest wall and pleural abnormalities.

Cite as: Hassan M, Rahman NM. Chest wall and parietal pleura. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 31–42 [https://doi.org/10.1183/2312508X.10006217].

Pleural effusions represent a significant disease burden globally. TUS, performed by both radiologists and physicians, has increasingly become an essential tool in the evaluation and management of pleural effusions. It detects pleural effusions with higher sensitivity and specificity than CXR, and provides valuable information about the size and depth of the pleural effusion, the echogenicity of the fluid, the presence of septated or loculated fluid, pleural thickening and nodularity, and the presence of any contralateral pleural effusion. TUS can provide information on diaphragm position and movement with respiration, and can assess the presence of lung sliding and the accessibility of pockets of fluid in loculated pleural effusions, thereby improving the success rate and safety of pleural procedures. Given the added detail that US provides and its increasing availability, it is no surprise that its use is increasingly expanding in clinical practice.

Cite as: Merrick C, Asciak R, Edey A, et al. Pleural effusion. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 64–74 [https://doi.org/10.1183/2312508X.10014817].

Several studies suggest that LUS could be useful for the diagnosis of pneumonia. It also has a more favourable safety profile and a lower cost than chest radiography or CT. The characteristic sonographic signs of pneumonia are a hypoechoic liver- or tissue-like subpleural consolidation and a marked dynamic bronchoaerogram. The borders are blurred and serrated, often accompanied by comet tail artefacts. A parapneumonic effusion can be detected in 55% of cases. Abscess formations are better seen in LUS than in CXR. They can be treated under US guidance. LUS cannot rule out pneumonia. However, accuracy is >90%. These patients should therefore be treated immediately according to clinical presentation and laboratory findings, without further imaging procedures. In cases of tuberculosis and diseases of the frame of the lung, sonography is the optimum method of visualising small pleural effusions and subpleural consolidations.

Cite as: Mathis G. Pneumonia. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 87–101 [https://doi.org/10.1183/2312508X.10006617].

The diagnostic value of TUS of lung tumours, especially bronchial carcinomas, is limited and dependent on the localisation of the tumour. Focused clinical use is to be distinguished in the context of primary diagnosis, staging, therapy response and tumour growth. Symptom-oriented practice is important at the bedside for palliative patients, in point-of-care sonography, in the emergency room and in intensive care units. Different US-based procedures, such as transcutaneous US, EUS and EBUS are used for distinct approaches to lung tumours. B-mode imaging, colour Doppler sonography, CEUS and US-controlled interventions are the sonographic modalities used in daily clinical practice and for special clinical questions. In special clinical indications, US is the primary guideline diagnostic procedure. Transthoracic LUS is limited by physical factors such as absorption and reflection and, in principle, by a high interobserver variability, as well as differences in device and examining competence.

Cite as: Görg C, Trenker C, Schuler A. Lung tumours. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 115–128 [https://doi.org/10.1183/2312508X.10006817].

When carrying out an US scan of the thorax, the examiner will also detect structures in the upper abdomen. Incidental abdominal pathologies may be detected with varying frequency during TUS. In this chapter, we provide an overview of the most common pathologies. Clinicians should be aware of the technical challenges when interpreting abnormal US patterns. Examiners who normally only examine the thorax may not be familiar with the abdominal organs. It is therefore essential that a specialist opinion is requested when a possible pathology is detected.

Cite as: Posth S, Graumann O. The upper abdomen. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 148–160 [https://doi.org/10.1183/2312508X.10007417].

US is an important tool in the provision of safer airway management for patients. Using a high-frequency linear probe affixed to conventional bedside portable US machines, the patient's upper airways from the mandible to the jugular notch can be depicted with US such that when the US beam penetrates to the luminal surface of the airway, as for example in the trachea, a strong echo arises yielding a distinct hyperechoic white line on the screen, the “tissue–air border”, and everything beyond that visualised on the screen is mere artefact. There are numerous indications for the use of US for airway management; only the most clinically valuable will be described in detail in this chapter. These include: US identification of the cricothyroid membrane in preparation for management of a difficult airway where emergency airway access via the anterior neck might become necessary, identification of the ideal interspace between tracheal rings for tracheostomy, and simultaneous scanning of the trachea and oesophagus just cranial to the jugular notch to observe whether a tube enters the airway or the oesophagus.

Cite as: Kristensen MS, Teoh WH. Ultrasound of the neck for airway management. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 172–183 [https://doi.org/10.1183/2312508X.10007517].

Chest US is a rapidly growing field in the imaging of the developing human, and is based on the same images and artefacts employed by adult emergency physicians. Solid evidence has recently been published about the US features of respiratory distress syndrome, transient tachypnea of the neonate and meconium aspiration syndrome. Tension pneumothorax can be accurately diagnosed with US and rapidly treated. Research into endotracheal tube positioning and chronic lung disease is ongoing. Semiquantification of the US signal has generated an intriguing comparison with the conventional radiogram with regard to the role of the first-line technique in several respiratory diagnoses. In the infant and the child, LUS can be applied in the work up of lung consolidations and several groups have investigated its accuracy in diagnosing pneumonia and bronchiolitis. Further paediatric applications include the study of chest wall masses and pleural effusions; focused assessment with sonography for trauma protocol remains an important area of current investigation.

Cite as: Raimondi F, Migliaro F, Giannattasio A, et al. Newborns, infants and children. In: Laursen CB, Rahman NM, Volpicelli G, eds. Thoracic Ultrasound (ERS Monograph). Sheffield, European Respiratory Society, 2018; pp. 206–225 [https://doi.org/10.1183/2312508X.10007217].