Chest
ReviewsReal-Time Chest Ultrasonography: A Comprehensive Review for the Pulmonologist
Section snippets
Technical Equipment
Visualization of the chest wall requires a higher frequency linear probe (5 to 7.5 MHz), whereas pleural and pulmonary pathology is better detected with a sector or phased array probe with lower frequency (3.5 MHz).3,4 A convex array probe (3.5 to 5 MHz) combines the advantage of adequate close resolution and the ability to access deeper structures between the ribs. All described examinations were performed by a pulmonologist. Recently developed, and still expensive, devices having
The Technique of US Examination
To examine anterior and posterior parts of the chest, the patient should be in a sitting position with arms elevated and hands clasped behind the neck (Fig 1). Even with this technique, some parts of the upper lobes remain hidden behind the scapulae. Pleural movement is observed during inspiration and expiration. Solid lesions close to the diaphragm require special maneuvers, such as sniffing or coughing. The probe may be moved in longitudinal and transverse directions to visualize the lung
Chest Wall
Numerous studies5,6,7 evaluating US chest wall imaging have been published. The visibility of muscle and bone has steadily increased with equipment advances (Table 1). Different parts of the chest wall may now be well-delineated with current techniques (Fig 1). The margins of normal ribs are outlined as uninterrupted echogenicities similar to normal pleura, while the pleura is moving continuously during respiration. The US beam passes through cartilage better than through muscular tissue.
Normal US Findings
Less than 1 mm of space is usually present between the parietal and visceral pleura. A thin echogenic lining represents parietal pleura. The visceral pleura may be slightly blurred due to reflection artifacts from the US beam as it encounters a lung surface. Both pleural surfaces may rarely be visualized on standard US pictures. However, the parietal pleura does not move, whereas the visceral pleura moves with respiration.
Pleural Effusion
US imaging is the best method for diagnosing pleural effusion and
Comparison of US With Other Imaging Methods
US is more sensitive than posterior-anterior and lateral chest radiographs in detecting small amounts of pleural fluid.31 Pleural fluid is even more difficult to discern on radiographs taken with the patient in the supine position.17,32 On decubital chest radiographs, the differentiation between atelectasis and effusion is occasionally difficult. US better estimates the volume of effusion than radiography.32 US is useful to evaluate pleural opacities by differentiating atelectasis, effusion,
Pulmonary Embolism
A variety of imaging techniques for patients with pulmonary embolism (PE) has been studied. The first step in the diagnosis is the chest radiograph. It shows infiltrates, atelectasis, and effusions.39 Ventilation-perfusion scintigraphy is the next step in many institutions. However, the investigators in the Prospective Investigation of Pulmonary Embolism Diagnosis study40 found that only a minority of patients with PE had high-probability scans (sensitivity, 41%; specificity, 97%). One hundred
Pneumonia
Peripheral pulmonary lesions that extend into the visceral pleura may be visualized by US. US differentiates atelectasis and effusion when opacities are present. Inflamed lung parenchyma shows hypoechoic consolidation with blurred margins. The echo-texture is homogeneous and occasionally mimics lung parenchyma, with multiple lentil-sized air inlets.59,60 Echo-texture varies with ventilation. It is heterogeneous with ventilation or homogeneous with small or absent air inlets. The air bronchogram
Transthoracic US of the Mediastinum
The most common disorders of the mediastinum in adults are metastasis and primary malignancy. Benign disorders, such as cysts, thymomas, or lipomas, are rare.88,89 The imaging technique designated for evaluating the mediastinum is chest radiography, followed by CT scanning. Although an adequate view of the mediastinum is somewhat impaired by bone, US plays a useful role. In 1971, Goldberg90 first described suprasternal US of the mediastinum. Cardiologists used this access to examine the aortic
US-Guided Biopsy
For many years, pulmonologists were limited to the use of fluoroscopy-guided transthoracic biopsies. The introduction of CT scanning in the 1980s allowed clinicians to increase the range of biopsies. Real-time US-guided biopsy of the chest wall or pleural lesions has been performed for years.106 Encouraging results for chest wall lesions,107,108 pleural lesions,109 pulmonary lesions,110,111 and mediastinal lesions112,113,114 have been reported. US-guided aspiration biopsy is successful with
US in the ICU
Bedside US offers many possibilities in the ICU setting. Critically ill patients receiving positive-pressure ventilation may develop life-threatening complications during transport or during positioning in the CT scanning or MRI suite. Rapid diagnosis is crucial in deteriorating patients and in acute emergencies. US is invaluable for the immediate detection of pericardial or pleural effusions. The differential diagnosis of pleural fluid may be easily achieved133 (eg, hemothorax simulating liver
Summary
New imaging techniques have considerably improved the diagnostic and therapeutic capabilities of the pulmonologist.139 US has a valuable role, yet, it is operator-dependent, and training is required. It is a supplement for areas requiring more detailed views. Bedside availability and the absence of radiation allow more patients to be suitable candidates. A diagnosis of liquid or solid masses is easily achieved, and thoracentesis is performed with a low risk of complications. Pulmonary lesions
References (139)
Sonography of the chest wall
Eur J Ultrasound
(1996)Thorax sonography: part I. Chest wall and pleura
Ultrasound Med Biol
(1997)- et al.
Ultrasonographic approach to diagnosing chest wall tumors
Chest
(1988) Chest wall and lung surface viewing with ultrasound
Chest
(1988)- et al.
Ultrasonographic evaluation of pleural and chest wall invasion of lung cancer
Chest
(1988) - et al.
Diagnosis of pleural effusions: experience with clinical studies, 1986–90
Chest
(1995) - et al.
An evaluation of the new Olympus LTF semiflexible thoracofiberscope and comparison with Abram's needle biopsy
Chest
(1998) - et al.
Accuracy of CT for the detection of pleural adhesions: correlation with video-assisted thoracoscopic surgery
Chest
(1999) - et al.
Multimodality management of malignant pleural mesothelioma
Chest
(1998) - et al.
Frequency of pulmonary embolism in patients with low-probability lung scan and negative lower extremity venous ultrasound
Chest
(1999)
Thrombolytic therapy of pulmonary embolism: a comprehensive review of current evidence
Chest
Pulmonary infarction: sonographic appearance with pathologic correlation
Eur J Radiol
Ultrasound pictures of pneumonia
Eur J Ultrasound
Thoraxsonography: part II. Peripheral pulmonary consolidation
Ultrasound Med Biol
Diagnostic and management strategies for diffuse interstitial lung disease
Chest
Color Doppler ultrasound pulsatile flow signals of thoracic lesions: comparison of lung cancers and benign lesions
Ultrasound Med Biol
The role of thoracoscopy in lung cancer management
Chest
Video-assisted thoracoscopic surgery for small indeterminate pulmonary nodules: indications for preoperative marking
Chest
Diagnosis of dissecting aortic aneurysm with suprasternal echocardiography
Am J Cardiol
Transthoracic sonography of the mediastinum
Eur J Ultrasound
Evaluation of ultrasonically guided biopsies of mediastinal masses
Chest
Future directions of research in thoracic imaging
Radiology
Future directions in pulmonary imaging
Radiology
Simple measurement of chest wall thickness with ultrasound
Radiology
Tumor invasion of the chest wall in lung cancer: diagnosis with US
Radiology
Chest wall and mediastinal invasion by lung cancer: evaluation with multisection expiratory dynamic CT
Radiology
Brachial plexus: correlation of MR imaging with CT and pathologic findings
Radiology
Chest wall invasion by bronchogenic carcinoma: evaluation with MR imaging
Radiology
Superior pulmonary sulcus tumors and Pancoast's syndrome
N Engl J Med
Thoracic imaging
Pleural fluid dynamics and effusions
Radiographic techniques
Sonographic imaging of the pleura: nearly 30 years experience
Eur J Ultrasound
Tuberculous pleural effusions: ultrasonic diagnosis
J Clin Ultrasound
Disorders of the pleura: general principles and diagnostic approach
Pleural and other investigations
Current management of pleural disease
Br J Hosp Med
Image-guided pleural biopsies: indications, technique, and results in 23 patients
Radiology
Image comparison of real-time gray-scale ultrasound and color Doppler ultrasound for use in diagnosis of minimal pleural effusion
Am J Respir Crit Care Med
Metastases to the pleura: sonographic detection
J Clin Ultrasound
Pleural effusion: an “acoustic window” for sonography of pleural metastases
J Clin Ultrasound
Malignant pleural mesothelioma: US-guided histologic core-needle biopsy
Radiology
Sonographic examination of diaphragmatic pleura in tumour patients
Ultraschall Med
Minimal detectable pleural effusions
Radiology
Quantification of pleural effusion: sonography versus radiography
Radiology
CT in differential diagnosis of diffuse pleural disease
AJR Am J Roentgenol
Thoracoscopy: present diagnostic and therapeutic indications
Eur Respir J
MRI, CT and sonography in the preoperative evaluation of primary tumor extension in malignant pleural mesothelioma
Rofo Fortschr Geb Rontgenstr Neuen Bildgeb Verfahr
Cited by (153)
Clinical applications of pulmonary ultrasound
2020, Medicina ClinicaUltrasound-Guided Regional Anesthesia
2019, A Practice of Anesthesia for Infants and ChildrenPoint-of-Care Ultrasound in the Intensive Care Unit
2018, Clinics in Chest MedicineUltrasound-Guided Regional Anesthesia
2018, A Practice of Anesthesia for Infants and Children
This work was supported by the Division of Pulmonary Medicine, Center of Internal Medicine, Nuremberg, Germany.