Ecografía torácica

Conventional and Contrast-enhanced US of the Lung: From Performance to Diagnosis

In recent years, lung US has evolved from a marginal tool to an integral component of diagnostic chest imaging. Contrast-enhanced US (CEUS) can improve routine gray-scale imaging of the lung and chest, particularly in diagnosis of peripheral lung diseases (PLDs). Although an underused tool in many centers, and despite inherent limitations in evaluation of central lung disease caused by high acoustic impedance between air and soft tissues, lung CEUS has emerged as a valuable tool in diagnosis of PLDs. Owing to the dual arterial supply to the lungs via pulmonary and bronchial (systemic) arteries, different enhancement patterns can be observed at lung CEUS, thereby enabling accurate differential diagnoses in various PLDs. Lung CEUS also assists in identifying patients who may benefit from complementary diagnostic tests, including image-guided percutaneous biopsy. Moreover, lung CEUS-guided percutaneous biopsy has shown feasibility in accessible subpleural lesions, enabling higher histopathologic performance without significantly increasing either imaging time or expenses compared with conventional US. The authors discuss the technique of and basic normal and pathologic findings at conventional lung US, followed by a more detailed discussion of lung CEUS applications, emphasizing specific aspects of pulmonary physiology, basic concepts in lung US enhancement, and the most commonly encountered enhancement patterns of different PLDs. Finally, they discuss the benefits of lung CEUS in planning and guidance of US-guided lung biopsy. ©RSNA, 2024 Supplemental material is available for this article.

The use of lung ultrasound in COVID-19

This review article addresses the role of lung ultrasound in patients with coronavirus disease 2019 (COVID-19) for diagnosis and disease management. As a simple imaging procedure, lung ultrasound contributes to the early identification of patients with clinical conditions suggestive of COVID-19, supports decisions about hospital admission and informs therapeutic strategy. It can be performed in various clinical settings (primary care facilities, emergency departments, hospital wards, intensive care units), but also in outpatient settings using portable devices. The article describes typical lung ultrasound findings for COVID-19 pneumonia (interstitial pattern, pleural abnormalities and consolidations), as one component of COVID-19 diagnostic workup that otherwise includes clinical and laboratory evaluation. Advantages and limitations of lung ultrasound use in COVID-19 are described, along with equipment requirements and training needs. To infer on the use of lung ultrasound in different regions, a literature search was performed using key words "COVID-19", "lung ultrasound" and "imaging". Lung ultrasound is a noninvasive, rapid and reproducible procedure; can be performed at the point of care; requires simple sterilisation; and involves non-ionising radiation, allowing repeated exams on the same patient, with special benefit in children and pregnant women. However, physical proximity between the patient and the ultrasound operator is a limitation in the current pandemic context, emphasising the need to implement specific infection prevention and control measures. Availability of qualified staff adequately trained to perform lung ultrasound remains a major barrier to lung ultrasound utilisation. Training, advocacy and awareness rising can help build up capacities of local providers to facilitate lung ultrasound use for COVID-19 management, in particular in low- and middle-income countries.

Incidental discovery of intercostal pulmonary hernia: A case report

Lung hernias are rare. They are defined by the protrusion of lung parenchyma through a defect in the chest wall. A distinction is classically made between supraclavicular, thoracic or diaphragmatic hernias and congenital or acquired hernias. The latter can be classified by etiology as post-traumatic, postoperative, or pathological but can be spontaneous (even rarer) caused mainly by coughing efforts. The diagnosis is guided by the clinical presentation and confirmed by radiographic analysis, especially CT scan. The management, by conservative or surgical approach, depends on the clinical condition of the patient, the characteristics of the hernia and the existence or not of complications. We report the case of a 58-year-old patient, chronic smoker with no history of trauma, who presented with a chronic cough not improved by symptomatic treatment and in whom the clinical examination was without particularities. Chest CT scan showed discrete pulmonary emphysema with an intercostal pulmonary herniation at the level of the right fifth intercostal space associated with a bony outgrowth at the level of the middle arch of the right fifth rib. The pulmonary protrusion occurred through a parietal defect between the fifth rib and the bony protrusion. The management consisted of conservative treatment of the hernia with close clinical and radiological follow-up and medical treatment of the pulmonary emphysema and chronic cough associated with smoking cessation and hygienic and dietary rules.

Ultrasound-guided interventional radiology procedures in the chest

Ultrasonography is a very good tool for guiding different interventional procedures in the chest. It is the ideal technique for managing conditions involving the pleural space, and it makes it possible to carry out procedures such as thoracocentesis, biopsies, or drainage. In the lungs, only lesions in contact with the costal pleura are accessible to ultrasound-guided interventions. In this type of lung lesions, ultrasound is as effective as computed tomography to guide interventional procedures, but the rate of complications and time required for the intervention are lower for ultrasound-guided procedures.

Validity of lung ultrasound to rule out iatrogenic pneumothorax performed by pulmonologists without experience in this procedure

INTRODUCTION

Ultrasonography has been shown to be a useful tool for diagnosing pneumothorax in the hands of experts. After performing bronchopleural procedures, the recommendation is to perform chest radiography to rule out complications. Our objective was to determine the validity of lung ultrasound, conducted by pulmonologists without experience in this procedure, to rule out pneumothorax after invasive procedures.

MATERIAL AND METHODS

Our prospective observational study consecutively included patients who underwent transbronchial lung biopsy (TBLB), therapeutic thoracentesis (TT) and/or transparietal pleural biopsies (PB) for whom subsequent chest radiography to rule out complications was indicated. In all cases, the same pulmonologist who performed the technique performed an ultrasound immediately after the procedure. A diagnosis of pneumothorax was considered in the presence of a lung point or the combination of the following signs: absence of pleural sliding, absence of B-lines and presence of the "barcode" sign.

RESULTS

We included 275 procedures (149 TBLBs, 36 BPs, 90 TTs), which resulted in 14 (5.1%) iatrogenic pneumothoraxes. Ultrasonography presented a sensitivity of 78.5%, a specificity of 85% and positive and negative predictive value of 22% and 98.6%, respectively. Ultrasonography did not help detect the presence of 3 pneumothoraxes, one of which required chest drainage, but adequately diagnosed 2 pneumothoraxes that were not identified in the initial radiography.

CONCLUSIONS

Lung ultrasound performed by pulmonologists at the start of their training helps rule out pneumothorax with a negative predictive value of 98.6%, thereby avoiding unnecessary radiographic control studies in a considerable number of cases.

Thoracic ultrasound in viral infections

Ultrasonography has proven useful in the study of many pulmonary diseases that affect the subpleural regions. This article reviews the current evidence regarding the role of ultrasonography in the diagnosis and management of viral lung infections. It describes the examination technique and the main ultrasonographic findings for different viruses that can affect the lungs.

Validity of lung ultrasound to rule out iatrogenic pneumothorax performed by pulmonologists without experience in this procedure

INTRODUCTION

Ultrasonography has been shown to be a useful tool for diagnosing pneumothorax in the hands of experts. After performing bronchopleural procedures, the recommendation is to perform chest radiography to rule out complications. Our objective was to determine the validity of lung ultrasound, conducted by pulmonologists without experience in this procedure, to tule out pneumothorax after invasive procedures.

MATERIAL AND METHODS

Our prospective observational study consecutively included patients who underwent transbronchial lung biopsy (TBLB), therapeutic thoracentesis (TT) and/or transparietal pleural biopsies (PB) for whom subsequent chest radiography to rule out complications was indicated. In all cases, the same pulmonologist who performed the technique performed an ultrasound immediately after the procedure. A diagnosis of pneumothorax was considered in the presence of a lung point or the combination of the following signs: absence of pleural sliding, absence of B-lines and presence of the "barcode" sign.

RESULTS

We included 275 procedures (149 TBLBs, 36 BPs, 90 TTs), which resulted in 14 (5.1%) iatrogenic pneumothoraxes. Ultrasonography presented a sensitivity of 78.5%, a specificity of 85% and positive and negative predictive value of 22% and 98.6%, respectively. Ultrasonography did not help detect the presence of 3 pneumothoraxes, one of which required chest drainage, but adequately diagnosed 2 pneumothoraxes that were not identified in the initial radiography.

CONCLUSIONS

Lung ultrasound performed by pulmonologists at the start of their training helps rule out pneumothorax with a negative predictive value of 98.6%, thereby avoiding unnecessary radiographic control studies in a considerable number of cases.

Ultrasonido pulmonar en Medicina, su utilidad en la práctica clínica

Lung ultrasound has become increasingly important in the evaluation of the thorax and its pathologies. It has proved to be very useful in the evaluation of hospitalized patients, allowing doctors to evaluate and make quick decisions, as well as providing guidance for diagnostic and therapeutic procedures. Ultrasound has many advantages over other studies since it can avoid transferring patients, and it is harmless, accessible and fast. In this article we will review basic concepts of lung ultrasound and its use in the diagnosis of pathologies. Key words: Pulmonary ultrasound; pleura; pneumothorax; pleural effusion.

Benefit of Chest Ultrasonography in the Diagnosis of Peripheral Thoracic Lesions in an Interventional Pulmonology Unit

INTRODUCTION AND OBJECTIVES

The use of ultrasound in peripheral thoracic lesions offers advantages over other radiological guiding methods. This diagnostic procedure has been applied in most studies published by radiologists. Our aim was to determine the diagnostic efficacy of percutaneous ultrasound-guided punctures and biopsies of peripheral thoracic lesions performed by pulmonologists.

METHODOLOGY

A retrospective analysis of 58 patients who underwent real-time ultrasound-guided transthoracic punctures and biopsy of peripheral thoracic lesions between March 2011 and September 2014 in the pulmonology department of our hospital. Cases were classified into the following diagnostic categories: malignant, benign and non-diagnostic (non-specific benign without evidence of malignancy and insufficient specimen).

RESULTS

A conclusive diagnosis was obtained in 47 procedures (81%), of which 13 (22.4%) were specific benign lesions and 34 (58.6%) cancers. In the remaining 11 (19%) patients, a non-diagnostic result was obtained [non-specific benign in 5 cases (8.6%) and insufficient specimen in 6 (10.3%)]. Sensitivity was 75.6%, negative predictive value was 54.2%, specificity and positive predictive value were 100%, and diagnostic accuracy was 81%. Excluding procedures with insufficient specimens, the results were 87.2%, 72.3%, 100%, 100% and 90.4% respectively. There were no serious complications.

CONCLUSIONS

Percutaneous ultrasound-guided puncture and biopsy in the diagnosis of peripheral thoracic lesions performed by pulmonologists is a safe procedure with high diagnostic accuracy. We achieved similar results to those previously obtained by radiologists.

[Utility of the lung ultrasound in the intensive medicine unit]

The radiological diagnostic approach of the thorax in the critically ill patient has traditionally been based on the anteroposterior chest X-ray. However, it is generally accepted that it has important limitations regarding its diagnostic accuracy of pleuro-pulmonary disease. The introduction of computed tomography largely solved this problem, but with the dual disadvantage of a larger radiation dose and the unavoidable transportation outside of the ICU. In this context, the lung ultrasound has become an alternative technique, with the advantage that due to its portability, it is done at the patient's bedside. In the lung ultrasound, the ribs, spine and air in the thorax act as barriers to the ultrasounds, causing artifacts that must be recognized and interpreted for a correct diagnosis. However, intrathoracic diseases, existence of fluid in the pleural space and consolidation, or atelectasis in the lung provide a sufficient ultrasound window for the correct evaluation. In this review, we explain the lung and pleural ultrasound technique, define the normal pattern and the artifacts that serve to detect the abnormalities and we explain the criteria for the main diseases (consolidation, pleural effusion, pulmonary edema and pneumothorax). We also discuss the possible utility and limitations of the lung ultrasound in our daily practice, such as diagnosis of acute respiratory failure, detection, quantification and drainage of a pleural effusion, chest trauma, management and complications of acute respiratory distress syndrome and tracheal intubation success or failure.