Multidetector CT for Evaluation of the Extrapleural Space

Abstract

The extrapleural space (EPS) is an anatomic space at the periphery of the chest that can be involved in a number of disease processes. This space lies between the inner surface of the ribs and the parietal pleura and contains adipose tissue, loose connective tissue, lymph nodes, vessels, endothoracic fascia, and the innermost intercostal muscle. It is often overlooked on cross-sectional imaging studies and almost invariably overlooked on conventional radiographic studies. At conventional radiography, the EPS occasionally can be seen when there is extrapleural fat proliferation, which might be confused with pleural thickening or pleural effusion. Knowledge of the normal anatomy of the EPS depicted at computed tomography (CT) and of the relationship of the EPS with parenchymal, pleural, and chest wall processes is key to the detection of extrapleural abnormalities. Disease entities that most commonly affect the EPS include chronic inflammatory disorders, infection, trauma, and neoplasms. Chronic inflammatory conditions and infectious processes of the lungs and pleurae induce adipocyte proliferation adjacent to the inflamed tissue, resulting in increased extrapleural fat. Chest wall trauma with extrapleural hematoma formation causes characteristic CT findings that enable differentiation of the extrapleural hematoma from hemothorax and warrant a different treatment approach. Extrapleural air is commonly seen in patients with pneumomediastinum and should be distinguished from pneumothorax because it requires a different treatment approach. Intrathoracic neoplasms can cause an increase in the attenuation of normal extrapleural fat owing to pleural inflammation, lymphatic obstruction, lymphangitic spread, or direct invasion by tumor. The normal and pathologic appearances of the EPS, as depicted at thoracic CT, and the differential diagnosis of findings in the EPS are reviewed. RSNA, 2017.

Thoracic abnormal air collections in patients in the intensive care unit: radiograph findings correlated with CT

“…It contains extrapleural fat, endothoracic fascia, and the innermost intercostal muscle (Fig. 1) [13,36]). The normal extrapleural space is not distinguishable as separate structures on CT images [13,36], and it can extend into the mediastinum [13].…”

“…1) [13,36]). The normal extrapleural space is not distinguishable as separate structures on CT images [13,36], and it can extend into the mediastinum [13]. Air collection in the extrapleural space is caused by barotrauma, disruption of the tracheobronchial and esophagus, and the extension of air from other space, such as the neck and retroperitoneum [13].…”

“…The normal extrapleural space is not distinguishable as separate structures on CT images [13,36], and it can extend into the mediastinum [13]. Air collection in the extrapleural space is caused by barotrauma, disruption of the tracheobronchial and esophagus, and the extension of air from other space, such as the neck and retroperitoneum [13]. Although this condition is usually managed with close observation, other treatments may be needed in cases of tracheobronchial tree or esophageal lesions [13].…”

“…Pneumothorax, especially tension pneumothorax, is treated by drainage [12]. Subcutaneous emphysema, air collection in the intrathoracic extrapleural space, and pneumomediastinum are usually not considered urgent conditions and often only require clinical observation [13][14][15]. However, in the case of abnormal air collection caused by tracheal/esophageal rupture, emergent surgical intervention may be required.…”

Traumatic Extrapleural Hematoma Mimicking Hemothorax

“…Rarely, chest injury may result in a collection of blood between the parietal pleura and the endothoracic fascia, named extra-pleural hematoma [3]. Extrapleural hematoma is often overlooked on conventional radiologic studies [4]. The authors report a case of traumatic extrapleural hematoma with a presentation similar to hemothorax.…”