MDCT and US of intrathoracic extrapleural space soft tissue-containing lesions: US extrapleural fat sign and MDCT fat ghost ribs sign

"Multimodality imaging of the extrapleural space lesions"

Extrapleural space (EPS) is a potential space between the outer layer of the parietal pleura and the inner layer of the chest wall and the diaphragm. Many different pathologies including chronic inflammatory conditions, infections, trauma, neoplastic disease (both benign and malignant) as well as many infiltrative disorders can involve the EPS. It is one of the frequently overlooked entity on imaging due to relative lack of understanding of the anatomy and the imaging appearances of the diseases localized to this space. The knowledge of the EPS is essential for the radiologists as the pathologies which involve the EPS may require different treatment approach compared to pleural or parenchymal lung disease. Additionally, the EPS involvement may influence the staging and treatment planning for chest malignancies. In this review, we give an overview of the anatomy and various pathologies involving EPS, utility of different imaging modalities in the evaluation of EPS lesions with emphasis on cross sectional imaging and emerging technologies like spectral CT and its role in recognizing the imaging features which enable specific diagnosis of various pathologies.

Late Diagnosis of a Large Extrapleural Hematoma in a Patient With Stanford Type B Aortic Dissection: A Case Report and Review of Literature

Acute aortic dissection is a rare but catastrophic condition. When the dissection extends through the adventitia, blood can extravasate into the extrapleural or intrapleural spaces, causing an extrapleural hematoma or hemothorax. The early recognition of extrapleural hematoma and distinguishing it from hemothorax is critical because the management of those two entities is different. The authors present a case of a late diagnosis of a large extrapleural hematoma in a patient with Stanford type B acute aortic dissection that required thoracotomy for hematoma evacuation. The patient underwent successful thoracic endovascular aortic repair (TEVAR). Postoperatively, the patient had worsening pulmonary function, with a large fluid collection on imaging that was not drained by the thoracostomy tubes. Surgical exploration revealed a large extrapleural hematoma. Timely recognition of the extrapleural hematoma was key in the patient's clinical management. Without clear radiographic diagnostic features of extrapleural hematoma, unsuccessful drainage of hematoma after insertion of a chest tube may suggest an extrapleural hematoma or a clotted hemothorax. If patients continue to have circulatory or respiratory compromises, prompt surgical exploration should be considered. It is important for clinicians to be aware of extrapleural hematoma in complicated acute aortic dissection, especially when chest tube drainage of an apparent hemothorax is unsuccessful.

Extrapleural hematoma that was not detectable on initial CT in a patient with pneumonia

Extrapleural hematoma (EH) is an uncommon and occasionally life-threatening condition. Huge EH can cause potentially fatal respiratory and circulatory disturbances. The usual causes of EH are chest trauma, iatrogenic injury, and rupture of a thoracic aortic aneurysm. There have been few reports of EH as a complication of pneumonia. Here we describe a case of EH that was not detectable on initial computed tomography (CT) in a patient with pneumonia despite symptoms suggestive of hemorrhage. A 70-year-old man who had been diagnosed with pneumonia the previous day visited our hospital after developing right upper abdominal pain of sudden onset. Initial noncontrast-enhanced computed tomography (CT) showed consolidation of the right lower lobe of the lung but no hematoma. He was discharged from hospital. When the pain recurred the following day, he was transported by ambulance back to our hospital and admitted. Contrast-enhanced CT showed an EH that had not been apparent on the initial CT scan taken 33 h earlier. Coagulation tests were within normal limits. He was treated conservatively and monitored closely. His symptoms improved, and he was discharged 4 days after admission. The EH did not enlarge and had almost disappeared by 56 days after admission. The pathophysiology of the relationship between pneumonia and EH is unclear. This case suggests that EH cannot be ruled out by initial CT findings soon after an episode suggestive of hemorrhage and can occur as a complication of pneumonia. Therefore, patients in whom EH is suspected should be followed up closely.

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

An abnormal collection of air in the thorax is one of the most common life-threatening events that occurs in the intensive care unit. Patient management differs depending on the location of the air collection; therefore, detecting abnormal air collection and identifying its exact location on supine chest radiographs is essential for early treatment and positive patient outcomes. Thoracic abnormal air collects in multiple thoracic spaces, including the pleural cavity, chest wall, mediastinum, pericardium, and lung. Pneumothorax in the supine position shows different radiographic findings depending on the location. Many conditions, such as skin folds, interlobar fissure, bullae in the apices, and air collection in the intrathoracic extrapleural space, mimic pneumothorax on radiographs. Additionally, pneumopericardium may resemble pneumomediastinum and needs to be differentiated. Further, some conditions such as inferior pulmonary ligament air collection versus a pneumatocele or pneumothorax in the posteromedial space require a differential diagnosis based on radiographs. Computed tomography (CT) is required to localize the air and delineate potential etiologies when a diagnosis by radiography is difficult. The purposes of this article are to review the anatomy of the potential spaces in the chest where abnormal air can collect, explain characteristic radiographic findings of the abnormal air collection in supine patients with illustrations and correlated CT images, and describe the distinguishing features of conditions that require a differential diagnosis. Since management differs based on the location of the air collection, radiologists should try to accurately detect and identify the location of air collection on supine radiographs.

Primary pulmonary lymphoma: imaging findings in 30 cases

PURPOSE

To present our experience of cases of primary pulmonary lymphoma (PPL) found between January 2002 and July 2018, focusing on the radiological features and the differential diagnosis in order to contribute to the difficult role of the radiologist in the disease identification and to help the clinicians to reach the diagnosis.

MATERIALS AND METHODS

CT scans of 30 patients (14 men and 16 women, aged 58-86, mean age 72 years) with PPL were retrospectively reviewed. All patients had a histopathological confirmation of the disease: MALT lymphoma (23 patients, 76.6%); diffuse large B-cell lymphoma-DLBCL (seven patients, 23.4%). All the staging CT scans were evaluated by three experienced radiologists dedicated to thoracic disease in order to radiologically define the predominant pattern of presentation.

RESULTS

The following parenchymal patterns were observed: 11 patients with single/multiple nodules, five with masses/mass-like consolidations, 14 with consolidations with air bronchogram, 16 with ground-glass opacity, ten with angiogram sign, 22 with perilymphatic and/or peribronchovascular spread, 15 with associated lymphadenopathies, and 13 with pleural/chest wall involvement. The main characteristics of PPLs were the presence of consolidations and ground-glass opacities, with perilymphatic and/or bronchovascular spread.

CONCLUSION

All the characteristics of the work should alert the radiologist to consider lymphoma among the possible differential diagnoses, always correlating the results of the CT examination with appropriate clinical laboratory evaluations.