Lymphadenopathy is a common radiological finding in many thoracic diseases and may be caused by a variety of infectious, inflammatory, and neoplastic conditions. This review aims to describe the patterns of mediastinal and hilar lymphadenopathy found in benign diseases in immunocompetent patients. Computed tomography is the method of choice for the evaluation of lymphadenopathy, as it is able to demonstrate increased size of individual nodes, abnormalities of the interface between the mediastinum and lung, invasion of surrounding fat, coalescence of adjacent nodes, obliteration of the mediastinal fat, and hypo- and hyperdensity in lymph nodes. Intravenous contrast enhancement may be needed to help distinguish nodes from vessels. The most frequent infections resulting in this finding are tuberculosis and fungal disease (particularly histoplasmosis and coccidioidomycosis). Sarcoidosis is a relatively frequent cause of lymphadenopathy in young adults, and can be distinguished from other diseases - especially when enlarged lymph nodes are found to be multiple and symmetrical. Other conditions discussed in this review are silicosis, drug reactions, amyloidosis, heart failure, Castleman's disease, viral infections, and chronic obstructive pulmonary disease.

The presence of pulmonary nodules or mediastinal lymph nodes on the basis of preoperative chest MDCT scans in healthy children is frequent. Given that 95% of the nodules and 100% of the lymph nodes measured less than 6 mm and 7 mm, respectively, we conclude that incidental findings under these limits are very unlikely to be pathologic.

The adoption of a new threshold for fat content (<-33 HU) can lead to further improvements in the overall ability to detect PHs by CT.

In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI) has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation.

The authors report the case of an elderly woman assessed for dyspnea and right costal margin pain, whose chest radiography demonstrated opacity simulating pulmonary lesion, and computed tomography revealed the vascular origin of the condition. Acute aortic syndrome due to ruptured atheromatous plaque penetrating through the elastic lamina in association with aortic hematoma and aneurysm is a relevant differential diagnosis to be considered in these cases.