Assessment of emphysema using high resolution CT, CT expiratory density mask, and plain chest films.

Pulmonary function tests (diffusing capacity for carbon monoxide of the lungs) and radiological imaging (plain chest film, high resolution computed tomography (CT) and CT expiratory density mask) were compared in the assessment of 29 patients with suspected airways obstruction. Conventional roentgenogram showed a good agreement with the diffusing capacity of the lungs and proved to be useful in predicting the presence of severe emphysema, but the extension of the disease was more precisely assessed by computed tomography. A good agreement was found between high resolution CT and density mask CT, although the "subjective" high resolution identified more patients with mild emphysema than the "automated" density mask. In conclusion, although the plain chest film is useful in the diagnosis of severe emphysema, CT (especially when high resolution is used) is helpful in identifying cases of mild disease and in diagnosing the type of emphysema.

[Rounded atelectasis of the lung]. / Atelettasia rotonda del polmone.

Rounded atelectasis is an uncommon but increasingly recognized form of pulmonary collapse that often mimics a pulmonary neoplasm. It is suggested that these lesions can occur many years after exposure to asbestos or exudative pleural effusions. The authors report 16 cases of rounded atelectasis seen during a period of over 10 years, 9 of which in the last 18 months. They describe the plain film, tomographic and CT appearances of the lesion. The radiographic features that allow a diagnosis are rounded or oval shadows lying along the posterior surface of the lower lobe, adjacent to thickened pleura. Lateral tomography and CT show the blood vessels and bronchi curving toward the mass and converging on one edge, like a comet tail. Differentiation of rounded atelectasis from neoplastic disease is essential in avoiding unnecessary thoracotomy.