Rounded Atelectasis

Peripheral mass-like left lower lobe collapse which abuts a broad pleural surface with associated pleural thickening and a swirl-like appearance of vessels curving toward the collapsed area.     Diagnosis: Rounded Atelectasis

Atelectasis

• Diminished air in lung with decreased lung volume

• Not necessarily associated with radiopacity

• Classified by mechanism

  1. Resorption

  2. Cicatrization

  3. Adhesive

  4. Relaxation

Round Atelectasis
(See more examples in figures below)

• Type of relaxation atelectasis

• Associated with focal pleural thickening

• Develops in relation to pleural effusion, fibrosis

Imaging Findings:

CXR:

• rounded, wedge shaped subpleural mass

• usually in lower lobes

• gathering of bronchovascular bundles

CT:

• subpleural collapse with adjacent pleural thickening

• "Comet Tail" - with bronchi, vessels curving towards collapsed area

• air bronchograms

• subpleural fat

• hyperlucent adjacent lung

• decreased volume of affected lung

• calcifications within

  Causes:

• exposure to asbestos

• s/p pleural effusion from tb

• s/p therapeutic PTX

• s/p pulmonary infarct

• with uremic pleuritis

• Dressler's syndrome

• idiopathic pleural exudates

• malignant tumor

• malignant mesothelioma

Asbestos Related Lung Disease:

• With exposure to chrysotile, amosite, crocidolite

• In shipyard workers, pipefitters, installers of brake linings or insulation

• With pleural disease

  • plaques, thickening

  • malignant mesothelioma

• With parenchymal disease

  • asbestosis

References:

Armstrong, Peter, et al , Imaging of Diseases of the Chest, 3rd edition, (Mosby Publishing; London, 2000), pp. 97-98, 482.

Fraser, et al , Fraser and Pare's Diagnosis of Diseases of the Chest, 4th edition, (W.B. Saunders Company; Philadelphia, PA, 1999), pp. 513-522.

Papiris, S.A., et al , "Round Atelectasis and Metsovo Lung," Chest, volume 103, pp.1759-1762.