| Print Date: | June 18, 2013, 8:49 pm |
| Title | Peripheral left upper lobe collapse |
| Text | Chest radiographs are usually sufficient to diagnose the presence of lobar atelectasis and CT can be used when both pleural fluid and pulmonary disease is present. Obliteration or narrowing of the bronchial air column at the site of the obstruction is often visible. The fundamental signs of lobar atelectasis can be divided into (1) direct signs (displacement of fissures, pulmonary vessels and bronchi and (2) shift of other structures to compensate for the loss of volume. Compensatory overexpansion of the adjacent lobe can result in spreading of the vessels or shifting of the position of a granuloma.
In right upper lobe atelectasis, the normally horizontal fissure angles upward. The lobe is attached to the hilum by a conical wedge of collapsed lung and there is a inferior margin which connects to the hilum. Because the atelectatic left upper lobe contacts the mediastinum, the normal SVC border may be “shilhouetted” out. The middle and lower lobes expand leading to upward displacement of the interlobar artery. On the lateral view, the upward displacement of the major and minor fissures is easily seen. On rare occasions the normal chest wall contact is maintained even in serve collapse. This appearance is most often seen in neonates and young children, but can be seen in adults. This has been termed peripheral atelectasis because the atelectatic lobe lies against the lateral chest wall and the overexpanded lower lobe lies centrally. The appearance can be confused for a loculated pleural effusion but can be inferred from the volume loss and quick resolution. In peripheral collapse, the atelatatic lung lies adjacent to the lateral chest wall and has a well-defined medial border(formed by the major fissure). The intervening lung between the collapsed lobe and the lung hilus is somewhat opaque, but the usual wedge of unaerated lung extending to the hilus is not noted. |
| References: | 1) Armstrong P. Wilson AG. Imaging of Diseases of the Chest. London, Mosby, 1998.
2) Franken EA, Klatte EC. Atypical (peripheral) upper lobe collapse. Ann. Radiol., 1977, 20(1), 87-93. |
| Contributor | James H Chang (National Capital Consortium) |
| Peer Reviewer | David S. Feigin, M.D. (Johns Hopkins Hospitals) |
| Record Number | : 3550 |
| Created | 2002-01-12 12:42:33-05 |
| Modified | 2002-02-07 10:55:52-05 |
| Category: | Inflammatory, non-infectious |
| Location: | Chest, Pulmonary (ex. Heart) |
| Sublocation: | None Selected |
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