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Radiology Case
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Radiographic findings: : There
is moderate dilatation of the left cranial bronchus. The bronchus ends
abruptly at the level of a rectangular shaped soft tissue opacity. It
is seen end-on on the VD view. On the lateral view, there is a focal 3
mm in diameter irregularly marginated faintly mineralized structure seen
at the junction of the aerated bronchus and soft tissue filled bronchus
which could represent a foreign body, although an artifact cannot be excluded.
There is mild generalized bronchointerstitial lung pattern. The cardiovascular
structures are normal. There is mild spondylosis at the T-L spine.
Radiographic impression: There is obstruction of the left cranial bronchus, by a suspected foreign body causing focal bronchiectasis. There is also a likely concurrent mild bronchitis.
Comments: Bronchiectasis is an irreversible dilation of a bronchus or bronchi, that can be diffuse or focal. The third to fifth order bronchi and the dependent lung lobes are most commonly affected. Focal bronchiectasis can be caused by multiple etiologies including foreign bodies, chronic granulomas, hilar lymphadenopathy secondary to bacterial or fungal infections, mucoid impaction of a bronchus, intramural or extramural bronchial neoplasms, and stricture of the bronchus. Aspirated bronchial foreign bodies can be a diagnostic challenge. If the episode is acute, and the foreign body non-radiopaque, there may be no radiographic changes.
Efficient collateral ventilation often prevents atelectasis of the lung
lobe. Also, if the obstruction is partial, it may act as a one-way valve
leading to hyperinflation of the lobe and a mediastinal shift. This amazing
safeguard in the lungs will allow air to get distal to an obstruction
and aid in the effort to cough out the obstruction. The right middle lobe
has very little collateral ventilation that predisposes it to collapse
in chronic airway or obstructive disease. If a bronchial foreign body
is suspected, bronchoscopy is indicated. If Actinomyces spp. is cultured
from the bronchial secretions, a bronchial foreign body should be suspected.
1
References
- Suter P, Lord P. Lower airway and pulmonary parenchymal disease. In: Suter P, ed. Thoracic Radiology, Thoracic diseases of the dog and cat.: Suter, PF, 1984;527-532
Dr. John Feleciano, DVM, DACVR
Dr. Renee Leveille, DVM, DACVR
