Page 305 - Feline diagnostic imaging

310 18 Pleura

(a) (b)

(c)

Figure 18.6 (a) Lateral image of a cat presented for respiratory distress and elevated temperature. A large volume of pleural effusion
is present. Borders of the heart and diaphragm are effaced by the fluid. Pleural fluid can be seen surrounding the partially inflated
caudal lung lobes; the cranial and middle lobes appear more completely atelectatic. (b) Lateral image of the same cat after
thoracocentesis. Purulent fluid was obtained. A small amount of pleural fluid remains on the right side, causing a widened, radiopaque
pleural space (ventrodorsal view, arrow). A pneumothorax (likely iatrogenic due to thoracocentesis) results in enhanced visualization of
the caudal lung lobes (arrow). In addition, multiple rounded soft tissue opacities are visible dorsal to the sternum. (c) Ventrodorsal
image post thoracocentesis. A moderate amount of pleural effusion persists on the right side, resulting in a widened, radiopaque
pleural space (arrow). A poorly defined pneumothorax is present on the left side (seen better on the lateral image). Rounded soft tissue
nodular opacities cause border effacement of the right cardiac border. At necropsy, pleural fluid and multiple pulmonary, pleural, and
mediastinal abscesses were found. Rhodococcus equi was cultured.

reported to occasionally result in pneumothorax due to abscess, heartworm disease, eosinophilic small airway
hyperinflation and air trapping behind narrowed or con- inflammation, and bronchopulmonary dysplasia. It is sus-
stricted airways, especially during expiration. This results pected in many of these cases that the pneumothorax
in increased airway and subsequent increased alveolar results from ruptured bullae or leakage of air from diseased
pressures, which can eventually result in air leaking into pulmonary parenchyma and pleural surfaces [16–21]. CT
the pleural space [15,16]. may provide additional information regarding the source
Other pulmonary diseases reported to cause spontane- of the spontaneous pneumothorax, although it may not be
ous pneumothorax in the cat include parasitic infection, sensitive in the diagnosis of pulmonary bullae, at least in
neoplasia, pulmonary thromboembolism, pulmonary dogs [22].