Page 273 - Feline diagnostic imaging

14.8 Lung Lobe Torsion 277
lesions, and typically this is only one part of a more sys- noted in cats with this disease. Secondary pulmonary
temic infection [78–80]. Small granulomas may involve the hypertension may develop, with accompanying right‐sided
pleura and underlying lung parenchyma. Involvement of cardiomegaly and pleural effusion. The radiographic signs
the pericardium, with pericardial effusion, may occur. can mimic feline asthma as well as diffuse pulmonary neo-
plasia (Figure 14.34).

14.6.5 Noninfectious Pneumonia
Lipid pneumonia is a noninfectious form of pneumonia 14.8 Lung Lobe Torsion
secondary to the accumulation of lipid‐filled macrophages
within alveoli and interstitial tissue. This may occur second- Torsion of a lung lobe occurs when it rotates around its axis,
ary to aspiration of petroleum‐based products (originally used and is typically secondary to some other underlying disease
for treatment of hairballs and constipation), or underlying such as pleural effusion, trauma, or thoracic surgery [86–
disease resulting in injury to pneumocytes and lipid accumu- 89]. Venous return is cut off, but arterial blood supply is at
lation [81,82]. Radiographic changes include multifocal distri- least partially maintained. The lobe becomes congested due
bution of patchy alveolar opacities, mixed interstitial and to edema, hemorrhage, and necrosis. Radiographic signs of
bronchial patterns, lobar consolidation, and/or discrete pul- lung lobe torsion include pleural effusion and persistent
monary nodules secondary to the granulomatous response. lobar consolidation with abnormally oriented or shaped air‐
filled bronchi in the affected lobe (Figure 14.35). Multiple
small gas lucencies (“vesicular emphysema”) have been
14.7 Pulmonary Fibrosis noted in some cases. The right middle and left and right cra-
nial lobes are most commonly affected.
Pulmonary fibrosis is a progressive fatal interstitial lung As noted in the previous sections, the radiographic appear-
disease due to deposition of excessive collagen in the place ance of pulmonary disease in the cat is rarely specific for a
of normal cellular components. The radiographic changes particular disease. Neoplasia, edema, pneumonia, and fibrosis
are variable [83–85]. Bilateral bronchial and unstructured can all have the same appearance and must be differentiated
interstitial patterns, along with interstitial nodules, alveo- by a combination of clinical signs, signalment, bloodwork,
lar opacities, bronchiectasis, and bullae, have all been and, most importantly, cytology/histopathology.

(b)

(a)

Figure 14.35 Lateral (a) and VD (b) images of a cat with chronic chylous effusion. After thoracocentesis, there was persistent
consolidation of the right middle lung lobe. Lung torsion was confirmed at necropsy.