10/07/2024
Why is feline pulmonary cardiogenic oedema difficult to assess on radiographs?
Well…. it can have a quite a variable appearance and this complicates its radiographic diagnosis.
• In a study, by Benigni et al in 23 cats, cardiogenic pulmonary oedema was characterised radiographically by an increased pulmonary radiopacity associated with a range of patterns and variable distribution (Journal of Small Animal Practice (2009) 50, 9–14.DOI: 10.1111/j.1748-5827.2008.00655).
What they found:
•Increased Opacity:
Radiographically, there was a notable increase in lung opacity, often presenting with a reticular or granular interstitial pattern. This opacity can also include alveolar patterns, sometimes with air bronchograms, and an enlarged diameter of pulmonary vessels.
•Distribution Variability:
The distribution of pulmonary oedema varies significantly:
>It was diffuse/non-uniform in about 61% of cases.
>Diffuse/uniform in approximately 17% of cases.
> Multi-focal in 17% of cases, and focal in the remaining 4%.
•Regional Differences:
About 39% of cats exhibited regional distribution, with examples like ventral, caudal, or hilar distributions.
•Symmetry: Bilateral symmetry of pulmonary opacities was noted in only 22% of cats.
Cardiogenic pulmonary oedema cases are the cases that you don’t want to stress at all, and echocardiographic LA: Ao ratio may be used to confirm cardiac aetiology. Depending on your degree of suspicion, some clinicians may start a treatment trial with frusemide and repeat the thoracic radiographs in 24 hours to assess the lungs again.
Happier Imaging
Dr Hoff
