Notebook: Radiology of Lung Disease 1

Radiographic technique: pull legs forward in left lateral position so that they're not super-imposed on the thorax. For VD projection, make sure the animal is straight. Exposure: use high KVP (reduces contrast, gives a lot of grayscale). Also, use a grid and try to take rads on full inspiration. This is important because we need something that contrasts the structures in the thorax. Also, always take 2 projections of each patient. This is important for best possible assessment because the recumbent lung will be collapsed.

- Anatomy: caudal vena cava is always on the right side.
- When evaulating chest rads: look at extra-thoracic structures first!

Now to the meat of the lecture: Pulmonary parynchema: pleural space, mediastinum, heart, vessels. In normal small animal lungs, the right lung is a bit bigger. Lumen of bronchi will always be black with very thin wall; mainly seen in perihylar area. Vessels are filled with blood. Connective/ interstitial tissue around big vessels and bronchi. Black lung with white lines, white vessels, thin parallel branching lines are the bronchi.

If there's a problem with the radiograph, rule out artifacts or extra-pulmonary diseases. Artifact: It may be that the rads weren't taken at full peak inspiration. Think of the animal's fat content. Legs may not be pulled fully forward.

Alveolar, bronchial, interstitial, vascular patterns and combinations of them.

Alveolar pulmonary pattern: fluid and cells on rad are white. So if all those alveoli are filled with fluid and the round structures are filled with soft tissue opacity, we don't see the difference between the vessels and the lung parynchema anymore. All we see is the air within the bronchi (black outline of bronchial tree). List things that indicate alveolar pulmonary pattern: soft tissue opacity, silhouetting with other soft tissue structures, air bronchograms, lobar sign. May indicate: pneumonia, edema, hemorrhage, atelectasis, neoplasia, torsion, infarct.