What abnormalities of the great vessels might be identified by routine radiography?
Radiography is a simple means to determine changes in the great vessels.
- Distention of the aorta in the region of the aortic arch with aortic stenosis:
- may not be apparent unless aortic stenosis (or subaortic) is severe
- Dilation of the main pulmonary artery (MPA):
- due to pulmonic stenosis, heartworm disease, or pulmonary artery hypertension
- Pulmonary over-circulation:
- left to right shunt
- Pulmonary under-circulation:
- right to left shunt
- Caudal vena caval enlargement:
- Caudal vena cava Present if the caudal vena cava is persistently of greater diameter than the descending thoracic aorta on the lateral view (normally they are roughly equal).
- Suggests right heart failure with elevated volumes in the caudal vena cava.
What radiographic features might suggest the presence of heartworm disease?
- Right ventricular enlargement
- Dilation of main pulmonary artery (MPA)
- Tortuosity of pulmonary arteries (PAs)
- Truncated PAs
- Enlargement of PAs
Can radiography diagnose pericardial effusion?
Radiography is useful to suggest a diagnosis of pericardial effusion.
- A very rounded (globose) enlarged heart is present; individual chambers cannot be visualized
- Pleural effusion is common (therefore, obscures the cardiac silhouette), ascites is common
- Pulmonary edema is usually absent, however pleural effusion obscures our ability to visualize the features of pulmonary edema.